N2NH
08-08-2011, 01:20 PM
Yes, we have a good idea. In fact we have scientifically known for around a half century. It's the SCIENTIFIC formula known as the Drake Formula. It helped to get Star Trek on Television, well, sorta. It's also the way SETI operates and why they listen the way they do.
The Drake equation states that:http://upload.wikimedia.org/math/4/a/c/4ac1a1c3e0f903e8ed70359a4bb99466.pngwhere:
N = the number of civilizations (http://en.wikipedia.org/wiki/Civilization) in our galaxy with which communication might be possible;and
R* = the average rate of star (http://en.wikipedia.org/wiki/Star) formation per year in our galaxy
(http://en.wikipedia.org/wiki/Milky_Way)fp = the fraction of those stars that have planets
(http://en.wikipedia.org/wiki/Planet)ne = the average number of planets that can potentially support life (http://en.wikipedia.org/wiki/Life) per star that has planets
fℓ = the fraction of the above that actually go on to develop life at some point
fi = the fraction of the above that actually go on to develop intelligent (http://en.wikipedia.org/wiki/Intelligence) life
fc = the fraction of civilizations that develop a technology that releases detectable signs of their existence into space
L = the length of time for which such civilizations release detectable signals into space.[3 (http://en.wikipedia.org/wiki/The_Drake_Equation#cite_note-2)] (http://en.wikipedia.org/wiki/The_Drake_Equation#cite_note-3)
It has alternatively been expressed as:
The number of stars in the galaxy now, N*, is related to the star formation rate R* byhttp://upload.wikimedia.org/math/9/1/0/910753167fad20256dacdd8983101e7d.pngwhere Tg = the age of the galaxy.
Assuming for simplicity that R* is constant, then
http://upload.wikimedia.org/math/e/5/9/e59241ca83723b5b603e2d22b39c6ad8.png and the Drake equation can be rewritten into an alternate form phrased in terms of the more easily observable value, N*.[4]
(http://en.wikipedia.org/wiki/The_Drake_Equation#cite_note-3)
http://upload.wikimedia.org/math/8/4/6/846953db691bd7f2123caa767626d2af.png
Regarding SETI (and in the past Carl Sagan):
In 1960, Frank Drake conducted the first search for radio signals from extraterrestrial civilizations at the National Radio Astronomy Observatory in Green Bank (http://en.wikipedia.org/wiki/Green_Bank,_West_Virginia), West Virginia (http://en.wikipedia.org/wiki/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:
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, of course, was aimed at the radio search, and not to search for primordial or primitive life forms.
— Frank Drake[1] (http://en.wikipedia.org/wiki/The_Drake_Equation#cite_note-0)
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 (http://www.setileague.org/photos/miscpix/drakeqn.jpg) at the site.
As far as Star Trek...
The equation was cited by Gene Roddenberry (http://en.wikipedia.org/wiki/Gene_Roddenberry) as supporting the multiplicity of inhabited planets shown in Star Trek (http://en.wikipedia.org/wiki/Star_Trek), the television show he created. However, Roddenberry didn't have the equation with him, and he was forced to "invent" it for his original proposal.[31] (http://en.wikipedia.org/wiki/The_Drake_Equation#cite_note-30) The invented equation created by Roddenberry is:
http://upload.wikimedia.org/math/1/6/3/163f4b0e90c76794df4097dbc199fc47.png
Drake has gently pointed out, however, that a number raised to the first power is merely the number itself. A poster with both versions of the equation was seen in the Star Trek: Voyager (http://en.wikipedia.org/wiki/Star_Trek:_Voyager) episode "Future's End (http://en.wikipedia.org/wiki/Future's_End)."
One equation, drawn up for one meeting in 1960 and it has changed our world and our view of the universe. In both mass media and scientifically. Well, IMHO, of course. I'm sure some will say this is unscientific, but there you go. :lol:
The Drake Equation. (http://en.wikipedia.org/wiki/The_Drake_Equation)
The Drake equation states that:http://upload.wikimedia.org/math/4/a/c/4ac1a1c3e0f903e8ed70359a4bb99466.pngwhere:
N = the number of civilizations (http://en.wikipedia.org/wiki/Civilization) in our galaxy with which communication might be possible;and
R* = the average rate of star (http://en.wikipedia.org/wiki/Star) formation per year in our galaxy
(http://en.wikipedia.org/wiki/Milky_Way)fp = the fraction of those stars that have planets
(http://en.wikipedia.org/wiki/Planet)ne = the average number of planets that can potentially support life (http://en.wikipedia.org/wiki/Life) per star that has planets
fℓ = the fraction of the above that actually go on to develop life at some point
fi = the fraction of the above that actually go on to develop intelligent (http://en.wikipedia.org/wiki/Intelligence) life
fc = the fraction of civilizations that develop a technology that releases detectable signs of their existence into space
L = the length of time for which such civilizations release detectable signals into space.[3 (http://en.wikipedia.org/wiki/The_Drake_Equation#cite_note-2)] (http://en.wikipedia.org/wiki/The_Drake_Equation#cite_note-3)
It has alternatively been expressed as:
The number of stars in the galaxy now, N*, is related to the star formation rate R* byhttp://upload.wikimedia.org/math/9/1/0/910753167fad20256dacdd8983101e7d.pngwhere Tg = the age of the galaxy.
Assuming for simplicity that R* is constant, then
http://upload.wikimedia.org/math/e/5/9/e59241ca83723b5b603e2d22b39c6ad8.png and the Drake equation can be rewritten into an alternate form phrased in terms of the more easily observable value, N*.[4]
(http://en.wikipedia.org/wiki/The_Drake_Equation#cite_note-3)
http://upload.wikimedia.org/math/8/4/6/846953db691bd7f2123caa767626d2af.png
Regarding SETI (and in the past Carl Sagan):
In 1960, Frank Drake conducted the first search for radio signals from extraterrestrial civilizations at the National Radio Astronomy Observatory in Green Bank (http://en.wikipedia.org/wiki/Green_Bank,_West_Virginia), West Virginia (http://en.wikipedia.org/wiki/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:
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, of course, was aimed at the radio search, and not to search for primordial or primitive life forms.
— Frank Drake[1] (http://en.wikipedia.org/wiki/The_Drake_Equation#cite_note-0)
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 (http://www.setileague.org/photos/miscpix/drakeqn.jpg) at the site.
As far as Star Trek...
The equation was cited by Gene Roddenberry (http://en.wikipedia.org/wiki/Gene_Roddenberry) as supporting the multiplicity of inhabited planets shown in Star Trek (http://en.wikipedia.org/wiki/Star_Trek), the television show he created. However, Roddenberry didn't have the equation with him, and he was forced to "invent" it for his original proposal.[31] (http://en.wikipedia.org/wiki/The_Drake_Equation#cite_note-30) The invented equation created by Roddenberry is:
http://upload.wikimedia.org/math/1/6/3/163f4b0e90c76794df4097dbc199fc47.png
Drake has gently pointed out, however, that a number raised to the first power is merely the number itself. A poster with both versions of the equation was seen in the Star Trek: Voyager (http://en.wikipedia.org/wiki/Star_Trek:_Voyager) episode "Future's End (http://en.wikipedia.org/wiki/Future's_End)."
One equation, drawn up for one meeting in 1960 and it has changed our world and our view of the universe. In both mass media and scientifically. Well, IMHO, of course. I'm sure some will say this is unscientific, but there you go. :lol:
The Drake Equation. (http://en.wikipedia.org/wiki/The_Drake_Equation)