There’s a leap year every year that is divisible by four, except for years that are both divisible by 100 and not divisible by 400. It all has to do with how we count and the fact that the earth orbit is a little crooked. I want to wish everyone who was born on February 29th a very happy birthday. Having a birthday once every four years helps people stay young.
A leap year isn’t caused by the earth’s orbit being crooked. It is caused by the fact that the time it takes the earth to revolve around the sun (otherwise known as a year) is not exactly divisible by the time the earth takes to rotate on its axis (otherwise known as a day). We think of a year being 365 days but it is actually 365.2421 days. The leap day corrects for that extra 1/4 of a day. So maybe you should stick to real estate and give up on the dream of becoming an astronomer! 🙂
Thanks for the lesson.