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Thread: Question about time...

  1. #61
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    Time is distance divided by speed.

  2. #62
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    If you are reading this thread, then you need to read this web page:

    http://www.pitt.edu/~jdnorton/Goodies/What_is_time/

    His answer to that question includes my own, which I'll state in my
    own words: A definition or explanation describes an unfamiliar thing
    in terms of things that are familiar. Time is familiar to everyone.
    We all experience it all the time. Nothing that is in any way similar
    to time is as familiar to us as time is. So it is not possible to define
    or explain or describe time in terms of things that are more familiar.
    Time is one of those things that can only be understood through
    experience. Like color, amusement, happiness, or love.

    The quote from book 11 of Augustine's 'Confessions':

    https://harpers.org/blog/2009/03/aug...ality-of-time/

    -- Jeff, in Minneapolis
    http://www.FreeMars.org/jeff/

    "I find astronomy very interesting, but I wouldn't if I thought we
    were just going to sit here and look." -- "Van Rijn"

    "The other planets? Well, they just happen to be there, but the
    point of rockets is to explore them!" -- Kai Yeves

  3. #63
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    Quote Originally Posted by Jeff Root View Post
    If you are reading this thread, then you need to read this web page:

    http://www.pitt.edu/~jdnorton/Goodies/What_is_time/

    His answer to that question includes my own, which I'll state in my
    own words: A definition or explanation describes an unfamiliar thing
    in terms of things that are familiar. Time is familiar to everyone.
    We all experience it all the time. Nothing that is in any way similar
    to time is as familiar to us as time is. So it is not possible to define
    or explain or describe time in terms of things that are more familiar.
    Time is one of those things that can only be understood through
    experience. Like color, amusement, happiness, or love.

    The quote from book 11 of Augustine's 'Confessions':

    https://harpers.org/blog/2009/03/aug...ality-of-time/

    -- Jeff, in Minneapolis
    Yet that answer is not a scientific one, as it is not the scientist's goal to prejudge time, but rather to test it. In science, we can only allow operational definitions, which do not look like "I know it when I see it," as that dictates to nature. Instead, operational definitions look like instructions for doing a quantitative measurement, which allows nature to talk to us instead. So in science, time is something that can be measured with a clock, and although the clock is something we know when we see (it is something that exhibits the necessary consistencies that allow time to be a scientific notion in the first place), time itself is not something we know when we see. Indeed, the concept of time used in relativity is not at all like anything we've seen. No doubt St. Augustine would have been quite shocked by how time "actually works," which is more or less the reason we had to invent science in the first place!

    Hence, whenever one asks "what is time," one can mean a lot of things. One can mean, "what is time in science," and that's a very different question from "what is the notion of time that I think I know already from my daily life." Indeed, in science, the latter question really doesn't make any sense, even if one imagines it does, but of course science need not be all things to all people. Many people think they already know the Earth is flat, for example, and they don't think they need science to tell them otherwise. They are not listening anyway.

    The philosopher you quote felt that the scientific definition of time, that which a clock measures, is insufficient to answer what is time, but actually I think a very good answer is this: "time is our name for the recognition that it is possible to have clocks." It is because the concept of a clock makes sense and the engineering of a clock is straightforward that we have a notion of time, and any and all precision that comes with that notion stems from clock precision, whereas all informal elements stem from more informal versions of clocks. It is an observation about clocks, that's what the time concept is, and like so many scientific concepts, once defined, we discover it is way different than we imagined when we look at it more closely. This is the key fact that "I know it when I see it" thinking misses, although one also needs a version more of that ilk to cover all the unscientific needs for the notion. It is always a choice to think scientifically, and it is always necessary to notice if that choice is being made-- or not.
    Last edited by Ken G; 2017-Dec-10 at 04:25 AM.

  4. #64
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    No matter how time is defined, one thing is common: it moves forward, not backward. That is why the question arises: How did we get to the present?

  5. #65
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    As far as I can tell time is events recorded relative to the number of revolutions of a periodic object. One revolution can define an interval, but that is all that we are saying. 1000 intervals, a zillion intervals etc. It has no absolute meaning.
    The moment an instant lasted forever, we were destined for the leading edge of eternity.

  6. #66
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    Quote Originally Posted by gzhpcu View Post
    No matter how time is defined, one thing is common: it moves forward, not backward. That is why the question arises: How did we get to the present?
    I was trying to address that in post 34. Iím afraid I canít give you anything more satisfying, but do you see the point?
    As above, so below

  7. #67
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    Quote Originally Posted by gzhpcu View Post
    No matter how time is defined, one thing is common: it moves forward, not backward. That is why the question arises: How did we get to the present?
    If you want to take that line, then I do not see your problem. your time has moved forward from the past to now. Yesterday is passed, today is the present. But you are not right about "however it is defined" . "How did we get to the present? is a question full of assumptions as has been teased out already.
    sicut vis videre esto
    When we realize that patterns don't exist in the universe, they are a template that we hold to the universe to make sense of it, it all makes a lot more sense.
    Originally Posted by Ken G

  8. #68
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    Quote Originally Posted by gzhpcu View Post
    No matter how time is defined, one thing is common: it moves forward, not backward. That is why the question arises: How did we get to the present?
    Common in what sense? To all humans? To all sapient species, including potential aliens? To all physical systems? And what is "it": Does time move around us, or do physical objects move through time? And what do you mean by defined: How it is designed/evolved to work, how it is observed to work, or how it is explained/theorized to work? And when you say backwards, you you mean an unwinding of cause-effect, or moving forward in an opposite direction?

    Is there something you think is unique about the present? Even on an infinite plane, a finite object takes up a finite area. It has to be somewhere. Is the issue more a Cognitive Dissonance between human ego and the Copernican Principle?
    Et tu BAUT? Quantum mutatus ab illo.

  9. #69
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    Quote Originally Posted by Ara Pacis View Post
    Common in what sense? To all humans? To all sapient species, including potential aliens? To all physical systems? And what is "it": Does time move around us, or do physical objects move through time? And what do you mean by defined: How it is designed/evolved to work, how it is observed to work, or how it is explained/theorized to work? And when you say backwards, you you mean an unwinding of cause-effect, or moving forward in an opposite direction?

    Is there something you think is unique about the present? Even on an infinite plane, a finite object takes up a finite area. It has to be somewhere. Is the issue more a Cognitive Dissonance between human ego and the Copernican Principle?
    Time moves forward. Forget theories on exotic oarticles. The present is a moving target, but it moves forward on the macro level. What is pertinent is what affects us. Sure you could have a model of slices of spacetime layered upon one another. Why so complicated? What is pertinent to us is how we experience it. Abstract mathematical models are fine, but they do not neccesarily reflect what things really are. They are models to use to make predictions and need not be taken literally.

  10. #70
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    Time is what makes me either bored or late for something.

  11. #71
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    Quote Originally Posted by gzhpcu View Post
    Isn't Planck time the time needed to cross the Planck length, so defacto the smallest time measurement possible?
    But, the Planck mass is a small insect egg, about a fiftieth of a milligram. I'm not sure you can say anything is the smallest possible.

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