Gravity

A Bowling Ball And Feather Will Fall At The Same Rate In A Vacuum Chamber

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Next time you find yourself in a vacuum (we're not holding our breath for it), don't waste the opportunity to try out a classic science experiment. If you simultaneously drop a bowling ball and a feather from the same height in a vacuum, they will hit the ground at the same time. The result is just as much due to gravity as it is due to air resistance.

No, This Doesn't Defy Gravity

You know what will happen if you were to brush a feather off your desk onto the floor: a light, slow, airy fluttering to the ground. You also know what would happen if you pushed a bowling ball off the edge: a fast, heavy, loud kerplunk with the added bonus of broken floorboards. It would certainly be jarring if the light and heavy object fell at the same speed. But gravity doesn't work that way, right? Gravity does work that way (all objects fall towards the Earth at a speed of 9.8 m/s²)—you're just forgetting about the air. The feather floats to the ground because of all the air resistance slowing down the speed of its fall. Throw the feather and bowling ball off a ledge in a vacuum chamber that has had all the air pumped out of it, and you'll see what happens when there's no air resistance keeping the feather aloft—objects dropped at the same time from the same height will land at the same time too.

No Vacuum Chamber, No Problem

This experiment doesn't necessarily require a cumbersome vacuum chamber. Make like Apollo 15 astronaut David Scott and zip up to the moon to try it out. Scott famously recreated this experiment in 1971 on our lunar pal with a falcon feather and a hammer. What happened was no surprise (the feather and hammer hit the surface of the moon at the same time), but the live broadcast was still a sight to behold.

If you're interested in expanding your knowledge on gravity, check out "On Gravity: A Brief Tour of a Weighty Subject" by physicist A. Zee. We handpick reading recommendations we think you may like. If you choose to make a purchase, Curiosity will get a share of the sale.

Written by Curiosity Staff January 10, 2017

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