What if all the Earth’s land became ocean, and all the oceans became land? And what if our mountains turned into deep ...

Imagine never being able to dream of landing on Mars or traveling to Saturn. Not because it’s impossible to get there, but ...

Suppose you could speed up Earth’s rotation so that a day was only half as long? What would happen? Well, for starters we’d have to make new clocks that only have hours 1 to 6 for am and pm. If you ...

I will assume you’re referring to what would happen if Earth stopped rotating all at once, without any gradual reduction in velocity. In that event, most things on Earth would be almost immediately ...

Without the Moon, Earth’s geology, biology, and climate — as well as human philosophy — would be different in many significant ways. If Earth had no Moon, the postulated origin of the Moon through a ...