Just a Theory?

From reading a couple different posts, it seems like we may not have a good working definition of what a theory is. What is a theory and is it different in science from a theory on TV? IS Einstein's Theory of Relativity not as important or reliable because it is only a theory? What about the Theory of Evolution, do the same rules apply?

A short History of Nearly Everything

Welcome to AP Biology's summer reading forum. In this post, please feel free to ask any questions and make comments that you have for me or other students.
Questions that I have:
1) on page ten it states that in less than a minute that the universe is over million billion miles across. How can this be expanding faster than the speed of light? Do we just ignore Einstein's Theory of Relativity that nothing can travel faster than the speed of light?
2)On page 17 it states that we cannot find the center of the universe. If the universe is expanding at a set rate, don't you think that we would be able to trace it back to a center point, or at least close to it?
3)On page 25 it talks about the Oort cloud being the edge of our solar system. Does the Oort cloud orbit the sun, thus making it the edge of the solar system?
Please feel free to comment, keep it professional and let me know what questions you have as we progress through summer.