Absolute coordinates in the univers

[Edgard Neuman]

Hello,

 

It seem to me that there is a way to measure absolute coordinates of any events in the univers, using the cosmic background.

First, you have to correct the relativist effect of speed, using the measurement of the Doppler effect affecting background (it give you the absolute speed)..

 

Then, you can measure the size of the observable univers at this moment : it give you an absolute age for the event.

 

From a event, you can define the trajectory where background relative speed stays null (the time trajectory), and the spatial surface where the background age stays the same (the spatial (3d) plane component).

 

You can now simply measure coordinates of any events using its time trajectory, by finding the point where it touches the reference event's plane. Time difference along the trajectory give you time "coordinate" and, position on the spatial plane give you spatial coordinates (though it should be a curved space)..

First : is there any relativist problems with that ?

What is the function that transform coordinates from a reference to another.. ?

 

[swansont]

That's not a preferred frame, in the sense that you get the true answer in that frame and the wrong answer in other frames. That's what a preferred frame is in relativity, and why we say there is none. No preferred frame means you can't tell if you are moving or at rest with respect to an arbitrary frame if you are in a sealed box; all of your physics works the same.

 

The CMB is simply a convenient frame to use since everyone could, in principle, use it, if they have access to the night sky.

[ajb]

The CMB is simply a convenient frame to use since everyone could, in principle, use it, if they have access to the night sky.

Exactly and this frame is often used in cosmology.

 

 

The mantra is: Physicists may have prefered frames, but physics does not!

[Edgard Neuman]

I understand that, and I don't imply that the comoving frame has any effect on local physics (other than background microwaves).. I'm just wondering if it could be used to create a coordinate system for real events...

If a spaceship (with a stars database) emerge at a random point in space time, could it tell where and when it is ?

Edited August 13, 2013 by Edgard Neuman

[ydoaPs]

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Moderator Note

To prevent taking the thread off-topic, an off-topic post has been given its own thread.

[imatfaal]

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Moderator Note

 

Leif

 

You had just had a topic split off and you went off on a complete tangent yet again - your latest post regarding the predestination of light has been split off to the trash. Your actions are considered hijacking and are against our rules. Do not do it.

 

[Leif]

How can you suggest in good faith that irrational time is not the ultimate absolute co-ordinate in the universe? I think you need to re-examine your education if you are so threatened by the truth!

[imatfaal]

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Moderator Note

 

Leif

 

Please do not respond to moderation within the thread - it continues the hijack and distracts from the topic. When a poster mentions irrational time I think of Bartok not absolute universal coordinates - thus the post was trashed.

 

If you have an idea you wish to expand upon regarding this then open a new thread in the Speculations Forum - do not start posting in a thread on the use of the CMBR as a coordinate system.

 

If you feel this moderation is unjust then report this post