Founded 1871

Fall 2015 & Spring 2016 Lecture Series

Sponsored by The Policy Studies Organization
In Cooperation with the American Public University
The Policy studies OrganizationAmerican Public University

PSW 2358
Friday, February 19th at 8:00 p.m.

Chance vs. Necessity in Mineral Evolution

Robert Hazen
Staff Scientist, Carnegie Institution for Science, and
Clarence Robinson Professor of Earth Sciences, George Mason University


Improving the Tick-Tock

Recent research exploits large databases of mineral types and localities coupled with statistical methods employed by ecologists to document diversity-distribution relations for minerals.  Surprising conclusions are emerging from these new investigations of "mineral ecology":  more than half of Earth's ~5000 mineral species are rare; their distribution conforms to a "Large Number of Rare Events" (LNRE) model that mimics the distribution of words in a book.



The Lectures, which are the centerpiece of all Philosophical Society of Washington meetings, are selected to appeal to those with a general interest in science and do not require a specialized knowledge of the subject. They always contain information that is current, explanations that are understandable and a few controversial issues to be challenged by a critical listener. The series is designed as much as possible to include a wide range of disciplines.

The meetings are open to the public, free, and no reservations are required. Dress is informal. Meetings are followed by lively conversation. All must exit the Cosmos Club at 10:30 p.m. Conversations are continued at another location.

Meeting Location

The John Wesley Powell Auditorium is adjacent to the Cosmos Club, 2170 Florida Avenue NW, Washington DC 20008. Entrance is through the club gate, the first right-hand entrance on Florida Avenue north of the intersection with Massachusetts Avenue NW. The auditorium entrance is to the left of the gate.

The Cosmos Club is within walking distance of the DuPont Circle Metro stop (Q Street exit), the Connecticut Avenue bus routes (L2, L4), and the Massachusetts Avenue bus routes (N2, N4).


Title Name
President Larry S. Millstein
Treasurer John Ingersoll
Program Chair Larry S. Millstein
Membership Chair James Garay Heelan
Corresponding Secretary Robin Taylor