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Black holes are 'portals to other universes,' according to new quantum results
Posted: 30 Nov 2013 01:53 PM PST

Photo: Phil Plait (Preview)
/Flickr

According to Albert Einstein's theory of general relativity, black holes are uninhabitable chasms of space-time that end in a "singularity," or a mass of infinite density. It's a place so bleak that even the laws of physics break down there. But what if black holes aren't so forbidding? What if they are instead some kind of intergalactic stargate, or maybe even a passageway into a whole other universe?

It may sound like the premise for a clever science-fiction movie, but new calculations by quantum physicists now suggest that the stargate idea might actually be the better theory. According to the startling new results, black holes do not culminate in a singularity. Rather, they represent "portals to other universes," reports New Scientist.

This new theory is based on a concept known as 'loop quantum gravity' (or LQG). It was first formulated as a way of merging standard quantum mechanics and standard general relativity, in order to remedy incompatibilities between the two fields. Basically, LQG proposes that spacetime is granular, or atomic, in nature; It is made up of miniscule, indivisible chunks about the same size as the Planck length — which roughly amounts to 10-35 meters in size.

Researchers Jorge Pullin from Lousiana State University, and Rodolfo Gambini from the University of the Republic in Montevideo, Uruguay, crunched the numbers to see what would happen inside a black hole under the parameters of LQG. What they found was far different from what happens according to general relativity alone: there was no singularity. Instead, just as the black hole began to squeeze tight, it suddenly loosened its grip again, as if a door was being opened.

It might help to conceptualize exactly what this means if you imagine yourself traveling into a black hole. Under general relativity, falling into a black hole is, in some ways, much like falling into a very deep pit that has a bottom, only instead of hitting the bottom, you get pressed into a single point — a singularity — of infinite density. With both the deep pit and the black hole, there is no "other side." The bottom stops your fall through the pit, and the singularity "stops" your fall through the black hole (or at least, at the singularity it no longer makes sense to say you're "falling").

Your experience would be much different traveling into a black hole according to LQG, however. At first you might not notice the difference: gravity would increase rapidly. But just as you were nearing what ought to be the black hole's core — just as you're expecting to be squashed into the singularity — gravity would instead begin to decrease. It would be as if you were swallowed, only to be spit out on the other side.

In other words, LQG black holes are less like holes and more like tunnels, or passageways. But passageways to where? According to the researchers, they could be shortcuts to other parts of our universe. Or they could be portals to other universes entirely.

Interestingly, this same principle can be applied to the Big Bang. According to conventional theory, the Big Bang started with a singularity. But if time is rewound according to LQG instead, the universe does not begin with a singularity. Rather, it collapses into a sort of tunnel, which leads into another, older universe. This has been used as evidence for one of the Big Bang's competing theories: the Big Bounce.

Scientists don't have enough evidence to decide whether this new theory is actually true, but LQG does have one thing going for it: it's more beautiful. Or rather, it avoids certain paradoxes that conventional theories do not. For instance, it avoids the black hole information paradox. According to relativity, the singularity inside a black hole operates as a sort of firewall, which means that information that gets swallowed by the black hole gets lost forever. Information loss, however, is not possible according to quantum physics.

Since LQG black holes have no singularity, that information need not be lost.
"Information doesn't disappear, it leaks out," said Jorge Pullin.

Source: MMN
http://www.themindunleashed.org/

Astronomers discover biggest black holes ever

Scientists have discovered the two biggest black holes ever observed, each with a mass billions of times greater than the Sun's, according to a study published Monday.

The two giants are located in the heart of a pair of galaxies several hundred million light years from Earth, said the study in scientific journal Nature.

Each black hole is estimated to have a mass about 10 billion times greater than the sun, dwarfing the previously largest-known black hole, which has a mass of 6.3 billion suns.

The University of California, Berkeley, team led by Nicholas McConnell and Chung-Pei Ma said one black hole is located in NGC 3842, the brightest of a cluster of galaxies about 320 million light years from Earth.

The second hole is of "comparable or greater mass" and is located in NGC 4889, the brightest galaxy in the Coma cluster, about 335 million light years away.

"These two black holes are significantly more massive than predicted," the astronomers wrote.
They said their calculations suggest that different evolutionary processes influence the growth of the largest galaxies and their black holes than in smaller galaxies.

Astronomers have long supposed that since the universe began it has harboured black holes with a mass the size of the two newly found giants.

These cosmic gluttons grow in tandem with their galaxies, slurping up gases, planets and stars.
"There is a symbiotic relationship between black holes and their galaxies that has existed since the dawn of time," Kevin Schawinski, a Yale astronomer said in a June study.