The Status of Silk

By 3000 B.C. the Chinese had discovered that the filament covering a silk worm cocoon could be unwound and woven into fabric. China guarded the secret of sericulture until about A.D. 300. By then , through Korean weavers migrating from China, Japan had learned the technique and soon mastered weaving and dyeing . Traders had also carried silk into Europe along the 4,000 mile Silk Road; Roman law for bade men from wearing the fabric, perceived as too feminine. Two Persian monks smuggled silkworms to Constantinople in the sixth century, and the art of silk production came to Europe. It flourished there until World War II, after which China and Japan regained their domination of silk production. Silk remains a mark of luxury and status.

Single Mulberry Silkworm

A SINGLE MULBERRY SILKWORM grows to a length of less than three inches, but it can weave a cocoon whose silken thread, when unwound, measures more than a mile.

What are Hadley Cells?

FUN FACT:
In the desert area of Cochones, Chile, it did not rain from 1919 to 1965.

The lack of desert rain results partly from a pattern of air circulation described by George Hadley in 1735. In an effort to explain the direction of the trade winds, Hadley conjectured that air around the Equator will constantly rise and move toward the Poles as it warms, and then it will move back toward the Equator as it cools and falls, creating areas, cells , where air temperature and pressure are quite constant.

Hadley’s theory does not work on a global scale, but Hadley cells do help explain atmospheric patterns around the Equator. Many of the world’s deserts lie at the outer edge of these cells, beneath areas of dry air that have disgorged their moisture over tropical and subtropical forests.

The Polar Bear : Victim of Global Warming

In May 2008, the United States added the polar bear to the list of threatened species protected under the U.S. Endangered Species Act. Activists had supported the listing for a number of years, recognizing that the polar ice cap was melting at even a greater rate than predicted with new estimates that it might melt completely by 2099. Polar bears rely on the ice cap to stage their hunting of ringed seals and other prey, so the loss of the ice poses a distinct threat to their survival. While a robust male polar bear can measure 11 feet tall and weigh up to 1,200 pounds, there is evidence that the species is losing its vigor and suffering a decline in size. There has also been a noticeable decline in the survival rate of cubs, which usually are born as twins in the winter.

Polar Bear

A POLAR BEAR LEAPS across gaps in the pack ice in Norway’s Northeast Svalbard Nature Preserve. As polar ice floes melt and shrink, polar bears are losing precious habitat. In 2008 the U.S. declared polar bears a threatened species, citing sea ice loss due to global warming as the cause.

Lil Scientist