Describes how COPD, or chronic obstructive pulmonary disease, is a progressive disease that makes it hard to breathe. Details the symptoms of COPD. Shows how the disease works in the lungs. Explains how progress of the disease can be slowed.
Eratosthenes of Cyrene was a Greek mathematician, geographer, poet, astronomer, and music theorist. He was a man of learning, becoming the chief librarian at the Library of Alexandria. He invented the discipline of geography, including the terminology used today. He is best known for being the first person to calculate the circumference of the Earth, which he did by comparing altitudes of the mid-day sun at two places a known North-South distance apart. His calculation was remarkably accurate. H
Later scientists called Aristotle the Father of Natural Science because centuries after the ancient scholar's death, his methods formed the basis of the scientific method. Most people in Aristotleâs time believed the earth was flat, but he did not agree. The Greek thinker realized that a lunar eclipse occurred when the earth came between the sun and the moon. The shape of the earthâs shadow, Aristotle observed, was round. If the earth were flat, its shadow would have a much different form. Next, Aristotle considered the position of the North Star. The farther north you journeyed, the closer the North Star seemed to move to the middle of the sky.