400 years ago most of the people
believed that the earth was carefully
placed at the center of the universe and
that everything else the heavens were
orbiting around us somehow this
difference led people to believe that
the earth and the sky were completely
different things
but you know one day Galileo Galilei he
took his new telescope he did out there
did new observations about the night sky
and what he saw is that these
observations agreed very well with
mathematical models of copper-nickel
which basically said that we were not at
the center of the universe but rather
that we were orbiting around the Sun as
well as everything else out there so it
turned out that actually we were not
that special after all and why am I
telling you this because actually over
the last hundred years we’ve been living
a very similar situation for thousands
of years most of the people believed
that the motion that the behavior of
atoms of objects of everything that is
inner matter was behaving according to
deterministic rules basically that there
is no randomness no unpredictability in
these atoms in these objects so we think
about baseball right we take the ball we
throw it in that direction we expect the
ball is going to go out there right we
do not expect that the ball is going to
start doing random stuff in there but
for some reason that escapes our
understanding these deterministic rules
didn’t seem to apply to us somehow we
can make decisions we can behave in
unpredictable ways we have desires and
this led a lot of people to believe that
ourselves and matter are very different
things
even though we are made of matter of
course but you know observations that
have been done over the last decades
tell us that actually these atoms seems
to be a bit naughty and that every time
that we go out there and we
at them they seem to be improvising they
seem to be showing every time a
different face
they are very unpredictable over the
last five years I’ve been working on
developing quantum technologies for
cybersecurity and computation but last
year on November 30th of 2016
together with colleagues from more than
15 universities around the world we
wanted to do a new experiment to prove
whether or not atoms could improvise and
for doing these experiments we needed
something very very very special what
very special for a physics experiment is
we needed people we needed thousands of
people and why we needed them to make
choices so we built this videogame and
then we asked people to log in and then
we were asking them to make choices
between zeros and ones as fast as they
could we were taking all these choices
then and we were sending them to 13
experiments that were prepared all over
the world this project was called the
big Bell test and this is the story that
I want to share with all of you today
the story on how thousands of people and
their choices helped us testing the laws
of physics but let me start by going
first at the beginning of the 20th
century
when most of these ideas started in
those days a new theory emerged and
basically for the first time in physics
it was telling us that atoms could
improvise that atoms had
unpredictability and this theory was
quantum mechanics which basically
describes everything happening in the
scale of atoms and photons and this tiny
world you know the idea that quantum
mechanics was forcing us to give up the
idea of the Turman ISM that atoms were
had to follow a strict rules bothered a
lot of people and fascinating discussion
emerged in the physics community of
these days for instance it’s very famous
the discussion between these two
gentlemen one of them is a very
understand and the other one is Niels
Bohr two of the most important figures
of modern physics you know the
conversations were fascinating and this
that’s what we are going to do now have
God does not play dice you know this is
what other Einstein or something like
this whatever Einstein told Niels Bohr
ones and basically he was making crystal
clear that he didn’t like the idea that
objects could behave in unpredictable
ways that atoms could be improvising
he believed that any reasonable physical
Theory should be able to make this kind
of predictions and quantum mechanics
didn’t allow us so he concluded that
quantum mechanics was not telling the
whole story and that new and better
theories were yet to come in which atoms
didn’t improvise and you know in
response what Niels Bohr said is
Einstein be careful when you tell god
what to do and he probably believed that
whether we like it or not this is what
happens in there in the scale of atoms
so we better get used to these new ideas
unfortunately this was 1920’s 1930’s and
there was no way to test who was right
so everything remained in the
philosophical domain but you know in
1964 everything changed dramatically
when John Bell who was a physicist at
CERN in Switzerland he groped one of the
most important and profound theorems of
the history of physics and made a major
basically he allow us to prove who was
right whether it was Einstein who
believed that quantum mechanics was not
the whole story and that new and better
theories were to come in which atoms
didn’t improvise or whether it was Niels
Bohr who said that
this is worthless and we better get used
to these ideas and what do we need to do
about tests let me ask you a question
first I cannot see you but raise your
hand if you’ve ever heard about the
concept of entanglement or screen better
screaming entanglement is one of the
most exotic properties of quantum
mechanics and basically it tell us that
we can take two atoms two electrons two
tiny particles separate them as much as
we want we can even put one in one
extreme of the Milky Way and the other
one in the other that what’s going to
happen is that when we look at one of
them wouldn’t we measure one of these
particles there is an immediate effect
on the other without information
traveling from one place to the other
you know and this is kind of
mind-blowing there is nothing even close
in our everyday life experience and this
is why it’s hard to find good examples
but somehow is like these particles
create a connection that in the future
when we separate them we cannot do
something to one of them without the
other one noticing but going back to
what we need for doing a belters we need
three things one entangled particles
second good measurement devices to
measure these particles and three a
method to make choices about which
measurements we are going to do to these
particles over the years technological
progress has been made and it turns out
that we are very good at building these
devices but in the big Bell test we
wanted to do something different
we wanted to find an alternative to
making questions using machines or using
computers and that’s why we asked humans
to help us that’s why we built this
videogame that way we asked people to
make choices between zeros and ones and
that’s how we used all these choices and
experiments to test the laws of physics
all the experiments happened in November
30th of 2016 last year and I have to
confess that before the day I was scared
to death you know we were preparing for
over a year for this experiment a lot of
people was putting passion and not a lot
of hours to make it happen
but at the end of the day if people
didn’t show up all this effort was for
nothing but then November 30 has arrived
and the response from people was amazing
this is a density plot that shows were
the decisions where the choices were
coming from a November 30th basically
from all over the world over the course
of the project more than hundred
thousand people registered into the
video game and only in November
thirtieth nineteen million choices were
made you know if I would have had to do
all those choices myself it would have
cost me eight hours a day five days a
week four years you know so we needed a
lot of people to make this experiment
and what did we find actually a couple
of days ago we received one of the
latest and emails from one of the groups
with the result and putting everything
together we can very confidently say
that atoms are unpredictable but
basically they can improvise or somehow
that ball was right and that God looks
to be playing dice but you know the most
important thing about this experiment is
not that we proved that atoms are
unpredictable we somehow expected this
the most important thing is that in
order to prove something you always need
to state your assumptions you cannot
prove it in absolute terms and in our
case the only thing that we have to
trust is that we humans can make
decisions so if we believe if you
believe that we can make decisions then
we are sure that atoms can improvise and
I’d like to conclude by commenting on a
couple of things the first one has to do
with a question that a lot of people has
been asking over the last couple of
months and is okay but how can we use
this Bell test in practice you know
first of all Bell Theorem transform the
way that we understand the world it has
given us tools that were not there
hundred years ago and it allow us to
understand the universe in a much more
deeper level on the one hand this is
opening new research directions like
quantum information theory and on the
other hand it’s enabling exciting
application like quantum cryptography
what can we do with quantum cryptography
well we can build communication systems
that cannot be hacked then anyone can
spy on them and in a society as ours
that is built on top of information this
is of crucial importance and the second
comment goes back to what we were saying
at the beginning we said that for
thousands of years people believed that
ourselves and matter were completely
different things because somehow we
could make decisions we could behave in
unpredictable ways but matter had to
follow the terminus the growth this is
what we see in this case one but you
know a lot of people also over the
history has questioned our ability to
make choice
is our ability whether or not we have
free will so basically there is another
option in there in which neither
ourselves nor people have the ability to
make any unpredictable decision this is
the second case and is what we
understand as super determinism and
basically it means that everything that
happens in the universe everything that
will happen in the universe was pretty
established from the beginning of times
and that not even ourselves make any
decision of being here today that
everything was written in the book of
the universe this is these were the
options that people had before quantum
mechanics but then quantum mechanics
open up new possibilities in which atoms
could improvise and for instance this
could be an option in which we cannot
make any decision ourselves because we
do not have free will but matter can do
unpredictable stuff in there or this
other option in which we have free will
we can make decisions and atoms are
unpredictable
as a scientist I can not tell you that
one is better than the other but what I
can tell you is that what we proved with
the big Bell test is that if we believe
that we can make decisions then we are
sure that atoms are unpredictable so
basically is this fourth case or what is
the same that case one which a lot of
people used to believe for thousands of
years is no longer a possibility because
if we have the ability to make choices
atoms are unpredictable and you know as
a scientist I cannot tell you what to
believe either because at the end of the
day that’s your choice thank you very much