The Drake equation in the search for answers I
4th Day of Lockdown
In 1961 Frank Drake made one of the first searches for signals from extraterrestrial civilizations. He used the 25 m dish of the National Radio Astronomy Observatory, in Green Bank, West Virginia, and closely monitored two stars, for six hours per day. The project was well prepared, and simple by today's standards. It detected no signals.
Soon after, Drake hosted a "search for extraterrestrial intelligence" meeting. Drake came up with the equation that bears his name to provide a way to estimate the number of active, communicative extraterrestrial civilizations in the Milky Way galaxy and thus better formulate the meeting's agenda.
Among the meeting's ten attendees was Carl Sagan, who later in his famous book COSMOS, devotes a special chapter to the topic.
The Drake equation is:
N = N𝐨 * f𝑝 * n𝑒 * f𝑙 * f𝑖 * f𝑐 * f𝐿
where:
N = the number of civilizations in our galaxy with which communication might be possible (i.e. which are on our current past light cone);
and
N𝐨 = the number of stars in the Milky Way Galaxy
fp = the fraction of those stars that have planetery systems
ne = the average number of planets in a given system that can potentially support life
fl = the fraction of otherwise suitable planets that actually develop life at some point
fi = the fraction of planets with life that actually go on to develop intelligent life (civilizations)
fc = the fraction of civilizations that develop a technology that releases detectable signs of their existence into space
f𝐋 = the fraction of planetary time for which such civilizations release detectable signals into space
All the f 's are fractions with values between 0 and 1, they lower the large value of N.
The Drake equation is not a formula for a law of nature. It provides a way to make reasonable guesses to the solution of a problem involving subjects ranging from stellar and planetary astronomy to organical chemistry, evolutionary biology, history, politics and abnormal psychology.
To calculate N one must estimate each of these quantities. Scientists have a good knowledge for the first factors of the equation. But we do not know much about the later factors. Different estimates can vastly vary the result.
The range of answers to the equation is a measure of our ignorance and different results act as ways to guide our thoughts and stimulate dialogue on these topics.
I wanted to draw attention to this equation and make use of its simplicity in order to formulate the problems we are facing today, where many different parameters affect the outcome of the questions we urgently need an answer to.
That is all for today,
Stay safe, be healthy!
Drake equation, https://en.wikipedia.org/wiki/Drake_equation#Equation , Wikipedia.org
Carl Sagan, Cosmos, The story of cosmic evolution, science and civilisation, London, Abacus, 1995.
In 1961 Frank Drake made one of the first searches for signals from extraterrestrial civilizations. He used the 25 m dish of the National Radio Astronomy Observatory, in Green Bank, West Virginia, and closely monitored two stars, for six hours per day. The project was well prepared, and simple by today's standards. It detected no signals.
Soon after, Drake hosted a "search for extraterrestrial intelligence" meeting. Drake came up with the equation that bears his name to provide a way to estimate the number of active, communicative extraterrestrial civilizations in the Milky Way galaxy and thus better formulate the meeting's agenda.
Among the meeting's ten attendees was Carl Sagan, who later in his famous book COSMOS, devotes a special chapter to the topic.
The Drake equation is:
N = N𝐨 * f𝑝 * n𝑒 * f𝑙 * f𝑖 * f𝑐 * f𝐿
where:
N = the number of civilizations in our galaxy with which communication might be possible (i.e. which are on our current past light cone);
and
N𝐨 = the number of stars in the Milky Way Galaxy
fp = the fraction of those stars that have planetery systems
ne = the average number of planets in a given system that can potentially support life
fl = the fraction of otherwise suitable planets that actually develop life at some point
fi = the fraction of planets with life that actually go on to develop intelligent life (civilizations)
fc = the fraction of civilizations that develop a technology that releases detectable signs of their existence into space
f𝐋 = the fraction of planetary time for which such civilizations release detectable signals into space
All the f 's are fractions with values between 0 and 1, they lower the large value of N.
The Drake equation is not a formula for a law of nature. It provides a way to make reasonable guesses to the solution of a problem involving subjects ranging from stellar and planetary astronomy to organical chemistry, evolutionary biology, history, politics and abnormal psychology.
To calculate N one must estimate each of these quantities. Scientists have a good knowledge for the first factors of the equation. But we do not know much about the later factors. Different estimates can vastly vary the result.
The range of answers to the equation is a measure of our ignorance and different results act as ways to guide our thoughts and stimulate dialogue on these topics.
I wanted to draw attention to this equation and make use of its simplicity in order to formulate the problems we are facing today, where many different parameters affect the outcome of the questions we urgently need an answer to.
That is all for today,
Stay safe, be healthy!
Drake equation, https://en.wikipedia.org/wiki/Drake_equation#Equation , Wikipedia.org
Carl Sagan, Cosmos, The story of cosmic evolution, science and civilisation, London, Abacus, 1995.
Very interesting, indeed! Will you be exploring possible adaptations of the formula to fit our current situation in subsequent posts?
ReplyDeleteThanks nchlo, that's the idea.
ReplyDelete