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3

Alright, here's the skinny. The universe is much much larger than 92 billion light years. But the region we can see is around that number. Also, you have it all wrong for the expansion rate of the universe. The expansion is more like stretching. No matter where you are (that's an approximation), you would see a length x expand by the same amount after a time ...


0

No. According to special relativity's postulates, the speed of light in a vacuum is the same for all observers, regardless of the motion of the light source. You may want to read the relativistic Doppler effect. It refers to the change in frequency of light due to motion of observer and/or source.


3

We can't say much about closed timelike curves with any certainty; they are an artefact of the existence of solutions to the general relativity equations which allow them. It is possible (and quite a few physicists believe this) that a theory of quantum gravity may preclude CTC from occurring, or that CTC may occur but the information might be censored by ...


2

If somehow, it is only possible to create one alcubierre drive, and it can never turn around, then you won't get closed timelike curves. Otherwise, any construction is going to have them. The reason is that you can "zoom out" far enough that the distortions to spacetime caused by the drive are no longer present, and the person flying the drive then just ...


0

You might be better off posing this question at a site geared towards Ufology. The entire concept of these beings is inconsistent with the laws of physics and is not in any way grounded in science, let alone a topic suitable for discussion on this site. First, any such ships would indeed be influenced by the gravitational field of objects around them and the ...


3

Some preliminaries: (1) Wormholes are a type of curved spacetime. Therefore there can't be any complete analysis of this problem in special relativity. You need general relativity. (2) The basic logic is not that causality violation implies FTL, it's that FTL implies causality violation. There are other reasons besides FTL why you can get causality ...


7

Ok, so let's say you had a wormhole. How long would it take to get from point A to point B using it? Let's say it's instantaneous. A traveller would arrive the same moment they left, spend some time at point B (it's really a nice place; the B-ian people are friendly and the food is great), then use the wormhole to go back to point A. No problem right? No ...


1

I like this video by MinutePhysics on this topic. It can clarify things as a primer. When you state that the universe expanded at a speed higher than the speed of light, you have to stop and ask what is actually meant by such a statement. What is moving with respect to what? In standard cosmology, we describe the universe expansion by the Hubble rate ...


2

You've completely misunderstood the impact of adding a potential to an entangled state. Atoms a and b should roughly have the same distribution ... because each single measurement of position for each entangled pair in the ensemble should yeild $x_a=x_b$ with respect to their local axes ... because this is what it means to be entangled. (Need a check ...


-2

You describe a communication protocol exploiting EPR/Bell-type setups. If I understand your protocol correctly, you envisage a 'stream' of entangled ensembles, and preagreed measurements being performed on each block of the stream to yield a 'bit'. There are various ways we could do this: you use harmonic oscillator potential. Fine. We could do the ...


0

The Transactional Interpretation of QM suggests that Maxwell's equations work backwards in time, carrying the information of one test back to the point of entanglement, where it can affect the entangled particle. This explanation bypasses any issue of violation of SR.


1

Your thought experiment does have a major flaw. According to quantum mechanics in any measurement of two spatially separated atoms a and b what happens to b has absolutely no effect at all on the probabilities of measurement outcomes on b. I'm not going to work out exactly what the flaw is in your proposed experiment, but just indicate why quantum theory ...


2

The idea is that the object generating the "pit" in the front is in the center of the flat region in the middle. What happens is that the object in the middle begins to "fall" into the "pit" in front of it, due to gravitational attraction. The "pit", however, moves forward because it is a fixed distance away from the object in the middle. Basically, as ...



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