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by bill_from_tampa 2258 days ago
> If numbers are finite and limited in their precision, then nature itself is inherently imprecise, and thus unpredictable.

Is this not what Planck's constant implies? We can only know position and/or motion to a certain degree, and not exactly? Does not quantum mechanics already include this idea?

2 comments

How does discreetness imply imprecision and randomness? If anything, it should indicate some degree of certainty.
I'm an amateur, but I like to think about this:

If spacetime is quantized, then the speed of light would be 1 planck length / 1 planck time. Assuming spacetime is actually quantized to that metric, we can then ask: How does something move at 2/3c? Or two discrete planck lenghts in 3 discrete planck times?

In one instance it could be:

t=0,x=0, t=1,x=0, t=2,x=1, t=3,x=2

It could also do:

t=0,x=0, t=1,x=1, t=2,x=1, t=3,x=2.

It implies a hidden variable, or at the very least a hidden phase of some sort. All sorts of oddness abounds when you consider all velocities are then quantized fractional values of c.

If you can have real numbers at each spacetime point (as opposed to boolean values) then you can easily get a speed less than c. This is similar to simulating the wave equation on a grid on a computer.
But then your 2/3c is an average, it's not the real speed of the object at any actual instant.
It depends on your rules for rounding I think.
You're thinking of the Heisenberg Uncertainty Principle