Third rock from the sun

Today I learned a little about helioseismology. I am definitely one of those people who is skeptical about things like "the sun is made up of X" unless I understand what the basis for the remark is. It was interesting to hear the answer, although I have no plans to learn any more about it.

Note: I also changed the list of other thing a day blogs to a blogroll. This should make it easy to see when they were last updated.