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Author Topic: Is gravity down to curved spacetime, or gravitons?  (Read 2415 times)

Offline thedoc

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Mark Beardmore asked the Naked Scientists:
   
My question is about gravity. Einstein taught us that gravity is a warping of spacetime which causes objects to describe a curved path in the presence of matter. On the other hand, quantum mechanics tells us that gravity is communicated by tiny particles (gravitons) zipping backwards and forwards between two objects.
How can both be true? Please enlighten me.

Thank you for the wonderful podcasts you produce.

Mark Beardmore
Bristol, UK.
What do you think?
« Last Edit: 06/04/2014 23:30:01 by _system »


 

Offline zunimtn

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Re: Is gravity down to curved spacetime, or gravitons?
« Reply #1 on: 07/04/2014 01:05:29 »
My vote is for Einstein. 

The standard model is trying to present the gravitational force as a tossing of a graviton-medicine ball back and for between masses, which would just push them apart, right?  Just kidding, but...  Quantum theory remains unable, after great effort, to fit either of the players in the gravity-force into their quantum theory.

1)  It has to invent a Higgs field just to allow the standard model to account for the mass of particles.  Mass is supposedly intrinsic (not acquired.  something a particle is "born with").  Is anyone trying to invent a special field to give the electron it's charge?  No difference.

And 2) they are still unable to come up with how gravity can be achieved with gravitons. 

In other words, the standard model of quantum theory cannot currently account for any aspect of  mass/gravitational (spacetime) behavior.  And, relativity theory is just as accurate as quantum theory.  And Planck's unit of action is not an upward limit on the granulation of the universe.  It is a downward limit on the size of measurement that can be taken of its self-interactions.

That's my vote. 
 

Online jeffreyH

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Re: Is gravity down to curved spacetime, or gravitons?
« Reply #2 on: 07/04/2014 01:53:15 »
If you look at research on the two copy gluon nature of the graviton this may eventually resolve the situation in favour of the graviton.
 

Offline Pmb

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Re: Is gravity down to curved spacetime, or gravitons?
« Reply #3 on: 07/04/2014 03:14:57 »
Mark Beardmore asked the Naked Scientists:
   
My question is about gravity. Einstein taught us that gravity is a warping of spacetime which causes objects to describe a curved path in the presence of matter. On the other hand, quantum mechanics tells us that gravity is communicated by tiny particles (gravitons) zipping backwards and forwards between two objects.
How can both be true? Please enlighten me.

Thank you for the wonderful podcasts you produce.

Mark Beardmore
Bristol, UK.
What do you think?
They are both supposed to be right and looked at from different points of view. Einstein's general theory of relativity is a classical theory which describes the gravitational field whereas quantum theory describes the mechanism of gravity.

re - Einstein taught us that gravity is a warping of spacetime which causes objects to describe a curved path in the presence of matter. - That is a myth. Einstein never taught us that. That's a common misconception about Einstein. While it's true that spacetime is curved in regions of spacetime where there are tidal gradients, gravitational fields can also be present in flat spacetime. It's wrong to think of curved spacetime as a actually being synonymous with gravity.

So there's no problem with them both being right.  Einstein describes gravity with his field equations while quantum gravity describes the mechanism of the gravitational interaction.

 

Online jeffreyH

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Re: Is gravity down to curved spacetime, or gravitons?
« Reply #4 on: 07/04/2014 10:30:26 »
Mark Beardmore asked the Naked Scientists:
   
My question is about gravity. Einstein taught us that gravity is a warping of spacetime which causes objects to describe a curved path in the presence of matter. On the other hand, quantum mechanics tells us that gravity is communicated by tiny particles (gravitons) zipping backwards and forwards between two objects.
How can both be true? Please enlighten me.

Thank you for the wonderful podcasts you produce.

Mark Beardmore
Bristol, UK.
What do you think?
They are both supposed to be right and looked at from different points of view. Einstein's general theory of relativity is a classical theory which describes the gravitational field whereas quantum theory describes the mechanism of gravity.

re - Einstein taught us that gravity is a warping of spacetime which causes objects to describe a curved path in the presence of matter. - That is a myth. Einstein never taught us that. That's a common misconception about Einstein. While it's true that spacetime is curved in regions of spacetime where there are tidal gradients, gravitational fields can also be present in flat spacetime. It's wrong to think of curved spacetime as a actually being synonymous with gravity.

So there's no problem with them both being right.  Einstein describes gravity with his field equations while quantum gravity describes the mechanism of the gravitational interaction.

Hi Pete. I am so glad that you have made this post about the curvature issue. It is something repeated over and over again. BTW did you see the  work on the measurements of the vortex around the earth? I can't remember the website offhand. It used gyros on a satellite in orbit. This demonstrates the curvature element
 

Offline zunimtn

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Re: Is gravity down to curved spacetime, or gravitons?
« Reply #5 on: 07/04/2014 17:44:48 »
Thanks for the info on the two copy gluon thing.  I actually passed over an article on that, and have called it back up to read, so again, thanks.

And to PMB, I don't really picture "curved" spacetime.  I imagine spacetime as the field of gravitational gradients,  but who know, maybe the gluon similarity will go somewhere.

Thanks!
 

Online jeffreyH

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Re: Is gravity down to curved spacetime, or gravitons?
« Reply #6 on: 08/04/2014 00:36:16 »
Thanks for the info on the two copy gluon thing.  I actually passed over an article on that, and have called it back up to read, so again, thanks.

And to PMB, I don't really picture "curved" spacetime.  I imagine spacetime as the field of gravitational gradients,  but who know, maybe the gluon similarity will go somewhere.

Thanks!

I found this discussion topic which discusses some proposed implications. I have no idea how valid they are so read with caution.

http://forum.nasaspaceflight.com/index.php?topic=33838.0
 

Online jeffreyH

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Re: Is gravity down to curved spacetime, or gravitons?
« Reply #7 on: 08/04/2014 00:44:43 »
The weakness of diamagnetism and the strength of an induced magnetic field show some similarity to the difference between the strong nuclear force and the weak gravitational force. As the weak diamagnetic field is repelled by an induced field, could the strong nuclear force oppose the gravitational force? Gluons create an asymptotic freedom, whereas gravity seems to be exactly the opposite. The further away from the source the easier it is to move. The strong force has a stronger pull the further away the quark is. Does the diamagnetic field have a short range in the same way as the strong force does?
« Last Edit: 08/04/2014 01:09:20 by jeffreyH »
 

Online jeffreyH

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Re: Is gravity down to curved spacetime, or gravitons?
« Reply #8 on: 08/04/2014 00:54:50 »
Water is weakly diamagnetic. This site gives a simple explanation of the general properties of water for anyone interested.

http://www.dummies.com/how-to/content/the-unusual-properties-of-water-molecules.html

And some interesting videos here.

http://terpconnect.umd.edu/~wbreslyn/magnets/do-magnets-work-under-water.html

« Last Edit: 08/04/2014 01:08:18 by jeffreyH »
 

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Re: Is gravity down to curved spacetime, or gravitons?
« Reply #8 on: 08/04/2014 00:54:50 »

 

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