Does Quantum Physics PROVE Parallel Universes Are Real?

Unveiled

Watch Does Quantum Physics PROVE Parallel Universes Are Real? - Unveiled on Dailymotion

Transcript

00:00Parallel universes are an increasingly popular topic in science fiction, with a lot of modern

00:05media using quantum mechanics as a mode to explore them.

00:08But in reality, does quantum physics actually predict parallel universes?

00:13And if so, is there any definite way to prove this through the mathematics of the quantum

00:17realm?

00:18This is Unveiled, and today we're answering the extraordinary question, does quantum physics

00:23prove parallel universes are real?

00:25Do you need the big questions answered?

00:28Are you constantly curious?

00:29Then why not subscribe to Unveiled for more clips like this one?

00:32And ring the bell for more thought-provoking content!

00:36The many-worlds interpretation of quantum mechanics is a relatively new concept, but

00:40the general idea of parallel universes is much older.

00:44To some degree, the notion of an infinite multiverse was first hypothesized by ancient

00:49Greek atomists over two and a half millennia ago.

00:53These old-time philosophers believed our world to be the accidental result of completely

00:57random collisions between atoms in a vacuum.

01:01These random collisions then, in turn, they said, caused an infinite number of other worlds

01:06and universes, which led to the most primitive theory of a multiverse.

01:11These philosophies were still a long way from our contemporary view on how parallel universes

01:15should work, mostly because the scientific method hadn't been developed yet, i.e. testing

01:21your claims mathematically and experimentally.

01:24Without Arabic invention, it wouldn't arrive until the eleventh century.

01:28Of course, the scientific method is now widely practised.

01:31So, unlike the Greeks of old, today we can actually test the legitimacy of any multiverse

01:37hypothesis.

01:38And before we get into the world of the very small, it's important to note that ideas

01:43on the multiverse aren't solely a product of quantum physics.

01:47Multiple universes are predicted in other fields, too, such as in cosmology, where it's

01:51a contentious product of cosmic inflation.

01:54As there's no such thing as a unanimously agreed-upon theory to explain the inflation

01:59of the universe, there are gaps to be filled.

02:02And based on models originally proposed by the theoretical physicist Alan Guth in 1980,

02:08there now exists a range of inflationary theories, with a fair few needing a multiverse to work.

02:14For the most part, advocates believe the inflation of the universe to be eternal.

02:18However, it's also thought that there are small pockets where inflation halts, as well.

02:23These pockets lead to bubbles on a truly massive scale, and these bubbles can then safely contain

02:29an entire universe, such as our own.

02:32It's a claim that's by no means universally accepted, though, and a great deal of cosmologists,

02:37such as Stephen Hawking, believe it to be unscientific.

02:40One of the last papers published by Professor Hawkins was on this topic, and it suggested

02:45that cosmic inflation need not lead to an infinite multiverse.

02:49So, moving forward to another field, and string theory also predicts a multiverse, although

02:55a different type.

02:56In general, string theory is the proposal that the most fundamental object in the universe

03:00is a string, and the frequency it vibrates at determines its particle type.

03:05In other words, reality as we know it, at the bottom-most base layer possible, is built

03:10of vibrating strings.

03:12For it to work mathematically, certain types of string theory require at least eleven dimensions,

03:17and one potential explanation for this is that our four-dimensional universe, everything

03:22we see and know, is localized on a 4D object called a D3 brain, which is then thought to

03:29be floating in a higher-dimensional region, a space that's believed to contain a multitude

03:33of other brains, all with different dimensions and properties.

03:37In some tellings, this higher-dimensional realm is known as the Bulk, for the purposes

03:41of a multiverse, though, all these other, predicted brains could also contain universes

03:47of their own.

03:48Ours is simply rendered along our own brain, while countless others exist elsewhere.

03:52Again, though, string theory is far from being universally accepted… or experimentally

03:58verified, and some believe it will never even be possible to prove that string theory is

04:03correct.

04:04And so, let's head back to quantum physics, which does of course play a vital role in

04:08cosmology and string theory from the off.

04:10However, quantum mechanics itself also predicts its own multiverse.

04:14For the most part, we're back dealing with the many-worlds interpretation, but it's

04:18far from a smooth course.

04:20First, let's look at how we arrived at many worlds.

04:23The quantum multiverse theory comes from many of the most fundamental ideas in the field,

04:28although applying them to mean multiple universes wasn't always immediately obvious.

04:33Many of the key ideas were formally established in the 1920s.

04:37One, called a superposition, was actually first discovered a while before, in Thomas

04:42Young's double-slit experiment in 1801.

04:45This is probably the most commonly taught experiment in the history of physics, yet

04:49it's one that we still don't fully understand.

04:52What we do know is that it proved light can be modelled as both a wave and a particle

04:57– an idea we've since labelled wave-particle duality.

05:01The experiment involved firing photons through two parallel slits towards a screen, and then

05:06observing which paths the particles took.

05:09As it turned out, the photons would go through both slits simultaneously, creating a pattern

05:14of light and dark fringes.

05:16Confusingly, it was, and is, the act of observing the particles that determines what slit they

05:21pass through.

05:22Thus, we cannot say the location of these fringe patterns until we observe them.

05:27And before this observation, the outgoing photons are peculiarly assumed to be in a

05:33superposition of all spots on the screen.

05:36It's heavy stuff, but what it ultimately means is that, at its most fundamental, light

05:40can be more than one thing at once.

05:43Little did Young know back then, but this realisation could well be considered the very

05:47first indication of the multiverse… the very first step taken along a path to an infinity

05:52of parallel universes.

05:54Clearly, such unknowability isn't what common sense would expect, and it defies our understanding

05:59of classical mechanics… so the double-slit, and all that followed, led to a lot of hair-pulling.

06:05The math was by all accounts correct, but how?

06:08The fact is that the quest for an answer is still ongoing.

06:11Nevertheless, as Young's experiment shows, we simply can't predict the results of quantum

06:16experiments with complete certainty.

06:18And it's this which led to the proposal of the many-worlds interpretation.

06:22In short, it claims that at the quantum level, all possible outcomes result in new universes.

06:28The theory was first pitched in 1957 by the American physicist Dr. Hugh Everett, who believed

06:34that our reality is constantly splitting into a superposition of endless other realities.

06:39The never-ending quantum splits are the key, as naturally, they just keep going, and going,

06:45and going.

06:46Ultimately, inevitably, they should lead to a multiverse of unfathomable size, with parallel

06:52universes existing upon branches, upon branches, upon branches of an infinite dimensional space

06:58– otherwise known as a Hilbert Space.

07:01Within this immense structure, every single possible state exists simultaneously, in parallel.

07:07And again, for those who claim it to be true, the only evidence we need can be traced back

07:11to the Double-Slit Experiment.

07:13Finally, though, all of this clearly has some serious implications about the nature of time.

07:19In this world, our world, here and now, the true power of time will hopefully be explored

07:25in the future.

07:26However, for now, we can see that if there were a quantum multiverse, then it may well

07:31be that within its infinite nature, time as we know it falls apart.

07:35Yes, it's a fundamental driver for how we understand reality… but we are but one tiny

07:41strand in an unknowable, wide web.

07:44Does time work the same way across it all?

07:46Or only here?

07:48Or only in some parts, but not others?

07:50The problem with infinity is that it should mean that anything's possible, and perhaps

07:54even that time is irrelevant.

07:57The disappointing news is that currently, there are no clear ways to test for a multiverse.

08:02The scientific method relies on being able to experimentally test a hypothesis, and without

08:07a means to do so, a theory can't really progress beyond speculation.

08:10It's why, at this stage, many scientists are inclined to dismiss the question of a

08:15multiverse entirely.

08:16Nevertheless, it's a question that's not going away.

08:19For some, it just makes too much sense to deny, and at the very least, it'll continue

08:24to underpin alt-theories, science fiction, and fierce, potentially world-changing, debate.

08:30What do you think?

08:31Is there anything we missed?

08:33Let us know in the comments, check out these other clips from Unveiled, and make sure you

08:37subscribe and ring the bell for our latest content.

Category

Transcript

Recommended