The Big Bang is often described as the explosive birth of the universe – a singular moment when space, time and matter sprang into existence. But what if this was not the beginning at all? What if our universe emerged from something else – something more familiar and radical at the same time?
In a new paper, published in Physical Review D, my colleagues and I propose a striking alternative. Our calculations suggest the Big Bang was not the start of everything, but rather the outcome of a gravitational crunch or collapse that formed a very massive black hole – followed by a bounce inside it.
This idea, which we call the black hole universe, offers a radically different view of cosmic origins, yet it is grounded entirely in known physics and observations.
Today’s standard cosmological model, based on the Big Bang and cosmic inflation (the idea that the early universe rapidly blew up in size), has been remarkably successful in explaining the structure and evolution of the universe. But it comes at a price: it leaves some of the most fundamental questions unanswered.
For one, the Big Bang model begins with a singularity – a point of infinite density where the laws of physics break down. This is not just a technical glitch; it’s a deep theoretical problem that suggests we don’t really understand the beginning at all.
To explain the universe’s large-scale structure, physicists introduced a brief phase of rapid expansion into the early universe called cosmic inflation, powered by an unknown field with strange properties. Later, to explain the accelerating expansion observed today, they added another “mysterious” component: dark energy.
In short, the standard model of cosmology works well – but only by introducing new ingredients we have never observed directly. Meanwhile, the most basic questions remain open: where did everything come from? Why did it begin this way? And why is the universe so flat, smooth, and large?
New model
Our new model tackles these questions from a different angle – by looking inward instead of outward. Instead of starting with an expanding universe and trying to trace back how it began, we consider what happens when an overly dense collection of matter collapses under gravity.
This is a familiar process: stars collapse into black holes, which are among the most well-understood objects in physics. But what happens inside a black hole, beyond the event horizon from which nothing can escape, remains a mystery.
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