What if the Big Bang was not the start? New research suggests that it may have taken place inside a black hole
THE Big Bang is often described as the explosive birth of the universe – a singular moment when space, time and matter have appeared. But what happens if it was not at all the start? What if our universe emerged from something else – something more familiar and radical at the same time?
In a new newspaper, Posted in Physical Review DMy colleagues and I offer a striking alternative. Our calculations suggest that the big bang was not the beginning of everything, but rather the result of a crunch or a gravitational collapse which formed a very massive black hole – Followed by a rebound inside.
This idea, which we call the universe of black holes, offers a radically different vision of cosmic origins, but it is entirely anchored in known physics and observations.
Today standard cosmological modelBased on Big Bang inflation and Cosmic (the idea that the early universe quickly exploded), remarkably succeeded in explaining the structure and evolution of the universe. But that has a price: he leaves some of the most fundamental questions unanswered.
On the one hand, the Big Bang model begins with a singularity – an infinite density point where the laws of physics decompose. It is not only a technical problem; It is a deep theoretical problem that suggests that we do not understand the start at all.
To explain the large -scale structure of the universe, physicists introduced a brief phase of rapid expansion in the early universe called cosmic inflationFood by an unknown field with strange properties. Later, to explain the accelerated expansion observed today, they added another “mysterious” component: dark energy.
In relation: 5 Fascinating facts on the Big Bang, the theory that defines the history of the universe
In short, the standard cosmology model works well – but only By introducing new ingredients We have never observed directly. Meanwhile, the most basic questions remain open: where everything came from? Why did it start in this way? And why is the universe so flat, smooth and large?
New model
Our new model addresses these questions from a different angle – looking inward instead of the outside. Instead of starting with an expanding universe and trying to trace how it started, we consider what is happening when a collection too dense of matter collapses under gravity.
This is a familiar process: the stars collapse in black holes, which are among the most well understood objects in physics. But what is happening inside a black hole, beyond the horizon of the event from which nothing can escape, remains a mystery.
In 1965, British physicist Roger Penrose proved that under very general conditions, Gravitational collapse must lead to a singularity. This result, extended by the late British physicist Stephen Hawking and othersunderlies the idea that singularities – like that of Big Bang – are inevitable.
The idea helped to win in Penrose a part of the Nobel Prize for Physics 2020 and a world-class best-seller of Hawking Inspired A brief history of time: from big bang to black holes. But there is a warning. These “theorems of singularity” are based on “classic physical” which describes ordinary macroscopic objects. If we include the effects of quantum mechanics, which governs the tiny microcosmos of atoms and particles, as we owe to extreme densities, history can change.
In Our new paperWe show that the gravitational collapse does not have to end with a singularity. We find an exact analytical solution – a mathematical result without approximations. Our mathematics show that when we approach the potential singularity, the size of the universe changes as a (hyperbolic) function of cosmic time.
This simple mathematical solution describes how a cloud of collapsed matter can reach a high density state, then bounce back, bouncing outward in a new expansion phase.
But how is it that penrose theorems do not prohibit such results? Everything is due to a rule called Quantum exclusion principlewhich indicates that no identical particles called farmions can occupy the same quantum state (like the angular moment, or “spin”).
And we show that this rule prevents the particles of matter which collapse from being tight indefinitely. As a result, the collapse ends and is reversed. The rebound is not only possible – it is inevitable in the right conditions.
Above all, this rebound occurs entirely in the context of general relativity, which applies to large scales such as stars and galaxies, combined with the basic principles of quantum mechanics – no exotic fields, additional dimensions or required speculative physics.
What emerges on the other side of the rebound is a remarkably universe like ours. Even more surprising, the rebound naturally produces the two distinct phases of accelerated expansion – inflation and dark energy – not by a hypothetical field but by the physics of the rebound itself.
Testable predictions
One of the forces of this model is that it makes testable predictions. He predicts a small but not zero of positive spatial curvature – which means the universe is not exactly flatbut slightly curved, like the surface of the Earth.
It is simply a relic of small initial surality that triggered the collapse. If future observations, like the Euclide missionConfirm a small positive curvature, it would be a strong clue that our universe indeed emerges from such a rebound. It also predictions on the expansion rate of the current universe, which has already been verified.
This model makes more than solving technical problems with standard cosmology. It could also shed new light on other deep mysteries in our understanding of the early universe – such as the origin of supermassive black holes, the nature of dark matter or hierarchical formation and the evolution of galaxies.
These questions will be explored by future space missions such as ArrokihsWho will study diffuse characteristics such as stellar halos (a spherical structure of stars and globular clusters surrounding galaxies) and satellite galaxies (smaller galaxies that orbit larger) which are difficult to detect with traditional telescopes of the earth and will help us to understand the dark matter and the evolution of galaxy.
These phenomena could also be linked to relic compact objects – such as black holes – which were formed during the phase of collapsing and survived the rebound.
The Black Hole universe also offers a new perspective in our place in the cosmos. In this context, our whole observable universe is inside a black hole formed in a larger “parent” universe.
We are not special, any more than the earth in the vision of the geocentric world which led Galileo (the astronomer who suggested that the earth turns around the sun in the 15th and 17th centuries) to be placed in residence.
We do not see the birth of everything, but rather the continuation of a cosmic cycle – in the shape of gravity, quantum mechanics and deep interconnections between them.
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