Space and time interchangeable ?

Discussion in 'Free Thoughts' started by river, Jul 20, 2019.

  1. RainbowSingularity Valued Senior Member

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    rhetorical question posed as a statement of a premise to open debate
    some might call this a posit assertion of implied premise.

    are you suggesting your "how" is a question rather than a opening moot ?
     
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  3. river

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    No

    Just asking how .
     
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  5. DaveC426913 Valued Senior Member

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    You can trade travel through time for travel through space.

    You are moving through time at the greatest possible rate with reference to me (because we're stationary wrt each other).
    If you were to get in a spaceship and move away from me at 99.99% c, I would observe you to have slowed down in time by 70 times.
     
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  7. paddoboy Valued Senior Member

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    from, https://www.physicsoftheuniverse.com/topics_relativity_spacetime.html

    Another corollary of Special Relativity is is that, in effect, one person’s interval of space is another person’s interval of both time and space, and one person’s interval of time is also another person’s interval of both space and time. Thus, space and time are effectively interchangeable, and fundamentally the same thing (or at least two different sides of the same coin), an effect which becomes much more noticeable at relativistic speeds approaching the speed of light.

    Einstein's former mathematics professor, Hermann Minkowski, was perhaps the first to note this effect (and perhaps understood it even better than Einsteinhimself), and it was he who coined the phrase “space-time” to describe the interchangeability of the four dimensions. In 1908, Minkowski offered a useful analogy to help explain how four-dimensionalspace-time can appear differently to two observers in our normal three-dimensional space. He described two observers viewing a three-dimensional object from different angles, and noting that, for example, the length and width can appear different from the different viewpoints, due to what we call perspective, even though the object is clearly one and the same in three dimensions.

    The idea perhaps becomes even clearer when we consider that our picture of the Moon is actually what the Moon was like 1¼ seconds ago (the time light takes to reach the Earth from the Moon), our picture of the Sun is actually how it looked 8½ minutes ago, and by the time we see an image of Alpha Centauri, our nearest star system, it is already 4.3 years out of date. We can therefore never know what the universe is like at this very instant, and the universe is clearly not a thing that extends just in space, but in space-time

    Due to the relativistic effects of previous section can be considered an example of this: whereas the stay-at-home twin’s progress through space-time was wholly through time, the traveling twin’s progress was partly through space, so that his progress through time was less than that of the stay-at-home twin (so that he aged less).

    Therefore, as Einstein remarked, “For us physicists, the distinction between past, present and future is only an illusion, however persistent”, and these concepts really do not figure at all in Einstein’s justifiably famous formula, E = mc2, which we will look at in the next section.
     
  8. river

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    17,307

    So time needs no space !

    Light speed needs no space .

    How is this possible ?

    Explain .
     
    Last edited: Jul 28, 2019
  9. DaveC426913 Valued Senior Member

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    That does not follow from what I said.

    I can trade food for water.
    It does not follow that I "need no water".
     
  10. river

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    17,307
    So time needs space .

    Without space there is no time .
     
    Last edited: Jul 28, 2019
  11. river

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    But is the reverse true ?

    Does time create space ?
     
  12. river

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    Tough question Dave .

    But not really .
     
    Last edited: Jul 29, 2019
  13. TheFrogger Banned Valued Senior Member

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    Time is a potential that relates to the future. We only have time if we die. A prediction of the future proves the existence of time. Michael345, I will die. When I die, will you believe in time then (given that my prediction of time is correct?)
     
  14. DaveC426913 Valued Senior Member

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    18,935
    Time is simply one of the four dimensions. Three are space-like; one is time-like.

    So, you can just as easily ask river's questions like this:

    "Time needs space ."
    Length needs width.
    (In act, you need all four.)

    "Without space there is no time."
    Without length there is no width.
    (Inasmuch as you need all four, sure.)

    "Does time create space?"
    Does length create width?
    (No.)
     

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