In the early nineties, Professor Stephen Hawking challenged his fellow physicists Preskill and Thorne to bet on the existence of naked singularities. Hawking was certain he would win this lucrative $100 bet until Matt Choptuik of University of British Columbia used numerical simulations to prove that naked singularities can exist in four dimensional fine tuned conditions. Hawking might have lost the bet but he definitely had succeeded in giving a fillip to the researchers in their grand search for an elusive bare black hole.
In India, Dr Chandrachur Chakraborty from Tata Institute of Fundamental Research, Mumbai (TIFR) along with Prashant Kocherlakota, Professor Sudip Bhattacharyya and Professor Pankaj Joshi carried out the precession recurrence (explained below) of a whirligig going around a black hole. Professor Chakraborty and his team devised an ingenious technique which suggested that it is possible to detect a naked singularity by measuring the precession frequencies of the matter that is being siphoned by the black hole.
The idea behind this assumption was that the orbital plane frequency of matter increases as it approaches a black hole which, in case of a naked singularity can become as low as zero. These low frequencies measurements indicate naked singularities.
Why Are These Singularities Naked And Elusive
A singularity is that point in space where whole mass of the dying star had been crushed and boxed into a single point making it infinitely dense. But singularities are usually enveloped with an event horizon. And, even before one starts to think about pulling off a Cooper and land in a five dimensional tesseract, they should be warned about the insane gravitational pull of the black holes. The pull is so intense that even light is not allowed to escape from it and an average human being will be extruded into a infinitesimal spaghetti. Yes, that’s what you get when a star of million kilometers diameter, collapses into the size of a ping pong ball.
Next, there are speculations about naked singularities; the ones without event horizons.
Singularity is not the same as a black hole but it is what causes the black hole to appear in the first place. Singularities are characterised by infinite density and zero volume. As weird as it may sound but that’s astrophysics in a nutshell.
The conjecture of cosmic censorship says that it is impossible for a singularity to exist without a black hole around it. In other words, according to mathematical physicist Roger Penrose, it is impossible for naked singularities to exist.
But, the physicists at TIFR in collaboration with Institute of Mathematics of Polish Academy of Sciences have illustrated how to detect a naked singularity.
TIFR’s 2 Step Plan To Prove Existence Of Naked Singularities
A rotating body (gyroscope in this case) is said to be precessing, when the axis of its rotation itself has changed its orientation and is precessing about a second axis. This phenomena can be observed in astronomical bodies like planets where there is a steady change in the axis of rotation; commonly known as precession of the equinoxes. With this knowledge of rotating bodies, the researchers observed that:
- If the precession frequency of the rotating body fluctuates vigorously between two observed points, then this rotating body is assumed to be a regular black hole.
- In other case, if the frequency changes are consistent, it indicates the existence of a bare black hole.
So, according to the researchers at TIFR, if this precession of a rotating body is measured then the frequency of its precession will give away the nature of the rotating body.
The rotating body, a gyroscope needs to be in the vicinity of the black hole to carry out the experiment which doesn’t seem plausible given the fact that the closest one is 1600 light years away.
The knowledge of naked singularities would allow us to study both quantum mechanics and general relativity; the science of the very small and the science of the very large bodies respectively. This is important because these two theories appear to work perfect independently but induce chaos when brought under the same roof.
Few contemporary Indian Astrophysicists are still skeptical about this model. “If singularity remains naked, the luminosity would be huge, about 16 times higher than what we see and would not go undetected. The only solution is that the singularity is quickly covered by the event horizon keeping the luminosity trapped inside,” says Sandip Chakrabarti from the SN Bose National Centre for Basic Sciences in Kolkata.
Addressing this mystery will either create ripples in the fabric of laws of physics or will verify Hawking’s quip that, “Nature abhors naked singularity.”