Astronomer and scientist Carl Sagan is one of my favorite science writers. I also consider him a hero. Few people have done as much to spark public interest in the wonders of science. Few fought more bravely or openly against the ignorance and bigotry that have hindered the advance of science since its beginnings.
I’ll never forget the impact of his wonderful thirteen-part PBS television series Cosmos: A Personal Voyage. (And who, who saw it, will ever forget his unique way of saying “billions and billions,” which became comic grist for comedians like Johnny Carson and Mike Myers?)
What comes through Sagan’s writing, and the man himself, is a deep humanity, and yes, even a spirituality. This spirituality was not religious in the typical sense, but religious in the sense that Einstein said he was deeply religious:
“A knowledge of the existence of something we cannot penetrate, our perceptions of the profoundest reason and the most radiant beauty, which only in their most primitive forms are accessible to our minds: it is this knowledge and this emotion that constitute true religiosity.”
Sagan himself said, “Science is not only compatible with spirituality; it is a profound source of spirituality.” And to my mind, in few places does this spirituality and humanity come through more powerfully and eloquently than in his famous Pale Blue Dot speech, which I’ll quote in full at the end of this post.
But first, what was this “pale blue dot” that Sagan was speaking of? It is the first photograph of planet Earth taken at the very edge of our solar system. The image was taken by Voyager 1 in 1990 as it was heading out into deep space after a historic tour of the planets of our solar system.
The “pale blue dot” in photograph of the same name is planet Earth as seen from the record distance of over 3.7 billion miles. (The green oval shows Voyager 1’s approximate position when it took the photograph.)
Even light, traveling at 186,000 miles per second, takes nearly three and a half hours to reach that far. From this vast distance, Earth shows up a mere speck of light, less than pixel in size even in Voyager’s strongest camera:
Can you even make out that single pixel of blue in the red band of light? You have to have good eyes and a good computer monitor to do so! Here’s a blow-up with a circle around the pale blue dot that is in fact our entire planet:
It was Sagan’s idea to take this mind-boggling photo, so it seems only right that no one has spoken more movingly and eloquently about its historic significance. The Pale Blue Dot is one of those paradigm changing images, like the Apollo moon-landing Earth-rise image:
“Suddenly, from behind the rim of the moon, in long, slow-motion moments of immense majesty, there emerges a sparkling blue and white jewel, a light, delicate sky-blue sphere laced with slowly swirling veils of white, rising gradually like a small pearl in a thick sea of black mystery. It takes more than a moment to fully realize this is Earth . . . home.” Edgar Mitchell of Apollo 14
Photographically, the two images couldn’t be more dissimilar. Compared to the breath-taking Earth-rise image, the Pale Blue Dot seems almost a joke, a botched, grainy photograph of almost nothing—except for the almost invisible tiny blue dot. Yet, they are both the same place.
At this point, I’ll be quiet, and let Sagan himself speak to the significance of this that tiny dot:
“Consider again at that dot. That’s here, that’s home, that’s us. On it everyone you love, everyone you know, everyone you ever heard of, every human being who ever was, lived out their lives. The aggregate of our joy and suffering, thousands of confident religions, ideologies, and economic doctrines, every hunter and forager, every hero and coward, every creator and destroyer of civilization, every king and peasant, every young couple in love, every mother and father, hopeful child, inventor and explorer, every teacher of morals, every corrupt politician, every “superstar,” every “supreme leader,” every saint and sinner in the history of our species lived there – on a mote of dust suspended in a sunbeam.
The Earth is a very small stage in a vast cosmic arena. Think of the rivers of blood spilled by all those generals and emperors so that, in glory and triumph, they could become the momentary masters of a fraction of a dot. Think of the endless cruelties visited by the inhabitants of one corner of this pixel on the scarcely distinguishable inhabitants of some other corner, how frequent their misunderstandings, how eager they are to kill one another, how fervent their hatreds.
Our posturings, our imagined self-importance, the delusion that we have some privileged position in the Universe, are challenged by this point of pale light. Our planet is a lonely speck in the great enveloping cosmic dark. In our obscurity, in all this vastness, there is no hint that help will come from elsewhere to save us from ourselves.
The Earth is the only world known so far to harbor life. There is nowhere else, at least in the near future, to which our species could migrate. Visit, yes. Settle, not yet. Like it or not, for the moment the Earth is where we make our stand.
It has been said that astronomy is a humbling and character-building experience. There is perhaps no better demonstration of the folly of human conceits than this distant image of our tiny world. To me, it underscores our responsibility to deal more kindly with one another, and to preserve and cherish the pale blue dot, the only home we’ve ever known.”
There’s a beautiful and moving video of the “pale blue dot” on YouTube. It’s really worth a view.
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