Web edition: August 6, 2001
TWO ARISTOCRATIC LADIES EMERGE FROM RETIREMENT
There is something about newly-emerged silkworm moths that makes one think of the ladies of Cathay or Cipangu, long ago and far away, clothed in silk spun by ancestors of today’s silk worms.
In the cover picture of this week’s Science News Letter, Cornelia Clarke has made an admirable camera capture of that atmosphere, most palpable to the fingers of the eye, but not to be snared in words.
DRYING LAKES AND SOIL EROSION DESTROYED MAYAN EMPIRE
Because the face of the land in which they lived began to change insidiously, fatally, the Mayas of prehistoric America temporarily lost their grip on civilization, and their first empire fell. This, at least, is the view advanced by a geologist who has returned from the region where America’s greatest prehistoric civilization once flourished and then mysteriously succumbed.
The geologist, Dr. C. Wythe Cooke of the U.S. Geological Survey, was sent by the Carnegie Institution of Washington to study the region within traveling range of the institution’s camp at Uaxactun, Guatemala. Reporting his observations in the Journal of the Washington Academy of Sciences, Dr. Cooke describes the hill and lowland country as it is, and as it doubtless appeared in the days when the Mayas had their beautiful cities and their farms there.
The hills today are forested with big trees and a little underbrush. The lowlands are flat plains covered with a tangled mass of gnarled and twisted trees, festooned with vines. In the rainy season these low plains are flooded. At one time evidently the plains were lakes all the year round, affording plenty of water for the region and good transportation. Both water supplies and transportation are highly inadequate today.
Dr. Cooke suggests that quite possibly the transition from lake to lowland took place during the time of the Mayan Empire. If so, this would explain many facts about Mayan economics now hard to understand.
COLOR MUSIC MADE DIRECTLY FROM SOUND OF INSTRUMENTS
Irregular shapes of red, green, blue, and white light flashed and twisted on a screen here in time with orchestral music as Edward B. Patterson, R.C.A. Victor engineer, gave his first public demonstration of a new method of color music.
His apparatus seems to have solved many of the technical problems involved. It is the first in which the color is actually operated by sound. Previous experimental machines have operated the color instruments entirely separately from sound instruments.
One of the most recent members of the ever-increasing family of vacuum tubes—the thyratron—is at the heart of the Patterson apparatus. With this device a very minute change in electrical current is able to control the flow of a much larger power.
The input is in the form of a small electrical current which may come from a microphone picking up the sound waves from an actual musician or orchestra, or it may come direct from the electrical pickup of a phonograph. In the latter case, as demonstrated in Philadelphia, a loudspeaker can also be connected in the circuit, to give the sound along with the color.
The input is passed through a group of four wave filters, each picking out a band of vibrations. One passes only the low notes, another those a little higher, a third those still higher pitched, and a fourth the shrill notes. The currents from these filters are further amplified and then operate the thyratron tubes, which in turn operate colored lamps, one for each band of waves.