I want to tell you about a debate I had last week. One that I lost.
As part of the new year 10 Physics course we have to teach the topic of gears. What do I know about gears exactly? Well, until last week I didn't even realise they came in different sizes. I don’t even know how to ride a bike. Technically I learned when I was eight but I’ve tried to do it since and failed every time. I know this is supposed to be impossible – to forget how to ride a bike - but I’m a special case of spatial incompetence. The old adage “it’s just like riding a bike” is one I only understand in theory.
But I digress.
In preparation for teaching this new topic I was trying to learn about gears, how they operated, what the different types were etc. and I came across a fiendish online puzzle showing a series of intersecting gear wheels and screws. The question was whether it would turn or not. I was pretty confident it would, one of the other teachers in the room was confident it wouldn’t. And thus the debate began. Here's the puzzle:
The movie adaptation of this thrilling battle of minds will be hitting cinema screens in 2018 with Charles Dance playing me and Daniel Day-Lewis playing the other teacher. Michael Bay is interested in directing.
Sure, a debate about interlocking gears is probably not the most exciting blog I’ve ever written, but these debates always seem thrilling when you’re in the middle of them don't they?
I was confident the system would work and he was confident it wouldn’t. They key thing is that we were both Scientists so only one thing mattered: what does the evidence say?
When two Scientists disagree it’s not about opinion or who is the “authority”. For example, he was a Biology teacher and this was definitely a Physics question. I could have been a jackass about it and assumed I was correct "because I'm the Physics teacher", but that would be a rookie error. There is no such thing as authority in Science – only evidence.
Consider the story of Hugh Longuett-Higgins; the 19 year old who solved the structure of diborane as a homework task. I love that story because it reminds me that Science is willing to accept an idea from anyone, even an unheard of teenager, if their hypothesis matches the evidence. Science isn't interested in prestige and it certainly carries no weight in a debate.
Even referring to a disagreement in Science as a “debate” isn’t appropriate. A debate implies two opposing sides trying to convince each other they've got it wrong and in Science we try and avoid this kind of thing. The term for a Scientific disagreement is a “dialectic” - where two sides try and find the truth together, both accepting the possibility they could be wrong. I find it yields results far more often.
So we began discussing the problem and fairly early on I said something along the lines of “I acknowledge what you’re saying but I’m not convinced by it.” The other teacher responded by saying “well, let’s see if the evidence will convince you.” In the movie this exchange will be delivered during a gun-battle in space.
And this is the crucial thing: any Scientific conflict can be resolved by testing a claim and seeing where the evidence lies. Rather than saying “I just think you’re wrong” or “shut up and get out of my face”, Scientists know it’s unwise to reject someone’s hypothesis because we don’t like it. Instead, we test their claim and see if it holds up.
To get the solution, we began discussing the problem, sketching it from different angles and seeing what would happen. At one point he even created a makeshift model out of kitchen-paper and board-pen to help me visualise the rotations involved (seriously, this movie’s going to be a hit). I have to be honest, by this point everyone else had left the room – but we’re both geeks so we can’t let these things go.
Eventually, he began quantifying his argument using a few simple bits of math and the light began to dawn in my head. My interpretation was completely wrong because I was failing to visualise some basic gear-laws. It took about twenty minutes for him to get me there but once I realised my mistake it took about five seconds for the Eureka moment to occur. And he was completely right. The above gear system will not work.
I didn’t feel bad once I realised how wrong I was however and he didn’t gloat, because in Science we understand (or at least try to) that whoever is right or wrong is largely irrelevant. All that matters is finding the truth.
And here’s the moral of the story...by realising I was wrong I learned something about gear relationships. Also, you probably don't want me fixing your car. Ultimately, I'm glad I got it wrong because I would have carried on blissfully incorrect otherwise. What I’m saying is that in Science you never really “lose”, you just learn.
That sounds like I’m trying to protect my ego and avoid admitting failure but I’m really not, I’ll be as blunt as possible: I got it totally wrong and failed to solve a problem in my own subject! I’m fine confessing that. But in making my mistake, I learned something I had overlooked and that can only be a good thing.
As Scientists we have a duty to follow evidence wherever it leads, even if that means admitting we backed the wrong horse. This can be difficult. We’re human and we like to think we’re clever. Indeed, I’m guilty of being stubborn and digging my heels in, but being a Scientist means trying to hold yourself to a higher standard. Admitting when you’re wrong is just a form of self-improvement.
To finish, here’s a wonderful story told by Richard Dawkins, found in in chapter 2 of Unweaving the Rainbow:
One of the formative experiences of my undergraduate years occurred when a visiting lecturer from America presented evidence that conclusively disproved the pet theory of a deeply respected elder statesman of our zoology department, the theory that we had all been brought up on. At the end of the lecture, the old man rose, strode to the front of the hall, shook the American warmly by the hand and declared in ringing emotional tones ‘My dear fellow, I wish to thank you. I have been wrong these fifteen years.’
If that isn't a description of Scientific integrity I don't know what is. Now I'm going to go and learn how to ride a bike.
The puzzle: cgtrader
Epic battle: acharif
10 is a magic number...apparently
The number of Science books I've treasured over the years - books which have genuinely changed my life - is pretty large. There's a part of me which wants to bang on about each one of them but I know everybody would fall asleep. Unfortunately, we humans have become acclimatised to "top 10" lists (thanks a lot Buzzfeed) so I decided it was necessary to play ball with human psychology and stick with 10 titles only. This means narrowing down many year's worth of reading material to a mere handful. This proved difficult.
Every time I settled on a list, I felt I was cheating the books which didn't make it. Besides, what happens if I bump into the author of one of the rejected books at a dinner party and they immediately grill me on why their book didn't make it (they follow my blog obviously). After the verbal attack, they throw a carefully prepared vial of sulfuric acid in my face before killing my houseplants and stealing my shoes. What do I do then?? In order to cover myself, I decided to impose some strict rules.
1. No text books.
Contrary to popular belief most Scientists don't sit around reading textbooks. We usually read the chapters we're interested in and treat the rest as a reference. Having said that, there are a few textbooks I have a fondness for (don't pretend you're shocked, I teach Science for a living, I'm a geek and proud).
Engineering Mathematics by K.A. Stroud is the best Maths textbook in the world. Biophysical Chemistry by Alan Cooper and An Introduction to Quantum Theory by P.A. Cox are also fantastic reads which you can get through in a week.
I also need to mention my very first Science book, loaned to me by my Chemistry teacher at the tender age of 14: Valency and Molecular Structure by Cartmell and Fowles (I'm pictured reading it in the above picture...obviously not at the tender age of 14).
2. No biographies
A good Scientist biography manages to teach some Science as it goes, but these aren't really Pop-Sci books. They’re just books about remarkable people. In this category I recommend Surely You're Joking Mr. Feynman by Ralph Leighton. Genius by Paul Gleick and A Primate's Memoir by Robert Sapolsky.
3. No Tech-Pop Books
These books are a hybrid of academic textbook and layman's guide. Written for non-experts who are still mathematically and Scientifically confident, they are essentially "Popular Science with the equations left in". If you're up for the challenge I recommend The Theoretical Minimum Series by Leonard Susskind, Six Not-So Easy Pieces, Tips on Physics, The Lectures on Physics Volumes I,II & III (all by Richard Feynman) and, if you've got the time and will-power, The Road to Reality by Roger Penrose.
4. No books by the same author
Obviously the best Science authors write many books. I decided to aim for a broad spectrum of topics and styles, so I had to avoid including the same author twice unless absolutely necessary (as you will see, it did turn out to be necessary)
So, with my rules laid out, here are my top 10 picks for best popular Science books that will make you a better person.
10. What If? by Randall Munroe
In What If? the cartoonist and engineer Randall Munroe considers ludicrous questions and answers them with real Scientific principles, teaching the reader as he goes. It's one of the cleverest strategies I've ever seen. For example: how high should you drop a steak through the atmosphere in order to cook it from air-resistance? Rather than dismissing it, Munroe goes to great lengths explaining the physics of falling, the chemical composition of meat, how cooking works and so on, until you've found the Science more intriguing than the ludicrous starting point. Munroe's sardonic and hilarious approach makes mechanics seem cool and trendy, which is not always easy to do.
9. The Selfish Gene by Richard Dawkins
Say what you like about Dawkins' fiery brand of atheism, as a Science writer he is unparalleled. The Selfish Gene is not, as the title suggests, a book about selfishness being genetic. It's about the nature of genes themselves and how unexpected behaviours arise as a result of Biological information. Why did humans evolve a capacity for kindness? Why do we take revenge? Why do some species choose aggression and some choose peace? In this powerhouse guide to evolution, Dawkins highlights what modern neo-Darwinism really says and why it's so powerful. Be warned though, it's not a casual Sunday-afternoon read. Dawkins is a fiercely intelligent man and he expects the reader to work hard. But the rewards are numerous.
8. Bad Science by Ben Goldacre
We live in a frightening age, where pseudoscience is often disguised as the real thing. Ben Goldacre swoops to the rescue in this antidote to media-manipulated Science stories and takes a look at the very nature of Popular Science itself. He examines homeopathy, spiritual healing, the MMR-vaccines hoax and nutriotinism, scrutinising everything with brilliant skepticism. But it's not a snarky book designed to attack people for believing dumb stuff. On the contrary, Goldacre considers "the person on the street" to be intelligent, sensible and capable of drawing informed conclusions (as do I). It's the Science-media charlatans who are the real villains here and Goldacre exposes them with aplomb and humour.
7. The Blank Slate by Stephen Pinker
This one is a very controversial choice, and I've included it for the debates it raises if nothing else. One of the most important questions in Science and Philosophy is: how much of our behaviour is the result of upbringing and how much is the result of genetics? The infamous "nature vs nurture" question. Most people, after grappling with the issue, decide that this is a false dichotomy, or that it's a 50:50 mixture and let's be done with it. Pinker, on the other hand, fearlessly tackles the issue with neuroscience, providing honest, if sometimes shocking (even disturbing) answers. Be warned, not everything he claims necessarily holds up and a lot of his reasoning is easily debunked. I didn't agree with a lot of what he said, but if you want to see what a real debate about evidence looks like, start here.
6. The Tell-Tale Brain by V.S. Ramachandran
Ramachandran's book is about a similar issue to Pinker’s (why humans are like this) but while The Blank Slate is a sharp and imposing read, The Tell-Tale Brain is a feel-good romp of surrealism and wit. Ramachandran is a serious physician who makes significant contributions to neuroscience, but as a writer he is irreverent, mischevious and cheeky. The Tell-Tale Brain is a look at some of the weirder things the brain does and how these phenomena give us clues to the big questions about consciousness. This is one of those jaw-dropping books which has you constantly going "that can't be true!" as Ramachandran details the strangest fringe-cases of brain activity in modern history.
5. The Black Hole War by Leonard Susskind
Leonard Susskind is one of the most intelligent people on the planet (that's not hyperbole, I mean that literally and can back it up). Having worked as Richard Feynman's accomplice, it's rather fitting that he inherited Feynman's skill for teaching difficult Physics concepts without the need for complex mathematics. What Susskind does in The Black Hole War - a very recent read - is to explain the complete landscape of modern theoretical physics including Quantum Field Theory, General Relativity, Black Hole Cosmology, String Theory, The Information Paradox, Quantum Thermodynamics and all the other cool things you’ve heard about. Susskind is able to explain these fiendish concepts in such casual detail you feel he's telling you how to make a cheese sandwich. As someone who spends his life trying to teach people Science, The Black Hole War had me slapping my forehead endlessly and thinking "why didn't I just say it like that?!"
4. Words of Science by Isaac Asimov
Throughout his career, Asimov wrote and edited over 500 books. Picking the best of his numerous works is tricky, but I decided to go with this one, mostly because it's so strange. Asimov described it as the most unusual book he'd written and I struggle to think of anything even remotely like it. The idea is simple enough. He goes through hundreds of Scientific words and explains where they come from. Put like that, the book sounds plain, even boring. But don't be fooled. Asimov's unique clarity and passion for storytelling makes the book whizz by and when you get to the end you're hoping for a sequel (which he did write). For someone just beginning their Scientific journey, the lingo can be tricky to grasp, so Words of Science is a fantastic jargon-buster which explains what Scientists are actually talking about.
3. Cosmos by Carl Sagan
Written to accompany what is, in my estimation, the greatest non-fiction television show of all time, Carl Sagan takes us on a tour of the Universe and gives the reader a view of what Science is all about. It also happens to be the most poetic non-fiction book ever written. Sagan's writing is so relaxing, majestic and powerful, you begin to see the Universe through his eyes and it is beautiful. Guiding you through everything from relativity to DNA to the brain, Sagan achieves something remarkable: rather than telling you a bunch of facts, Cosmos makes the story of how we made each discovery central. While Asimov’s Words of Science is a fantastic introduction to the language of Science, Cosmos is a fantastic introduction to its achievements.
2. QED by Richard Feynman
Feynman's nickname at CalTech was "the great explainer". In 1979 he was given a rather tough challenge: deliver four lectures, pitched at complete non-experts, on the topic of quantum electrodynamics. Would it be possible to explain one of the most complicated and strange theories in theoretical physics to people who had never attended freshman physics courses? If anyone was up to the task it was Feynman.
Not only did he succeed, Q.E.D. has become one of the standard introductory books on quantum mechanical theory even by expert standards. It is a triumph of explanation because both the layman and the expert can read it and find themselves gaining new insight and understanding. Feynman never dumbs down, never simplifies and never distorts, he just explains perfectly. Whether you're a professional or a beginner, Q.E.D. will open your mind to the weirdness of the world.
1. The Demon-Haunted World by Carl Sagan
I can only state it simply: The Demon Haunted World is the best book about Science I've ever read.
Fire from the Gods
In my last blog, I talked about Scientific discoveries from 2016 which have the potential to change the world. But that got me thinking: what was the very first Scientific discovery which shaped our destiny? The answer, I'm going to argue, was the discovery of fire. Nobody knows when we figured it out, but remains of man-made fires have been found dating back at least 400,000 years. We've been Science-ing for quite some time.
Whatever method we used and however it was discovered, the invention of fire marked a watershed for humans because it allowed us to do things no other animal could. For example, early humany creatures were tree-dwellers because the ground was where the predators lived. Once we mastered fire however, we had the ability to scare other creatures off (even hunt them), and spend time on the ground, encouraging us to walk on hind-legs which changed our physiology. It also kept us warm, meaning we could expand into colder regions, gradually colonising the land and spreading out from Africa across the globe.
Not to mention the ability to cook. It sounds like a small thing but cooking meat wasn’t just about taste. Cooked meat is easier to digest so fire allowed us to increase the calorie-content of our diet, which helped our brains grow...and that's been pretty good for us. Cooked meat also lasts longer, which helped us store it for the winter months. While other species froze to death, we were able to keep ourselves healthy and fed. There’s even evidence that early humans were using fire to treat metal spears, giving us an advantage in hunting. Ever tried to take down a mastadron with a fragile spear? Exactly.
Whether it was helping us defend ourselves, expand our territory, get better food, stay warm, get healthier or increase our brain-pans, fire was one of the most important Scientific discoveries in history. The first and last word in primitive Chemistry. It may even be the reason we got such a head-start in the first place. It therefore seems only right to pay tribute to this mysterious and wonderful reaction. The classic story of Prometheus stealing fire from the Gods to give humans an edge may have some grains of truthiness! For his troubles, Prometheus was chained to a rock where a hungry bird devoured his liver for all eternity.
What is fire?
First off, fire isn’t a substance. While some of the early Greeks believed fire was one of the elements, we now know it isn't an actual "thing". You can’t store fire in a box or pack it away when you’re done with it. It’s a chemical reaction taking place between two chemicals: oxygen and any chemical that will react with it. We call this other chemical a fuel. Since the air is about 20% oxygen, there’s always a good supply, the only challenge is making it react with whatever we’ve chosen as our fuel.
Oxygen and fuel chemicals don’t normally react, which is fortunate because everything (including you) would spontaneously burst into flame. To get a fire going the oxygen and fuel particles need to collide at high speeds so they can break each other up and rearrange to form new substances. In order to get a fire started you need to increase the speed of the particles which is Chemist-speak for “heat them up”.
Temperature is a measure of how fast your particles are moving on average, so raising the temperature is really giving your particles enough energy to get going. And there’s all sorts of ways to do it.
Rubbing the fuel very fast will work e.g. scraping two bits of dry wood past each other. So will striking pieces of sharp rock. The sparks which come flying off are tiny specks of rock, rubbed so fast they start heating up and reacting with the oxygen. Sparks are miniature fires of their own, and if you get a few dozen of them near something like dry grass, the heat can be transferred and things get going.
Once you’ve put enough movement in, the reaction begins as the fuel and oxygen shatter into each other, creating a chaotic, whirling cloud of particle splinters. Like a battle between a billion microscopic star ships, the fast-moving debris of fuel and oxygen doesn’t last long. The molecular scraps will recombine in new arrangements as they cool, releasing their energy in the form of light. This seething mess of molecular-war is a fire.
Why are fires "fire coloured"?
The shapes and sizes of different particles floating in the fire will cause different coloured light to be released, leading to different flame colours. A lot of fuels like paper and petrol contain carbon. If there’s not much oxygen around a lot of these carbon atoms don’t get used in the reaction and clump together, forming soot. When soot gets hot the heat energy it absorbs is spat back out as yellow, giving us the familiar glow we recognise in common fires. But other fuels release different light.
If you use copper sulfate the flame will be green. Switch it to copper chloride and you get electric blue. Lithium chloride burns pink and magnesium burns brilliant white with a rainbow edge. Wood contains a lot of the element sodium (the same chemical used in street lamps) which gives out orange light as it heats up, which is why wood fires are the same colour as street lamps.
Of course, if you mix your carbon-based fuel with oxygen before the particles reach the source of heat, the reaction is more efficiently mixed and you don’t get much soot forming (because the carbon is all smushed in with the oxygen). These kinds of fires, called pre-mixes, glow blue.
That’s why the flame on an oven hob is usually blue at the base. There’s hardly any soot being formed. As it gets higher however, there’s a less perfect carbon : oxygen ratio and soot starts to form, making the top of the flame yellow once more.
What gives a flame its shape?
The shape of a flame is the result of temperature differences and gravity. Something you’ve probably heard at some point is that heat rises. Not true unfortunatley. There’s something much stranger going on. When a group of molecules get hot they start flying in all directions, meaning a hot gas will expand as the particles spread out.
But there’s something else we need to factor in. Every particle is also being pulled toward the earth by gravity. Hot gases and vapours, like those in the flame, are moving fast enough to fly in ALL directions, including upwards, but the surrounding cold air doesn't have this option. Cold air doesn’t have enough movement in its particles to escape gravity, so it has no choice but to gradually sink. This means a cold gas can only fall, whereas the hot gas is able to trade places with it.
The cold air falls and forces the hot air upward because that’s the only place left for it to go. It’s not really hot air which rises, it’s cold air which falls better. Now let's consider our flame. We’ve got a bunch of hot gases and vapours tangling round each other. The cold air is constantly being pulled down and clumping at the bottom of the flame, where it suddenly gets heated up by all the fast moving (hot) chemicals already there. This means oxygen is constantly being pulled down into the flame.
As the chemicals are heated, they are forced up by the constantly sinking cold air, but by the time they’ve gotten a few inches away from the fuel source they’re moving too slowly to keep reacting, so the flame won’t go on forever, and it dies out at the top. These combined effects of gravity, cold air sinking and oxygen being sucked in, give us the familiar tear-drop shape of a controlled fire.
If you create a flame in a place where gravity isn’t behaving in the usual way however, it won’t be the usual shape. You can actually create spherical flames in a spaceship because the gravity is constantly changing direction as you move around the earth.
Why are fires hot?
Remember earlier when we said that when chemicals rearrange they often give out light? Well not all of that light is in the visible region. In fact, a huge amount of it comes out in the form of infra-red light, which our eyes can't see, but which cause molecules to vibrate. In other words, the chemical reactions in a fire tend to give out heat rays. These heat rays transfer energy from the chemical reaction to the surrounding molecules in a process called "radiation".
There's also the fact that particles in the fire are moving fast and battering into the surrounding air, making them move faster too. This hot air hits your hand and your skin absorbs the shock, which you interpret as heat. This process is either called convection or conduction (depending on circumstance).
Different chemicals will give out different amounts of energy when they react with oxygen, so different fuels will produce different flame temperatures. Jet fuel, for example, burns at around 800 degrees C, while an acetylene torch burns closer to 3,500 and a bunsen-burner flame at 1,500.
Why does water extinguish fires?
To stop a fire we’ve either got to remove the fuel, remove the oxygen, or stop the particles vibrating fast (cooling it down). If we put a lid over the flame or squish it between our fingers, we’re cutting out the air supply and removing the oxygen. You’d think, therefore, that water should keep a fire going because every water particle contains oxygen. But obviously the reverse is true for some reason.
Every water particle is made from an oxygen atom bonded to two hydrogen atoms and the bonds between these atoms are incredibly tough to break. The bonds in a petrol particle are very weak by comparison. You only have to get petrol up to about 126 C in order to make it catch. Water just keeps absorbing the energy with no sign of the bonds breaking, making it an excellent heat sponge. In order to burn water you have to heat it to about 12,000 C, anything below that and it will just vibrate faster.
If you put water on a fire, the water molecules absorb the vibrations from the fuel and oxygen, meaning the fuel and oxygen molecules lose their speed, killing the reaction and stopping the fire. The water you throw on a fire will definitely heat up a little itself, but not enough to split the oxygen from the hydrogen.
Why does blowing on a fire put it out...but also start it?
If you blow on a flame gently, you’re supplying oxygen and a little bit of movement (heat) to the fuel so it can start breaking up. If you blow hard and fast you do something else. Provided the gust of air coming from your mouth is bigger than the flame, you end up making the fuel and oxygen spread out in all directions. They get thrown out into the surrounding air and immediately lose their energy to the particles there. Without that tight mixture of fuel, oxygen and movement, the flame can’t keep going.
And the mysteries continue
It's worth finishing off by saying that a lot of fire Chemistry is still unknown to us. The above explanations are simply our best theories, but there are many aspects of fire which are still unaccounted for. It was out first big breakthrough, it's still an area of much debate and discussion. Viva la Science.
P.S. Fire conducts electricity
Electric Six album: Junostatic
Prometheus Movie: amazonaws
Burning Man: business insider
Spherical Flame: cloudfront
Chris Evans: becoming the muse
No need to feel down
It’s been an interesting year hasn't it? England chose to sever its ties with the European Union and America decided to elect a former celebrity-businessman as the new president. Many famous and talented people died including Vera Rubin (discoverer of dark matter), Walter Kohn (inventor of density functional theory) and of course, Lemmy (inventor of Motorhead). Alright, technically Lemmy died in 2015 but the pain's still real for me.
And, as if all this death wasn’t enough, we had the killer-clowns, the Dakota access pipeline fiasco, exploding phones, and I had to organise a school trip to London.
But while the news has been dismal and grim and miserable and doom-spreading (as it usually is) Science has made some awesome, uplifting, optimistic and life-changing discoveries (as it usually does).
There may be tough times ahead for Scientific literacy (link here) but we can never lose hope in the ingenuity and brilliance of our species. So, for the sake of everybody’s sanity, let’s take a moment to acknowledge the inspiring, mind-bending or just plain fascinating stuff Science and Technology achieved in 2016. In approximately chronological order.
Planet 9 (January 20th)
Michael Brown is the man responsible for demoting Pluto to dwarf-planet status (rightly so). But for those who objected, don’t hate the man too much - he's just brought the concept of a 9th planet back, only this time it's a lot bigger. Brown published data this year showing how some of the asteroids in the Kuiper belt are being pulled at a strange angle by some enormous mass floating in the darkness. We don't know what it is, but there's a very good chance we could be on the brink of discovering a whole new planet...ten times the size of Earth. None of your wussy Pluto nonsense. #planetFeynman #planetSagan #planetAsimov
First Human Thought Transplant (February 10th)
This story was overshadowed by gravitational waves the following day, but I considered it one of the most remarkable discoveries of the year. Thought transplants had been achieved with mice in 2013 by Susumu Tonegawa at RIKEN-MIT, and in 2016 Matthew Philips of HRL laboratories reported the first human version. By recording the electrical activity of a pilot’s brain, Philips was able to effectively ‘beam’ thought-patterns into the brains of people learning to fly aeroplanes. The research showed that students receiving these ‘thought-beams’ picked up the skills much faster than the control group. It’s hardly The Matrix but it’s an exciting step.
Gravitational Waves Discovered (February 11th)
Physicists at the LIGO observatory announced the long-anticipated discovery of gravitational waves. I’ve done a video explaining it here, but the short and tall is that not only do gravitational waves confirm a century-old theory, they open up a new era of cosmological exploration. Probably the "biggest" story of the year - certainly one that future history books will record.
Humans and Neanderthals Interbred (February)
In mid-February (appropriately around Valentine’s day) we discovered, thanks to Sergi Castellano of the Max Planck Institute, that early humans were having sex with Neanderthals about 100,000 years ago. This is interesting because Neanderthals mainly occupied Europe and humans, it was thought, were still hanging around in Africa. To find human DNA in the Neanderthal genome suggests we may have left Africa a lot earlier than people thought, changing what we know about human evolution.
Stem Cells for Stroke Patients (Early June)
Gary Steinberg of Stanford University published preliminary findings on the use of stem cells in stroke-victim therapy. Although the results are moderate and involve only a dozen patients, the use of stem-cells seems to have led to record-breaking recovery times for stroke victims, particularly in helping them regain mobility. Also, I have a confession to make regarding the picture above: the caption isn't true. Nobody enjoys the novels of Nicholas Sparks.
Biological Life After Death (June 11th)
This was another criminally under-reported study led by Alexander Pozhitkov at the University of Washington. While studying the death of mice and zebrafish, Pozhtikov discovered that death is not necessarily the end, in fact, for some parts of the body it is the beginning. Certain genes, associated with birth, cell-growth and cancer, are actually switched on 24 hours after the host organism dies. We have no idea why.
Juno Enters Orbit (July 5th)
After a five-year journey, the Juno probe successfully entered a stable orbit around Jupiter. Over a period of 37 rotations, the probe will gather data on the gas giant before its descent into Jupiter’s atmosphere (February 2018). This will give the human race our first glimpse inside a gas-giant planet. Hooray for Juno (the probe, not the Ellen Page movie).
Proxima b (August 24th)
In January, the European Southern Observatory launched the Pale Red Dot program to investigate the possibility of a planet orbiting our Sun’s nearest neighbour. On August 24th, they confirmed that not only does Proxima Centauri have a planet going around it, Proxima b, but it sits smack-bang in the goldilocks zone (more explanation here). In other words, rather than having to scour the Universe, it turns out there is a potentially habitable world in the next star-system! If only we had the means of getting there…
Breakthrough Starshot (April 12th)
I know this one should go earlier in the timeline, but it seemed like a nice way of linking the two stories. Mark Zuckerberg and Stephen Hawking announced the beginning of project Breakthrough Starshot, a new type of spacecraft based on solar-sail technology which, when built, will be able to reach Proxima b in 30 years, rather than the proposed hundreds of years it would take using conventional fuel-rockets.
Three-Parent Baby (September 27th)
Researchers led by John Zhang of New York helped deliver a baby boy containing genetic material from three adult humans. The couple who underwent the procedure suffered from a rare genetic disease which they would have passed to their son. By carefully altering the child’s DNA, Zhang was able to introduce DNA from a third parent and create a perfectly healthy baby, opening up a new realm of possibilities for parents who would otherwise be unable to have healthy children.
Robot Arm which can Feel Touch (October)
Nathan Copeland, who was paralysed after a road accident, volunteered for a revolutionary new technique in which a robot arm was wired directly into his brain. Not only does this arm respond to his thoughts and move as if it were his own, it feeds back sensory information, giving him back the sense of touch. I wanted to make some reference to the Transformers movie here about "you got the touch" but I realised there was a more obvious comment to make. We have just given a human being a fully-working, fully-sensing cybernetic limb.
First Successful Paralysis Cure (November 9th)
As if giving a paralysed man his sense of touch back wasn't enough, we've also made our first breakthrough in curing paralysis altogether. I'm not joking. Gregoire Courtine was able to successfully restore movement to previously paralysed monkeys by implanting wireless devices into their central nervous systems. One implant sits inside the brain of the monkey and wirelessly transmits a signal to the other implant in their legs, allowing the signal to bypass the damaged spinal column entirely, creating a newly reanimated cyborg-monkey! Human trials are a long ways off, but Courtine’s team has begun preparation at the CHUV University Hospital of Lausanne.
The EM-Drive Might Work (November 17th)
By far the most controversial discovery of the year, I’ve written about the EMDrive in detail here so I won’t go on. But there’s a possibility Harold White of the Eagleworks lab may have uncovered a new form of locomotion for spacecraft, as well as maybe settling the longest-standing debate in quantum mechanics. That’s if his research holds up to scrutiny of course.
Evolutionary Speciation Observed (November 28th)
One of the cornerstones of Darwin’s evolutionary theory is that a species can, over a long period of time, split into two forms of creature - a process called ‘speciation’. Unfortunately it usually takes such a long time that it’s not something we can observe (giving anti-evolutionists a pretty reasonable objection). However, thanks to Justin Meyer’s team at San Diego University, the process of speciation was finally observed for the first time in an extremely fast-breeding species of virus. It’s as if Darwin was onto something.
Preserved Dinosaur Feathers (December 19th)
Lida Xing from the China University of GeoSciences announced the discovery of a perfectly preserved dino-feather. Just like in Jurassic Park, a bit of fossilised tree-sap from 99-million years ago was unearthed containing a fully preserved feather. And now, I highly recommend you listen to the epic Jurassic Park theme by John Williams. In fact, as you listen, go back through my list and remember how wonderful we truly are.
In 2016 we carried out thought transplants, created cyborgs, discovered life after death, cured paralysis and invented new ways of improving people’s lives and helping people bring healthy babies into the world. Don’t feel down-hearted when you look around, my fellow humans. We’ve done a lot of great things, and we will continue to do so because we are the human race and we invented Science. Take it away John...
We are not alone
In my last blog I calculated that the chance of life on other planets is very promising. But is that something to get excited about? I mean, has anyone seen Independence Day? In that movie an advanced race called "the harvesters" (there's your first clue) discover our planet and attack. Their technology is so sophisticated that the entire human race is almost wiped out in 24 hours. We're only able to defeat them because we have Jeff Goldblum, American Flags and Apple product placement.
It's a valid point. Let's say there are thousands of civilizations out there. It's unlikely we'd be the most advanced one. There's a chance of course, someone has to be, but it's more probable other races would be ahead of us. And this could be a threat.
Imagine if the 21st century decided to declare war on the early 20th. That would be us with nuclear weapons, airplanes, radar, submarines, drones, chemical warfare, guided missiles and satellites against the bayonets and horses of the first world war. It would be a massacre (just like the real first world war).
The technology at our fingertips is unprecedented. Even within my lifetime I've found it hard to believe how quickly things have developed. 20 years ago the concept of video-calls, ipads and mobile phones was the realm of sci-fi. I still find chess-playing computers a bit spooky, let alone thumb-print recognition on Samsungs and a freaking space station orbiting the planet.
An alien race, even a few decades ahead of us, would appear like Gods. If they decided to attack us, have no illusions; we wouldn't save the day thanks to plucky human determination. We'd be trampled.
Many have even suggested that this is the most likely scenario. Look at how the conquistadors treated the native Americans or how the British treated the aboriginal peoples of Australia. The British "Empire" has a long history of landing in a place, enslaving/exterminating the locals and claiming the land simply because they could. Wouldn't there be a risk of aliens doing that to us?
As it happens, I don't think we have anything to fear. The idea of aliens declaring war on us is a bit far-fetched. Any species arising on another planet will face the same trials and challenges we do on Earth, which means we can look at how life evolves here to get an idea of how it would evolve there. And there are four basic truths which suggest we don't need to be afraid.
Reason 1: An advanced species won't be evil
People are fond of bleating on about how awful humanity is. We're the only species to invent war, the only species to invent racial genocide, the only species to knowingly pollute the environment etc. Give me a break. The tune is getting cliched and the lyrics are fundamentally wrong. Humans aren't the most evil species. We're just the most powerful.
Chimpanzees are known to form raiding parties and launch attacks on the next tribe over, killing the young and claiming the females for breeding. That's war, genocide and slavery. Orca whales have been observed catching sea-lions and tossing them back to freedom for a few seconds before capturing and repeating the process. That's torture for no reason other than sadism.
Point is, other species show exactly the same streaks of cruelty, greed, pre-meditated aggression and selfishness we do. Humans have not invented the concept of violence, we just use better tech. But I'll tell you something which does set us apart. We're the species who donates aid to countries hit by natural disasters. We're the species who volunteers to build schools in disadvantaged communities. We're the species who invented the concept of "peace-talks". Think about that. We're the species that goes out of its way to avoid conflict.
The vast majority of people, when they learn about slavery, the inquisition, the holocaust, the crusades, respond in the same way: horror. We're capable of awful acts but we're also capable of feeling shame. We can look back at dreadful things we've done and recognise them as such.
Thanks to the internet, today's youth are so much more savvy than I ever was. They've got friends all over the world, followers in different cultural pockets and they read blogs with views different to their own. Today's generation are more globally aware and more atuned to the big issues than any in history. And this is important. As a species advances technologically so does its quality of education and so, therefore, does its culture.
Yes, there are still yobbos who spew conspiracy claptrap on twitter and yes, there are still people who work in advertising. I'm not saying we're a perfect species, but I am saying "look how far we've come!"
I can't pretend we're living in a utopia of course. I know there's fighting going on. You can probably name several countries without even trying. But do you know why your brain can do that? Because the countries at war stand out as the anomalies.
The human brain is very good at noticing things which don't fit a pattern, but we're not so good at putting that information in context. For example, there are currently around 16 countries locked in major wars. There are 196 countries in the world. Do the math. That's 92% of countries in the world currently NOT at war.
Don't get me wrong, I'm not trying to downplay the fighting currently taking place. But remember the job of the news is to focus on stories which stand out. News coverage highlights the extremes - and rightly so. We should all be aware of wars taking place. But the flip-side is that watching the news can give us a warped picture of what the world is actually like. Because you never hear about the peaceful countries your brain fuzzes them away. And so you start thinking of the world as a war-torn place. It's not. It's pretty peaceful.
When two countries disagree, the most you usually get is "tensions rise" or "heated political crisis". All-out war is something we usually try to avoid because we've been there and it's not nice. We're so lucky to live in these times and we ought to remember that.
And the further you wind back, the more sophisticated you realise we've become. Today we have institutions like Guantanamo bay and they get media attention because of how medieval they are. When we look at prisoners being tortured and brutalised, we are shocked that it's happening "in this day and age" because we know, deep down, that things are better today than they have ever been. We have an unspoken understanding that these violent acts are wrong because, as time passes, the human race is slowly getting over its desperate need to kill.
Slavery has been abolished in the Western world. Women have the right to vote and get educated. We look after the elderly rather than leaving them to die in workhouses. There are child labour laws. The Court of Human Rights exists, as does the Geneva Convention. We have healthcare, affordable electricity, heating and clean water for many. Point is: the more advanced a civilization, the more civilized its members.
An alien species may have a similar violent past to us but they will also have developed education, technology and Scientific understanding. Aliens might be cautious of humans, but I don't think they would attack and brutalise us...because we wouldn't do that to them.
If you've seen Avatar you'll remember the film has lots of gung-ho maniacs hell-bent on forcing the aliens out of their territory and I accept this may happen (I don't know which side of the film's analogy represents us) but there would also be people like Sigourney Weaver's character - people who want to learn and build bridges. There would be people like Jake Sully (the protagonist) who go in with a militant attitude, but who are willing to learn and change. An advanced race is an educated one and an educated race is, by its nature, peaceful.
Reason 2: An aggressive species doesn't last
You hear people talk about nature being red in tooth and claw and sometimes you hear them talk about how animals and plants live in harmony with nature. You want to grab them by the scruff and shout "make your mind up!" The reason people have a confused picture of nature is because nature isn't simple. There is no such thing as an aggressive or peaceful species, the reality is that every species has the capacity for both.
A crocodile who attacks a gazelle is rewarded - it gets a meal. But a crocodile who doesn't chomp down on a plover bird is also rewarded - it gets its teeth cleaned. A planet has limited resources so every species has to learn coping strategies. And being constantly aggressive isn't a good one.
Take the xenethsis immanis tarantula. It has learned to keep tree-frogs as pets - the frogs then consume insects who attack the spider's eggs. As a result the frogs get a meal and the spiders don't lose any young. If the spider had been more aggressive it would have eaten the frog and lost out.
Being aggressive also makes you more vulnerable to retaliation. If you fight everyone, you get attacked all the time and eventually you'll meet someone who can break you. Take the footage of the lion attacking a giraffe we all saw on Planet Earth 2...the lion got battered. The "peaceful" creature actually did more damage to the "violent" one. Because the truth is that giraffes aren't peaceful and lions aren't violent. They are both a mixture.
Any species learns this lesson by accident/instinct/inheritance etc. but a self-aware species like humanity has learned this lesson as an actual fact: don't go around attacking everything because you miss out on stuff. An alien race will have discovered the same optimal strategy. They will know that attacking a less-developed species might not be a sensible default position. Again, they might be ready to blast us out of the sky if we pose a threat but an alien species is (like us) going to have the capacity for cooperation as well as aggression.
By contrast, a species who attacks everything will ultimately become extinguished. Either due to in-fighting or picking a fight with an equally capable enemy. Only a species capable of taking a step back and not pushing the button is going to survive. Alien races stumbling across Earth will have faced their own Cuban-Missile-Crisis, their own World Wars and they will have survived just as we have. Only a species capable of holding back on aggression will be around long enough to make contact with others.
Reason 3: Empathy
This is a small point, but a crucial one. A species that has the ability to learn is a species who can emulate creatures around them. This ability to "put yourself in another's shoes" gives rise to the most wonderful quirk of mental evolution: empathy.
Take the recent public outcry regarding the turtles on Planet Earth 2 (seriously, if you haven't watched that show, I'm ordering you to, it will make you a better person). We have no reason to feel empathy for turtles and yet we do. Because we're an intellilgent species we're capable of mentally transposing ourselves into the minds of other creatures. We can recognise a common "desire to live" and we can respect it.
Some people are psychopaths, missing the capacity for empathy - these people often do well in business or marketing (for obvious reasons) - but most of us, when we see suffering, feel bad. Most of us, if handed a gun and told to shoot a puppy in the face, couldn't do it. I'm not even a dog person and I wouldn't pull the trigger. If the dog were attacking someone I cared about that might be a different story, but shooting a weaker creature for no reason just isn't something I feel any reason to do.
An advanced species is likely to be the same. They wouldn't attack us because they would empathise, even a little. They would recognise us as fellow travellers in this vast Universe, flawed just like everyone else. They would remember a time when they too were lonely, confined to their own world and they would take pity. They would see a commonality and would hesitate about pressing "fire" on the plasma cannon. Same way we would refuse to shoot a defenceless puppy.
Reason 4: There is no need to attack Earth
The first place a fledgling species is going to get its energy from will be the planet itself. Humans do this by extracting old bits of plant and fish from the ground, but it's no secret we can't keep doing it forever. The reason is simple: the population is increasing and the fuel is decreasing. Sooner or later we'll run out and we'll have to look elsewhere for our demands to be met. And any advanced species will face the same puzzle: adapt or die.
Fortunately, the Universe provides every planet with a quick-fix. We all come fully equipped with a burning Sun right on our doorstep. The Sun is a nuclear reactor and its output contains enough energy to power thousands of Earths for billions of years...for free. All we have to do is use it. We wouldn't even have to go to war with anyone. Nobody gets exploited, we just switch on our solar panels and capture the light. Arguing over fossil-fuels while the Sun floats nearby is like sitting beside a bonfire and arguing over who owns the biggest mathstick. It's illogical.
Thing is, we have the technology and know-how to power the Earth from the Sun right now, we're just dragging our feet because it involves change. One thing which is definitely true of humans is that we don't like to modify our behaviour unless forced. We don't adapt until the very last minute and technically, right now, there isn't a pressing need to switch to a solar economy. There will be soon, and I'm hoping we've got the sense to actually do so, but right now we're getting away with being sluggish.
Every other species will face the same problems of course: switch to a renewable energy source or become extinct. So, it stands to reason that an advanced alien species will be a sustainable one. The only way to become a space-faring species in the first place is to switch to harvesting solar energy. A species which can't be bothered to make this change won't last.
And this is the ultimate reason we'd be safe...if an alien species is technologically advanced enough to provide for itself and go on adventures around the Universe, why would they possibly want to attack the Earth? We don't have anything an alien species would want! We've got water, various minerals, a molten core and a few other sundries, but (as I explained in the earlier blog) those things are found everywhere. The Earth is not even remotely unique or special.
Flying across a galaxy takes considerable effort. There is no reason to do that unless you're going to get something valuable. An alien race declaring war on us would be like us declaring war on penguins. They live far away, in a place we're not interested in, which takes effort to get to, and they don't have anything we need. They've got ice, water, rocks and a bit of algae but we can get those things at home with minimal effort. Why go to all that trouble?
Imagine if Trump decided to gather the united forces of the U.S. military to march on Antarctica and declare war on penguins. People would just laugh...I hope. Aliens would feel much the same about Earth. Interested maybe, but certainly not envious or threatened. So that's us - the Universe's penguins. And penguins are never dangerous.
The Earth from above
Once again, I think the Sc-fi franchise which best captured the future of alien contact was Star Trek. In that show we go touring the galaxy "to seek out new life and new civilizations". Our whole reason for exploring isn't for warfare or profit, it's to learn. Sometimes there are conflicts, even battles. But Star Trek depicts a galaxy full of races at different stages, trying to make their way in the Universe. Ultimately the goal of every living thing is just to get by. We will learn to cooperate. We will live long and prosper.
Dalek: Forbidden planet
Independence Day: srcdn
Scrappy: See earlier blog
The last few weeks I haven’t had a chance to write anything on the website, answer any of the questions or make a youtube video. The reason is because every year the Institute of Physics gets me to do a Christmas lecture on “big” Science topics (action shot from this year's event pictured above). It’s great fun, but most of my recent spare time has been spent researching, planning and organising that. But now I’m done for another year I can continue writing, so I thought I’d do a couple of pieces summarising the talk for those who weren’t there. Enjoy…
The man who invented Star Wars
The first person to suggest the idea of alien life (and therefore a huge amount of Science fiction) was Giordarno Bruno in the 16th Century. He reasoning was that the Universe is so vast, it's ridiculous to suggest our planet is the only one with life. Unfortunately, this didn’t go over too well with the Roman Catholic church because it presents a few sticky issues for crucifixion theology.
For example, in Romans 6:10 and Hebrews 7:27 we are told Jesus’ death happened once and “for all”. If there are aliens on other worlds we have to wonder: are they included in the “all”? If not, God doesn’t value and forgive every conscious being, if they are included, then how do they learn the Christian message? Jesus only dies once, so he can’t visit lots of alien worlds and preach to every being out there. These are fascinating questions, but they were uncomfortable in the 1590s.
So, naturally, the church had strong words with Bruno. Those words were: we’re going to burn you alive. Giordarno Bruno was, in a sense, the first martyr for Science because he was put to death for his commitment to astronomy. Today it’s perfectly legal to talk about the possibility of aliens, so let’s do that.
What is life?
Defining life is tricky. In the Star Trek episode The Tholian Web, the enterprise crew meet beings made entirely of crystal. In the episode Charlie X, they meet creatures who exist as disembodied faces. They meet sentient clouds of light in Metamorphosis and so on. Life is such a varied thing on Earth, how can we possibly define it for the rest of the Universe?
Perhaps there could be creatures made of plasma living in the hearts of stars. Perhaps there are beings living in extra dimensions of spacetime who inhabit the cores of black holes. Perhaps we’re being visited by alien life all the time but it’s so different we don’t even recognise it.
If we say “life comes in an infinite variety of forms” then by definition, the Universe is full of creatures. We could argue that stars are living, as are nebulae and pulsars. That answer isn’t useful. If we want to discuss the question practically we need to limit our scope.
For my money, NASA has come up with the best definition of life so far: “a self-sustaining chemical system capable of Darwinian evolution”. That’s a mouthful but it simplifies to: “very, very complicated chemistry.”
On Earth and other planets, we notice there are lots of simple chemical substances lying around. Crystals, rocks, gases, liquids etc. In fact, there’s more of these simple chemicals to be found than complex ones. Most of planet Earth is made up of things like molten iron, nickel, rocks and discarded Coldplay albums. Interesting chemically, but too structured to be considered "living".
Thing is, simple chemical substances are very regular. Rows and columns of atoms stack up to form crystals, metals and rocks, or they float about freely to make liquids and gases. Simple structures aren’t capable of doing anything interesting because they’re so organised. Chaotic structures like gases have the opposite problem – things float around so easily it becomes a chemical free-for all, nothing is stable enough to interact and evolve. So we have to rule out simple Chemistry and simple chemical reactions…they aren’t living in a meaningful sense.
All life on Earth (over 1.7 million different species discovered so far) is complicated. Atoms arrange in chains, spirals, sheets, clumps and clouds. Molecules are specifically shaped to fit through certain gaps and not others. Particles carry each other from place to place like nanoscopic machines, structures are pulled apart, rearranged and even self-constructed. The Chemistry of life is like an insane factory and this is what we need…intricate, complicated and varied chemical reactions.
Chemistry is a bit like Lego. Atoms and molecules come in lots of different shapes and sizes, some more complex than others. Suppose you had one of those simple pieces which was just a single bump and hole. If your planet is supplied with these pieces only, all we get are chains varying in length. There is nothing more complicated or interesting possible.
Well, most atoms are like that. The majority are shaped to accommodate one or two bonds and that’s it. If all your planet has to play with are simple atoms, life isn’t going to arrange itself into existence. All you can hope for are crystals, rocks, gases and liquids.
Some atoms, on the other hand, are capable of forming several bonds. Carbon and Silicon can form four, Phosphorus can form five and some of the metals go even higher under the right conditions. Out of all these multiple-bond atoms Carbon is the smallest, making its bonds the tightest and strongest. This means Carbon atoms are really the most versatile. Although it has been suggested that life could arise from Silicon.
You do need lots of other elements besides carbon of course; Carbon atoms on their own tend to form simple crystal structures but if you start throwing in other elements, you start creating complexity. There’s all sorts of analogies for this, here are two I’ve thought up.
When you’re making a soup, Carbon is like the water. On its own, pretty boring, but if you chuck in bits of vegetable, spices, stock etc. (other elements) you get something much more interesting. Or, if you prefer a more Christmassy analogy, Carbon atoms are like the branches of a Christmas tree and the other elements are the decorations. On their own, nothing happens, but put them together and pow!
One of the really exciting things we’ve discovered in recent years is that the chemicals found on Earth are not unique. In fact, the elements needed to form complex structures are found throughout the galaxy. The reason we know this is that different elements give off specific frequencies of light. If you look with the right kind of telescope you can analyse the light signatures of different parts of space and find out what chemicals they’ve got. And it turns out that Earth is not rare at all.
Actually, the chemical building blocks used for Earth life are abundant wherever we look. Not only that, but the more advanced chemical structures (things like amino acids, which the elements combine to form) are also found elsewhere. The whole galaxy has the ingredients for life readily available.
If your complex chemical building blocks are all packed together in solid form, life doesn’t arise because they can’t move around and exchange information. Likewise, if your building blocks are floating freely and not coming into contact for any length of time, reactions are rare. Chemical processes, particularly complicated ones, really need to be sitting in a liquid.
Ideally this liquid should be unreactive so it doesn’t interfere with the chemicals floating in it, but it should be good at dissolving the ingredients. There are only a handful of such liquids known, the most common being water. We don’t know for definite that life needs liquid water but it’s a good candidate. Every time we find water on Earth, we find life, so it’s definitely favourable. Life might be able to form in other liquids like ammonia or hydrogen sulphide, but seeing as all those chemicals are pretty common to the Universe it’s immaterial which one we pick.
Most planets probably have the right starting point for life but we need to address the other crucial factor: temperature. If your planet is too close to the sun it orbits, the liquids boil away and all those complicated chemicals burn up. If your planet is too far in the other direction things get cold. The liquids freeze solid and chemicals don’t have enough energy to react successfully.
In order for a planet to have liquids on its surface and keep the chemical ingredients from breaking apart, it has to be just the right distance from its star, orbiting in what’s called the Circumstellar Habitable Zone or…Goldilocks zone. Not too hot, not too cold. In our solar system, Earth is the only planet in the Goldilocks zone for definite (Mars might be, there’s a debate over how wide a goldilocks zone should be). And lo and behold, life has arisen.
To be clear, we don’t know how life actually got started and what else might be necessary (although the field of abiogenesis is yielding some intriguing clues). Perhaps you need a planet with a moon to set up stable tides for rock-pool formation, perhaps you need a magnetic field to protect you from cosmic rays, perhaps you don’t need either and life just “finds a way”. What we know with confidence is that life needs the right ingredients…which are found everywhere…and the right temperature to put them together.
Crunching the Numbers
Now we’re at the stage where we can do a back-of-the-envelope calculation on how likely life might be in our galaxy. First, take the number of Suns. It’s estimated to be between 200 and 400 billion. Let’s take the lower number to please the cynics. How many of those 200 billion Suns are like ours?
This is importanht because some Suns are less genteel than ours (particularly those near the core of the galaxy) and they’re so “bright” they destroy complex chemicals. But, fortunately, those evil Suns make up about a quarter of the galactic composition. Three quarters of the Suns in our galaxy are exactly like ours. So that’s 150 billion Suns. Right, how many Suns have planets going round them?
Well, the answer seems to be all of them. Planets always tend to form as a byproduct of star-formation (the dust which doesn’t get pulled into the Sun ends up orbiting in a disk until it starts clumping together to form planets). In fact, we’ve discovered over 3544 planets orbiting other suns – what are called exoplanets. So if we want to be realistic, we’re probably talking about 150 billion planets as well. Let’s be pessimistic though and assume only 90% of all suns have planets. Let’s also assume only one planet per Sun. That gives us 135 billion planets in our galaxy…minimum.
And how many of them are in Goldilocks zones? Well, of the 3544 we’ve discovered, about 7 of them are Goldilocks (that’s being really stingy with how narrow we make our goldilocks zone though). So that gives us 0.3% of planets forming inside Goldilocks zones. And what is 0.3% of 135 billion? 405 million.
There you have it. By limiting ourselves to carbon-chemical-based lifeforms only, the minimum amount of Suns, planets etc. we end up estimating that our galaxy should contain around 405 million possible worlds. Even if life is a tricky process to get going, those numbers are good. Life could be a 1 in a million shot and we’d still get 405 civilizations arising. And that’s just in our galaxy – which is but one of millions of billions.
Giordarno Bruno was right. It is statistically bizarre to suggest Earth is the only planet with life. There's a possibility it might be, we don't know for definite yet, but the odds are very much in our favour. So, is there anybody out there? According to Science the answer is probably!
George Lucas: amazon
Ian Malcolm: carboncostume
The story being reported all over the world is that Harold White of NASA has just built a machine which breaks the laws of Physics. It's called the EMDrive and it's making serious waves...electromagnetic waves! badoom cha! Let's take a look.
Every vehicle ever constructed works on the same principle. Push something backward and you get pushed forwards. When you're pedalling a bicycle the wheel pushes on the Earth and the Earth pushes on the wheel. The Earth is much heavier of course, so it hardly changes what it's doing. The wheel on the other hand is so light that the same force applied will produce a much greater effect, propelling the wheel forwards and tadaa - motion!
Any vehicle which has an engine works exactly the same way, only it uses trillions and trillions of particles of reacting, burning fuel. All engines work by ejecting the fuel backwards, which pushes the vehicle forwards. It works like this:
small mass (fuel) x large acceleration = large mass (vehicle) x small acceleration
It's called Newton's third law and it's fundamental to our understanding of modern engineering. Everything (ever) obeys this law. There's another similar law called the "conservation of momentum principle" which also holds true. The c.o.m.p. says that mass x velocity before a collision (before the fuel collides with the interior of the car) is equal to the mass x velocity afterward. If you add up all the masses and velocities of every particle of fuel and every particle in the vehicle, before and after the vehicle moves, they cancel out perfectly. The universe keeps momentum (mass x velocity) the same everywhere. It is conserved.
Our entire understanding of engineering, mechanics and even movement itself relies on these two principles being true. Every experiment confirms them and we have never had any reason to doubt. That is, until now...
What is the EMDrive?
The EMDrive is a prototype engine which propels an object by exploiting the interaction between EM (Electromagnetic) waves and matter.
How does it work?
The EMDrive is surprisingly simple. You take beams of low-energy light and bounce them around a metal cone. These low-energy beams are called microwaves - the same invisible beams of light which bounce around inside your microwave oven.
Microwaves don't have mass but they interact with massive objects and cause them to vibrate (that's how a microwave oven works, it vibrates particles in your food, heating them up). The EMDrive uses these microwaves to vibrate the metal cone and by carefully controlling the angle and concentration of the beams, the cone starts vibrating forwards.
The Washing Machine Analogy
Imagine a washing machine vibrating on the floor of your kitchen. It ends up slowly creeping forward because it's pushing against the ground. Now imagine doing that in empty space, where there's no ground beneath it, just a free-floating washing machine. If you turned it on and it started creeping forward you'd have to ask the question...what is it pushing against??? This is essentially where the Scientific community is at right now.
How good is the thruster, if it works?
Pretty good. If the early estimates of White's team are correct, this engine would have the ability to transport us to Mars in a matter of weeks, rather than years. This could genuinely be the device which opens up the solar-system! Travelling to new planets would become equivalent to early sailors in the 19th Century travelling across the Atlantic. It could usher in a new era of space flight and exploration and, as I've pointed out in one of my videos, funding the space program is a good idea for humanity.
What's the Catch?
Well, remember earlier that we established the conservation of momentum principle and Newton's third law? Well the EMDrive pushes the object forward without pushing anything backward. There is no fuel being ejected from the back of the thruster, meaning the cone appears to start moving of its own volition. The equation above has 0 on the left hand side (no force on the fuel), yet the force on the thruster is there. This seems to be impossible. It utterly changes the laws of Physics and as a very wise engineer once said...
So what's going on?
Nobody has a freaking clue. White's team don't even have an explanation for how it works. The research paper details the basic design, the experiments they've conducted and the results they've gotten. But they provide no clear mechanism about how it actually works. So the honest answer to "how do microwaves bouncing around a metal cone generate thrust?" is that we don't know. All we know is that it shouldn't happen...assuming our laws of Physics are correct.
Are the Laws of Physics wrong?
Well, possibly. One of the most important things about Science is that NO LAW IS ABOVE QUESTION. Every theory, even tried-and-tested ones, are still open to doubt. Nothing is known with 100% certainty in Science and we like it that way. If we aren't open to the possibility of correcting ourselves, we never learn anything new.
But Newton's Third Law normally works, right?
The third law obviously isn't nonsense because we've tested it repeatedly for centuries and built our entire industrial revolution on it. If it's an approximation, it's a very good one. But, this has happened to Newton before.
In 1687 he published his gravitational law (F = Gma*mb/r^2) which works well on Earth but, it's not quite perfect. The orbit of Mercury deviates from the law slightly because it's close to the Sun and gravity is significantly different there. It took Albert Einstein to work out a more detailed model of gravity in 1915 (General Relativity) which shows that Newton's approach is a "works in most cases" example. It's possible Newton's third law might be due for a similar overhaul.
So, was Newton really all he was cracked up to be?
Yes he was.
What's the alternative to Newton's third law?
We have no idea. This research is five days old (at the time of writing). White's team, in their research paper, put forwad a tentative explanation for what they think might be happening though. They suggest the EMDrive might be pushing against something which doesn't have mass in the normal sense. They propose it might be thrusting against something called "the energy density of the quantum vacuum".
The idea is that empty space isn't really empty; it has a background energy-value to it. Since energy and mass can be treated equivalently (E = mc^2) perhaps the energy of the background can be treated like something with mass. Something we can do work on.
If this is true, it might also solve one of the greatest riddles in modern Physics: the interpretation of the quantum mechanical wavefunction. I don't want to get swamped, but it's another mystery of Physics which has stood for close to 100 years. White's research might be one of the first bits of evidence which shows that "the Bohmian pilot wave interpretation" is true (here's good ol' Wikipedia explaining it). If White's research is validated, he may soon join the illustrious ranks of Richard Feynman, Erwin Schrodinger and Bob Dylan...Sweden beckons?
Who is publishing the research?
Whenever a Scientific claim is made (especially a big one) you have to look at who the people are behind it. Granted, any claim is worth listening to and you don't chuck out a hypothesis because you don't like the person, but if the research is being published by someone who's known for perpetrating engineering hoaxes for example, you might be a little more skeptical.
This research comes straight from NASA's Eagleworks lab, headed by Harold White. Harold White is also the guy who wants to test the Alcubierre "faster-than-light" engine, which is a story for another time. The point is, the Eagleworks lab is a team of talented engineers looking to find new ways of propelling spacecraft. They aren't a bunch of yahoos working out of their grandmother's basement. These guys are the real deal. It's proper research done by meticulous Scientists.
How good is their research?
This is the crucial question which now needs to be answered. The paper they've published has been checked by other physicists and passes the preliminary "hmmm, seems potentially legit" test (called peer-review). Now, like any good Scientist, the most important step is to publish and let the world a) look for mistakes and b) try to replicate their findings.
What we're currently witnessing is Science's strongest weapon: get other people to try and disprove/confirm your idea. It's no good saying you've discovered something if you don't let other people grill you. But now their research is freely available for anyone in the world to look at, and believe me, they will.
If you're interested: here it is
Seriously, give it a read! A lot of cutting edge Physics can be hard to keep up with if you're not fully mathematically literate and don't know all the jargon and notation. But this paper is actually a pretty straightforward read.
I've read it through a couple of times myself but I'm not an engineer. I'm a high-school Physics teacher and this isn't my area of expertise. I'm not qualified to make a judgement on whether the research holds up, but thousands of superior Physicsts all over the world, from undergraduates to tenured professors, will be casting their eye over the White paper and scrutinising its every detail in the coming months. If there's a mistake, even a subtle one, someone will find it.
White's paper does outline 9 potential sources of error they could have made (a good Scientist openly points to flaws in their own argument) but the question is whether these errors are significant or minor. Sometimes a headline-making news-story turns out to be a mistake (like the faster-than-light-neutrinos thing five years ago) so this one may be pulled apart as well. In fact, to suggest a change to Newton immediately puts you on shaky ground...but the only authority in Science is evidence and if your evidence contradicts Newton, so much for Newton.
So, has NASA just built an impossible machine?
Well, if they really have built it, it's evidently not impossible. What we really want to know is, do we have to change the laws of Physics? I see three logical outcomes:
1) They've made a mistake in their research.
2) Newton's third law needs to be modified.
3) Newton's third law is still correct, but there's new Physics at work we've never dreamed of
We have to remain skeptical with any claim like this. At the moment, this is a single research paper claiming something seriously weird. Whether their evidence is extraordinary remains to be seen. The line we need to be taking is one of healthy, if optimistic, skepticism. We don't know if NASA has just built a working EMDrive...but we are definitely, most definitely, allowed to get excited!
EMDrive - from the original White paper
Like many people in the world, I woke up a few days ago and was interested to learn that Donald J. Trump is the new President elect of the U.S.A.................Surprise!
On January 21st Trump will be sworn in as commander-in-chief to one of the most powerful nations in the world, along with a cabinet, house and senate of other Republicans, giving him more power than a president has had for 90 years. Many people are a little worried about this.
A candidate like Trump has never been given this kind of opportunity. Simply put: we don't know what he's going to be like. He's a man with minimal political experience and, in the run-up to the election, has been accused of racism, mysoginy, islamophobia, homophobia, he's made unusually lewd remarks and some rather wild accusations.
But maybe, maybe, maybe, this is all just confident speechifying. Maybe he doesn't mean a lot of the things he's said - after all, we all say foolish things when we're under pressure and there are thousands of people cheering us on. Maybe he's not what people are accusing him of.
As a teacher it's normally considered bad form to discuss my political views. I understand the reason. However, I also have a duty to speak out against bigotry and ignorance - both as an educator and a human being. History doesn't look kindly on those who stand by and say nothing, so I honestly feel my conscience is a lot clearer if I speak publicly about my concerns. So here goes.
I'll be as diplomatic as possible because Trump has been fairly elected by democratic vote and we have to respect America's decision. If you reading this are a Trump supporter then congratulations on your victory! I'm hoping you'll be willing to let an outsider raise some concerns and criticisms. After all, what's politics without debate?
Donald Trump's upcoming presidency does worry me. I don't think it's going to be the end of the world though. There's been a lot of hysteria about what's going to happen but we should at least give him a chance before we start labelling him the anti-christ. Nobody thought Ben Affleck was going to be good as Batman, and that turned out fine. Perhaps Trump's unorthodox approach to...everything...will do wonders for the global economy. I'm no financier so I'm not qualified to comment.
Maybe Trump's foreign policy and views on immigration will lead to an enlightened age of racial tolerance and harmony somehow. We have sadly seen an increase in race attacks in the USA over the last few days, but we can hope they will die down. Again, I'm not a sociologist so anything I say on this matter will be nothing more than opinion.
What I am qualified to talk about is Trump's position on Science, public awareness of Science and Science education. And this is where I hear alarm bells.
The Trinity of Science Denialism
President Trump, his vice president Mike Pence, and the proposed secretary for education Ben Carson, have all made some troubling comments regarding Science. It all amounts to the same problem however: they deny many of the importance facts Scientists have discovered. Trump, most spectacularly, has said the following:
He's also explained that he thinks vaccines cause autism:
Mike Pence, the new second-in-command explained in the 107th Congress meeting (second session, July 11 2002) that he did not accept evolution and that it was just "a theory" which should be taught in schools alongside other "theories".
Then we have Ben Carson who may soon be in charge of America's education and therefore the Scientific understanding. Carson denies evolution, saying that Darwin was encouraged to come up with the idea because he was encouraged by Satan. He also describes the Big Bang Theory as a "fairytale" about an "explosion" which "contradicts the second law of thermodynamics".
Denying the existence of things like climate change, evolution and the big bang is to put yourself firmly in opposition to the Scientific community. So it's a problem that the three people who have the most power over American Science don't seem to accept its claims.
But isn't it just their opinion?
That's a Sarcastic response
I've said it before, I'll say it again, and I'll keep saying it until the day I die: you are entitled to your opinion but you can't have opinions about nature. It makes no sense. It's like having an opinion on the existence of pigeons. You can have one but it's ridiculous. The natural world - reality in other words - is not the realm of opinion.
Nature makes the decisions about what's going on, not us. If you want to find out what the world is like you can't chuck out the bits which conflict with your personal beliefs. Either you abandon your personal beliefs or modify them to fit the facts. You have to accept nature in all her ugliness as well as her beauty.
Yes, fair enough, you can technically believe whatever you want in the privacy of your own home. If you want to sit there denying the existence of evolution, the big bang, climate change and the number 19, then be my guest, I can't stop you. But if you're in a position of power you have to leave your personal beliefs at home. You have the right to disagree with reality but you have a responsibility not to.
Come on Trump, We're counting on you to do better!
Trump's climate-change objection is not that rare. It's a confusion between local weather conditions and global climate. If the USA is having a big freeze, this doesn't disprove climate change. the comedian Stephen Colbert compared it to saying there's no such thing as world hunger because many Americans have food.
Trump doesn't understand the distinction between weather (what's happening in one place during one period) and climate (the overall pattern of weather phenomena for the Earth over many periods). It's also worrying that his source is NBC News, rather than research journals.
Thing is, this particular misunderstanding of weather and climate is common (although the Chinese element is genuinely a mystery to me). But the president can't afford to make common-ignorance mistakes like that.
The president has a responsibility to either understand the issues in their full complexity or hire advisors who will. He's falling for a common misconception which would be forgivable if he were still just a businessman/celebrity, but now he's the president elect, he can't afford to do that any more. He needs to step up his game. Fast.
97% of Scientists are in agreement that climate change is taking place as a result of human action. If Trump wants to align himself with the 3% of doubters he'd better have seriously good arguments rather than just a report he saw on NBC News.
Already, Trump has talked about pulling funding from clean energy projects and investing in oil pipelines and fracking. He claims this will be good for America's economy. And you know what? He's probably right. He's even said he's "going to be greedy for America." Which of course sounds nice if you're American. But climage change isn't an American problem.
To quote Isaac Asimov "We are talking about something that affects the entire Earth, these are problems that transcend nations". Climate change is bigger than just America and if Trump decides to steer America selfishly he may lead them to prosperity at the expense of the entire planet. A few decades of wealth in exchange for centuries of misery. I just think he needs to take more care with his approach rather than making bold statements which lack subtlety.
Same goes for the vaccines-autism thing. His tweet seems to be implying that a) autism is unhealthy, b) young children suddenly not feeling good = autism and c) there's a causal link between vaccines and autism.
If you're curious, here's the actual evidence for the vaccines-autism link: In February 1998, a doctor named Andrew Wakefield published a report in The Lancet magazine in which the parents of twelve children exhibiting autistic-like behaviour were interviewed. Eight of the twelve parents said they thought the MMR vaccine was the cause. That's it. That's the sum total of evidence. The opinions of eight sets of parents.
The media frenzy which followed has a lot to answer for but this evidence is so sketchy it's barely worthy of the name. Trump's statement that there are "many such cases" actually means eight. Now yes, autism diagnoses have increased in the last few decades (doctors are now more aware of the condition) but so has the number of oscars won by Meryl Streep...is there a causal link between autism diagnoses and Streep's acting success?
Trump's position is a potentially dangerous one. Think of the number of people who might forego a vaccination, putting their child at risk, because they believe it causes autism. And, let's just point something else out. Even if the MMR vaccine did cause autism (it doesn't) but even if it did (it really doesn't) why is that a bad thing? What's wrong with autistic people? And even if we decided that autism was a bad thing and that the MMR vaccine increased its chances...would you rather have your child grow up autistic or die of Measles?
Again, Trump can say what he likes on his twitter feed, but now he's the president he needs to take more care. What he decides will affect millions of people and he can't afford to make sweeping statements that demonstrate a lack of understanding. I'm hopeful that Donald Trump is sensible enough to be prepared to change his mind in the face of evidence, and I really think if he looks into it (rather than just going with anecdotal evidence and hearsay) he'll come to change his mind. So come on Trump, get your Science in order, we're counting on you!
Pence and Carson
Pence's evolution denial is another forgivable mistake because he seems to not understand what a "theory" is. He's correct that evolution is a theory but a theory doesn't mean a guess, that's a hypothesis he's thinking of (something I recently covered in year 7 Science lessons).
A theory means an idea which has been confirmed repeatedly by evidence. That's why we call it the theory of evolution, rather than the hypothesis of evolution. Same with the theory of gravity. The theory of the round Earth. The theory of relativity. The theory of electricity. There is no such thing as "competing theories". There are competing hypotheses (guesses) but once the evidence is in only one of them becomes theory.
Evolution is the theory of Biology because it's the one which has been confirmed endlessly and repeatedly by conclusive evidence. I'm not sure what these other ideas he's talking about are, but they aren't evidenced so we shouldn't be teaching them as equal to evolution. Come on Pence, you need to understand what a theory is before you can talk about rejecting one!
Carson's comments are probably the most bizarre of the three (which is really saying something when you consider who the other two people are). Firstly, the big bang wasn't an explosion as he states - that's a grade-school misunderstanding and secondly it does not violate the second law of thermodynamics. The big bang theory (again, there's that theory word) actually validates the 2nd law. Besides, if there was a contradiction between the 2nd law and the big bang don't you think Scientists would have noticed? If there's one thing Science excels at it's chucking out ideas when better ones come along.
Again, Mr Carson, I don't have a problem with you misunderstanding the big bang or the 2nd law because they're complicated ideas...but you're about to be in charge of children's education. You have to be careful calling something you don't know much about "a fairytale".
For instance, I'm aware that Biologists often refer to a thing called mRNA and I don't fully understand what it does. But I don't call it a fairytale. If I want to find out about mRNA I do some research/experiments or I openly confess my ignorance (as I just did) before I go around making bold comments like "it's a fairytale". Again, believe what you want in private, but don't let it affect your political actions.
Politics and Science
In 2009, at the Policing and Crime Bill Committee (4th sitting, 29th January, Col.112 answer to Q195) the member of parliament Vernon Coaker said "you pick the evidence which, in the end, backs your argument". Argh! No! That's the Scientific process backwards! You don't start with an argument then look for evidence. You look for evidence, then build your argument based on it.
You can find evidence to support any weird and whacky claim you like (google "evidence for unicorns"). But that's not a good way to do things because Google only gives you what you want to see - it doesn't have a "disprove my search" function. Maybe it should.
Thing is, when working out the truth you need to start from ignorance then commit yourself to wherever Science leads you. This causes a problem if you're a politician however, because if Science takes you to a place your voters don't like, you have a crisis.
As a politician, you want to remain in office, which means you want to have the voters on your side. In order to have voters supporting you, you need to be popular. And here's the key. Politicians must align themselves with what is popular. Scientists must align themselves with what is true.
A lot of the time truth is popular, but oftentimes it is not. And that's when we get politicians either rejecting Science outright or deciding they don't agree with the evidence. Politicians often seem to think the best way to oppose something is to come up with a good counterargument. That's how it works in political debate - and that's fine. But a good, logical counterargument is worthless in Science. It's not about debate, it's about who has better evidence.
There's plenty of things in Science I wish weren't true. But there's no amount of clever arguments I can put forward which will undo what the Universe has stitched together. This is why Science and Politics often have a tense relationship. Scientists need political support (largely for funding reasons) and politicians recognise that Science is important for a healthy economy. But it's a rocky marriage. And, with Trump, Pence and Carson at the helm, we might be in for a divorce.
What's the Solution?
As I've said before, highlighting a problem is important, but it's even more important to talk about solutions. Otherwise I'm just whinging. So, do I think there are ways to fix this problem? Yes, I do absolutely. I have more hope than I have fear.
Having powerful people making decisions based on poor Science is going to be bad for the world. Worst case scenario is that climate change accelerates, lots of children end up with easily vaccinatable diseases and Scientific literacy in America plummets. How do we solve this problem? With two simple strategies.
1) Get educated
2) Educate others
In the 19th century having a good education was a priviledge. In the 20th century it was a right. Now, in the 21st century, it's a necessity. We need as many people to be well educated as we can manage. If the opposition is championing ignorance we need to fight back with knowledge.
Getting an education is no longer about giving yourself a better shot at life. It's about helping to save the world. If Trump makes bad decisions, we need to clear up the mess. If he makes good decisions, we need to be ready with the next step. If Trump doesn't know what decisions to make, we need to guide him. We need an army of people who know how Science works, who understand the subtleties of global politics and who understand ethics, finance, anthropology etc.
And then, when you know all that stuff, pass it on! Don't cache your knowledge like a nest egg. Educate people, spread the word and spread the Science. The world might be headed for a tough time so we need to take battle stations. This is the intellectual war we've been preparing for. Nixon had the war on drugs. Bush had the war on terror. Trump looks set for the war on Science. We need to fight back.
Let's make Science great again!
Head in sand: Philippatston
Meryl Streep: catchtwentydu
Ivana: the Star
Rise of the Discworld
You might wonder why, having talked about time-travel and gravitational waves, I'm dealing with something so basic and ancient as the shape of the Earth. Surely nobody believes the flat earth hypothesis in the 21st Century? Actually, quite the opposite. Flat-earthism is getting more popular every year, especially online.
As a few examples: the youtuber TigerDan925 (a flat-Earther) has over 26,000 loyal followers on his channel, the Flat Earth Society (along with many other organisations) has been rekindled under the leadership of Daniel Shenton and every day on Instagram I see hundreds of people passionately claiming that "globe-heads" are ignorant sheeple part of a global????? conspiracy. NASA photographs are all faked apparently, and the world's governments are prepetuating the round-Earth lie for all sorts of reasons, often to undermine the Christian Bible (which sometimes talks about the Earth being flat). How has this happened?
Woah, dude, they might be onto something!
If you've ever run across a flat-Earther you'll find they're not pitch-fork wielding yokels who cower at electricity. They're often well-spoken people who can defend their position with what sounds like good evidence. And that's part of the reason flat-eartherism appeals to many; their claims can be backed up with Scientific-sounding ideas.
A lot of the videos and articles by flat-Earthers contain nuggests of genuine Science. The FES (Flat Earth Society) website makes frequent reference to things like "Earth's axis symmetry" and "the Northern annulus" which sound like terms you'd hear in a legitemate astronomy class. Some of their arguments are so good in fact, you can't immediately spot why they're wrong.
Case in point: I'm a well-educated Scientist and I had a couple of moments researching this article where I went "hang on, how does a round Earth explain that?" Seriously, some of the flat-Earth arguments were so subtly wrong I didn't even notice where the mistake was at first!
I'm quite proud of that incidentally, not ashamed. I would be a bad Scientist if I decided "flat-Earthers are wrong" before hearing their evidence. As it turns out, their evidence is flawed in numerous ways, but the fact I had moments of "hmmm, that's interesting" is proof, I think, that I really was going in with an open-mind. So, to any flat-earthers reading this blog, I come in peace, waving a white flag.
But therein lurks the danger. I'm a well-trained Scientist and I couldn't immediately debunk some of their claims (not immediately anyway). Flat-Earth arguments are multiply confused it's true, but they do sound accurate so it's no surprise a lot of people can be seduced. To illustrate my point, here's a screenshot of some equations on the FES website:
When I first saw this I thought "hold on, that looks like Gauss' law and it proves that...ah, wait, no it doesn't." As it happens, those equations are being misused, but this doesn't look like the work of a lunatic, in fact the person who wrote this obviously has some mathematical training. Now, to be abundantly clear, every flat-Earth argument I've looked at crumbles under examination, but they often look fascinating, even to someone who knows what they're doing.
Most Flat-Earthers aren't Crazy or Stupid
One of the most interesting flat-Earth arguments I came across was actually on a German website and it said the following "das kabunkenfult ist der keine nicht; un spletze jarra die holten. Diese globe est eine kreiss mit der flatenzich." That's a very interesting sentence when you translate it into English.
Except it isn't, because it's not a real German sentence. That sentence is fake. Sure, there are a few genuine words which you probably recognised, but if you aren't fluent in German, you wouldn't know. It works the same with pseudoscience. It's so much like proper Science that if you're not an expert you can't distinguish what's real from what's not.
This is why a lot of sane, intellligent people end up believing things which are false. You hear technical words, see a few diagrams or equations, and if you're not careful, you can go along with it. Even the people perpetuating pseudoscience probably don't realise they're doing it.
If you're not confident on Science (actually even if you are) flat-Earth arguments can be persuasive because, and it shames me to admit this, they're taught better than real Science!
A Bad way to Learn
Most people are educated about the Earth being round by their parents before they even go to school. It's one of the first simple facts everybody learns: the Earth only looks flat because it's big and we're small. The problem is that most kids (myself included) are merely taught it and are never given evidence. Or, sometimes, the evidence given is wrong e.g. Columbus sailing around it, which can actually be explained on a flat-Earth.
We also don't spend much time proving the Earth is round in school. As a high school Science teacher I barely mention it. I just assume primary schools and parents have done the job, allowing me to move on to other stuff (although after researching this, I'm going to change that).
So, naturally, a lot of people grow up "knowing a fact" without the foundation for how we know it's true. When they come across clever-sounding flat-Earth arguments they find themselves questioning ther knowledge. Self-doubt is healthy and accepting facts dogmatically is not, so in a sense their decision is a sensible one.
Because many people aren't equipped to defend the round Earth, they reasonably abandon it when counter-arguments are suggested. Flat-Earth arguments look like they're based on reason (albeit sloppy) and the round-Earth is usually dictated as "thou shalt know this fact", making the flat-Earth seem more appealing. This is something we obviously need to fix.
Shut up, stupid!
I once overheard someone debating a flat-Earther and they said at one point, mostly out of frustration "Look, every Scientist believes the Earth is round, are you honestly going to disagree with millions of Scientists?" The flat-Earther responded, quite fairly, "yes".
I don't agree with the flat-Earther's cosmology but I do agree with their stance: you don't have to agree with something just because a clever person says it's true, that's NOT how Science does things.
Anyone can make mistakes and sometimes an entire Scientific community can get stuff wrong (look at phrenology). One of the reasons Science works is because we don't take somebody's word for it, we check it over and over. We're also open to new ideas and prepared to chuck out well-accepted theories because...
It's fine to disagree with someone in authority
It's fine to disagree with someone cleverer than you
It's fine to challenge the accepted view
It's fine to come up with your own hypothesis
Science isn't a democracy where we go with majority opinion. You're allowed to suggest any hypothesis provided you can a) test to see if it's right and b) are willing to back down if the evidence contradicts you.
Science is a dictatorship but the dictator isn't "the head of Science" (there is no such job, fortunately), the dictator is nature herself. If you want to know the truth you don't trust someone who makes the claim, you test it.
So, let's do that. How can we test that the Earth is round without relying on images from NASA, who would obviously be part of the conspiracy?
1. The Horizon Exists in the first place
If the Earth were flat you would be able to see across it, particularly at sea where there are no obstacles in the way. Yet we find our scope of vision comes to a limit after a few kilometers and using binoculars doesn't reveal more. Sitting in the Atlantic ocean of a flat Earth, you should be able to see America and Africa simultaneously, yet we cannot.
You'll find flat-Earthers claiming this is to do with objects being so far away that they appear small, but the distances across horizons are often shorter than the heights of clouds which you can still see comfortably from the ground, so no dice there.
Also, the higher up you go, the further you can see which wouldn't make sense if the Earth were flat. If Earth was a pancake, being higher up would give you no perspective advantage. Yet, we have a horizon - a limit to vision in all directions, which things appear over (rather than shrinking into) which we can see past only by raising altitude, as I've demonstrated in my beautifully drawn diagram below. Not to scale, obviously.
2. People in Australia can see stars Europeans can't
If the Earth truly was flat, the "northern hemisphere" would really mean the "inner circle" around the pole. Countries in the southern hemisphere like Australia are near the edge of the disc (as shown in the picture at the top of the blog). If the Earth is flat, people in these two circles will be looking at the same sky and while they might disagree on where the stars are, all the stars should be visible. But that's not what we observe at all.
In Sydney, for example, you can't see Ursa Major, which everyone in Europe is pretty familiar with. There are some parts of northern Australia where you can see it at certain times of year (again near the whole Horizon thing) but in the South, you just can't. Likewise, from northern Finland you can't see The Southern Cross (which Australians are so familiar with they have it on their flag).
Now to be fair, flat-Earthers point out that Australians and Europeans will see stars in different places because they're both looking "up" at different points of the Earth's surface, and I agree with them, but it doesn't explain why some stars are completely hidden.
If you and a friend stand on opposite sides of a room and look up, you will see a different part of the cieling above you, you'll disagree on where the light-fixture is but you both still see the light, it's not hidden from anyone.
But what we experience in reality is that some features of the sky cannot be seen in the North and vice versa. How can two people both look upwards, yet be looking in the opposite direction? Their "grounds" must be opposite to each other as well i.e. they are standing on opposing sides of the Earth.
As I've tried to show this on the diagram below. In a flat Earth, the UK and Australia should be looking up at similar skies as they're on the same side of the North pole. But in a round Earth, there are some stars the Australians and people in the UK simply can't see. Technically, I should point out that the opposite country of Australia is actually Spain, but you get the idea...
3. Day and Night happen at Different Times
OK, a similar idea to the previous one. When it's daylight in the UK, it's the middle of the night in Australia (I've skyped with Australians and this is definitely true). This poses no problem to a round-Earth model because as the Earth rotates, different parts of its surface point toward the Sun. Now, the flat-Earth counterargument does initially seem sensible. They argue that day and night work like this:
Here we get the timezones occuring in the right order and day/night cycling back and forth. The Sun hovers above the Earth and goes around in a constant circle, with the moon in opposition. This does solve the day/night problem, but it raises countless others (not to mention how the moon is sometimes visible during the day). I'm going to ignore the problem of having a Sun that size (short version: it's not possible) because I want to stick with simple proofs anyone can test. And there are plenty of ways in which the above can't be right.
Firstly: This isn't how light works. Get a torch and shine it down on a plate. You'll notice that one part of the plate is forming a little circle of "daytime" - fine. But lower your head to the plate and look up. You can still see the torch, even from the dark regions. On a flat Earth, the Sun should be visible, even during night-time.
There's also the problem with the shape of that light patch - it's an oval. It has to be in order for day/night times to occur at the right times, but why would a spherical Sun be creating an oval light patch? This isn't what light does. The only way to get an oval shap from a spherical light source is to have the ground curving...which defeats the whole point of the flat-Earth. Simply put, the flat Earth model means you also need to reject the theory of light as well.
Secondly: This wouldn't explain sunsets. If the Sun were moving around in a circle like that, we'd see it getting smaller and smaller as it got more distant, before gradually growing in size as it "rises" again. But that's not what happens, the Sun stays the same size - suggesting it's always the same distance from us. Sunsets just wouldn't happen in the above picture.
Thirdly: Circular motion doesn't work like that. For an object moving in a circle, some kind of influence must be pulling it toward the centre (what's called the centripetal influence). You can prove this by swinging a ball on a string and notice that the force pulling on the ball is your hand. If the Sun is looping around in circles, there must be some kind of force pulling it in toward the centre, and there isn't anything hovering over the North pole.
You might immediately say it's the gravitational pull of the moon, but there is a major problem with that, which I'll get to in point 10. And if the Sun really is moving in a circle as described, we'd have to abandon the first law of thermodynamics because something is pushing the Sun round constantly through the atmosphere, generating energy from nowhere. And even if we did accept gravity was holding the Sun and moon in place, their orbit would actually look like this:
4. Eclipses happen
Every so often (as perfectly predicted by the round-Earth model) the moon is shadowed by some object. This can't happen with the flat-Earth because there is nothing between the Sun and moon. In the flat-Earth view the moon always has direct line of sight to the Sun so nothing should ever get in its way.
Flat-Earthers do accept this criticism incidentally, and so have come up with a solution. There's another object floating above us: the shadow object. We've already seen there must be a third object in the sky holding the Sun in place (completely invisible), but now we need a fourth to explain lunar eclipses. This object interacts with sunlight (in order to cast a shadow) yet is somehow invisible from Earth - implying it doesn't interact with sunlight?
The same is true the other way round. Solar eclipses can happen in the middle of the day i.e. the Sun is directly overhead and some object drifts in front of it, obscuring it from Earth. There's no doubt the object causing Solar eclipses is the moon (we can watch it happening) so to create a solar eclipse in the above model, the moon would have to spontaneously duck out of it's orbit, drift across the planet and go UNDERNEATH the Sun. When solar eclipses happen, nobody reports seeing the moon shooting across the sky to get in position.
Interestingly, the FES does address the issue of the lunar eclipse by inventing the shadow object (and also making sure it breaks the known laws of optics), but they are strangely silent on the issue of a solar eclipse...apart from a few who pose the existence of yet another heavenly body "the anti-moon".
5. The Sun illuminates clouds from below
Take a look at the beautiful image above. You can see the sun setting (bottom half disappearing first, then top half) and interestingly, the light is hitting the undersides of clouds. You can watch this phenomenon during almost any sunset. Now here's the thing, according to the Flat-Earth model, the Sun is circling above the clouds.
Even if we somehow accept that the sunset is an illusion (I don't, but let's just say) how could we explain the Sun, above the clouds, illuminating them from below? It can't be reflection on the sea's surface because reflected light always bounces off at the same angle it hits (i.e. the sun's rays would be too low to hit the clouds), yet somehow we get illumination on the underside.
1 - 5 Refraction and Perspective saves all
If you've read any flat-Earth literature (and I've recently read a lot) they have clever-sounding answers to the above problems which, without fail, explain it as a side effect of "refraction" or "perspective". Refraction causes light to change direction when it goes from one substance to another and you've probably done experiments with prisms in school, or seen straws appearing in wierd places in glasses of water, or swimming pools seeming shallower than they really are. This is the kind of thing refraction can do. Perspective is what makes objects look smaller as they are farther away.
However, according to flat-earthism, refraction is some magical phenomenon which allows light to bend and twist in any way you can think of. Sunsets, sunrises, eclipses and the horizon are all explained in flat-earthism with a simple "because of refraction and perspective" defence.
But refraction and perspective can't make the Sun move down when it should get smaller, it can't make the top of an object appear before the bottom, it can't bend light upside down to illuminate clouds, it can't make stars invisible and it certainly can't bend shadows. But, let's just say, let's just say we accepted flat-Earthers claims that refraction and perspective explains away all my evidence above. The next five tests don't have anything to do with either of them.
6. Water boils at 100 degrees
This one's a really easy test. When you heat water it moves around more. It also expands and turns into vapour, leaving the pot and carrying away into the air. The more air above you, the harder it is to get the water to leave the pot. By contrast, the less air above you, the easier it is to force the water upwards (less air fighting it back down).
The idea that water boils at 100 degrees is only half the story because it actually boils at lower temperatures when you're on top of a hill (less air above you so less heat energy needed to overcome it), and if you put it under lots of pressure (like a pressure cooker) you can have water well over 100 degrees in liquid form.
Now, in the flat-Earth model, there are two ways of accounting for the shape of our atmosphere. Either the air goes on forever in all directions or it forms a dome. If air is infinite then going up a hill should make no difference to the boiling point of water - go up high and you've still got infinite air above you. Which is why most flat-Earthers argue the atmosphere must look like this:
Straight away you can see the problem. The atmosphere is very high near the north pole, but less high near the southern tip of Africa or Australia. In other words, water should boil at a higher temperature the further north you go (the higher the dome is above you).
People in Sweden should be able to boil water at 120 degrees for instance, and people in Australia perhaps closer to 115 degrees or something (probably a more dramatic difference). But that isn't what we observe.
Water's boiling temperature is constantly 100 degees at sea level wherever you are. The only way of changing it is to go higher. And, what's more, the change in height is the same everywhere you go. You can check it for yourself but it's every 290 meters climbed, shaves 1 degree off your boiling temperature. And that principle is also true everywhere - suggesting the height of the atmosphere is the same everywhere. This couldn't happen in a flat Earth.
7. There are two Tides
High-tides occur because the water is moving away from land and forming a sort of watery-hill in the middle of the ocean. Explaining this is impossible under a flat-Earth model (I'll get to why in point 10) but even more problematic for the flat-Earth is that high tides occur on opposite sides of the world simultaneously.
Explaining one tide on a flat-Earth is just about doable. You could talk about the Earth tilting, the moon somehow pulling on the water (not using gravity though), but to explain why there are always two tides at different "ends" of the flat-Earth is something I've never heard a flat-Earther give a satisfactory explanation for.
In a flat earth this amounts to two separate peaks of water spontaneously rising up and moving around the plane of the Earth with no mechanism. The round-earth theory explains both tides very well however. The moon's gravity pulls Earth's water toward itself, but as the Earth spins it throws water out and away in the other direction. The overall effect, predicted by round-Earth theory, is that it ends up creating a lozenge shape and therefore two tides...
8. The colour of the Sky
When you look through a large amount of air you see something different to what you get looking through a small amount. In an airplane, the sky often looks darker above you than it does near the horizon. At sunset, the sky near the horizon looks orange/red while the sky above looks a darker blue. During daylight, the horizon usually looks a bit paler than the sky overhead. There are all sorts of effects going on in these examples but the conclusion is the same every time: thin air is a different colour to thick air.
Now go back to our flat-earth dome. Someone in the north pole should see an even distribution of sky colour because they're right at the centre. But if you live in southern Australia, things are very different. Cast your eyes north and you're looking through ten-times the atmosphere you'd be looking through if you look to the south. The sky should look different colours in different directions. In fact, anywhere on Earth (except for at the pole) you should see this effect, one horizon should be a different colour to the other, because one involves looking through less air.
What we actually experience is a uniform sky colour everywhere. The horizons match during the day and only change during sunset/rise. What kind of shape could possible explain the fact that everybody seems to be looking up at the centre of a dome?
This one gets a bit complicated, but I'll cut out all the mumbo-jumbo and keep it simple. Magnets always have a North and a South pole. It's impossible to get a lone North-poled object for instance, because if one direction is North, the other must be South. By definition, magnetic fields always cancel each other out at both ends and you can't have what are called "magnetic monopoles" (Dirac if you're reading this, shut up).
The Earth has a huge magnetic field which we can test using compasses. The Flat-Earth has the idea of a North pole covered, that's the point where all the magnetic field lines connect. What it has difficulty with is the South pole.
In the flat Earth model, there is no such point as the South magnetic pole so the entire rim of the world has to act as the South pole in order to explain compasses; the field lines branch out from the centre and that's why our compasses point along these axes. There are a few problems with this straight away in terms of how magnetism works, but let's just be generous and say it could happen.
You could imagine a bunch of bar magnets all glued together in a wheel with their North poles pointing to the hub. This magnetic wheel now presents us with three major problems.
First problem: Field Lines Take two compasses and have them parallel to each other at the equator. Except, it turns out you can't do that. In a flat earth model, the magnetic field lines are all pointing away from each other at angles, so two compasses on the equator (which I've drawn below as the black rectangles) will point in different directions. Parallel compasses or magnets would be impossible on a flat Earth.
But let's just say we could do it somehow, let's ignore that problem and assume we somehow could put magnets parallel to each other at the equator, maybe they're really close to each other, too close to see the divergence. As we walked toward the South pole, the magnets are going to follow different field lines and will eventually turn out to be pointing toward two different parts of the South pole - they would spread out.
But that's not what happens. Firstly, the magnetic field lines are parallel at the equator and they end up pointing toward each other the further South you go. How can we have magnetic field lines being parallel at the equator, but converging on a point the further South you go? On a ball, as shown below.
Second problem: Aurora Australis You've heard of the Northern lights and the mechanism is pretty simple. When the Sun ejects clumps of high-energy particles they go flying into space and sometimes get caught in Earth's magnetic field. As they get funnelled in toward the North pole, they end up crashing into the atmosphere. The result is a beautiful light show. It happens at the North pole because that's where the magnetic field lines are pointing.
In a flat Earth, you'd expect these lights to happen at the North pole where the magnetic field is most concentrated, but not at the south pole where the magnetic field is weak. And yet, we do get a light display there, often at the same time as the Northern lights. Many explorers in the Southern region of the world have seen the Aurora Australis for themselves and you can too - it's a bit of a stretch of the term "testable" but you're already walking across the world holding two compasses, why not see the lights as well?
The problem is that the South pole in a flat-Earth is too weak to cause the lightshow. It's the same amount of magnetism, just stretched over a large diameter (the edge of the disc). The only way to make the South pole more magnetic, and permit the lights, would be to introduce lots of "south poles" on their own, but since magnetic monopoles aren't a thing, this is impossible. No way round it I'm afraid, Southern Lights shouldn't exist on a flat-Earth.
Third problem: a Flat Earth shouldn't be Magnetic anyway There's a good reason for the Earth to have a magnetic field. A large sphere of liquid iron is constantly rotating around an inner core of sollid Iron (and Nickel). This grinding of two large ferromagnetic bodies means a lot of electricity is being moved around, and when you have moving electricity you have a magnetic field. In other words, it's a byproduct of electricity moving in a sphere. There's no other way to generate a magnetic field that big.
A round earth comes with a satisfactory explanation for why it has a magnetic field - which matches everything we know about electricity and magnetism (and can test). A flat earth provides no explanation for why the Earth even should be magnetic in the first place. How would a magnetic field be generated on a disc?
Which brings me to the big one. The one I've mentioned a few times and held back. In flat-earthism, it's impossible to have the Sun going round in a circle because of a rather bizarre feature of Flat-Earth theory which all flat-Earthers have to accept. It's not usually the first thing they come out with but the day/night model they rely on so heavily cannot work because it relies on the existence of gravity, and guess what...
10. Flat-Earthers do not Believe in Gravity
I've included a screenshot here of me pointing to a statement on the FES website, just so you know I'm not making it up...
There are two reasons Flat-Earthers think gravity doesn't exist. The first is that any object has a centre of mass, a point which gravitationally pulls other objects toward it (I'm simplifying it a teensy bit there A-level physicists). The centre of Earth's mass is in the centre obviously, and gravity points toward it. In a round Earth this is no problem because anywhere you stand gravity pulls you inward toward the core. But on a flat Earth gravity would pull you sideways at the edges of the world. Australian gravity would happen at an angle and it clearly doesn't. Flat-earthism and gravity don't go together. So rather than abandon flat-earthism, they abandon gravity.
Secondly, gravity pulls things into a sphere. That's what it does. Every Sun in the sky, every planet, every moon, every pulsar, every quasar are all round. Gravity pulls in all directions and so, like a piece of paper crumpled from all sides, everything gets rolled into a ball. A big flat object (like a flat Earth) couldn't exist for long. It would buckle under its own size and gravity would crush it together to form a spheroid. In other words, gravity is the ultimate flat-Earth killer. So, naturally, flat-Earthers reject it. As it says on their website "objects simply fall".
Except they don't.
In 1774 a group of Scientists carried out an experiment (repeated countless times by enthusiastic physicists and one you can do it yourself) where you hang a pendulum next to Schiehallion mountain in Scotland and the pendulum doesn't hang straight down, it tilts toward the mountain. Of course it does, the mountain has mass, so it has a gravitational pull and causes things to tilt as they fall, rather than in a straight line toward the earth. Objects do not simply fall.
You can watch the moons of Jupiter through a telescope orbiting their planet in a circle. Gravity is the only way to explain this circular motion. Objects do not simply fall. The tides show the entire ocean gradually lifting up and pointing toward the moon wherever it moves. Objects do not simply fall. The infamous Cavendish experiment (which you could also replicate) shows two large spheres being attracted to each other, not toward the ground, because of their gravitational attraction. Objects do not simply fall. We can watch, through our telescopes, clouds of dust being pulled together to form Suns, woven by some invisible all-pervading force. Objects do not simply fall.
And even if they did, even if they did, why isn't the Sun falling toward the Earth in the flat-Earth model?? If objects simply fall, then there is nothing holding the Sun up and it should just crash into us, along with the moon, the shadow object, the anti-moon and so on.
As we showed earlier, a Sun moving in a circle needs to be held in place by something. It can't be gravitationally attracted to the moon because gravity doesn't exist in flat-Earth world. The tides can't be explained by the moon's influence either. Ultimately, the flat-Earth theory has to reject gravity, but in doing so, you also abandon the concept of day and night as well. No matter how you look at it, gravity is the nail in the flat Earth coffin.
What you have to believe
Believing in the flat-Earth isn't simple. In order to match what you see to the flat-Earth, you have to also give up on light and optics. You have to reject the first law of thermodynamics. You have to reject the existence of tides. You have to reject electromagnetism. You have to reject gravity. And all these ideas are testable and endlessly verified.
Yes, some of the things flat-Earthers point out are puzzling at first, and some of them don't have immediately obvious explanations. But I'm afraid that's all they are - quirks of perception which can be explained with a better Scientific understanding. Round earth theory has survived not because Scientists said it was true, but because it accounts for every bit of evidence, making countless testable predictions.
The Earth is round and anyone saying otherwise is not crazy, or stupid, they just don't understand the gravity of their claim. Pun intended. James out.
Flat Earth map: Wikipedia
Flat Earth equations: The Flat Earth Society Website
Matilda: Miriam Ruiz
Horizon: Mariza Knezevic
Day and Night: The Flat Earth Wiki
Saucepan: Shauna Xani
Northern Lights: NorthernLightsTours
I remember standing in the ICT office at school once, discussing the new Star Wars movie, when someone walked in and said "you guys are such geeks". I looked at her and said "you realise that's not an insult to us? I teach Science for a living and these guys are ICT wizards; geek is absolutely the correct word!" Zing! But it's defintely interesting that Sci-fi fans are often STEM-minded people too. Why is that?
First, we have to accept that fiction itself (let alone Science fiction) is a very weird thing. I mean, why do we like hearing stories which are fake? It would make sense for humans to be invested in hearing true stories, but why do we get so excited by events we know never took place?
Every evening before bed, I sit down and read. I read plenty of non-fiction, but I also read novels and short stories. I spend hours doing it and have so many fiction books I overspilled my shelves years ago. I'm also a movie nut. Every weekend I go to the cinema and see whatever the new release happens to be.
But what a strange thing to be interested in. I spend large amounts of time and money reading/watching stories which are - no other way of putting it - lies. Rather than being angry at a storyteller for trying to decieve me, I welcome the experience of made-up tales. I'll even criticise a film if the actors aren't convincing...if they've failed to lie to me. If I see through their performance and remember they're not really their character, I'm annoyed because it reminds me it's just Nicholas Cage I'm watching, rather than his character.
Sometimes we even prefer fictional stories to reality. The highest grossing films are never documentaries and the bestselling books are always novels rather than non-fiction. We talk about what happened on Doctor Who more than we talk about what's happening in the UN, we cry at movies when something emotional happens to a character who never existed, and we write blogs listing our favourite fictional Scientists.
There are scads of essays by literary theorists on why humans enjoy fiction and how good stories are told. There's also a bunch of nonsense about how the mind works and how all stories follow the same structure (looking in your direction Joseph Campbell). I'm not going to argue my own views on why storytelling matters, or why I think these literary theorists are wrong. Instead, I'm going to focus on my all-time favourite genre: Science fiction.
But isn't that even crazier?! I'm a man who's dedicated his life to promoting real Science, and I absolutely love movies which lie about it. Why do I love movies in which the main characters can shoot lasers from their hands, travel in teleporting police-boxes and go to war with alien races? After all, my ultimate passion is getting people Scientifically educated...
What exactly is Sci-fi?
There's a word for all of those geeky genres they stack next to each other in Waterstones: speculative fiction. This encompasses things like horror, fantasy, sci-fi, alternate realities, steampunk etc. etc. All fiction is made-up, but speculative fiction refers to stories which are so far away from reality, you'd immediately know it wasn't true if you heard it.
If I told you the story of Girl on the Train for example, I could easily convince you it was true. It has murder, adultery, depression and alcoholism in it - they're things which are known to happen in the real world. But if I told you the story of Conan the Barbarian, you'd immediately recognise it wasn't true. Magic doesn't exist...as far as you muggles know.
I've met people who consider Sci-fi to mean "things which take place in the future". But that immediately removes something like Back to the Future, which takes place in the past. Or what about something like Independence Day which is about alien invasion in the present day? Or even Independence Day Two which is about what happens to a franchise if it's been left for decades and the director returns and fails utterly, utterly, to capture the fun of the original.
I want to avoid giving the horrendous answer of "I know it when I see it" so here's my approximate definition of Sci-fi which I think covers 95% of cases: Sci-fi is a genre in which Scientific laws match those of the real world, but Scientific knowledge does not.
What I mean is that Sci-fi takes place in a reality where there are unbreakable Scientific principles which the story must obey, and they are the same as our Universe's - but there are also fictional Scientific ideas as well e.g. discoveries which haven't been made, technologies which aren't invented etc. etc.
Terry Pratchett, author of the Discworld novels, once said he preferred writing fantasy to Sci-fi because in fantasy there are no rules; you can bend the world to fit your story. In Sci-fi you have to follow Scientific law.
For Harry Potter, magic is a real thing and it can be used to achieve anything JK Rowling wants it to. Need your characters to fly? Magic. Need your characters to turn into other people? Magic. Invisibility cloaks? Magic. This isn't a criticism by the way, I've got nothing against the fantasy genre, but in fantasy you can have anything happen and justify it by saying "magic did it". In Science-fiction, if you want anything to happen, you have to give a plausible justification.
Optimus Prime is a sentient robot (not yet known with current knowledge) but his evolution is explained in terms of cybernetic advancement (permitted by the laws of Science). He can travel from one planet to another via a spaceship, but he couldn't just wave a wand and delete Megan Fox from existence (as much as we might want him to). For him to cast a spell would break the rules of the Transformers Universe, because they're the same rules as our universe.
Sci-fi isn't set in the real world but it's set in a real world that could be ours. Laser guns and light-speed ships aren't things which exist, but they might one day. Fantasy tells stories of the non-real and impossible. Sci-fi tells stories of the non-real but possible.
What about Batman?
There are some grey areas to my classification system because genres of fiction, like species of living creature, don't always fit neat categories. The obvious example is good ol' Batman. Batman is set, more or less, in the real world. He has no superpowers and doesn't use magic, he's just an ordinary guy who has a lot of tech and time on his hands.
Occasionally, Batman stories veer into Sci-fi territory (or even fantasy) but the majority of Batman's adventures could, theoretically, happen in today's world. It would be possible for someone to dress up as a bat and go round fighting crime. In fact someone already has. Look up "The Bromley Batman" - I promise that news story will brighten your day.
There are other franchises which blur the boundaries. In Warcraft for example, there is magic, but the magic is given a set of rules and structures which mimic Science. It's a parallel Universe that has underlying laws, they're just different to the laws of our world. Or take The X-Files which sometimes covered stories of aliens (plausible), but sometimes stories of ghosts (debateable) or werewolves (nonsense).
Even our beloved Star Wars is set in a mostly Sci-fi world, but includes The Force, which is basically magic...
There was a time (and by that I mean, all of history up until the late 1980s) when speculative fiction, and Sci-fi in particular, was sneered at by those in proper literary circles. Science fiction was often associated with cheapness and popular writing - because heaven forbid anything popular be considered worthwhile. I've read plenty of essays from the early 20th Century, most of them hitting peak venom in the 1960s and 1970s, condemming Sci-fi as a childish genre, even accusing it of making people stupid (Quite the opposite is true incidentally, as many Scientists originally got interested in the subject from childhood Sci-fi).
In an attempt to quel this snobbishness, Isaac Asimov suggested we divide the genre into two categories. Sci-fi was the cheap thrills stuff - quickly written, predictable, sensational stories with 2D characters and terrible Science, and then there was "Science fiction" - carefully written, literary works with carefully drawn characters and well-researched ideas. For a time, this disctintion was necessary but nowadays people are less uptight about it.
Today Sci-fi and Science Fiction are synonymous, we just recognise that some Sci-fi is good quality and some is not, the same with any genre of fiction. Thanks to novelists like H.G. Wells, Isaac Asimov, Robert Heinlein, Richard Matheson, Arthur C. Clarke, Neal Stephenson, Eric Brown, Richard Paul Russo, Kevin J. Anderson, Aldous Huxley, C.S. Lewis, Dan Simmons, Alan Moore and Phillip K. Dick, literary circles are finally starting to recognise that some Science fiction is the work of truly talented writers creating masterful works of fiction...it just happens to feature laser-swords.
Besides, the very first work of Science fiction (Frankenstein as far as I'm concerned) is a masterpiece and a deserved classic. Yes, Sci-fi has its cheap rubbish, but so does the well-respected genre of emotional human drama...I mean have you ever tried to read anything by Nicholas Sparks?
So what's the big deal?
I can't speak for every Scientist but I can definitely explain why Sci-fi is important to me. It's because Sci-fi, more than any other genre, asks the question "what if?" Sci-fi imagines worlds different to our own, but not so different as to be out of reach. Sci-fi is about possibilities and it's this optimism I'm enamoured with. Sci-fi offers us something more tantalising than fantasy fiction...something which might just be possible one day.
As a Scientist I'm always interested in finding out how the Universe works but that's not all there is to it. Scientists also want to know what is possible. If you put our knowledge of nuclear physics to good use, for example, we get power stations, use it for aggression and we get the cold war. Science is a powerful instrument in our species' evolution and I think it's healthy for us to speculate about the possibilities - good and evil.
I don't know why fiction as a whole is important to us, but I doubt anybody does. Perhaps it's because we like to connect with people so much that even fictional people will do. Perhaps it's because we want to invest in people's lives without the stress and worry of "real-life drama" - you can put a book down when you're not in the mood. Or maybe it's just that we all want to go on adventures and experience the world, so we allow ourselves to do so through imaginary stories.
Whatever it is about fiction that appeals to us, Sci-fi plays on another important human desire: the desire to ask questions. We want to find out about the strange edges of human knowledge, to find out what the world is like and how we could make it different. We like to imagine different worlds because it helps us put our own world in perspective. And that's why I love Sci-fi. Not because it allows me to escape reality, but because it puts me fully in touch with it.
Also, spaceships and robots.
Lightsaber geeks: Wired
Voldemort and doctor: Gawker
Jetpack: Tom Gauld
I love science, let me tell you why.