The use of CO[subscript 2] laser cutters/engravers in technology and engineering education "allows even beginning students to produce professional parts in a very short time [and] empowers and motivates students, helping to bring out their creativity" (Flowers, 2000, p. 11). They are fast, accurate, fun to use, and they facilitate…

A popular physics legend holds that scissors can cut paper with a speed faster than light. Here this counter-intuitive myth is investigated theoretically using four simple examples of scissors. For simplicity, all cases will involve a static lower scissors blade that remains horizontal just under the paper. In the first case, the upper blade will…

Suppose a red laser beam (of wavelength ? equal to 0.660 µm) is expanded using an optical telescope into a collimated, approximately plane wave that is 5.68 mm in diameter. Pass that beam through a tall rectangular slit whose width "a" is gradually reduced from 3.30 to 0.100 mm. Look at its image on a screen located at a distance…