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.
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.