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Author Topic: Where would everything fall if gravity were removed?  (Read 2912 times)

Naseem

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Naseem asked the Naked Scientists:
   
Where would all the celestial bodies actually fall if gravity is removed?

What do you think?
« Last Edit: 12/01/2011 09:30:02 by _system »


 

Offline QuantumClue

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Where would everything fall if gravity were removed?
« Reply #1 on: 12/01/2011 09:38:42 »
Would candy still taste sweet if all the sugar was removed?

Not the best of questions. But hopefully a rhetorical one at best. Of course candy would not taste sweet without sugar, and equally we would not free fall if gravity was not present.
 

Offline Soul Surfer

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Where would everything fall if gravity were removed?
« Reply #2 on: 12/01/2011 13:01:39 »
The simple answer to this question is that most of them would fall apart or even explode quite violently.  All stars are supported by gas pressure opposing the gravity that holds them together so in effect all the stars in the universe would go supernova simultaneously.  Quite spectacular! the similar would be true for gas giant planets  Rocky planets would probably hold together as long as the centrifugal forces associated with their rotation did not overwhelm the tensile strength of the materials that make them up.  my guess is that the earth would probably fly apart in a few large lumps.  of course everyone and everything not attached to the earth would fly off the earth quite quickly in a southerly direction (in the northern hemisphere) at an angle to the vertical equal to their latitude unless they were standing by the north pole.  That of course includes the ocean and the fishes!

On the whole pretty disastrous but as gravity is the main force that drives the universe on the large scale you would not expect much else.

 

Offline CliffordK

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Where would everything fall if gravity were removed?
« Reply #3 on: 12/01/2011 13:17:13 »
Actually,

If you are standing on the surface of earth, you would be flung out at a tangent to the planet (centrifugal force) from the rotation. 

Water certainly would also be flung away...  and eventually dissociate.  Solids wouldn't necessarily dissociate, but you're right that there is pressure and compression deep in the earth due to gravity, and loosing the gravity, it would tend to relax.  At least large fissures would open in the planet, if not as you say exploding.

The same would be true for the sun...  rapidly expanding to fill the entire solar system.
 

Offline yor_on

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Where would everything fall if gravity were removed?
« Reply #4 on: 14/01/2011 12:31:56 »
Without gravity you can't have a space. 'Gravity' makes space I think, and 'gravity' is matter. So without 'gravity' you shouldn't have any matter at all.

Why?

Turn it around, what happens to matter that is compressed?
It 'disappears' from our universe, becoming a singularity. The only thing left is the event horizon, like some sign post telling you that 'here was the last position where we saw that particular matter existing'.

so matter compressed drops out of the universe, having no place in 'Space' as its 'gravity' becomes 'infinite'. Gravity is as Newton saw it a 'force' placed at the center of all 'matter'. In relativity that is not the perfect truth as the bumps may be a little to the side, but it's still matter that creates the bumps, and the topology we have.
 

Offline yor_on

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Where would everything fall if gravity were removed?
« Reply #5 on: 14/01/2011 13:25:22 »
You might want to argue that energy make space, not matter. But to me energy is a relation, without matter there is no relation for energy to be defined from. As for a universe of light? Don't know, assume that all beams are parallel then they will not attract each other according to the Bonnor beam model.

And if so you will have no stress tension creating a space. If you assume them traveling in all directions they will attract each other on the other hand according to this model. What you might get if so would be a spot of infinite energy that just might be able to create particles?

Maybe?

And with that you would get 'frozen energy' aka matter,  creating 'space'?

maybe :)
==

We will have to assume virtual light for that one of course.
Otherwise I don't know what they should 'travel' in :)
« Last Edit: 14/01/2011 13:46:24 by yor_on »
 

Offline Bill S

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Where would everything fall if gravity were removed?
« Reply #6 on: 14/01/2011 22:53:30 »
Quote from: yr_on
It 'disappears' from our universe, becoming a singularity. The only thing left is the event horizon, like some sign post telling you that 'here was the last position where we saw that particular matter existing'.

If the matter 'disappears' from our universe, what maintains the event horizon?
 

Offline yor_on

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Where would everything fall if gravity were removed?
« Reply #7 on: 21/01/2011 15:16:15 »
Well, without matter I don't think there will be any 'SpaceTime' left? What a 'Event horizon' will interface against then I don't even want to guess :)

We see everything having a 'direction' towards a gravity well. But that builds on two 'objects' interfacing. SpaceTime and a singularity for example, with only a singularity left and the rest being something outside Plank scale the Singularity should be in the same position as we are now. Not having any 'outside' to speak of. The 'virtual world' seems to infuse SpaceTime, not caring for any boundaries we have to accept macroscopically. So that 'reality', if existing, have nothing to do with what we can observe. Assuming that a black hole in fact can represent a 'SpaceTime' of some sort between the EV and the singularity at its center it should experience the same phenomena. After all, we don't expect a Plank scale to disappear or shrink for the Spaceship infinitely close to light speed, so?
 

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Where would everything fall if gravity were removed?
« Reply #7 on: 21/01/2011 15:16:15 »

 

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