It is hard to do even sitting on a planet (even impossible) -- there are minute differences in gravity and acceleration between any two points, so time flows with different speeds. And it changes all the time.
If something is possible theoretically, it may not be in practice. But if something is proven to be impossible, it's also impossible in practice.
Note we're not talking about "below a millisecond" or below any other time range (second, minute, month). We're talking about _exactly_.
If something is possible theoretically, it may not be in practice. But if something is proven to be impossible, it's also impossible in practice.
Note we're not talking about "below a millisecond" or below any other time range (second, minute, month). We're talking about _exactly_.