Is the "Great Void" One-Billion Light Years Across the Imprint of Another Universe or a Statistical Error?
In 2004 astronomers found an enormous hole in the southern hemisphere of the Universe, nearly a billion light-years across, empty of both normal matter such as stars, galaxies, and gas, and the mysterious, unseen "dark matter." This was a startling finding, since accepted models of the early universe say that the big bang created an initially uniform cosmic landscape, when viewed on large scales. While earlier studies have shown holes, or voids, in the large-scale structure of the Universe, this discovery dwarfed them all. This "nothing" is an enormous hole in the cosmos that defies standard cosmology and might just be the imprint of another universe bumping against our own while some astronomers suggested the spot could be a supervoid, a remnant of an early phase transition in the universe.
This giant cold spot has a cosmic microwave background a chilly 20 to 45 per cent lower than the average for the rest of the sky, according to NASA's WMAP satellite.
Smitten, astronomer Lawrence Rudnick decided to take a closer look in 2007 by examining a survey done by the Very Large Array radio telescope in Socorro, New Mexico. His team announced that the most likely cause of the cold spot was a giant void nearly 1 billion light years across that contained almost no stars, galaxies or dark matter.
"We already knew there was something different about this spot in the sky," said Lawrence Rudnick of the University of Minnesota. The region had been dubbed the "WMAP Cold Spot," because it stood out in a map of the Cosmic Microwave Background (CMB) radiation made by the Wilkinson Microwave Anisotopy Probe (WMAP) satellite, launched by NASA in 2001.
Meanwhile, Laura Mersini-Houghton of the University of North Carolina theorizes is that it could be the imprint of another universe beyond our own, caused by quantum entanglement between universes before they were separated by cosmic inflation. Laura Mersini-Houghton said, "Standard cosmology cannot explain such a giant cosmic hole" and made the remarkable hypothesis that the WMAP cold spot is "… the unmistakable imprint of another universe beyond the edge of our own."
String theory says that ours is just one of 10500 possible universes, and Mersini-Houghton's calculations suggest that this giant void could have been caused by a neighboring universe pushing against our own, repelling gravity and the galaxies contained within.
If true this provides the first empirical evidence for a parallel universe. It would also support recent developments in String theory.
The Mersini-Houghton team claims there are testable consequences for its theory. If the parallel universe theory is true there will be a similar void in the northern hemisphere of the Celestial sphere. Mersini-Houghton has worked on a variety of topics on the particle physics-cosmology interface. She is particularly interested in the possibility of generating dark energy from transplanckian physics in string theory, gravity and quantum field theory in curved space, and higher-dimension braneworlds.
Earlier this year, 2009, Dragan Huterer of the University of Michigan and colleague Ray Zhang threw cold water on these theories, arguing that the spot is no more than a byproduct of the statistical tool commonly used to examine CMB data, called—the Spherical Mexican Hat Wavelets method. Really!
Huterer and Zhang analyzed the cold spot using two simpler statistical tools, finding that the cold spot's temperature deviation from the CMB average is, after all, no more or less than anywhere else in the universe.
Hunter and Zhang not withstanding, there seems to be more cold spots that hot spots on the cosmic background radiation map, with the distribution skewed toward the cold end, suggesting there's something wrong with current inflationary theory, The slight variations in cosmic background radiation are thought to be the outcopme of quantum flucuations that resulted in greater and lesser accumulations of matter. The slightly colder pateches reflect the places were matter has scattered the radiation. But the amount of matter taht can be deduced from the COBE and WMAP maps suggest that there wasn't enough ordinary matter to form the galaxies we now see. The missing attarction is presumed to be from dark matter. As yet there's a 99 percent probability of the numbers being correct, where scientists like to see something closer to 99.9999 percent to declare the data safe.
The CMB, faint radio waves that are the remnant radiation from the Big Bang, is the earliest "baby picture" available of the Universe. Irregularities in the CMB show structures that existed only a few hundred thousand years after the Big Bang.