Transmission time of fast rocket

[Guest Joemc]

I thought about a ship leaving the earth with a camera at the front that maintains a constant broadcast back to earth.

 

Hypothetically, if that ship accelerated to the speed of light quickly, what would happen? I would have thought that irrespective of the speed of the ship, the video broadcast should travel back to earth at the speed of light. But I suppose what confuses me is what happens if the camera is permanently on, does it allow you to get an image of alpha centaury faster than a ship that turns its camera on when it gets there?

 

For example: A ship is sent to alpha centaury at the speed of light. When it gets there, it takes a photo and sends it back to earth. So the time it takes to see the photo on Earth is the trip time of the ship plus the transmission time of the photo (8.6years). But if the camera is on from the start and constantly broadcasting to earth we won't get a video feed of the star in only 4.3 years. Because of this, does the video images on earth slow down as the ship increases its distance from earth?

 

Yes I know it would be impossible, but I figure that the video feed on earth should slow down. Say after 2 years something shoots by the rockets video field of view, two years of broadcast have occurred on earth but the image of what flew by will take another 2 years to reach. Therefore in the end when the ship gets to alpha centaury 4 years of transmission will take 8 years to be viewed on earth. This concept of video slowing down seems weird

 

My question directly relates to how the speed and distance of the rocket effects the constant video transmission on earth. The rocket only broadcasts for 4.3 years (until it reaches Alpha centaury) but because of the increasing distance from earth what the rocket sees, progressively takes longer to reach and appear on the video screen. For this to happen does the time frame of the video slow down as the ship moves away? If the video feed included a clock at the bottom of the screen would it show 4.3 years passing over 8.6 years earthtime? and if the rocket is aproaching earth from the same distance, will we get the entire video feed at once?

[Guest Joemc]

If the video does slow down, does same thing happens to a star with a relative speed away from earth approaching c. Do we see that star age 2x as slow as it does from its perspective? If that star is approaching earth near c, do we see that star age faster?

And finally does the relative speed effect the period of variable stars we see from earth (approaching c towards us = faster observed period, while approaching c away from us = slower observed period)?

 

I am obviously not a physicist but when I think about it seems logical. But then again I could just be confused?

[swansont]

Any scenario that follows the pattern of "This is impossible, but what would happen if..." is ill-formed.