Most of us know that we live in the Universe. But how correct is it to say that? Do we really live in the Universe. Is our Universe the only one or are there others out there? This idea is not a new one. If one is told that we live inside a Universe then he or she is bound to ask what is outside it? And as in many cases, we still do not know. But how is that going to stop scientists from speculating?
As you might have already guessed, there are various theories regarding this, from our Universe being one of many, to all of this being a simulation inside a giant computer!! We won’t discuss all of these “wild” theories but the former of the above mentioned is worth discussing as it may actually have evidence to support it.
The CMB Cold Spot
This is a picture of the baby Universe and the portion encircled is the “evidence” I mentioned earlier. But before we go into that, let us first understand what we are looking at.
The Cosmic Microwave Background, which is what the image is called is the radiation leftover from the Big Bang itself. This radiation tells us what the early Universe was like. And by early, I mean just 300 million years after the Big Bang. To put that into perspective, the Universe currently 13.8 billion years old.
Although not an exact “picture” each colour in the picture represents the temperature fluctuations in during the early years after the Big Bang. The variations in temperature are only about 1 or 2 degrees. That might not sound very high but it was these minor differences that made stars and galaxies as we see them today, however that is another story.
Keeping that in mind let us return to the encircled region. That region is way colder than its surrounding. This should not be the case according to modern theories. Scientists don’t know why but it might be evidence to something incredible. This area is called the CMB Cold Spot or sometimes the Eradinus Supervoid.
A Supervoid or something else…?
Today, our Universe looks something like this. This is just an artist’s rendition but the pink filaments and yellow knots we see in the picture are actually galaxies and clusters. On the largest scale our Universe is arranged like a thick cobweb with filaments of galaxies surrounding huge areas with pure nothingness.
These are called voids. The Cold Spot is thought to be one such area, only much larger. In other words it’s a supervoid. Its just a huge, empty hole with no stars and no galaxies, which might explain the drop in temperature. However recent theories suggest that this might not be the only explanation behind it.
According to late scientist Stephen Hawking, this area might be the evidence of a collision with another Universe!! This means that our Universe can be considered as a bubble floating in a much larger Multiverse along with many other Universes. In such a scenario we could expect many Universe merging, colliding or just doing nothing.
If so what we are seeing might be a mark or bruise on our Universe that appeared as it collided with another Universe. But this is just a theory. We are not sure whether this is the case.
However the great thing about this is that it is actually verifiable. If another Universe has indeed crashed into our own, we must see an identical cold spot on the exact opposite side of the visible one as shock waves after the collision would converge on the other side. Although we haven’t seen any other spot like this yet, the search is still own, with more advancements in radio and microwave astronomy.
But if it is true, then humanity would have stumbled upon a big hint to the nature of reality and our place in the cosmos, or should I say, the place of our Cosmos. This could lead to a whole new level of physics. Who knows whether the laws of science hold in the Multiverse as they do here? How would the other Universes look like? Is there life in any of them?
And if humanity survives till the end of our Universe, we might even escape to the Multiverse when our Universe dies. The scale of reality itself would increase tremendously and we would be way closer than we currently are to a Theory of Everything that would answer all questions that man ever wondered about.