Also, please let me know if the calculation in my first post is correct, as I am starting to think that the difference between the proper distance and the light-travel distance should play a part into it.
Ok so let's assume that ##v_{av}## is the average velocity of the entire galaxy in the radial direction as calculated from the Doppler effect. And let's say that the disc of the galaxy is contained in a plane inclined on the tangential plane (to the line of sight) with an angle ##\theta## which...
Thank you for your reply. I have thought a little about what you just mentioned and I concluded a few things, please correct me if I am wrong.
Edit: Ops, I hit post reply instead of preview. I'll continue my reply in a new post since I don't want to delete my reply.
I have read somewhere that the parallax method can be used to measure the distance to stars up to 400 light years away. I did a quick calculation and estimated that it means that our telescopes can resolve an angular movement of 8.15x10-3 arc seconds.
Taking the distance between the sun and the...
Thank you Janus, but I don't think that actually works because this model doesn't suggest that the train is symmetric relative to the observer on the platform.
But when trying to explain two beams of light on a moving object moving in opposite directions towards two mirrors it doesn't work...
I am going to talk about the famous train-platform experiment where two lightnings strike both ends of the platform and the observer on the platform is in the midpoint of the two events.
From the frame of reference of the platform, the light from event A (the one the train is moving towards)...
I can't fully understand why a person who makes a journey into space in a high-speed rocket will return home to find his age less than an identical twin who stayed on Earth. It makes since for the twin who stayed on earth, but for the twin who traveled into space, he sees himself at rest and...