Fascinating. I wonder if something akin to this could happen for a brief moment on a molecular level if the universe were to undergo a "big crunch" scenario.
I can give it a try. It might work better if the pentagons don't form rigid clusters, though. Quite a while ago, I tried something like that with pentagons and lozenges, but the interaction was not as carefully designed, and the result was not convincing: ua-cam.com/video/UyFP7CCJXT8/v-deo.html
Nice! Do you also have plans on trying with graviational planet-forming, with the gravitational force coming from the particles only? That ought(???) to be similar to modifying the L-J potential to a "1-12" potential, right?
I hadn't thought of that, though some of my earlier aggregation videos could be seen as a first version of such a process. But I don't think it would be easy to get such a simulation to be stable without the help of a thermostat, which some might consider as cheating.
@@NilsBerglund Yeah you'd definitely need some mechanism to "radiate" energy out from the clump. In that sense a thermostat would be slightly odd - unless you can tweak it such that it reduces the total kinetic energy according to Stefan-Boltzmann's law, that sounds both fiddly and peculiar.
I can confirm, it is hard to get stable. Although I found it hard getting Runge Kutta 4 to run (I am not an experienced sim dev), it improved the situation a little. The problem really comes from numerical inprecission. Even in a really stable 4 particle system, it exploded after a few orbits, due to little imperfections accumulating
@@technikluke6561 The problem is more fundamental than that - the energy of the spread-out particles in their initial stage (mostly gravitational energy) are (or should be) conserved along their trajectories. So when they collapse towards their centre-of-mass the gravitational energy decreases (all particles closer to the centre-of-mass) and as a consequence the kinetic energy increases. Even if we have an ideal ODE-integrating scheme (symplectic would be at least a first step) that increase in kinetic energy would lead to a tricky state for the particles to merge - they would speed around at increasing speeds. 4th-order Runge-Kutta is not the best choice for integrating equations of motion, there are more robust systems, have a look at Størmer-Verlet schemes that are more robust over longer periods of time, and reversible.
Fascinating. I wonder if something akin to this could happen for a brief moment on a molecular level if the universe were to undergo a "big crunch" scenario.
can you apply high pressure to this material to see if it forms a “most stable” state?
I can give it a try. It might work better if the pentagons don't form rigid clusters, though.
Quite a while ago, I tried something like that with pentagons and lozenges, but the interaction was not as carefully designed, and the result was not convincing: ua-cam.com/video/UyFP7CCJXT8/v-deo.html
Nice! Do you also have plans on trying with graviational planet-forming, with the gravitational force coming from the particles only? That ought(???) to be similar to modifying the L-J potential to a "1-12" potential, right?
I hadn't thought of that, though some of my earlier aggregation videos could be seen as a first version of such a process. But I don't think it would be easy to get such a simulation to be stable without the help of a thermostat, which some might consider as cheating.
@@NilsBerglund Yeah you'd definitely need some mechanism to "radiate" energy out from the clump. In that sense a thermostat would be slightly odd - unless you can tweak it such that it reduces the total kinetic energy according to Stefan-Boltzmann's law, that sounds both fiddly and peculiar.
I can confirm, it is hard to get stable.
Although I found it hard getting Runge Kutta 4 to run (I am not an experienced sim dev), it improved the situation a little.
The problem really comes from numerical inprecission.
Even in a really stable 4 particle system, it exploded after a few orbits, due to little imperfections accumulating
@@technikluke6561 The problem is more fundamental than that - the energy of the spread-out particles in their initial stage (mostly gravitational energy) are (or should be) conserved along their trajectories. So when they collapse towards their centre-of-mass the gravitational energy decreases (all particles closer to the centre-of-mass) and as a consequence the kinetic energy increases. Even if we have an ideal ODE-integrating scheme (symplectic would be at least a first step) that increase in kinetic energy would lead to a tricky state for the particles to merge - they would speed around at increasing speeds.
4th-order Runge-Kutta is not the best choice for integrating equations of motion, there are more robust systems, have a look at Størmer-Verlet schemes that are more robust over longer periods of time, and reversible.