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Anti-Gravity Theorys (The Floaty Kind) (Thread)

Hello!

I'm trying to figure out a number of A-G theorys for no particular reason. They don't have to be physically possible, just theoretically.

Here's Mine.

Gravity is created in space by large masses. So logically speaking, if we were so somehow suspend an object of the exact mass of the earth around 30 feet abov it, (it doesn't have to be 30 feet) inbetween earth and the weird chunk of floating mass, there would be no gravity. Of corse this would be impossible, because we wouldn't be able to get the mass there and suspend it, but the theory still works.

A couple of problems I can see.

  1. Wouldn't the gravity of the 2 objects pull each other together? Similar to 2 magnets of identical size and strength?

  2. Assuming you were able to keep them from colliding though... the second problem with your theory is that you are assuming that by placing a large object of equal mass, and therefore gravity, near the Earth, you would actually be canceling out the gravity of both objects. However, this isn't the case. Instead... both objects would be pulling with equal strength from opposite directions, assuming you are standing between them. It would essentially be the interplanetary equivalent of 'The Rack' used as a torture device in medieval times.

Also there's a difference between large masses and an object with large mass.

For example... if you were able to take a teaspoon of a white dwarf.... it would weigh around 5 tons.

im gettign a deja-vu here. didnt someone post almost exactly the same before, got disproved multiple tiems, and had also almost the same thread-title? yes, there was. certsinly, at least unless my lifre up to now was just a dream fo the future...

@break - True, but it was actually a discussion on Newton's laws. Not what it would take to make junk float.

To make junk float, you don't need to do something as impossible as manually (theoretically) create an object (or point in space) with a mass equal to Earth. Also in that case, as @Fieyr mentioned: The two objects, Earth and the other one, would smash together (fall onto each other, basically), given they would have no velocities.

Now how they do it on the ISS: the ISS (or your junk) are going around Earth in a circular orbit. Circular acceleration, being directed outwards, so in the opposite direction of where Earth is pulling, actually nulls out the gravity of Earth. That's how you get that weightlessness up there.

Back to your big heavy objects, the moon orbits Earth and is quite heavy. That has the effect of the two objects influencing each other's orbit shapes (Moon actually pulls Earth a little bit). Speaking about that, that's where the tides come from. Water is more sensitive to outer gravity, and when moon is above one side of Earth, all the water gets pulled to that point a little bit, leaving some places and flooding other places.

I hope that helped!
Cheers

Actually, the idea of large objects in space as firm balls is wrong. You should view them as giant balls of goo. There is this thing called Roche limit and it's basically a boundary between two objects in space at which those two objects tear each other apart(or the bigger one tears apart the small one, you get the point). What it actually is, it's material from one object literally flowing to the other.

As a direct consequence, you can't put a mass comparable to Earth's that close to Earth because masses would flow towards each other like a melting icecream(just as @Dave described, only with lava and stone instead of water).

But let's assume that objects in space are perfectly firm and that you can actually do that. Well, since we didn't assume humans to be perfectly firm, it'd be a really funny show to watch, if you're into internal organs and stuff.

You seem to be missing the point of antigravity though. When you say 'antigravity', that doesn't mean creating a point in space where the sum of gravitational forces amounts to zero(there are many points in space where that is roughly true, every 2-body system has at least one such point between the bodies).

The point of antigravity is not simply nullifying gravity with another force, it's creating a repulsive version of gravity, however strange that sounds, in other words manipulating the gravitational field itself. The best way to figure that out is looking at electric fields as an example.

One of the basic things you know about electric fields is, there are positive ones, and there are negative ones. Positive and negative fields cancel each other out. But we don't know about a field opposite of gravitational fields, it has never been measured, indirectly observed or noticed in any other way. So we're kinda stuck because we've never really seen a "positive"(repelling) gravitational effect.

Cool, I got referenced in this thread haha.
This thought I have probably doesn't fit in this thread but I read about a theory of creating an invisible dome over a city. They said if no light got through the dome than the place virtually doesn't exist. So could this be applied by negating the space by having light bounce off of something between Earth and the object create a space between each?

I think I may have gotten the whole thing wrong though. It was just a thought.

@JoJoBird

Your invisibility theory is interesting. It makes sense, but unfortunatly a material of such abilities doesn't exist (unless you know of one such material, in which case, please enlighten me) so its impossible. Bye!

Well, the non-existence you speak of is not the absence of space itself(and it's contents ofc). It is a reference to the quantum wave-particle duality wherein something is a wave(non-existent, undefined, probabilistic) until you hit it with a photon(observe it). Once measured, it manifests as a particle, but still not completely defined(see Heisenberg's principle).

So according to today's understanding of phyisics, just sealing light off from a certain space won't phase that space out of existance, it will just make it undetermined on a quantum level(not like we'd notice anyway though).
For more on this, see Schrödinger's cat.

If we could make earth spin fast enough and keep that exact speed we should be able to get zero gravity. Or am I wrong?

@Markov

The force pulling a thing A towards a thing B is reciprocal to the square of their distances. If you have two big objects (Like, most commonly, a planet and a moon or a sun and a planet) then there are exactly five points where their gravitational pulls cancel out. These points are called the Lagrangian points.

They're a popular place to place sattelites in, because these can stay there without much effort. If I recall correctly, ESAs Planck probe is sitting in one of the earth-sun lagrangian points.

@Noodle

Why,yes. That would work.

@halcy

Hm. Thats interesting. It make a lot of sence too.

@tokoyami I see, so if we made a photon resistant material of sorts so that it can not be observed than it could cause the object to float over the space which is covered by the material? I think the way I am thinking of this is putting a ball on a box and making the box nonexistent with the material than the ball would stay up, but then I don't think that's Anti-Gravity.
If its undetermined in a quantum level could it be whatever we please it,since it's not directly observed? Such as shrodinger's cat, I say its dead you say its alive, I say there's space you say there isn't.

@JoJoBird

Photons are not required for "observing". "Observing" is just going from quantum mechanics to classical physics. Even if you made a material that pefectly bends light around an object, the object would still be there. (The ball not falling through the box is, for example, also interaction, on a macroscopic scale, so that is also observation)

The field of Acoustic Levitation could possibly be the answer. Scientists have already been successful in suspending small creatures in a confined space using ultrasonic waves. For example, an emitter producing 20-millimeter-wavelength sounds can theoretically suspend an object with half that wavelength into zero-gravity. So if you figure out your own personal body's wavelength, you could double it to create anti-gravity for yourself. Now a possible complication with is that everyone has a different wavelength. Also, you would need quite the machinery to produce enough ultrasonic waves to levitate people. So I'd say it's theoretically possible. Maybe just not probable with our current science.

@Amander90

Oh god, thats cool!

If there is gravity, why does my ding-a-ling stick up?

@mizlily

Blood in your boner muscles.

@mizlily: It doesn't, that's against the laws of physics.

Also, if there are rules, why are you trolling a dead thread?

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