We all have to start somewhere, we then (try to) move forward, and we (apparently) do. Then, in the life of every philosopher, comes the time when you get stuck or find yourself in a cul-de-sac. You want to go forward of course, it isn't possible however. So, you do what most of (would) do, make a U-turn and head back towards where you started. Along the way, you see a side-road. You have a choice now. What do you do? Perhaps the dead end you returned from was the truth, the destination, the end point of your logical journey.

Wanna see something really crazy?

A good cyclist does not need a high road. — Sherlock Holmes

But still. Time can't be stopped and space can't be cut. How can spacetime intervals exist?

But still. Time can't be stopped and space can't be cut. How can spacetime intervals exist? — EugeneW

Time can't be stopped, yup. Time, in physics, is defined with clocks in mind. Smash all the clocks, stop playing the drums, digitalize your heart and let it go thump-thumpity-thump-thump, and Chronos will die (a noble death).

Space can't be cut, true. We can bend it though, when you bend too much, you undergo mitosis.

I'm trying something. :smile:

I'm trying something. — Agent Smith

Good try! Will time still exist if we ban all clocky things, including mind clocks and hyperclocking? :chin:

A good cyclist does not need a high road. — Sherlock Holmes

Why didn't we evolve into wheel-rolling creatures?

Zeno made one big mistake. He thought the spacetime continuum could be broken up in parts. Just try break up time in pieces. Or space. It's hard. — EugeneW

His opponents thought that. He thought the world was one metaphysical thing, like Spinoza

There is also: https://en.wikipedia.org/wiki/Melissus_of_Samos

Ah yes! Thanx for the link. Indeed I read about an indestructible indivisible reality (I dont agree with changeless). So they argued from contra, so to speak?

Time can't be stopped and space can't be cut. How can spacetime intervals exist? — EugeneW

According to modern physics, motion is relative, not absolute. See:

https://www.youtube.com/watch?fbclid=IwAR1lU6DmLy6m9a1IBbs2NKx5XBaUIaBkcjQ984b_s_4O23ZX31OGYn7uAB0&v=a205YJsbBSQ&feature=youtu.be

https://www.youtube.com/watch?fbclid=IwAR0L0G064ucS76BpWhJd2rchmww1f64bu5CNooLkdBOKDB3Jk2VXvr-8_08&v=FdWMM6aXpYE&feature=youtu.be

But how can I not know the string goes around the marble if I move it around a marble? It's very tricky, but they say it's about B-time and the unified nature of the world, something both Zeno and Spinoza were getting at

Indeed I read about an indestructible indivisible reality (I dont agree with changeless). So they argued from contra, so to speak? — EugeneW

Zeno said that the world can't be infinite yet it's infinitly divisible, and it can be finite because the division of nature goes on forever. String theory and quantum loop gravity speculate about discrete pieces of space, which would solve Zeno's paradox. The conflict between general relativity with it's singularities and quantum mechanics has partially to do with this question

Observations on arrival times of distant star photons show that space is not quantified (different wavelengths show no different arrival times, which would be the case if space is quantified). How could it? What determines when the Planck time is over? If everything is frozen for a Planck time, how can it continue? I think measurable time, like distance, is limited. If spacetime is quantified, how can a particle move from A to B in the first place? Which is not to say that the metric can't be quantified, like in quantum gravity, by gravitons informing it (explaining how spacetime gets its curvature, which general relativity doesn't explain)

Zeno said that the world can't be infinite yet it's infinitly divisible, — Gregory

Didn't the Eleatic philosophers thought space is undivisible (in the link)?

Didn't the Eleatic philosophers thought space is undivisible (in the link)? — EugeneW

Yes. Zeno, Parmenides, and Mellisus thought the world one unity, one form

If spacetime is quantified, how can a particle move from A to B in the first place? — EugeneW

Quantified means discrete, right? If there is a series of discrete spaces with the spaces between them being meaningless then motion is getting stepping accross the path. But if space is infinitely divisible, then we have a distance that is finite from one point of view and infinite from another point of view. They say calculus solves this, but math has never been my strong suit

. But if space is infinitely divisible, then we have a distance that is finite from one point of view and infinite from another point of view — Gregory

An observer moving relative tò you sees your space contracted,. Space doesn't seem infinite to some.

Why didn't we evolve into wheel-rolling creatures? — EugeneW

:lol: Sabrá Mandrake!

How do you envision discrete space? Say a discrete 2d one.

As one that self loops and so stays finite. Something discrete is an infinitesimal. It infinitely gets close to zero but never reaches it. Whether this solves or merely repeats Zeno's paradox has not be settled in science

What you mean by self loops? How does a particle move in it?

Whether this solves or merely repeats Zeno's paradox has not be settled in science — Gregory

Aint the paradox resolved in science?

The theory of loop quantum gravity, along with string theory, propose that matter is not infinitely divisible but they could be wrong. I'm not a mathematician so there's only so much I know about this. Those theories want to reconcile general relativity and quantum mechanics in favor of quantum mechanics where there are discrete quanta instead of singularities

I don't think string theory quantizes gravity by quantizing space and time. Spacetime is treated classically and is treated as flat. That's called background dependent. Gravitons move in this flat space. Loop QG quantizes spacetime itself. It's kind of difficult to perceive a quantized space. That's why I asked for 2d. Or 1d even. A quantized 3d space isn't made up of small 3d cubes (or 2d squares). In LQG you often see interlocked loops but that's not how to look at it either. How can discrete time know when to move on one Planck time?

Michio Kaku says strings are one dimensional yet discrete. There is no easy way out of these issues without advanced math

Michio Kaku says strings are one dimensional yet discrete. There is no easy way out of these issues without advanced math — Gregory

He means that strings are just the same as discrete 0d particles. But 1d. Small line pieces. Ridiculous. Particles are made from 6d space of which 3 large dimensions are curled up to Planck-sized circles, an Cartesian product S1xS1xS1.