Though we sum up a day as 24 hours and a year as 365 days, Earth's rotational and orbital speeds aren't exactly consistent. Instead, both fluctuate, swayed by atmospheric drag, tidal forces, changes ...

Earth’s rotational speed is changing, and we’re more than partly responsible. A gigantic dam, our extraction of groundwater, melting ice sheets and rising sea levels are among the human-linked factors ...

When was the speed of earth's rotation first calculated? originally appeared on Quora: the place to gain and share knowledge, empowering people to learn from others and better understand the world.