Shorter Days

If there just aren’t enough hours in the day for you, think of this: Earth’s day is longer now than it used to be. A recent study found that 70 million years ago, it was a half-hour shorter than it is now. And as you go even farther into the past, the day gets even shorter.
That’s because the tides act like a brake. As they race around the planet, they slosh against the land and the seafloor. That exerts a “push” against the solid planet, causing it to spin a little slower. At the same time, the tides are causing Earth and the Moon to move farther apart — by an inch and a half per year.
Researchers recently used lasers to count the growth rings in the fossils of a type of clam. The study showed that near the end of the reign of the dinosaurs, Earth rotated 372 times a year. In other words, a year consisted of 372 days. The length of a year hasn’t changed, so that means the length of a day has — it’s gotten a half hour longer.
Earlier studies, which used ancient coral and other fossils