Gravity wells (split from A Question for Curved Spacetime)

[geordief]

1 minute ago, Sensei said:

Complete, with micro-scale asteroids? They are made every day, every second.. new free particles in cosmic space, especially solar wind are emitted by Sun, planets, etc. so complete data is not possible due to never enough amount of data..

..but to some level of accuracy, based on sizes of cosmic objects, it's not a big problem..

Yes ,I only had in mind what would be practical (and enlightening  for me)

 

Is there  anywhere that these spacetime  graphs have been written down?

 

Some sort of a graphic spacetime depiction of   the Solar system   at some particular time (say t=01/01/2000  at midnight)

If there was  then we could  make adjacent snapshots (eg t=24  48 ,72 hours later  etc ) and run the  snapshots like a movie.

 

Accuracy not important ,just maybe as a way of looking at spacetime events in a  non local  way?

[Sensei]

No GR is needed to simulate macroscopic objects.

There are online simulations of Solar System available to play e.g.:

https://www.solarsystemscope.com/

set the date you want.

 

[geordief]

1 hour ago, Sensei said:

No GR is needed to simulate macroscopic objects.

There are online simulations of Solar System available to play e.g.:

https://www.solarsystemscope.com/

set the date you want.

 

I just meant to simulate the map of curvature around and extending from  the objects in the Solar system.

I wasn't interested  in actually  seeing the objects themselves.

Would that be possible?

[swansont]

22 minutes ago, geordief said:

I just meant to simulate the map of curvature around and extending from  the objects in the Solar system.

I wasn't interested  in actually  seeing the objects themselves.

Would that be possible?

These give you the 2-D shapes of the gravity wells, which would be related

http://www.projectrho.com/public_html/rocket/spacemaps.php#xkcdgrav

[geordief]

40 minutes ago, swansont said:

These give you the 2-D shapes of the gravity wells, which would be related

http://www.projectrho.com/public_html/rocket/spacemaps.php#xkcdgrav

Yes,that is the sort of thing(I was looking for the way the   different gravity wells joined up)

It wouldn't be a problem to add the 3rd spatial dimension (and use  3d glasses) and to run a series of those still frames  too  get the time dimension, would  it?

[geordief]

1 hour ago, studiot said:

point of spacetime is that the timelike and spacelike dimensions have a quadratic relationship, not a linear one so you can't separate them.

Are you saying that that would just be pretty pictures but that it wouldn't show anything profound -and might actually   be misleading,like the trampoline analogy?

If you were to populate  my 3d  movie  with an additional moving object (or a beam of light) wouldn't  that object's  trajectory  be very realistic?

Are there relativistic  effects that this movie cannot capture?

 

[geordief]

Edit:On reflection I see where this "model" falls down as I described it.

 

Could it be improved by paring down the Solar system to just a few objects,say the Sun ,Earth and Jupiter as well as  allowing for different frames of reference with their own clocks.

Introduce a test object moving at relativistic  speeds and compare how the movie plays out from the different frames of reference.

 

Could it be a nice pedagogic tool?

Edited June 25, 2022 by geordief

[studiot]

1 hour ago, geordief said:

Are you saying that that would just be pretty pictures but that it wouldn't show anything profound -and might actually   be misleading,like the trampoline analogy?

If you were to populate  my 3d  movie  with an additional moving object (or a beam of light) wouldn't  that object's  trajectory  be very realistic?

Are there relativistic  effects that this movie cannot capture?

 

Very quickly

There have been some very good animations of the 'distortion' caused by speed.

1) Ask Janus, he posted some.

Also this earlier thread, I havent had time to review it though.

The university of Oz seems legit.

 

[geordief]

9 minutes ago, studiot said:

Very quickly

There have been some very good animations of the 'distortion' caused by speed.

1) Ask Janus, he posted some.

Also this earlier thread, I havent had time to review it though.

The university of Oz seems legit.

Thanks.We cross posted "simultaneously".I will take a butcher's at that thread.

Thanks.We cross posted "simultaneously ".Will give that thread a butcher's

Edited June 25, 2022 by geordief

[geordief]

Sadly the content of that link a bit old now (2007) and I can't get anything there to play.

 

Actually,in any case I was more interested in proper  3d videos or virtual reality videos** if such exist (not that I have the facility to play them either) 

 

I get the impression that this kind of a thing might not be for the general public and perhaps used in university settings.

 

If anyone has hands on experience  with that sort of thing it would be interesting to hear.

 

**perhaps "games" might be a better descriptor  as I was imagining that there could b quite a few settings to play around with.

Edited June 26, 2022 by geordief

[md65536]

On 6/26/2022 at 4:54 AM, geordief said:

**perhaps "games" might be a better descriptor  as I was imagining that there could b quite a few settings to play around with.

There's http://gamelab.mit.edu/games/a-slower-speed-of-light/

It doesn't have a lot of options but it's built on an open-source Unity toolkit. The description says it shows time dilation (objects should be slower the closer you are to the speed of light) but I don't see it, and I also don't see delay of light (objects should appear faster as you approach them); it might be the effect is too small for me to notice.

[md65536]

On 6/28/2022 at 7:54 PM, md65536 said:

There's http://gamelab.mit.edu/games/a-slower-speed-of-light/

This demonstrates visual effects of SR by the way, not GR, and is not applicable to this thread. I wasn't paying attention to which topic I was in!

[geordief]

3 hours ago, md65536 said:

This demonstrates visual effects of SR by the way, not GR, and is not applicable to this thread. I wasn't paying attention to which topic I was in!

Ah,yes.Actually I hadn't actually  got round to  looking at it but yes it would be the gravity wells  depiction that I was after (but with the full-ish SR effects included -and "playable" ).

 

I imagine that at some academic or research level such simulations might  be in use  but probably not for the general public.

 

In the past Markus has shown me  gravity simulations on a 2d level  where there  were settings that could be adjusted for mass  and position  but that was not quite what I had in mind now.

 

 

[md65536]

On 7/1/2022 at 1:47 AM, geordief said:

Ah,yes.Actually I hadn't actually  got round to  looking at it but yes it would be the gravity wells  depiction that I was after (but with the full-ish SR effects included -and "playable" ).

I imagine that at some academic or research level such simulations might  be in use  but probably not for the general public.

Well it depends on what you're looking for, a model that shows things in a simple way, or a rendering of what would be seen by your eyes. The movie Interstellar shows visual effects around a black hole, and I think they needed a lot of time on a supercomputer to render them.

In the SR game above, it doesn't include all the effects of SR, and yet the result is still confusing enough to the eye that you can't easily see what's going on. For Interstellar, they ignored the Doppler effect for artistic reasons. So even these are simplifications relative to what would actually be seen.

[geordief]

2 hours ago, md65536 said:

Well it depends on what you're looking for, a model that shows things in a simple way, or a rendering of what would be seen by your eyes. The movie Interstellar shows visual effects around a black hole, and I think they needed a lot of time on a supercomputer to render them.

In the SR game above, it doesn't include all the effects of SR, and yet the result is still confusing enough to the eye that you can't easily see what's going on. For Interstellar, they ignored the Doppler effect for artistic reasons. So even these are simplifications relative to what would actually be seen.

I was really  just  looking for a  souped up version of what Swansont  posted  up above

A 3d version of that which could be played from different reference  frames and   might  show the effect of disturbances to the system (eg what would happen  to the  shapes of the different gravity wells -and positions of the objects at their centres- if a rogue planet  passed through  the Solar System?)