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Factors Affecting Calculation of L


Mark P. A. Ciotola




A detectable extraterrestrial civilization can be modeled as a series of successive regimes over time each of which is detectable for a certain proportion of its lifecycle.  This methodology can be utilized to produce an estimate for L.

Potential components of L include quantity of fossil fuel reserves, solar energy potential, quantity of regimes over time, lifecycle patterns of regimes, proportion of lifecycle regime is actually detectable, and downtime between regimes.   Relationships between these components provide a means of calculating the lifetime of communicative species in a detectable state, L.

An example of how these factors interact is provided, utilizing values that are reasonable given known astronomical data for components such as solar energy potential while existing knowledge about the terrestrial case is used as a baseline for other components including fossil fuel reserves, quantity of regimes over time, and lifecycle patterns of regimes, proportion of lifecycle regime is actually detectable, and gaps of time between regimes due to recovery from catastrophic war or resource exhaustion.

A range of values is calculated for L when parameters are established for each component so as to determine the lowest and highest values of L.



L, lifetime, communicative species, regimes, lifecycle, detectability.


  • The paper (author Web site)


Author Biography

B.A. in Economics, University of Wisconsin- Madison, 1985. J.D., Franklin Pierce Law Center, 1988.  Employed by San Jose State University Foundation and San Francisco State University to assist with technology commercialization at NASA Ames Research Center and its affiliates, 1988-1995.  Presently pursuing coursework in physics and astronomy at San Francisco State University.


Author Affiliation

Dept. of Physics and Astronomy San Francisco State University
1600 Holloway Ave. TH 334
San Francisco , CA 94132
Phone: 415-564-4114
Fax: 415-338-2178
Email: mciotola@stars.sfsu.edu


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