Black Holes Don't Exist

Researchers have come up with an alternative to black holes -- the remnant of supermassive stars collapsing on themselves at the end of their life to create a rip in space-time -- a singularity. Black holes, can't be directly observed, but indirect observations have put one in the centre of just about every galaxy out there. Still, there isn't a complete explanation for them. There are still unanswered questions, such as:

1. Matter crossing a black hole's event horizon is destroyed by the singularity at the centre of the black hole. Quantum mechanics however, states that information can never leave the universe.
2. Matter falling into a black hole is stretched by a black hole's gravity so that to outside observers, time stops. This violates quantum mechanics.

These questions seem to have an answer in dark energy stars (also known as gravastars) [PDF] -- stars that would appear to be, and behave just like black holes, but without violating quantum mechanics. In models of collapsing massive stars, where quantum mechanics isn't allowed to be violated, a thin quantum critical shell is created that doesn't contain a singularity, but an energy-containing vacuum. The size of the quantum critical shell depends on the mass of the collapsing star. As material from the collapsing star passes through the shell, it's converted to energy, feeding the vacuum. Unlike a black hole however, this phase transition of particles would actually cause material to escape from the vacuum due to anti-gravity. Models predict positrons, gamma rays and infrared radiation should escape -- or result from escaping particles decaying.

Looking from the outside, dark energy stars and black holes would have the same external geometries. They would have an intense gravitational pull on objects and accretion discs would form around them. The anti-gravity due to the vacuum inside the shell would have a powerful effect, suggesting that it might be responsible for the apparent accelerating expansion of the universe. Further, extremely small dark energy stars could be responsible for the effects we see as coming from dark matter. Small dark energy stars would gravitationally influence the matter around them, but would be invisible to observations. The most startling prediction of this new model happens at the other end of the size scale. The energy within the dark energy star is related to the collapsing star's size. Calculations show that the dark energy in our universe today is what we should expect from a massive dark energy star, the size of our universe. The implication being, that our universe itself may be inside a dark energy star.

Which begs the question -- just what is on the outside?