The True Science of Parallel Universes

The True Science of Parallel Universes

Everyone loves the idea of parallel universes
– maybe it’s the appeal of an ideal world where you have second chances and things turn
out differently – an alternate reality where you do get into Hogwarts and the Star Wars
prequels aren’t made and you finally plug in your asymmetric computer cord correctly
on the first try… but is there really a place in science for such wistful speculation? I mean, if “the universe” is everything that
there is, you can’t have two versions of it, right? Otherwise the pair would really be
everything and what you started off calling the universe, wasn’t. The problem here is terminology: physicists
speaking informally often say “universe” when they really mean “observable universe” – that
is, the part of the whole universe that we’ve so far been able to see. And it’s perfectly
fine to talk about multiple different observable universes – for example, an alien near the
edge of OUR observable universe will see parts of the Whole Universe that we cannot yet see,
but that’s a well-understood question and not what physicists normally talk about when
they discuss multiple observable universes, or “multi-verses.” So let’s cut to the chase: in physics, the
word “Multiverse” normally refers to one of three distinct and largely unrelated proposed
physical models for the universe – none of which has been tested or confirmed by experiment,
by the way. The three “multiverse” models are: Type 1) Bubble universes or baby black hole
universes. This is the most straightforward kind of multiverse: the basic idea is that
perhaps there are other parts of the universe which are so far away that we will never see
them (or are inside black holes so similarly we will never see them).
This kind of model was created as an attempt to explain why our universe is so good at
making stars and galaxies and black holes and life – as the argument goes, if each of
these separate mutually un-seeable “bubbles” in the universe had slightly different laws
of physics, then by definition we could only exist in one that had the right physical laws
to allow us to exist. If you’re not convinced by this logic, don’t worry too much: there’s
not yet any experimental evidence for this kind of multiverse.
Multiverse type 2) Membranes and extra dimensions. Inspired in part by the inability of the mathematics
of string theory to predict the right number of dimensions for the universe in which we
live, string theorists proposed the idea that perhaps what we think of as our universe is
actually just a three-dimensional surface embedded within a larger super-universe with
9 spatial dimensions. Kind of like how each page of a newspaper is its own two-dimensional
surface embedded within our three-dimensional world.
And of course, if space had 9 dimensions rather than three, there’d be plenty of space for
other three-dimensional surfaces that appeared, like ours, to be universes in their own right,
but, like the pages of a newspaper, were actually part of a bigger whole. These kinds of surfaces
are called “membranes” or “branes” for short. And as a reminder, there is not yet any experimental
evidence for this kind of multiverse. Multiverse type 3) The many-worlds picture
of quantum mechanics. Surprisingly, physicists still don’t fully understand how the collapse
of the wavefunction in quantum mechanics happens, and the many-worlds hypothesis makes an attempt
at explanation by proposing that every possible alternate timeline for the universe is real
and they all happen in an ever-larger, ever-branching way. Like, a universal choose-your-own-adventure
where every possible story happens! If this were the case, we might not realize
it because we’d be stuck living out just one of the infinitely many possible lives available
to us. In some ways, many-worlds is similar to the bubble multiverse model by proposing
“maybe anything that can happen, does. And we just happen to exist in the series of happenings
that were necessary for us to exist.” If you’re still not convinced by this logic, don’t worry:
there is not yet any experimental evidence for this kind of multiverse. Of course if you want to get imaginative,
you could also combine several of these models together into a multi-multiverse… a new
super-speculative model based, itself, on speculative and experimentally unconfirmed
models. But that’s not to say we couldn’t test these
multiverse hypotheses. For example, if our observable universe were really just one of
many disconnected bubbles or membranes and if it happened to collide with another bubble
or membrane some time in the past, then that collision would certainly have had some sort
of effect on what we see when we look up at the night sky.
On the other hand, the many-worlds interpretation might be tested fairly soon since experimentalists
are becoming increasingly able to manipulate and control ever-larger quantum mechanical
systems in their labs – systems that approach the line between the quantum realm and our
everyday experience. So as always, we must remember that physics
is science, not philosophy; and in our attempts to explain the universe that we observe, we
have to make claims that can in principle be tested – and then test them!


100 thoughts on “The True Science of Parallel Universes”

  • 1101010110111111010001101110 doe says:

    Probability is simply a science that attempts to predict possible outcomes. That doesn't mean possible events will occur, there is just too many variables to make an absolutly accurate statistic. Any moment is the culmination of every cause an effect event with a very specific preset result. Parralel universes as a whole is just the result of fantastical speculation on rather unknown parts of our reality that we will probably never know existed.

  • What if in the 9D theory there was some sort of hook that they had which let them travel through the multiverse and that's why ghosts and vampire and ancient gods are a thing

  • Vince Caglianone says:

    Doesn't the many worlds interpretation defy the laws of conservation of energy? If every decision branch created both universes, then where did that energy come from to create the extra universe? And, since there have been quantum state collapses since the beginning of time, if each produced both possible conditions, wouldn't the amount of energy needed to create a new bubble universe for each quantum state collapse require energy that approaches infinite? The simplest answer is the collapse is a juncture that only produces a single outcome, not spawns an complete alternate bubble universe. It's also the one which changes energy state, neither creating nor destroying energy.

  • In a parallel universe the person we lookup to the most is us.And who knows, maybe this time they lookup to us!?

  • If you want to get a different idea about the whole parallel universes thing make sure to watch My friend has been living in an alternate reality for 7 years

  • Loser. DerpyDuck says:

    I have a thunk for the bubble theory. A 2D object cannot stand up in a 3D world. A 1D object cannot stand up in a 2D world. So we cannot stand up in a 4D world?

  • Flower flower says:

    So when I see a person I didn't see him before and I feel I know him may be I know him in parallel universe !

  • Nicolas Garland says:

    Actually, for the brane-world model, it is possible that gravitation is able to interact through (all or some of) the other dimensions, which should lead to detectable gravitationnal effetcs that we could not attribut to any visible matter (since electromagnetic force is confined in our three dimensions). And … we actually measured those evidence for brane-world model (and call it "dark matter").

  • Trexpelia Helvetios says:


    In the alternate universe, jesus told the president to kill that fucking asshole crippled and his mozarella friend

  • The Three Stooges /M.A.G says:

    I think when things move randomly like chairs and stuff it happens for a reason it could be a psychic outside of this universe or god trying to save us from something bad happening to us

  • I like to think there are universes based on fictional we made here, because there is an infinite amount of universes possible.
    So perhaps the Avengers do exist but we just can't interact

  • Ago Contealia says:

    If The Universe expands, And The Magnetic poles Shift, You stand at One Point and as the world Turns and evolves around the Sun, and the Universe Expands, You would Be at Another point in space and Time, if You was Frozen in that spot.

  • Ago Contealia says:

    I'll call the Komodo Dragon, If You Dy Tell Them They Are Welcome To Be Gay, All day, Cause it's the Happy happy joy joy Song, Monkie

  • Rafe Hayden-Lee says:

    also. There are energy forces between all atoms in the universe, this is sending exact movements to other atoms. if we place groups of…well… trillions upon billions of atoms together with other groups we could create parallel universes. but in order for thins to happen we would have to copy our world and send the signals through the energy 'wires'. not only that, but we would have to find a way to dissolve humans to 'mail' them to the other world. this is were shroedingers cat comes in. a cat that is put in a box with different death (and poisons) mechanisms. usually the cat would die… in the right universe the cat would survive. but the only way to find out if the cat is dead is to open the box… if the box is not open the cat can be either alive or dead, we can't know. parallel universes… real, but fake. we won't know until we find out…

    no cats were harmed in the proses of this comment

  • If there are infinite parallel universes, what makes our universe, any special different or meaningful? It’s just another Version that could be vastly different or similar to other parallel universes. We live our lives out like they matter and we have choice but if parallel universes exist our stories are destined and we have no control over what we do, it’s a timeline destined to happen in our universe. We aren’t special

  • Osumazi meowisfromme says:

    That means there could be an universe (or infinity slightly different universes) where you still could turn on TV and watch the good old Cartoons and Animes like YuGiOh, DB(Z) , Detective Conan, Digimon, Pokemon (1st gen), Sailor Moon, Beyblade etc. That must be a generation of lucky guys followed by another generation of lucky guys

  • If there’s a parallel universe then there’s a parallel universe where you are dying slowly while eating tree bark

  • The toadette/jirachi expert Whittaker says:

    So if there is infinite parallel universes

    Then there is a world where everyone is flat earth believers.

  • i feel like parallel dimensions are all around us, just interwoven into reality so that we cant actually see nor interact with them. we'd need to shift our dimensional perspective somehow to access it, which would look incredibly cool. sort of like an acid trip.

  • I used to really believe in all this but it gets hard of course you can do what you want and change your future or the future but it’s just life and just do what you want I guess

  • Cheeseburger Monkey says:

    In some parralel universes you have wrote, are writing, and going to write this comment right now!…and in the past and future 😉
    And you wouldnt have edited this comment
    and not have wrote this
    and wouldve wrote all of this in the future
    and not have done this and edited
    OK ok ill stop (but you wouldnt have doen this XD)
    and have wrote this in other dimension hjdddjejnexsnd
    ok now for real ill stop
    and all of these comments wouldnt have existed


    The Pillai Theory
    Every single electron, neutron, proton are made up of zillions of universes

    Uhhh, it's my own theory btw

  • Does it matter if something works or not if it works for you if it's considered a Pseudo-Science? I got a nasty email the other day regarding how the world has gone to hell because people are always coming up with a new thing to make money. This prompted me to look up the definition of a Pseudo-Science which is “a collection of beliefs or practices mistakenly regarded as being based on the scientific method.” I was shocked to find out that the majority of the tools that people use today to feel better about themselves fall under this category. Check this fraction of the list of Pseudo-Sciences… Astrology, Homeopathy, Reiki, Meditation, Visualization, Numerology, Psychoanalysis, Hypnosis, Chiropractic. My point here if it works it works. Keep up the great work. Tore Roberts

  • Andrew Marinelly says:

    I always thought the double slit experiment is proof of theories 2 and 3. If you just assume that the wave function of atoms comes about because it is multidimensional and time being one of those dimensions it could appear to act as a wave because it can be everywhere it could possibly be at any given time making it act as a wave. When you add observance to the atom it can no longer function that way as it is now displayed on "our" brane and time can only be displayed as normal entropy.

  • Mellow & WeeeGe Offcial says:

    If their even is a opposite dimension it wouldn't exist because considering that fact hat we exist the opposite of that is nothing! Nothing won't exist there

  • Wrong, physics is philosophy, cosmology. But, what scientist is supposed
    to do is eliminate that which is impossible so that you can work with that
    which is possible.

  • video take aways
    nerds (really smart scientists) are making lasers to shoot in to space and see if the get a result back

  • I’m looking for a video explaining chaos theory (similar to your thumbnail) without searching here and finding the movie or some band. Please direct me

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