The older we get, the shorter everything feels, and that can really be quite distressing. Last year’s holiday season feels like yesterday, as does the futuristic-sounding year 2000, and that was almost 22 years ago. Even summer isn’t as long and relaxing as it was when we were young.
As much as we may want to escape time, we can’t, and more and more research suggests that time is somehow intrinsic to our bodies. There is, of course, our circadian rhythm—a natural internal clock that can maintain a 24-hour cycle even while stuck in a dark, empty room for months at a time. And every one of our cells can also tell its own time, so much so that some scientists even assembled a biological clock in a test tube to study how it works.