A theoretical astrophysicist from the University of Kansas may have solved a nearly two-decade-old mystery over the origins ...

A ray diagram showing refraction at the boundary between air and glass Refraction can cause optical illusions as the light waves appear to come from a different position to their actual source.

Sound waves travel at 1,500 m/s in water. The time between sending and receiving a sonar sound pulse that detects a submarine on the seabed is 0.12 s. Calculate how far below the ship the ...