complexities of a simple experiment

[tskaze]

Theres the classic experiment in which someone is sent into space, rides around at a high speed, and comes back to everyone being older. Im assuming the reasons for this are well understood by the forum community. But what if the people on earth were to build a device capable of tracking the spacemans craft, and sending a video/audio signal to him. How would they appear? would they seem to be moving in a "fast forward" sort of motion, or would they jump ahead as the spaceman decellerated? I have a vague grasp of this, but im looking for some more definite understanding. Also, for the purposes of eliminating variables, the spaceman is moving at about 99.9% of c

[J.C.MacSwell]

Theres the classic experiment in which someone is sent into space, rides around at a high speed, and comes back to everyone being older. Im assuming the reasons for this are well understood by the forum community. But what if the people on earth were to build a device capable of tracking the spacemans craft, and sending a video/audio signal to him. How would they appear? would they seem to be moving in a "fast forward" sort of motion, or would they jump ahead as the spaceman decellerated? I have a vague grasp of this, but im looking for some more definite understanding. Also, for the purposes of eliminating variables, the spaceman is moving at about 99.9% of c

 

On the trip "out" the spaceman would "appear"(my "calculated" assessment of how he functions in my "inertialesque" frame based on Earth) to have time very much slowed down for him.

 

The video signal would seem even slower.

 

On the trip "back" the spaceman would "appear"(my "calculated" assessment of how he functions in my "inertialesque" frame based on Earth) to have time very much slowed down for him. (same as trip "out")

 

However, the video signal would seem much faster (look like fast forward)

[Spyman]

And when he comes back the spaceman is younger not older than the time past on Earth.

[geistkiesel]

Quote:

Originally Posted by tskaze

Theres the classic experiment in which someone is sent into space' date=' rides around at a high speed, and comes back to everyone being older. Im assuming the reasons for this are well understood by the forum community. But what if the people on earth were to build a device capable of tracking the spacemans craft, and sending a video/audio signal to him. How would they appear? would they seem to be moving in a "fast forward" sort of motion, or would they jump ahead as the spaceman decellerated? I have a vague grasp of this, but im looking for some more definite understanding. Also, for the purposes of eliminating variables, the spaceman is moving at about 99.9% of c [/quote']

First, for a 10 year round trip of the ship, the earth based recorder would see every instant of the space ships's motion. And assuming the earth radiated signal was emitted as the events occured on earth, plus the events sent back to earth from the ship were reradiated when received, the ship can compare al earth events with ship events.

ALl events for the earth measured 10 year time frame will be contained in the video that contains all the space ship activity in that same measured earth frame 10 years,

 

Will the moving twin see itself slow down in growth rate while watching her earth twin age substantiallyt faster ?

I seriously doubt it.

Geistkiesel