TODO

Add collisions

• When 2 particles come close enough to each other, they become one particle
• New particle's mass will be equivalent to the sum of the original particles' masses
• New particle's momentum will be equivalent to the sum of the original particles' momentums

Add visual representation of size

• Radius of particle is proportional to its mass

Add initial disk rotation

• When the disk of particles is generated, particles are more likely to have an initial velocity tangent to the center

Get simulation settings from user, rather than having them pre-defined in the source code

• Use the console to ask for settings