Science’s Greatest Strength

One thing that sometimes comes up when we’re talking about Scientific Theories, is that Science changes. It isn’t static. Some of the science that I learned about in school is different from what I teach now. Science may be wrong. Some students think this is bad: “Why learn science if it changes? Why bother if it isn’t right?”. But this is actually Science’s greatest strength.

The confusion stems from a misunderstanding of what science really is. Science is about trying to find out the best explanation for how the natural world works. Think about that. It’s not how the world works, but really is our best current explanation for how it works. As we learn more, our explanations may change.

Once we thought that the Sun rotates around the Earth. It certainly looks that way. But if everything rotates around the Earth, then there are some strange things in the sky that have to be explained. The planet’s retrograde motion. Why Venus has distinct phases, but Jupiter doesn’t. These can’t be explained by having the Earth in the center. But long ago it was the best explanation we had.

Later on, Copernicus and Kepler came up with better explanations. The Earth isn’t in the center, the Sun is. The Earth is just a regular planet orbiting the Sun. This very neatly explains retrograde motion and Venus’s phases.

But it wasn’t quite right. Careful observation showed that something was funny with Mercury’s orbit. It wasn’t quite where Newtonian Mechanics expected it to be. Clearly, something was wrong with our understanding.

Albert Einstein’s Theory of Relativity explained the change in Mercury’s orbit. Mercury is so close to the Sun’s gravity that there are relativistic effects on its orbit.

So as our understanding increased, our explanations got better. The scientific theories changed. Science doesn’t change because it’s wrong, it changes because it improves. What was wrong was our understanding at the time. But at the time it was the best explanation we had. What you learn now is our best current explanation. If it changes in the future, it will be because we learn more, which is a Very Good Thing.