Relativity in Orbiter: When?

[Clavius0712]

Hi,

I've been reading a lot lately about how Einstein's "field equations" enable the prediction of things that otherwise cannot be accounted for by Newton or Kepler. A nice example is the precession of Mercury's perihelion (see link):

Kepler Problem

This got me thinking, would it be possible one day for Orbiter to use Einstein's equations rather than Newton's or Kepler's? I know it would probably be difficult to do but the equations are out there already waiting to be used and have been verified as accurate by numerous experiments.

For most spacecraft in Orbiter there would be no noticeable difference, but if anyone designed a ship capable of reaching sub-light speeds, it would make for an amazing simulation.

 

[the.punk]

Yes that is what I want.
Orbiter must be relativistic. I want also the timedilatation in orbiter.
When you're travelling near light speed you colocks run slower than the on the earth.
Cool idea. I always wondert about this.

 

[Urwumpe]

Well, martins already started a discussion on if relativistic effects would be desired.

 

[the.punk]

Is there a thread in this forum or in an other forum?

 

[MAraujo]

Time dilation would be an issue when trying to coordinate rendezvous but perhaps this could be solved by giving each ship its own clock, the hard part is spacial distortion, at sub-light speed you would see distances shrink in the direction of travel, this would mean that the whole solar system would look different depending on which ship you focused on. It boggles my mind to think of how such a problem would be solved in orbiter.

 

[the.punk]

My solution would be that you can have different clocks on your own ship. You can have your own clock and you can have an other clock displaying the time on an planet or an other ships.
And yes every ship would have its own clock.

 

[Dig Gil]

I like this idea too, it would give some good effects with time a high-speed travelling.

 

[Artlav]

The visual distortions are the least of the problems.
The big problems are that there are still some experimental blind spots in relativity, and that some kind of handwaving has to be done about temporal paradoxes that are expected in the thing.
And that is only special relativity.

 

[Clavius0712]

...temporal paradoxes...

I thought they were only in Star Trek!

Seriously though, aren't Einstein's equations used all over the place now, for predicting the orbits of new satellites and the like? I'm no mathematician by any means but from what I've read the equations Einstein came up with really do predict the motions of pretty much everything, including accounting for anomalies like the precessing orbit of Mercury, whereas the equations of Newton and Kepler are really only approximations which work at sub-relativistic speeds.

Am I missing something here or is this not just a case of plugging in the right equations?

 

[the.punk]

Can you give an example of temporal paradoxes?

 

[MAraujo]

The visual distortions are the least of the problems.

I think the problem is that the spacial effects are not visual distortions, they are spacial distortions. The distances actually change with your velocity. Maybe this could be simulated using only visual effects... but you be missing out on the special relativity part

 

[Clavius0712]

Just found this and am downloading it now. It seems some people have already written programs simulating relativistic optical effects.

Realtime Relativity

 

[Artlav]

A focused vessel sets out to Betelgeise in 2056 at near the speed of light, arriving there in a minute of user time, in 2435. User switches to another vessel left at home and in 2056, sees the first vessel departing (a problem to program in itself), and puts his vessel in first's path. Voilla the temporal paradox.

Vice versa - he sets towards Betelgeise, arriving in 2434, yet, the first vessel arrived and didn't see it.

---------- Post added at 12:15 AM ---------- Previous post was at 12:13 AM ----------

I think the problem is that the spacial effects are not visual distortions, they are spacial distortions. The distances actually change with your velocity. Maybe this could be simulated using only visual effects... but you be missing out on the special relativity part

You mean A - simulate SR, i speak about B - draw what the pilot will see. Two different things.

 

[Clavius0712]

What we all have to remember is that these are just numbers in a computer, so we should be able to simulate non-euclidean geometry quite easily compared to trying to make some sort of physical model like one of those old mechanical models of the Solar System people in the 19th century used to marvel at.

Geometry in a computer is basically whatever you tell the computer it is.

 

[Urwumpe]

Can you give an example of temporal paradoxes?

I think he means the twin paradox, which is no paradox if you use special relativity correctly - the twin paradox only exists as long as you don't take in account the direction of the velocity vector and the related integrability of the velocity function.

 

[Hielor]

I think he means the twin paradox, which is no paradox if you use special relativity correctly - the twin paradox only exists as long as you don't take in account the direction of the velocity vector and the related integrability of the velocity function.

From his explanation he's actually talking about the problems of simultaneously simulating different time-rates in a computer simulation, and allowing the user to visit each.

 

[MAraujo]

Amen Urwumpe, other so called "paradoxes" that I've seen like the train-tunnel paradox, are easily solved once you let go of the notion of simultaneity.

 

[Urwumpe]

From his explanation he's actually talking about the problems of simultaneously simulating different time-rates in a computer simulation, and allowing the user to visit each.

Yes, but this is no problem if the user has to MOVE to the new frame. Orbiter would maybe need to pause a moment to allow transition over longer distances in spacetime, but this can be solved mathematically.

 

[ar81]

Time dilation would be an issue when trying to coordinate rendezvous but perhaps this could be solved by giving each ship its own clock, the hard part is spacial distortion, at sub-light speed you would see distances shrink in the direction of travel, this would mean that the whole solar system would look different depending on which ship you focused on. It boggles my mind to think of how such a problem would be solved in orbiter.

Space distortion = Distortion matrix X normal space

 

[Andy44]

Martins started a thread about this a while back, it might be over on m6(?).

His bottom line was that you can't do relativity in Orbiter as it currently set up.

He was kicking around the idea of building a seperate program to demonstrate relativity, which would be a different type of simulator. The thread faded and he is presumably busy working on other stuff.

Since it requires a new program, maybe someone else could build a relativity demonstrator? Bonus points if it's "flyable".