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.

The 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 

Image credits:
Electric Six album: Junostatic
Prometheus Movie: amazonaws
Burning Man: business insider
Spherical Flame: cloudfront
Chris Evans: becoming the muse