Science won't suffice 🧪🔭

What if one day you wake up in the most normal way but as the day goes on, you realise that all the people around feel completely different even though you see them everyday?

Meaning, you are with similar faces and surroundings but actually in a completely different place (or different world might I add).

This may seem like a plot of a science fiction movie, but the co-existence of worlds like our own is not entirely impossible according to some physicists. And some believe that communication and transportation are possible as well. 

Sci-fi fans must be aware of terms such as, parallel worlds, parallel universes (multiverse), etc., that are widely used to describe the theories of different worlds like our own. 

How did this idea of many-worlds come to be researched?

Although these ideas have been around from ancient times, Hugh Everett III (American physicist) in 1957 started the idea of parallel universes with research in mind. 

Now, let us look at the various theories that may have been created all the worlds:

ETERNAL INFLATION

Around 13.7 billion years ago, everything burst into action and spread throughout, inflating faster than the speed of light. In a fraction of a second, the universe had exploded into a huge never-ending-like space. This process of inflation and explosion is called the cosmic inflation. 

After that, as inflation slowed, a radiation appeared, creating the Big Bang fireball, and began to form atoms, molecules, stars and galaxies that now surround us. 

That mysterious process of inflation and the Big Bang might have happened somewhere else too, making it convincible that multiple universes are possible.

Also, according to physicist Alexander Vilenkin, inflation didn't end everywhere at the same time. While it ended for Earth, another Earth-like place may have come into existence 100 or 1000 years later. In fact, cosmic inflation continues in one place or the other. This is called the theory of eternal inflation. 

BUBBLE UNIVERSE THEORY

When the Big Bang happened, some parts of space-time expanded faster than others. This created 'bubbles' of space-time with each bubble containing its own universe. As inflation ends in one place it starts in another, forming a new bubble universe.

MANY-WORLDS INTERPRETATION (MWI)

This theory implies that there are infinitely uncountable universes. It is a hypotheses in physics that views every possible outcome of a quantum event to exist in its own universe. The "Schrödinger's cat" paradox by Erwin Schrödinger states that if a cat is placed in a sealed box with a flask of poison and radioactive source, the cat may be both dead and alive simultaneously in two different worlds but a person may experience only one of its outcomes. 

THE BIG BANG

Universe began at Big Bang as most scientists believe, but on the opposite side of the timeline, back in time, another universe exists which is a complete mirror image of our own. In other words, both universes were created at Big Bang, but one exploded backward in time while the other, forward in time. 

These theories support the ideas of multiverse but there are also things that shatters the ideas of multiverses. These include:

• Falsifiability - Since all are just theories about multiverse without actual witnesses, these theories may be proven wrong. 

• No evidence - There is evidence amounting to none about the theories of multiverses. 

Not all physicists believe multiverse exists and even fewer believe it possible to contact these universes. 

But still some scientists have made different classifications of the universes that may exist. 

Tegmark's classifications

In 2003, MIT physicist Max Tegmark broke down the different types of parallel universes allowed by physics into four levels:

• Level 1 - Regions Beyond Cosmic Horizon

• Level 2 - Other post-inflation bubbles

• Level 3 - The Many Worlds of Quantum Physics 

• Level 4 - Other Mathematical Structures 

Greene's classifications

In his 2011 book, Brian Greene approached another system of classification of parallel universes: 

• Quilted Multiverses

• Inflationary Multiverse

• Brane Multiverse

• Cycling Multiverse

• Landscape Multiverse

• Quantum Multiverse 

• Holographic Multiverse 

• Simulated Multiverse 

• Ultimate Multiverse 

So if you somehow transport to another world or universe, you may be able to know how your life would look like if you took a different decision in one point of your life.

By-Laboni Ayanna Duarah