Chris;
Some comments follow:
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Originally Posted by cwjohn
Firstly, the cosmic event horizon as you have named it is not 14 billion years. It is much larger than that as clearly demonstrated in the paper by Lineweaver and Davis.
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Lineweaver and Davis: “Expanding Confusion: Common Misconceptions of Cosmological Horizons and the superluminal Expansion of the Universe”, (accepted, 2003, October), paper, provides a finer detail of definition of the term ‘Cosmic Horizon’. They introduce the concept of the ‘Hubble Sphere’, the ‘Particle Horizon’ and they apply these to recessional velocites from Proper and Comoving Distance perspectives. I have no problems with adding more clarity to the definition of the ~15 billion light years I mention in my post, and refining it further, with their additions. (Ie: the ~15 billion was an estimate cited for the purposes of introducing the concept).
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Originally Posted by cwjohn
Secondly, for a moving observer this horizon would move with them, so it would not be possible that an observer pass through this horizon.
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.. as I mentioned in post #11.
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Originally Posted by cwjohn
They could pass through the cosmic event horizon of an observer on earth, but this would be of no significance whatsoever.
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It would be of no significance to the observer on the galaxy moving through the earth observer’s cosmic horizon. But the earth bound observer would most likely observe many effects as the velocity difference approaches, and exceeds, c. This topic is still hotly debated by many theorists today. I am not one of those theorists, so its not worth debating here.
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Originally Posted by cwjohn
The comparison to a black hole is like comparing apples and oranges. Completely different phenomena and completely different math.
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“The properties of cosmic horizons seem to be very similar to those of black holes. The mathematics of an accelerating, (exponentially expanding), universe imply that as things approach the cosmic horizon, we see them slow down … If we could send a thermometer attached to the end of a long cable, to the vicinity of the cosmic horizon, we would also discover that the temperature increases eventually approaching the infinite temperature at the horizon of a black hole … But our own (earth bound) observations, supplemented with some mathematical analysis, would indicate that they are approaching a region of incredible temperature.”
- Leonard Susskind, “The Black Hole War” , (page 439), originally published July 2008. (He’s spent a career on this stuff).
He goes on to say, from a theoretical perspective, there are other effects observed from the earth frame of reference. He says these depend on the theoretical flavour you choose .. Quantum Field Theory or String Theory.
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Originally Posted by cwjohn
As to the proposed experiment is it any wonder that congress is reducing funding to astronomy with this sort of nonsense taking place.
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An opinion ? .. that’s Ok .. I have ‘em too. I think its worthwhile. IMHO, regardless of the finding, the prospects of falsification or confirmation always justify the effort.
Cheers