I am a layman. I am aware that the Alcubierre Drive has not yet been proven to be possible, but there is something about the concept itself that I am confused about. If there is no movement within the bubble, how is time measured inside the bubble? If there is no velocity, what is time measured against?
The passage of time inside the bubble will be the same as outside the bubble; the passengers inside the bubble will be able to transfer between points separated by vast distances as if they were effectively moving faster than the speed of light but locally this is not the case since it is impossible to move faster than the speed of light locally. The bubble itself will have regions of incredible tidal forces and time dilation however the positive and negative curvatures will in a way cancel out around at the bubbles surface making this possible.