Marcelo Gleiser: “The Island of Knowledge” | Talks at Google

MALE SPEAKER: Thank you all for
stopping by to another Talks at Google presentation. This afternoon’s talk is
with Marcelo Gleiser, who is a Professor of Physics and
Astronomy at Dartmouth College, and he’s made
numerous contributions to research and science
in the popular eye. His contributions to
physics and cosmology include being the
co-discoverer of oscillons, and of the publishing
of numerous articles. And his research and his
books have actually wound up in the publishing of four books,
including “A Tear at the Edge of Creation” and “The
Dancing Universe.” Today he speaks to us on
“The Island of Knowledge,” which blends science
and philosophy to trace our search
for the answers to life’s fundamental questions. And we’ll have some time
for Q and A at the end. So please join me in welcoming
Professor Gleiser to campus. Thank you. [APPLAUSE] MARCELO GLEISER: All right. Thank you all for coming. I have been told that there
are about 4,000 other people from Google watching remotely
so it’s really awesome. Thank you very much, guys,
for being there for me. You know, it’s really great. And the other thing
which I wanted to make a remark, which you
guys may or may not know, that there is this real hot
debate going on in academia right now about should students
take laptops to class or not. It’s a big one, you know? And it’s a complicated question,
actually, to deal with. So what I want to talk
about today– and my plan is to talk for maybe
30 minutes or so, so we have time for questions,
which is, to me at least, the more fun part. I will talk about ideas from
my last book– latest book. Hopefully not the last book–
on really big questions. OK? So this book is dealing
with what is reality and how can you tell. And because reality is so much
related to the nature of truth, really the book relates
how we can figure out truth and does science
actually lead you towards that kind of big
T formulation of what we know in the world. And the answer is
kind of humbling. So what this is, is an exercise
on how science actually works. You know, it’s what philosophers
like to call epistemology. How do we acquire
knowledge of reality? And so the first fundamental
point is the following. How do we know that you’re here? How do you know this
is happening right now? Well, you know, you have these
amazing sensor apparatus, right? You have your eyes,
and you have your ears so your organs are
picking up the information from the environment, right? And they are bringing this
information into your brain. And your brain is
this amazing thing that can integrate all
this sensor information and construct this
cognitive image and impression of
what reality is. So what we call reality– at
least from a more immediate way, as humans– is this sum
total of the sensor integration that is happening in
your brain, right? And, of course, the point
is that that is really not all of reality at all. That’s just a tiny
little fraction of what reality is about. And what else is going on? Well, you know that
right now there are tons of electromagnetic
waves going to this room. You know, all the FM and AM
radio stations from the areas around here. You have ultraviolet
radiation from these lights. You have infrared radiation
that you guys are beaming out, because we’re all
warm bodies and when you’re a warm body at about
98 degrees Fahrenheit, you’re beaming
infrared radiation. But all these things
you cannot see. But the fact that
you can’t see it doesn’t make it
less real, right? So in a very concrete
sense, science is an effort to amplify
the way we see reality. Right? There’s this little line
from “The Little Prince” where the fox is talking
to the Little Prince and says that what’s invisible
is essential to the eye. And essentially
science is trying to uncover– at least
modern science– is trying to uncover
this invisible. Kind of opening our eyes to
what’s going on out there. So I wanted to kind
of set the mood with a quote from the master
himself, from Albert Einstein, and I see there is a
Google equals mc squared over there, which
is really cool. I had to take a picture of
that to show my students. But what he says is the
following, “What I see nature is a magnificent structure that
we can comprehend only very imperfectly, and that
must fill a thinking person with a
feeling of humility.” And what he is
trying to say there is almost against
what he believed. Right? So Einstein was a
realist so he thought that there is order in
nature and that there is some sort of pattern that
we can uncover with our minds. And it’s just a matter
of working hard at it, and you can figure things out. That nature– as
you probably heard before– he is famous for saying
that God doesn’t play dice. He wasn’t talking
about any real God. It was meant nature
cannot be random, cannot be unpredictable. There has to be a fundamental
order underneath everything. And yet, he also recognized
that as humans we can only go so far in
understanding the world. Right? And so, in that sense, you can
understand things imperfectly, and you should have really a
feeling of humility, meaning you should be humble to
understand that you really don’t know. There’s another
quote from Einstein, which I think is relevant
in this context, which is this one. “The first thing we can
experience is the mysterious. It is the fundamental
emotion which stands at the cradle of
true art and science. He who does not know it
and can no longer wonder, is as good as dead.” So basically what he’s
saying is, wake up, people. There is all this awesome
unknown stuff out there. What he calls the
“mystery,” what’s out there in nature
that we do not know. And if you’re not excited by
trying to figure that out, then you’re just not alive. You know? That’s just not happening. And furthermore, it is this
kind of seductive power that we have to this mystery,
to what we want to figure out, that is the creative
engine behind so much art and so much science. So he’s bringing this
sort of human urge to understand into this
big umbrella, right? Putting all our creative output,
be it artistic or scientific, under this big
umbrella, which is this engagement
with the unknown, with the mysterious, which is a
very interesting position which I share. And then we have this picture
here of the fish in the bowl. so here’s the little fish,
and we– at least when I look at it, I go, to me
it’s a beautiful picture. But it’s also kind
of sad, right? Because you look at the fish and
say, poor little guy, you know? His universe is so confined. Right? He is in that little bowl. That’s all he sees. I mean, he can kind of
glimpse through the glass and there is some
stuff out there, but he can never get to it. Much better to be the
photographer, right? To be the guy on the
outside that can actually take that picture and see the
sunset and understand that, hey, my reality is much
richer than that of the fish. And the point I’m going to make
is it’s not really, you know? That our reality is kind of
exactly like that of the fish. And so when we go
conceive the world and understand what
is the world like, you have to be very
careful to measure where you want to take this statement
this is what reality is about. There is such a thing
as a fundamental reality that we try to uncover. And I speak to this being a
theoretical physicist that works in cosmology and high
energy physics, which is really of the big bang and black
holes and Higgs particle. That’s the kind of
stuff I do, and I will be happy to answer
questions about that later on. But it’s important to
understand that when we try to push the
boundaries of knowledge, we are always going to
hit a certain wall, which is the wall of what we can do
to understand what’s going on. And furthermore– and
here I quote Heisenberg, who is one of the architects
of quantum physics– he says something
very important. He says, “what we observe
is not nature itself but it’s nature exposed to
our method of questioning.” And that’s really interesting,
because what he’s telling here is that there is only a human
way of understanding things. There is no universal way
of understanding things. That kinds of rubs
against our notion that there is such a thing
as some universal truth out there, right? That we should be able
to get to that and that is beyond the human frame. So that if an alien intelligence
can do physics or chemistry, they are going to come up with
laws of nature which are just like our laws of nature, right? And what he is saying
here is something like, perhaps the content
of those laws is similar, but the way they’re
going to be expressed as completely different. There is a very human way
of probing reality, right? That we are animals that
evolved in a very specific set of circumstances. We have a star, about 150
million miles from us, and it has a temperature–
a surface temperature– of about 6,000 degrees
Celsius, which makes it glow white-ish yellow. And so any form of
light– of life, sorry. Any form of life that
evolved in this planet had to maximize the way it
could capture this radiation, and hence we and most
of the animals around us can see in this
very tiny window all of the electromagnetic
spectrum, which is what we call
the visible, right? From the red to
the violet, right? And that makes sense, because
if you could see in radio waves or in microwaves, you know,
when a tiger comes to you, you’re going to be eaten. So it doesn’t really
work very well from a survival perspective. So it’s no wonder that our
eyes can capture the most power output that the sun can put out. And so when we try to put
these things in context, we want to understand what
is science trying to do. And there is this philosopher
from the 17th century, which is really an awesome guy,
called Bernard Le Bovier de Fontenelle. So the same year that Newton
published his “Principia,” which is the book that changed
the wall, in a sense, right? It was the book where the laws
of motion, the law of gravity, was written. In 1686, this French
philosopher wrote a book on the possibility of
life in other planets. And it is a really
interesting book, because it’s constructed as
a dialogue sort of inspired by Plato. But in that book he
has two characters. He has the philosopher,
which is himself, and a co-protagonist which is a
woman– who is a woman– which is a very, very rare thing
in the 17th century, who is much smarter than
he is in a sense that she has this sort wit. And there is this
dialogue between them in which she is always
questioning his assumptions from a natural
philosophical, which is the old name for a
science perspective. And this guy says
the following, this is how he summarizes the problem
with trying to figure things out from a scientific
perspective, OK? So he says, “all philosophy
is based on two things only: curiosity and poor eyesight.” Right? And I think that’s
just brilliant, because that is exactly right. I mean, we are super curious. We want to understand things
the best possible way. More and more, right? More information–
you guys know this better than I do how
hungry people are all the time for more
and more information. And yet, we are myopic, right? I mean, there is only so
much we can see, right? And there is a tension here
about wanting to know a lot and not be able to everything. And from this creative tension
comes the output from science, right? So this poor eyesight
also has to do with our perspective of
what reality is like. So now I switch gears and
I go back to 400 years or so before Christ
to Plato’s cave. OK? So Plato, in his “Republic”–
in book seven of “Republic”– he wrote something called the
allegory of the cave, which is absolutely a brilliant kind
of way of thinking about what is the nature of reality
and how can we know? OK? And the notion is about
more or less the following. Let’s imagine that we
are inside a cave, OK? And you guys are the
slaves, because that’s how Plato framed the stuff. And the slaves were born
chained in such a way that all they could
do is look forward. OK? So all you could
do is look forward to what’s being projected on
the cave wall in front of you. Right? So for these slaves, reality
was what they could see in there and on this cave wall. That was reality. Now, they didn’t know
that behind them there was this big, big fire. A roaring fire, and a
bunch of philosophers are holding stuff up, right? And the projection– the
shadows from these objects were being projected
on the wall, right? And what the slaves saw
was just a projection. So they would say,
like, you know, yeah, this is like one shape. When they have no idea
that the true shape is like a rectangle, so to speak. And so here’s a
variation on that is when Neo visits
Plato’s cave, right? Neo from “The Matrix,” right? And as you probably know–
if you don’t you probably couldn’t get a job here, right? So in “The Matrix,”
people thought they would be seeing
reality, but they weren’t seeing reality, right? So here goes Neo
to Plato’s cave– there is Keanu Reeves
with his machine gun– and the guy next to him
says, “It is prophesied that one day a
chosen one among us will break free of
this world and reveal to us the true
nature of reality.” Right? And he says, “No way.” and you
see there the slaves there, right? And what do they see? They see a unicorn
pooping, right? And they said, wow,
unicorns exist. And they defecate
just like we do. And what’s really
going on is there is that naughty philosopher
behind there making little hand signs with his fingers and
projecting these things onto the wall totally fooling
the slaves into believing something that is not real. Right? So the question is,
OK, who are we here? You know, how much can
we see of the world and be comfortable with the
notion of reality, right? So now we go down to
science, and I broke this into three parts. So three kinds of realities. The cosmic reality of the
universe, material reality, what is stuff made of,
and cognitive reality. How do we figure things
out with our minds? OK? So to set the tone,
let me introduce to the wonderful things called
scientific instruments that you all know about, of course, which
are called reality amplifiers. And why do I call them
reality amplifiers? Well, because they
reveal invisible worlds. Stuff that we cannot see with
our eyes and hear, et cetera. And they tell you
things about the world that you didn’t know before. So to give a very specific
example, the microscope. So the microscope was invented
in the late 1600s, right? Now, the conception of what
life is before the microscope and after the microscope is
profoundly different, because before the microscope
living things were things you
could see, right? And after the microscope, you
look into a drop of water, and you see all these
“invisible” creatures what were alive. So all sorts of new questions
like, how small can life be? Is there a limit to how
small it can be, and are these things related to us? And are these things the
things that make us sick? So this completely new
way of thinking about life emerged from that
single instrument. The same, obviously,
with the telescope and with a bunch of
different detectors. I have here on the bottom
two of my favorites. So anybody knows what this is? The Hubble Space
Telescope, right? Which is one of the most
amazing machines ever invented. Picture this, this is a
robot telescope, right? So it’s a robotic telescope
that is orbiting very far away from earth. It is being controlled
by remote control here on earth by
astronomers and technicians and taking pictures that
have never been taken before, and that completely
change the way we understand the universe now. And on the right-hand
side is the Atlas Detector from the Large Hadron
Collider at CERN, which is the machine that
discovered that Higgs, right? And, I don’t know
if you can see this, but there is a
little person here. It is huge. It’s four stories high. It has more steel than the
whole Eiffel Tower in there. OK? And that’s this
giant thing we used to study the smallest
things that exists. You know, the
particles of nature. OK. So cosmic. Let me just– when we’re talking
about the nature of reality and the nature of
truth, just picture the evolution of our
understanding of the universe, right? So when Columbus got not
quite here, but close to here in 1492, what kind of
universe did he believe in? They all lived in an
earth-centered universe. The earth was static,
it didn’t move. There was this kind of
verticality to their existence in which the earth
was the center, then you had all these
planets around it, and afterwards you had this
view of the fixed stars. And outside all of that
was the realm of God. So there was this verticality
in which the universe kind of mirrored what
people believed in. And they guided their
existence based on this, and this influenced not
just the way they lived, but the way they created things. So for example,
Medieval cathedral. They are all vertical, right? They are all very high. Why? Well, because as
you go in there, you want to look up, right? And why? Well, because you want to
commune with God up there, right? So there was, like, this
reproduction of the macro to be human scale
in the cathedrals, and it was mirrored
in their beliefs. So things made sense, right? And this is more or less
what Aristotle proposed way before the Catholic church. But then comes
Copernicus in 1543 and said, sorry folks, the
earth is just another planet. It is nothing special. You know, it’s just
like Jupiter, Saturn. There are eight–
well, at that time there wasn’t eight because
they only knew until Saturn. But there was then Pluto,
and then Pluto is gone. Poor guy, right? Which actually shows how
shifty science is, right? So that’s part of how
things evolve, right? What we call a
planet has changed because we understand planets so
much better than we did before that Pluto really
falls out, in a sense. But so he shifted
the order of things and forced people to
kind of reconsider this whole arrangement
that they had before. And people were very
confused by this, because that centrality
of the earth– which seemed so intuitive, right? You walk out, and
you do see the sky is turning around us, right? I mean, so intuitively
it makes a lot of sense. But science is, in
a way, a mechanism we have to break with all
these intuitions, which are false intuitions, right? So we can see deeper into
the nature of things. And then you cut to
the 20th century, and now our picture
of the universe is completely different, right? This photograph–
which I’m going to repeat because it’s just one
of the most awesome photographs ever taken in history. I’m biased, but it’s true. This is from the
Hubble, and it’s called the Hubble
Deep Field picture. That means the following. They pointed the telescope
at a very narrow piece of sky and collect light for
a very long time, OK? So they can see stuff
that is really far away. So when you look at a picture
like that, you say, oh, yeah. Color. There are some galaxies here. Where’s the Milky Way? If you guys are real smart. AUDIENCE: It’s not in the photo. MARCELO GLEISER: Thank you. Not in this picture, because
to photograph the Milky Way, you have to get out of it. And we can hardly get to Mar. So it’s a long way, folks,
to get out of the Milky Way. But still. So you have galaxies
here, and then you say, oh, what about
these little stars? Well, these are not stars. They are galaxies, too. They’re just
further away, right? So each point of light
here is a galaxy as big as these big spirals,
which are closer. And each one of these galaxies
have about 200 billion, 100 billion stars, just like
our Milky Way does, right? So we live in the Milky
Way– just to give you a little bit of
perspective here– which is this big mass of stars,
about 200 billion of them. The sun is one, and the sun
has eight planets, right? And when you look
at the planets, you say, OK, that’s
not the whole story. Because planets have moons. So Jupiter, for example,
has over 60 moons. So nighttime on
Jupiter must be just awesome to look at these moons. And that tells you that
in our galaxy alone there are trillions
of different worlds. There are trillions of
worlds, and they’re all completely different
from one another. They may be somewhat
similar in some ways, but there are no two
identical worlds. And then you look at this
and say, damn, you know, each each one of these
things is a galaxy. Each one of these galaxies
has these billions of stars. And so the numbers are
ridiculously staggering, right? And how do we gather
information from this? Well, from light, right? And so, for example, when
you look at the moon, you’re seeing the
moon 1.2 seconds ago, because that’s how long light
takes to go from the moon to us. When you’re looking at the
sun, it’s about eight minutes. It takes about eight minutes
for light to travel to us. As you know, the speed
of light is 186,000 miles in a second, which is
another ridiculous number. Basically it means something
like, if you blink your eye, light goes 7 and 1/2
times around the earth. So blink your eyes, 7 and
1/2 times around the earth. And it takes eight minutes for
it to come from the sun to us. And it takes 2 million years for
light to come from the closest this galaxy, which
is Andromeda, to us. So when somebody points a
telescope and sees Andromeda, he or she is seeing Andromeda
as it was 2 million years ago. Meaning when our
ancestors were beginning to go bipedal in Africa, right? That’s when that
light left Andromeda. So what that tells you is
that when you look at the sky, you’re looking at the past. The sky’s our giant time
machine looking at the past. And parenthesis here, actually
you are seeing me in the past as well. You see me about one billionth
of a second ago, right? Because that’s how
long light takes to travel some of this
distance, which basically means that the present does not exist. Now is a cognitive fabrication,
because every information we gather takes time
to get to us, right? And what happens though is
the light is so fast compared to how fast our
brain can process this information that it seems
that everything is integrated into an instant, but it really
is not in an instant, you know? So that’s something to ponder. So what does that tell you? Well, we now know that the
universe is not just this, but is actually expanding. The universe is a
dynamic entity so when people talk about the
expanding universe, they always imagine that
there was this big bang, there was a bomb that exploded
at the beginning of everything and the galaxies are sort
of like shrapnel moving out. That is completely wrong. That is really not what the
expansion of the universe is at all. The expansion of the
universe is really an expansion of the
fabric of space itself. It’s sort of like if
the floor underneath was made of rubber, OK? And I pushed a button here,
and as I pushed the button, it started stretching into
two dimensional directions. You have two directions here. And you’d see everybody moving
away from you, you know? You’d look around and
say, hey, man, look. Everybody’s moving away from me. I am the center of
the universe, right? And the person next
to says, sorry, dude. I am also seeing
everybody moving away from me so I am the center. Because there is no center. This is an expansion
of space itself that is stretching outwards
and the galaxies are basically being taken with, sort of
like a cork floating on water, you know, in a river, right? So that’s really
what’s going on. And so we now know
that this expansion has been going for about 14
billion years– well, 13.8 billion years. Now, you put these
two things together, that light takes time to get to
and that the expansion started in a finite time ago,
and that tells you that light could only travel
so far within that time. And that tells you that
you can only see stuff up to a certain boundary. We call it the horizon. Just sort of like when
you go to the beach, you know, there is
the horizon there where the ocean hits
this sky, right? And you know that the
ocean doesn’t end there, but that’s as far
as you can see. That’s very nice similar. In cosmology we have this light
bubble– the fish in the bowl– and we are inside
this light bubble. And there may be more universe
out there– probably there is. People talk about
multiverses right now, which is something that you
may want to ask me– hint, hint– about. But you cannot see it. So it’s something that
is not just unknown, it’s unknowable, right? Which is like, wow, so
science is telling us there are things which are not
just we will figure them out? We cannot figure them out unless
you come up with a new physics that says that the speed
of light is not the limit, and then, you know, all
bets are off, right? Then you can say anything. When you break the conceptual
structure of something, everything can go. So there is your first
unknowable at the cosmic scale, right? That we really live in
a bubble of information, which is the cosmic horizon,
and we cannot see directly what’s going on out there. OK? OK. Now, just talk about material. So what is the world made of? This stuff, right,
that we are made of? So we are obviously
made of atoms, right? And you know that atoms are
made of protons, electrons, and neutrons. Where would computers be without
the electrons flowing around, right? And that stuff, this
stuff that we are made of, and we have about
92 stable chemical elements that we have found
and that exist, everything else is unstable. And all of these things
came from stars, right? So when you ask where did the
chemistry of the universe come from? Where is the calcium and
the iron that makes me? Where does that stuff come from? It came from stars that
exploded a very long time ago before the solar system formed
in about 4.5 billion years. And so when people
say we are stardust, that is absolutely correct. We really are
literally stardust. And so we are part of this cycle
of creation and destruction where matter becomes recycled
from hydrogen into everything else, you know? One astronomer
once said something that I really like
which is like, people is what happens to hydrogen
when you wait long enough. Which is exactly right. You know, it takes a
long time for hydrogen to be processed into
the heavier elements, and then obviously
for life to develop from that primal,
fundamental substance. But it turns out that, you
know, this stuff– the electrons and protons– make up
5% of the universe. The rest we don’t
know what it is. OK? We know it’s there. It’s sort of like you’re
going to make a cake, and it tells you, look,
there are three ingredients. I know that water is one
of them, and it’s about 5%. And there are two others. And one is about 23
the other is about 73, but I don’t know what they are. So figure it out. How are you going
to make that cake? That is how we are picturing
the cosmos today, you know? So these two items
mystery ingredients are called dark matter
and dark energy. And dark matter is
most probably made of particles that have mass
but have nothing to do with us. Like protons,
electrons, or if you want to go deeper
into particle physics quarks or Higgs or
anything like that. They are something
else, and they sort out float around, gravitationally. They are sort of like a
cloak around the galaxies. And they are in a
factor of one to five. So they are five
times more abundant than our stuff in galaxies. And people have
been trying to catch these guys for
about three decades. And we haven’t been
able to do that. Actually, at Berkley
there is a very big group that has been
trying to get these. And you can’t,
because right now, if dark matter has
really made a particles, they are going through us. You know? They interact so weakly with
us that we don’t even know. Just like there is natural
radioactivity going from the ground going
through you right now. And even more
spectacularly, the sun, to fuse hydrogen
into helium, produces particles called
neutrinos, right? Which are called the
“ghost particles.” They go almost
through everything. And right now, per second, there
are about one trillion– one trillion– neutrinos going
through you per second, right? And we have no idea. So there is this
shower of stuff that is invisible, but
yet very real, right? Anyway, so we don’t know
what the dark matter is yet. There are many possibilities. Fancy names,
supersymmetric particles. But we are not quite sure. And then there is
the big guy, right? The 73%, the dark energy, which
was a complete surprise that came in 1998, which was
one of these discoveries that everybody was
praying to be wrong. Please go away. Because it is so weird
and so mysterious, really. Basically it says not just that
the galaxies are moving away from one another, but about
five billion years ago they start accelerating
away from one another. Sort of like if there is some
kind of repulsive force pushing space apart and taking
these galaxies with, OK? Now, what could do that? Well, there are
candidates, right? Einstein himself put a
term in his equations in 1917 where you can put
a term in the equations that kind of does that. It induces this kind
of stretching of space, it’s called the cosmological
constant, right? But he abandoned it
afterwards saying that was just very ugly stuff. He called it, “my
biggest blunder.” And lo and behold, here the
thing is, again, sort of. Or it could be something else. Something like an aether. I don’t know if you guys
remember, in the 19th century people believed
that light traveled in some sort of
mysterious medium called the aether, right? And everybody believed that. And the aether was
just the weirdest thing you can possibly imagine. Transparent,
weightless, and yet more dense than steel in order
to be able to transfer waves that fast, at the
speed of light. And people believed that
stuff because they could not imagine that a wave could travel
in an empty space, in a vacuum, right? And there goes dark
energy, and it sort of looks like an aether. It is sort of– the same way
the air is everywhere here, there is this thing
across the space that is filling up universe making
it move outwards really fast. So fast that if
nothing reverses this, in about a long time–
50 billion years or so, so way ahead
of time– the universe is going to look completely
different than it does now. So if the astronomers of
50 billion years from now– we can go talk about that later. That’s a whole other talk–
but assuming that they’re there and they are looking
at the universe, they would see something
completely different. They would see almost
complete darkness, because the galaxies
would be just so far out that the light could
not reach us anymore. So they would be sort of in
an island universe, you know? And not be able to see
anything out there. So the way you picture the
universe changes completely as we advance in time. Let me just make a
note of what this is. So this is a self-portrait by
Rembrandt, the Dutch painter. And if you have seen any other
one of his self-portraits, they are always kind of gloomy. But this one he did
when he was young, and it’s called Self-portrait
in the Likeness of Democritus. Now, Democritus
was the second guy that came up with the
notion of atomism, right? That particles are made
of little bits, right? That you can break matter
into fundamental little bits. And he was also called the
Laughing Philosopher, hence the laughing Rembrandt there. And the reason why he was
called the Laughing Philosopher is because he believed
that only if you develop your faculty
of critical thinking and free yourself from slavery–
the slavery of superstitious belief– can you
truly be happy, right? And he, of course, reached his
rational nirvana, in a sense. And he was a happy guy, and
that was his nickname, right? So he was very much
anti-religious belief, you know. And in fact, Lucretius, when
he wrote his famous poem about the atomistic
structure of nature, he would use this image in
exactly in the same way. That to be able to think
critically about reality is your way to break
free of slavery from superstition, right? It’s better not to know
than to live like a fool or be fooled by
belief so to speak. Anyway so of course
when we go and talk about what we understand of
matter now at the quantum level, there are all sorts
of technical questions that we have to ask
which are really strange. So we, here, live in
our “classical” reality where we can touch
things and there is an objective
separation between us and everything else, right? You know you have a
chair outside of you. You’re sitting on it. When you go to
the quantum world, when you look at electrons
and your study them, everything goes down the drain. First because you don’t
see an electron, right? You don’t see a
fundamental particle. What you do see is a click
in a detector, right? Or a little curve in a detector. And that thing appeared there
after being amplified a lot by these photo multipliers. So the electron,
whatever that is, creates some sort of transfer
of energy and momentum. And this thing is
amplified, and then it becomes a click that we see. There is a huge gap between
the reality of that electron and our reality of looking
at data on a computer screen, right? And so there is no immediate
connection with the very small, so to speak. And so when you look
at the equations that describes these
things, and they were all developed to kind of
make sense of data. I mean, people were
making experiments with electrons and
fundamental particles that were very strange and
caused a lot of distress. Including Einstein, right? Because what was apparent
is that you could not have a deterministic way of
thinking about reality anymore. Everything was
really probabilistic. So the equations would say,
look, an electron could be here or could be there with
a certain probability after you measure it. Before, if you
take it literally, the physics of
quantum mechanics, you can’t even say
an electron exists until it interacts
with a detector, right? So that brings this interesting
philosophical question, which is, hey, if the electron only
exists when I interact with it, I am creating reality by the
way I interact with reality. Right? So is reality dependent on us,
like an intelligent observer, or is it just the detector
that is creating the reality? There are all sorts of weird,
complicated philosophical questions that I go into a
lot of detail in the book, I can’t in 40
minutes, obviously. But the interesting point here
is that in quantum physics you have this deep connection
between the way we study reality and the way that reality
manifests itself as opposed to this separation
that you see a rainbow, there is the rainbow. Right? And with the electron, you
can see an electron as a wave or as a particle depending
how you set up the experiment to study an electron. So what is it? Is it a wave? Is it a particle? And this sort of like
an endless debate which has to do with this
interpretation of quantum mechanics. On the other hand, it is
the most successful theory we have in physics, right? It is when you make measurements
with quantum mechanics, you get a precision
to 12 decimal points. There is no theory
that can do that. I mean, gravity sucks compared
to that in terms of precision. And it’s much older
than quantum mechanics. But when we interpret quantum
mechanics, the whole notion of how deep can
you go into reality becomes very convoluted. And essentially also the fact
that there isn’t a fundamental randomness to the way these
particles behave that we cannot predict. So you cannot come up with
a theory that describes if an electron that you’re going
to measure is going to spin this way or that way
when you detect it. So to make it simple, let’s say
the electron can do two things: go counterclockwise
and clockwise, right? So we have 50%
probability of when you detect it being this
way or the other way. And when you detect it,
you’re going to find out. But you cannot do the
theory to predict that. So there is a
fundamental unknowability at the very core of matter. So you go from the edge of the
universe, that we cannot know, to the very core of matter, that
we also cannot know with this precision that we want, right? So these are two sort of
very interesting unknowables. And they don’t seem
to be going away. In particular, in the
case of quantum physics, I was really upset
that they didn’t get the Nobel Prize this year. They gave the
Nobel Prize to guys who developed the LED,
which is fair enough, right? Very important, LEDs, right? But I was rooting for the guys
who made these experiments with the fundamental
questions of quantum physics, in particular can you find
a theory that could describe the electron through
local forces? You know, that could
explain if it’s going to spin this
way or that way. And what they found out, which
is really an amazing thing, is that it’s impossible
to build what we call a “local theory”
of quantum mechanics that explains this
“probability” as the result of some fundamental,
underlying causality, right? So Einstein was wrong. There is no way you can
create a theory that explains this basic,
random behavior at the fundamental
quantum level, which is great for cartography, right? I mean, this is going to be the
essence of quantum computers. So there is this whole big
quantum information theory framework that is emerging
precisely from this. But on the other hand, from
this perspective of how much can we know of the world,
you have a fundamental block right there. And finally I just
wanted to make a point that this is a quote
from Democritus. So he knew all these things,
but he knew also that careful when you talk about truth. And a lot of scientists,
many colleagues of mine, make these big, bold
statements that should not be made in public, you know? Because sometimes they push what
science really is doing or can do way beyond what
we really are doing. And that is a disservice,
I think, to science, especially nowadays when
there is so much criticism to what science can do. You know, you have all the
global climate deniers, right? Who say, oh, these scientists,
they keep changing their minds. No, way, look. They found gravitational
[INAUDIBLE] from the big bang. Right? In March there was is big stuff,
actually here in Stanford, you know? I don’t know if you guys
know the science people like Andrei Linde
and all these guys, like, there would be Nobel
Prizes all over the place. And it’s BS, right? So they had a press conference
before they had a peer review, and that is not what you
should be doing with science. So that just gives
ammunition to all these guys that want to say that we
don’t what we’re doing, right? So the book– the way I’m
bring this together– is really an effort to bring back
this integrity into science and say, look, this
is how we think. This is how scientific
knowledge is constructed. Let’s be very careful about
these big, bold statements about, yeah, we
understand the big bang. We do not understand
the big bang at all. You know, there are all sorts
of fundamental questions we have no clue about. And you have to be very careful,
especially when it’s, like, Stephen Hawking that
says something like this. Anyway, just for the
last couple of minutes, I want to talk
about the last part. the cognitive part, right? And first of all, we have
to say sorry to Descartes because there is
no dualism, right? There is no matter
and soul, right? There is just matter. And the big question in
cognitive neuroscience is exactly how does
the brain engender you with your sense of self, right? So you have 85 billion
neurons, they are all connected– which is about the
same as stars in a galaxy which is kind of a cute
image– and they’re connected to one another by
thousands of synapses, right? And the question is, how is
that giving you your ability to think and to be
yourself every day? You wake up the next morning
and you’re still you, right? There is some sort
of continuity here, and we are all made
of the same stuff, and yet we are so different. So how exactly is that going on? So at the bottom of this debate
is really the question can we build artificial
intelligence machines, right? I mean, is that
something that we can do? And the effort for– the
movement for starting this started at Dartmouth, actually. In 1956 there was
a conference there which started artificial
intelligence communities so to speak, right? With Marvin Minsky
and Claude Shannon and some very smart people. And they said, of
course we can build a machine that can
think like a human. You have to make a distinction
here, one thing is to think. The other thing is to
think like a human, meaning emulate a human brain
through machines. And they were convinced that
was happening real quick, it was just a matter
of a few years. And here we are, right? I mean, you know this
better than I do. We have the fastest
computers now at about 10 to 16 floating
point operations per second. The brain, it is “estimated”–
because we really don’t know exactly– at about 10 to 18. So we’re almost there. And this guy called
Henry Markram, who got the biggest grant in
the history of science for the Human Brain Project
in Europe, 1 billion euros to emulate the human brain
in every possible detail, says– or is convinced
that by 2018 we will have machines
that will get to the 10 to 18 floating point operations. And so if that’s true,
is that all you need? That’s the real fundamental
question, right? Can you just then input
all these 85 billion neurons, connect them? And they even want to do the
flow of neurotransmitters through synapses. You know, they
really want to create some sort of
hydrodynamic code that can mesh with the
sort of binary flip on and off from the neurons. It’s a beautiful,
ambitious project. But the question
is can you do that? And so well, the problem
behind this– and there is a group of philosophers that
have the best name ever, it’s called the new
mysterians, right? And the new mysterians
say, we can’t do that. We cannot understand the
human mind and certainly not to reconstruct it in a machine. You may be able to
reconstruct or create some mind, but not
the human mind. You know? And that’s an important
distinction because we cannot understand consciousness, right? So this is what’s called the
hard problem of consciousness is the notion that one thing
is to look at a painting and monitor all the neurons that
are flashing because you see the painting and you react
to the painting emotionally. The other thing is to understand
the subjective experience of what it means to
look at the painting. They are two different things. There is a disconnect
between the two things. And also another
way of saying it is that when I
look at a painting, and you look at a
painting, we are going to see the
same information. Like, there is a
painting, right? But I’m going to react in
a very different way from, because I have
this consciousness and this subjective experience,
which is not the same as yours. Which a third way of thinking
is that the brain cannot figure itself out, right? And no computer simulation
can simulate itself or include itself in
the simulation, right? And that’s a problem in
computer science, right? I mean, you cannot have a
computer simulation that includes the computer in
the simulation itself. So we have a hard one,
essentially, here, right? And that is the third
dimension, and of course I couldn’t come here
and not mention that this issue of–
the question of living in a simulation
or not is actually a very serious,
complicated question. And we cannot know, right
now, if we are living in a simulation or not, right? There was a paper last
year from some colleagues that they said that if our–
if we are a simulation, and they use a lattice to
simulate reality, which is, say, a square lattice, for
example a cubic lattice, to be three dimensional. Every lattice, when
you simulate something, has a spatial resolution. And in order to probe
very short distances, you can shoot particles
at very high energies to probe these distances
so it is, in principle, possible to tell what would
be the spatial resolution of the lattice that is
simulating us, right? Because the aliens,
or whoever they are, would need to save memory
by doing this lattice. No lattice is
infinitely thin, right? You have to cut off at
some spatial resolution. And so, you know, the
point being here well, but, you know, if
it’s very fine, it’s way beyond
anything that we could create right now in terms
of energy say at the LHC. So we could be fooled, and
it’s a really hard question to answer. Sort of like the Sims, right? Think of the Sims
50 years from now. And we know that we
are playing the Sims, and they have absolutely
no autonomy, right? But 50 years from now, you can
imagine that SIM characters are going to be so developed and
so self-sufficient they’re going to believe that their
autonomous those individuals. So they will believe
that they are real. And, you know, our
grandkids or whatever will be playing with them,
and they aren’t, right? But they don’t know. So the question is can we know? And that is the other
complicated question. So just to wrap up
what is this notion of the island of knowledge then? Well, it’s the way we really
construct scientific knowledge, right? So you have an
island, which is where you put all your knowledge, and
this island can change in time. It can grow, as we
understand things. Sometimes it shrinks,
like the aether, right? And it would be all jagged
because things are not linear. But there is an island that
is on the average growing, and it’s surrounded by this
ocean of the unknown, the stuff that we don’t know
about the world. And the idea then is
there are two ways, right? So the native people would say,
hey, the island of knowledge grows, grows, grows. And eventually there is not
going to be anymore unknown. It’s the end of science. A lot of people
talked about this. And that is complete
nonsense, right? Because, as I try
to explain here, as the island of
knowledge grows so does the shore of our
ignorance, which is the boundary between the
known and the unknown, which basically means this
as we know more, we become equipped
to ask questions that we couldn’t have
contemplated before. Going back to the example
of the microscope, right? Nobody could have
predicted that life would have been that small
before the instrument opened a completely different
reality to people and allowed people to
ask more questions. So the notion of
final truth, which implies complete
knowledge, is absurd because you can never
ask all questions. So if you can’t ask all
questions, how the heck do you know all the answers? Which is a much harder
thing to do, right? So that’s the essential idea. And so you have this
map over there, right? And you have these unknowables
that I mentioned briefly here, right? So to take this
into contect, it’s not like, oh, damn, this is
such a defeatist kind of idea, because it isn’t, really. It’s really about how we make
meaning in the world, right? We are always trying to
go beyond our limits, and that’s exactly
what it should be. And it’s really searching
that makes us matter. It is wanting to know that
gives us value, you know? It’s trying to find the
meaning that gives us value, not necessarily arriving
at the end of everything. And so to conclude, from the
way I picture things here, what we call reality is really
a shifting map of ideas. Because, as you’ve seen, the
fundamental core of reality has changed as our knowledge
of nature has changed in time. And there is no
reason to believe that that’s not going
to continue, right? So we can talk about
what we know now and what we knew
before, but not saying that this is the
end of the story. This is just one beginning, and
there’ll be many, many others. And that’s it. Thank you very much. [APPLAUSE] AUDIENCE: Thank you
for you talk today. I don’t know enough about
theoretical physics. So what are the
major problems there, and if we solve them, what
are the major implications? Like, what could we do
that we cannot do now? MARCELO GLEISER: Well, nobody
can answer that question, right? Because– but I
can tell you what the big problems of physics are. It’s kind of a boring,
but there is dark matter, that I mentioned. You know, what is the
nature of dark matter? What is the nature
of dark energy? Turbulence. We don’t know turbulence or what
causes turbulence in fluids. We don’t know what’s
beyond the Higgs particle. You know, are there any
other particles beyond that? So there are many
fundamental questions. Is there a multiverse? You know, sort of
is our universe the only universe that exists
or are there multiple universes out there with
different laws of nature and ours happens
to be the one that allows for stars
and people to exist? Right? And how can we tell? See, the multiverse has a
very fundamental problem, too, because if it
exists, we can’t know because the other universes
that are part of this multiverse are beyond our
light bubble, which means we can’t get
information from them. And so physics, especially
this sort of out there, more abstract physics, is going
through an interesting time now where some questions
may not be answerable. And yet the ideas are
very nice and compelling. They are interesting, right? But we may never know
if they are true or not. So that to me is
a serious problem that we have to deal with. AUDIENCE: You’re really
curious if you had, say, infinite resources
and infinite time, you presented a tremendous
number of questions. Which question would
you try to answer? MARCELO GLEISER: Right. Well, from a
realistic perspective, like what can we figure out
first, I think dark matter. I think in the next 20
years we’ll figure it out. You know, either it’s there. We’ll find it. Or it’s not there,
and it’s something to do with our
theory of gravity. Because believe it or not, even
though we started with Newton in 1686, it’s the
least understood of all forces of nature. We understand electromagnetic
forces and the weak and strong nuclear forces much better
than we understand gravity. So people are beginning to
say, is gravity even a force? What the heck is going on? You know, because it’s
only attractive, it has– and so I think dark
matter will be the one. But the question that I’m
most fascinated right now with is– which has nothing
to do with this talk, because that’s my research–
I’m using information theory to describe the emergence
of complexity in nature. So how can you quantify,
using information theory, the complexity of objects
from a star to a leaf? And the way you do that
is by– every object can, in principle, be described
by mathematical functions. These mathematical functions
can be decomposed into waves, and you can find out the weight
that each one of these waves would have for that
particular object, and you can extract some
information from that. You know, there’s a whole theory
from Claude Shannon, the guy that was the AI guy, and
I’m very interested in that. Because I think nature
has sort of– you know, we always know the nature
always saves energy, right? I mean everything
that happens in nature uses the least possible
amount of energy. And I think it does the
same with information. All the shapes are
optimized shapes. There is no– so
you can– I’m trying to construct that principle. But it’s very different
from these questions here. Yeah. Thanks. AUDIENCE: I find it hard
to disagree with all this, but I don’t talk to
scientists very much and so I’m wondering
why did you choose to write this book with
this topic right now? Do you think this message
needs to be delivered now? Is it a welcome message or
is it unwelcome for anyone? MARCELO GLEISER: That’s
a very good question. Thanks for asking. I think it’s a very important
time to write this book. I try to hint at this
in some statements I made about, you know,
big, boasting pronouncements by scientists saying that
science is doing this. Science has solved this problem. That’s wrong, and
that is just not true. So I think that what we need
is sort of like to bring back this kind of integrity,
really, to how science is done and what science
can do, you know? So that we protect ourselves
from these attacks. Because science is
under attack, right? I mean 28% percent
of Republicans only believe that the weather is
getting hotter because of– we call it the anthropocene. So that’s really bad. And so we need to do
something about that. And it doesn’t help to
have these pronouncements. That’s one. Second, and I think there
is a big confusion about how science actually works. You know, how do we gather
knowledge about reality? And I think to clarify
these concepts is really important to people. So you know, how
instruments play a fundamental role
in all of that. The limits that they
impose on knowledge. It’s great. Because otherwise
you make science into some kind of
religion, you know, that will solve everything. And it’s just really
not like that. Science is a product
of our creativity, and it’s as wonderful
and fallible as we are. And I’m trying to bring this
sort of sense of grounding. But, yeah. And you ask how
scientists react to it? The humanists,
believe it or not, are taking this much
better than the scientists. Some scientists
say, oh, you know, now you’re basically saying
that we can’t solve everything. It’s like, yeah, so what? You know, be real, right? I mean that’s– we can’t. Period. That doesn’t mean it’s bad. It’s fine. But so be it. Thanks. AUDIENCE: Hey. I had a question, like, if we
know the wave function of all the particles in
the universe, can we determine what’s going to
happen tomorrow, for example? MARCELO GLEISER: We can’t
know the wave function of all the particles
in the universe from a fundamental
principle, which is in order to know that you’d
need to know the position and velocity of all the
particles at the same time, instantaneously. And you just can’t make
that kind of measurement. So you know, it’s
the initial condition to solve this wave equation
that we can’t get, right? So no, we can’t. But you can say that there
is something called the wave function of the
universe, but that’s a much vaguer way of thinking. There was a guy
called Laplace that said that if there was
a supermind– this was in 1810– if there
was a supermind that knew the position and
velocity of all particles at a given moment in time,
you’d just crank, you know, the laws of physics, mechanics,
and you can predict the future. Like, that I’ll be here
talking right now, right? You’d have asked that question. But that is fundamentally
impossible for that reason, and also because of
the indeterminacy in quantum physics. You can’t know the
position and velocity with arbitrary
precision of a particle. But that would be nice. We can’t do it. AUDIENCE: But we assume that
such [INAUDIBLE]– I mean, the wave functions exist so
even though we can’t find out, can we assume that such a wave
function exists and so that our future is already
determined or something? MARCELO GLEISER: I don’t
think so, because, remember, I don’t know if you were
here when I was talking about the randomness at the very
fundamental level of particles? And you can’t get around that. So there is no way
of– and the only way we could do that
is to create what we call a local theory
that explains cause and effect at a point
in space and time. But what people have found
is that the theories can only be non-local. Which is really weird, you know? It has something to
do with entanglement that I didn’t have
time to talk about. And so you’re really stuck. You can believe that
there is something which is an ultimate
reality out there. Probably, right? I mean, the universe
is out there, right? But that doesn’t mean we
can get to it completely. We can only get to it partially. Which is OK. The more you see,
the better it is. AUDIENCE: You mentioned about
consciousness at the end, and you also mentioned
a couple of slides before that that
everything is matter. So I was wondering if
you are aware of models that explain consciousness
as a non-matter entity but still explain everything
else with that kind of a model? I was just curious if you had
exposure to that kind of models and what your
thoughts on that are. MARCELO GLEISER: You mean
models, scientific models? AUDIENCE: Yeah. There are
non-mechanistic models. As you rightly
mentioned, there’s only so much– each tool
has a range, you mentioned. So when you exhaust the tools
that can deal with matter, it doesn’t mean that there’s
not another reality besides that so how do you understand that? MARCELO GLEISER: So
the way– the sort of typical response
to that is something called the binding problem. And the binding problem
is the following. If the brain is matter, right? And something else out there,
call it whatever you want, right? And as this something
else interacts with the matter
of the brain, that means it’s exchanging some
kind of energy and momentum or something, which
is really physical. And so you should be
able to measure that. And the binding
problem is that you don’t know how to bind this
immaterial with the material without producing some effect,
which is a physical affect. And so this is a
fundamental problem. So you can believe things
like that as an assumption, but it would be very hard to
verify this scientifically. So from a scientific
perspective, we go, I don’t know. right? I mean, I hope not. I hope it’s really all matter,
and matter is awesome already. Look at what it does, right? I mean, and the fact that
it’s such a complex problem, the emergence of consciousness,
doesn’t mean that may be unsolvable, doesn’t mean that it
needs to be explained by other means that cannot be
verified scientifically. You know? Unless you’re kind of
integrating in your mind other ways of knowing,
which is fine. I mean, people do that. I’m not Richard Dawkins here. You know, I’m a
[INAUDIBLE] kind of guy. And I’m totally
OK with that, but from a scientific perspective
it’s very hard to justify that. AUDIENCE: Thank you. MARCELO GLEISER: You’re welcome. AUDIENCE: At Google
we are primarily concerned with the universal
access of knowledge. So I think when you talk
about distrust of science in the general
public at some sense, do you think misinformation
is also a contributing factor? And what does the
scientific community use? Like, I believe there will
be some pages somewhere on the internet which say Pluto
is classified as a planet, right? So how do we get people
the most up-to-date scientific information? And, you know,
like, does everybody have to go through reams
of a scientific papers and journals to you know– MARCELO GLEISER: I can
read my blog on NPR. No, I mean, the point is there
is no Google science page yet. Right? Why not? So you should get a
team of consultants from different areas
of science that will give you, like,
a weekly bulletin with critical commentary
that people can go to. Hey, it’s not a bad idea. But the point is there are some
sources that are trustworthy. But I was also mortified when I
saw the “Scientific American,” the cover of
“Scientific American” this month talking about
precisely this measurement of gravitational waves
from the big bang, right? And it makes a big bombastic
statement, and at the very– on the inside, when you turn
the pages– if it’s true. Very tiny, right? Which is a marketing thing. They got to sell
magazines, right? So that’s where the
confusion starts, OK? And that’s where the media,
hey, we want to attract viewers. So the God particle,
with the Higgs particle, has nothing to do with God. Do you guys know the story
behind the God particle? So this guy called
Leon Lederman, who is Nobel Prize winner,
who has been looking for this particle
for 20 years, OK? And he was writing a book
called “The Goddamn Particle” because he couldn’t find it. And his editor said,
take the “damn” out, and you’re going to
sell many more books. And he did. And that is the real
story of the God particle and where it came from, because
I worked with him at Fermilab. So anyways. But people loved this, right? Oh, science and religion
are being– scientists are finding God through the
particle accelerator, right? That’s awesome. So that’s where
things get murky. And, you know, these
blogs– especially when I write about climate
change, you know, at NPR? It’s a war zone. It’s unbelievable how people
get offended by the fact that we’re messing up, you know? And instead of doing
something about it. It’s really remarkable. So there’s no simple
answer to your question. One thing that
possibly could do is that scientists
should go to schools and talk to kids
more than they do. They are very– I mean, how many
kids know scientists, really, in grade school? Or even middle school? And I think that’s
something that we can do that makes a difference. Or the Google Science page. Hey. Thank you. AUDIENCE: Thank you. MARCELO GLEISER: Thanks. [APPLAUSE]


  1. William K Boone Canovas

    October 15, 2014 at 2:01 pm

    Dark Matter is an exotic form of Gravity, which is a bending of the fabric of Space.  Perhaps some millions and/or billions of years ago, at a time where we see the remote galaxies, the bending of Space was different. ¿Does this make any sense?

  2. andrew zuo

    October 15, 2014 at 3:08 pm

    1:03:56 That explains a lot.

  3. Nicholas Garrett

    October 15, 2014 at 4:16 pm

    What kind of eyewear is the introducer wearing? Just curious…

  4. Tony Leonard

    October 16, 2014 at 2:14 am

    Interesting talk.  Looking forward to reading the book in hopes of expanding my shores in this observably real sea of knowledge.  

  5. Marymead2

    October 18, 2014 at 11:44 pm

    This was a fantastic lecture!

  6. Pink Pirulita

    November 8, 2014 at 1:34 am

    Grande Marcelo! I could spend hours listening to him.

  7. modvs1

    January 15, 2015 at 5:02 am

    The poor sod doing the intro is clearly uneasy about the Google pendant they made him wear around his neck.

  8. Gustavo Pavam

    October 4, 2015 at 2:29 am

    Muito bom, fantástico Marcelo Gleiser!!!
    Suas ideias fluem muito bem, conseguindo passar a informação
    de forma bastante clara.
    Sou seu fã!
    BR here! 🙂

  9. Itabar

    October 28, 2015 at 1:55 pm

    Most of his points are relatively rudimentary concepts in the philosophy of science, but he does an excellent job in conveying them publicly. I wish more scientists and science educators were like him.

  10. pascal masi

    November 9, 2015 at 12:42 pm

    Remarkable book and remarkable conference. M. Gleiser has that knack for explaining and sharing science like very few people do. congratulations for this one of kind masterpiece book. I would advise it to anyone interested in searching for reality. No one has to agree to all of it. For instance, the part about AI. Kurzweil's writings deserve a little more in-depth analyses than what the book provides us with. The same applies to neurobiology. So much is going in this field, I would have loved some more in-depth view of S. Deheane's work for instance (on consciousness). Other than that, M. Gleiser is not far away from a Carl Sagan's universalism in terms of sincerity and scope of knowledge.

  11. Vector Shift

    January 14, 2016 at 4:53 pm

    @9:25 "We have a star, about 150 million miles from us." ??????? OOPS!

  12. Vector Shift

    February 26, 2016 at 4:49 am

    Science is THE road to understanding reality. Physics/chemistry/biology etc have made amazing progress since modern science started only about 300 years ago. We are now embarking of studies of consciousness, how our brains work and have given us these miraculous powers. We have just barely begun so see what science will do. In a hundred years when we understand how brains work and supply our consciousness with input that has already launched ships to the moon, all the planets, told us how stars generate enormous energy outputs – how incredibly much more conceptual advance will we make when we can create minds themselves, powers – insights way beyond any current comprehension? The limits of science? Are you kidding? We are way too ignorant, far too unintelligent, too primitive to have anything but nonsense to offer here.

  13. Wayne Brown

    December 12, 2017 at 7:52 pm

    It's about time somebody took "Scientific American" to task. I canceled my subscription recently hand have a drawer full of unread issues. Thanks Marcelo.

  14. Marek Hamsik

    April 9, 2019 at 9:57 am

    Alguém pra dizer que dá orgulho ao Brasil

  15. Mike

    May 1, 2019 at 11:51 pm

    Not only there is some sort of "frontier" which limits us inside a "reality bubble", but also individual intelligence cannot fully understand or access the collective mind, the collective conscience.

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