The takeaway I got from the video is not that the Planck Length is a minimum distance something can move or anything about position existing on a grid of any kind. What he said was that photons that could elucidate such tiny distinctions in position would be so high in energy that they would distort spacetime to the point where "distance" loses meaning.

I thought for a moment about implications to QM if the distance between particles cannot be known exactly in any frame, and I came up with a kind of irrelevance to that kind of thing in QM. What matters is the many fields incident on a particle and the available paths (under all applicable conservation laws) that the particle can take to change its quantum state. The fields incident on the particle - or more specifically the fields interacting with the particle's wave function - may originate from other particles or their movements, but that's kind of a 2nd order association.

So did I just kick the ball down the road to what happens in the fields?
I don't think so, but it's a whole - one problem with GR and QM is that GR assumes you can know the exact position of ... well, stuff... in spacetime and QM emphatically says you cannot.

And this is right there on the boundary where QM weirdness (the Planck Length) and GR weirdness (warping of spacetime) come together in a way that causes us to scratch our heads.

I'm wondering if there are other ways to probe such a small distance, like perhaps gravity waves. I wonder how close the 2 black holes ina merger get before they merge into a single entity. I wonder if there's a way to tease anything about that out of the gravitational waves we're picking up, now.

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The factor of 2 pi comes from making an arbitrary choice of whether you choose h as a "fundamental" constant or of you choose h_bar as one. What you choose as "fundamental" constant has been under debate in the physics community for a long time. It is an arbitrary choice. We could have chosen the distance from the Earth to the Sun as a fundamental unit of length, and then the "Planck" Length would just be that distance - the juggling of numbers in the powers of fundamental constants to tease a length unit out of it would be bone simple. There would be a length unit that is considered fundamental already.

In choosing fundamental constants, you get the same units from either h or h_bar, as those only differ by a factor of 2pi. So if you choose to include either as a fundamental unit of action (this is widely regarded as an epicaly good move), then as far as the completeness of your dimension space (a math term that means you can get ANY needed unit from juggling the fundamental units) - as far as that goes, it's identical.

So you have an arbitrary choice within your game of arbitrary choices that lets you pick whether or not to include that factor of 2pi with no mathematical ramifications to the completeness of your units in your "fundamental" constants.

I've explained this to you before, and provided links to pages explaining the Buckingham Pi method of juggling numbers. You can see in that method that there is not necessarily physical meaning in that number juggling. Maybe there is, but the mere presence of a number that comes out of it being "large" or "small" is as likely coincidental.

Quote Originally Posted by OngBonga View Post
Fun fact - protons taste sour.
I saw that. I freaking love Steve Mould's YouTube channel.