Understanding the darkness — maybe a poet does that better than a scientist? Everyone probably knows that scientists sometimes are active in the field of humanities, there are scientists who have made important humanistic contributions. But not everyone knows that there are also humanists who have solved difficult scientific problems.
Sometimes the easiest questions are the most difficult:
Why is the sky black at night?
If the universe is infinitely large and there are infinitely many stars that are randomly placed, then there should be a star at every point in the sky and the sky would be completely covered by stars. The night sky should not be black but filled with stars without spaces, a sparkling, radiant, silvery-white night.
It sounds like a simple question; everybody knows that when the sun has set the sky is dark black. But the question is not simple the answer is far from obvious. Instead, it puzzled scientists for hundreds of years.
The riddle is called Olbers’ paradox, named after Henrich Wilhelm Olbers a German amateur astronomer who in 1823 wrote an article in which he formulated the paradox. His proposed solution was that there would be some type of black cloud that absorbed radiation and thereby hid some of the stars from us. But there are no such black clouds in the skies.
The problem is very old, it puzzled the first modern astronomers. In England in the 16th century worked Thomas Digges, a careful explorer of the starry sky. He is probably the first to describe the problem and provided a possible solution. Digges imagined that the distant stars would somehow become so faint that they could not be seen on Earth. But light cannot disappear on the way towards earth.
Even the basic conditions have been questioned — the universe may not be infinite. The great astronomer Johannes Kepler, who solved the problem of the planets’ orbits and who managed to calculate that the planets move in elliptical orbits around the sun, said in the early 17th century that the dark sky was proof that the universe is not infinite. But the universe is infinitely large.
Edgar Allan Poe
The first viable theory for Olbers’ paradox came from someone who may have known much about darkness but who was not a scientist or astronomer. The theory came from the American author and poet Edgar Allan Poe. Poe was born 1809 in Boston and had a dark and black life and died only 40 years old under unclear circumstances, probably in “delirium tremens”. In the last years of his short life, especially after the death of his young wife in tuberculosis, he lived an intense life with both alcohol and drugs but also working with an intensive, almost philosophical, scientific work that he managed to publish in 1848, just one year before his death.
The book was called “Eureka — a prose poem”. Poe called the text an essay on the material and spiritual universe and believed that the book would revolutionize the world, he tried to get the publisher to print 50,000 copies in a first edition. But there were only 500 copies printed. Eureka is a small, strange book, a difficult-to-read poetic and philosophical text, sometimes almost like a physics book containing an advanced cosmological theory. The name “Eureka” comes from the Ancient Greek word meaning “I have found (it)”
Poe is for many probably best known as a mystery writer and the father of detective story literature, but he perceived himself as a poet and published a large number of poems. And he was much more than an early detective story writer, both his poems and his ideas explored dark sides of the soul in an innovative and at the same time aesthetic way. In France, Charles Baudelaire became the one who introduced and translated him. Baudelaire wrote in a letter to Théophile Thoré in 1864:
“La première fois que j’ai ouvert un livre de lui, j’ai vu, avec épouvante et ravissement, non seulement les sujets rêves par moi, mais des phrases, pensées par moi, et écrites par lui, vingt ans auparavant.”
“The first time I opened a book he had written, I saw with equal measures of horror and fascination, not just the things that I had dreamed of, but actual phrases that I had designed and that he had penned twenty years earlier.”
In Eureka, Poe describes a kind of pulsating universe very differently from the Newtonian non-expanding universe of the time. Poe suggests an explanation for the night’s dark sky. He writes:
“Were the succession of stars endless, then the background of the sky would present us a uniform luminosity, like that displayed by the Galaxy — since there could be absolutely no point, in all that background, at which would not exist a star. The only mode, therefore, in which, under such a state of affairs, we could comprehend the voids which our telescopes find in innumerable directions, would be by supposing the distance of the invisible background so immense that no ray from it has yet been able to reach us at all”.
That is, the dark spaces are filled with stars, but which are so far away that the light from them has not yet reached us, because the universe is too young. Which is exactly the answer that scientists today, 150 years and several scientific revolutions later, believe is the solution to Olbers’ paradox.
For scientists, it would take some years before they came up with what Poe had already figured out. In 1901, Lord Kelvin published an article in which he calculated that we would need to see a couple of hundred billion years into space for the sky to be covered by stars, and because the universe is not that old, we cannot see stars at every point the night sky.
So, when you look up at the black sky of the night the next time, remember that it is the youth of the universe that you see between the stars.
A darkness that was first understood by a poet.