I can’t tell you how many times I’ve said (or thought to myself) “I swear I have a 25-hour internal clock” or “My internal clock is just behind everyone else’s.”

So of course when I saw a New York Times blog entry called “Sleeping (or Not) by the Wrong Clock,” I was compelled to read it.

It was written by Michael Terman, a professor of clinical psychology who directs the Center for Light Treatment and Biological Rhythms at Columbia University Medical Center, where they seem to be doing some pretty great research. I guess light therapy isn’t exactly a new idea, but they seem to be gradually refining their knowledge, the way scientists do.

The thing that was news to me is that one’s circadian rhythms aren’t necessarily permanent — the skillful and individualized application of light therapy can change them. I don’t know if I’m going to try that, but it’s interesting to know I could.