# If the theory of multiple static universes is true, what about time **URL:** \ **Category:** Factual Questions\ **Created:** [July 17, 2004, 1:22pm UTC](https://boards.straightdope.com/t/if-the-theory-of-multiple-static-universes-is-true-what-about-time/255574 "2004-07-17T13:22:35Z")\ **Posts on this page:** 8\ **Page:** 1
**Author:** ![Wesley\_Clark](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/wesley_clark/32/20581_2.png) [@Wesley\_Clark](https://boards.straightdope.com/u/Wesley_Clark)\ **Post date:** [July 17, 2004, 1:22pm UTC](https://boards.straightdope.com/t/if-the-theory-of-multiple-static-universes-is-true-what-about-time/255574/1 "2004-07-17T13:22:35Z")
I was reading an article in scientific american on multiple universes, one theory is that there are endless multiple universes (level I through IV) and that within these every possible assortment of matter happens in one universe or another and that all universes are static, that we just move from one universe to another. If this is true then there has to be a unit of time which holds us in one universe then lets us move to another. It was my understanding that nobody had found a smallest unit of time and that time just kept getting smaller and smaller into smaller intervals. So how do these two contradictory things come together? How can there be static universes that we move from one to the other if there is no smallest unit of time? ---
**Author:** ![Wesley\_Clark](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/wesley_clark/32/20581_2.png) [@Wesley\_Clark](https://boards.straightdope.com/u/Wesley_Clark)\ **Post date:** [July 17, 2004, 1:31pm UTC](https://boards.straightdope.com/t/if-the-theory-of-multiple-static-universes-is-true-what-about-time/255574/2 "2004-07-17T13:31:54Z")
Also, i dont think there is a smallest unit of space either. So that doesn’t make sense either. ---
**Author:** ![Revtim](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/revtim/32/1042_2.png) [@Revtim](https://boards.straightdope.com/u/Revtim)\ **Post date:** [July 17, 2004, 2:14pm UTC](https://boards.straightdope.com/t/if-the-theory-of-multiple-static-universes-is-true-what-about-time/255574/3 "2004-07-17T14:14:22Z")
I don’t have any cites, but I’m pretty sure at least some physicists think there are indeed smallest units of time and space. I failed to come up with anything via Google, but if I find something later I’ll come back. ---
**Author:** ![Revtim](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/revtim/32/1042_2.png) [@Revtim](https://boards.straightdope.com/u/Revtim)\ **Post date:** [July 17, 2004, 4:11pm UTC](https://boards.straightdope.com/t/if-the-theory-of-multiple-static-universes-is-true-what-about-time/255574/4 "2004-07-17T16:11:49Z")
OK, here’s something: [http://www.physlink.com/Education/AskExperts/ae598.cfm](http://www.physlink.com/Education/AskExperts/ae598.cfm) > [@](#): > > The smallest unit of time (time quanta) is the time it takes for light to travel Planck’s length. (Planck’s time.) > > Since distance/relativity stop and quantum mechanics take over at Planck’s length, actions across lengths less than this boundary are meaningless. > > The fastest speed attainable is the speed of light (apparently). > > So, if we take the smallest length and divide it by the fastest speed, we get the time it takes for the fastest thing to travel the shortest distance. Times shorter than this amount simply do not make sense. > > SO: > > Planck’s length is about 1 x 10-34 m > Speed of light is about 3 x 108 m/sec > > Planck’s time is about 3.3 x 10-44 sec I’m not sure if this is an answer to the OP though. Since the “universe traversal” is a quantum mechanical event, then the fact that quantum mechanics take over at Planck’s length might not be particularly meaningful. ---
**Author:** ![Jake](https://avatars.discourse-cdn.com/v4/letter/j/f475e1/32.png) [@Jake](https://boards.straightdope.com/u/Jake)\ **Post date:** [July 17, 2004, 4:54pm UTC](https://boards.straightdope.com/t/if-the-theory-of-multiple-static-universes-is-true-what-about-time/255574/5 "2004-07-17T16:54:18Z")
My understanding of Paul Davies’ conception of multiplue universes is that the Universes themselves are timeless, but have time contained within them. _(The Mind of God, Paul Davies, Touchstone.)_ ---
**Author:** ![MikeS](https://avatars.discourse-cdn.com/v4/letter/m/919ad9/32.png) [@MikeS](https://boards.straightdope.com/u/MikeS)\ **Post date:** [July 17, 2004, 5:12pm UTC](https://boards.straightdope.com/t/if-the-theory-of-multiple-static-universes-is-true-what-about-time/255574/6 "2004-07-17T17:12:42Z")
> [@RevTim](#): > > I don’t have any cites, but I’m pretty sure at least some physicists think there are indeed smallest units of time and space. This is a little misleading. The best way to put it is that most physicists expect the laws of physics as we understand them to break down by the time you get down to such a short time scale. It could be that we actually do get space & time discreteness, as in the loop quantum gravity approach; or it could be that something more radical changes, such as particles which we normally think of as points having structure on this scale (i.e. string theory.) And, of course, it might not even be that we have to go to such small time/distance scales to see this behaviour; the idea of “large extra dimensions” has been proposed, which would (roughly speaking) modify the laws of gravity at scales of a millimeter or so while leaving all the other forces alone. (More refined experiments over the last few years have pushed the maximum scale for this particular modfication down to a nanometer or so.) But it’s not true that most (or even many) physicists expect time to move in discrete steps of 10[sup]-44[/sup] sec if and when we find a quantum theory of gravity. ---
**Author:** ![The\_Tim](https://avatars.discourse-cdn.com/v4/letter/t/ec9cab/32.png) [@The\_Tim](https://boards.straightdope.com/u/The_Tim)\ **Post date:** [July 17, 2004, 9:51pm UTC](https://boards.straightdope.com/t/if-the-theory-of-multiple-static-universes-is-true-what-about-time/255574/7 "2004-07-17T21:51:20Z")
Moving through time, especially if you conceptualize bits of time as arrangements of matter, leads to all sorts of head aches. Both _The Fabric of Reality_ and _The End of Time_ discuss the idea of timeless reality and how to think about it. The basic idea is that the perception of time is an illusion of arrangements of matter that imply a past. Smallest units of time are those intervals that when examined have sensible results, i.e. results that fit with physics. Under that unit of time things don’t work, like **MikeS** said. Since time doesn’t move in these conceptions a smallest unit of time is really the smallest amount of difference between arrangements, or something like that. ---
**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:** [July 17, 2004, 10:14pm UTC](https://boards.straightdope.com/t/if-the-theory-of-multiple-static-universes-is-true-what-about-time/255574/8 "2004-07-17T22:14:37Z")
This concept (or one very much like it) was explored in Greg Egan’s _Permutation City_, except that there weren’t multiple universes, just the one, but every possible permutation existed all at once, depending entirely on how you index it.