Does time exist?

Discussion in 'Pseudoscience' started by Asexperia, Sep 28, 2015.

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  1. whynwhynwhy Registered Member

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    1. And 2. Both reality and illusion.

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  3. BdS Registered Senior Member

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    What part does space play in what stops everything from happening at once?

    It is interesting though.

    So can I say, Time is the current coordinates of all the masses in the “now” space environment?

    Motion? Or, is time a property of motion?
    Location? Or, is time a property of location?


    A created concept that’s naming a physical thing “Space” and it has “distance” another concept... but the concepts are still describing physical things/measurements no matter what you refer to the physical with. The physical still exists without our conjured concepts?
     
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  5. Michael 345 New year. PRESENT is 70 years old Valued Senior Member

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    Well everything does happen at once in a Universal NOW

    Space stops it happening in a single location

    The stuff we look from the Mars Rovers happened, for us, at a previous NOW. But the distance between Earth and Mars and the speed of light limitations carrying the information to us splits our NOW from any Mars NOW

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  7. James R Just this guy, you know? Staff Member

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    No. There is no universal NOW, as I have explained.

    Why do you insist on using bizarre language like that? Why not just say that the stuff we look at from the Mars Rover happened in our past?

    No. Not fundamentally. If Mars was actually stationary with respect to the Earth, we'd be in the same frame of reference, regardless of how far away Mars was.

    You're making a common mistake that beginners in relativity often make, in confusing signalling delays for reference frame effects. The relativity of simultaneity, for instance, has nothing to do with signalling delays or light travel time.

    Let me know when you stop knowing everything and are ready to learn something.
     
    Last edited: Jan 7, 2020
  8. James R Just this guy, you know? Staff Member

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    No. The main problem is that its impossible to specify a unique "now" environment. One of Michael 345's stumbling blocks in that he is unaware of this. That's far from the most serious problem for him, however.

    By "motion" people usually have in mind something that involves speed. Speed is distance covered per unit time. The concept of speed is defined with reference to time; it assumes there is time.

    (How could we possibly talk about motion in the absence of time?)
     
  9. Michael 345 New year. PRESENT is 70 years old Valued Senior Member

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  10. Q-reeus Valued Senior Member

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    Not true at all. For a given relative velocity, the degree of nonsimultaneity (as opposed to its mere existence as phenomenon) is directly proportional to the relative displacement along the relative motion axis.
    Thus has to involve signal delay (light travel time is a redundancy). See e.g. this Wikipedia illustration of AE's train thought experiment:
    https://upload.wikimedia.org/wikipedia/commons/9/96/Einstein_train_relativity_of_simultaneity.png
    The longer the carriage, the greater the degree of nonsimultaneity - obviously.
     
  11. James R Just this guy, you know? Staff Member

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    You're mistaken.

    You haven't specified any particular events that you're referring to here, so it's hard to know what you're trying to say.

    Relativity of simultaneity (let's stick with special relativity for now) depends only on the relative speed of the two reference frames involved. It does not in any way depend on whether there are any signals propagating from one place to another through spacetime or how fast they do that.
     
  12. James R Just this guy, you know? Staff Member

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    34,678
    Again, you posted the same article in the previous thread, did you not? Like I said, it seems you have nothing new to add to our previous discussion.

    I'll settle for pointing out two errors in the article: one from Rovelli, and one from the writer of the piece.

    In fact, in the reference frame of the "present here", there is one and only one "special moment" at Proxima b that would share the same time coordinate as "now" here.

    Of course, an observer flying through space somewhere else would not necessarily say that the "present here" on Earth and that "special moment" on Proxima b happened simultaneously in his or her frame of reference. Maybe that was the point that Rovelli was making and he didn't express it clearly, or the part that was quoted was taken out of context. Otherwise, Rovelli is just wrong about this.

    This is the journalist's error.

    The fact that the person in London and the person in New York are experiencing different daylight conditions doesn't mean they don't share "the same time". A time zone is not time. Time zones on Earth are just a convenience; they don't tell us anything fundamental about time itself.

    If you drop a glass and it breaks at some instant in London, there will be one unique instant in New York at which that glass broke, too. The fact that it happened at 12 noon in the London time zone, when that instant was labelled as 7 am in New York is irrelevant.
     
  13. Q-reeus Valued Senior Member

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    3,692
    Someone is for sure.
    I gave a Wikipedia link. Check it out this time.
    You're out on a limb again. When observer A in frame S has zero relative displacement along the relative velocity axis to observer B in frame S', there is zero nonsimultaneity, regardless of relative speed. That is basic! The formula for time transformation makes it explicit e.g. Section 3.1, eqn (3.1) here:
    https://users.physics.ox.ac.uk/~smithb/website/coursenotes/rel_A.pdf
    The inverse transformation is shown in eqn (3.5)
    Need help interpreting that simple expression? If x there is zero, we have a broadside situation and there is zero nonsimultaneity, even though relative clock rates are different. Savvy?
    AE established the principle of nonsimultaneity based on signal propagations. Again - go back and actually look at that Wikipedia ref I linked to earlier.
    And btw, re that in red, it very much depends on 'how fast they do that'. In a Newtonian universe c is infinite and nonsimultaneity would not exist, as eqn (3.1) makes obvious.
     
  14. DaveC426913 Valued Senior Member

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    So, Michael - after claiming many times there is no such thing as the past - acknowledges the past.

    And of course, has to rename it.

    This is dumb Michael, you're contradicting your own assertions.
     
  15. James R Just this guy, you know? Staff Member

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    You're repeating yourself. We already agreed that one of us is mistaken. I think it's you again.

    There was no need. I went back and checked it, just in case, and it was what I expected it would be.

    Nope.

    You're talking about two events that happen at the same place, there. If such events are simultaneous in one frame, they are simultaneous in every frame. Is that all you're saying? How is that relevant to anything I wrote?

    No. Do you?

    How is this relevant to anything I wrote?

    At least you've narrowed down your supposed objection to a specific pair of events now, even if you are confusing events with observers. Anyway, it's a non-issue.

    Maybe, maybe not. Does it matter how he established it?

    Why? Nothing you have said impacts on what I wrote.

    No. The same argument about signalling delays would apply to sound waves or any other kind of wave. It wouldn't need to depend on the speed of light.

    The problem you're having here lies in your misconception that the relativity of simultaneity somehow involves light signals travelling from one place to another. It doesn't. Signalling delays might add on some time delay to when an observer located somewhere observes light or some other signal from an event occurring at a distance, but that effect has nothing to do with relativity, per se.

    How about you step down from your high horse for a while? I think he's getting tired. Turn over a new leaf for 2020. Be a nicer person. Give it a try and you might find yourself being less grumpy all the time.
     
  16. origin Heading towards oblivion Valued Senior Member

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    Do you think the time delay between seeing a lightening strike and hearing the thunder is an example of simultaneity?
     
  17. Q-reeus Valued Senior Member

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    You presume I am somehow 'grumpy' for taking you to task for propagating error(s) here. The slippery eel who's ego won't allow admitting error.
    Instead covering it up with obfuscation, and no doubt expecting fawning supporters to come in to help out or so they think. So deja vu:
    http://www.sciforums.com/threads/traveling-toward-a-light-source.160434/

    I never claimed light signals had to be specifically manifested in a given instance of nonsimultaneity - that was your insinuation. Yet signal delay, at light speed, is integral to how the concept was established - I'm repeating that here. Doesn't seem to be getting through.
     
  18. Q-reeus Valued Senior Member

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    Well it's clear from your wording you think it's an example of nonsimultaneity. No. It's an example of signal delay (differential signal delay to be precise). Nonsimultaneity in the relativistic sense has to also involve relative velocity v AND separation along the axis of v. To repeat yet again.
    And btw it was you that never had the decency to come back and admit your basic error in post #2 of that thread linked to last post.
     
    Last edited: Jan 8, 2020
  19. origin Heading towards oblivion Valued Senior Member

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    11,078
    Oh, I forgot this is some sort of contest for you, I was incorrect, in post #2. I thought that was clear as the thread progressed.
    Thank God we have cleared that up!
     
  20. Q-reeus Valued Senior Member

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    3,692
    Not a contest - I just deduced your previous post was a support exercise meant to get James R off the hook. Instead, it backfired.
    Do you admit that your lightening case in #2193 is NOT an example of relativistic nonsimultaneity, as you obviously thought it was?
     
  21. DaveC426913 Valued Senior Member

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    14,686
    For Pete's Sake...

    It's lightning. Not lightening.

    Maybe there should be a little less throwing stones from glass houses...
     
  22. Asexperia Valued Senior Member

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    That's a contradiction. Can you explain it?

    We observe duration for the experience including time that is the regular duration (objective). The period or interval of time is imperceptible, so time is magnitive.
     
  23. Q-reeus Valued Senior Member

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    3,692
    And you actually think a simple spelling error is somehow worthy of a 'throwing stones in a glasshouse' tut tut - your attempt at a support effort for James R.
    Hahaha - actually you forgot to check where that spelling error started here. Hint - go read #2193. You are unwittingly condemning a buddy! Fancy that.
    All I did was copy his spelling. In retrospect a fool thing to do. But tell me, what does my 'sin' in doing that have anything whatsoever to do with the actual issues?
    Nothing of course. So if you don't want to look like a cheap shot idiot, actually contribute to the physics issues in contention.
     
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