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I saw a statement that if you have a clock on Earth and a clock on a space ship, and the spaceship moved away from Earth at a significant percentage of light speed, people on both Earth and the spaceship will perceive the other clock as moving slower. What if there are three clocks, one at the starting point, one on the ship, and one at the destination? Does direction of travel matter? Finally, how would the three clocks differ in the case of a round trip?

Edit: "Google it" assumes that I haven't already. I'm asking for a human to explain it because what I am reading doesn't make intuitive sense. Without an intuitive understanding, the math reads like an Abbott and Costello routine where they "proved" 7 x 13 = 28

If I'm on a spaceship headed toward the asteroid belt and I perceive the clock at my destination as moving slower, that makes sense. But if the people on the asteroid belt perceive my clock as moving slower at the same time, then which perception is proven correct when I arrive? Don't those two perceptions contradict each other?

Edit 2: While the How can time dilation be symmetrical? article is informative, it suffers from the same problem as every other article I have read: The Three Brothers don't meet up again. This is why I included the clock at the destination which agrees with the clock at the starting point. If the clock at the starting point and the clock at the destination agree, how does the clock at the destination compare to the clock on the spaceship? This is not a new question, but a clarification of the first question I asked in the first place. I realize one article said that the clock at the starting point and the clock at the destination would not agree, and it calculations would have to be done to make them agree. Let's assume for this article that the clock at the start and the destination have had those calculations done so that they do, in fact agree with each other.

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    $\begingroup$ @Yukterez I upvoted because this is a good, enquiring question - and the answer only becomes "trivial" once you have learnt it (unless you are Einstein or Minkowski). $\endgroup$
    – gandalf61
    Commented May 2 at 13:03
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    $\begingroup$ @gandalf61 - You don't have to be Einstein or Minkowski, you can also just use the search function or google for the twin paradoxon. It's all on Wikipedia, even the triplets $\endgroup$
    – Yukterez
    Commented May 2 at 13:04
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    $\begingroup$ @Yukterez That may be the case but this is still a new contributor and depending on their knowledge it may not be as straightforward to find the relevant answers e.g. not knowing the twin paradox will lead to them not finding the answer you linked. I agree that the question has been answered before and linking these answers is probably enough but that does not mean the question is trivial. $\endgroup$
    – Thomas Tappeiner
    Commented May 2 at 13:08
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    $\begingroup$ I agree that it is not trivial, but it is a duplicate. I closed it as such, although there may be other duplicates as well. If so, please add them to the list $\endgroup$
    – Dale
    Commented May 2 at 13:14
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    $\begingroup$ Re edit 2. That is already answered by vats dimri in the first duplicate: physics.stackexchange.com/q/464894 The relativity of simultaneity is not something that you can dismiss. It is the heart of the answer $\endgroup$
    – Dale
    Commented May 2 at 19:32

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