Natural Forces A natural force is a power brought on by nature. , unlike those of other powers, are uncontrollable. When a hurricane passes along the coast, a bolt of lightning strikes a rooftop, and a volcano erupts, these are all examples of natural forces. can have devastating effects on wildlife, humans, and the earth itself. Our effe...
Sputnik, name of the first of several artificial satellites launched by the Soviet Union from 1957 to 1961. The goals of the Sputnik program included studying the earth?s upper atmosphere, observing animal survival in space flight, and testing Soviet rocket technology. The launch of the unmanned Sputnik 1 and of Sputnik 2, which ca...
Acupuncture is a Chinese medical practice that treats illness and provides local anesthesia by the insertion of needles at predetermined sites of the body. Acupuncture may also follow many other forms. The word acupuncture comes from the Latin word acus, meaning needle, and pungere, meaning puncture. The Chinese call acupuncture Ch...
AIDS Acquired immune deficiency syndrome, or AIDS, is a recently recognized disease. It is caused by infection with the human immunodeficiency virus (HIV). AIDS is a complicated illness that may involve several phases. It is caused by a virus that can be passed from person to person. AIDS impairs the human body's immune s...
Chemical reactions are the heart of chemistry. People have always known that they exist. The Ancient Greeks were the firsts to speculate on the composition of matter. They thought that it was possible that individual particles made up matter. Later, in the Seventeenth Century, a German chemist named George Ernst Stahl was the first to...