Recent content by peterraymond

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    Ghosting

    Ghosting
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    I Why didn't the Big Bang form a Black Hole?

    Thanks for the replies. It did seem like it would be a FAQ - I just hadn't seen it. My "(pop science)" label was included not to say I had learned something from pop science, but just a warning that that was the level of the questioner. One part of the answer leads naturally to another...
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    I Why didn't the Big Bang form a Black Hole?

    (pop science) It seems like the mass in the universe at the point of origin was way higher and the size way smaller than required to form a black hole, so why didn't our universe just sit forever as a single black hole? From a figure for the mass of the universe you could calculate the event...
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    B Does this thought experiment show that Space must be curved?

    I'm only on chapter 3 in the reading and it supports the idea that you need to understand the foundations and proceed step by step from there. Otherwise it's like trying to skip addition and go straight to multiplication. Having admitted that and using a term I certainly don't fully understand...
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    B Does this thought experiment show that Space must be curved?

    I did go to: https://www.physicsforums.com/threads/the-bending-of-starlight-is-twice-the-Newtonian-prediction.1003623/ If you want relatively simple facts you can find them on the internet. If you want to understand something more complicated you need a book. That's what I need. I believe...
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    B Does this thought experiment show that Space must be curved?

    I realized before I wrote that my photon gun is impossible and tried to indicate that. You can determine statistically the probability of a photon landing in different places, but you can't contrain it to land in any particular one. You could in theory use a large telescope to send a large...
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    B Does this thought experiment show that Space must be curved?

    I assume that the path of photons would curve in this experiment in the presence of gravity, but that Newtonian mechanics would predict no deflection. My experiment though clearly has the problem that it would be virtually impossible to conduct. Unlike Eddington's observations.
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    B Does this thought experiment show that Space must be curved?

    I'm hoping this is basic and obvious, but assume it's not to the general public. Ignore quantum mechanics and diffraction and assume a gun that can fire photons that each hit the center of a remote target. Place one of these and a conventional gun that shoots bullets at 1000 m/sec inside of a...
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    I What if the Universe expands faster than the speed of light?

    I'll say and/or admit a few things. To hopefully simplify the answer my special relativity question was intentionally posed so that things like expansion of the universe and gravity were excluded. It's actually great that even special is more complicated than my mental model. I guess I'm...
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    I What if the Universe expands faster than the speed of light?

    When I said each observer has their own space-time, I see I used the wrong words, but I was just trying to say that everyone appears stationary to themselves. Davis - Lineweaver, have a Scientific American article that is more approachable and can be found outside the daunting SA paywall at...
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    I What if the Universe expands faster than the speed of light?

    Thanks for the responses and references. I haven't gotten very far yet and am not making any statement with confidence. I skimmed Wikipedia on red shift and found a source for the highest observed red shifts that documents relative motion of much more than C. It seems like a key concept is...
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    I What if the Universe expands faster than the speed of light?

    I'm not surprised that my questions were as clueless as I suspected they might be. I'd guess a typical result from trying to extrapolate from what one reads in pop-science. It is nice that the answers aren't clueless. In some forums the people answering frequently know no more than the people...
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    I What if the Universe expands faster than the speed of light?

    I may be way off, but at some point in the past I understand there was super expansion where the universe expanded faster than the speed of light. If matter expanded with it it's an example of matter in separate areas moving apart faster than the speed of light. If it didn't the universe has...
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