Category
😹
FunTranscript
00:00A scientific theory is defined as a testable and verifiable prediction using the scientific
00:05method to observe, measure, and evaluate specific aspects of nature.
00:11Experimental verification is how we determine a theory's truth.
00:14But not all popular theories are easily testable.
00:18This is Unveiled, and today we're taking a closer look at 10 Scientific Theories That
00:22May Never Be Proven.
00:24Do you need the big questions answered?
00:26Are you constantly curious?
00:28Then why not subscribe to Unveiled for more clips like this one?
00:31And ring the bell for more thought-provoking content!
00:35White holes.
00:36Of course, we've all heard of black holes.
00:39These are objects in space with a density so extremely high that even light can't escape
00:43from them.
00:44But there are also predictions to a black hole's exact opposite, called a white hole.
00:49White holes are hypothesized objects which can't be entered from the outside, but light
00:54and matter can still escape.
00:56And in fact, it endlessly escapes, much as it endlessly gets drawn into a black hole.
01:02The problem is that to an observer, it's believed that white and black holes could
01:06well appear identical.
01:08The white hole is spewing matter out, yes, but the difference from our perspective may
01:12well be impossible to confirm.
01:15And on top of this, if white holes were to exist, then they violate the key principles
01:20of thermodynamics, which say their contained mass has to come from somewhere originally.
01:26That said, for those who claim white holes to be real, that might not be a problem…
01:31so long as we accept that somewhere could be outside of the universe we live in.
01:35It's not a ghost.
01:38It's gravity.
01:41The inner workings of a black hole.
01:44While the existence of black holes is a complete certainty by now, we remain almost entirely
01:49unaware of what happens within them.
01:52To us, black holes have two main components, the event horizon and the central singularity.
01:58Event horizon marks the point of no return.
02:01Once crossed, nothing at all can exit from the black hole, not even light.
02:05We can then predict what it would be like to approach the horizon, which involves a
02:09grisly process called spaghettification.
02:11However, we have no idea about what lies after, between the horizon and the singularity.
02:18Or at the singularity itself.
02:20A few theories attempt to explain.
02:23For example, some think that black holes may contain universes of their own.
02:27Others say that the centre may actually be a bridge to a separate universe entirely.
02:32But it may forever be impossible to actually test whether any theory is close to the mark.
02:38So what next?
02:40Prove it?
02:43Wormholes.
02:44Always popular in science fiction, these ultimately derive from the same overriding theory
02:48as black and white holes do, that of general relativity.
02:53Wormholes are tunnels between distant places in spacetime.
02:56They potentially link up the universe in infinite ways, and could therefore offer a solution
03:01to the seemingly unscalable immensity of space.
03:05It's exciting, then, that certain solutions to Einstein's equations do predict wormholes
03:09to exist… but it's disappointing that we've yet to actually observe them.
03:14One of the greatest issues is that, for them to exist, and to be traversable, they'd
03:19need to be made out of exotic matter.
03:21This is essentially an entirely unknown product, and so it's also a huge mystery.
03:27In theory, wormholes would enable us to travel to a completely different location in the
03:31universe.
03:32It's thought that they would also, inevitably, send us forwards and backwards in time…
03:36but in reality, we simply may never unlock them.
03:40And as well as everything else, it's predicted that they may only ever exist on microscopic
03:46scales, which, if nothing else, is impractical.
04:01The Big Bounce How, when, why, and where did the universe
04:05begin?
04:06In terms of big questions, it's arguably the biggest of them all.
04:10Famously, the Big Bang Theory has a strong amount of evidence in its favour, and is therefore
04:14the most widely accepted theory for creation.
04:17But despite this, we still have very little understanding as to the very, very first moments
04:22of it.
04:23There's a crucial gap that needs to be plugged.
04:26And one interesting answer arrives out of the wider, Ekpyrotic Universe Theory.
04:31It claims that the Big Bang wasn't a bang so much as it was a bounce.
04:35The material of the universe didn't erupt out of nothing, but rebounded out of something.
04:41This is a cyclical model, meaning it predicts the universe to follow infinite, self-sustainable
04:46cycles, beginning with a Big Bang and closing with a Big Crunch… which is where the expansion
04:52of the universe reverses and collapses in on itself entirely.
04:56Currently, observations show that the universe is expanding out at an accelerating rate,
05:02which means that we're certainly not approaching a Big Crunch.
05:05However, that's not to say that the situation will never change.
05:09Many believe that it inevitably will, and a crunch to bounce will ultimately unfold.
05:14From a human perspective, though, this will most likely be long, long, long after we've
05:20disappeared.
05:21There ought to be something very special about the boundary conditions of the universe.
05:27And what can be more special than that there is no boundary?
05:33And there should be no boundary to human endeavour.
05:39The Fermi Paradox
05:41Okay, so it's not a theory, but it's a major problem that may never be solved.
05:46The Fermi Paradox questions the disparity between the high probability of alien life
05:51and the complete lack of evidence of such life.
05:53Originally proposed by Enrico Fermi during his lunch break in 1950, it has since baffled
05:59astronomers.
06:00Humans evolved roughly 300,000 years ago, and the solar system is 4.5 billion years
06:05old.
06:06So, statistically, life should have done the same on other planets.
06:10But despite this, we have zero definitive evidence of extraterrestrial life.
06:15A few explanations exist to explain this, the simplest being that space is simply too
06:20big to travel.
06:22Another says it's extremely unlikely to develop basic life in the first place.
06:26Whereas the more pessimistic answers suggest that global civilizations struggle to survive,
06:32meaning that eventually, we will fail as well.
06:35This could be due to global warming, nuclear war, or thanks to an endless list of other
06:39gloomy factors.
06:40However, the fact remains that any answer to the Fermi Paradox will only ever amount
06:45to an unproven theory until such time as we do find alien life… if that ever happens.
06:52What is hell?
06:54Not Clarence.
06:56It was our enemy.
06:59The Simulation Hypothesis.
07:01First put forward in its current guise by the Swedish philosopher Nick Bostrom in the
07:05early 2000s, the Simulation Hypothesis is actually a specific, potential answer to the
07:10Fermi Paradox.
07:11However, more than that, it suggests that our reality is fundamentally false.
07:17Or at least that there are higher dimensions above us, directly pulling the strings.
07:22It argues that our entire universe is simulated by something else… with some suggesting
07:27that it might be an inevitable conclusion to draw.
07:31The idea goes that if a reality like ours can be simulated, then statistically we are
07:36almost certainly in one ourselves.
07:39Such simulations would require extremely powerful computing technology, far beyond that which
07:45we currently have or arguably can imagine.
07:48But because we can't know if there's a limit to what computing can do, we can't
07:52truly know if the Sim is real.
07:54There's no realistic way to measure if we're in it or not.
07:57So if it feels real, we might as well accept it as such, because we're unlikely to prove
08:02anything else.
08:04The Matrix is a computer-generated dream world, built to keep us under control in order to
08:13change a human being into this.
08:18String Theory
08:19Elementary particles, such as electrons and photons, are the smallest particles known
08:24to humanity.
08:25But are these really as small as matter gets?
08:28String theory famously ascertains that we have even smaller bits, or strings, that then
08:34make up the smallest particles that we're aware of.
08:37The key is that these strings vibrate, and it's their vibrational frequencies that
08:42determine what particle they will form.
08:44Mathematically, it could be said that string theory makes a great deal of sense.
08:48But physically?
08:49For it to work, we would need many, many more dimensions to house and explain it.
08:55In the most widely-debated variations, we'd need ten, eleven, or twenty-six in total.
09:01Some then think that these extra dimensions might be too compact to see, and therefore
09:06to prove the existence of strings could be beyond human technology.
09:10In some imaginings, to do so would require a particle collider much grander than the
09:15Large Hadron Collider in Switzerland, and potentially even bigger than the solar system.
09:21It's a theory, then, that may never be finalized.
09:35Many Worlds
09:36Alternate dimensions, parallel to our own, are common in science fiction.
09:40Increasingly, they're commonly debated in science fact, and various models to generate
09:46them do now exist.
09:47However, perhaps none has caught the imagination quite so much, nor for so long, as the Many
09:53Worlds Interpretation, put forward by Hugh Everett III in 1957.
09:58In short, it says that all possible scenarios come true in at least one world.
10:04If you ever find yourself choosing between left and right, an apple or an orange, to
10:09get up or stay in bed, the one that you don't choose still happens elsewhere.
10:14Dial it down to the very smallest parts of reality, though, to the quantum superposition
10:19of a wave or particle between two states, and the possibilities are truly endless.
10:24Now the implication is that there's an incredible quantity of parallel universes out there.
10:29Perhaps the most famous depiction of many worlds comes via Schrodinger's Cat, which
10:33is notoriously both dead and alive simultaneously, until it's observed.
10:38The problem is that because, theoretically, both outcomes will become true in their own
10:43branched-off universes, Many Worlds is, by its nature, completely unprovable.
10:48And at the same time, completely unfalsifiable.
11:01Dark Matter and Dark Energy One of the most bizarre realisations of modern
11:05times is that most of everything is invisible.
11:10Observations show that the majority of all the galaxies matter, all the universes even,
11:15is unseen and not directly measurable.
11:17The universe's expansion is also effectively driven by an invisible energy.
11:22These phenomenon have come to be known as dark matter and dark energy, respectively.
11:27And while all evidence shows there to be something there when we gaze out into reality
11:31as we know it, we know almost nothing more than this.
11:35Currently, we think 95% of the universe is made of dark matter and energy.
11:40Only 5%, or just less than, is everything else we see and know.
11:45This is pretty mind-blowing, especially as we have almost zero idea toward learning how
11:50to start seeing what we can't at the moment.
11:54Yes, we can muster up some level of understanding through indirect observations, but we just
11:58can't seem to interact with dark matter or energy in any clear, understandable way.
12:04It's a mystery that's so entrenched in what it means to be alive in our universe
12:08that many believe we might never, ever solve it.
12:22The Fate of the Universe How, when, why, and where will the universe
12:26end?
12:27Or, indeed, does it need to ever end at all?
12:31Just as with the start of all things, the fate of the universe has long been a topic
12:34for serious consideration.
12:36And unsurprisingly, more than a few ideas have been proposed.
12:40So-called heat death ranks amongst the most popular.
12:43It says that the cosmos will expand until all particles are an infinite distance away
12:48from each other, which eventually should lead to a total loss of energy and to a somewhat
12:53disheartening end to nature, as the final stars and objects fizzle out.
12:59Dark energy again rears its unknowable head as the primary driving force of the expansion
13:04towards heat death.
13:05That said, such infinite stretching out isn't the only solution.
13:09There's the crunch and bounce, as mentioned earlier, but also the big rip.
13:13Here it's said that expansion will eventually tear the fabric of space-time itself.
13:18Exactly what will happen to the remnants of this place is unclear, but what we can say
13:23with a decent degree of confidence is that if the universe does end, then humans are
13:27unlikely to be alive for it.
13:30But of course, that means that whatever happens, we'll potentially never be able to prove that
13:35it's going to happen, either.
13:37This is space.
13:38It does not cooperate.
13:41At some point, everything's going to go south on you.
13:44Everything's going to go south, and you're going to say, this is it.
13:47This is how I end.
13:49What do you think?
13:50Is there anything we missed?
13:51Let us know in the comments, check out these other clips from Unveiled, and make sure you
13:55subscribe and ring the bell for our latest content.