It feels obvious that heavy things fall faster than light ones, but drop a hammer and a feather where there is no air to slow them and they hit the ground at the exact same instant, the same result an astronaut proved by releasing both on the airless surface of the Moon.

Drop a hammer and a feather on Earth and the result seems obvious. The hammer hits the ground first. The feather drifts, turns, slows, and arrives later. The difference is easy to misread, because air is what makes the two falls look so different. On 2 August 1971, near the end of Apollo 15’s final [...] The post It feels obvious that heavy things fall faster than light ones, but drop a hammer and a feather where there is no air to slow them and they hit the ground at the exact same instant, the