© Clive Grainger, 2010.
Can a baseball pitcher suffer from quantum mechanical jitter? According to the uncertainty principle, confining the baseball in the pitcher's hand inevitably causes it to jitter. However, as the calculation shows, even if the ball is confined as tightly as the thickness of a hair, the time to see the effect of the jitter would be more than the age of the universe. Although baseball pitchers do not need to worry about quantum mechanical jitter, this zero-point motion can be significant in nano-mechanical devices. For instance, zero-point motion in the electromagnetic field, otherwise called "vacuum fluctuation," gives rise to attractive forces between bodies, called "Casimir forces," that can limit mechanical sensitivity. (Unit: 5)