Professor Fred Walter
Department of Physics and Astronomy
7:30 pm Room 001 ESS Building
Friday, December 16, 2011


In contemporary society, in general one is ashamed to admit to illiteracy. Yet no such stigma is attached to innumeracy, an inability (or refusal) to deal with numbers. Yet the ability to deal with numbers is a crucial skill in a technical age.

This is not a lecture on mathematics, Rather I shall talk about how we deal practically with both very large and very small numbers. How do astronomers determine such quantities as the lifetime of the Sun, number of stars in the Galaxy, or the total mass of the Universe? I shall touch on three topics: estimation, the meaning of the term "exponential growth", and the use and misuse of statistics. Examples will be taken from both astronomy (where the numbers are large) and daily life (where the numbers are more down-to-Earth).

Prof. Walter, a resident of East Setauket, studies star birth, stellar weather, and star death using the CHANDRA and XMM-NEWTON X-ray Observatories, the Hubble Space Telescope, and telescopes in Hawaii and Chile. He has been a professor of Astronomy at Stony Brook since 1989.