Scientists have claimed that evidence for past universes may exist in the night sky – namely the remnants of black holes from another universe.
As reported by New Scientist, the idea is based around something called conformal cyclic cosmology (CCC). This is the theory that our universe goes through constant cycles of Big Bangs and compressions, rather than having started from a single Big Bang.
While most of the universe would be destroyed from one cycle to the next, these scientists claim that some electromagnetic radiation could survive the recycling process. Their findings are reported on arXiv.
“What we claim we’re seeing is the final remnant after a black hole has evaporated away in the previous aeon,” University of Oxford mathematical physicist Roger Penrose, co-author on the study and co-creator of CCC theory, told New Scientist.
The evidence comes in the form of “Hawking points”, named after the late Stephen Hawking. He theorized that black holes would emit radiation known as Hawking radiation, and it’s this that Penrose and his colleagues suggest may pass from one universe to the next.
They say that Hawking points could appear in the remnant heat in the universe from the Big Bang, known as the cosmic microwave background (CMB). Hawking points would look like circles of light on the CMB map, known as B-modes.
Previously these anomalous points in the CMB were thought to be caused by either gravitational waves of interstellar dust. But Penrose and his colleagues say their theory could provide an intriguing answer, and one such Hawking point may already have been found by the BICEP2 project, which is aiming to map the CMB.
“Though seemingly problematic for cosmic inflation, the existence of such anomalous points is an implication of conformal cyclic cosmology (CCC),” the team wrote in their paper.
“Although of extremely low temperature at emission, in CCC this radiation is enormously concentrated by the conformal compression of the entire future of the black hole, resulting in a single point at the crossover into our current aeon.”
The theory of a recycling universe is not without controversy. Most of our evidence suggests that the expansion of the universe is accelerating, with the universe not being dense enough to compress back into a single point and expand again – sometimes called the Big Bounce theory.
We’ve also yet to find any evidence of Hawking radiation, let alone Hawking points. So while this is an interesting theory, there’s plenty more work to do just yet before anyone goes about claiming the definitive existence of a previous universe.