Tell Me Why...?

Many imponderables readers want to know the answer to this question. Perhaps the most complete explanation came from George B Kauffman. Sound is the sensation produced by stimulation of the organs of hearing by vibrations transmitted through the air or other mediums. Low-frequency sound is heard as low pitch and higher frequencies as correspondingly higher pitch. The frequency (pitch) of sound depends on the density of the medium through which the vibrations are transmitted; the less dense the medium, the greater the rate (frequency) of vibration, and hence the higher the pitch of the sound. The densities of gases are directly proportional to their molecular weights. Because the density of helium (mol. wt. 4) is much less than that of air, a mixture of about 78 percent nitrogen (mol. wt. 28) and about 20 percent oxygen (mol. wt. 32). The vocal cords vibrate much faster (at a higher frequency) in helium than in air, and therefore the voice is perceived as havi...

Dimples are a generic name for indentations of the skin. They are produced when muscle fibres are attached to the deep surface of the skin, such as in the cheek or chin , or where the skin is attached to bones by fibrous bands, such as the elbow, shoulder and back. Dimples are most likely to appear where the skin is most tightly attached to the underlying bone . Dr William Jollie, Professor and Chairman of Anatomy at the Medical College of Virginia, says ' dimples probably are due to some developmental fault in the connective tissue that binds skin to bone '. So those dimples we've long envied are actually an anatomical flaw! And the tendency towards dimples seems to be hereditary.