Stargazing Different Simultaneity for telescopes in space and earth?

AI Thread Summary
Lorentz transformations indicate that simultaneity of events is frame-dependent, leading to potential time differences when observed from different reference frames. For space-based objects, the time difference calculated is approximately 10 seconds for events separated by 100 Mpc, assuming a low velocity. However, when observing distant transient sources, telescopes will not detect a noticeable time difference due to the light travel time, as they will observe the events simultaneously. The confusion arose from mixing the timing of the signal emissions with the observation times, which remain consistent across different telescopes. Ultimately, the observation timing aligns despite the differing perceptions of event simultaneity.
ofirg
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I was just wondering. According to Lorentz transformations, if two events are simultaneous in one reference frame, they will generally not be simultaneous in another.
The time difference that I get between the two events in the other reference frame is

\Delta t^{`} = \gamma\beta\Delta x \approx {\Large \frac{\beta^{3}}{2}} \Delta x

Where the approximation assumes \beta \ll 1

Now, for space born objects \beta \approx 3 \cdot 10^{-5} so

\Delta t^{`} \approx 10^{-14} \Delta x where \Delta x is in light time.

If one takes a distance of 100 Mpc then \Delta t^{`} \approx 10 sec

So If I have two distant transient sources that give a signal at more or less the same time on earth, a space telescope will observe them at a noticeable time difference?
 
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No. You can never observe distant sources as they are "simultaneously" to the observation due to light travel time. Telescopes at the same event in motion wrt each other will observe distant objects in the same state (modulo redshifts and aberration).
 
Thanks For the reply.

I see now that I mixed up the times that the telescopes will assign to the events themselves ( the time that the sources output the signal) which will be different And the time of observation, which will be the same.
 
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