The MultiVerse Simply Explained - Part 1 of 5 (Or How To Bake Your Noodle In A Few Easy Steps)

The Multiverse is an hypothesis that there are more universes than the one that we can currently observe with our eyes and various scientific instruments. There are actually multiple versions of this hypothesis which is quite ironic. Each version is fairly complicated in and of itself so I am going to present them in a series of posts.

In this post the "conventional" multiverse hypothesis will be presented in the simplest manner possible.

_{The Evolution of the Universe

(image credit: Wikimedia Commons)}

The Conventional Multiverse

In this version it is proposed that the current universe we reside in is much vaster than we can observe. Much, much vaster. We can currently look back in time about 13 billion years to the microwave background and it is estimated that the observable universe is about 90 billion light years in diameter.

We also know that the farther an object is from us here on Earth the faster it is retreating from us due to the expansion of the universe. It is postulated that this speed keeps increasing up to and past the speed of light (see note 1). Any object that is farther away than that has no chance of being observed by us because light emitted from it has no chance of overtaking the expansion of the universe. It is effectively isolated from us for all time and can be thought of as being in a separate universe.

So this region of space is technically connected to our region of space in the conventional sense but it just cannot communicate with us or be seen by us. It also goes the other way around: any light emitted from Earth will never be able to reach that region of space due to the expansion effect of the universe.

_{A representation of a Hubble Volume

(Image credit: Wikimedia Commons)}

Hubble Volumes

Now comes the part that will cook your noodle.

A Hubble volume is a (probably) spherical region of the observable universe surrounding an observer beyond which objects recede from that observer at a rate greater than the speed of light due to the expansion of the Universe. This is what I already described in the previous section.

So our region of the universe, the observable universe is a Hubble volume.

If the universe is vastly larger than, or even infinitely than, our Hubble volume then it is essentially guaranteed that the arrangement of matter and energy that comprises our local region of space, the Earth or the solar system or even our Milky Way Galaxy will be replicated somewhere else. The odds are very low but in an infinite universe it has to happen.

Therefore there will be an identical or near identical version of you out there somewhere. Of course we will never know it because there is no way of communicating with this region of space.

I will go on about other, even weirder, versions of the multiverse in a later post.

Note 1: Note that this does not violate the speed of light postulate in Special Relativity because it is the volume of space that is expanding faster than the speed of light. No matter or even signals are moving faster than the speed of light in that local volume.

The MultiVerse Simply Explained - Part 1 of 5 (Or How To Bake Your Noodle In A Few Easy Steps)

The Conventional Multiverse

Hubble Volumes

Further Reading