On this day in physics: 13 February 1912 - Robert Millikan began his famous Millikan Oil Drop experiment. The experiment consisted of dropping small droplets of oil between two plates which generated an electric field. The field was varied until the oil droplets were suspended in midair, this the force of the electric field counteracted that of gravity. It was then possible to calculate the charge of an electron knowing the voltage between the plates and the size/weight of the oil droplets. Millikan was able to calculate the charge of an electron to within 1% of our current value, 1.602e-19 C.[Source]
Word of the day- Wave- A wave is an oscillation which transmits energy, but very infrequently mass. The idea is to distinguish a wave from a traveling object. Waves can propagate in several ways. The first is called a longitudinal wave. Think of yourself holding the end of a string with the other end fastened, and shaking it periodically. This is known as a longitudinal wave because the oscillation is perpendicular to the motion of the wave. Another type of wave is a transverse wave, where the oscillation is in the same direction as the motion of the spring. Think of a spring, or slinky, hanging from the ceiling and being pulled straight down, the motion of the wave would be up and down, as would the motion of the wave. Both the example with the string and the spring are what are referred to as mechanical waves, because they involve physical systems through which the wave propagates. There is still another type of wave, the electromagnetic wave, which does not rely on the motion of matter, rather, the wave propagates through a "field", which affects matter in the vicinity of the field, but does not involve matter itself.
Quote of the Day: "If you want to understand the secrets of the universe, think in terms of energy, frequency, and vibration." -Nikola Tesla
Keywords: Wave, Physics, Millikan, Oil, Electron
