Some of us have been to those amusement park/carnival/theme park rides where you enter some capsule/machine, and you will float, etc.

There is also some other thing where you go inside a big room with normal gravity, and you are closed in and you start to float (i.e. no gravity), and the amount of gravity can be toggled by a person outside the room, or by some dial/switch, etc. It is like the picture I placed below.

enter image description here

I do not know what those things are called, and I will update accordingly when the names are presented, but what I am asking is how does that work?

How can the pull of gravity, result of the spacetime continuum affecting all bodies of mass, be artificially changed? If so, why don't we just alter gravity everywhere with these tools, and move giant, heavy objects easier and such?

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    $\begingroup$ These things exist?? Tell me where, so I know where I'm planning my next vacation! $\endgroup$ – Tristan Nov 19 '13 at 21:02
  • $\begingroup$ Gravity can appear to have reduced if (a) you have reduced / no normal reaction with the ground (b) you're acceleration points downwards (like just before an elevator stops from upward motion). Obviously, these effects can only be made to last a limited time. $\endgroup$ – Pranav Hosangadi Nov 19 '13 at 21:07
  • $\begingroup$ Maybe you mean using pressured air? $\endgroup$ – jinawee Nov 19 '13 at 21:12
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    $\begingroup$ The picture above is not 'going in a big room and flipping a switch'. It's inside of an airplane in near free-fall. $\endgroup$ – Brandon Enright Nov 19 '13 at 22:00
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    $\begingroup$ That's the vomit comet $\endgroup$ – Pranav Hosangadi Nov 19 '13 at 22:10

The only way to do it is to put you temporarily in free fall.

But as for the room you describe, I can only think of one type. Bring a scale with you next time you go down an elevator, and watch artificial gravity reduction at work! Heh heh.

  • $\begingroup$ Or to accelerate downwards $\endgroup$ – Pranav Hosangadi Nov 19 '13 at 21:13
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    $\begingroup$ Or spin you to the point you're pinned against a wall. A strong horizontal force can affect your perception of the force of gravity. $\endgroup$ – Brandon Enright Nov 19 '13 at 21:27
  • $\begingroup$ Check the picture in my post's body now (updated) of NASA's room. $\endgroup$ – Captain Plaster Nov 19 '13 at 21:52
  • $\begingroup$ A very strong magnetic field will also be able to levitate you, for example they have been able to levitate a small frog. $\endgroup$ – fibonatic Nov 19 '13 at 23:18
  • $\begingroup$ @fibonatic levitating a small frog is one thing, levitating a 100kg mammal is another. The frog needed a 10 tesla continuous field, which is right up at the sharp edge of research and deep into the spectacularly dangerous zone. $\endgroup$ – paul Jul 2 '15 at 2:32

I've never been at a theme park where you can mount into a plane at free fall.

The photo that you posted is inside a reduced gravity aircraft.

enter image description here

So you don't modify gravity, you are just falling.

  • $\begingroup$ Thanks! Didn't know that ... there is a ride I have been on where you get "sucked", but it's not free fall. $\endgroup$ – Captain Plaster Nov 19 '13 at 22:50
  • $\begingroup$ @CaptainPlaster You can consider upvoting/accepting the answer if it has helped you. $\endgroup$ – jinawee Nov 19 '13 at 23:03

It is because general theory of relativity. As it says, one person is in a lift suddenly someone cut the cable, then he will experience no gravity as both the lift and person are falling at same rate.

  • $\begingroup$ The equivalence principle is the appropriate title you're looking for. $\endgroup$ – Kyle Kanos Aug 3 '15 at 16:48
  • $\begingroup$ The person in the falling lift is "experiencing" just as much gravity as a person standing on the ground. They are just experiencing it in different ways. The person standing on the ground is experiencing gravity plus the normal force (i.e., the ground pushing back). The person in the freely falling elevator car is temporarily experiencing gravity without the normal force. $\endgroup$ – Solomon Slow Aug 3 '15 at 17:43

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