If you drop a bowling ball and a feather in a vacuum, which hits the ground first?
Physics tells us they'll land at the exact same time. And now, thanks to the folks from BBC Two's Human Universe, we can see this demonstrated on a grand scale:
The show's host, physicist Brian Cox, carried out the experiment in the world's largest vacuum chamber — a 12-story tall cylinder operated by NASA in Ohio to test spacecrafts.
Even though most of us know the result of the experiment beforehand, it's still pretty cool to see it happen. There's something deeply counterintuitive about a feather falling as quickly as a bowling ball — which happens because, in the absence of air and other interfering factors, gravity acts on all objects in the exact same way.
Cox also carried out the experiment without the vacuum turned out, showing how air resistance messes with the results:
Watch the full video below: