Simulation of a 2B-atom cell that metabolizes and grows like a living cell

Re:Simulation of a 2B-atom cell that metabolizes and grows l... by dekhn on Friday January 28, 2022 @11:16AM (#30116588)

I doubt it makes sense to assume the unverise is continuous (I'm glad you said "seems"). In particular, space could be spatially quantized (say, around the planck length) or any number of other details.

People have done simulations with quad precision (very slow) but very few terms in molecular dynamics would benefit from that. In fact, most variables in MD can be single precision, exceptt for certain terms like the virial.

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Re:Simulation of a 2B-atom cell that metabolizes and grows l... by mensetmanusman on Friday January 28, 2022 @01:38PM (#30118608)

It’s definitely fun to think about.

If the universe is discrete, how does one voxel communicate to the neighboring voxel what to update without passage through ‘stuff in between’ that doesn’t exist? Heh

It seems physics is going the opposite way with infinite universes and multiple dimensions to smooth out this information transfer problem and make the discrete go away.

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Re:Simulation of a 2B-atom cell that metabolizes and grows l... by javajosh on Friday January 28, 2022 @02:05PM (#30118940)

As someone with keen interest in physics (and a bit of training) I find speculation about "discrete space" disquieting. It's the level of abstraction where intuition about space breaks down, and you have to be very careful. Remember that coordinate systems are short-hand for measurement. It's one thing to admit fundamental limits on measurement resolution, and quite another to say that space itself is quantized! Mostly I get around this by not thinking about it; most of these theories are only testable in atrocious and unattainable conditions, doing things like performing delicate QED experiments at the edge of a black hole.

I don't think your "voxel" intuition can be right because it's a small jump from that to (re)introducing an absolute reference frame.

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Re:Simulation of a 2B-atom cell that metabolizes and grows l... by joshmarlow on Friday January 28, 2022 @02:23PM (#30119151)

> how does one voxel communicate to the neighboring voxel what to update without passage through ‘stuff in between’ that doesn’t exist? Heh

That kind of reminds me of the 'aether' that was once hypothesized as a medium of transmission for light and radio waves [0].

Also, voxel's communicating sounds an awful lot like a higher-dimensioned cellular automata.

[0] - https://en.wikipedia.org/wiki/Aether_theories

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Re:Simulation of a 2B-atom cell that metabolizes and grows l... by Yajirobe on Friday January 28, 2022 @04:05PM (#30120364)

Stephen Wolfram was right all along

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Re:Simulation of a 2B-atom cell that metabolizes and grows l... by whatshisface on Friday January 28, 2022 @12:51PM (#30118012)

All of our current theories are set in continuous spacetime. At the present, there's no reason to assume anything else.

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Re:Simulation of a 2B-atom cell that metabolizes and grows l... by feoren on Friday January 28, 2022 @01:57PM (#30118854)

I wouldn't say that "all our current theories" are set in continuous spacetime. For example, Quantum chromodynamics is set in SU(3), an 8-dimensional group of rotation-like matrices. Electric charge is discrete, spin is discrete, electron orbitals are discrete. In fact position and momentum would seem to be the outlier if they were not also discrete. I hardly call that "no reason".

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Re:Simulation of a 2B-atom cell that metabolizes and grows l... by whatshisface on Friday January 28, 2022 @02:13PM (#30119026)

SU(3) is a continuous group.

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Re:Simulation of a 2B-atom cell that metabolizes and grows l... by freemint on Friday January 28, 2022 @04:20PM (#30120511)

Yeah but it is very much not in space time.

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Re:Simulation of a 2B-atom cell that metabolizes and grows l... by whatshisface on Friday January 28, 2022 @05:35PM (#30121404)

But it is. SU(3) is the group for swapping colors around. It still has spacetime.

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Re:Simulation of a 2B-atom cell that metabolizes and grows l... by freemint on Friday January 28, 2022 @05:37PM (#30121422)

You can Cartesian product it with space time, yes. But that is possible for any system.

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Re:Simulation of a 2B-atom cell that metabolizes and grows l... by whatshisface on Friday January 28, 2022 @06:24PM (#30121904)

I'm having a hard time imagining quantum chromodynamics set in a single point. :)

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Re:Simulation of a 2B-atom cell that metabolizes and grows l... by drdeca on Friday January 28, 2022 @04:54PM (#30120895)

It is based on SU(3), but, does it really make sense to say that it isn't still set in spacetime? Like, quarks still have position operators, yes?

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Re:Simulation of a 2B-atom cell that metabolizes and grows l... by jacquesm on Friday January 28, 2022 @01:13PM (#30118317)

True, but we do not actually know this for sure. There is a (small) possibility that we are simply looking at this at a scale where all we see is macro effects. It would require the quanta to be much smaller than the Planck distance though.

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Re:Simulation of a 2B-atom cell that metabolizes and grows l... by webmaven on Friday January 28, 2022 @02:19PM (#30119090)

> There is a (small) possibility that we are simply looking at this at a scale where all we see is macro effects. It would require the quanta to be much smaller than the Planck distance though.

How much smaller?

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Re:Simulation of a 2B-atom cell that metabolizes and grows l... by jacquesm on Friday January 28, 2022 @02:27PM (#30119194)

Many orders of magnitude. How many? I do not know, I don't think anybody does.

But photons resulting from the same event but with different energies arrive at detectors an appreciable distance away to all intents and purposes simultaneously, something that would not happen if spacetime were discrete at a level close to the Planck length. So it would have to be quite a big difference for an effect not to show up as a difference in time-of-flight.

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Re:Simulation of a 2B-atom cell that metabolizes and grows l... by aeternum on Sunday January 30, 2022 @05:51PM (#30142076)

Is the idea that the two photons would traverse slightly different voxels due to the lower frequency wave being more spread out?

What accounts for the expectation that they do not arrive simultaneously in a voxel-based universe?

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Re:Simulation of a 2B-atom cell that metabolizes and grows l... by dekhn on Friday January 28, 2022 @01:09PM (#30118277)

the issue is that there are no theories based on experimental evidence at very small scales. I agree that in most situations, it would be silly to violate this assumption, unless you were working on advanced physics experiments.

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