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drdeca | 12 days ago

Hm, I think you are taking the language “takes every path” too literally. Like, set aside the “infinitely many paths” issue for a moment, and consider just two paths. A quantum superposition of two paths doesn’t mean “it took this path and also it took that path”. A quantum superposition is a different kind of thing from that. A quantum superposition is a linear combination.

A path integral involves an integral of e^{i S/hbar} where S is the action for a given path, with the integral being over the path, and evaluates to the amplitude from the starting state to the ending state.

(Of course, there are some difficulties defining integration over paths, especially if you want to get into QFT. Still.)

If you want to incorporate gravity into this, you probably need to do so within the path integral, with it being incorporated into the action.

But, of course, quantum gravity hasn’t been resolved, so to see why the issue you point to isn’t actually an issue, let me point out that the point you propose applies equally to electromagnetism: say we have an electron, and it goes from one point to another, and nearby we have a positively charged balloon. Replace “mass” with “electric charge” and “gravity” with “electromagnetic force” in your point, and we obtain an argument of the same form. But, QED works extremely well, and doesn’t predict an infinite electric charge in a region when an electron travels from one point to another (for the reason I said: the electromagnetic interaction between the electron and the balloon will appear within the action).

discuss

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squeefers|10 days ago

> Hm, I think you are taking the language “takes every path” too literally.

im taking it as literally as Feynmann took it. people seem to think because their theory is probabilistic, that the world is. theyre mistaken

https://www.youtube.com/watch?v=XcY3ZtgYis0