I answered a question hundreds of episodes ago: "What will the universe expand into?" The answer at the time was mainly that, as far as we understand it, the universe has not really expanded into anything.
If you walk in either direction long enough, you'll be back where you started. And because the universe is expanding, the journey takes longer, but the universe hasn't changed into anything yet.
So, I'm going to put an asterisk on the answer and then when you read this article you'll see "unless we live in a multiverse".
There's a super interesting and absolutely viable idea: we're actually in one universe in a giant multiverse. Each universe is a bit like a soap bubble, embedded in the cosmic vacuum of the multiverse, expanding from its own Big Bang.
Our universe could actually be part of a larger multiverse. Photo: Jim Misty (Mount Misty Observatory)
Every universe has completely different laws of physics. In fact, there are many physical constants in the universe, such as gravity and the binding strength of atoms. These fundamental constants, like the result of random dice rolls by the laws of physics, have given rise to our universe—a place that is almost hostile to life but not entirely hostile.
Imagine that all these different cosmic bubbles appear in this giant cosmic bubble of the multiverse, with different physical laws. Maybe in another universe, gravity is obnoxious, it could be green, or it could produce unicorns.
There is no life in most of the universe, but if you roll the dice countless times, you will eventually reach the conditions for life.
Any life form that can perceive the universe must evolve to a universe that can survive.
Sure, it sounds like pseudoscience gibberish, and next you think I'll talk about chakras, astrology, or channeling with Bigfoot.
Wait, it could be really science. If these bubble universes are close enough, they may rub together in some way, and this friction can be detected from within the universe.
In other words, we can look into space, see the scratches of the universe, and know that's where our universe collides with another universe.
So, have astronomers looked at space for signs of interaction between our universe and other universes? They did find some very strange phenomena.
Cosmic microwave background radiation (enhanced to show anomalies). Source: ESA and Planck
While studying the cosmic microwave background radiation (residual radiation after the Big Bang), astronomers discovered a temperature fluctuation. These different temperatures, or anisotropy, were regions of varying densities of matter in the early universe that were amplified on a massive scale as they continued to expand.
While many of these temperature differences can be explained by current cosmic theories, there is one place that contradicts them. This is so strange. The researchers who found it named it "Axis of Evil," in the words of one president.
Speaking of which, there are many thoughts about the axis of evil. Seriously, all of these ideas are more plausible and likely than I would say.
But there's a very fascinating idea that we're seeing one region where our universe is colliding with another, and that contact violates each other's laws of physics.
If that's the case, what does that astronomer being witnessing interactions between the universes mean for those poor aliens who might be covered by another universe?
We don't know, but imagine what happens when the physical laws of two completely different universes overlap. What is the average of 7 and green? What about the average of 26 and unicorn dreams? Whatever it is, it's not good for aliens and their continued healthy survival.
But don't worry, that region is billions of light-years away, and it might not be another universe, we just need better observations.
We covered this topic in detail in Episode 408, The Astronomical Cast, so if you'd like to hear more from Dr. Pamela Guy, watch the episode. You should especially like watching me break my head for this brain-burning problem and then put my head back together and wrap it up.
BY: universetoday
FY: Colleen
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