Earth physically rotates in 23hours 56min relative to distant stars – a Sidereal Day, BUT it takes 24hours to rotate relative to the Sun – a Solar Day
The difference? Earth orbits the Sun, so the Sun appears to move (down, in the vid), which means Earth needs +4mins to catch up!
The difference? Earth orbits the Sun, so the Sun appears to move (down, in the vid), which means Earth needs +4mins to catch up!
NOTE this has absolutely nothing to do with the leap day / leap year!
Leap years are needed because Earth takes 365.24 days to orbit, and we keep short-cutting it by 0.24 days a year. After 4 years Earth is a day behind, and we give it +1 day to catch up in a February.
Leap years are needed because Earth takes 365.24 days to orbit, and we keep short-cutting it by 0.24 days a year. After 4 years Earth is a day behind, and we give it +1 day to catch up in a February.
BIG conclusion: there are 366 Earth rotations of Earth relative to the Stars per ordinary calendar year (i.e. per 365 solar-days).
So in 2019 for example, Earth rotated 366 times.
I'll be doing a leap day/year explainer next, so you can hit follow if you want to see that
So in 2019 for example, Earth rotated 366 times.
I'll be doing a leap day/year explainer next, so you can hit follow if you want to see that
If Earth did NOT orbit the Sun, then both Sidereal and Solar days would equal 23hr 56min. We wouldn't have a year at all, and would slowly be pulled into the Sun... which would be Unreal
Thanks very much for all your positive replies to this, looks like this really clicked with a lot of you (gained an unusually high number of new followers for this fairly non viral tweet)
