# Gravity through pressure

Pronoein
Hello, this is an incredible simple question but I couldn't find an answer by myself.

Is there a theory where gravity is a pressure and particles of matter low-pressure areas? (the pressure field could come from the overwhelming presence of a matter-repelling dark matter).

humanino
Dark matter does not repel, it also attracts, as anything with positive energy.

I am not sure it is an incredible simple question. Wheeler did formulate something equivalent to the idea contained in your question. For more details check the book "Gravitation" (a reference). -I don't remember exactly the page-

Phrak
Hello, this is an incredible simple question but I couldn't find an answer by myself.

Is there a theory where gravity is a pressure and particles of matter low-pressure areas? (the pressure field could come from the overwhelming presence of a matter-repelling dark matter).

Yes, but that doesn't make any such theory a serious contender.

Yes, but that doesn't make any such theory a serious contender.

Equation of state for vacuum: pressure + volumetric density of matter = 0. The only serious remaining question: does the vacuum gravitate? Since matter does... and since, in vacuum, volumetric density of matter and pressure seems to be the same (up to a minus sign) ...

S.Daedalus
Such models are generally grouped under the umbrella term 'http://en.wikipedia.org/wiki/LeSage_gravity" [Broken]', and are not considered a viable alternative to Newtonian gravity (not to mention being flat out inconsistent with general relativity).

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Such models are generally grouped under the umbrella term 'http://en.wikipedia.org/wiki/LeSage_gravity" [Broken]', and are not considered a viable alternative to Newtonian gravity (not to mention being flat out inconsistent with general relativity).

How do you then explain the observed acceleration (expansion) of our universe?

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Phrak
Such models are generally grouped under the umbrella term 'http://en.wikipedia.org/wiki/LeSage_gravity" [Broken]', and are not considered a viable alternative to Newtonian gravity (not to mention being flat out inconsistent with general relativity).

So it has a name and even a wiki page. I was wondering about that, thanks.

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Pronoein
I understand that the theory of gravity as a mechanical negative pressure would be more or less this way (in lay terms, sorry!):
1. There is a constant multidirectional shower of particles which creates a constant pressure.
2. Matter is opaque to these particles and create a multidirectional shadow.
3. Two overlapping shadows create a straight path of lowest pressure between the centers of the matter particles.
4. Particles of matter are then pushed towards and along these geodesics, and thus seem reciprocally attracted.

Pronoein
Equation of state for vacuum: pressure + volumetric density of matter = 0. The only serious remaining question: does the vacuum gravitate? Since matter does... and since, in vacuum, volumetric density of matter and pressure seems to be the same (up to a minus sign) ...
Are those facts true? Volumetric density of matter and pressure are in equilibrium in vacuum? Is it correct to say that in this case gravity is expressed as a negative pressure?

Staff Emeritus