Welcome, Guest

Author Topic: The Figure 8  (Read 3298 times)

Maxpm

  • *
  • Posts: 4
The Figure 8
« on: May 29, 2011, 04:19:47 PM »
How can orbits be set up like those in the "The Figure 8" demo simulation?

Omnigeek6

  • *****
  • Posts: 111
Re: The Figure 8
« Reply #1 on: May 30, 2011, 12:16:11 AM »
How can orbits be set up like those in the "The Figure 8" demo simulation?

Don't bother. They're incredibly unstable.

frankdepinte

  • **
  • Posts: 17
Re: The Figure 8
« Reply #2 on: June 01, 2011, 01:01:31 PM »
How can orbits be set up like those in the "The Figure 8" demo simulation?
.
You should input initial values for the position and velocity of each of the planets , and give them the same mass . If you alter the masses also the initial conditions should be changed ! Initial data  can be retrieved googling for Figure Eight .

Or , you can enter the following data for instance :
Mass P1 1.98891691172466E+30
Mass P2 1.98891691172466E+30
Mass P3 1.98891691172466E+30
Mass P4 5.97369125232005E+24

Rx Ry Rz Vx Vy Vz of planets (in km and km/s)
P1 : 727503270,-182315647.5,0,6.198776,5.748857,1e-9
P2 :  -727503270,182315647.5,0,6.198776,5.748857,0
P3 : 0,0,0,-12.3976,-11.4977,0
P4 : -150000000,0,0,-12.3976,-40.4977,0

Thissetup will generate an Eight surrounded by an Earth sized planet
. Of couse you can omit the fourth planet

 BTW  : the system is very stable . Small offsets from initial data or tolerated .

Dan Dixon

  • Creator of Universe Sandbox
  • Developer
  • *****
  • Posts: 3244
    • Personal Site
Re: The Figure 8
« Reply #3 on: June 13, 2011, 12:35:20 PM »
I don't see a way to get the starting values for the objects, but here's a JAVA app that show's a number of interesting n-body / gravity scenarios (including the figure eight):
http://www.princeton.edu/~rvdb/JAVA/astro/galaxy/Galaxy0.html