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
Eratosthenes was a Greek expert in many disciplines, including astronomy, geography, and mathematics. He is most famous for his calculation of Earth's circumference and for inventing the word geography. Born in Cyrene, in what is now Libya, in 276 B.C., Eratosthenes grew up curious and went to Athens to learn more about the world around him. He studied at Plato's Academy and learned Stoicism from its founder, Zeno.