Looking into a parallel universe,
watching images like myself do
what I do on a daily basis.
Sad to know that there’s another
self going through the same trials,
sufferings, loneliness, emptiness,
abandonment and pain as I myself
go through every day.
Maybe we can meet someday and change
both our patterns of living, as we
enter realms of heaven together.
RoseAnn V. Shawiak
Parallel universes. Whether you are a physicist, a sci-fi fanatic, or a movie lover, you have probably encountered some idea of the existence of parallel worlds. Some believe that an alternate universe is just like our own, but with some subtle differences. Others believe that it is a completely opposite world. Now we could go into all the confusing details about quantum mechanics and string theory, but let’s take it back to the basics. What might other worlds be like, how do they exist? There are many, many theories, so let’s explore just a few.
The level one theory of a parallel universe is that if you go far enough, you will eventually get back home. Based on the rules of probability, in an infinite universe, somewhere out there are planets exactly like Earth, and events on such planets would be virtually identical to those on our own planet. This theory depends on two assumptions. The first is that the universe is indeed infinite, which we have no way of proving. The other is that every single possible configuration of particles in our own Hubble volume occurs several times. Since we cannot see farther than 14 billion lightyears away, communicating with or going to our “sister” planets is virtually impossible.
The level two theory has to do with the continuing inflationary phase that all universes are in. It basically states that if you go far enough, you’ll end up in wonderland. The idea is that when the Big Bang occurred, many bubble universes were created, not just ours. These universes then started to grow or inflate, all of them at different rates. The ekpyrotic model of this theory states that if two expanding branes collide, they can collide at multiple points, like flapping a sheet up and down on a bed. Each point of collision then creates its own universe with its own separate initial conditions. This theory means that creation is inflating at an increasing rate over time.
The level three theory comes from the many worlds interpretation of quantum physics. It basically states that with every choice we are represented with, every single possible outcome happens on a different plane. In this idea, every decision you face splits your “self” into infinitely many universes. Level three parallel universes occur in the same time and space as the one we reside in, but we still have no way of accessing them. This theory has the least to do with string theory directly, but it originated from the famous Schrödinger’s Cat experiment, which developed the idea of superposition.
The level four theory is perhaps the strangest and most controversial of all. It is based on the mathematical democracy principle, which states that any universe that is mathematically possible has an equal possibility of existing. In a nutshell, any universe that can be worked out on paper exists. These worlds would have fundamentally different laws of nature from our world.
The Multiverse theory is a more recent theory. It describes the continuous formation of universes through the collapse of giant stars and the formation of black holes. With each of these black holes there is a new point of singularity and a new possible universe. Each universe starts with its own “Big Bang”, and from there it traces out its own distinctive cycle. This theory has many implications. Most notable is the unique, complex process from which our own universe was born, and how easily it could have been different. It may imply that, out of the possibly thousands, millions, or billions of universes, ours was special enough to develop life, which is a truly humbling concept.
Of all of the theories that exist, nearly all parallel universe theories agree that travel to or even communication with other universes is virtually if not completely impossible. However, science makes progress every day. Maybe someday, someone will make a great leap and figure out how to connect us with other planes of existence.