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
Our understanding of the universe has changed over time. Different civilisations have created different models to explain what the universe is and how the universe began. The Greek astronomer Ptolemy (c90-168AD) used measurements of the sky to create his geocentric model. This had the earth at the centre and all the planets and the sun orbiting around it.