Usually when people talk about Science they mean subjects like Physics, Biology, Chemistry, Astronomy, Geology etc. If you look through any Science text-book it’s essentially a list of facts the author seems to just know. What’s often not included is the story of how the facts are discovered.
This approach to Science is unfortunate but inevitable. If books explained how each fact was arrived at, they would be fifty times the size. The problem is that people often come away from Science seeing it as knowledge rather than method.
Science ought to work something like this:
Let’s start at the top. All Science begins with not knowing something. Science is born in ignorance. Maybe we don’t know what happens to apples when we let go of them, maybe we don’t know how often chimpanzees fight in the wild or maybe we don’t know what will happen if we mix two chemicals together.
First thing: get out and do an experiment. The alternative is to try and work everything out in our heads, what’s called a priori thinking. Science tends to reject the a priori approach because it makes the assumption that people think perfectly. Science assumes that even brilliantly clever people make mistakes, so nobody can just decide what is true from their own brain.
After the experiment we’ve got some information. We might have discovered that all apples fall, that chimpanzees fight once every hour and that the chemicals turn blue when mixed. Sometimes people think this is where Science stops. But this is just the beginning because although we’ve learnt a simple fact about the world, we’re lacking an explanation. So we come up with a “hypothesis”.
A hypothesis is another name for an educated guess. It’s a potential explanation which must explain everything, not contradict itself and, most importantly, it must be falsifiable.
Falsifiability is a key principle of Science. It’s the idea that a hypothesis must be capable of being proven wrong. I’ll show what I mean by using “Sagan’s dragon”. Suppose I claimed to have an invisible dragon living in my house who made the Sun rise. Not only is he invisible but he floats and never leaves footprints, he is non-corporeal so you can’t throw a blanket over him, he’s also silent and he gives off no heat signature. In fact there is no way of detecting his presence at all, but he’s definitely still there. Prove me wrong.
Such a hypothesis does provide an explanation for what makes the Sun rise. In fact, it might be true. There really might be such an invisible dragon living in my house. But if you can’t prove the idea wrong, how do you test to see if it’s true? The problem with a non-falsifiable hypothesis is that if we accept it we have to ask: why not an invisible walrus too? Or an invisible fish-wizard? Why not an army of undetectable pixies living in my washing machine who control the weather? Our world may be filled with such creatures and we would never know it.
If you accept one non-falsifiable hypothesis, you have to accept every other one since they have an equal amount of evidence (none). Our picture of the world quickly becomes infinite under such a view. It might really be like this, but we can’t know with any confidence so we have to ignore all such claims, not because we think they’re untrue (they might be right) but because they are un-knowable.
So once we have our hypothesis locked, we put it to another test, one which measures it specifically. This is the kind of thing we learn about in school as “fair testing”. Remove anything which could throw the results off and anything which could be a distraction. Arrange it so that only one thing is changing and one thing is being measured.
Then do your test repeatedly. This is to get around coincidences. Even the simplest “sugar dissolves better in hot water” hypothesis has lots of potential misleading factors. The temperature of the room, the quality of the sugar, the type of water etc. So you test it over and over to make sure the hypothesis wasn’t confirmed or rejected by accident the first time.
At this point your hypothesis is either proven wrong or it looks hopeful (note: we don’t say we’ve proven it right, just that we could be onto something). Thing is, we’re human. We want our idea to be correct because we’re proud of it. If our hypothesis is proven wrong then it’s completely normal to get frustrated or disappointed or feel like we’ve wasted our time.
In an ideal world, proving a hypothesis wrong would be seen as good, because we’ve still learned something, but humans aren’t ideal and it can be difficult to think like that. Even a hard-nosed Scientist must feel a slight pang of annoyance if their hypothesis fails.
We do our best to put up our hands and say “oh ok, I guessed wrong, back to the drawing board” but we’re full of emotional biases and the desire to achieve positive results (even though negative ones are just as useful).
In addition to these instinctive responses there are all sorts of other things which could make our conclusion faulty. Bad equipment, poorly designed tests, mistakes carried out by accident and even conscious dishonesty. That’s why Science introduces the next crucial stage: we bring in other people to check it.
You cast your hypothesis on the ravenous mercy of other Scientists and hope for the best. This is frightening because you are opening yourself up to heavy criticism, but it’s vital. If you’re doing Science in your kitchen then get your friend to check your results, but if you’re working in Scientific research the standard way to release your results is to submit them to a journal (a sort of weekly Scientific newspaper).
The journal’s editorial team will send your article to other researchers in the same field to find flaws. This is usually done anonymously (to avoid bribery etc.) This is an ingenius idea. You are essentially showing your work to your rivals, the people most likely to criticise and destroy. If they can’t find fault then your hypothesis has passed another hurdle and the results are published.
Now we have a public hypothesis so other people can test it. If other people find your hypothesis holds up then you can start to get excited. But if they can’t reproduce your findings then you swallow pride, abandon ship and start over.
But let’s say you’re lucky. Let’s say you’re in that tiny fraction of a fraction of people who come up with an accurate hypothesis. This is when it picks up speed. Once the hypothesis has been tested many times by lots of people over a long period of time and has been confirmed on every occasion, explaining every result, then we decide the hypothesis is probably correct. The hypothesis graduates from speculation to confidence and people start referring to it as a “theory”. A theory is not one person’s guess. It’s a statement about the world which has been put through the grinder and stood the tests of both time and savage scrutiny. But we don’t close the case because the Scientific method goes round in a circle.
We might use words like “Scientifically proven” or “Scientific fact” but these are shorthand for what we really mean. No theory is beyond question. Ever. A theory is something we’re 99.99% confident of. These are the facts we publish in our text books and teach in our schools. But any theory is based on falsifiable ideas and a single piece of evidence can bring it crashing down. Rightly so.
Take gravity. Isaac Newton drew up a hypothesis to describe the attraction between two objects in 1687. The more people tested it the more confident they became, and pretty soon we had a “theory of gravity”. A Scientific fact.
But later measurements of Mercury and its orbit around the Sun turned out not to fit Newton’s theory. So, rather than sticking to Newton blindly, we decided his theory of gravity was incomplete. Newton was wrong.
Then, in 1915, Einstein published his own ideas on gravity which would explain the anomalies and account for why Newton had seemed correct up until then. It was tested, shared and confirmed over and over. Today we call it Einstein’s general theory of relativity. But we don’t say job done and declare Einstein’s theory iron-clad. In fact, Einstein’s theory seems to break down in certain circumstances so we still don’t have the complete picture.
The key point is this: if, at any point, someone had declared their knowledge of gravity complete, they’d find themselves looking pretty stupid a few years later. Scientists are aware of this so they’re very reluctant to make bold claims unless they have incredible evidence on their side. Most of the time Scientists guess wrong and they know it.
Ultimately, Science is a self-correcting, painstaking endeavour making progress at a rate of inches per decade. It’s cautious about what it says, so when it does say something, it has a good reason to do so. But that’s only a theory of course. Eventually we might discover something better.
I love science, let me tell you why.