Are White Holes Real?
Sailors have their tales about krakens and about pirates and other stuff like that. Physicists have theories about white holes: cosmic monsters that overlap the line between tall tale and actuality. Yet to be seen in the space, white holes might be only mathematical giants. But according to recent research, if a speculative theory known as loop quantum gravity is true, white holes could be not just only real but we might have already observed them. A white whole is, somewhat, the reverse of a black hole. According to Caltech physicist Sean Carroll, a black hole is a region of space where you can enter but you can never escape due to its powerful gravitational pull; a white hole is a region where you choice of leaving but you can never go back. Otherwise both share precisely the similar mathematics, precisely the same geometry. That boils down to some vital features: a singularity, where mass is pressed into a point of infinite density, and have an event horizon, the unseen “point of no return” first defined mathematically by the German physicist Karl Schwarzschild in 1916. For a black hole, the event horizon symbolizes a one-way entry; for a white hole, it’s exit-only scenario.
That is because they define universes that comprise only black holes, white holes and wormholes—no matter, radiation or even energy. Certainly, earlier research, counting Hamilton’s, proposes that anything that falls into a rotating black hole will basically plug up the wormhole, avoiding the creation of a channel to a white hole.
Einstein’s General Relativity, from which Hamilton draws his calculations, breaks down at a singularity of a black hole. Stephen Hsu, a physicist at Michigan State University in East Lansing, says “The energy density and the curvature become so large that classical gravity is not a good description of what’s happening there. Maybe a more comprehensive model of gravity—one that works as well on the quantum level as it does on bulky ones—would disprove the variability and allow for white holes.”
Certainly, a unified theory that combines gravity and quantum mechanics is one of the holy grails of modern physics. Applying one such theory to black holes, theorists Hal Haggard and Carlo Rovelli of Aix-Marseille University in France have presented that black holes could transform into white holes via a quantum procedure. In July last year, they issued their work online.
Loop quantum gravity suggests that space-time is fabricated of fundamental construction blocks formed like loops. According to Haggard and Rovelli, the loops’ limited size stops a dying star from collapsing all the way down into a point of endless bulk, and the shrinking object recoils into a white hole instead.
The black-to-white transformation could resolve a nettlesome puzzle known as the black hole information paradox. The idea that information can be destroyed is abomination in physics, and general relativity states that anything, counting information, that drops into a black hole can never escape. It does not mean that s black holes only act as protected safes for any information they slurp up, but Stephen Hawking presented 40 years ago that black holes essentially evaporate with time. That directed to the alarming prospect that the information confined within black hole could be lost too, generating a discussion that rages to this day.
It is far from clear whether loop quantum gravity is an exact explanation of reality. The only sign we get of white holes might be in only models that we create in labs and kitchen sinks. But that’s okay. Just thinking about these theoretical cosmic creatures can advance physicists’ insight, even if the actual world is confused and not like those precise conditions. That’s the way in which white holes are very valuable for a physicists.
Are White Holes Real? Reviewed by Umer Abrar on 1/26/2015 Rating: