Some physicists say that it is not possible, while others state that reality cannot exist without this idea. What I am talking about is the theory that we live in a multiverse.
I have talked about this idea a few different times, check out one of my other posts if you are interested. This article that I found is awesome and is basically a cover all for many of the ideas that go along with this theory. What is also nice is that there are plenty of videos to go along with the article which are nice when dealing with such an abstract topic. I use the word “abstract,” but that is basically an oxymoron, because we are talking about the most basic principles of existence, reality, which is anything but abstract yet we still with all our technology do not know what it is or how to explain it. Anyways moving on…
In this article from space.com, which is an awesome website, they discuss this idea with many of the world’s most prominent physicists. I do not mind articles going into detail, and with ideas like this there is way too much information to even begin to wrap your mind around these ideas. The article in my opinion is just a tad too long, and covers so much information that it is almost impossible to digest it all, but do not fret. I have read, well most of it, and regardless of the length there is still some very fascinating information that is presented.
The article focuses on the multiverse theory, obviously, but I say that because I think I was getting the multiverse theory and the many worlds interpretation (MWI) confused. I kind of thought they were the same, they are not, but but I think there is some area where they overlap with one another, we will get to that later though.
One idea that is talked about quite a bit is this idea of “pocket universes” that are within our own universe. Meaning that our universe, or any one for that matter, are so vast that there is an idea that because of the size of our universe the laws of physics can differ from pocket to pocket. That may not seem like a big deal, but if this is the case it makes things much more complicated for us for a variety of reasons. The main reason is that it will be almost impossible to create a theory of everything (TOE) as Stephen Hawking and so many other physicists want to create. Let’s just say for the sake of argument that there are 10 pocket universes in our own universe. That means that there are 10 different laws that govern these pockets, so in theory we will need 10 different theories to describe them. This is a headache as you can imagine. What else could be a problem, and something that may not get brought up, is that if we do somehow figure out interstellar travel, if we were to cross from one pocket to another. First, I am not sure if this will be possible, but I cannot see how it would be impossible, but if we did travel from one pocket to the other then maybe our ship would not work in this other pocket because gravity is different or any number of physical differences that could affect the ship. So this could be another element of danger when it comes to interstellar travel.
During much of the article most of the experts believe that even though there could be infinite or near infinite universes (we will get to that in a second) that most of these universes will be sterile. Meaning there will be no life and no chance that life could form because of the drastically different physical laws that govern these universes. We are extremely lucky that conditions were just right for us to have come along. However, there is a very slim margin for error, and when you look at the odds they are more in favor of a universe not having life. But again given enough chances, even things with extremely low probabilities will be possible, and look here we are.
So now looking at the numbers. From the article: “our pocket universe may be at least 10^23 times larger than our observable universe (because, in order to work, inflation requires at least 100 doublings of the size of the universe, 2^100 = roughly 10^30). This means that the pocket universe we call home would be 100 billion trillion times larger than everything we can see with our largest telescopes. (Models, no surprise, do jump around.)”
Yeah I mean that is astronomical to think about, basically unfathomable in every sense of the word. What is insane to think about beyond this idea is that there are an infinite or near infinite number of universes. I am not talking about pocket universes because from what I understand they are contained in one universe. So any universe can have multiple or perhaps near infinite pocket universes, while there still being a near infinite number of universes. Which if this is truly the case, I would think that nothing is impossible, and that word has no meaning. The article states that:
“To be clear, a truly infinite universe means that anything that is not impossible (no matter how obscure) will happen, must happen and must happen, weirdly, an infinite number of times.”
So if this is true then something that has even the smallest possible chance of happening, a one with a million 0’s in front of it will happen, and will happen an infinite number of times. So following that logic, how will it have such a low probability of happening if it does so infinitely? BOOM, that was my brain exploding out of my head. The article and myself both think this is strange if it is true. To me I cannot fathom something being “impossible,” following this mindset or logically thinking about what is in front of me. I am a firm believer that life and reality is probabilistic, and science has mostly proved that, but even something that has almost no chance of happening will happen, and it will happen infinitely in the multiverse.
Similarly, as long as there is sufficient space for unending random shufflings of particles (and a universe of infinite size certainly has sufficient space), there would have to be a sector of space out there identical to our sector of space, with persons identical to you and to me. Tegmark estimates that our closest identical copy is 10^10^28 m away.
This statement is rather strange and almost disturbing if true, and again will make your head explode if you think about it too much. I would love to have some answeres about one of the most basic traits that humans experience, but the reality of the situation (pun intended) is that, the more layers we peal back, the more questions that arise. I dare say that despite our advancement in a variety of areas including physics and cosmology, we are no closer to figuring out our reality. The rabbit hole goes much deeper than we imagined…