281–290 of 378 posts
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Unless the resolution of the rational model is fine enough to be indistinguishable from the continuous solution.
That would be very fine indeed since the CMB doesn't eg seem to be pixelated and we don't observe numeric instability anywhere.
Out of curiosity, what's the quantum angle limit? If position is quantized and all fundamental particle are isotropic, there must be a minimum "angle of turn" for all objects, and by extension, a "maximum angular accuracy" for something like, say, orienting the face of a macroscopic object to face a particular direction. How many of those fit in a circle?
while I also don't really think that angles are discrete, angular momentum *is* discrete, coming in multiples of hbar, the reduced Plank constant.
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If gravity is not quantized, would that not mean that it has infinite information (the accuracy to represent its values to infinite digits of precision), and thus cause a black hole due to such high information density?
IIUC, quantized doesn't mean finite, it just means discrete. Energy being quantized in bound states in quantum mechanics means that the eigenvalues are discrete, but a state can still be any linear combination whatsoever of the eigenstates. And since spacetime is continuous, it's determines by its values on a dense subset, in particular a countable sense subset, which would make both sets of possibilities, gravity an…
If you have a carbon atom, does it have unlimited information because it theoretically could instead have been some other number of atoms?
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Keep in mind in GR singularities don't really make sense either: i.e. when you pass the event horizon of a black hole, under GR the rules say that you must always been traveling towards the singularity. But the corollary of this is that it's not actually possible - mathematically - to arrive at the singularity (because then you'd be moving parallel with it rather then towards it). So while we can define what happens…
Can they reach the center? And how long would that take? I ask because time will slow down for them as they accelerate towards the center.
Which would imply that singularity isn't a singularity - i.e. the "hole" it makes would in fact be highly curved spacetime in one dimension, but completely flat in another (i.e. it would be a cylinder).
Which creates a hole lot of weird infinities in the system: i.e. a black hole becomes a finite bounded volume on the outside, but contains an infinite amount of space on the inside (since no matter how much you distort spacetime, the molecules of whatever falls in can just pull themselves together more tightly provided the distortion doesn't happen too quickly).
At the same time, we know that a basic semiclassical + Everettian model of the world does not correctly model reality - if we run a quantum-linked cavendish experiment, we don’t observe the gravitational effects of superposition. I.e. each branch of a quantum superposition behaves as if it is in its own spacetime. We can even run a Bell experiment linked to gravitational detectors and observe that the results are consistent with gravity being quantized.
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What would such an experiment look like? If it makes it easier, perhaps an experiment that's even harder (or much, much harder) to realize but easier to explain.
It's pretty simple. You basically have two suspended mirrors on wires and you shoot lasers at each mirror. Due to gravity there will be an interaction between the mirrors. There are then two things you can probe. First, the correlation between the two reflected lasers, and if you can achieve the extreme temperature requirements, entanglement between the two reflected lasers caused by the gravity. Now, the former does…
Somewhat off topic, and somewhat related: I don't think there actually is such a particle as a graviton. General relativity says that you can't tell the difference between being unaccelerated, and being in free fall. But in one case you have no gravitons coming in, and in the other you have gravitons. I can change whether gravitons are there or not by a (general) relativistic transformation. But that's not possible.…
I think this is a misunderstanding. Special relativity says you can't tell the difference between free fall (in a gravity well) and inertial acceleration with the example of a guy in an elevator typical here. Both cases have acceleration.
My question: does an accelerating elevator due to motors and pulleys curve spacetime too?
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Can you provide an example of a Lorentz boost that changes the number of particles?
It's pretty general. Just draw the worldlines for some particles bouncing off eachother, and then perform a Lorentz boost, which means choosing a new tilted spatial surface to intersect the worldlines. If you perform a boost, then the spatial surface intersect fewer or more worldlines, and worldlines which were for particles in one frame can become antiparticles in another. Consider an electron absorbing a photon at…
This isn’t saying physicist beta Moon will explode unleashing a kaiju.
Physicist cannot visualize what has yet to visualized. Blah blah blah. The primates are so full of themselves.
> It’s become dogma. All the other fields in nature are quantized. There’s a sense that there’s nothing special about gravity — it’s just a field like any other — and therefore we should quantize it. I keep on citing Stephen Hawking here on HN, but it again seems very appropriate: > It would be rather boring if this were the case. Gravity would be just like any other field. But I believe it is distinctively different…