Education » The Science of Khet
FOLLOW THE BOUNCING BEAM
Don't be intimidated by Khet's high tech looks; the basic principles behind the game can be understood easily! When a laser beam hits a mirrored surface, it will always bounce at a 90 degree angle. In other words, it will never bounce off at some weird angle into another row, but will always take a right or left turn, depending on which way the mirror is facing, and stay in a straight line until it hits another object as shown in the following picture:
HOW IT WORKS
Just like in pool or billiards, light bounces off at the same angle it hits a mirrored surface. If light hits a surface at a 45 degree angle, it will bounce off at a 45 degree angle. In science terms, the angle of reflection is equal to the angle of incidence.
Khet takes advantage of this principal by positioning all its mirrored surfaces at 45 degree angles relative to the board. Since the light hits at a 45 degree angle, it will then bounce off at a 45 degree angle making the total angle of reflection 90 degrees, or one quarter turn. Now, whenever the beam hits a mirrored surface at any point on the board it will always take a quarter turn in the direction the mirror was aimed and continue on a straight path in the row it was reflected as shown above.
THE SCIENCE OF BEAM SPLITTING
Several ways exist to split light into multiple directions. The Khet "Eye of Horus Beam splitters" use a plastic sheet with a semi-transparent mirrored coating. This coating reflects a portion of the light energy and transmits most of the remaining energy. Beam splitters are used in everyday optical devices such as cameras and CD players. In science experiments, beam splitters are used in laser holography and in several fascinating measurement techniques. For more information check out one of the references at your local library or online.
