Welcome, Guest

Author Topic: Relativistic Universe Sandbox 2  (Read 10966 times)

raxo2222

  • ****
  • Posts: 34
Relativistic Universe Sandbox 2
« on: February 21, 2011, 02:28:35 AM »
It is possible that Universe Sandbox 2 could run on Special and/or General Relativity Theory?
This would be fun. Newtonian Gravity is pretty boring. That simulator would switch between these theories.

Omnigeek6

  • *****
  • Posts: 111
Re: Relativistic Universe Sandbox 2
« Reply #1 on: February 21, 2011, 06:00:53 PM »
It is possible that Universe Sandbox 2 could run on Special and/or General Relativity Theory?
This would be fun. Newtonian Gravity is pretty boring. That simulator would switch between these theories.

What? At the speeds found in Universe Sandbox, relativity has almost no effect whatsoever. Using it for calculations would be pointless.

raxo2222

  • ****
  • Posts: 34
Re: Relativistic Universe Sandbox 2
« Reply #2 on: February 23, 2011, 07:15:10 AM »
When I play that simulator, I often make "black holes" or accelarating obiect to very huge speed like 100x speed of light, whan I set G const. milion times bigger on galaxies, or stars sim's they should behave like in relativistic theories

Dan Dixon

  • Creator of Universe Sandbox
  • Developer
  • *****
  • Posts: 3244
    • Personal Site
Re: Relativistic Universe Sandbox 2
« Reply #3 on: March 01, 2011, 08:53:03 PM »
Doing a relativistic simulation is quite a bit more complicated than just using Newton's law of gravitation.

And for solar system sized simulations, Newton's law is all you need to get very realistic results.

How do you think a relativistic simulation work? How would it be different than how it currently works?

raxo2222

  • ****
  • Posts: 34
Re: Relativistic Universe Sandbox 2
« Reply #4 on: March 02, 2011, 08:27:09 AM »
In NORMAL simulation (without black holes and low speeds) program could use NEWTONIAN laws
When I create black hole, and throw into it some obiect, black hole should behave as in REAL LIFE - using Einstein theories of grawity

Accelerating weirdly bodies (Acceleration like >>1000m/s^-2) should drop in acceleration as speed increases to speed of light
 

Darvince

  • *****
  • Posts: 1842
  • 差不多
Re: Relativistic Universe Sandbox 2
« Reply #5 on: March 02, 2011, 04:05:42 PM »
Which would make it lag every time you change an object to a black hole.

raxo2222

  • ****
  • Posts: 34
Re: Relativistic Universe Sandbox 2
« Reply #6 on: March 09, 2011, 03:21:51 AM »
When masses or speeds grow to extreme - 10% of speed of light, or escape velocities will be above 10% of speed of light, simulator could gently swith between Newtonian and Einstein gravity.

Dwatson251

  • *
  • Posts: 5
Re: Relativistic Universe Sandbox 2
« Reply #7 on: April 30, 2011, 08:56:19 AM »
I recently purchased the game and signed up to the forum to find a topic such as this one and I'm all in favour of it. I don't know much about it, but I would love to see the effect it has with much larger masses in space.

surreal

  • *
  • Posts: 1
Re: Relativistic Universe Sandbox 2
« Reply #8 on: April 30, 2011, 04:10:14 PM »
I recently purchased the game and signed up to the forum to find a topic such as this one and I'm all in favour of it. I don't know much about it, but I would love to see the effect it has with much larger masses in space.

I think that simulating GR is beyond the scope of this simulator.
If you want to simulate GR you have to find the metric tensor first, this basically involves solving a set of non linear PDEs. I haven't seen a simulator capable of performing this step in anywhere near realtime.
It's possible to do a weak-field approximation, but still you won't be able to do really dense and large masses (like black holes).
With weak field approximation, it's possible to get the solar system right though :)

lexman6

  • *
  • Posts: 5
Re: Relativistic Universe Sandbox 2
« Reply #9 on: April 30, 2011, 04:58:52 PM »
Relativity in this would be awesome. I found it kinda annoying when I decided spawn earth around a 1 light yr diam star to find earth going at 8c.

You could just have the planets increase thier mass as they get past 0.9c (diam must stay the same). That would make it much more realisitic.
Black holes need to destroy/freeze what get close to them as well as a side note.

As for other properties

Length - I dont know if the engine supports objects changing shape. Anyway, you would have to calculate what velocity the camera is going and change the length accordingly which would be hard.

Light - C is constant everywhere. Same problem with length, you would have to calculate camera velocity. Even then if you calculated that, I dont know how you could represent the light properly without making the game unplayable.

But mass changes would be awesome and I would imagine not too hard. At least not hard compared to the above two.