That is pretty much correct. The chances that a star will physically collide is negligable. Instead what we define as a collision is a gravitational interaction.
How was the force on each particle calculated? 160000^2, that's 25.6 billions of interactions in each time step... Any particular algorithm or method used?
@TriKri Hmm...I guess I forgot to answer your post. The forces are calculated with newtoniian gravity where the force of gravity is determined through an approximation called the tree approximation which sorts particles spatially. Groups of particles at a distance are approximated by their center of mass and total mass of the particles in the group. Close particles are treated individually. Cool?
Does this use newtonian physics? Or is general relativity a factor? Also, it appears that a lot of energy is lost as the galaxies collapse, is this an illusion? How is the energy lost?
Newtonian physics is used in the simulation. Relativity is not important. Energy is conserved to within in 0.0001 percent. It may give the impression that energy is not conserved, but in reality the galaxy/custer orbits change because the galaxy orbital energies is redistributed into the other forms like the dark matter distribution and other galaxy orbits. The total energy in the system is conserved.
That is pretty much correct. The chances that a star will physically collide is negligable. Instead what we define as a collision is a gravitational interaction.
rberring 5 months ago
Nothing actually physically "collides" right, stars, planets, etc. Just wondering lol.
hL4x 5 months ago
How was the force on each particle calculated? 160000^2, that's 25.6 billions of interactions in each time step... Any particular algorithm or method used?
TriKri 1 year ago
@TriKri Hmm...I guess I forgot to answer your post. The forces are calculated with newtoniian gravity where the force of gravity is determined through an approximation called the tree approximation which sorts particles spatially. Groups of particles at a distance are approximated by their center of mass and total mass of the particles in the group. Close particles are treated individually. Cool?
rberring 11 months ago
@rberring Yeah, no prob. I investigated it further; it's called Barnes-Hut, right? Nice visualization by the way!
TriKri 11 months ago
I love how there are clouds of individual stars being ejected and hovering around nearby at each close pass :)
Baleur 2 years ago
awesome
maul316 3 years ago
I am glad you enjoyed the movie. I had fun both simulating and making the movie.
rberring 3 years ago
Does this use newtonian physics? Or is general relativity a factor? Also, it appears that a lot of energy is lost as the galaxies collapse, is this an illusion? How is the energy lost?
Libertarianist 4 years ago
Newtonian physics is used in the simulation. Relativity is not important. Energy is conserved to within in 0.0001 percent. It may give the impression that energy is not conserved, but in reality the galaxy/custer orbits change because the galaxy orbital energies is redistributed into the other forms like the dark matter distribution and other galaxy orbits. The total energy in the system is conserved.
rberring 4 years ago