Philosophy Discussion Forums

Hi everyone,

This thread is about Zeno's paradox concerning time being impossible. Zeno claimed that time cannot exist, but merely an illusion of it. The reason for the claim is Zeno's claim that for one second to pass, half of it must pass first, and half of a half of a second must pass before half a second passes, and so on and so on ad infinitum, thus he claimed that time cannot pass.

Time is number of moments that have passed. There cannot be a fraction of a moment. The smallest unit of a moment is one. The number that the number of moments increase by is one. So, if five moments have passed, it is not true that two and a half moments first passed, and one and a quarter of moments passed before that, and so on and so on. Here is how it went, one moment passed, then two moments, then three, then four and finally five.

A second is equal to X number of moments. I, at the moment do not know how many moments are a second.

I think the classical interpretation is that what you have described is the fallacy at the heart of the paradox. Space may be infinitely divisible but time is not. Otherwise you arrive at the conclusion that motion is impossible.

Yes, as per above, time is not divided in itself (things keep on changing) so the infinity is a mathematical one.

Unless you are approaching the speed of light or in a black hole, time does not compress up to a stop in that way. So, for us, after the first half second passes, so does another.

farid-A wrote: ↑November 30th, 2019, 12:55 pm Hi everyone,

This thread is about Zeno's paradox concerning time being impossible. Zeno claimed that time cannot exist, but merely an illusion of it. The reason for the claim is Zeno's claim that for one second to pass, half of it must pass first, and half of a half of a second must pass before half a second passes, and so on and so on ad infinitum, thus he claimed that time cannot pass.

I think the reason this is a false statement is because the infinite series
1/2, 1/4, 1/8, 1/16, 1/32...
is equal to 1, not infinity.

You can demonstrate this for yourself by drawing a square. Divide it in half, then divide the half on the right in half. Then divide that half in half, and continue in this manner until your pencil is thicker than the space you're dividing. What you'll notice is that you never actually need to jump outside of the box in order to include the next half.Thus, just as we would expect at a common sense level, one second divided into infinitely many halves simply equals one second. It doesn't equal an infinite amount of time.

farid-A wrote: ↑November 30th, 2019, 12:55 pm Time is number of moments that have passed. There cannot be a fraction of a moment. The smallest unit of a moment is one. The number that the number of moments increase by is one. So, if five moments have passed, it is not true that two and a half moments first passed, and one and a quarter of moments passed before that, and so on and so on. Here is how it went, one moment passed, then two moments, then three, then four and finally five.

A second is equal to X number of moments. I, at the moment do not know how many moments are a second.

I think the most logical answer would be that there are an infinite number of moments in a second--just as there are an infinite number of halves. But each half is also progressing towards being infinitely small. The moment is the conceptually actualized smallest infinite fraction.

It's a lot like saying that when you actualize [.999...] (or complete it to infinity) it is necessarily equal to 1.0. You can't really actualize [.999...], but if you could, it would necessarily have to equal [1.000...] In the same way, you can't really reach the infinitely smallest fraction, but if you could, it would be the "moment" that you speak of.

Zeno simply notes that, if you halve the interval, the distance travelled in also halved. And he carries on dividing, and the intervals and the distances carry on halving too ... and then he adds on the totally unjustified conclusion that time cannot exist. I have never worked out how this could be seen as a paradox. It's just a misunderstanding, isn't it?

You have to imagine time stopping, but as Greta said, thing keep on changing. It is something that looks prima facie plausible, and makes you think, so I guess it serves a purpose?

And time doesn't break into ever smaller divisions. It's like walking up to a wall, taking ever smaller steps. Since time has no wall, one can simply keep walking.

Well in fact the measurement of small times smaller than 10^{30} s is somewhat difficult , if time is quantizied the could be a heisenberg uncertainty principle in it.

Pantagruel wrote: ↑December 6th, 2019, 11:34 am You have to imagine time stopping, but as Greta said, thing keep on changing.

You find it plausible to imagine time being stopped, but change taking place? How?

No, for Zeno's argument, time would have to stop, but it doesn't, time is continuous.

Time isn't always continuous. For example if you take a particle that's about to decay, and you keep observing it constantly, it won't decay. So in a way, you freeze it in time as long as you want.

Atla wrote: ↑December 8th, 2019, 12:57 pm Time isn't always continuous. For example if you take a particle that's about to decay, and you keep observing it constantly, it won't decay. So in a way, you freeze it in time as long as you want.

Though this doesn't relate to Zeno's paradox, I just wrote it to be annoying.

Atla wrote: ↑December 8th, 2019, 12:57 pm Time isn't always continuous. For example if you take a particle that's about to decay, and you keep observing it constantly, it won't decay. So in a way, you freeze it in time as long as you want.

Pity that trick doesn't work with societies.

Seriously, if the decay is halted, does that mean the particle is frozen in time, or has it just temporarily stopped decaying within the flow of time (as we all aim to do in this life)?

Greta wrote: ↑December 8th, 2019, 5:06 pm

Atla wrote: ↑December 8th, 2019, 12:57 pm Time isn't always continuous. For example if you take a particle that's about to decay, and you keep observing it constantly, it won't decay. So in a way, you freeze it in time as long as you want.

Pity that trick doesn't work with societies.

Seriously, if the decay is halted, does that mean the particle is frozen in time, or has it just temporarily stopped decaying within the flow of time (as we all aim to do in this life)?

Good question, don't think anyone really knows.
It might go something like this: the system can't make the transition, can't change, as long as you/we/something is constantly observing it, the system's time-evolution is stopped. In other words, you/we/something probably keeps putting various parts of the universe in temporal stasis, as odd as that sounds. The observer lets some parts of the universe flow (mostly) normally in time, while stops/slows down/speeds up time elsewhere. But the system has to be in superposition from the observer's perspective. Yeah all this is a bit weird..

Atla wrote: ↑December 8th, 2019, 6:04 pm Good question, don't think anyone really knows.
It might go something like this: the system can't make the transition, can't change, as long as you/we/something is constantly observing it, the system's time-evolution is stopped. In other words, you/we/something probably keeps putting various parts of the universe in temporal stasis, as odd as that sounds. The observer lets some parts of the universe flow (mostly) normally in time, while stops/slows down/speeds up time elsewhere. But the system has to be in superposition from the observer's perspective. Yeah all this is a bit weird..

Actually I wouldn't be surprised at all if it turned out that our brains are exploiting these phenomena all the time. Mostly on the unconscious level. Manipulating the flow of time-evolution around you gives evolutionary advantages.