7 ms·
If the simulation was quantized, say like using integers of a large enough size to encompass all things in your simulation, it would be fully reversible I belie
by beiller 8y ago
If the simulation was quantized, say like using integers of a large enough size to encompass all things in your simulation, it would be fully reversible I believe. Of course I'm speaking from my limited understanding of physics engines in computers today like bullet or equivalent. Isn't floating point just like a compression for large numbers in limited bits, and the only reason it would not be reversible? The other potential non-reversibility is the fact that the physics engine uses some sort of integration like adding up forces at each time step unlike the universe which I believe is instant. (verlet integration? Google says that is reversible.)
- strainer 8y agoI do see floating point as like automatically compressed integers, but unlike simulations such as, Conway's game of life, the operations in a physics simulation produce real number values even if we begin with integer state, due to square roots and divisions mainly. I think whatever strength of integer or floated precision used to store results, it will never be possible to tell whether a certain parameter was eg. 328480284374964325 or 328480284374964326. And we need to be able to tell exactly what the input state for any output state must be, in order to have reversibility.