Scientists have been eager to determine the answer to the dilemma – does the recently found mysterious and dark area in the cosmic microwave background, called “cold spot” -the radiation leftover from the big bang, can actually be a parallel universe?
The “cold spot” was initially noticed in 2015 and is a 1.8 billion light-year vast region where there are actually an estimated 10,000 galaxies ‘missing’. The puzzling region consists of 20 percent less matter than it should, based on the Standard Model, which left researchers confused.
Scientists had speculated that there are billions of other universes, lurking outside the one that we can see, and had been baffled by the possibility that this void can be made by a collision between two different universes and this void can actually prove this theory.
According to the recent research, led by postgraduate student Ruari Mackenzie and Professor Tom Shanks in Durham University’s Centre for Extragalactic Astronomy, published in Monthly Notices of the Royal Astronomical Society:
“The voids we have detected cannot explain the “Cold Spot” under standard cosmology. There is the possibility that some non-standard model could be proposed to link the two in the future but our data place powerful constraints on any attempt to do that.” – Mackenzie commented.
Figure 1. The map of the cosmic microwave background (CMB) sky produced by the Planck satellite. Red represents slightly warmer regions and blue slightly cooler regions. The Cold Spot is shown in the inset, with coordinates on the x- and Y-axes, and the temperature difference in millionths of a degree in the scale at the bottom. Credit: ESA and Durham University.
By using a spectrograph deployed on the Anglo-Australian Telescope, Mackenzie and Shanks made use of an effect known as a cosmological redshift to measure the colors of the galaxies, their redshifts, and therefore their distances can be calculated. The results of this comprehensive study of the redshifts of 7,000 galaxies show no proof of a supervoid suitable to explain the “Cold Spot” within the standard theory.
Figure 2. The 3-D galaxy distribution in the foreground of the CMB Cold Spot, where each point is a galaxy. The galaxy distribution in the Cold Spot (black points, at right) is compared to the same in an area with no background Cold Spot (red points, at left). The number and size of low galaxy density regions in both areas are similar, making it hard to explain the existence of the CMB Cold Spot by the presence of “voids”. Credit: Durham University.
According to this survey, Durham University found that the void is actually made up of many tiny voids which were a too small shift light, as illustrated in Figure 2.
“This means we can’t entirely rule out that the Spot is caused by an unlikely fluctuation explained by the standard model. But if that isn’t the answer, then there are more exotic explanations. Perhaps the most exciting of these is that the Cold Spot was caused by a collision between our universe and another bubble universe. If further, more detailed, analysis of CMB data proves this to be the case then the Cold Spot might be taken as the first evidence for the multiverse– and billions of other universes may exist like our own.” – Shanks commented.
Although many of the explanations out there seem unlikely, we don’t necessarily have to dismiss them as pure fantasy. Scientists at the moment are planning to perform an additional examination of the CMB, to check if the concept of parallel universes withstands.