... 22a.Starlight Aberration . ... 24a.The Rotating Earth . ... Seen from the boat, the flag always points to the rear, because in the boat's frame of reference, a wind with velocity ?u seems to be blowing. It always points in the same direction. ... The vector PA represents the velocity of light coming from Polaris at c=300,000 km/s. The vector AB represents the velocity ?u of Polaris relative to Earth, equal in size to the Earth's velocity u =30 km/s in its orbit, but in opposite direction. ...