4 ms·

This stuck out to me too. Fractals teach us that infinite length can be fitted into finite area, so I'm dubious about this claim. Though I guess if we're in t

by pjz 8y ago

This stuck out to me too. Fractals teach us that infinite length can be fitted into finite area, so I'm dubious about this claim. Though I guess if we're in the realm of physics, the Planck constant determines a kind of minimum length, so the original statement may be true?

JoeAltmaier 8y ago
Pendant here: the Planck constant is simply a convenient length for all things subatomic, like a hectare or a fortnight. No minimum whatsoever implied there. Many, many things are smaller than the Planck constant.
- Koshkin 8y ago
  > the Planck constant is simply a convenient length m^2 * kg / s
- deleted 8y ago
  [deleted]
- jerf 8y ago
  "Many, many things are smaller than the Planck constant." Do we have a proof of that? Honest question. I know strings are often postulated to be smaller (by many orders of magnitude in some cases) but we are not yet particularly confident they exist. I'm not aware of us being reasonably confident that anything is smaller than Planck's size. ("Smaller than Planck's size" isn't even all that easy to define.)
  - JoeAltmaier 8y ago
    Event horizon of a black hole is many times smaller for instance.
    - chii 8y ago
      The mass of a blackhole determines the size of the event horizon. To have an event horizon smaller than the planck constant, the mass have to be also small. While theoretically possible, i don't believe this has ever been considered possible in reality - see https://en.wikipedia.org/wiki/Kugelblitz_(astrophysics) https://en.wikipedia.org/wiki/Kugelblitz_(astrophysics)
    - Florin_Andrei 8y ago
      "Smaller" in what sense? Surely not diameter. There's a known formula that gives you the diameter as a function of the BH's mass.
- kgwgk 8y ago
  You mean the Planck length (related to the Planck constant, the speed of light and the gravitational constant).
- ben509 8y ago
  > Pendant here: the Planck constant is simply a convenient length... You tipped your hand by misspelling "pedant."
phyzome 8y ago
Ideal fractals also don't exist. :-)

by pjz 8y ago

JoeAltmaier 8y ago

Pendant here: the Planck constant is simply a convenient length for all things subatomic, like a hectare or a fortnight. No minimum whatsoever implied there. Many, many things are smaller than the Planck constant.

Koshkin 8y ago
> the Planck constant is simply a convenient length m^2 * kg / s
deleted 8y ago
[deleted]
jerf 8y ago
"Many, many things are smaller than the Planck constant." Do we have a proof of that? Honest question. I know strings are often postulated to be smaller (by many orders of magnitude in some cases) but we are not yet particularly confident they exist. I'm not aware of us being reasonably confident that anything is smaller than Planck's size. ("Smaller than Planck's size" isn't even all that easy to define.)
- JoeAltmaier 8y ago
  Event horizon of a black hole is many times smaller for instance.
  - chii 8y ago
    The mass of a blackhole determines the size of the event horizon. To have an event horizon smaller than the planck constant, the mass have to be also small. While theoretically possible, i don't believe this has ever been considered possible in reality - see https://en.wikipedia.org/wiki/Kugelblitz_(astrophysics) https://en.wikipedia.org/wiki/Kugelblitz_(astrophysics)
  - Florin_Andrei 8y ago
    "Smaller" in what sense? Surely not diameter. There's a known formula that gives you the diameter as a function of the BH's mass.
kgwgk 8y ago
You mean the Planck length (related to the Planck constant, the speed of light and the gravitational constant).
ben509 8y ago
> Pendant here: the Planck constant is simply a convenient length... You tipped your hand by misspelling "pedant."

phyzome 8y ago

Ideal fractals also don't exist. :-)