# grainy gravity

Discussion in 'Pseudoscience' started by nebel, Oct 13, 2015.

1. ### nebelValued Senior Member

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since mass is concentrated in relative small volumes like Protons in the small, and stars in the larger field,-- compared to the empty space separating them, should there not be a graininess to gravity even at the smallest level?

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3. ### originIn a democracy you deserve the leaders you elect.Valued Senior Member

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I wouldn't think so because the small particles do not have a small discrete 'sphere' of gravity. Particles have a gravitation that smoothly decreases by $\frac{1}{r^2}$.

5. ### YazataValued Senior Member

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I'm not a physicist, but it sounds plausible to my layman's ear.

Other forms of energy seem to be quantized on the microscale. And there's talk of gravitons, which seems to suggest quantization of gravity too.

So one might ask whether all physical quantities are quantized on the smallest scale. Might it be the case that no physical quantities increase continuously, but only through small discrete increments?

Maybe physical reality itself is grainy.

7. ### OnlyMeValued Senior Member

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I don't think so!

I know that it has been demonstrated that gravity affects single atoms, the same as it does larger objects.., and I believe the same has been experimentally demonstrated for neutrons... I just can't recall the reference for the neutron experiment.

That does not mean that gravitation is may not be quantifiable, just that any resulting graininess would have to be far finer than we could detect.

Also the graviton would essentially just be a specialized virtual photon. An analogue of the virtual photon force carriers of electromagnetism... We cannot detect, let alone measure virtual photons (or gravitons) so any graininess that might result would also be unmeasureable.

8. ### nebelValued Senior Member

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with the high density of these particles, the field although decreasing with the square of the distace would be quite steep near the particle, I see the problem with the velocities of all these sub atomic entities, how would you isolate a strong individual field in that broth?

9. ### originIn a democracy you deserve the leaders you elect.Valued Senior Member

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I don't think you can, that is why I don't think gravity is 'grainy'.

10. ### nebelValued Senior Member

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you are right, probably not grainy beyond the level of an atom.

11. ### danshawenValued Senior Member

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Only if there were a graininess to time or to time dilation, and there isn't.

12. ### nebelValued Senior Member

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my idea of the graininess of gravity was based on the smallness and density of the neutron, proton and the steep gravity around them in that empty space of the atom. to me time does not enter into gravity, it is there, even if you do not move through time. with enough gravity, you can appear to be stuck in zero time movement. or???
to me time is a continuum, through which we are moving, ever since the big bang beginning. not in increments.

Last edited: Oct 19, 2015
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13. ### danshawenValued Senior Member

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This kind of graininess is exactly what persuades some folks (Brian Greene in particular) that matter, space, time, and energy are all "grainy", and as such, can even be completely described by means of finite math. The preponderance of evidence is, they are not. Something about binding energy makes it grainy (quantum theory) with respect to further interactions with energy and with other bound energy, and I believe that graininess derives of a discontinuity between the speed of light in a vacuum and the speed of entanglement, but I understand this is not a mainstream view, nor is it part of a complete theory.

If gravity were "grainy", and if there were only two particles of near insignificant mass spaced light years apart and originally at rest with respect to each other, then gravity would not be able to act on them to pull them together, would it? Of all the fundamental forces, gravity is by far the weakest, so I doubt it could act as a force at all if it were "grainy". At least it is fair to say, the other forces are "grainier". EM derives mostly of electrons, protons, and photons, and all but photons are bound. Electroweak is really the same as EM and only happens within atoms, so also bound. Strong nuclear between mostly quarks and gluons are also bound.

Gravity isn't really a "bound" force until you ramp it up to the scale of a black hole, yet even photons (not grainy) are bent by it long before it reaches that extreme, and is capable of absorbing (but not re-emitting) photons. Unlike the corresponding quantum effects, black holes, with the exception of Hawking radiation, are not very selective about what photon energies they will absorb, either.

Last edited: Oct 19, 2015