In physics, the critical angle is described with respect to the normal line.

Here, the main part enters the solid body above the critical angle.

As a result there is no critical angle (total reflection) for the interface from air to water.

The critical angle of attack will always stall the aircraft.

Very well, what is meant by the critical angle of incidence?

But at critical angles, the waves are reflected back toward the surface.

There is any easy way to check this critical angle without having to measure distance or lengths.

Above this critical angle of attack, the aircraft is said to be in a stall.

Every material has a critical angle, at which point light is reflected back internally.

The critical angle is approximately 41 for glass in air.