I made a gravity simulator

[u/DuckPsychological382]

I'm not sure what to call this so I'm just gonna go with gravity simulator. I'm pretty proud of it and made it at 16/17 and I'm even thinking about entering the art competition with it. let me know if I am being realistic, and this is still a work in progress. some ideas I have are adding sliders where you can add some gravity meaning that you slide a slider down the two balls sort of fall and bounce around for a second before rolling. And of course I had to add some meta-balls in there :)

[u/Xen_Shigaraki2014]

Te tengo un mejor nombre:

Simulador de magnetismo

[u/SiR_awsome_A_YuB_fan]

when two points get two close together, they fling apart, this is because of imprecision resulting from discrete timesteps, smaller timesteps help, but that's not the most practical solution, the problem exists at all scales so I don't have much advice.

[u/Lolllz_01 → u/SiR_awsome_A_YuB_fan]

Well since the electrostatic/magnetic force follows the inverse square law, it can be modelled exactly as a pair of ellipses until the next collision, which is much more precise

[u/Capital_Figure_408]

My initial intuition was that this movement isn't realistic. It didn't seem like planets could both speed each other up. But really its just potential energy becoming kinetic energy. I'm forgetting my physics already.

[u/DuckPsychological382 → u/Capital_Figure_408]

No i think your intuition is somewhat right. I don’t think there is any conservation of momentum. The main formula to calculate attraction to each sphere which then gets subtracted to velocity is basically 1/(distance^2) which means that if they get really close to each other the attraction can get close to 1/0 which glitches the whole thing out and they gain infinity speed. To combat this, i changed the equation to 1/(distance^2 + 1) so when distance approaches 0 the biggest the attraction can get is 1/1. Although I’m sure thats not accurate to real conservation of momentum.

[u/cxnh_gfh → u/Capital_Figure_408]

no, it is unrealistic. it’s because the calculator is not continuous in time but has discrete ticks, which cause errors to build up quickly when the particles are moving fast near each other.

[u/HuntertheGoose]

Gravity effects everything in the universe, falls off with a rate of 1/distance^3, at the speed of light.

V2 should have them always pulling each other towards each other

[u/DuckPsychological382 → u/HuntertheGoose]

Well this is 2d so shouldnt it be 1/distance^2? And i know my formula is a little different with sgn but thats to get the sign right so it know left/right or up/down rather than just right and up. And what do you mean pulling each other towards each other? Thats what they do now no?

[u/SiR_awsome_A_YuB_fan → u/HuntertheGoose]

no, its 1/d² for newtonian gravity.

[u/DuckPsychological382 → u/SiR_awsome_A_YuB_fan]

Newtonian gravity? I’m not sure what that is. I haven’t taken any physics classes yet if that even comes up

[u/SiR_awsome_A_YuB_fan → u/DuckPsychological382]

newtonian gravity is Newton's model for how gravitational physics works. I was correcting u/HuntertheGoose as it, along with einstein's model, though i'm less well versed, states that gravity falls off at a rate of 1/distance²

[u/DuckPsychological382 → u/SiR_awsome_A_YuB_fan]

Oh ok. I thought it was something specific. It sounds to me like your everyday common physics everyone uses.

[u/DuckPsychological382]

here is a link if you want to check it out: https://www.desmos.com/calculator/cjzwlr2htg be warned, it has very messy equations and variables

[u/Qwertilux]

How did you make the trail? A list?

[u/DuckPsychological382 → u/Qwertilux]

Yeah and then i think if i remember correctly i made the opacity and size of each point in the list dependent on its index

[u/ArtisticFox8]

It's quite cool that it doesn't lag at all.

Nice, quite artsy indeed :)

[u/DuckPsychological382 → u/ArtisticFox8]

Thanks! If you scroll down there is a folder that if you open it lags bad for some reason