"Science" has many meanings, depending on what one is talking about. Most people who speak of science use the word badly. They use the word to speak of things that are not really science. Sometimes it is because they do not understand, sometimes it is because they do not care about using words correctly, but they want to sound clever.
What I say here is what I have found useful when I want to think of science, but I do not say that you have to think of it the same way.
Firstly, science could be split into two different things. Those two have a lot to do with each other, but it is useful to separate them.
The first part is what I call the formal disciplines. They are such things as maths, philosophy, logic and so on. Some people say that they are science, some say they are separate. It does not matter which you do, as long as you keep your thoughts clear about which is which and what you mean by each when you speak of science.
The formal disciplines are called that because you base your arguments on the form of what you say. For example, we have shown that if we can say
A^2 = B^2 + C^2
then if we have a triangle with sides A, B, and C, then angle a is a right angle.
We do not have to measure it to prove it, nor even to know the values A, B, and C.; it is enough to know that we can say something of the form A^2 = B^2 + C^2. Formal disciplines do not have to have anything to do with reality to be true, only with the form of the thoughts they deal with.
The other part of science also has many names, but let's call it "Empirical science", the science of the things we can find out about the world around us.
No amount of work in the formal disciplines will prove anything about the empirical world; it always is necessary to check the empirical world empirically, looking at the "real world", as far as we are able, to see whether our ideas might not be wrong. This is how formal disciplines and empirical studies differ. In the formal disciplines you study the form, in the other, you study how well your ideas match the real world.
There is another thing about science: nothing that anyone says is proof of truth.
All the world's greatest experts could agree on something, but if you do not agree with them, you do not have to accept what they say.
All they can do in science is to say to you: "This is what we think, that is why we think so. If you do not agree, then try it yourself. If what you find is what we say, then you need to think very hard about whether you still do not agree. If what you find conflicts with what we say, then tell us about it and we will see whether we need to think and experiment again."
This is how science differs from religion. In all religions there are what we call tenets, doctrine, dogma; things that you must believe if you are to be a member of the faith. In science this is not so.
Science as a set of disciplines also is the most powerful means of discovering probable truths or approximations to truths and forms in the world as we see it. Nothing else in the history of the world has rivalled science in this respect.
Roughly speaking, we begin with a set of ideas of how things might be, then we think of a way to see whether there is anything wrong with our ideas, and in particular, which ideas seem to stand up to testing. Those ideas that do not, we can forget, which narrows down the number if ideas that we need to go on testing.
In following these principles we are working on a very important principle. A true thing can imply only other true things. A false thing can imply anything, true or false (I will not at this point discuss meaningless things.)
It follows that if an idea implies anything that we can see to be false, it is pretty good evidence that the idea itself is wrong.
OK, let us know whether you follow that, and whether you agree. Then we can see whether to go on with questions.
Cheers,
Jon
