A new scientific study to explain how black holes could exist has suggested that they are actually quite like giant balls of string.
Black holes are areas of space-time which are so dense that nothing can escape them – whether it is matter or energy.
But this raises a paradox between two methods of understanding the universe, quantum mechanics and general relativity.
Some physicists have attempted to answer this paradox by suggesting the existence of a burning "firewall" around the edge of black holes, which destroy any objects before they reach a black hole's surface.
But a team from Ohio State University has potentially disproved this by calculating what would happen if an electron fell into a black hole, in a paper published in the Journal of High Energy Physics.
Professor Samir Mathur said: "The probability of the electron hitting a photon from the radiation and burning up is negligible, dropping even further if one considers larger black holes known to exist in space.
"What we've shown in this new study is a flaw in the firewall argument," Professor Mathur added.
After months of intense mathematical analysis, Professor Mathur and his team have established the figures challenging the firewall theory.
Their work uses string theory – a scientific model of the universe which considers everything to be composed of subatomic string-like tubes of energy.
String theory is a way to tie quantum mechanics (the mechanics of particles even smaller than atoms) and Albert Einstein's theory of relativity, which says that all objects fall the same way, despite their mass or composition.
Professor Mathur said he has always been sceptical of the firewall theory, preferring the model of black holes as balls of string, or fuzzballs.
"The question is, 'where does the black hole grab you?' We think that as a person approaches the horizon, the fuzzball surface grows to meet it before it has a chance to reach the hottest part of the radiation, and this is a crucial finding in this new physics paper that invalidates the firewall argument," he said.
"Once a person falling into the black hole is tangled up in strings, there's no easy way to decide what he will feel.
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"The firewall argument had seemed like a quick way to prove that something falling through the horizon burns up.
"But we now see that there cannot be any such quick argument; what happens can only be decided by detailed calculations in string theory," Professor Mathur added.