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Is time real?

  1. Jun 20, 2008 #1
    sometimes i wunder if time realy exists. just because you can use it to callculate projectil motion or whatever, is it actually a physical issue or is it just the human way to deal with a situation? do you know what i mean? what if clocks can tell your passage from the past to now but nothing actually happened in physics, only things that can age have, from diferent forms of decay. if time is not real then time travel would not be possible and alot of the physics equations would be wrong...E=MC^(2)?
  2. jcsd
  3. Jun 20, 2008 #2
    what time is it RIGHT NOW?

    or RIGHT NOW?

  4. Jun 20, 2008 #3
    if the clock was never invented you wouldn't know either. so is time a human misconception? if humans never died, would we have come to the same conclusion that there is such a thing as time?
  5. Jun 20, 2008 #4
    The idea of time as in like 6 o'clock is a human invention yes. Time as in from the Big Bang till now, and the change therein are natural.
  6. Jun 20, 2008 #5
    I think he/she means time as a 'temporal dimension' which is supposedly necessary for those changes to occur.
  7. Jun 20, 2008 #6
    "Time has come Today"

    there is no place to run
  8. Jun 21, 2008 #7


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    Humans did not invent the clock, the clock is a naturally occuring tool that humans have merely enhanced. All we did was recognize clocks in nature for what they were.

    Time is not an invention, it is a discovery. You need to learn the difference. It's the essence of science: we're not inventing the laws of nature, just discovering them. Ie, if we hadn't figured out gravity, we would still be goverened by it.
    Quite certainly no. Dying has nothing to do with anything - humans are still smart enough to recognize periodic motion when they see it (ie, the sun rising daily).

    We get this question a lot and I've never understood this prejudice against time. Perhaps you could explain it to me. Why didn't you ask: 'If the ruler was never invented, would length exist?' It's the same question.
    Last edited: Jun 21, 2008
  9. Jun 21, 2008 #8


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    Hi russ! :smile:

    But I can put a ruler in my pocket, and carry it around.

    I can't put a second in my pocket. :smile:

    (and if you find a way of doing it, I'll just reply: "but it won't be the same second!" :wink:)
  10. Jun 21, 2008 #9
    tiny-tim you're not comparing like-things. A concrete object, such as a ruler, is not comparable as an example to an intangible concept of unit measure such as a second.

    The question you'd want to pose in a fair comparison is whether or not you can place like-measurement instruments in your pocket. Ergo: can you put a watch in your pocket and carry it around the same as a ruler? And, of course, the answer is "yes".

    If you want to fairly compare trying to carry a second in your pocket to something related to measurement, then you'd ask if you could also carry an inch around in your pocket.

    Compare like ideas or objects to frame a reasonable argument. Apples to apples and etc. :smile:
    Last edited: Jun 21, 2008
  11. Jun 21, 2008 #10


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    do you have a second?

    Hi GeorginaS! :smile:

    Aren't you begging the question … or even conceding it …
    You're agreeing with me that length is "concrete" but time is "intangible" … which is the point that campal was raising and I was following.

    If time is intangible, does it "really exist", or is it something like the centre of mass of a body, which is "just the human way to deal with a situation"?

    In that sense, length (or weight) exists, but time doesn't. :smile:
    A ruler has two characteristics: it's both a measurer and a measurement (and so is a weight).

    If I have a foot rule, then I not only have a way of measuring something three feet long, say … I also have a foot!

    But if I have a clock, I only have a way of measuring seconds … I do not have a second!
    To pursue your analogy, if I have an apple that weighs a pound, then I have a pound. If I have an apple that is an inch across, then I have an inch.

    But if I have an apple … even if it's the bob of a pendulum (well, you have heard of bobbing for apples, haven't you? :biggrin:) … then I don't have a second. :smile:
  12. Jun 21, 2008 #11


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    By the same token, you can put a clock in your pocket.
    A ruler defines a centimeter just as a clock defines a second.

    Length and Time are just different facets of the underlying concept of measurement.
  13. Jun 21, 2008 #12
    I'm not conceding or agreeing with anything you're saying and, further, you're mischaracterising what I wrote. I don't know if you're playing around or if you're being serious. However, I said that a "ruler" is concrete, not that "length" is. I said that a "watch" is concrete, not that a "second" is. I compared concrete to concrete and intangible to intangible. You conflated the two and furthermore twisted what I said.

  14. Jun 21, 2008 #13
    No shes saying your trying to make the analogy of a ruler to a second and time to an inch.
    Last edited by a moderator: Jun 21, 2008
  15. Jun 21, 2008 #14
    It's time to go.
  16. Jun 21, 2008 #15


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    Maybe he does, which would explain why he's here instead of out on a date. :uhh:
  17. Jun 21, 2008 #16


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  18. Jun 21, 2008 #17
    well, there's 'rulers' , too, of a different variety, like Bush, who some people do have in their pocket, too.
  19. Jun 21, 2008 #18
    I love how rewebster avoids Russ' response.
  20. Jun 21, 2008 #19


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    Georgina was right, but only got halfway there with the explanation. You are not comparing like things - a "ruler" is a device and a "second" is a unit. Ie:

    Unit: second
    Device to measure it: watch

    Unit: meter
    Device to measure it: tape measure

    As you can see, you can quite easly carry either measuring device with you.
    Similarly, a tape measure that could only mesure one object and then be spent would be quite useless. Fortunately, stopwatches have reset buttons and tape measures are spring-loaded, so both can be used over and over again.

    In any case, yes, time and length are not exactly the same. Time has the property that it flows. But so what? That doesn't make it any less real or useful as a dimension.
    Last edited: Jun 21, 2008
  21. Jun 21, 2008 #20
    Software's intangible but it still exists.
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