Can a Universe with a Lone Star Survive without an Absorber?

[Jilang]

I have been reading today about the Wheeler-Feymann absorber theory and it occurred to me that it there was no absorber there would be no emission. What would this mean for a universe that has only one star? Would it be able to rid itself of energy or not?

 

[DrChinese]

I have discussed this with a number of others here. They felt that this situation would not occur, ie that there would be no suppression of light emission into free space.

I am not so sure that all interpretations would say the same thing. Specifically: if we live in an accelerating and expanding universe, the Milky Way will eventually become a lonely galaxy. Even now, there are substantial volumes of space which cannot ever receive light we send out today because it is receding faster than a critical amount.

I personally believe that an experiment can demonstrate that to be either true or false. I might bet on a null result, but who knows?

 

[DrChinese]

The experiment would be as follows: Alice and Bob each receive an entangled photon, and each has a beam splitter and detectors oriented such that:

Alice's Detector 1 goes off with Bob's Detector 1
Alice's Detector 2 goes off with Bob's Detector 2
Bob's 2 detectors go off equally often.

If Alice re-routes her Detector 1 stream* instead to far deep space (where it can never be absorbed), then Bob's Detector 1 cannot go off in those cases (due to conservation considerations). A change in the ratio of clicks at Bob's 1 and 2 detectors would be evident. That is because Detector 1 would click less than before.

Now keep in mind that were this analysis correct, you could also perform FTL signalling from Alice to Bob. So that is a strong indicator that a null result would be forthcoming.


*And this stream is obviously no longer going to Detector 1.

 

[Jilang]

Thank you. I would imagine that aiming them exactly into a void region would be highly problematic. Is there any other way to prevent a photon being absorbed?