What happens in a black hole?
Black holes are certainly one of the greatest mysteries in our universe — infinitely dense and infinitely small, these strange phenomena have puzzled physicists for over a century.
For a while now, we have been pretty sure of what a black hole is, how it acts, and how it’s formed:
When a supermassive star begins to run out of fuel (that is, elements less heavy than iron which fuse together to release radiation), the star stops releasing radiation, which is supposed to combat the force of gravity pushing in on itself. As the inwards force of gravity becomes larger than the outwards force of radiation, the forces become unbalanced, and in a fraction of a second the star collapses in a supernova. If the star is large enough, it will leave behind a black hole.
Thanks to the genius of Professor Stephen Hawking, we also know that black holes can shrink over time, as (theoretically) they should release Hawking Radiation and evaporate. Hawking radiation is the the process of a black trapping one particle from a particle-antiparticle pair, which has been spontaneously produced near the event horizon.
As much as we can learn about the edge of a black hole, we are still asking the questions: “what is a black hole?” and “what is it made of?” For now, physicists are calling the centre of a black hole “the singularity,” but, to be blunt, we have no idea what this is. The singularity could be infinitely dense, with no surface area and no volume, housing an incredibly large mass in an infinitely small space. But we just don’t know.
The singularity curves space-time infinitely, so there is no way out; you would have to be travelling greater than the speed of light to escape a black hole, which according to Albert Einstein, is sadly impossible. At the singularity, time comes to a stop, and the force of gravity is unimaginable; if you were to fall into a black hole, the difference in the gravity at different places in your body would tear you apart, cell from cell (if you say this while smiling it doesn’t seem so morbid).
Unfortunately, we will probably never be able to fully describe the singularity at the centre of a black hole; however, interesting new theories on quantum entanglement may offer a closer look at how black holes function.
Quantum entanglement is the theory that some pairs of particles share a special connection (actually more of a correlation), where the behaviour of one particle can be used to determine the behaviour or the other.
By applying this to our black hole problem, if one entangled particle was to fall into the black hole, whilst the other could escape (and be examined), we may be able to find out what happened to the first one. We simply have no idea whether the particles would remain entangled, or what would happen if the black hole evaporated.
Sadly, we are not even sure if this clever idea would even give any evidence to describe the nature of a black hole, as many physicists would say that the entangled particle we can examine would not appear any different to a regular particle. The principle of “monogamy of entanglement” is also against this theory; the outgoing particle must be entangled with the infalling particle, but also all past Hawking Radiation (the principle states that a particle cannot be entangled with two particles independently). Other experts are more optimistic.
It will be hugely interesting to uncover the secrets behind black holes, which may well happen within our lifetimes, as we can expect the first photographs of a black hole, captured by the Event Horizon Telescope, later in 2019. The future of astrophysics looks to be very promising.
