sciencetech-blog

comments

A new theory suggests black holes might die by transforming into a 'white hole,' which theoretically behave in the exact opposite manner as a black hole.

Rather than sucking all matter in, a 'white hole' is thought to spew it all out.

The theory is based on the speculative quantum theory of gravity and scientists believe it may help determine the great debate about whether black holes destroy the things they consume.

Black holes: According to a new theory, a 'white hole' would explosively expel all the material consumed by a black hole

According to the theory, a 'white hole' would explosively expel all the material consumed by a black hole.

Researchers suggest 'that the transition from black hole to white hole would take place right after the initial formation of the black hole, but because gravity dilates time, outside observers would see the black hole lasting billions or trillions of years or more, depending on its size.'

If the authors are correct, tiny black holes that formed during the very early history of the Universe would now be ready to 'pop off like firecrackers' and might be detected as high-energy cosmic rays or other radiation.

According to Albert Einstein's theory of relativity, when a dying star collapses it will often come to a point where the collapse is irreversible - at which point, it becomes a black hole, sucking in light and anything else in its cosmic vicinity.

It's long been suspected that gigantic black holes lurking in the heart of galaxies rotate faster and grow larger as they feast on gas, dust, stars and matter. But there hasn't been a reliable measurement of the spin rate of a black hole until last year.

While black holes are difficult to detect, the region around them gives off telltale X-rays.

Oposite: While a black hole sucks matter in, a white hole expels matter at an explosive rate

Using Nasa's newly launched NuStar telescope and the European Space Agency's workhorse XMM-Newton, an international team observed high-energy X-rays released by a supermassive black hole in the middle of a nearby galaxy.

They calculated its spin at close to the speed of light — 670 million mph.

It was the first 'unambiguous measurement of the spin rate' of a supermassive black hole, University of Maryland astronomer Christopher Reynolds, who had no role in the research, wrote in an accompanying editorial.

Behemoth black holes - with masses millions to billions times that of the sun - are thought to reside in every galactic center. They're extremely dense and possess such powerful gravitational tug that not even light can escape.

Light years: The closest black hole to earth is about 26,000 light years away

Scientists are able to pinpoint these monstrous objects from the streams of X-rays emitted during a feeding frenzy. Knowing how fast - or slow - supermassive black holes swirl can help shed light on their growth.

For several days in 2012, the two telescopes simultaneously tracked an immense black hole in a spiral galaxy called NGC 1365. The galaxy was chosen because it was 60 million light years away - relatively close by astronomical standards.

The results were published in an issue of the journal Nature.

So how fast is the black hole at the center of our Milky Way spinning?

It's tough to know because our galaxy's super-massive black hole isn't as active as the observed one, said lead researcher Guido Risaliti of Italy's Arcetri Astrophysical Observatory.

Relativity: Albert Eisntein's theory of relativity outlines what creates black holes throughout the universe

Aside from occasional flares, hardly any radiation flows from our black hole, making it difficult to calculate its spin, Risaliti said.

Maryland's Reynolds said it's clear that some supermassive black holes rotate very rapidly and there's a need for more powerful X-ray space telescopes.

'We are learning about some of the most exotic and powerful objects in the universe,' he said in an email. 'This is cool science.'

The findings are reported in the journal Nature.com,