- In September 1959, physicists Giuseppe Cocconi and Philip Morrison published an article in the journal Nature with the provocative title "Searching for Interstellar Communications."[2][3] Cocconi and Morrison argued that radio telescopes had become sensitive enough to pick up transmissions that might be broadcast into space by civilizations orbiting other stars. Such messages, they suggested, might be transmitted at a wavelength of 21 centimeters (1,420.4 megahertz). This is the wavelength of radio emission by neutral hydrogen, the most common element in the universe, and they reasoned that other intelligences might see this as a logical landmark in the radio spectrum.
Dr. Frank Drake Seven months later, radio astronomer Frank Drake became the first person to start a systematic search for intelligent signals from the cosmos. Using the 25 meter dish of the National Radio Astronomy Observatory in Green Bank, West Virginia, Drake listened in on two nearby Sun-like stars: Epsilon Eridani and Tau Ceti. In this project, which he called Project Ozma, he slowly scanned frequencies close to the 21 cm wavelength for six hours per day from April to July 1960.[3] The project was well designed, cheap, simple by today's standards, and unsuccessful.
Soon thereafter, Drake hosted a "search for extraterrestrial intelligence" meeting on detecting their radio signals. 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.[4]
As I planned the meeting, I realized a few day[s] ahead of time we needed an agenda. And so I wrote down all the things you needed to know to predict how hard it's going to be to detect extraterrestrial life. And looking at them it became pretty evident that if you multiplied all these together, you got a number, N, which is the number of detectable civilizations in our galaxy. This was aimed at the radio search, and not to search for primordial or primitive life forms. —Frank Drake.
The ten attendees were conference organiser Peter Pearman, Frank Drake, Philip Morrison, businessman and radio amateur Dana Atchley, chemist Melvin Calvin, astronomer Su-Shu Huang, neuroscientist John C. Lilly, inventor Barney Oliver, astronomer Carl Sagan and radio-astronomer Otto Struve.[5] These participants dubbed themselves "The Order of the Dolphin" (because of Lilly's work on dolphin communication), and commemorated their first meeting with a plaque at the observatory hall.[6][7]
From the Drake Equation Wikipedia Page
I do like the equation, but BECAUSE it is mostly a guess and not so rigorous. The drake equation is not a mathematical proof, neither is it a physical law. It is essentially, a guess. Maybe that makes you uncomfortable because the guess is in the realm of science. But most of science is just guessing, some educated, and some not. Scientists and researchers don't like to admit they are guessing, for the most part anyway, because they have this veil of accuracy. "Look my algorithm found the correct answer 95% of the time" "Look we made a thing that does a thing for that thing very often" But remember what the second part of the scientific method is: Hypothesis. Now a hypothesis is not always a guess, in the traditional sense of the word. But it's an important part of science. We observe: A nail is sticking out of a board Guess: A hurricane swept through the neighborhood, carrying the nail on the edge of its storm, which eventually found the board and thrust inside of it, and dropped it for me to find. I know this because there was a hurricane in florida and hurricanes are powerful. Hypothesis: The nail was likely placed with a hammer. I can see marks on the nail the hammer left, I can see imprints of the hammer on the edge of the head. It is likely a type of refuse that was left here on accident. In this sense, Drake is simply saying, "Here is what we know about life so far, given our sample of 1 we can eliminate these factors, leaving us with a map of likely candidates" It is neither accurate, nor precise at the current time. But if a guess is all you have, a guess is all you have. There is a famous quotation by Newton, although it may have never been said by him: "No great discovery was ever made without a bold guess"
I am no mathematician but this certainly seems like somewhat of a wild guess but it is also a great conversation starter. It gets me to think about factors that otherwise, I would not have.