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.

Do heavy things fall faster?

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.

Two identical airless tubes on the grass: in one a tiny marble waits at the top beside the feather, in the other a giant boulder waits beside the very same feather.

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

You just saw: no air, nothing holding the feather back.

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