Neddy Bate
Valued Senior Member
You make a good point that we should avoid talking about perceptions. I guess I just assumed everyone knows to disregard doppler effect and delay-effects caused by c being finite. That way it does not have to be stipulated for every scenario. For example, if the female's ship is approaching at relativistic speed, she would appear in fast-motion not slow motion, but I referred to the slow motion because I already disredarded the doppler effect.Billy T said:No it is real, but I am not speaking of what he sees via the telescope. I don't want (or have time) to think carefully about his view. If she is raisng her arm, the lower part of the movement was imaged by lght that traveled a longer distance to his scope (if he was not moving) than the top of the arm movement, so his perception would be even slower motion that the facts due to time passing more slowly. I try to avoid talking about the perceptions.
I have been following your exchanges with MacM, and I am hoping that you or someone can finally explain away the reciprocal time dilation problem. I don't think it has been explain satisfactorily yet, but that does not mean that I reject SRT outright.Billy T said:It is a paradox only if true and strange. (I am not saying it is not, only that I don't understand exactly what you are saying.)
Good, I guessed correctly what you were trying to state. And yes it is a reciprocal effect - the biological processes of both are proceeding more slowly than if they were in the same frame. - this is the paradox MacM and I have been disputing here (He may say it is not a paradox as SRT is false on this.) I suggest you read our exchanges, I defend what seems "impossible" and MacM believes it is impossible that time can be passing more slowly in each frame than in the other. I bet it seems very clear to you that MacM must be correct on this. Again read our exchanges.
Very well, I will try not to focus on the acceleration. I knew it was not supposed to be the cause but I did think that it was during this time that the clocks changed radically.Billy T said:A better way to remove acceleration as an explanation of the change in aging rates is to just let it last very short period by anybody's clock compared to the time "drifting in inertial frames". SRT predicts that the cummulated aging effects is linear in this drift time and can say nothing about the accelerating periods as SRT only applies to inertial frames (GR is much more complex and I don't generally comment on it as I am likely to be wrong.)
Yes you are wrong in your focus on the aceleration periods - forget about the accelerations.
I bet you have heard that the "twin paradox" is not symetric as only one twin experience "acceleration" and he is the one that comes home young. That is all true, but his period of acceleration does not cause his youthful state upon return.
In closing, let me ask one thing that might help me to finally grasp this:
Is there supposed to be such thing as 'real' motion which induces time dilation and 'real' rest which does not induce time dilation? I thought relativity theory forbids a preferred frame of reference. Because if I cannot focus on acceleration in the twin paradox, then how can I possibly detect which twin will be younger unless I choose a preferred frame?
Oh no, now I am totally confused. Check out this website.
http://www.phys.vt.edu/~jhs/faq/twins.html
(Scroll down to the short section at the bottom.)
This is a pretty good explanation of the twin paradox, but there is one short section at the bottom of the page that treats the twin paradox without acceleration. What the #$^&*? ...Oh lord, now it looks like there is a preferred reference frame. Someone please tell me this is wrong!