The Uncertainty Principle

Knowledge is finite. Heisenberg's uncertainty principle says, among other things, that by learning about one object, we cloud our knowledge of another. For example, if we want to know the position and momentum of an object, figuring one out will make our ability to determine the other less accurate. (Once I learn how to insert a hyperlink, like Bill and Andrew, I'll do that. Until then, here's the link: http://en.wikipedia.org/wiki/Uncertainty_principle).

The principle also states that by looking an object, we change it. If you want to see where an atom is located, you shine a flashlight on it. But the light will excite the atom and make it move around, so you can't get an accurate reading. (This would also with with a coffee mug, but you'd need a lot of light to make a discernable difference in the coffee mug). Instead of merely saying that all we need are better instruments, the principle stands for the idea that we can never know everything. There is a limit to knowledge.

This idea was controversial when it came out. Einstein, while agreeing to its basic assumptions, did not accept it, famously stating, "I cannot believe that God would choose to play dice with the universe." Bohr, a scientist who favored the idea, responded, "Einstein, don't tell God what to do." The principle is now greatly accepted.

How does this scientific principle impact your daily life? It doesn't. How often are you going to need to know exactly where an atom is? But as a theory, as an idea in the evolution of human thought, its groundbreaking. Only by accepting what we cannot know can we truly understand what we can know.