In 1931, a Belgian cosmologist named Georges Lemaître shocked the astronomy world.
Perhaps, he reasoned in a provocative paper, our utterly massive cosmic expanse might've begun as a singular, teeny tiny point some 14 billion years ago. Yet, he continued, this point probably exploded, eventually stretching out into the ginormous realm we call the universe -- a realm that's still blowing up in every direction as though it were an unpoppable balloon.
If this were true, it'd mean our universe didn't always exist. It'd mean it must've had a beginning.
Then, in 1965 -- a year before Lemaître's death -- scientists used the discovery of cosmic microwave background radiation to finally put forth undeniable evidence of this theory.
Today, we call it the Big Bang.
And on Dec. 31, the national public-service broadcaster for the Flemish community of Belgium -- the Vlaamese Radio- en Televisieomroeporganisatie, or VRT -- recovered something quite remarkable.
It's thought to be the only video of Lemaître in existence.
Better yet, this treasured roll of footage, which aired in 1964, is of an interview with the esteemed physicist where he discusses what he calls the "primitive atom hypothesis," aka the basis of his iconic Big Bang theory.
"The file for the film turned out to be misclassified and Lemaître's name had been misspelled," Kathleen Bertrem, a member of the VRT archives, said in a statement. "As a result, the interview remained untraceable for years." But one day, while a staff member was scanning a few rolls of film, he suddenly recognized Lemaître in the footage and realized he'd struck gold.
The interview itself was conducted in French -- and is available with Flemish subtitles if you want to watch it online -- but in an effort to make the film more broadly available, experts published a paper last month that provides an English translation of the nearly 20-minute clip.
"Of all the people who came up with the framework of cosmology that we're working with now, there's very few recordings of how they talked about their work," Satya Gontcho A Gontcho, a scientist at the Department of Energy's Lawrence Berkeley National Laboratory Berkeley Lab who led the translation, said in a statement. "To hear the turns of phrase and how things were discussed … it feels like peeking through time."
Reading through the entire discussion is actually quite trippy. It's incredible to see what a scientist said, verbatim, about the ideas that would eventually change the course of history, of physics, and even of human perspective.
It's also quite striking how clear, cogent and modern the discussion sounds. Almost like a podcast.
Here are some highlights
"A very long time ago, before the theory of the expansion of the universe (some 40 years ago)," Lemaître tells an interviewer, per the transcript, "we expected the universe to be static. We expected that nothing would change."
He continues to call such a concept an a priori idea, meaning no one actually had any experimental evidence to prove how the fabric of space and time was truly static. Yet, as Lemaître says (and we now know for certain) many evidentiary facts confirm the expansion of the universe.
"We realized that we had to admit change," he said. "But those who wanted for there to be no change… in a way, they would say: 'While we can only admit that it changes, it should change as little as possible.'"
On this front, Lemaître points out the beliefs of astronomer Fred Hoyle, who at the time had firmly promoted the fact that our universe is "immutable," or static. Hoyle, fascinatingly, was also the first person to use the terminology "big bang" to describe what Lemaître proposed, but he did it with the cadence of mockery. Nonetheless, the name stuck.
This isn't to say no one supported the universe expansion theory.
A solid number of physicists did, including most notably, Albert Einstein and Edwin Hubble (yes, the Hubble Space Telescope's namesake). It was, in fact, Hubble who'd shown the science community why the universe must be expanding in all directions. He'd used a massive telescope in California back in 1929 to record how distant galaxies were getting farther and farther away from us as time progressed.
In conjunction with Hubble's observations, a 1927 paper written by Lemaître eventually helped convince the majority of astronomers our universe is absolutely ballooning outward.
"Lemaître and others gave us the mathematical framework that forms the basis of our current efforts to understand our universe," said Gontcho A Gontcho.
For instance, Gontcho A Gontcho also points out how knowing the universe's expansion rate helps us study more elusive aspects of the cosmos, such as the great mystery of dark energy.
Weirdly, dark energy seems to be forcing our universe to expand far more quickly than it should, even making it go faster and faster as time progresses.
The second half of Lemaître's interview focuses not on the scientific implications of his theory but on the philosophical, even religious, implications. In addition to being a well-known cosmologist, Lemaître was a renowned Catholic priest.
The interviewer asks him, for instance, whether the idea that the universe must have a beginning holds any religious significance. Lemaître, in response, simply says, "I am not defending the primeval atom for the sake of whatever religious ulterior motive."
At this point, though, the cosmologist says further elaboration on the topic can be found in a separate interview. The interviewer pushes a bit, asking Lemaître a question about how religious authorities might react to his theories.
To this, Lemaître basically touches on how questions about the importance of when, why and how the beginning of time came to be -- religious or not -- are sort of moot. "The beginning is so unimaginable," he said, "so different from the present state of the world that such a question does not arise."
Even if God does theoretically exist, he says he doesn't believe a deity's existence would interfere with the scientific nature of astronomical theory.
"If God supports the galaxies, he acts as God," Lemaître said. "He does not act as a force that would contradict everything. It's not Voltaire's watchmaker who has to wind his clock from time to time, isn't it... [laughs]. There!"