Astronomia

Astronomy fact or theory


It is extremely important to distinguish between facts and theories in science, and in every other subjectalso, because facts usually remain the same and theories often change. They are not always easy to differentiate, and even scientistsforget to do it. And the people who write science textbooks nearly always forget to do it. So I'll try to give you some guidelines so you cando it yourself, because twenty years from now the facts will be the same, but the theories may have changed a lot. I know because I've hadto relearn some theories since I taught this class 25 years ago, but the facts are the same. For example, the universe has doubled in agesince I was a boy, which gives you an idea of just how old I am. In this class, we will try to spend about 2/3 of the time on facts, so thatyou won't need to relearn the entire class when the theories change. Of course, we can't ignore the theories altogether, because they areour best explanations of the facts; it's just that we shouldn't consider them to be absolute truth. When some people see a scientific theorydisproven and replaced by another, they lose confidence in all of science, which is a big mistake. That is how science progresses and itis a wonderful way to learn about our world. So let's begin by reviewing the scientific method, to see just how facts and theories interact.