Toy n-body simulation in Lua with an arbitrary number of spatial dimensions and basic special relativity adjustments.
lua nbodies.lua BODIES_FILE_PATH TIME_STEP TIME_END
BODIES_FILE_PATH is a path to a JSON file describing the starting state of the bodies to be simulated. See section below.
TIME_STEP is a floating-point value expressing the seconds between samples. Lower is more precise, but slower to compute.
TIME_END is the number of seconds at which to terminate the simulation.
$ lua nbody.lua bodies.json .1 10000
{
mass = 5.972e+24,
pos = {
[1] = 15929.242339019,
[2] = 0,
[3] = 138.58009194716,
}
vector = {
[1] = 3.1886978322112,
[2] = 0,
[3] = 0.041637309060105,
}
time = 10000.000000019,
name = 'Earth',
rest_mass = 5.972e+24,
}
{
mass = 7.3476730900009e+22,
pos = {
[1] = 391213312.08884,
[2] = 0,
[3] = 10218736.565999,
}
vector = {
[1] = -259.16917125614,
[2] = 0,
[3] = 1019.6158264438,
}
time = 10000.000000019,
name = 'Moon',
rest_mass = 7.34767309e+22,
}
Example of expected JSON:
[
{
"name": "Earth",
"mass": 5.972e24,
"pos": [0, 0, 0],
"vector": [0, 0, 0]
},
{
"name": "Moon",
"mass": 7.34767309e22,
"pos": [392508000, 0, 0],
"vector": [0, 0, 1023]
}
]
Masses are in kilograms. Times are in seconds. Distances are in meters.
Any cardinality of spatial dimensions may be used.
Names are optional. Any number of bodies may be specified.