I just heard about new theories proposed by Erik Verlinde about the fact that Gravity doesn't exist..or at least it's not a foundamental force. My question is : if this is true what are the implications on current models like string theory , eternal inflation ecc ecc ? what can change in the understanding of our universe ?

  • $\begingroup$ Semantics of the first sentence aside, I could read your question as asking if string theory admits models in which gravity is emergent in the sense of Verlinde. Is that it? $\endgroup$ – Nikolaj-K Sep 16 '13 at 14:25
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    $\begingroup$ For one, apples would stop falling. $\endgroup$ – Abhimanyu Pallavi Sudhir Sep 16 '13 at 14:28
  • $\begingroup$ @nick kidman yes exactly $\endgroup$ – Andrea Scaglioni Sep 16 '13 at 14:54
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    $\begingroup$ Essentially a duplicate of physics.stackexchange.com/q/4289/2451 $\endgroup$ – Qmechanic Sep 16 '13 at 15:23
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    $\begingroup$ For something like this, a link to a paper on arxiv would be really helpful. Otherwise how the heck are we going to know what is being discussed? AFAICT this is just a duplicate. $\endgroup$ – Ben Crowell Sep 16 '13 at 19:14

I take the question being asked to be:-

"If gravity doesn't exist, what are the implications ?"

Ergo, anything to do with Erik Verlinde is irrelevant to the question.

Gravity is one of the two infinite range forces; the other being the Coulomb force between electric charges.

Unlike electric charges, eg proton and electron, if they meet, effectively cancel as far as external fields are concerned. Like electric charges mutually repel, and can only be compressed together by Coulombic forces, outside of them; which in turn requires more outer charges.

Earnshaw's theorem tells us that no stable configuration of electric charges exists, so large amounts of matter cannot be compressed to high density by any static Coulomb field.

Gravity, is the only long range force that pulls instead of pushes (between like objects).

So gravity sucks. Without gravity there would be no stars; and no ground or apples to fall on it.

Doesn't matter a jot why gravity does or does not exist; without it there would be nothing that we would recognize.


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