
True Time Travelers - nixtaken
https://kirstenhacker.wordpress.com/2020/08/20/true-time-travelers/
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firebaze
Relativity implies that a moving clock experiences less passing time than a
resting clock (relative to an observer). The "slowness"-factor gets higher the
closer you get to light speed, reaching infinity (i.e. impossible) precisely
at light speed.

In the example the one twin travels to a distant star with an appreciable
fraction of light speed, thus ages slower. Then, the twin travels back, again
with an appreciable fraction of light speed, and still ages slower.

This is basic relativity theory. Maybe I understand the article wrong, but
from what I read I understood that the twin should somehow "catch up" on his
travel back.

I'd love to be corrected.

~~~
nixtaken
It implied that the temporal effect of the final deceleration was analogous to
how when you throw a ball up in the air and catch it, it only momentarily
feels heavier than before you threw it. The twin only momentarily looks
younger because the clock has to speed back up during the final deceleration
and a naive calculation neglects this step.

~~~
simonblack
This isn't that bus that will explode if it gets slower than 60 mph.

According the the article, during the final deceleration, the space traveller
will age 20 or so years. In other words, for the traveller, that deceleration
phase is going to last 20 years.

~~~
nixtaken
Or they just burst into flames. It is like burning up on re-entry. You are
thinking of acceleration in the same way you were taught to think about
velocity, but that doesn't work in this case.

