NOTES:
Here's a demonstration of the difficulty in taking off from Ringworld. At 8 miles/second a rocket would leave earth easily, but on Ringworld at the same velocity a projectile crashes badly and is moved to the left of the takeoff point (assuming that the ring is rotating rightward). Aiming slightly left or right causes no real change except that the same angle of launch results in slightly different maximum altitudes and displacements on the ground (aiming against the spin improves the height by about 36 miles over aiming with the spin - not very useful).