[Golddigger (OP)]

You probably know about the Twin who traveled on a spaceship at near the speed of light, and by returning to earth faces his twin brother much older than him.

Let's say twin number 1 lives on Planet M in Galaxy Z, and twin number 2 on Planet 52 in Galaxy 998. They got there both at the same time, lets say this morning, and look exactly the same.

Planet M moves at 10,000 km/h around a star, its solar system at 20,000 km/h around the center of its Galaxy, and the Galaxy at 30,000 km/h inside the Universe.

Planet 52 moves at 0.5c around a star, its solar system at 0.6c around the center of its Galaxy, and the Galaxy at 0.7c inside the Universe.

Would 1 age faster than twin 2 for an external viewer?

[Madidus_Scientia]

Yes. Assuming the external viewer is static relative to all other parties.

[Golddigger (OP)]

Do you mean "static", as an external observer from earth? (Outside both Galaxies)

[Madidus_Scientia]

Doesn't matter where or what planet the observer is from, as long as they're static relative to both twins

[Golddigger (OP)]

Doesn't matter where or what planet the observer is from, as long as they're static relative to both twins

Am I correct assuming the observer can not be inside any solar system or even Galaxy the Twins are?

[Madidus_Scientia]

Why not?

[Golddigger (OP)]

If the observer inhabits Galaxy 998, or even the solar system of planet 52, wouldn’t that change the observers perception of the aging process of the twins, as the observer is physically  inside the same medium as twin 2, moving at almost the same speed? (Versus being in another medium or Galaxy)

[Madidus_Scientia]

Just because the observer is in the same galaxy or solar system doesn't mean they have to be moving with it. I can be inside a train travelling at 30km/ph but if I run from the front of the carraige to the back at 30km/ph then i'm still static relative to the train station.

And what medium? It's all space

[Golddigger (OP)]

Let's see if I got it right. The speed dissimilarity occurring to the twins relative to each other stays the same no matter what.

At what speed the observers planet moves is irrelevant, because the observer will always maintain the same (speed)difference relative to both twins.

Is that correct?

[Madidus_Scientia]

Yes. Sorry, My first post was probably confusing, what I meant was if the speeds you gave in the example were the speeds relative to the observer, (and the observer wasn't travelling alongside the second twin or anything) then it doesn't matter where in the universe the observer is, to them twin 1 will age faster.