Earth is Losing Days, But They’re Getting Longer

It’s amazing what scientists can learn, from a clam. By studying the shell of a fossilized bi-valve from the Cretaceous-era, they discovered that days were 30 minutes shorter 70,000,000 years ago. Clams grow one layer a day, and develop rings like trees, that tell the conditions each year. They counted the layers per year, and found 372!