SlightlyLeftPad
14 hours ago
Can someone explain how do we really know how fast these are moving? Our planet, our sun, our galaxy, our universe are all traveling at some speed. Do we know the velocity of all those components without out a reference point, particularly the galaxy and universe level. Is that so negligible that it doesn’t matter here?
JumpCrisscross
14 hours ago
> Do we know the velocity of all those components without out a reference point
Technically, no. “According to the principle of special relativity, all physical laws look the same in all inertial reference frames, and no inertial frame is privileged over another” [1]. The relevant reference points are usually the object being measured and the observer.
Practically, astronomers have a variety of large-scale rest frames spanning galaxies and even super clusters, none of which are relevant to the experiment this article is about.
[1] https://en.m.wikipedia.org/wiki/Inertial_frame_of_reference