[john_moscow]

Space exists around things with mass. Also, above-absolute-zero temperatures cause particles to jump around randomly.

Now if there is "more space" around particle A, particle B will have a slightly higher statistical chance of randomly jumping closer to it, than farther.

Rinse-repeat. Gravity as we know it.

[meindnoch]

>Also, above-absolute-zero temperatures cause particles to jump around randomly.

Does it? A single free particle won't "jump around randomly". Thermal motion is plain Newtonian motion with an extremely high rate of collisions. There's nothing random about it (let's put quantum things aside for now).

[AlexandrB]

This made me think of Norton's Dome[1] and how a particle would choose a direction to move when warmed from absolute zero to above absolute zero. Though I guess, "warming" in this context would mean a collision with another particle and that would determine the initial direction?

[1] https://en.wikipedia.org/wiki/Norton%27s_dome

[JPLeRouzic]

It sounds a bit like Le Sage's theory of gravity:

https://en.wikipedia.org/wiki/Georges-Louis_Le_Sage

[bravesoul2]

> particle B will have a slightly higher statistical chance of randomly jumping closer to it,

Why?

Also how do you explain acceleration due to gravity with that model. How do you explain solid objects?

[MaxikCZ]

My guess would be the answer is right in the part before you quote? If theres more "space" (imagining more space coordinates possible) for me on the left than on the right, me jumping to a random location would statistically move me left.

Repeating results in movement, getting closer to the object intensifies this effect, results in acceleration.

Solid objects are products of electric charge preventing atoms/particles from hitting each other, I dont think that has to have to do anything with gravity in this example?

[bravesoul2]

I don't understand the more space thing then. Is this more space due to spacetime curvature or something else.

E.g. if we have earth and moon:

    O   o

Why is there more space from the moon towards earth than away?

[jblezo]

Spacetime curvature.

Like if you dropped the earth on a giant sheet, it would stretch the sheet more than what the moon would have.

[bravesoul2]

If you rely on spacetime curvature for your explaination then why not just use general relativity to explain the gravity?

[strogonoff]

If space existed around things with mass, then what would you call the emptiness that replaces space the further you go away from things with mass?

[enriquto]

Sounds fun!

Would this imply that cold objects have weaker gravity?

[psittacus]

Isn't this something we already know from the mass–energy equivalence? In the same way that a nuclear reaction that produces heat must cost the object mass (and therefore gravitational pull)

[Quarrel]

It does, but because you have to divide the energy change by c^2, it is really really hard to detect it, and mostly overwhelmed by other effects of the heating/cooling.

[enriquto]

why do the units matter here? Under this theory, will a body at absolute zero have no observable mass? No attractive field around it, no inertia if you try to move it.

[Quarrel]

I'm only now seeing this a week later, but for E = mc^2, m is the rest mass.

rest mass = all the energies of the mass, not just its thermal energy. So, as it approaches 0 kelvin the thermal energy approaches 0 and the mass approaches its minimal possible energy (its kinetic energy approaches zero), but even at absolute zero, it still has the rest-mass of its fundamental particles (electrons, neutrons and protons) which have mass inherently. In practice, the scale of the mass of the particles massively outweighs the scale of the thermal mass, so while strictly true, it mostly doesn't matter.

So, because the scaling factor is stupid stupid large, changing temperature from anything to absolute zero does lower the mass, which does lower the gravity, but it just doesn't matter.

[Woansdei]

sounds more like the reverse to me, movement away from denser areas (less space), so like water leaking out of a container.