Recent content by Arbitrageur

Thanks for the very informative answer! I accept this, and I suspected as much, which is why I tried to frame a more answerable scenario than the thread title immediately following the question, namely: So to clarify, I was considering reference frame A to be an observer on Earth's surface which...

This question needs to be framed: We track time at the Earth's surface using atomic clocks. We know that objects in orbit have clocks that run slower because of velocity and faster because of reduced gravity, and which effect is dominant depends on altitude as this illustration shows...

"The wave function describes the photon according to our own rules and math. It allows us to make predictions about photons, such as what the probability of a photon hitting a detector at a specific location is. " So, how will the predictions about the locations of the photons hitting the...

If the photon reaches the detector and its wave function collapses, obviously it was emitted. In order to be emitted, it must exit the source at some time prior to striking the detector, right?

Thanks to you and Marcus for the explanations and clarification with the example, because without it I would have also thought the distance to Andromeda might also be considered cosmological per your earlier reply. You gave me enough to research so I can figure out how to do the calculations (I...

Thanks. So roughly what would be the largest distance over which SR would be a useful approximation? any idea?

The galaxy frame sees the two receding clocks going slowly. The speed of light it will see in the receding reference frame is determined by those receding clocks. So the light is still traveling at the speed of light by traveling 100 million light years in 100 million years according to the...

You're right about length contraction. But I didn't say there would be length contraction, I said there would be time dilation. So the length doesn't contract, it just takes 50 times longer to go the same length, from the perspective of the observer outside that reference frame. They would still...

correct, inflation has nothing to do with it. Thanks for the good answer. I agree, the 13.2Gyr is sometimes referred to as "lookback time", and is not the current distance which would be ~32Glyr. qraal is correct, the distance now would be much greater, more like ~32Glyr. If you had Earth A...

Thanks, that's exactly the type of feedback I was looking for! Great! I downloaded the paper and am reading it now. I had followed the link from the article and that took me to a site where there was a fee to download the paper...next time I'll know to check arXiv, so thanks again!

"Radial motion into an Einstein-Rosen bridge" (Poplawski) Hi everyone, this is my first post on Physicsforums. I've enjoyed lurking and learning from the knowledgeable folks here. I have a question about a paper titled: "Radial motion into an Einstein-Rosen bridge," Physics Letters B, by...