3 ms·

> classical physics becomes non-deterministic Is the nondeterminism very large relative to the loss of precision from quantization? Or could this just be nume

by nix0n 4y ago

> classical physics becomes non-deterministic Is the nondeterminism very large relative to the loss of precision from quantization? Or could this just be numerical imprecision? > quantum mechanics becomes non-linear I thought one of the central ideas of quantum mechanics is that space is discrete? Or am I misunderstanding what the Planck length is?

tsimionescu 4y ago
> I thought one of the central ideas of quantum mechanics is that space is discrete? Or am I misunderstanding what the Planck length is? Yes, that is a misunderstanding. The fundamental idea of quantum mechanics is that certain properties of matter are quantized, but space is not one of them - they are spin, charge, electroweak charge, color charge, and perhaps a few others. Space and time though are continuous. Planck's length comes in when we discuss the maximum precision that can be measured, as it's related to the Heisenberg uncertainty principle (and to other fundamental concepts, such as c or even black holes). So, the Planck length is the smallest unit of distance that can be meaningfully discussed, but that doesn't mean that distance between particles is an integer multiple of the Planck length.
- DontchaKnowit 4y ago
  Wow I had no idea that was the case I had the same misunderstanding as the other posted. Thank you for that, I will be revisiting my understanding of time and space
  - tsimionescu 4y ago
    I have learned a lot at this not-even-layman level from following Sabine Hossenfelder - for example, her series on the basics of Quantum Mechanics: http://backreaction.blogspot.com/2020/04/understanding-quantum-mechanics-1-its.html?m=1 http://backreaction.blogspot.com/2020/04/understanding-quant... (each blog post is also delivered in YT video form, pick whichever you prefer)

3 ms·

> classical physics becomes non-deterministic Is the nondeterminism very large relative to the loss of precision from quantization? Or could this just be nume

by nix0n 4y ago

tsimionescu 4y ago
> I thought one of the central ideas of quantum mechanics is that space is discrete? Or am I misunderstanding what the Planck length is? Yes, that is a misunderstanding. The fundamental idea of quantum mechanics is that certain properties of matter are quantized, but space is not one of them - they are spin, charge, electroweak charge, color charge, and perhaps a few others. Space and time though are continuous. Planck's length comes in when we discuss the maximum precision that can be measured, as it's related to the Heisenberg uncertainty principle (and to other fundamental concepts, such as c or even black holes). So, the Planck length is the smallest unit of distance that can be meaningfully discussed, but that doesn't mean that distance between particles is an integer multiple of the Planck length.
- DontchaKnowit 4y ago
  Wow I had no idea that was the case I had the same misunderstanding as the other posted. Thank you for that, I will be revisiting my understanding of time and space
  - tsimionescu 4y ago
    I have learned a lot at this not-even-layman level from following Sabine Hossenfelder - for example, her series on the basics of Quantum Mechanics: http://backreaction.blogspot.com/2020/04/understanding-quantum-mechanics-1-its.html?m=1 http://backreaction.blogspot.com/2020/04/understanding-quant... (each blog post is also delivered in YT video form, pick whichever you prefer)