As in: Is there life on other planets?
Last Saturday, we went to the local Freethinkers meeting in Grants Pass. It was a fascinating presentation by fellow member, Chas Rogers. Chas teaches Earth Science courses for the Rogue Community College and elsewhere.
Here is a taste of what we saw:
The Rare Earth Hypothesis argues that the development of complex life on Earth, not to mention intelligence, was an incredibly improbable thing in terms of the geological and astronomical variables involved, suggesting that the galaxy is not filled with other intelligent life forms waiting to be found.
One important factor is the Drake Equation. Here it is explained on the SETI website:
How many alien societies exist, and are detectable? This famous formula gives us an idea. The Drake Equation, which was the agenda for a meeting of experts held in West Virginia in 1961, estimates N, the number of transmitting societies in the Milky Way galaxy.
Here is that Drake Equation.
N : The number of civilizations in the Milky Way galaxy whose electromagnetic emissions are detectable.
R* : The rate of formation of stars suitable for the development of intelligent life (number per year).
fp : The fraction of those stars with planetary systems.
ne : The number of planets, per solar system, with an environment suitable for life.
fl : The fraction of suitable planets on which life actually appears.
fi : The fraction of life bearing planets on which intelligent life emerges.
fc : The fraction of civilizations that develop a technology that produces detectable signs of their existence.
L : The average length of time such civilizations produce such signs (years).
There is a great deal of information online for those that want to look into the question in much more detail. But I rather like this YouTube video by Carl Sagan.
(Sorry about the funny ending to that video.)
Carl was speaking of the Milky Way. There are plenty of astronomers who believe that the universe holds many galaxies. Plus, the universe is expanding drawn ever outwards by something that is completely unknown!
What a way to think outside the box for a while!