What do we really know, anyway?

What does science tell us about the True nature of things? To deal with this issue, I like to distinguish between two kinds of truth. There's "truth" with a little "t", and then there's "Truth" with a capital "T". The first, "truth", is that which we all can perceive and discuss, which generally boils down to the five senses. But that's not Truth (with a big T). A physicist will tell you that when you look at something, your eye is absorbing photons scattered or emitted by the molecules in that object. But you don't see the molecules; you don't even see the object. What you see is electromagnetic radiation, converted into nerve impulses, processed in your brain. That's "truth" with a little "t". It's amazing that despite all that processing, most of us can agree about what we perceive!

To get at "Truth" with a capital "T", answer this question: Did Isaac Newton discover gravity, or did he invent it? If he discovered it, then gravity must be part of the "Truth" since it exists completely independent from any of us. But if he invented it, then it's just a handy way of generalizing one class of phenomena we all experience as "truth". To give you a feeling about which way I'm leaning here, I'd like to remind you that Newton's gravity, where one mass attracts another by subjecting it to a force through space, is just one way to explain the concept of gravity. Another is an exchange of gravitons, or gravity particles, between masses. Another is Einstein's Theory of General Relativity, where masses curve the very fabric of space-time, and this curved space-time tells other objects how to move.

So truth (with a little "t") is the world of phenomena (or facts), while Truth (with a big "T") is the world behind all of the phenomena we observe. Philosophers might call this the world of noumena. When I say science can be defined as a body of knowledge, this refers both to the phenomena, which are the facts or the data, and to the explanations, which are an attempt to describe the noumena behind the phenomena. Going back to the example of gravity, we can all agree on the facts, which is that things keep falling to the ground unless supported. It's the explanation for this phenomenon that's trickier. It's not a fact in and of itself, but it does explain what we experience quite well. The tricky part is that there isn't just one acceptable explanation for what we call gravity, there's three.

This is why I'm hesitant to describe science as a body of knowledge, even a collection of facts. The collection of data grows with time, and the explanations for these data change. What we know is the result of science, not science itself.

Some might get the impression that the data and the theories aren't particularly useful, since they're all going to change at some point anyway. The goal of science is to improve our understanding of the world around us, and it's these products that get us there. Sure, we can do better in the future, and we will, but it's the best we've got right now.

Just to put this into perspective with our example of gravity, it's true that Einstein's theory is more accurate than Newton's Laws, but in the everyday world, the answers you get from the two are for all practical purposes indistinguishable. And Newton's Laws are much simpler to apply. It's only when circumstances become quite bizarre compared to our everyday world that the added complexity of Einstein's theories becomes worth the trouble.

There are those that will disparage a scientific idea by saying, "It's just a theory." By now, you have probably realized that it doesn't get any better than that. You start with an hypothesis, and even that has to be somewhat consistent with the data to even be considered. Once this hypothesis has survived numerous tests, then it will get described as a theory. Nothing becomes a law anymore; that's a relic from the old days when scientists really believed that they were uncovering pure and fundamental "Truth". In fact, these days, most accepted hypotheses don't even get called theories. In astronomy, especially, we talk about models. The model represents in some way the fundamental physical processes producing the phenomena we observe. A good model is one that's been around a while. It doesn't mean there might not be a better one out there somewhere, but if it's useful and produces accurate results, then why not use it?

If you wish to read on, continue to the pseudoscience page, where I'll give some examples of the dangers of not being disciplined when searching for knowledge.

Home Science

Last modified 14 February, 2003. © Gregory C. Sloan.