Was There Nothing Before the Big Bang? Roger Penrose’s Cyclic Universe, Explained
Quick answer: Nobel laureate Roger Penrose argues that our Big Bang did not come out of nothing. In his conformal cyclic cosmology (CCC), the universe passes through a possibly endless series of “aeons.” When an aeon has expanded for so long that its black holes have evaporated and only radiation is left, it loses any physical sense of scale, and its infinitely stretched future becomes, mathematically, the Big Bang of the next aeon. So in CCC there is no empty “nothing” before the Big Bang, only the remote future of an earlier universe. The idea is a serious, peer-reviewed proposal, but it remains a minority view: the observational evidence Penrose and his colleagues have reported has been disputed, and it is not part of the standard model of cosmology.
Clips of Penrose saying there was “something” before the Big Bang circulate widely online, often with claims he never made. Here is what his theory actually says, the evidence for and against it, and where the science stands today.
Who is Roger Penrose?
Penrose is a British mathematical physicist and professor emeritus at the University of Oxford. He received half of the 2020 Nobel Prize in Physics “for the discovery that black hole formation is a robust prediction of the general theory of relativity.” The other half went to Reinhard Genzel and Andrea Ghez for finding the supermassive black hole at the centre of our galaxy.
His cosmological ideas are a separate matter from that Nobel-winning work. Penrose has been open about this. “This is my cosmology scheme, which I’m having trouble persuading the cosmologists about,” he said in his official Nobel interview.
What is conformal cyclic cosmology?
Penrose described the idea for a general audience in his 2010 book Cycles of Time. According to a 2025 paper by Penrose and Krzysztof Meissner of the University of Warsaw, “The Physics of Conformal Cyclic Cosmology”, the theory holds that the whole conventional history of the universe is “but one cosmic aeon of an unending sequence of such aeons.” The far future of each aeon “joins essentially smoothly” to the Big Bang of the next.
How a universe “forgets how big it is”
The argument goes like this. Our universe is expanding at an accelerating rate. In the extremely remote future, stars will have died and black holes, which hold most of the universe’s disorder, or entropy, will have evaporated through Hawking radiation. In his Nobel interview, Penrose cited an estimate of roughly a thousand googol years (a 1 followed by 103 zeros) for the largest ones to disappear.
What remains would be mostly massless radiation, such as photons. Massless particles do not experience time in the ordinary way, and without mass there is nothing to act as a clock or a ruler. “When the universe is rid of pretty well all its matter, it in a certain sense forgets how big it is,” Penrose said. “It in effect becomes the big bang of the next aeon.”
This is where the word “conformal” comes in. Conformal geometry keeps shapes and angles but ignores size. Penrose’s insight is that, in this sense, an endlessly expanded, nearly empty universe and a tiny, hot, dense Big Bang can be matched to each other.
No inflation required
Standard cosmology includes inflation, a burst of exponential expansion in the first tiny fraction of a second. Penrose does not accept it. In his view, the previous aeon’s late, exponential expansion plays the role that inflation plays in the standard picture, smoothing the universe before our Big Bang.
So is there really no “nothing”?
Within CCC, yes: there is never a point at which the universe emerges from nothing, because every Big Bang is the continuation of an earlier aeon. That is a striking change of mind for Penrose. In an interview for Closer to Truth, he said he would once have answered that asking what came before the Big Bang was meaningless, since there was no time before it. “I’ve come to the view that there was something before the Big Bang,” he said.
Many physicists still hold that the question may have no answer, or that there is no good evidence for anything before the Big Bang. Others explore different pre-Big Bang scenarios. CCC is one carefully worked-out option among several, not a settled fact.
The evidence Penrose has claimed
If earlier aeons existed, they might have left faint marks on the oldest light we can see, the cosmic microwave background (CMB), released about 380,000 years after the Big Bang.
Rings in the sky
In 2010, Penrose and physicist Vahe Gurzadyan reported concentric circles of unusually low temperature variation in the CMB, which they linked to black hole collisions in a previous aeon. As a later review of the debate notes, those claims were quickly disputed by three independent analyses, which found the original study had not properly accounted for ordinary structure in the CMB.
“Hawking points”
In 2020, Penrose, Daniel An, Krzysztof Meissner and PaweÅ‚ Nurowski published a paper in the Monthly Notices of the Royal Astronomical Society reporting “anomalous circular spots” of raised temperature, about 3 to 4 degrees across, in data from both the Planck and WMAP satellites. They interpreted them as “Hawking points”: the energy of supermassive black holes that evaporated in the aeon before ours. Penrose has put the confidence of that signal at 99.98%.
Why most cosmologists are not convinced
Cosmologists Dylan Jow and Douglas Scott re-examined the Hawking-point claim in the Journal of Cosmology and Astroparticle Physics in 2020. When they accounted for the fact that the search had tried many possible ring sizes, the excess in the Planck data dropped to about 87% confidence, “little more than 1σ.” Simulated skies with no Hawking points at all produced a stronger signal than the real data 13% of the time. They concluded there is “no statistically significant evidence for the presence of Hawking points in the CMB.”
There are theoretical gaps too. How the physics carries over from one aeon to the next has long been considered “somewhat problematic,” as Meissner and Penrose themselves wrote in 2025, when they proposed a new mechanism involving an era dominated by gravitational waves. A 2023 study in General Relativity and Gravitation called the choice of the mathematical factor that links aeons “a major open problem.” And a 2026 paper in the Journal of Mathematical Physics built a well-behaved simplified model of the transition while stating plainly that it “does not claim to prove the full CCC proposal.”
What the theory does not say
Some viral posts present Penrose’s cosmology as proof that the soul is eternal or that consciousness survives death. CCC says nothing of the kind. It is a model of spacetime geometry, matter and radiation. In Penrose’s own description, each aeon “forgets” its scale, and the only traces it could pass on are faint physical imprints in the next universe’s background radiation.
For more from the edge of astronomy, read about the first green star ever found, the coldest exoplanet ever photographed by Webb and the medieval supernova our ancestors saw explode in 1181. More in our Science section.
Frequently asked questions
What is conformal cyclic cosmology?
It is a model proposed by Roger Penrose in which the universe goes through a possibly endless sequence of aeons. The remote, nearly empty future of each aeon is mathematically matched to the Big Bang of the next, so our Big Bang would have grown out of an earlier universe.
Did Roger Penrose say there was something before the Big Bang?
Yes. Penrose has said he came to the view that there was something before the Big Bang: in his theory, the far future of a previous aeon. He has also acknowledged that most cosmologists are not persuaded.
What are Hawking points?
They are warm spots in the cosmic microwave background that Penrose and colleagues reported in 2020 and interpreted as the energy of black holes that evaporated in the aeon before ours. An independent 2020 analysis found the signal was not statistically significant.
Is there evidence for conformal cyclic cosmology?
Not convincing evidence so far. Claimed signals in the cosmic microwave background, first low-variance rings and later Hawking points, have been disputed by independent analyses. CCC remains an unconfirmed hypothesis outside the standard model of cosmology.
Does Penrose’s theory mean the soul is eternal?
No. Conformal cyclic cosmology is a physical model of spacetime, matter and radiation. It makes no claims about souls, consciousness or life after death.
Sources: NobelPrize.org; Roger Penrose, Nobel interview; Meissner & Penrose (2025); An et al., MNRAS (2020); Jow & Scott, JCAP (2020); Markwell & Stevens, General Relativity and Gravitation (2023); Mulero-MartÃnez, Journal of Mathematical Physics (2026); Aeon / Closer to Truth.
Featured image: nine-year map of the cosmic microwave background, NASA / WMAP Science Team, public domain, via Wikimedia Commons (background extended for display).