Comment by meindnoch

Comment by meindnoch 10 hours ago

2 replies

Sure, I'm not denying that entropy exists as a concept, that can be used to explain things macroscopically. But like you said, it's origins are statistical. To me, temperature is also a similar "made up" concept. We can only talk about temperature, because a sufficiently large group of particles will converge to a single-parameter distribution with their velocities. A single particle in isolation doesn't have a temperature.

So if they say gravity might be an entropic effect, does that mean that they assume there's something more fundamental "underneath" spacetime that - in the statistical limit - produces the emergent phenomenon of gravity? So it isn't the entropy of matter that they talk about, but the entropy of something else, like the grains of spacetime of whatever.

flufluflufluffy 8 hours ago

Yes, exactly. The model is based on (in the first approach) a “lattice” of some type of undiscovered particle-like thing (what they refer to as “qubits” in the article, which is unfortunate because it is NOT the same “qubit” from quantum computing) permeating space time. Or maybe more aptly, it is that lattice from which spacetime emerges. And what we observe as the force of gravity emerges from the entropic forces happening in this lattice.

spacecadet 9 hours ago

Im an idiot, let's get that out of the way first. I think that your temperature analogy answered your own question.

I guess my question in turn is, if we imagine a universe at the end of time(?), one that maybe dominated by a few black holes and not much else. Would an observer experience gravity if place sufficiently far enough way? Or even further, if nothing is left in the universe at all. Assuming that doesn't cause a big crunch, rip, or whatever...