The Meaning of Theory

This week's article covers the controversy over the word "theory" in science.

I've been asked to do a book review (Quantum Enigma), and I've been slogging it out trying to read the book through a vacation filled with far too many writing projects that I just *have* to get done. This week's column was actually inspired by a minor point covered in the book, the controversy of theory vs. law. This really isn't something that gets addressed all that often by scientists, and I'm glad the authors of the book decided to include it.

It's been hanging in the back of my head ever since, and has reminded me of an incident that happened to me when I was giving a guest lecture in a friend's physics class a couple of years ago. I was speaking on the history of unmanned spaceflight, and briefly mentioned the age of the solar system. Promptly, a woman in the middle of the class got up and yelled at me "That's not true! That's just a theory, that's not what it says in the Bible!" She was really livid, and left the class after another student yelled at her to sit down.

I was really stunned. I fully respect religious freedom, but I certainly wasn't sure how to handle a conflict like that. I know how to explain how scientists have figured out the age of the solar system, but it still contradicts what many people believe to be absolute fact. And that's the crux of the problem. Science isn't about the absolute fact, it's about the most probable fact. Most people desire their world view to be rooted in absolute certainty, not mostly certainty. Having the word "theory" after everything doesn't help much either, since most people interpret it as "hypothesis".

Personally, I like the mostly certainty world view. There's a comforting amount of wiggle room, and questions are welcome, even expected.