Do heavy things fall faster?

A child on a garden stool has just let go of a hammer and a feather: the hammer streaks down near the grass while the feather still floats high up on little puffs of air.

Drop a hammer and a feather — the hammer slams down first, every time. But astronauts say on the Moon they land together. Something is hiding the real rule.

First: gravity. It grabs every falling thing and won't let go — the longer it falls, the faster it goes. Tap to drop a rock.

tap to drop the rock

Second: air. A falling thing has to shove the air out of its way — and the air shoves back. The feather's big fluffy shape catches LOTS of air. The hammer slices right through.

A wide feather drifts down onto a crowd of tiny air specks that push back up against its underside, while a dense hammer far below slices straight through with barely any air in its way.

Now swap the hammer for a round ball. Race the ball and feather in a sealed tube. Slide the air away, tap drop, and watch who lands first.

air in the tube: full of air
no airfull of air

Try it with the air pumped all the way out.

Now the air is gone for good.

tiny marblegiant boulder

One dial left: how heavy the ball is. A tiny marble… or a giant boulder. Surely a super-heavy boulder finally beats the feather… 🤔

Same starting height. Same airless chamber.

Now drop a giant boulder next to the feather — does all that extra weight finally beat it?