How Science Works

Recently, I found myself in a discussion around science, religion, and whether or not god exists. It was fun.

But I was slightly frustrated by it, too, because the person I was talking to demonstrated a slight misunderstanding on how science works, what science, in effect, is, that to me is at the heart of any debate over whether or not science can answer questions like the above. It’s not the first time I’ve seen this misunderstanding.

There are good examples of explaining the scientific method around; much better than I can sum up in a few words on a blog. However, you don’t need to understand all the bits and piece to understand the fundamentals.

The problem is, when people talk about science or scientists, they tend to talk in simple sentences suitable for headlines: scientists prove that [insert subject here].

In most cases, that’s not just a newspaper headline badly summing up an article that badly sums up one or more research papers. It’s fundamentally wrong, in that it demonstrates a misunderstanding of how science works. The thing is, science — or scientists — rarely if ever prove anything.

Before I explain, that’s not to suggest that your trust in science is misplaced. Science has discovered an immeasurable wealth of facts about the universe that lets us understand and manipulate our surroundings in ways undreamed of a mere few centuries ago. You can trust science.

But science is not in the business of proving things. And in part, that’s due to a difference in how scientists use the word “proof” and how the same word might be used in other contexts.

To a scientist, there exists only one type of proof, and it’s mathematical. Or, to put things differently, there is no such thing as “scientific proof” in any scientific discipline other than mathematics. To those who understand mathematics well enough, that becomes obvious: mathematics is the only discipline that operates entirely in a world of it’s own making; the rest of the scientific disciplines try to explain the real world instead. Finding proof with the same claim to absoluteness in the real world as is possible in an imaginary world is an exercise in folly1.

By way of explanation, it is easy, for example, to prove that n + m = p because, well, that’s how things are defined to work with real numbers. Mathematics made up the rules for real numbers, specifically so that this type of proof would work. Of course, mathematics doesn’t stop there and made up some more rules, which are overall supposed to reflect how numbers happen in the real world. From those rules mathematicians can derive more and more mindboggingly complex proofs, but ultimately they work because mathematics made up the rules by which mathematics are governed2.

Of course mathematics doesn’t stop there, and defines different rulesets for different number spaces, such as the imaginary numbers. And all of these rules of mathematics can be used to describe all sorts of interesting relationships between numbers, which is why every other scientific discipline relies on mathematics to a lesser or greater degree.

So how does “proof” exist in other disciplines?

Well, as long as you’re just trying to describe numbers and their relationships, you’d tend to use mathematical methods, and may be able to arrive at mathematical proofs. While that may be useful, it’s not as important as ensuring that you’re looking at the important numbers, and see the important relationships, though. In fact, picking the numbers you look at just right is vital to arriving at any sort of scientific conclusion, period. Or doing science, to put it differently.

So scientific proof can then be thought of as proof that you picked the right numbers.

Say you want to examine whether children that play video games a lot act more violently than other children. You put some kids in front of a violent video game, and some in front of a non-violent one. You then let them watch news footage of war and misery, and monitor which of the kids responds to it with a raised heart rate. In case you’re interested in the whole thing I’m referring to, there’s a good article that goes into details on the setup, and why the conclusions drawn are anything but convincing. Go on, read it. I’ll wait.

The point is that picking the right numbers is so crucial to the validity of the conclusions that it’s essentially the black art of science itself. Did the kids play long enough? Was there a long enough pause between the gaming and the news footage? Can we be sure there is no other factors influencing them? The list goes on.

Let’s be generous and assume the above was a good scientific setup with a control group (e.g. kids playing with plastic guns in the playground), and the whole shebang. Let’s assume that people weren’t monitoring the kids’ heart rate, but gathered less ambiguous data, such as blood adrenaline. Let’s assume there’s a strong correlation between kids that played violent video games and whatever the scientists were measuring as a response, in other words.

Does this constitute scientific proof? No.

Scientists get taught that correlation isn’t the same as causation; that is, just because two facts occur at the same point in time or shortly after the other does not necessarily mean one is caused by the other. Not necessarily, but of course still possibly. Much of the so-called “proof” in science is merely documented cases of correlation.

Don’t get me wrong, it’s good to know these things. Gather enough of data like this, and you might find yourself being able to form a good theory of how they might all work together. Amassing incidents of statistical correlation is a vital tool in the scientist’s arsenal. Proof it is not, however.

  1. Nevertheless, religion makes that claim. ‘Nuff said. []
  2. I once joked to a friend of mine very much into the social sciences that because of this property of delivering absolute proof, mathematics can be considered the only “real science” — to which she wittily replied that alternatively it could be considered the only one that’s not. []
  • eremit

    Well done and I agree to the fullest. People often mistake the cumulation of the same result as a proof and totally miss to take a look on the context (setup).
    Also the fact that science is mostly about ratios, which defines if a theory can be considered as true or false, is often forgotten or plainly not understood.

    • http://www.unwesen.de/ unwesen

      Did I not reply to this? Hmm. Yes, indeed, science is quite a lot about ratios. Binary truths are more convenient, though.

  • http://univers-sans-frontieres.org/ Thibault Cantegrel

    Well done indeed Jens.

    I often try to explain modeling instead. Our brain makes models of our environment, allowing us to reason and deduct (and ultimately anticipate) based on these models. Each experience of the life fitting one model, makes us more confident this model is good. One single disproving experience forces us to revisit our model, try to find a better one, or leave with a model we know it is not perfect but really helpful anyway for major cases. The only proof science can bring onboard, is that a model does not fit the real life experience.

    And at the end of the day, all the models humanity have defined to better understand our environment are known as approximative or false in some extends (which make us humble).

    There’s no proven theory, then. Just models better (more helpful) than others.

    And, of course, religion has nothing related to this, as it is all about believing (which can be as well helpful for people). It does not have to go against science and vice-versa (one can believe the Earth is flat if it helps him, even if all scientist models don’t “fit” with this belief).

    • http://www.unwesen.de/ unwesen

      I agree, religion has nothing related to this. I also agree that this does not mean religion is bad as such, or needs to be pitched against science.

      What bothers me – and this is sidetracking a little – is that religion tends to encourage dogmatic belief in any sort of truth, and therefore encourages… let’s say mental incompatibility with the scientific method.

      That this doesn’t need to be the case is obvious. A friend keeps pointing out to me that the Dalai Lama supposedly encouraged throwing out scripture that does not reflect the advances of science. He’s still a great spiritual leader that many people admire, and ultimately derive comfort and hope from – which I can’t see as a bad thing.

      • http://univers-sans-frontieres.org/ Thibault Cantegrel

        I agree with you Jens. Religions in general tend to encourage a dogmatic belief of the truth as you said, locking people in a mind set that is incompatible with scientific thinking.

        Fortunately, a lot of well educated believers in our non-religious countries (I mean our EU countries here), can find a modern teaching of the religion, open minded, that will not necessarily preach the truth (and sadly an integrist one as well).I’ve always been fascinated by scientists who still believe. It seems there’s room here for cohabitation of scientific thinking and religious belief.I hope religions will modernize themselves, and move away from preaching the Truth (“it is not about facts, but messages”), so that they can get compatible with other modern religions and scientific thinking.

        • http://www.unwesen.de/ unwesen

          For my own part, if religion is not about facts but about messages, then there is no point in religion. You can bundle the same messages in a non-religious context. Doing so might also make it easier to ensure the messages are kept up-to-date with the times, too.

          But as far as the topic at hand is concerned, I can only agree with you.