APL Colloquium

January 9, 2009

Colloquium Topic: “Guesstimation:” Fermi Problems, Orders of Magnitude, and the Goldilocks Principle

The ability to estimate is an important skill in daily life. Guesstimation, used by generations of engineers and scientists, is a straightforward arithmetic process that unlocks the power of approximation--answers rounded to the nearest power of ten! More and more leading businesses today use estimation questions in interviews to test applicants' abilities to think on their feet. Guesstimation enables anyone with basic math and science skills to estimate virtually anything--quickly--using plausible assumptions and elementary arithmetic. Guesstimation can be applied to an eclectic array of problems that range from devilishly simple to quite sophisticated and from serious real-world concerns to downright silly ones. How long would it take a running faucet to fill the inverted dome of the Capitol? What is the average length of a woman’s hair? How many people in the world are picking their noses at this moment? How much would the ocean surface rise if the ice caps melted? How much land would be required to supply the US energy needs with solar energy? The problems are very diverse, yet the skills to solve them are the same. It is straightforward to derive useful ballpark estimates by breaking complex problems into simpler, more manageable ones—noting that sometimes there can be several paths to the right answer.

Colloquium Speaker: John Adam

John Adam is a University Professor at Old Dominion University in the Department of Mathematics and Statistics. He holds a BSc in Physics and a PhD in Theoretical Astrophysics both from the University of London. His research has covered a variety of areas: astrophysical fluid dynamics, magnetohydrodynamics, and singular differential equations, but during the last 20 years he has been involved in mathematical biology, and currently working on mathematical models of atmospheric optical phenomena, such as rainbows, halos and glories. He has published 95 papers in scientific and mathematical journals, made numerous professional presentations (both invited and contributed) at universities and research institutions, as well as many community schools and organizations. His book Mathematics in Nature: Modeling Patterns in the Natural World, published by Princeton University Press in 2003 (and in paperback in 2006), was the winner of the American Association of Publishers Award for the most scholarly book in Mathematics and Statistics in 2003, and was selected by Choice Magazine as one of their Outstanding Academic Titles for 2004. He is co-author, with Professor Larry Weinstein, of the book, Guesstimation: Solving the World’s Problems on the Back of a Cocktail Napkin. Another book, A Mathematical Nature Walk, is due to be published by Princeton University Press in early 2009.