Imagine an entity that devours everything. Yes, everything. A concentration of all matter, space, celestial bodies, and most importantly, light. This description can only describe the cosmic marvels called black holes. The gravitational pull of the holes are so dense that even light is trapped on its way to the density called a singularity. Thirty years ago, Stephen Hawking’s theory claimed that black holes would evaporate over time due to radiation. The “Hawking Radiation”: a theory that radiation would be emitted from black holes on a quantum level which would eventually cause the holes to diminish over time due to their finite and non-zero temperature and entropy. What does all this equate to and why is it important for us to know this? The answer lies in the quest for man’s existence. A mystery we have wanted to solve since the beginning of time. Scientists have developed an artificial black hole to test the Hawking Radiation. The result, if concurred would not only, finally, award Hawking with a Nobel prize, but also allow us to be one step closer to understanding our cosmic beginnings.
What is time? It is a combination of a measurement of two events in cosmic relativity and a measure of distance. Days, years and centuries only measure the distance the earth has travelled around the sun. So could the space time continuum vanish into black holes? It is very probable and highly likely. A gravitational pull so immense that light itself is swallowed whole. The thought of that is mind boggling. Black holes would be able to devour hundreds of small galaxies like ours and still have room for desert. There are theories that claim that our universe was a result of such a singularity which started with the entire universe concentrated into a size of a pin’s head. The energies were such that it caused the mass to explode into small tiny pieces which we later developed into galaxies that we know today. Could this have resulted from what was initially a black hole that sucked everything into a singular piece of cosmic dynamite? That would mean that there might have been multiple “big bangs” over the course of universe “lifetimes”. Hawking’s radiation suggests otherwise.
Hawking’s Radiation overview
At the event horizon of a black hole, a particle must accelerate to keep from falling in (let’s take a light particle for example: the photon). An accelerating photon will see a thermal bath of particles that pop out of the black hole horizon, turn around, and accelerate back in. The local thermal equilibrium implies that the consistent extension of this local thermal bath has a finite temperature at infinity, which implies that some of these particles emitted by the horizon are not reabsorbed and become outgoing Hawking Radiation. In layman’s terms, at a quantum level, there are particles that appear spontaneously out of empty space. There is a particle that appears with its antiparticle. They only exist briefly before destroying each other. With this in mind, Hawking proposed that if particles were created at the horizon of a black hole, one would be destroyed whilst one would be left outside. To an observer, this particle would be visible as radiation. Over time, this radiation would cause the black hole to evaporate.
Making black holes
Scientists have managed to manifest a black hole that traps sound to test the Hawking radiation’s principles. A team, led by Jeff Steinhauer of Technion-Israel Institute of Technology has manufactured this experiment to test the actualities using sound in a medium. The scientists cooled around 100,000 charged rubidium atoms to a few billionths of a degree above absolute zero. These particles were then trapped using a magnetic field. Using a laser, they then created a well of electric potential that attracted the atoms and caused them to zip across the well faster than the speed of sound in the material. TA supersonic flow was created which lasted eight milliseconds, consequently developing an acoustic black hole capable of trapping sound. The implications of this experiment could lead to the development of testing Hawking Radiation.
Conclusively, the development of Hawking Radiation, from theory to possible fact could lead to answers about cosmic bodies like black holes. This development could result in us getting closer to the answer about our existence. Radiation caused by the big bang can still be heard to date. The more pertinent question is not why we are here but how we got here. As pieces of the puzzle begin to fit, one can’t help but think of possibilities of time travel, endless energy resources, and the overall development of mankind. We will definitely be able to study our galaxy and others around us better. Space, it seems, is the final frontier.