time dilation

General discussion about Celestia that doesn't fit into other forums.
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chrisr
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time dilation

Post #1by chrisr » 23.02.2005, 22:05

I love the way celestia takes into account the fact that we can only see what has reached our eyes. guess i have 2 feature request. more like questions tho. Since black holes are becoming common to add into celestia, i think it makes sense to add a feature in which time is dilated according to the mass of the body it is next to. So the closer you are to body with a certain mass the faster time travels in space away from you. someone viewing you would observe time slow for you as you neard a very massive object. so can this be added to celestia?


also is there a way to make the milky way rotate (rotation period = 220million yrs(?)) ?
Just do what makes you happy provided you do not infringe on another's happiness for there is no point in living if you do not have happiness.
[tex]Happiness = \[\int_a^b \int_c^d \int_e^f \int_g^h U(x,y,z,t)\,dx dy dz dt\] = 42[/tex]
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Post #2by dirkpitt » 24.02.2005, 00:25

Yes, yes, this kind of stuff would be great! Even greater if Celestia could also simulate Doppler shifting and
other relativistic effects. Probably not such an essential feature though.

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Post #3by Tanketai » 24.02.2005, 04:22

Yeah, Doppler effect would be great! Imagine a blue Mars fillng your screen as you come closer, or a deep red Earth as you move away!
:D

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chrisr
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copy paste

Post #4by chrisr » 24.02.2005, 05:46

you coders should just copy and paste the code from star strider for relativistic effects!
Just do what makes you happy provided you do not infringe on another's happiness for there is no point in living if you do not have happiness.
[tex]Happiness = \[\int_a^b \int_c^d \int_e^f \int_g^h U(x,y,z,t)\,dx dy dz dt\] = 42[/tex]
If only we knew U!

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dirkpitt
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Re: copy paste

Post #5by dirkpitt » 24.02.2005, 07:58

chrisr wrote:you coders should just copy and paste the code from star strider for relativistic effects!


I'd never heard of that program before. Just found and went to the web site... you're right, it does do
relativistic rendering! Too bad it's shareware, so we really can't just ask for the source.

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Post #6by maxim » 24.02.2005, 11:41

Well, you can ASK of course.

maxim

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Scientifically correct simulation

Post #7by andersa » 24.02.2005, 12:25

Tanketai wrote:Yeah, Doppler effect would be great! Imagine a blue Mars fillng your screen as you come closer, or a deep red Earth as you move away!

And what color should those planets be when using travel speeds above that of light? If you want Celestia to properly simulate everything in accordance with the laws of physics, you should also be prevented from travelling across the galaxy in just a few seconds.

Be careful what you wish for; someone may give it to you. :twisted:
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Post #8by Sky Pilot » 24.02.2005, 15:06

I like Star Strider's 3-D effects. P-r-e-t-t-y cool.
"In the beginning the Universe was created. This has made a lot of people very angry and been widely regarded as a bad move."

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Post #9by dirkpitt » 24.02.2005, 16:00

maxim wrote:Well, you can ASK of course.


Yes, I could. But whether the author will allow code from his closed-source, non-free program to get
included in a free, open-source program (such as Celestia) is probably a totally different issue.

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Re: Scientifically correct simulation

Post #10by dirkpitt » 24.02.2005, 16:03

andersa wrote:
Tanketai wrote:Yeah, Doppler effect would be great! Imagine a blue Mars fillng your screen as you come closer, or a deep red Earth as you move away!
And what color should those planets be when using travel speeds above that of light?


:D Pitch black?

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Post #11by Harry » 24.02.2005, 16:08

dirkpitt wrote:But whether the author will allow code from his closed-source, non-free program to get
included in a free, open-source program (such as Celestia) is probably a totally different issue.

And whether the code would be useful is again a different issue. I doubt we could simply "copy & paste" the code...

Harald

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Re: copy paste

Post #12by t00fri » 24.02.2005, 16:42

dirkpitt wrote:
chrisr wrote:you coders should just copy and paste the code from star strider for relativistic effects!

I'd never heard of that program before. Just found and went to the web site... you're right, it does do
relativistic rendering! Too bad it's shareware, so we really can't just ask for the source.


Also as an expert in these matters, I would first like to see whether the code accounts for special relativity effects correctly.
That does not seem to bother most here ;-) ...

In fact, this issue needs /considerable/ insights beyond mere coding abilities. I actually have proposed more than 2 years ago that we should tackle this, notably the color shifts and striking distortions of the field of view....It is also a challenge to the 3d graphical implementation!


Bye Fridger

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Post #13by GregVDS » 10.03.2005, 10:14

This was the thread I was searching!

I wanted to post a request for relativistic effects like the ones I knew from star strider some years ago.

I would implement it as a toggle option: Celestia, movements, speed, acceleration, and supra-luminic ability, as usual, Press a key, relativistic effect, limited to c.

The effects should be adjustable, like in star strider, using colorshift, or not, and so on.

Pleaase! Do it

All the best

GregVDS

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Post #14by st031976 » 22.05.2005, 19:40

and the time correction (LT) for all objects not only planets, please :)

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Post #15by t00fri » 22.05.2005, 19:47

st031976 wrote:and the time correction (LT) for all objects not only planets, please :)


There was a good reason why I switched LT off beyond the limits of the solar system. Think about it...

Bye Fridger

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Post #16by t00fri » 22.05.2005, 19:53

GregVDS wrote:This was the thread I was searching!

I wanted to post a request for relativistic effects like the ones I knew from star strider some years ago.

I would implement it as a toggle option: Celestia, movements, speed, acceleration, and supra-luminic ability, as usual, Press a key, relativistic effect, limited to c.

The effects should be adjustable, like in star strider, using colorshift, or not, and so on.

Pleaase! Do it

All the best

GregVDS


It makes little sense to incorporate relativistic effects without also realizing all these striking effects like field of view distortions and color shifts. This is a major challenge graphically and also as concerns the CPU power. Not everyone uses a similarly fast machine as I do, for example. The Celestia engine has a lot to chew on anyhow and it's a matter of compromise where to place the main emphasis if compromises have to be made.

But relativistic effects are certainly on our "shopping list" since a long time.

Bye Fridger

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chrisr
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confusion

Post #17by chrisr » 12.06.2005, 19:17

Some of you guys seem to be confused by the way you travel in Celestia. In celestia you don't travel relativistically. You travel as a god beyond physics. Or you can think of it as traveling with warp. That is to say, you travel within a bubble of space. Where space can be thought of as contracting in frount of you or expanding behind you..whatever.

However, as the physics show, you don't need to travel faster than light to get where you want when you want. If you want to reach the Andromeda galaxy in 5 minutes, there is a given percentage of the speed of light which you can travel to get there within that time contraint. Or if you wanted to travel to the Pillars of creation in a minute, there is such a percentage of c which you can travel to do so as well.

An object traveling at the speed of light, albeit a massless object, will travel everywhere and everywhen in ZERO time.
Just do what makes you happy provided you do not infringe on another's happiness for there is no point in living if you do not have happiness.
[tex]Happiness = \[\int_a^b \int_c^d \int_e^f \int_g^h U(x,y,z,t)\,dx dy dz dt\] = 42[/tex]
If only we knew U!

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Post #18by selden » 12.06.2005, 20:46

Another way to look at it is that when you run Celestia, you change your viewpoint. You don't move.

Moving objects are defined in catalog files. I think it would be interesting if those objects could be defined to travel relativisticly, but I don't expect that would happen any time soon.
Selden

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chrisr
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yeah

Post #19by chrisr » 13.06.2005, 02:53

Yeah, that would be really awesome. I was thinking and i'm sure this has been thought of before, but i have an idea relating to the fact that the opengl has problems accurately drawing objects beyond a certain distance from the sun. Instead of things being so heliocentric, maybe a certan radius from the sun can be selected. So lets say only stars 200lightyears away from the sun are drawn relative to it. Then 6 six stars that are appoximately equidistant from each other on this imaginary sphere with radius 200ly, can be used as reference to draw stars around them with the same radius. and so on...
Just do what makes you happy provided you do not infringe on another's happiness for there is no point in living if you do not have happiness.
[tex]Happiness = \[\int_a^b \int_c^d \int_e^f \int_g^h U(x,y,z,t)\,dx dy dz dt\] = 42[/tex]
If only we knew U!


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