“As children, we fear the dark. Anything might be out. here. The unknown troubles us.
Ironically, it is our fate to live in the dark. This unexpected finding of science is only about three
centuries old. Head out from the Earth in any direction you choose, and—after an initial flash of
blue and a longer wait while the Sun fades—you are surrounded by blackness, punctuated only
here and there by the faint and distant stars.
Even after we are grown, the darkness retains its power to frighten us. And so there are
those who say we should not inquire too closely into who else might be living in that darkness.
Better not to know, they say.
There are 400 billion stars in the Milky Way Galaxy. Of this immense multitude, could it be
that our humdrum Sun is the only one with an inhabited planet? Maybe. Maybe the origin of life
or intelligence is exceedingly improbable. Or maybe civilizations arise all the time, but wipe
themselves out as soon as they are able.
Or, here and there, peppered across space, orbiting other suns, maybe there are worlds
something like our own, on which other beings gaze up and wonder as we do about who else
lives in the dark…Life is a comparative rarity. You can survey dozens of worlds and find that on only one of
them does life arise and evolve and persist… If we humans ever go to these
worlds, then, it will be because a nation or a consortium of them believes it to be to its
advantage—or to the advantage of the human species… In our time we’ve crossed the Solar System and sent four ships to the stars… But we continue to search for inhabitants. We can’t help it. Life
looks for life.”
— Carl Sagan in his book Pale Blue Dot: A Vision of the Human Future in Space. Carl Sagan was an American astronomer, astrophysicist, cosmologist, author, science popularizer, and science communicator in the space and natural sciences. During his lifetime, he published more than 600 scientific papers and popular articles and was author, co-author, or editor of more than 20 books. In his works, he advocated skeptical inquiry and the scientific method. He pioneered exobiology and promoted the Search for Extra-Terrestrial Intelligence (SETI).
(Watch the ingenious video from “The Sagan Series” here)