The largest structure in the universe might be a big patch of nothing

[Reefa]

A team of astronomers from Institute for Astronomy at the University of Hawaii at Manoa have been examining data collected by the Planck Satellite a decade ago, and have come to an interesting conclusion: We might have found the single largest structure ever in the universe, and the only sign of it is nothing – just empty space 1.8 billion light years across. That’s 18,000 times larger than our entire galaxy.

This gaping hole in space was first spotted as an unusual artifact in a scan of the cosmic microwave background radiation from 2004. In this detailed scan of the sky, there was a large area of very low background, the so-called “Cold Spot” (toward the bottom right in the picture above). The standard model of cosmology predicts that there would be warm and cold spots in the background radiation of the universe. But the existence of such a large gap could indicate that we’re missing a piece of the puzzle, or that there’s something very, very large between us and this section of sky.

István Szapudi, who led the work at the University of Hawaii, says the newly acquired data indicates the Cold Spot is indeed caused by an area of the universe with a very low density of matter. There should be about 10,000 more galaxies visible in this region, which is about 3 billion light years away. This structure, temporarily known as the “supervoid,” isn’t technically empty. It has about 20% of the amount of matter you’d expect, which in the cosmological sense is very unusual. Astronomers expect only a handful of voids this size to exist in the entire universe, and this one is (relatively) close to us.

The team came to the conclusion that there really is a big, mostly empty void in space by combining data from Hawaii’s Pan-STARRS1 (PS1) telescope and NASA’s Wide Field Survey Explorer (WISE) satellite. PS1 contributed optical wavelength data and WISE scanned the infrared. So what about the Cold Spot? The researchers believe that’s explained by the way light passes through the supervoid.

Imagine a photon enters the void. As it moves farther away from the denser surrounding universe, it converts kinetic energy into gravitational potential — it loses energy like a car coasting up a hill. (Light doesn’t slow down, of course, but it can change wavelength.) When it comes “down” on the other side and leaves the void, you might think it would gain that energy back, but there’s that pesky expanding-universe thing. In the eons it takes light to pass through the supervoid, the universe has expanded and become even less dense, meaning photons gain back less energy after coming down the virtual hill.

It’s also possible we’re just seeing the first hints of an exotic new kind of physics that hasn’t been fully integrated with the standard model. This may also be more evidence for dark energy. But there’s a lot of nothing still to study.

http://www.extremetech.com/extreme/203998-the-largest-structure-in-the-universe-might-be-a-big-patch-of-nothing

[Fallon]

Dark Energy is thrown in anytime some interest has to be aroused. But it's not necessary here, because there is a wild explanation for the Cold Spot.

Our universe is likely to be one of many. The Cold Spot could exist because of the pull of another universe in the next room of the multiverse hotel.

Evidence of the existence of 'multiverse' revealed for the first time by cosmic map

By Rosie Taylor for the Daily Mail

The map shows radiation from the Big Bang 13.8billion years ago that is still detectable in the universe - known as cosmic microwave radiation.
Scientists had predicted that it should be evenly distributed, but the map shows a stronger concentration in the south half of the sky and a 'cold spot' that cannot be explained by current understanding of physics.

Laura Mersini-Houghton, theoretical physicist at the University of North Carolina at Chapel Hill, and Richard Holman, professor at Carnegie Mellon University, predicted that anomalies in radiation existed and were caused by the pull from other universes in 2005.
Now that she has studied the Planck data, Dr Mersini-Houghton believes her hypothesis has been proven.
Her findings imply there could be an infinite number of universes outside of our own.
She said: 'These anomalies were caused by other universes pulling on our universe as it formed during the Big Bang.

'They are the first hard evidence for the existence of other universes that we have seen.'