# What is time? **URL:** \ **Category:** Factual Questions\ **Created:** [August 8, 2007, 9:52pm UTC](https://boards.straightdope.com/t/what-is-time/414926 "2007-08-08T21:52:44Z")\ **Posts on this page:** 20\ **Page:** 1
**Author:** ![BarnOwl](https://avatars.discourse-cdn.com/v4/letter/b/e95f7d/32.png) [@BarnOwl](https://boards.straightdope.com/u/BarnOwl)\ **Post date:** [August 8, 2007, 9:52pm UTC](https://boards.straightdope.com/t/what-is-time/414926/1 "2007-08-08T21:52:44Z")
The question came up in the one philosophy class I ever took way back when, and no one seemed to know. Not even the professor. I’m talking about that whatever-it-is continuum which perhaps started when the Big Bang started. ---
**Author:** ![Mangetout](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/mangetout/32/19_2.png) [@Mangetout](https://boards.straightdope.com/u/Mangetout)\ **Post date:** [August 8, 2007, 10:00pm UTC](https://boards.straightdope.com/t/what-is-time/414926/2 "2007-08-08T22:00:46Z")
It’s the thing that stops everything happening all at once. Best explanation I’ve heard (and it might even be right, who knows), was offered by **scotth** in this thread (which is woprth reading just for the insanity of it all): > [@scotth](#): > > “(The) universe… …moves forward in time at the quantum level by a chain of handshakes between past and future. The psi-star time-reversed wave functions of (our) formulation of quantum mechanics… …represent the future reaching back to make an acommodation with the past that allows a quantum event to happen, to become reality. Each quantum event emerges into reality as a result of a feedback loop between past and future. These are allowed timelike loops that bring the universe into being.” Or, in other words, our universe is like the wave of motion in a chain of toppling dominoes - it’s not the dominoes themselves, it’s just an effect of their falling in sequence, each one triggering the next. ---
**Author:** ![BarnOwl](https://avatars.discourse-cdn.com/v4/letter/b/e95f7d/32.png) [@BarnOwl](https://boards.straightdope.com/u/BarnOwl)\ **Post date:** [August 8, 2007, 10:07pm UTC](https://boards.straightdope.com/t/what-is-time/414926/3 "2007-08-08T22:07:55Z")
[QUOTE=Mangetout] It’s the thing that stops everything happening all at once. I think I read the above quote somewhere. Best explanation I’ve heard (and it might even be right, who knows), was offered by **scotth** in this thread (which is worth reading just for the insanity of it all): Or, in other words, our universe is like the wave of motion in a chain of toppling dominoes - it’s not the dominoes themselves, it’s just an effect of their falling in sequence, each one triggering the next. [/QUOTE] The link didn’t work. I’d like to read the thread, though. ---
**Author:** ![Mangetout](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/mangetout/32/19_2.png) [@Mangetout](https://boards.straightdope.com/u/Mangetout)\ **Post date:** [August 8, 2007, 10:10pm UTC](https://boards.straightdope.com/t/what-is-time/414926/4 "2007-08-08T22:10:34Z")
Oops. > **[Question about the Space Shuttle](https://boards.straightdope.com/sdmb/showthread.php?t=140878)** > > How fast would the Space Shuttle have to reverse-orbit the Earth to turn back time like Superman did? Does NASA plan to try this in the future? When? ---
**Author:** ![Q.E.D](https://avatars.discourse-cdn.com/v4/letter/q/51bf81/32.png) [@Q.E.D](https://boards.straightdope.com/u/Q.E.D)\ **Post date:** [August 8, 2007, 10:30pm UTC](https://boards.straightdope.com/t/what-is-time/414926/5 "2007-08-08T22:30:37Z")
[QUOTE=BarnOwl] I think I read the above quote somewhere. [/QUOTE] John Wheeler. ---
**Author:** ![BarnOwl](https://avatars.discourse-cdn.com/v4/letter/b/e95f7d/32.png) [@BarnOwl](https://boards.straightdope.com/u/BarnOwl)\ **Post date:** [August 8, 2007, 10:44pm UTC](https://boards.straightdope.com/t/what-is-time/414926/6 "2007-08-08T22:44:59Z")
[QUOTE=Q.E.D.] John Wheeler. [/QUOTE] Thanks. I checked him out at Wiki, noting the books he wrote and so on. “In 1979 Wheeler spoke to the American Association for the Advancement of Science (AAAS), asking them to expel parapsychology, which had been admitted ten years earlier at the request of Margaret Mead. He called parapsychology a pseudoscience (Gardner 1981:185ff). His move was turned down and the Parapsychological Association remained a member of the AAAS.” Is parapsychology still in the AAAS? ---
**Author:** ![bonzer](https://avatars.discourse-cdn.com/v4/letter/b/45deac/32.png) [@bonzer](https://boards.straightdope.com/u/bonzer)\ **Post date:** [August 8, 2007, 11:44pm UTC](https://boards.straightdope.com/t/what-is-time/414926/7 "2007-08-08T23:44:45Z")
[QUOTE=BarnOwl] Is parapsychology still in the AAAS? [/QUOTE] [The Parapsychological Association is still an affiliate of the AAAS](http://www.aaas.org/aboutaaas/affiliates/#P) (which is what Wheeler was objecting to). ---
**Author:** ![Bosda\_Di\_Chi\_of\_Tricor](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/bosda_di_chi_of_tricor/32/16845_2.png) [@Bosda\_Di\_Chi\_of\_Tricor](https://boards.straightdope.com/u/Bosda_Di_Chi_of_Tricor)\ **Post date:** [August 8, 2007, 11:46pm UTC](https://boards.straightdope.com/t/what-is-time/414926/8 "2007-08-08T23:46:03Z")
No Time Cube references? I’m shocked. ---
**Author:** ![Mangetout](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/mangetout/32/19_2.png) [@Mangetout](https://boards.straightdope.com/u/Mangetout)\ **Post date:** [August 8, 2007, 11:49pm UTC](https://boards.straightdope.com/t/what-is-time/414926/9 "2007-08-08T23:49:04Z")
[QUOTE=Bosda Di’Chi of Tricor] I’m shocked. [/QUOTE] No, you’re educated stupid. ---
**Author:** ![Chief\_Pedant](https://avatars.discourse-cdn.com/v4/letter/c/a6a055/32.png) [@Chief\_Pedant](https://boards.straightdope.com/u/Chief_Pedant)\ **Post date:** [August 9, 2007, 12:50am UTC](https://boards.straightdope.com/t/what-is-time/414926/10 "2007-08-09T00:50:48Z")
[QUOTE=BarnOwl] The question came up in the one philosophy class I ever took way back when, and no one seemed to know. Not even the professor. I’m talking about that whatever-it-is continuum which perhaps started when the Big Bang started. [/QUOTE] Mass and energy exist in the fabric of space. The fabric of space, at present, is undefined. A given distribution is a moment in time. An alternate distribution is a different moment in time. The flow of time results from the fact that changes in the distribution of mass-energy in the matrix of space follow mathematically describable patterns. There is a debate, in general, about whether this distribution changes in discrete quanta, or in a continuum. Right now the quantum approach seems to hold sway. ---
**Author:** ![Napier](https://avatars.discourse-cdn.com/v4/letter/n/ce73a5/32.png) [@Napier](https://boards.straightdope.com/u/Napier)\ **Post date:** [August 9, 2007, 9:15pm UTC](https://boards.straightdope.com/t/what-is-time/414926/11 "2007-08-09T21:15:58Z")
I think it’s the agency that sorts causes before effects, and it only appears to be something flowing because our brains (whose function is to manipulate cause and effect) manage things with constructs we “think about”. That is, since the brain manages time for us, when we use that same brain to think about the nature of time itself, it seems like “stuff”. ---
**Author:** ![Keeve](https://avatars.discourse-cdn.com/v4/letter/k/f07891/32.png) [@Keeve](https://boards.straightdope.com/u/Keeve)\ **Post date:** [August 10, 2007, 3:05am UTC](https://boards.straightdope.com/t/what-is-time/414926/12 "2007-08-10T03:05:20Z")
[QUOTE=BarnOwl] What is time? [/QUOTE] I was going to reply with: _Well, if you tell us how you’d define space, then we can continue from there._ But **Chief Pedant** beat me to it. ---
**Author:** ![Stranger\_On\_A\_Train](https://avatars.discourse-cdn.com/v4/letter/s/13edae/32.png) [@Stranger\_On\_A\_Train](https://boards.straightdope.com/u/Stranger_On_A_Train)\ **Post date:** [August 10, 2007, 3:31am UTC](https://boards.straightdope.com/t/what-is-time/414926/13 "2007-08-10T03:31:31Z")
For a thermodynamicist, it’s the difference between which a close system is more orderly and when it becomes less orderly, or more primitively, the difference between the state when two ends of a box are at much different temperatures and when they’re closer to equilibrium. For the quantum mechanicist, it’s all about the spread of the probability distribution of the momentum and location (or two other comingled factors) of a particle. And for a child, it’s the difference between running around freely in the backyard and being forced by beastly creatures pretending to be parents to lie in bed and stare at the ceiling. It’s a useful metric to judge the rate or effect of other actions, but only in a local reference frame. Beyond that, there’s no good answer to your question; certainly not from the Philosophy department. Stranger ---
**Author:** ![dnooman](https://avatars.discourse-cdn.com/v4/letter/d/839c29/32.png) [@dnooman](https://boards.straightdope.com/u/dnooman)\ **Post date:** [August 10, 2007, 3:55am UTC](https://boards.straightdope.com/t/what-is-time/414926/14 "2007-08-10T03:55:01Z")
It’s been a while since I read [A Breif History of Time](http://en.wikipedia.org/wiki/A_Brief_History_of_Time) by Stephen Hawking, but IIRC he basically disproves the laypersons conception of time as a strict unit of measure. I couldn’t find a link with quotes, nor do I own the book, but I think it’s a great book for anyone to own regardless of their level of scientific knowledge. ---
**Author:** ![Frylock](https://avatars.discourse-cdn.com/v4/letter/f/ce7236/32.png) [@Frylock](https://boards.straightdope.com/u/Frylock)\ **Post date:** [August 10, 2007, 5:08am UTC](https://boards.straightdope.com/t/what-is-time/414926/15 "2007-08-10T05:08:40Z")
[QUOTE=Stranger On A Train] Beyond that, there’s no good answer to your question; certainly not from the Philosophy department. Stranger [/QUOTE] On the contrary, there are several good answers (or at least, thoughts potentially contributing to a good answer) from the Philosophy department. For the curious, some of them may be contained at the following link: [Time (Stanford Encyclopedia of Philosophy)](http://plato.stanford.edu/entries/time/) 😉 -FrL- ---
**Author:** ![Nancarrow](https://avatars.discourse-cdn.com/v4/letter/n/c37758/32.png) [@Nancarrow](https://boards.straightdope.com/u/Nancarrow)\ **Post date:** [August 10, 2007, 10:02am UTC](https://boards.straightdope.com/t/what-is-time/414926/16 "2007-08-10T10:02:52Z")
It’s what you measure with a clock. ---
**Author:** ![Kozmik](https://avatars.discourse-cdn.com/v4/letter/k/8dc957/32.png) [@Kozmik](https://boards.straightdope.com/u/Kozmik)\ **Post date:** [August 10, 2007, 10:24am UTC](https://boards.straightdope.com/t/what-is-time/414926/17 "2007-08-10T10:24:52Z")
Think of this aspect of time: relations of events to each other Time allows things to _not_ happen all at once. For example, in the news, the highway bridge collapse, the mine incident, the New York City tornado - all happened on roughly the same day. Of course, there is no reason why they could not happen on different days. The point is that there is a finite number of ‘events’ that don’t happen on the same day…say, a million events, similar to the bridge collapse or the tornado, could not happen on the same day. ---
**Author:** ![BarnOwl](https://avatars.discourse-cdn.com/v4/letter/b/e95f7d/32.png) [@BarnOwl](https://boards.straightdope.com/u/BarnOwl)\ **Post date:** [August 10, 2007, 12:33pm UTC](https://boards.straightdope.com/t/what-is-time/414926/18 "2007-08-10T12:33:40Z")
[QUOTE=Kozmik] Think of this aspect of time: relations of events to each other Time allows things to _not_ happen all at once. For example, in the news, the highway bridge collapse, the mine incident, the New York City tornado - all happened on roughly the same day. Of course, there is no reason why they could not happen on different days. The point is that there are a finite number of ‘events’ that don’t happen on the same day…say, a million events, similar to the bridge collapse or the tornado, could not happen on the same day. [/QUOTE] But is that a function of time or mere probability? I wonder if John Wheeler fired off his famous statement in jest - “Time keeps things from happening all at once” (or words to that effect). Time — whatever it is — doesn’t DO anything. Time is just there and in some baffllingly impassive way, it enables shit to happen totally independent of it. Except that if time stopped, all events would stop, too. Time somehow enables change, but doesn’t control change; it doesn’t limit how many events that can happen in a given span. I think. ---
**Author:** ![Bosda\_Di\_Chi\_of\_Tricor](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/bosda_di_chi_of_tricor/32/16845_2.png) [@Bosda\_Di\_Chi\_of\_Tricor](https://boards.straightdope.com/u/Bosda_Di_Chi_of_Tricor)\ **Post date:** [August 10, 2007, 9:16pm UTC](https://boards.straightdope.com/t/what-is-time/414926/19 "2007-08-10T21:16:12Z")
Time is 4:16 PM, Central Daylight, at posting ---
**Author:** ![sturmhauke](https://avatars.discourse-cdn.com/v4/letter/s/e47c2d/32.png) [@sturmhauke](https://boards.straightdope.com/u/sturmhauke)\ **Post date:** [August 10, 2007, 9:29pm UTC](https://boards.straightdope.com/t/what-is-time/414926/20 "2007-08-10T21:29:09Z")
Centimeters measure the physical distance between objects. Likewise, seconds measure the temporal distance between events. Time is only another dimension, just one that we perceive differently. If you really want to twist your noodle, think about the fact that inside a [black hole](http://www.daviddarling.info/encyclopedia/K/Kerr_black_hole.html), timelike dimensions become spacelike dimensions and vice versa. [Next page](https://boards.straightdope.com/t/what-is-time/414926.md?page=2)