3 ms·

I would be surprised if it is not, given the success of spacetime treating it as just another dimension.

wetmore 5y ago
What does that have to do with it being discrete?
SideburnsOfDoom 5y ago
"A Planck time unit is the time required for light to travel a distance of 1 Planck length in a vacuum" https://en.wikipedia.org/wiki/Planck_units#Planck_time_and_length https://en.wikipedia.org/wiki/Planck_units#Planck_time_and_l...
nine_k 5y ago
I don't know about any experimental proofs that either time or space is definitely discrete, or definitely continuous. Both Planck length and Planck time are way too short for current experimental techniques.
- sweetheart 5y ago
  Slightly unrelated but your comment led me to actually learning what the Planck length is, and the Wikipedia article for it has a great section on how to visualize it [1]. Figured others might enjoy this! 1. https://en.wikipedia.org/wiki/Planck_length#Visualisation https://en.wikipedia.org/wiki/Planck_length#Visualisation
baja_blast 5y ago
I am unconvinced that time is a real dimension, sure we can model movement/interactions of particles as a 4th dimension, but nothing in our understanding of physics requires it being a physical reality. IMO it's less space-time and more just space, it's just the rate of change slows with more mass.
- jhayward 5y ago
  There's at least one prominent physicist [1] who is working on showing that time is an emergent property of quantum physics rather than a fundamental one. [1] https://www.preposterousuniverse.com/blog/2013/10/18/is-time-real/ https://www.preposterousuniverse.com/blog/2013/10/18/is-time...
- AnimalMuppet 5y ago
  If time isn't real, then when you say "rate of change", I ask "rate of change with respect to what?"
  - advanced-DnD 5y ago
    He's not claiming time isn't real, which the definition of "real" is difficult and troubling to define in itself. I think he doesn't consider time to be 4th (or part of 3+1 or \R^3 \times \R ) dimension... or in heat equation language: that the domain is a not parabolic cylinder.
  - sweetheart 5y ago
    Check out "The Order of Time" by Carlo Rovelli! You might find it interesting. He explains (WAY more eloquently than I could) that time is most likely an interpretation of underlying physical law, rather than a fundamental part of it! An illusion, if just a fancy one.
    - AnimalMuppet 5y ago
      I have a hard time buying that, given the Lorentz Transform. Time is just as much a real dimension as space is. (Or are the dimensions of space also "an interpretation of underlying physical law"?) I believe the Lorentz Transformation more than I believe eloquent arguments.

What does that have to do with it being discrete?

"A Planck time unit is the time required for light to travel a distance of 1 Planck length in a vacuum" https://en.wikipedia.org/wiki/Planck_units#Planck_time_and_length https://en.wikipedia.org/wiki/Planck_units#Planck_time_and_l...

nine_k 5y ago

I don't know about any experimental proofs that either time or space is definitely discrete, or definitely continuous. Both Planck length and Planck time are way too short for current experimental techniques.

sweetheart 5y ago
Slightly unrelated but your comment led me to actually learning what the Planck length is, and the Wikipedia article for it has a great section on how to visualize it [1]. Figured others might enjoy this! 1. https://en.wikipedia.org/wiki/Planck_length#Visualisation https://en.wikipedia.org/wiki/Planck_length#Visualisation

baja_blast 5y ago

I am unconvinced that time is a real dimension, sure we can model movement/interactions of particles as a 4th dimension, but nothing in our understanding of physics requires it being a physical reality. IMO it's less space-time and more just space, it's just the rate of change slows with more mass.

jhayward 5y ago
There's at least one prominent physicist [1] who is working on showing that time is an emergent property of quantum physics rather than a fundamental one. [1] https://www.preposterousuniverse.com/blog/2013/10/18/is-time-real/ https://www.preposterousuniverse.com/blog/2013/10/18/is-time...
AnimalMuppet 5y ago
If time isn't real, then when you say "rate of change", I ask "rate of change with respect to what?"
- advanced-DnD 5y ago
  He's not claiming time isn't real, which the definition of "real" is difficult and troubling to define in itself. I think he doesn't consider time to be 4th (or part of 3+1 or \R^3 \times \R ) dimension... or in heat equation language: that the domain is a not parabolic cylinder.
- sweetheart 5y ago
  Check out "The Order of Time" by Carlo Rovelli! You might find it interesting. He explains (WAY more eloquently than I could) that time is most likely an interpretation of underlying physical law, rather than a fundamental part of it! An illusion, if just a fancy one.
  - AnimalMuppet 5y ago
    I have a hard time buying that, given the Lorentz Transform. Time is just as much a real dimension as space is. (Or are the dimensions of space also "an interpretation of underlying physical law"?) I believe the Lorentz Transformation more than I believe eloquent arguments.