The "largest known structure in the universe is... a big hole"

[SPCTRE]

Guardian: Astronomers discover largest known structure in the universe is ... a big hole

Scientists searching for an explanation for an unusually cool area of sky instead discovered a supervoid: an empty spherical blob 1.8 billion light years across

Astronomers have discovered what they say is the largest known structure in the universe: an incredibly big hole.

The “supervoid”, as it is known, is a spherical blob 1.8 billion light years across that is distinguished by its unusual emptiness.

István Szapudi, who led the work at the University of Hawaii at Manoa, described the object as possibly “the largest individual structure ever identified by humanity”.

(in before "ur mom" jokes)

The so-called Cold Spot was discovered 10 years ago and has proved a sticking point for the best current models for how the universe evolved following the Big Bang. Cosmological theory allows for a bit of patchiness in the background temperature, due to warmer and cooler spots of various sizes emerging in the infant universe, but areas as large and cold as the Cold Spot are unexpected.

The supervoid is not an actual vacuum, as its name suggests, but has about 20% less stuff in it than our part of the universe – or any typical region. “Supervoids are not entirely empty, they’re under-dense,” said András Kovács, a co-author at the Eötvös Loránd University in Budapest.

My favorite part of the article talks about the behavior of photons travelling through the supervoid and how the discovery relates to the concept of a rapidly expanding universe. Fascinating stuff.

The existence of an empty patch helps explain the Cold Spot because assuming the universe is expanding at an accelerating rate, photons of light would be expected to slow down (cool) as they cross a void.

This is because the photons convert kinetic energy to gravitational potential as they travel to the heart of the void and get further from denser surrounding patches of universe – think of it as climbing a hill. In a stationary universe, the situation would be symmetrical and so the photons would regain the lost energy on the way out of the void (down the hill) and exit at the same speed. In an accelerated expansion of the universe, however, everything is effectively becoming less dense as space is stretched out, so voids become relatively shallower over time. This means by the time the light descends the virtual hill, the hill has become flatter and the light cannot pick up all the speed it lost on the way in.

The observation that the Cold Spot and supervoid coincide would fit with the idea that the universe is indeed expanding at an accelerating rate, which scientists put down to forces linked to dark energy. “This is independent evidence, in case anyone doubts it, for the existence of dark energy,” said Frenk.

 

[urbandefault]

Yeah, there's a giant amoeba inside. We've known about this since 1968.

 

[Ithekro]

A lot of amoeba. It keeps dividing into more, but even at low warp speeds it has only managed to fill an area 1.8 billion light years across.

 

[Metryq]

[yt]https://www.youtube.com/watch?v=i8ijbu3bSqI[/yt]​

 

[Santaman]

Tsk tsk, faulty maintenance.. even the universe has a pothole...

 

[Scout101]

It was a rough winter...

 

[publiusr]

At one point a relative to cosmic strings was suspected of being a void--a certain beasty called a texture: http://en.wikipedia.org/wiki/Texture_(cosmology)