WHATEVER YOUR RELIGIOUS BELIEFS ARE I SUGGEST YOU WATCH THIS REGARDLESS WITH AN OPEN MIND. THIS IS NOT MEANT TO ENTICE RELIGIOUS DEBATE, BUT PURELY FROM A SCIENCE POINT OF FEW
It' deals with parallel dimensions and the concept of multiple universes and soap bubble universes.
http://tvshack.net/tv/The_Universe/season_3/episode_2/
Some of the world's leading physicists believe they have found startling new evidence showing the existence of universes other than our own. One possibility is that the universe is so vast that an exact replica of our Solar System, our planet and ourselves exists many times over. These Doppelganger Universes exist within our own Universe; in what scientist now call "The Multiverse." Today, trailblazing experiments by state of the art particle colliders are looking for evidence of higher dimensions and Parallel Universes. If proof is found, it will change our lives, our minds, our planet, our science and our universe.
In short, I will try to explain the best that I can, but I will fail since this is so complex. Basically there are 4 different types of parallel universes (universes inside universes in different dimensions) Level 1, Level 2, Level 3, and Level 4.
Basically from what I understand is that Level 2 universes are different copies of universes that have broken off into their own universe. Imagine that you are a on boat, the ocean is your dimension, you don't know that under the ocean there is life (fish/etc.) unless you go into that dimension (go under water) so two universes exist within each separated by mere millimeters.
Level 3 parallel universes is basically a copy of our own universe in the same space that we occupy ourselves. Meaning that there is another parallel universe right where were standing, and similar to the butterfly effect where tiny changes in nature (a butterflies wings) causes a hurricane, tiny changes causes complete different outcomes.
What this basically means is that shown by the laws of quantum physics it says that an sub-atomic particle should be in two places at once or in different dimensions at different time what this means is that every decision that is made all the other known possibilities of it are made as well. What this holds is that there are dimensions where some wars never happened or ended different, or some wars that never began in our history actually did, and were some species never went extinct. Meaning yes in a parallel universe dinosaurs still exist
I know this sounds crazy, but like I said the laws of psychics testify to this happening on the sub-atomic level and thus ability to happen in large ramifications (copies of universes)
So the biggest thing you have to grasp from this is, as you sit in front your computer another human or animal or anything could be moving in the same space as your house or living room and the fact is you don't notice one another because they are in different dimensions. (This is where string theory and subsquent "M" Theory come into play where your dimension is located on a membrane and the other dimension is located on another membrane than are tethered together by things we do not yet understand) see picture below
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"Bubble universes", every disk is a bubble universe (Universe 1 to Universe 6 are different bubbles, they have physical constants that are different from our universe), our universe is just one of the bubbles.
Definition of M-theory: In M-theory our universe and others are created by collisions between p-branes in a space with 11 and 26 dimensions (the number of dimensions depends on the chirality of the observer) each universe takes the form of a D-brane. Objects in each universe are essentially confined to the D-brane of their universe, but may be able to interact with other universes via gravity, a force which is not restricted to D-branes[16]. This is unlike the universes in the "quantum multiverse", but both concepts can operate at the same time.
M-Theory deals with multiple universes not parallel universes, but multiple universes, what it says is there are membranes called "p-branes" that are in hyperspace or the bulk which is the space of all space. Imagine like a sticky paper these membranes (which have universes on them) if you will that flap very close to one another when they collide another universe is created and it is called a "d-brane", but while everything that is inside that universe cannot get out, universes can interact via gravity because that is a force not restricted to d-branes.
What is fascinating is that there are infinite copies of yourself in different parallel universes because EVERYTHING is copied. And the laws of psychics say that for example a cat that is alive in 20 different parallel universes can be dead in 4 other parallel universes.
Level 4 parallel universe is a universe where the actual laws of psychics are changed or may not apply, meaning there could be another copy of our universe where instead gravity didn't exist so all it is just a bunch of gases mixed.
It is very radical stuff and the foundation of proving it is the particle accelerators you hear about in the news, what they try to is make two protons (one proton one anti-matter proton) smash into each other at speeds near the speed of light and then by reassembling the smash see if there are gravitons (particles that carry gravity) that are missing that were smashed into a different dimension. And it could take years and billions upon billions of collisions until one unique occurs where some gravitons are passed into another dimension.
So now all we have to do is wait until that has happened and there will be definitive proof (beyond what we have with the laws of psychics or quantum psychics or general relativity and what we see happen on an atomic level and beyond "theoretical calculations). This is where the particle accelerators fit in and the graviton as you learned in M-theory are not limited to one universe or d-brane and can interact with parallel universes as well as other universes.
sources: wikipedia
history channel