- If you're into paradoxes and
some of the most incredible and intriguing thoughts that
the greatest minds on Earth have ever come up with, keep watching. The human mind is absolutely mind-blowing. It's the greatest tool that we have. And because of that, human
beings have been able to theorize some incredible things, including paradoxes and various ideas that are absolutely ingenious. So in this video, I'm going to present you with some concepts that are
going to twist your mind. So get ready, sit back, and here we go. (light, inquisitive music) Here are 10 mind-blowing thoughts that will twist your brain. (light, inquisitive music) Number 10 is Theseus's Ship. (light, inquisitive music) Theseus's ship is a thought experiment designed to make you
question your identity. Theseus was a great hero
in ancient Greek mythology. On his adventures, he
sailed on a famous ship. Traveling the high seas and
battling monsters and gods caused wear and tear on the ship. So over time, Theseus
replaced parts of his ship which had worn out. After many years, Theseus had replaced every single part of
the ship piece by piece. So the question is, if every
piece has been replaced, is it still the same ship? Now here's what's really
gonna bake your noodle. If we take it a step further, imagine someone kept all
of the discarded pieces and put them back together. Now you have two Theseus's ships, so the question is which is the real one? The idea here is that
identity is continuous. Each person alters over
time piece by piece, and so eventually you're a
completely different person as the one you started out as. So because your body
keeps replicating cells and changing things, and
your body sheds and whatnot, are you still the same person
that you were 10 years ago, or are you someone completely
different, mind blown. (light, inquisitive music) Number nine is the Boltzmann Brain. (light, inquisitive music) To understand what a Boltzmann brain is, imagine the universe
in a far-flung future. Due to entropy and the
expansion of the universe, everything will one day no longer exist. The universe will have
unraveled from itself, leaving nothing but an
infinite amount of empty space. Except it won't entirely be empty. That space will experience
random thermal fluctuations. So if the universe is infinite, then that means every
possible configuration of fluctuation happens. And as bizarre as it seems,
sometimes these fluctuations will perfectly recreate a
temporary version of ourselves. Those are called Boltzmann brains. If they exist, it's mathematically likely that we are currently living inside one of these fluctuations. That means we're a strange
temporary approximation of people who once lived
perhaps billions of years ago. So you're you, but you're also
someone else that was you, but you're that person, but
you're only you, oh God. (light, inquisitive music) Number eight is the
Unexpected Hanging Paradox. (light, inquisitive music) Imagine a judge sentences a prisoner to be executed on a weekday next week. The exact day needs to be a surprise so the prisoner relaxes and believes that he will never be executed. His reasoning is that it
can't happen on Friday, because if he hasn't
been hanged by Thursday, then there would only be one day left, and that wouldn't be a surprise. He also can't be hanged on a Thursday, because if he hasn't
been hanged by Wednesday, then because Friday is already eliminated, Thursday would be the
only other available day, and that wouldn't be a surprise. He continues this line of logic until he eliminates each day of the week. Despite this, the prisoner
is hanged on Friday. The lesson here is that even using logic and knowing the rules doesn't mean that life will go to plan. Besides, the prisoner was
surprised like the judge ordered, all because he assumed
he couldn't be executed. Get it, because he
decided it couldn't happen because there would be no surprise, but there was a surprise because he was expecting no surprise, because the surprise
couldn't happen, oh my God. (light, inquisitive music) Number seven is Wittgenstein's Beetle. (light, inquisitive music) Wittgenstein's beetle thought
experiment goes like this. Everyone in the world
is given a small box. No one is allowed to look
into anyone else's box to see what's there. You can only look at
what's in your own box. You open up your box
and see a beetle inside. It turns out that everyone in the world has a beetle in their box,
although you only know this because they tell you what's in it. Remember, you can't look
inside anyone else's box, and they can't look inside yours. So how do you know what's in your box is the same as what's in everyone else's? The answer is you can't. Our minds are a private world
which no one can look into, just like the box. When I point at something
and say that's the color red, you might agree with me. But I have no way to know
that what you are experiencing is the same thing as I am. Literally, in other
words, what I consider red may not be what you see as red. We just assume that we're
looking at the same thing. Oh man, let that one twist your noodle. (light, inquisitive music) Number six is Quantum Immortality. (light, inquisitive music) Now this is a really
weird thought experiment. It turns out that each one of
us may actually be immortal. There are some physicists,
albeit in the minority, who genuinely believe
this is a possibility, all because of quantum
immortality thought experiments. In physics, there's a theory called the many-worlds interpretation. It suggests that at every
moment, the universe splits off into other universes, and every
possibility is played out. That means there's a universe where you moved left instead of right, or you stayed up instead of going to bed. Now some physicists believe
that each time this happens, your consciousness must
survive in the process. In other words, each
one of us always ends up in a new universe where
we continue living, and not in one that we died in. That is immortality,
kinda like Rick and Morty, and if you haven't seen
Rick and Morty yet, what are you doing with your life? (light, inquisitive music) Number Five is Laplace's Demon. (light, inquisitive music) Imagine a creature which is so intelligent that it can observe every single particle in the entire cosmos. It also has a complete
knowledge of physics. The question is could this creature, called the demon, be able to
perfectly predict the future and describe the past? Laplace's demon is
designed to make us think about whether the universe
works like a clock, determined from the very beginning. Some actually argue this to be the case, and so it's possible
to predict the future. But others claim that there's a limit on how much computational
power the universe has, so the demon would have to be outside of our universe
observing everything. And then there are those
who believe the universe is unpredictable and only
appears to work like a clock, but doesn't actually. No one really knows the truth, or if the demon is watching,
or if there is a demon. Is there a demon, Mama? (light, inquisitive music) Number four is the Chinese Room. (light, inquisitive music) Imagine being in a room
separated from another person by a wall with a small letter box in it. You need to communicate
with the other person using pieces of paper, but
they only know Chinese. The problem is you don't
speak any language of Chinese. Instead, you have a book
filled with Chinese words, and another book with
instructions in English. You receive a piece of paper from the other person written in Chinese. So you follow the instructions
you have in English and copy the corresponding
characters from Chinese, even though you have
no idea what they mean. When the other person reads your note, they think you know Chinese. But the fact is you're just
following a simple set of rules. The crazy thing is that this
is what a computer does. This experiment shows that even if a computer
appears to be intelligent, it's probably just following
a simple set of rules. So when artificial
intelligence comes around, are they simply following a set of rules created by the creator, i.e. us, or they actually able
to think for themselves? And for that matter, are we
just following a set rules, oh. (light, inquisitive music) Number three is the Swamp Man. (light, inquisitive music) David Donaldson's Swampman
thought experiment cuts to the core of who we are and the existence of the soul. The experiment describes
a man walking in a swamp. Suddenly a flash of lightning
comes down from the sky and strikes the man,
killing him instantly. The body sinks into the swamp. At the same precise moment, another lightning strike happens nearby. The lightning rearranges the atoms nearby into the exact replica of the man. He brushes himself off
and leaves the swamp, believing that he's the same person. But he question is, is he the same person? Is the original person gone? And does the new version have a soul? It's similar in some ways to
the ship of Theseus paradox, and questions whether we're
actually the same person when we wake up every day, or just a new piece of consciousness which has the same memories. What you think is you may
not have been you yesterday or the day before. You may be changing
bodies, oh, I don't know. (light, inquisitive music) Number two is the Simulation Theory. (light, inquisitive music) Imagine we run a virtual
reality simulation which is indistinguishable
from the real thing. We create an exact replica of Earth, and we populate it with
computer-generated people. Now ask yourself this. What are the odds of you being
in a real world right now, or being one of the simulated
people in a virtual one? It's one out of two, right? Now we run two simulations. What's the odds that
you're a biological human? It's about one in three. Now imagine that there are thousands of these simulations running,
and that there are millions of alien civilizations
running simulations as well. The chances that you are in a real world as opposed to one of the billions of simulations is actually tiny. Mathematically it's
likely that you are living in a simulated world right now, and that you're not
even a biological being. This is the simulation theory,
and it's kinda terrifying. Seriously, look up the
simulation theory on YouTube or just look up simulation
theory Elon Musk. Your life will never be the same. (light, inquisitive music) And number one is Schrodinger's Cat. (light, inquisitive music) One debated theory in quantum physics is that the universe hangs around in what's called superposition
until someone looks at it. Superposition simply means
that every possibility is happening at once. Once a conscious observer looks at it, the universe collapses
into one solid outcome. Schrodinger's cat involves a cat in a box with a vial containing
a radioactive substance. The substance has a 50% chance
of decaying in one hour. If the substance decays, a mechanism releases poison gas into the box. Now without looking in
the box, you have no idea if the cat is dead or alive. In fact, because a conscious
observer isn't looking, the radioactive substance
is in superposition. It's both decayed and not decayed. The poison has both been
released and not been released. And that means that the cat is both dead and alive at the same time. Oh, I need to lie down, bye. (light, inquisitive music)
