Cameron: I know what he was looking at. (Cameron scans the sky) He was measuring the stars' radial velocity, the distance in parsecs and the Cartesian coordinates.
Eric: What? Why?
Cameron: To pinpoint the date.
Eric: You can tell the date by looking at the sky?
Cameron: Stellar motion can be used to calculate what the sky will look like for hundreds of years in the future, or the past.
Eric: Why is the date so important?
Cameron: It's not … unless it's the wrong date. Myron Stark was in the wrong place at the wrong time.