>>12391029Space and time are quantized. At a given point in time, there is no motion, because motion is an event, and an event is simply something that changes from one point in time to the next. From one point in time to the very next point in time, any given quantum particle either does not move, or moves to an adjacent point in space. Therefore, from any point in time to the very next point in time, any given quantum particle has a velocity of either 0 or c.
When we observe a quantum particle, we could in theory with precise enough instruments measure its position at any point in time, but the concept of velocity is meaningless at a single point in time since, like I said, motion (velocity) is a process/event, and only has meaning when considered over a timespan (that is, over a period of time including at least two points, rather than a single point aka an instant).
So if we have a "moving" particle (I put "moving" in quotes because again, the concept of "moving" is moot at a single point in time, but now we're considering a longer timespan), we can either measure the exact position at a single point in time where we cannot measure velocity because the concept of velocity doesn't exist if given only a single point in time, or we can measure the average velocity over a timespan consisting of at least two points in time, in which case it is not at the same point during that entire duration, so we can't say "it is at point x while having velocity y" because really it would be more accurate to say "it went from point x to point z over timespan v, therefore having an average velocity of y during timespan v"
