Do Parallel Universes Exist?

Could we be living in one of many parallel universes? Find out why some physicists think we might.

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Host, Producer: Greg Kestin
Researchers: Samia Bouzid, Drew Gannon, Peter Chang
Writers: Samia Bouzid, Greg Kestin
Fish voices: Tiffany Dill, Arlo Perez
Scientific Consultant: Alan Lightman, Curtis McCully
Editorial Input from: Julia Cort, Ari Daniel
Filming: Greg Kestin
Animation and Editing: Greg Kestin
Special thanks: Entire NOVA team
From the producers of PBS NOVA © WGBH Educational Foundation
Funding provided by FQXi
Music provided by APM

[novapbs]

The idea of parallel universes is so fascinating! Also, cool fish!

[WhatThePhysics]

The multiverse is a perspective that's growing in popularity in the community of physicists. The multiverse, at first, does seem pretty crazy, but at one point, so did the idea that there were other solar systems.

[BigNewGames]

@0:48 The lambda is not constant! There is not a constant rate of dark energy expansion, i.e., the Hubble constant is not really constant. Just like gravity does not effect space at a constant rate everywhere but is dependent on the amount of mass contained within space. Same thing goes for the expansion of the universe.

Mass not only causes gravity locally but mass also produces energy locally (weak nuclear force). This new energy entering space locally around mass can explain dark matter, the movement of stars and galaxies and is also able to explain the exponential expansion of space that occurs with great distance. Expansion of space occurs because when energy is added to space it adds volume to the universe, i.e., the distance between mass. It is not until this energy (dark) is added up over great distances does the expansion of space become apparent.

[harikrishna]

You made it simple for common people to understand. That is real genius

[mrneonsplat]

I have a theory. Since there are supposedly infinite universes. Who is to say every time we sleep and dream, we go to another universe? 99% of the time everything is exactly the same with the exception Maybe only 1 change maybe someone owns a different shirt or one leaf on a tree fell differently or an infinite number of minor things. But sometimes there is a major change that challenges your own life experience. The possibilities are endless. I may be totally wrong or on the wrong track, and that's probably the case, but it's a theory I can't shake...anyone care to prove me wrong?

[lio]

If someone discovered a parallel universe and told their story, who would believe them? Probably just think they're nuts, and lock them up in a psych ward.

Regular person: You can't have two things exist at the same time. Time is a straight line that doesn't overlap.
Parallel guy: Yes, it is possible. I discovered a parallel universe via time travel after an low voltage electric charge went through my body.
Regular person: That's it! You're going to the hospital until you are deemed sane.

[aaqilkhan]

Please make videos a little longer. I love hear physics

[soup]

Actually the blue fish is a male because of its tail shape and the brown one is a female for the same reason

[jeancorriveau]

This video mentions the prefect value of the cosmological constant that allows for a stable expansion of our universe, to the perfect strong nuclear force that allows for the formation of carbon, oxygen, nuclear fusion, and different kinds of chemical elements. Every thing is perfectly tuned, making it compelling to believe is some kind of purpose and design behind all of this. This belief shatters, though, at 3:05 minutes, when this video proposes the possibility of an infinite number of universes. If that is the case, then there is no need to believe in a purposeful universe because there is bound to exist universes that just happen, by pure luck, to develop the correct conditions for a viable universe. If I gave a monkey 10 years to type the entire bible, this is an impossible task, but if I gave the monkey and infinite amount of time, it is bound to succeed. When some scientists propose the existence of parallel universes, they--perhaps unconsciously--propose for an infinite number of them because it is not reasonable to assume that just a few of them exist.

[josevirrueta]

what if u put a boat in the unverse will it go faster then a rock it i wanna test it

[nesseihtgnay]

But actually dark energy is negative energy. That's why positive energy can't detect "dark energy" it's because negative energy doesn't reflect light back to us to see.

[itsusamasoomro]

Now the question is where do we stop ... stars>galaxies>galactic groups > universe > & now multiverse !!

[diGritz]

"There's at least one" If there is one then there is an infinite number of them just like ours. An infinite set inside an infinite.

But here's the catch

If there is an infinite number then every possibility must take place in at least one so again an infinite number. It's reasonable to assume that there is an infinite set of Universes with an Boltzman brain/omnipotent being. So it's plausible that the one we live in is one of them.

This is no different then evolution proving that a creator is just the logical outcome of humanity evolving to the point that we can build computers the size of a small Moon. Running countless simulation on it would effectively make us creators in our own right.

[MrBlazefp]

This is the same logic behind conspiracy theories and that's one of the reasons I don't buy it yet. Just because it could happen, doesn't it does. Statistically it's much more likely that there's something we haven't yet discovered balancing out G and lambda than having infinite possibilities and we're just lucky to be on one that works. Why would it even be plausible?

[omsingharjit]

Wow you concluded in just 4 min video which was hours long in tedtalk

[P]

Honestly that bgm is so gorgeous
I was feeling like I am into it.

[tralfamadorious]

As a premise in science fiction, multiverse is fun. But it’s an scientifically untestable idea.

[nickmiller]

What would happen if the whole universe froze for 3 seconds?

[revannoct]

My appreciation for existence just went up. Much appreciated.

[efrainjunior]

Imagine if there’s a parallel universe where Spider-Man 4 didn’t get cancelled and gets directed by Sam Raimi, and where The Spectacular Spider-Man didn’t get canceled and gets renewed for season 3.