Updated: Jan 26, 2022
Let’s talk about the science of fiction.
You know his name. You’ve read his stories. But did you know Isaac Asimov imagined an alternative explanation for black holes?
A name easily recognized among readers, Isaac Asimov was one of the most prolific science fiction authors of all time, with an extensive list of awards and accolades to attest to his reputation. In life, he was one of the “Big Three” sci-fi giants, and until this day his stories are a must-read for the fans of the genre.
In 1972, the father of the Foundation series published the Nebula and Hugo awards winner novel The Gods Themselves, a story born from a challenge. Author Robert Silverberg dared Asimov to write a story about a non-existent isotope, plutonium 186, and the result was an alternative theory to the existence of black holes.
I should warn you: SPOILERS AHEAD for The Gods Themselves.
But first, the science.
During the fifties, astronomers observed radio sources with no corresponding visible objects that could emit those strong signals. In 1964, these received the name of quasars, which stands for quasi-stellar objects. In that same year, the astrophysicists Yacob Zel’dovich and Edwin E. Salpeter independently suggested that such radio sources were in fact gravitationally collapsed objects—astronomical bodies so dense they close themselves within a region from where nothing can escape, not even the fastest thing in the universe: light. If you are thinking black holes, you are spot on!
It was only in 1967, though, that the completely gravitationally collapsed objects received the name black holes. Although the seed of the idea of a black hole can be found in 1916, right after the birth of Einstein’s general theory of relativity, or even traced back to the end of the XVIII century, when they were called dark stars, the proposal that such objects could indeed exist was too bizarre; on top of being disconnected from observations. No wonder most of the greatest minds of the time dismissed it. It remained an obscure theory for about 50 years after the birth of general relativity.
Quasars were the first observed objects that fit the description of black holes. Only then the theory of their existence gained traction. After their baptism, black holes were introduced to a wider public in 1971 in an article on Physics Today appropriately titled Introducing Black Holes. Around the same time, Isaac Asimov was writing The Gods Themselves.
Asimov was most likely unaware of the existence of black holes when he fictionalized an explanation for quasars. In his futuristic world, he wrote about quasars, “In the century and a half since they were discovered, astronomers have still failed to account for their sources of energy. Nothing in this Universe will account for it; nothing.” (The Gods Themselves, p.55) That is, until an electron pump appeared out of nowhere. This pump was a connection between our world and a parallel universe. In this para-Universe, the laws of physics differed from ours in such a way that the isotope plutonium 186 was stable there (do you still remember the challenge?).
In the story, this pump is worshiped as an infinite source of energy. It pumps electrons from the para-Universe to ours, and in return it pumps our positrons into the para-Universe. It seemed a great trade until one realized that there are more than electrons leaking from the para-Universe. The laws of physics around the pump “weakens” because the para-Universe’s physics merges with ours. It is an infinitesimally small change, but when amounted to millions of years, it has a devastating local effect: the explosion of nearby stars. Because the laws of physics are different in that region, from afar the explosion of a regular star like the sun would be perceived as a quasar. Brilliant!
Instead of black holes, Asimov imagined a connection with a different universe with different laws of physics that resulted in a local disaster. Well, we don’t know what’s inside a black hole. It is a region completely apart from our universe. A parallel reality, one might say. And it constantly "pumps" matter into ours in the form of Hawking radiation. Who knows? Maybe Asimov was onto something.