A mad scientist has captured your friend and implanted some kind of brain control
device. She enters commands into a machine and your friend has no choice but to
follow them. Most of us would say that he doesn't have free will
as someone else is now controlling all his actions. But what if the scientist
got a bit lazy and decided to put the machine on autopilot and have a set of
roulette wheels decide his behavior? With this addition of randomness does he now
have free will? Most of us would still say no. Author Sam Harris in
his book The Moral Landscape argues that this is the state we're all in now, and that
instead of roulette wheels our actions are decided by the unpredictable desires
of our unconscious brains. But physics has a different argument against
free will and it's the idea of determinism. That events in the future are
caused by events in the past. If we follow that logic all the way back to
the beginning of the universe it's reasonable to say that everything that's
happened from the Big Bang up until now is a chain of events resulting from the
way things were in our early universe. That specific arrangement of gas and
molecules led to the formation of the planets, which led to the creation of life,
which led to the evolution of man, which eventually led to you watching this
video. This idea is called the Newtonian clockwork universe and it's what
Einstein meant in his famous words "God does not play dice". From a completely
Newtonian point of view we have every reason to believe that we live in a
predetermined universe. That what you had for breakfast this morning was already
decided billions of years ago in the arrangement of molecules. But if that's
true then why do we have such a hard time predicting the future? We know all
of the equations that describe the behavior of the largest planets to the
tiniest atoms, so why don't we know if it will rain a week from now?
Well let me tell you a story about an American meteorologist named Edward
Lorenz. One day he was using an LED desktop computer to model weather patterns.
After running a simulation he wanted to repeat it so he put the same numbers
into the computer, but to his surprise the outcome was totally different. Why? In
the first simulation Lorenz had entered his numbers to six decimal places but in
the repeat the computer rounded it off to just three. Lorenz had expected that a
difference as small as 0.000127 would it have much impact, but it did. It
changed the weather pattern in a totally unrecognizable and unpredictable way.
This is commonly known as the butterfly effect. The idea that a butterfly
flapping its wings can cause a tornado on the other side of the world. It's
important to note that the wind from the butterfly isn't what causes the tornado,
but billions of tiny interactions in between that may not have occurred if it
wasn't for that flap. This kind of behavior is seen everywhere in nature from the
weather to the motion of galaxies, how animal populations grow and decline and
the beating of our hearts. So we can see that even tiny inaccuracies lead to huge
changes in even pretty simple systems. The unexpected relationship between
determinism and predictability is called chaos theory and it highlights how
perfectly logical steps can lead to seemingly random behavior that isn't
really random at all. So does this mean the universe isn't determined? Well no, if
we played it back and started in the same conditions it would play out the
same every time. It just means that in practice we would never be able to
measure anything to 100% precision so the final outcome of even simple systems
remains a mystery to us. Okay so we can't predict things
because it's physically impossible to get all the information, but what if it
weren't? What if in the future a supercomputer was built that could know
the exact position and state of motion of all the atoms in the universe to
100% precision? You have this computer and you find out some people you know
are going to a movie tomorrow night. You're not really in with this group so
aren't sure if you'll be invited. You ask the computer
"Will Dana and her friends invite me to the movies tomorrow?" It measures all the
particles in the universe, including the neurons in Dana's brain and says yes! But
you get a bit overexcited and start acting weird which ends with Dana not
inviting you to the movies. But if the computer had said no you would have been
a bit disappointed but it's gotten over it and gone off to do your own thing.
This cool attitude would have led to Dana inviting you to the movies after
all. So the supercomputer can't give you an
answer without changing your behavior. Basically because it's interacting with
the universe it has an impact on it so it can make correct predictions, it just
can't tell you about them without changing them. So what does this mean for
free will? If the unfolding of the universe is predetermined all the way
back from the Big Bang, does that mean we have no say in our fate and all the
actions and thoughts we're going to have have already been decided by gas clouds
and molecules billions of years ago? Einstein thought so. After all, the brain
is also made of atoms following the same laws of physics. But others believe that
we do have free will thanks to quantum physics. Uncertainty and randomness seem
built into the behavior of quantum particles. The quantum world is very
different to our daily world and the equations that govern pool balls and
planets are totally useless there. But as with the mad scientist and roulette
machine, does this randomness really equal free will? Others think, sure, it
may save us from a deterministic universe,
but the fact that we have no control over this randomness means we have just
as little control over our actions and choices. But legendary theoretical
physicist Stephen Hawking holds a different view. That free will is saved not
by quantum mechanics but by chaos theory. If the laws of physics really do govern
all our actions they do so in a way that's impossible to calculate,
especially for an organism as complex as the human. What gives us free will is
our inability to predict what we'll do next, so the choices we make are, to us,
real choices. Which of these points of view you subscribe to? You're free to
agree or disagree with any of them in the comments below, or are you?