Can we see a singularity, the most extreme object in the universe?
A team of scientists at the Tata Institute of Fundamental Research (TIFR), Mumbai, India, have found new ways to detect a bare or naked singularity, the most extreme object in the universe.
When the fuel of a very massive star is spent, it collapses due to its own gravitational pull and eventually becomes a very small region of arbitrarily high matter density, that is a`Singularity’, where the usual laws of physics may breakdown. If this singularity is hidden within an event horizon, which is an invisible closed surface from which nothing, not even light, can escape, then we call this object a black hole. In such a case, we cannot see the singularity and we do not need to bother about its effects. But what if the event horizon does not form? In fact, Einstein’s theory of general relativity does predict such a possibility when massive stars collapse at the end of their life-cycles. In this case, we are left with the tantalizing option of observing a naked singularity.
The most barren regions known are the far-flung corners of intergalactic space. In these vast expanses between the galaxies there is just one solitary atom per cubic meter – a diffuse haze of hydrogen gas left over from the Big Bang. On the largest scales, this material is arranged in a vast network of filamentary structures known as the “cosmic web,” its tangled strands spanning billions of light years and accounting for the majority of atoms in the universe.
Now, a team of astronomers, including UC Santa Barbara physicist Joseph Hennawi, have made the first measurements of small-scale ripples in this primeval hydrogen gas using rare double quasars. Although the regions of cosmic web they studied lie nearly 11 billion light years away, they were able to measure variations in its structure on scales 100,000 times smaller, comparable to the size of a single galaxy. The results appear in the journal Science.