4 November 2007

If a tree falls in the forest and no one is there to hear it it does not make a sound.

Sound 1 The sensation of hearing; that which is heard; specif.: a Psychophysics. Sensation due to stimulation of the auditory nerves and auditory centers of the brain, usually by vibration transmitted in a material medium, commonly air, affecting the organ of hearing. b Physics. Vibrational energy which occasions such sensations. Sound is propagated bu progressive longitudinal vibratory disturbances (sound waves). 2 A tone or noise of a special quality or character; as, a soundof rejoicing. 3 Import or implications of something heard, read, etc.; as, I don’t like the soundof this letter. 4 Archaic. rumor; fame. 5 Noise without meaning; mere noise. 6 Hearing distance; earshot.

So there is no sound unless there is an animate being there to perceive the vibrations. Therefore if a tree falls in the forest and no one hears it, it did not make a sound.

Following that logic there should not be any waves on the ocean if there is no one there to see them.

Wave --n. 7. Physics. A single pulse in a vibrational disturbance advanced through a body or elastic medium (gas or a liquid), as in the transmission of light, sound, etc.; the disturbance included in a space of one wave length. If the disturbance producing the wave is periodic, so will be the waves. The simple periodic wave results when each particle, or elementary portion, of the medium undergoes simple periodic changes through each complete revolution, or through an angle of 360°; the phase of vibration varies continuously from particle to particle in the direction of the advance of the wave.

And if it applies to sound it should also apply to light since it is also a wave.

Light --n 1. The essential condition of vision; the opposite of darkness; hence: a an emanation from a light-giving body; as , flames giving light. b The sensation aroused by stimulation of the visual centers in the brain. 2. The sun’s light; daylight; also, day; esp. the dawn of day. . . . 15. Physics. a The radiant energy which, by its action upon the organs of vision enables them to perform their function of sight – more accurately called luminous energy. Light is transmitted by an undulatory, or vibrational movement at a velocity of about 186,3000 miles a second. b Radiant energy incapable of appreciably affecting the average normal retina (ultraviolet light or infrared light), but otherwise like luminous energy. c The rate of trnasters of luminous energy. Its unit is the lumen.

So we come full circle. The answer to Peter’s question, “Do all colors exist in Nature?”, appears to be that only those colors exist which are being perceived by someone at any instant in time. But since white light is the sum of all other possible colors, all colors do exist whenever white light is perceived.

All definitions from Webster's Collegiate Dictionary, Fifth Edition, © 1941.