# Smallest slice of time **URL:** \ **Category:** Factual Questions\ **Created:** [April 28, 2001, 3:06am UTC](https://boards.straightdope.com/t/smallest-slice-of-time/63594 "2001-04-28T03:06:50Z")\ **Posts on this page:** 20\ **Page:** 1
**Author:** ![msc75](https://avatars.discourse-cdn.com/v4/letter/m/bc79bd/32.png) [@msc75](https://boards.straightdope.com/u/msc75)\ **Post date:** [April 28, 2001, 3:06am UTC](https://boards.straightdope.com/t/smallest-slice-of-time/63594/1 "2001-04-28T03:06:50Z")
What is an “instant”? Put aside all theological arguments, and assume that God is watching all of his creation unfold. If he were to hit Pause on his VCR, what kind of time frame would be comparable to one of our seconds? In other words, what is the amount of universal activity that compromises the smallest amount of time? An atom transferring so much heat… something like that. Make any sense? ---
**Author:** ![friedo](https://avatars.discourse-cdn.com/v4/letter/f/8edcca/32.png) [@friedo](https://boards.straightdope.com/u/friedo)\ **Post date:** [April 28, 2001, 3:51am UTC](https://boards.straightdope.com/t/smallest-slice-of-time/63594/2 "2001-04-28T03:51:06Z")
Quantum theory dictates that there are discrete, indivisible units of energy and matter. Things can not be infinately small. There is the idea of “quantum time.” I dunno much about it. Perhaps Chronos or one of the other Smart People could explain it. ---
**Author:** ![Astroboy14](https://avatars.discourse-cdn.com/v4/letter/a/df705f/32.png) [@Astroboy14](https://boards.straightdope.com/u/Astroboy14)\ **Post date:** [April 28, 2001, 3:58am UTC](https://boards.straightdope.com/t/smallest-slice-of-time/63594/3 "2001-04-28T03:58:09Z")
**Astrogirl** definition: Instant (N.): 1) the amount of time between penetration and ejaculation. 2) a dissapointingly small length of time. [sup]I can’t believe I just typed that![/sup] 😃 ---
**Author:** ![Una\_Persson](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/una_persson/32/346_2.png) [@Una\_Persson](https://boards.straightdope.com/u/Una_Persson)\ **Post date:** [April 28, 2001, 4:16am UTC](https://boards.straightdope.com/t/smallest-slice-of-time/63594/4 "2001-04-28T04:16:22Z")
What you are thinking of is called Planck time. Planck time is the time it would take a photon to travel one Planck length, which is defined as 1.6x10[sup]-35[/sup] meters. Thus, Planck time is about 10[sup]-43[/sup] seconds. ---
**Author:** ![Little\_Nemo](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/little_nemo/32/3120_2.png) [@Little\_Nemo](https://boards.straightdope.com/u/Little_Nemo)\ **Post date:** [April 28, 2001, 5:12am UTC](https://boards.straightdope.com/t/smallest-slice-of-time/63594/5 "2001-04-28T05:12:36Z")
If I recall correctly, a Planck time unit is considered the smallest amount of duration possible. If two events occur within the same Planck time unit, it is not possible to determine which event occurred before the other. Therefore, any events which occur in the same Planck time unit occur simultaneously and no further division of time has any meaning. ---
**Author:** ![Bill\_H](https://avatars.discourse-cdn.com/v4/letter/b/a5b964/32.png) [@Bill\_H](https://boards.straightdope.com/u/Bill_H)\ **Post date:** [April 28, 2001, 5:58am UTC](https://boards.straightdope.com/t/smallest-slice-of-time/63594/6 "2001-04-28T05:58:54Z")
I’m going to take a wild stab here: if an object moves the smallest possible distance over the smallest possible time, is it then moving the fastest possible velocity, i.e. c? I would really like to know more about this plank time thing. Can someone post a good site? ---
**Author:** ![Enola\_Straight](https://avatars.discourse-cdn.com/v4/letter/e/dec6dc/32.png) [@Enola\_Straight](https://boards.straightdope.com/u/Enola_Straight)\ **Post date:** [April 28, 2001, 6:41am UTC](https://boards.straightdope.com/t/smallest-slice-of-time/63594/7 "2001-04-28T06:41:54Z")
Planck distance/Planck time=speed of light(Planck velocity?) ---
**Author:** ![Zarathustra](https://avatars.discourse-cdn.com/v4/letter/z/898d66/32.png) [@Zarathustra](https://boards.straightdope.com/u/Zarathustra)\ **Post date:** [April 28, 2001, 8:21am UTC](https://boards.straightdope.com/t/smallest-slice-of-time/63594/8 "2001-04-28T08:21:38Z")
So would Planck time or Planck length define the length of Achilles’s last step before he catches up with the tortoise? ---
**Author:** ![Zarathustra](https://avatars.discourse-cdn.com/v4/letter/z/898d66/32.png) [@Zarathustra](https://boards.straightdope.com/u/Zarathustra)\ **Post date:** [April 28, 2001, 8:26am UTC](https://boards.straightdope.com/t/smallest-slice-of-time/63594/9 "2001-04-28T08:26:03Z")
> [@](#): > > Suppose you have a race between Achilles and a tortoise. Now suppose that Achilles runs 10 times as fast as the tortoise and that the tortoise has a 10 meter head start at the beginning of the race. Zeno argued that in such a situation, it would take Achilles an infinite amount of time to catch the tortoise. His argument went as follows: > > By the time Achilles runs the 10 meters to the point where the tortoise began, the tortoise will have traveled one meter and will therefore still be one meter ahead of Achilles. Then, by the time Achilles covers a distance ofone meter, the tortoise will have traveled one tenth of a meter and is still ahead of Achilles. After Achilles travels one tenth of a meter, the tortoise will have traveled 1/100th of a meter. Each time Achilles reaches the previous position of the tortoise, the tortoise has reached another position ahead of Achilles. As long as it takes Achilles some amount of time to traverse the distance between the point where he is and the point where the tortoise is, the tortoise will have time to move slightly beyond that point. No matter how long the race goes on, Achilles will have to move through every point where the tortoise has been before he can pass him. Each time Achilles reaches such a point, the tortoise is at another point. Therefore, Achilles will have to pass through an infinite number of points in order to catch up with the tortoise. If it takes him some time to pass through each one of these points, it will take him forever to catch up. Is this the kind of thing the OP had in mind? ---
**Author:** ![Johanna](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/johanna/32/8318_2.png) [@Johanna](https://boards.straightdope.com/u/Johanna)\ **Post date:** [April 28, 2001, 3:10pm UTC](https://boards.straightdope.com/t/smallest-slice-of-time/63594/10 "2001-04-28T15:10:28Z")
You know the origin of the term “New York minute” as an infinitesimal unit of time? The amount of time it takes after the light turns green before the driver behind you beeps his horn. ---
**Author:** ![Colibri](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/colibri/32/1841_2.png) [@Colibri](https://boards.straightdope.com/u/Colibri)\ **Post date:** [April 28, 2001, 4:29pm UTC](https://boards.straightdope.com/t/smallest-slice-of-time/63594/11 "2001-04-28T16:29:23Z")
> [@](#): > > \*Originally posted by Jomo Mojo \* > \*\*You know the origin of the term “New York minute” as an infinitesimal unit of time? > > The amount of time it takes after the light turns green before the driver behind you beeps his horn. \*\* Here in Panama we call that unit a “panasecond.” In fact, many observations suggest the panasecond is actually a negative number. ---
**Author:** ![Chronos](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/chronos/32/134_2.png) [@Chronos](https://boards.straightdope.com/u/Chronos)\ **Post date:** [April 28, 2001, 6:43pm UTC](https://boards.straightdope.com/t/smallest-slice-of-time/63594/12 "2001-04-28T18:43:47Z")
The Planck time is not the smallest possible interval of time. It is, however, the smallest time that we have any hope of describing with anything resembling our current understanding of physics. You get the Planck time, along with the other Planck units (length, mass, energy, etc.) by combining G (Newton’s constant, describing the strength of gravity), c (Einstein’s constant, relating time and space, and which also seems to be the speed of light in vacuum), and hbar (Planck’s constant, the smallest unit of angular momentum or action). If you toss in k[sub]b[/sub] (Boltzman’s constant, relating temperature and energy) and k[sub]e[/sub] (Coulomb’s constant, which plays the same role in electrostatics that G plays in gravity), then you can also define a Planck temperature and a Planck charge. The problem with all of the Planck units (except for the Planck charge) is that they combine G, which deals with gravity, and hbar, which deals with quantum mechanics. At length scales smaller than the Planck length, or, equivalently, time scales shorter than the Planck time, both gravitational and quantum mechanical effects would be significant. However, there is currently no tested theory of physics which can successfully describe both gravitational and quantum mechanical effects, so we can’t say much about things at Planck scales. String theory and its relatives look promising, on paper, but they don’t have any experimental support as yet, and it’s not anticipated that we’ll find any any time soon. ---
**Author:** ![Zenster](https://avatars.discourse-cdn.com/v4/letter/z/cdc98d/32.png) [@Zenster](https://boards.straightdope.com/u/Zenster)\ **Post date:** [April 28, 2001, 7:53pm UTC](https://boards.straightdope.com/t/smallest-slice-of-time/63594/13 "2001-04-28T19:53:41Z")
There was a theory put forth years ago about just this sort of thing. The authors argued that time was discreet and not continuous. Their indivisible unit of time was called the Chronon and it was defined by the minimum cycle time of a computing device powered by all of the energy in the known universe. I’ve been very tempted to start a thread on this topic but will happily settle for hijacking this one with a discussion about whether time is incremental or continuous. Any takers? ---
**Author:** ![MandaJo](https://avatars.discourse-cdn.com/v4/letter/m/ac91a4/32.png) [@MandaJo](https://boards.straightdope.com/u/MandaJo)\ **Post date:** [April 28, 2001, 8:20pm UTC](https://boards.straightdope.com/t/smallest-slice-of-time/63594/14 "2001-04-28T20:20:05Z")
This may well be the inspiration for the OP, but in case anyone else missed it, Terry Prachett has a new book out _Thief Of Time_ that centers on this very idea. He desribes the smalest unit of time as the amount of time it takes for the universe to destroy and recreate itself. Which is not really valid from a physics perspective, but which makes a good book (mind you, Pratchet could make a good book out of a 2x4 and a frayed piece of string). ---
**Author:** ![Zarathustra](https://avatars.discourse-cdn.com/v4/letter/z/898d66/32.png) [@Zarathustra](https://boards.straightdope.com/u/Zarathustra)\ **Post date:** [April 28, 2001, 8:49pm UTC](https://boards.straightdope.com/t/smallest-slice-of-time/63594/15 "2001-04-28T20:49:02Z")
> [@](#): > > \*Originally posted by Manda JO \* > \*\*This may well be the inspiration for the OP, but in case anyone else missed it, Terry Prachett has a new book out _Thief Of Time_ that centers on this very idea. He desribes the smalest unit of time as the amount of time it takes for the universe to destroy and recreate itself. Which is not really valid from a physics perspective, but which makes a good book (mind you, Pratchet could make a good book out of a 2x4 and a frayed piece of string). \*\* And don’t forget that Pterry reported the discovery of faster than light particles, called “kingons”. The philosopher Ly Tin Wheedle hypothesized that since at the very moment a king dies, his eldest son then instantly becomes king _no matter how far apart these two individuals happen to be at that moment_. Ly Tin Wheedle then started on possible practical applications (torturing a small king in order to modulate the signal) but just then the bar closed. ---
**Author:** ![Zarathustra](https://avatars.discourse-cdn.com/v4/letter/z/898d66/32.png) [@Zarathustra](https://boards.straightdope.com/u/Zarathustra)\ **Post date:** [April 28, 2001, 8:51pm UTC](https://boards.straightdope.com/t/smallest-slice-of-time/63594/16 "2001-04-28T20:51:50Z")
The philosopher Ly Tin Wheedle hypothesized that **since** at the very moment a king dies, his eldest son then instantly becomes king no matter how far apart these two individuals happen to be at that moment, **there must therefore be particles transmitting this change of state at speeds even faster than light**. He called them “kingons”, or possibly “queenons”. ---
**Author:** ![dtilque](https://avatars.discourse-cdn.com/v4/letter/d/d6d6ee/32.png) [@dtilque](https://boards.straightdope.com/u/dtilque)\ **Post date:** [April 28, 2001, 10:22pm UTC](https://boards.straightdope.com/t/smallest-slice-of-time/63594/17 "2001-04-28T22:22:51Z")
> [@](#): > > \*Also sprach Zarathustra \* > He called them “kingons”, or possibly “queenons”. It seems to me that there may be a difference between kingons and queenons. Are they identical, or do the differ in mass, charge, spin or some other quantum value. And how about princeons and dukeons? It seems to me there is probably a whole family of monarchons to be experimentally explored. I think I’ll need a NSF grant … wait a minute, there’s the last call, I’ll have to explore this later. ---
**Author:** ![Yue\_Han](https://avatars.discourse-cdn.com/v4/letter/y/eada6e/32.png) [@Yue\_Han](https://boards.straightdope.com/u/Yue_Han)\ **Post date:** [April 28, 2001, 11:45pm UTC](https://boards.straightdope.com/t/smallest-slice-of-time/63594/18 "2001-04-28T23:45:03Z")
A kingon or queeon can only be destroyed if it strikes a republicon. If anyone posts Thief of Time spoilers without warning me again, _I will kill them_. No hard feelings, though, Manda. Good to see another Pratchett fan. –John ---
**Author:** ![msc75](https://avatars.discourse-cdn.com/v4/letter/m/bc79bd/32.png) [@msc75](https://boards.straightdope.com/u/msc75)\ **Post date:** [April 29, 2001, 2:07am UTC](https://boards.straightdope.com/t/smallest-slice-of-time/63594/19 "2001-04-29T02:07:49Z")
> [@](#): > > \*Originally posted by Zenster \* > \*\*There was a theory put forth years ago about just this sort of thing. The authors argued that time was discreet and not continuous. Their indivisible unit of time was called the Chronon and it was defined by the minimum cycle time of a computing device powered by all of the energy in the known universe. > > I’ve been very tempted to start a thread on this topic but will happily settle for hijacking this one with a discussion about whether time is incremental or continuous. > > Any takers? \*\* That’s an excellent question/argument. I’ve never posed that question before. I’m gonna have to go with continous, simply because we, as men, will never be able to fathom what the increments might be. ---
**Author:** ![Fern\_Forest](https://avatars.discourse-cdn.com/v4/letter/f/71c47a/32.png) [@Fern\_Forest](https://boards.straightdope.com/u/Fern_Forest)\ **Post date:** [April 29, 2001, 9:04am UTC](https://boards.straightdope.com/t/smallest-slice-of-time/63594/20 "2001-04-29T09:04:57Z")
woosh! The answer is probably in the yet to be determined category. When and if the answer comes, it will probably have a profound effect on physics. A favorite way to think about this in one of my early physics class was that if a plane was rolling down the runway and took off. And you were to pick a time reference, let’s say t = 1, and say that this was the last point in time in which the tire was in contact with the ground. Then you could not find a point in time in which tire was in the air for the first time. And vice versa. This seems to support the smooth time arguement. [Next page](https://boards.straightdope.com/t/smallest-slice-of-time/63594.md?page=2)