If gravity seized to exist (Theory)

[TheNextTherory]

Well, aside from Quantum Physics changing, everything would fall apart, planets would stop spinning and orbiting.

 

Yea.

[ajb]

Stars would blow themselves apart.

[swansont]

Ceased to exist, perhaps?

[imatfaal]

Well, aside from Quantum Physics changing, everything would fall apart, planets would stop spinning and orbiting.

 

Yea.

"planets would stop spinning" No - conservation of angular momentum would mean that the cloud of rock and dust that was once a planet would continue to spin.

[swansont]

Also, quantum physics is separate from gravity. We don't have a quantum theory of gravity, so although that would change, we don't have knowledge of what would be different.

[O'Nero Samuel]

Isn't this speculation? I thought there was a section for this.

[swansont]

Isn't this speculation? I thought there was a section for this.

 

This is a question of physics, currently. Up until the OP insists s/he is correct about things that contradict standard physics. Then it's speculation.

[zapatos]

I would think that planets would stop spinning due to the fact that they would fly apart into many pieces due to gravity no longer holding them together. If a planet is not solid then wouldn't it quickly disintegrate in the absence of gravity?

[Strange]

I would think that planets would stop spinning due to the fact that they would fly apart into many pieces due to gravity no longer holding them together. If a planet is not solid then wouldn't it quickly disintegrate in the absence of gravity?

 

But it would carry on spinning, as it flew apart.

[Acme]

Sooooo... since gravity won't seize this is all rather a load of stuff that doesn't hang together and belongs in the won't-hang-together section.

 

Nevertheless, if gravity suddenly ceased to seize with everything as it is, then I agree with the OP about everything coming apart. Not 'falling' apart as stated however on account of things only fall because of gravity. I disagree that planets would stop spinning or that stars would explode however. Seems to me they would simply start to fly apart. Stars wouldn't explode because explosions require not just combustion but containment for pressure to build. No gravity, no containing pressure and the star would just sort of dissolve in flammage as the rotational momemtum spews the bits out. Planets would similarly dissolve sans flammage. Bits would collide of course as their trajectories intersect and depending on the velocities of the bits they could make like meteors and burn or just carom off in other directions. After some suitable time the universe would be a more-or-less homogenous dust doink behaving more-or-less like a gas gonk. (note that 'doinks' & 'gonks' are technical terms that apply only to ceased-to-seize gravigoverses.)

[Robittybob1]

Sooooo... since gravity won't seize this is all rather a load of stuff that doesn't hang together and belongs in the won't-hang-together section.

 

Nevertheless, if gravity suddenly ceased to seize with everything as it is, then I agree with the OP about everything coming apart. Not 'falling' apart as stated however on account of things only fall because of gravity. I disagree that planets would stop spinning or that stars would explode however. Seems to me they would simply start to fly apart. Stars wouldn't explode because explosions require not just combustion but containment for pressure to build. No gravity, no containing pressure and the star would just sort of dissolve in flammage as the rotational momemtum spews the bits out. Planets would similarly dissolve sans flammage. Bits would collide of course as their trajectories intersect and depending on the velocities of the bits they could make like meteors and burn or just carom off in other directions. After some suitable time the universe would be a more-or-less homogenous dust doink behaving more-or-less like a gas gonk. (note that 'doinks' & 'gonks' are technical terms that apply only to ceased-to-seize gravigoverses.)

There are already huge compression forces inside stars and planets just waiting for the day that gravity seized to exist.

[Acme]

There are already huge compression forces inside stars and planets just waiting for the day that gravity seized to exist.

Which would cease the instant gravity did.

[Robittybob1]

Which would cease the instant gravity did.

The rebound would be like an explosion.

[Acme]

The rebound would be like an explosion.

Yeah sure; whatever you say.

[zapatos]

But it would carry on spinning, as it flew apart.

How would a planet keep on spinning as it flew apart? My Honda would fly off the earth tangentially to the rotation, quickly followed by everything else. All the pieces would be moving in a straight line.

Unless you mean it would spin for the seconds (or whatever) until the roof over my head flew away before I could fly away.

[Robittybob1]

Yeah sure; whatever you say.

No you might be right, the rebound would take energy so it would take time.

Energy is released when there is gravitational compression so I believe heat would be required to reverse that too? Am I right?

Edited December 31, 2014 by Robittybob1

[elfmotat]

This is a question of physics, currently. Up until the OP insists s/he is correct about things that contradict standard physics. Then it's speculation.

 

It does seem a bit speculative. As I read it the question seems to be about what would happen if gravity were suddenly "turned off." I'm not sure that's even a reasonable physical question to ask. For example, what would happen to black holes? I think situations which clearly violate known physics qualify as speculative.

[ajb]

I'm not sure that's even a reasonable physical question to ask.

It is not a reasonable question as such, but such questions can be useful in understanding the role of gravity in various phenomena. Questions like this can be an aid to learning and should remain in the physics section. (In my opinion)

 

 

Back to the question... as imatfaal states, even without gravity we would still have angular momentum to take care of.

[Strange]

 

If gravity seized to exist

 

Gravity exists to seize.

[imatfaal]

How would a planet keep on spinning as it flew apart? My Honda would fly off the earth tangentially to the rotation, quickly followed by everything else. All the pieces would be moving in a straight line.

Unless you mean it would spin for the seconds (or whatever) until the roof over my head flew away before I could fly away.

I confess I cannot visualize such a situation - but we believe the conservation laws/symmetries of nature are fundamental and not tied to the action of any of the four forces; linear and angular momentum would be conserved.

 

It is only a toy theory that allows us to probe our intuitions and understanding - and to that extent it has worked as it is making me, at least, revisit what I think I know about angular momentum.

 

The planets would shatter - but some of the bits would be massive as there would be no external force of any significance acting on them; however as they are spinning the molecular and physical bonds of the planet will not be enough to keep hold of the outer portions which will break off.

 

The stars are bombs waiting to go off - the pressures inside are already immense and without gravity to counter this then the stars will explode. Not sure if this is a correct intuition but here goes; at equilibrium the pressure caused by the heat is balanced by gravity. When this balance is disrupted by a cooling when fuel runs short the gravity wins and the collapse is enough to trigger, eventually and in only some circumstances, a super nova. I see no reason that the opposite would not occur if hte gravitational side of the balance was removed - if gravity balances heat, but without heat you get a nova, I would guess that without gravity you would get a similarly destructive force. And the nova formation is slow compared to a sudden removal of gravity.

[michel123456]

Is this question related to the G and g constants getting to zero?

[imatfaal]

Is this question related to the G and g constants getting to zero?

I think it is more imaginary than that - although setting G to zero would be closest. g is not a constant - it varies depending on where you are.

[michel123456]

I remember a thread about objects in space under no gravity that kept holding together (like water) but that was not because of their own gravitational attraction.

Have to dig a bit.

-------------------

Cannot find it.

 

But IIRC it was said that molecular bindings are the forces that hold things together.

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Found this, not the thread i was talking about but anyway

 

http://www.scienceforums.net/topic/13935-whats-holds-matter-together/

[swansont]

I remember a thread about objects in space under no gravity that kept holding together (like water) but that was not because of their own gravitational attraction.

Have to dig a bit.

-------------------

Cannot find it.

 

But IIRC it was said that molecular bindings are the forces that hold things together.

--------------------

Found this, not the thread i was talking about but anyway

 

http://www.scienceforums.net/topic/13935-whats-holds-matter-together/

 

Rocks would be an example. Asteroids up to a certain size.

[michel123456]

So when G becomes null, in this equation

 

[latex]T=\frac{T_o}{\sqrt{1-\frac {2GM}{Rc^2}}}[/latex]

 

we have

 

[latex]T={T_o}[/latex]

Edited January 1, 2015 by michel123456