Drake Equation

The Drake equation is a probabilistic argument used to estimate the number of active, communicative extraterrestrial civilizations in the Milky Way galaxy. The equation was written in 1961 by Frank Drake, not for purposes of quantifying the number of civilizations, but as a way to stimulate scientific dialogue at the first scientific meeting on the search for extraterrestrial intelligence (SETI). The equation summarizes the main concepts which scientists must contemplate when considering the question of other radio-communicative life. It is more properly thought of as an approximation than as a serious attempt to determine a precise number.

Criticism related to the Drake equation focuses not on the equation itself, but on the fact that the estimated values for several of its factors are highly conjectural, the combined multiplicative effect being that the uncertainty associated with any derived value is so large that the equation cannot be used to draw firm conclusions.

In 1960, Frank Drake conducted the first search for radio signals from extraterrestrial civilizations at the National Radio Astronomy Observatory in Green Bank, West Virginia. Soon thereafter, the National Academy of Sciences asked Drake to convene a meeting on detecting extraterrestrial intelligence. The meeting was held at the Green Bank facility in 1961. The equation that bears Drake's name arose out of his preparations for the meeting.

This meeting established SETI as a scientific discipline. The meeting's dozen participants - astronomers, physicists, biologists, social scientists, and industry leaders - became known as the "Order of the Dolphin". The Green Bank meeting has been commemorated by a plaque at the site.

The Drake equation is closely related to the Fermi Paradox in that Drake suggested that a large number of extraterrestrial civilizations would form, but that the lack of evidence of such civilizations (the Fermi paradox) suggests that technological civilizations tend to disappear rather quickly. This theory often stimulates an interest in identifying and publicizing ways in which humanity could destroy itself, and then counters with hopes of avoiding such destruction and eventually becoming a space-faring species.

A similar argument is the Great Filter, which notes that since there are no observed extraterrestrial civilizations, despite the vast number of stars, then some step in the process must be acting as a filter to reduce the final value. According to this view, either it is very hard for intelligent life to arise, or the lifetime of such civilizations must be relatively short.

A final argument is the Zoo Hypothesis, which states that super-intelligent extraterrestrial life exists and does not contact life on Earth to allow for its natural evolution and development.

Carl Sagan, a great proponent of SETI, quoted the formula often and as a result the formula is sometimes mislabeled as "The Sagan Equation." Read more ...

Famous Alien-Hunting Drake Equation Inspires New Way to Predict COVID-19 Spread   Science Alert - October 28, 2020
A famous equation used in the search for alien life has inspired a new model that estimates the odds of COVID-19 transmission. The new model - which is essentially a single equation with several terms multiplied together - estimates the risk of COVID-19 transmission through the air. The researchers were motivated in their work by another simple, yet historically significant mathematical formula known as the Drake equation, which estimates the chances of finding intelligent extraterrestrial life in our galaxy.

Developed in 1961 by astronomer Frank Drake, the equation is based on just seven variables and provides an "easy-to-understand framework" for looking at something as seemingly unknowable as the number of alien civilizations, the authors said. They wanted to provide a similar framework for understanding COVID-19 transmission risk.

There's still much confusion about the transmission pathways of COVID-19. This is partly because there is no common 'language' that makes it easy to understand the risk factors involved. The new model, published October 7, 2020breaks down COVID-19 transmission into three stages: the expulsion of virus-containing droplets from an infected person into the air; the dispersion of these droplets; and the inhalation of these droplets by a susceptible person. Overall, the model is composed of 10 variables involved in COVID-19 transmission, including the breathing rate of the infected and susceptible people, the amount of virus particles in the exhaled droplets and the amount of time a susceptible person is exposed, the statement said.