Brian Cox visits the world's biggest vacuum | Human Universe - BBC

This is Nasa's space power facility near Cleveland, Ohio, and it is the world's biggest vacuum chamber it's used to test spacecraft in the conditions of outer space and It does that by pumping out the 30 tons of air in this chamber until they're about 2 grams left This I've got an eccentric construction. Which is part of this history it was built in the 1960s as a nuclear test facility to test nuclear Propulsion systems and That meant that they built it out of our [mininum] to make the radiation

easier to deal with aluminium is not the best thing the strongest material to build a vacuum chamber out of so they built out a Concrete skin which is part radiation shielding and part an external pressure vessel so this thing can take The Force that's present on the outside when it's pumped out to the conditions of outer space Galileo's experiment was simple he took a heavy [object] and the light one And drop them at the same time to see which fell fastest Now in this case the feathers fell to

the ground at a slower rate [than] the bowling ball because of air resistance So in order to see the true nature of gravity we have to remove the air It takes three hours to pump out the 800 thousand cubic feet of air from the chamber We drop to millet or in the last 30 minutes, but once it's complete. There's a near-perfect vacuum inside 6104 Manual 10 percent [orbit] Station One go for [Drive] PCB 30-1 pressure set point at 240 PSI. We are go for drop and nine eight seven six five four camera

s on two one release Yeah, look at that. They came down exactly this Exactly, not gonna silent exactly just a feathers. Don't move nothing look at that. That's just brilliant Isaac Newton would say that the ball and the feather fall because there's a force pulling them down gravity What einstein imagined the scene very differently? The happiest thought of his life was this: the reason the bowling ball feather fall together is because they're not... ...falling They're standing still There is no f

orce acting on them at all He reasoned that if you couldn't see the back gravity There'd be no way of knowing that the ball and the feathers were being accelerated towards the Earth So he concluded: They weren't