Our planet is constantly spinning. If you ever need to check this is true, just look and see the Sun as it changes position in the sky – the Sun is actually staying put and it’s us that’s moving! Earth is constantly spinning on its axis, completing a full rotation every 23 hours and 56 minutes. Amazingly, the inhabitants of Earth (us included) aren’t able to feel this spinning at all because everything around us (including the Earth’s atmosphere) is rotating too! If Earth ever suddenly slammed on the cosmic brakes, we’d know about it pretty quickly as the atmosphere would keep travelling at its original speed, wiping the surface of the planet clean in the process.
All this information makes the fact that Earth is slowing down a little worrying. But there’s no need to panic, the deceleration is only tiny, and that’s all thanks to the Moon and its pull on our tides. Roughly every 100 years, the day gets about 1.4 milliseconds (or 1.4 thousandths of a second) longer. No need to go changing your clocks just yet!