(intense electronica music) - Welcome Brian, thank you
so much for being here. - Thank you Joe, great to be here. - How are you? How has this crazy pandemic been for you? - Well, I think like everybody
it's been a difficult, trying time, but at
least it seems possible that the end is near. I'm isolated in upstate New
York, in fact as I mentioned before we lost our
electric power last night, in a tremendous windstorm
out here in the middle of nowhere, so I've migrated
to a friend's office here, also in the middle of
nowhere, and hopefully the connection will be stable. - Yeah, let's hope so, and
yeah, there's definitely a feeling of hope, and maybe
even spring in the air. So, yeah, your book Brian,
it's beautifully written, and beautifully crafted,
I love how you use the structure of it to
tell that whole story of the cosmos starting with
the deep physical principles that make order and complexity possible in the universe, and then
you've got this re-flowering of life, consciousness, human achievement, beliefs, art, and then you look
forwards to this long future of the universe, and it gets
quite bleak with the death of literally everything, but
you find meaning there too. So I'm hoping that in our
conversation we can trace that same journey. But first I wanted to
ask you, why did you want to write this book? 'Cause previously you've
written about physics in your books, about string theory, multiple universes, the
nature of space and time, this is much, much bigger, and
you've got not just physics, but you've wrapped in life, meaning, art, basically all of existence, so what motivated you to write
this, to take this approach, and what were you hoping
to achieve with the book? - Well, some would say it's
because I'm getting old. That may be the quickest answer. But the real answer is, my
other books were all about explaining cutting edge ideas,
whether it was string theory, or general relativity,
or things of that sort, quantum mechanics, quantum field theory, trying to explain those
ideas to a general audience, so it was really all about comprehension of the forefront of science. But the thing is even though
I've been fortunate to at times be at the forefront of science, that to me is not the be all and end
all of why I do what I do. The reason I have been drawn to science is because it helps illuminate
the real big questions that we as a species
have been asking since the first member of
our clan looked skyward and tried to make sense of it all. And so, this book really, in some sense, has been growing within me
for the past 30, 40 years, as a professional scientist,
where the work that I do in science has helped inform
my sense of who we are, how we got here, where it's heading, and what it might all
mean, and in this book I try to set down my thoughts
on those big questions. - And you mention at the
beginning of the book the theme of mortality, and
this human fear of death that we have, and that
as a motivation for a lot of what we do, would you
be able to say a little bit about that, and how
that fed into the book? - Yeah, certainly, back,
I think it was the 1980s, although I could be
getting my decades wrong, I encountered a book by Ernest Becker, he won the Pulitzer Prize
in the United States for this book, it is
not widely read today, for whatever reason, I don't know why. When I talk to students at
Columbia they've never heard of that book, but it had
a deep influence on me, and what Becker did in
that book was develop ideas that have really gone
back to some of the early psychoanalysis, Otto
Rank, people of that sort, who wondered, and put forward an argument to the effect that the
reason why we do what we do is we are really the sole
species that has full cognizance of our own mortality. And that recognition
drives us to try to deny our own mortality, to
deny our finite lives, and we do that in a whole
host of different ways. Some soothe that existential
yearning by commitment to a family, or a religion, or a movement, or some leave behind creative
artifacts that extend their presence, albeit in a symbolic way, and that had a deep influence upon me because I began to realize
that I was drawn to physics for exactly the same reason. Physics is that subject which allows us to say sensible things
about the very far future. We can actually glean what it will be like any number of millennia into the future, with a modest set of
assumptions, and that sense of connection to eternity,
was really what I realized was driving me, and it
resonated with what Becker was articulating in that book. - Yeah, it's wonderful
how you link that theme of mortality from the individual
through to the universe. And you take a, you have
a reductionist approach, you talk about how you see
everything in the universe of being composed of particles and forces, but what's really interesting
about it is how you then layer on top of that these
other kinds of stories, so how did you go about doing that? - Yeah, I mean,
reductionism in some circles has a very bad name, a bad reputation. It's sort of the flat
footed scientist approach to the world, if you
imagine that everything is somehow reducible to its
particulate ingredients, and the fundamental laws
that govern how those particulate ingredients behave, and I believe, I feel
strongly that the reason why reductionism has gotten a
really negative reputation is because oftentimes
it has been articulated as an end unto itself. As if once you tell the
reductionist account, you're done. And that I don't subscribe to at all. I do subscribe fully to the
view that at rock bottom reality is made of fundamental ingredients governed by fundamental laws,
but you need to take that as the starting point for a
synthesis where you then build the chemist's story upon that,
you build the biologist's story upon that. And you keep going up layer upon layer of complexity and nuance, you get to the philosopher's account, the neuroscientist's
account, the poet's account, the novelist's account, all
of these accounts matter. They deeply matter,
they are as important as the reductionist account,
because they illuminate different questions, different concerns, which are vital to why we
identify as human beings, and what it means to be a human being. So the reductionist account is vital, it sets the rock bottom foundation, and then as I do in the
book, and as many thinkers across millennia have done,
I try to layer upon that reductionist account the other stories that ultimately lead to I
think a deeper understanding of things that matter to
us, questions of value, and meaning, and purpose. - So we'll get to those
other stories I hope, but let's start then at the beginning with the early universe,
and you talk about two organizing principles,
entropy and evolution. Which helped to bring order and complexity in the universe. So, entropy comes into play first, and this is, it's a popular
concept but it's quite a tricky one, so can you
say a little bit about what entropy is, and why is it important to understand entropy
first, of understanding why the universe is how it is. - Yeah, you're absolutely right, I mean in telling a big
story, from the beginning of time until the end, you
need organizing principles, or else it just becomes a large collection of ideas that don't really piece together in a satisfying manner, and
the organizing principles that I find most useful for
understanding that account are the ones that you mentioned,
entropy and evolution. Entropy as you also note,
Joe, is a very subtle idea. We do have a rigorous
mathematical articulation of what entropy is, but
for much of what I describe in the book, the more rough
and poetic description is pretty good. Entropy is a measure of
the amount of disorder in a physical system. Now that in of itself, is a strange idea, how do you go about measuring disorder in any kind of physical system? And the answer which comes
to us from years of study is that there is a natural
mathematical way of counting the number of rearrangements
of the constituents in a system. A highly ordered system,
you can't rearrange the constituents without changing it. A very messy system,
like a child's bedroom is the canonical example
that we love to use, if it's messy and you go
in there and you rearrange all the books and games and
toys, it'll still look messy. It will not have changed at all, you won't even notice that
the rearrangement took place. So if there are many
rearrangements that go unnoticed, that's a very disordered system. Very few go unnoticed, that's
a highly ordered system. And it turns out, that
nature tends to go from order toward disorder for the
very simple reason that there's so many ways that
you can be disordered, so few ways to be ordered,
so left to its own devices this system will tend
to find itself in one of the disordered configurations. And that is a pattern
that we find not just in kids' bedrooms, but
we find is playing out all across the cosmos. - You used quite a nice
example of a hundred pennies, and so if they're all tails up,
and then you reshuffle them, you're much more likely to get
a 50 50, or closer to that, you're unlikely to go about the other way. - That is the second law of
thermodynamics in action. We tend to go from order to disorder, and with the pennies, an
ordered configuration, as you know, we'd say all tails up, a disordered configuration
is a random mixture of heads and tails. And we all know that you start mixing a collection of pennies,
and they will migrate toward that 50 50 mixture of up
and down heads and tails. - So we can apply that
to the universe and say that we've got this sort
of inextricable increase in entropy as the universe evolves. So, how do we get order and
structure in the universe? - Yeah, that's a deep question, and I don't know that we fully know the answer to that question as yet, but I think we understand
ingredients, vital ingredients, in that answer, and there are two that are worth having in mind. The first is we believe from
our studies of the big bang, and cosmology, and inflationary theory, we believe that the early
universe was a highly ordered state, a very low entropy state. And so much of the order
that we see in the world around us is a remnant of
that orderly beginning. Now you could say, okay,
why was it so ordered back at the big bang? Answer; I don't know, nobody does. But as far as we can tell both through our mathematical investigations,
and our observations, the big bang was a highly
ordered environment. The second ingredient is that
there are natural processes which can yield an overall net increase in entropy, increase in disorder, while at the same time creating
little wonderful pockets of order, and I call this the
entropic two step in the book, it's not a term that many physicists us, but for instance the
force of gravity can take a random mixture of
particles, and cause them all, if there are enough particles,
to fall in on themselves, and build an orderly star. How is that compatible with
the drive toward disorder? Well, in the formation of
the star, a lot of heat and light is emitted to
the wider environment, causing the overall disorder
of the world to go up, even though we get a nice
pocket of order in the process. So that entropic two step,
that entropy can go down here so long as it goes up here,
that is another fundamental reason that we can get orderly
structures in a universe that in aggregate is headed
toward ever greater disorder. - So I love this, it's like a, yeah, like a loophole, you
can't keep complexity down, it's gonna find a way to pop up. So that's giving us the stars, so we don't need to look
for an intelligent designer to explain the starry sky,
we've got this entropic two step which is
allowing these structures to arise, and to evolve, and so. - Actually let me jump
in there just one point, 'cause that's a very
good way of putting it, because normally, when we
encounter orderly structures in the environment, we immediately say, some intelligence must
have been involved, right? You look at a building, you see a book, you see any kind of
orderly structure you say, ah, somebody's been here. Somebody built that. And yet we see these orderly structures, yeah, we see these orderly
structures in space, and some of course say the same thing. There must have been a
guiding intelligence, a higher intelligence, who knows, maybe they're right, but we don't need it, because the laws of
physics and gravity allow those orderly structures to
form without any guidance from the outside. - Yeah, and so, we've got the stars, and then we're creating
chemical elements in the stars, you go through that in the book, so these ingredients that
we're gonna need for life, so that's kind of the next
step then that you talk about is the emergence of life. Could you just take us
through what do we know about how do we get from non-life it life? - So again it's an incomplete story. Biologists the world
over, and generations, have been struggling
to give a full account of how inanimate matter
can ultimately yield living systems, so
unfortunately we can't sit here and give the full account, but
a vital part of that account fits into exactly the
concepts that we have been talking about. Because the fact that you
can build orderly structures, even though the amount
of disorder is going up, that allows orderly structures
like molecules to form, and collections of molecules to form. And there's a version of
evolution by natural selection, which is what most of us learn in school when we talk about living
systems and how they develop over time, but there's
a version of evolution by natural selection that
takes place even before any living systems have
emerged on planet Earth. There's a version that takes place at the level of molecules. Once a molecule learns the trick
of making a copy of itself, of replicating itself, then
those molecules that can copy themselves faster, swifter,
with greater economy, greater stability, those
molecules are gonna come to dominate the environment,
they're gonna be the most fit molecules, and in the
process of making copies, we know that no copying
process is ever 100% accurate, sooner or later there are gonna be errors, or mutations, and if a mutated
molecule is even better at making copies of
itself, then it will come to dominate the environment,
and if that molecule can make copies not just
of itself, but collections of copies of itself, we
therefore see a process where again with no guiding intelligence, molecules can become ever
better at making copies, evermore refined at making
versions of themselves, and collections of
themselves, and in that way we can ultimately, at
least envision a process whereby the molecules
necessary for living systems can coalesce from this primordial
collection of particles, simply by virtue of
this entropic two step, allowing orderly things to form, and this molecular version
of Darwinian ideas. Chemical combat, if you
will, with the winners being those molecules that are best fit. Ultimately yielding the molecules that are necessary for life. - So now yes, we've got this
second organizing principle, this second way to get
that order and complexity into reality, I guess, but
entropy is still important for us as living creatures. We're still, can you
talk a little bit about how we're still living that
entropic loophole if you like. - Well I'd like to think,
and like to say that, I'd much rather like to think
it, maybe say it is better, that we are very much
like the steam engine. I mean the steam engine was
this technological marvel a few hundred years ago,
and when folks were studying the steam engine, they
worried about the fact that you burn fuel to
cause steam in a canister to expand, and for a
piston to go up and down to do useful work, right? That's what a steam engine is. But the scientists in
those early days realized that the steam engine was always wasting some of the fuel by emitting heat directly to the environment, and they
wondered if they could maybe make a steam engine that wouldn't do that. And sooner or later they
realized that you can't avoid the waste heat because the steam engine in order to preserve its inner
order, needs to expel waste, that's how entropy goes
to the wider environment. That's the entropic two step at the level of a steam engine. It burns orderly fuel like
logs, it does some useful work, but it has to emit some entropy, therefore some heat to the wider world. We're just like that, we don't need logs, but we need food, and we use that food, we burn it, in order
to carry out important bodily functions, but at the same time, we have got to emit
entropy to the wider world in order to preserve our inner order, our inner structure, and we
constantly are emitting heat and waste to the environment. And so we dance the entropic two step, for as long as we live. When we stop dancing
the entropic two step, that's when we have reached
the end of our lives. In a way we're gadgets, we're
gadgets that the universe uses to transform some orderly entities and allow some disorder to be
emitted to the wider world. We're a conduit for an
entropy transfer in nature. - Yeah, I'm not sure whether
to find that really wondrous or feel like that's bringing
us down to Earth, but, yeah. - Both I think. - I like that. - I think it's both, because
look how amazing it is that we can do what we do,
and yet in the end of the day we're nothing but living steam engines. - Yeah, well just the complexity,
and the sophistication of the structures that arise
purely from the interplay of these physical forces,
that is really inspiring. So I feel like we've done
some good groundwork now, we've been through these
principles, and so, next, we're moving onto consciousness. So we've got life, and at some point, those living steam engines become aware. Why is consciousness such a tricky topic for science to get its head around? - It's tricky because there
are two kinds of questions of a radically different sort that come into play when you
talk about consciousness. One is can we understand
how a system can acquire complexity, allowing it
to respond to the world in a wide variety of different ways. I mean that's what
conscious beings can do. Inanimate objects, they
don't do very much, conscious beings they respond to the world in a wide variety of behaviors. That kind of question
is not that difficult even though it's a subtle
one, we can imagine a process whereby we could come to
an answer to that question. 'Cause ultimately you're
talking about physical processes yielding physical behaviors,
and that's the kind of arena in which science does a very good job. But there's a parallel
question, which is the deeper question, which is often
called the hard question of consciousness, which is why
in the process of undertaking say the computations
necessary to determine what behavior you're going to respond to, given some kind of stimulus, why is there a concurrent sensation? Why does thought turn into feeling? Why do we have an inner
world in which we can feel, and sense, and have an inner
voice inside our heads? Why do we see the color
red inside of our brains? Why is there a sensation associated with the process of thought? And that is such a deep
and subtle question, because if you think about it, if you are a physicalist as I am, and you do believe that
all we are are collections of particles moving in an
organized, choreographed manner, if those particles
themselves, like electrons, and quarks, if they don't
have any inner worlds, and many of us think that they
don't, how can a lot of them come together and turn the lights on? How can a lot of them
come together and yield the inner world of common experience? And that hard problem is
one that has continued to resist a convincing solution. There are solutions that
people have put forward, but I would say there
is as yet no consensus on how it is that we
generate an inner world of experience from an
outer world of particles that themselves don't
have any inner qualities. - There's science, and especially physics advanced by making measurements,
so you're gathering data and objective evidence, and of
course our inner experience, most of us, would feel
like it isn't like that. We have feelings, the smell
of coffee, the color red, whatever it is, that we would
feel you can't express that in a number, it's not an
objective piece of data. So should maybe we
shouldn't expect physics to be able to explain that? Are they two different things? Or do you, would you? - Well I think you put
your finger on a deep part of the puzzle, it is the
case that our subjective experiences are subjective, right? In fact, none of us can even verify the claim that any of the
other members of our species actually do have inner worlds. I mean I think that you
do, I think that my wife and my kids do, based on their
behaviors and experiences, but I've never been inside their heads, they've never been inside my head, and therefore I can't verify
that the kind of world that takes place between my ears actually takes place between their ears. So that definitely changes the nature of the scientific question. As you're saying we're used
to objective third party data, how does the moon move? How do the stars move? What kind of spectra comes
out of that particular star, and so forth, those
are the kinds of things that anybody with the right
equipment can ascertain the data and set about
trying to explain the data. But when we're talking about inner worlds, I'm the only one that has
access to my inner world, so how are you gonna ever explain it? So you're right, some would say that maybe this is beyond the realm of physics, and certainly famous thinkers,
going back to Descartes, they split up the world into the physical and the non-physical, and some
would suggest that that split is one that we should still respect. Many scientists, and I
count myself among them, do not think that that split is real. I think that split was useful for science, it was very useful for
science, let's put all the mental stuff to the
side and concentrate on the things that we can actually have third party objective measurements about. Newton set us on our way
and we've been sailing ever since, fantastic. But that doesn't mean that the inner world is fundamentally outside
the realm of science. I do think that science
will one day be able to understand conscious
experience as the natural outcome of certain kind of collective
particulate motions that in aggregate yield
that kind of experience. We're not there yet, but I think
that's where we're heading. - So rather than science having to develop new approaches that are more subjective, you think that mathematics
will be able to reach into that realm and explain what's happening? - I would say yes, but I
would also say that I think the borderline between
objective and subjective will shift over time. I think we'll be able
to probe inner worlds in a way that perhaps today
would be considered distasteful, deeply foreign, unfamiliar,
but I think there will come a point where the difference
between the inner world of subjective experience
and the outer world of objective data, that
will become far more blurry than it is today. - Well you tell a story in the book about, well a theoretical story
I guess about imagining a girl, I think was it Mary? Who was colorblind. - It's a famous story, yeah. - Yeah, and so, well you
can tell it better than me. - Well there's a
philosopher, Frank Jackson, a long time ago who put forward
a little thought experiment that has been ricocheting throughout the philosophical community ever since, where he tried to make an argument, just a thought experiment,
where he would try to argue that there has to
be more to consciousness than the physical world
can ever account for. And the way he made this
argument is as follows, he said look, imagine
there's a girl named Mary, and my version of this story
is that she's colorblind, she's never ever seen any color ever. And she desperately wants
to cure her colorblindness, and what she does is she learns everything one could ever know about the brain. Anything that could know about the brain, every detail of molecular motion, every neurological
connection, she goes so, almost infinitely far
beyond what science today has been able to achieve,
in its physical description of the brain, and with that
she is able to understand how to cure her colorblindness,
and she instructs the doctors what to do, and they cure her. Here's the question; the first
day when they're taking off the bandages, and she sees a
red rose for the first time, she finally experiences color, will she learn something new? Now, the stipulation was she already knew everything physical about the brain, and if that experience of
color reveals something new, that would mean there's
something about conscious experience, in this case of color, that transcends physical
knowledge of the workings of the brain. Now I think many of us, our
intuition is when this woman sees red for the first
time, of course she'll learn something new, breathtaking experience of now seeing a color for the first time. And so our intuition, and
this is what Frank Jackson was leveraging, our
intuition is that of course she learns something new
through that experience of color, and therefore he wants to argue there is something beyond the physical in understanding conscious experience. And I think he convinced
many people at first. Certainly when I first read that story I was convinced, and I was
knocked back on my heels, for a few months. I was convinced that I was
wrong in all my thinking that consciousness is nothing
but physical processes, here was an argument, a little story that established that
there's something beyond it. Since then, however,
many people, and I again count myself in that group,
have come to the conclusion that Mary may have a new
experience, she may now be able to describe experiences
in a different way, because now she has a
more direct access to, for instance color,
but she hasn't actually learned something new. She's only found new ways
to describe old knowledge that she actually had through her complete articulation of the workings of the mind, workings of the brain. So this is a story, and
it's still controversial. There are people who are
convinced by Frank Jackson's original argument, in
fact Frank Jackson himself is no longer convinced
of his original argument, he actually later in life flipped around. So, it's an interesting story,
but I think it ultimately is inconclusive as to whether
consciousness is physical. - But I think it is so
interesting in just making clear that distinction there. I think I'm probably still at that point of having that instinctive
feeling that yes, there would be something
new, and I would love it if people watching could
maybe put in the chat, I don't know if it'd be
interesting to get a spread of opinion of whether people
think that there is something about experiencing red
that would be new to Mary when she actually finally
sees it for the first time. - And there are researchers
who still, I mean, David Chalmers, a famous
philosopher, thinker, about these ideas, he as
far as I can tell based on one of his more recent books
is, he's still convinced that that argument of Frank
Jackson, and the story of Mary, does establish
that there's something more to consicousness than physics
and physical reasoning would ever reveal, so yes, that
intuition and that response is completely understandable,
and there's some who still argue that perspective strongly. - So he's written about a
kind of pan psychism I guess, some sort of proto-consicousness
that all particles are imbued with from the
beginning, so we no longer have to explain how consicousness
popped out of nowhere, but it's just something
that's been refined and evolved as our physical bodies have. And I guess he would say that that is all within the laws of physics,
it doesn't go against any of the science. - Totally, totally, he would say, look, if you're struggling to
understand how mindless, thoughtless, emotionless
particles can yield mind, and thought, and emotion, the answer is the
particles are not mindless, thoughtless, emotionless. The particles themselves
do have a little bit of thought, a little bit of mind, a little bit of emotion that he calls a proto-consicousness quality. And then he simply
says, hey, when you have a lot of particles, there are
little bits of consicousness, their proto-consicousness
qualities aggregate, and yield the conscious
experience that large collections of particles inside a
human brain can yield. And so yes, his view is that he's tried every other solution to the
problem of the hard conscious, hard problem of consicousness,
and the only solution that he sees left standing is to change the nature of particles themselves. Look, that's a radical idea,
I think it's really worthy of thinking about, and
you're right, in principle it doesn't step outside of physics. We simply have to say that
the properties of particles, sure, their mass, we've spoken about that for a long time, their electric charge, their weak nuclear charge, their strong nuclear, those we understand using the standard model
of particle physics, and he would say there's
something else that you need to add to the list of
qualities, of particles. This proto-conscious quality. And in principle you
might be able to quantify with numbers, you might have
equations that talk about that quality of particles,
nobody has these numbers or equations as yet, but that in principle is where that line of
reasoning could lead. - So I guess there's no
reason, fundamental reason, really why all of the
properties that we choose to, we measure the properties of
particles that we can measure, and I guess there's no reason
why there couldn't be other properties that we can't measure. - Yeah, I'd even go further than that. - If we are able to measure everything. - No I totally agree with that,
I'll go even further though because if you ask me, what is mass? What is electric charge? I'm hard pressed to give
you a fundamental answer to that very basic question. All I can do is I can
say I know how to measure those features, and I
know how to determine what those features
entail about the behavior of the particles. I know how massive
particles behave compared to lighter particles, I know
how particles with a lot of electric charge behave
compared to particles that have less electric charge, and so I don't know what
mass is, I don't know what charge is, beyond
that kind of description, and therefore when it comes
to this proto-conscious quality, maybe we won't
ever be able to say what it really is, that may be
forever beyond our reach, but maybe one day,
according to David Chalmers and others who think this
way, we'll be able to describe how proto-conscious qualities behave, and how it is that when they come together they yield this inner
sensation of thought. That might be the best
that we can ever do. - I can feel my neurons firing
as you're talking about it. So with consicousness you
admit some uncertainty at least in terms of what our
final explanation might be, but then you move onto free will, kind of even thornier issue perhaps, and do we have control
over our own actions, and decisions, and there it
seems like you allow less uncertainty, if you'd like
to talk about what you think physics means for the
existence of free will. - Yeah, I mean I do in
the book, and when I speak about this, talk about
it somewhat forcefully from a certain perspective. I do qualify my forceful
articulation of my views on free will with the understanding
that if David Chalmers' ideas, perhaps are right,
and consicousness is just completely different from
our intuition about how it works, perhaps that
would have an impact, I don't even know that it would, but my view is indeed that we
do not have the traditional intuitive notion of free will. The intuitive traditional
notion is that we are the ultimate authors of
our actions, we are where the buck truly stops, when
it comes to the decisions we make, the actions
we take, and that idea is deeply incompatible
with the understanding that we are large aggregates of particles governed by physical law. Every thought we take,
every decision we make, ultimately in the reductionist language, is nothing but our particles
moving one way or another, and everything we know attests to the fact that we cannot intercede
in that physical unfolding. We have no affect on
that physical unfolding, that physical unfolding
is fully determined by the initial conditions,
and the laws of physics. And therefore the idea
that we are ultimately where those behaviors,
thoughts, decisions come from, is deeply incompatible with all we know about the physical universe. - So this is quite a big
thing that you're saying here, probably, for most humans
who are listening to that. The idea that we have absolutely no say in what's going on, is
gonna be counterintuitive and unpalatable, and against
a lot of what a lot of people feel is central to what
it means to be human. So could you lay out a little
bit more what gives you that confidence, what
is it about the physics and the results that
we've had that tells us, that closes the door for
this to be able to happen? - Well, I mean the confidence, which again I need to emphasize, is mitigated by my full happiness to admit that since we don't fully
understand what consicousness is one has to be somewhat
humble in one's statement. But under the assumption that
consicousness is something that derives from the
physical, that's the only assumption that I'm gonna
make, with that assumption I am fully confident of the conclusion that I reach because my 30, 40 years as a particle physicist, my recognition of what our forebears and
our colleagues have done across centuries has all led to the view that the physical universe is lawful, physical universe is lawful, that's all that one needs,
because once you admit that the physical universe is lawful, it follows patterns,
that can be, say at least in our era, articulated in
the language of mathematics, once you stipulate that,
and everything we know points in that direction so fully, then there's no opportunity for any of us to intercede in that lawful progression. The laws don't chug along
for some time and then say, oh, hang on laws, wait for
Brian to make a decision, hang on, hang on, he
hasn't yet decided, wait, okay he's decided, now laws,
take over and keep going from there, that's not how the universe as we understand it, unfolds. The laws are always in
control, the laws are never not in control, the laws have
no opportunity for any other kind of influence that's not
part of the lawful progression. And therefore once you have that view, and you realize that our
brains, if under the assumption that consicousness is nothing
but physics acting itself out on the particles of
nature, there's no opportunity for us to have the kind
of freedom that many of us intuitively think that we do. - And in the book you go through also how even in a quantum,
probabilistic system, like some people would say,
is there room for some nudging there, but you say no,
that's not the case. - Yeah, there's a long
tradition of people looking to quantum mechanics as the
source of human freedom, the idea being Newtonian,
classical physics, has a certain kind of rigidity. Tell me how the world is
now, and Newton tells you how it will be tomorrow. With that sort of ridged progression, it seems obvious that
we don't have free will, there's no freedom in that story. Quantum mechanics comes
along and says, well hang on, that's not actually how the world works. Tell me how things are
today, and I will tell you the probability of how
they will be tomorrow, that's the quantum paradigm. And within that probability, there are now many possible outcomes. And so people say, aha,
that's where freedom is. We choose which outcome of
the many that are allowed by quantum mechanics, but that's nonsense, we don't pick it. It's certainly a probabilistic theory, but the progression is
again fully determined, as far as we understand
it, by the lawful qualities of the world. The fact that there's
probabilities involved, that may at first sight
give an opportunity, but when you think about it,
it's completely irrelevant. If I told you that your
behaviors were determined by a flip of a coin, would
that make you feel better in terms of the control that you have? No; the fact that it's
probabilistic doesn't add anything to it, because
you are not involved in the decision of what transpires. And you can't be because
if you did have that kind of role, the probabilistic predictions of quantum mechanics would
not agree with the data. So probabilities might at
first sight seem to open the door, but when you
think about it more fully you can shut that door really tightly. - I'm gonna keep looking for a little bit of wriggle room here, so this
is probably a stupid question, but presumably all the physics experiments are done on inanimate matter. Do we know whether all
of those predictions would still hold true
on a conscious frame? Could you, you talked
about the entropic two step at the beginning, could
you have a quantum two step where you can nudge a probability here, and get something back over there? - You're absolutely right,
that is a great question to ask because it is not the
case that we can make the kinds of predictions
that we make for individual electrons, or hydrogen
atoms, where we can test those predictions to fantastic accuracy. Nobody can do those kinds of calculations for a living system. I can't calculate what you're
gonna have for breakfast tomorrow and then compare
it, or the probability of what you're gonna have
for breakfast tomorrow, and then compare it
with actually the data. Because the computations are too complex, they're too difficult. And so you might say,
maybe somewhere in there, that's where freedom emerges. And it's not that I can come
with an airtight argument where I can show you the data, establishing that that view is incorrect, but I can rely upon a few
hundred years of experiment that seems to deeply
suggest that having large collections of particles
may make the calculations more difficult, but it doesn't
introduce anything new. There are no physical laws
that somehow come to bear that were not relevant
when you're talking about the basic ingredients themselves. So, I can't give you a slam dunk argument, but I can say that there's
nothing that we've ever found, and everything that we have found, points to the conclusion
that I'm describing. Could it be wrong? Yes; it could be wrong, but
nothing even remotely suggests from our understanding
of the physical universe that that's the case. - Okay, well fortunately,
you have a different kind of freedom to offer us. - Yeah, I'm glad you bring that up, because I do feel strongly that we're too attached
to the kind of freedom that our intuition suggests that we have. I believe that the reason
we have this intuition, that we are the ultimate authors, we're the place where the
decisions really happen, from an evolutionary
perspective, that must have provided us a leg up on the competition. And therefore this way of
thinking about the world became ingrained in our
perspective on reality. But we all know that there are many things that are in our intuition
that are deeply wrong. I think that this table
is solid in front of me, but we know that it's not solid. Quantum mechanics, and our
understanding of the world allows us to recognize that
it's mostly empty space. So intuition can be deeply misleading. There's another version of
human freedom that deviates from our intuition, that
I think is really worthy of focusing upon, which is this; how do we differ from the kinds of things that we don't feel have free will? How do we differ from say, a rock? Well we differ because
our internal organization that comes from evolution
by natural selection, is so much more sophisticated
than the internal organization of a rock, and that allows
us to do things that simply are not available to the rock. A rock just sits there, you look at it, you touch it, you talk to
it, it doesn't do anything. You kick it, it rolls, and
it doesn't do something someplace else, we can do so much. We can respond with such a
wide behavioral repertoire that is intrinsic to what it
means to be a human being. See, our freedom in my
view is not to transcend physical law, we don't have
that freedom, nothing does, our freedom instead is to be
liberated from the constrained behavior that has long since governed the inanimate world of rocks
and other inanimate structures. That's what we should focus upon. And that's why behavioral
repertoire is responsible for everything that we
as a species have done. That's our freedom, and
that's the freedom that we actually have, and that's the
freedom we should focus upon. - And you go on in the next
few chapters of the book to explore what that
freedom has unleashed, and enabled us to achieve. First of all, stories, you're very attached it to stories. Could you say a little
bit about why stories are important to us, and why
do we tell fictional stories? - Yes, so you're absolutely
right, once we realize that we have this kind of
freedom, this wide range of behaviors, and wide range of thoughts, and wide range of responses,
you then are naturally led to wonder, is there some
pattern in those behaviors? And one of the dominant
patterns that we have learned from looking at our evolutionary past, is that since the earliest
days we have told stories. We have concocted narratives,
and the reason for this, again, is somewhat controversial, but the explanation that
I find most pleasing, and most satisfying,
is one that comes again from evolution, but it
comes from evolutionary psychologists, who have
realized that our behaviors, not just our physical
form, but our behaviors to some extent, you can overdo
it, and they often caution don't go too far with
this kind of reasoning, but our behaviors have
been governed by survival in the ancestral world. Those behaviors that allowed us to cope with the challenges of the
past, are the kinds of behaviors that became intrinsic
to our molecular makeup. And among those behaviors is storytelling because storytelling allows
us, in a very safe way, to experience things that if
we were actually to experience in the real world could
be quite dangerous. And that then prepares us, as a species and as individuals, for
challenges in the world without having to suffer
the danger of encountering those challenges in a first hand manner. We can imagine them, we
can think them through, we can imagine battles,
we can imagine challenging encounters with wild animals, we can imagine very dangerous situations, and by thinking them through,
when we actually happen to encounter those situations,
to deal with them in a far better manner than
we otherwise would have. It's an explanation that some have called
- Like conflict and resolution in our stories? - Yeah, that's right, it's
like a flight simulator of the mind. I mean, how does a pilot.
- I love that analogy. - Yeah, train to fly? They have these flight simulators; why? You don't wanna send the pilot out there into the thunderstorm,
before they've actually experienced it in a safe way. Similarly, stories are
the flight simulator of the mind, allowing us
to experience those things that would be dangerous to
encounter for the first time, but by training through
story we can deal with them in a far more effective manner. - And then we have mythical
and religious stories, and you seem, for a reductionist, a bit more accepting
of religion than a lot of scientists might be. So can you say a bit
about what you would see as the value of religion? - Yeah, very much so. I mean, look, many of my colleagues, many of them well known,
no doubt, to the audience that's listening to this conversation, would be all too happy to simply see religion go away, to see it wiped off the face of the Earth, and
I don't see it that way at all, I see religion
as the natural outgrowth of the storytelling instinct that has been with us from way back when. Allowing those stories to
cope with, as we started off in this conversation, one
of the most devastating recognitions that we as a species have had which is, we're mortal,
we're all gonna die. Our presence on this Earth is finite. And I think it was Stephen
Jay Gould who said, all religions begin with
an awareness of death. In one way or another the
world's religions exist to help human beings cope
with this deep recognition of our own mortality. And it's certainly the
case that as society, and as science develops
further, thinking of religion as an explanation for
things in the external, objectively available data,
that will be an ever poor guide to understanding the world. Don't get me wrong, I'm
not saying that the world was created in seven
days, science is the tool that we should use for understanding
the origin of the Earth and the origin of the
cosmos, and so forth, but religion can for some be
a powerful and poetic tool for understanding their own inner world, their own coping mechanism
for navigating a world in which they know that their own presence will be finite. And William James, a great
American scientist psychologist back in the early 1900s, he wrote a book called The Varieties
of Religious Experience that I think every human
being who thinks about these things should read. - Oh, that's a wonderful book. - His point in that book is, his point in that book, at least in part, was to recognize the different
ways that people have religion as part of their
worldview, and to recognize that if your only knowledge of
the world comes from science describing this external
environment that we are immersed within, you can lose the poetry of inner experience, and that
poetry of inner experience for many is deeply entwined
with a spiritual sense, a religious sense. And so to try to eliminate
that would be to eliminate a vital part of the human story. - And you talk in the
book quite movingly about when your father died, and how you found certain traditions, religious
traditions comforting then, and you talked about the
history and the connection, and the heritage that comes
with some of these practices. - Yeah, I think that's
a deep part of it too. I mean, many of the world's
religions, and I emphasize this in the book, the obvious
fact is many of them are old. And that venerable quality
allows us in the modern era to feel connected to a
long lineage of individuals in our past that had to
cope with the same kinds of very human, all too
human challenges that we do. And yeah, when my dad
died, I'm not religious, I don't go to temple, I don't
follow any of the rituals in a yearly, annual manner,
but when my dad died a minion of observant Jews
came to our apartment, and they cited the Cottage
Prayer, and I had no idea what it meant, but it
was deeply comforting. It was deeply comforting
because I felt like I was being embraced by a
5,000 year old tradition that had coped with this all too natural and all too real part of human experience. So it didn't change my scientific outlook, but it did enrich my inner
life, and my inner capacity to deal with one of life's passages. - And then let's onto art. So what are some of the ideas around how art may have arisen? And I'm really hoping that you're going to mention cheesecake. - I'm sorry, what was the, oh, cheesecake. (laughing) - Yeah, well, again, it's
a controversial subject, which all of these are, which
makes this whole journey I think that much more interesting. But there are some who argue, and I feel strongly that
this is a worthy explanation of where our artistic practices come from, art is a kind of playground of the mind. I mean, ornithologists have
long known that animals engage in play, in order
that they then can deal with the challenges of their
environment more effectively. So play fighting, and
play battles, allow them when they encounter the
real ones, to do better and therefore it has a evolutionary role. Art in many ways can be viewed
as a playground of the mind, where the mind is given
free reign to go beyond the constraints of the physical world, to imagine things that are not
realizable in the real world, allowing a kind of ingenuity,
and experimentation, and innovative exploration
to be part of how we engage with the challenges that we encounter. And I full well believe that
that all too human quality is what helped us to prevail. I mean, if there were another species, another humanoid species,
that didn't practice art, was not interested,
that's a waste of time. Why would I spend my time sculpting, or painting, or composing,
when I can get more fruit and vegetables? When I can sharpen more spears to get more deer and antelope? Of course I should do
that, one would think. But I think that that
version, that humanoid species would not prevail against us. Because when we encounter challenges that require creativity,
require ingenuity, it's our willingness to go
beyond the obvious things in the world around us, the
choices that would seemingly be the right ones, it's our willingness to go against that grain that
has allowed us to prevail. And that ultimately, I
and many others think, is the origin of why we compose. Why we sing, why we dance, why we paint, why we sculpt, from cave paintings to Beethoven's 9th Symphony. - It's almost like blue skies research, that you have to just be going out there and asking questions and
then being creative, and not. - That is a version of the same story. Many people look at science
as something that is all about just following a certain
set of prescribed rules, the scientific method is
often what we teach kids, and sure there's something to that, but every time I hear
about the scientific method it makes my heart sink. Because we scientists, we don't practice the scientific method in
any rigid formulation, we allow our creative
imaginings to take us to unexpected places, and
99% of the time it's wrong, it's not relevant to what we're doing, but 1% maybe, it's right. And that's what gives rise to Einstein's general relativity, that's what give rise to quantum mechanics. The ability for the mind to
go to these unexpected places that an algorithm like
the scientific method would never suggest. - Yeah, you said that, was it Einstein? That you said the he thought in music. - That was his own description, yeah, he said he rarely thinks in words, he often thinks in music,
what a beautiful idea that is, that he's just composing these, these melodies, that
ultimately are articulated in a mathematical language. - So we might have to come
back to the cheesecake in the Q and A, because
I wanted to just move on to what was one of my
favorite bits of the book, well there were lots, but
you talk about experiences, some of them artistic, but
other kinds of experiences as well that you said
can't be put into words, that had a meaning that was beyond words, and perhaps are meaningful almost because they couldn't be explained
rationally, or logically. I wondered if you could say
a little bit about that. - Yeah, well, articulation, language, language emerged for a particular purpose. Again even that's
controversial, I described some of the ideas in the book as well. But ideas of Daniel Dore
have had a deep influence on me that languages
developed in order that an individual can guide the imagination of another individual,
allow them to experience things through words that they themselves have never experienced in the real world. You can see there's a lot of advantage for groups of individuals
to be able to do that with each other. But language itself therefore was selected for a very specific kind
of purpose, and we have broadened out that purpose quite widely, but why would one think
that all human experience would naturally be something
that could be described in this one particular mode? That could be absorbed through
this one particular mode of spoken or written language? And I don't think that
spoken or written language does exhaust the capacities
of human experience, and I certainly have had experiences, and I describe some in
the book, that I don't try to put into words, I
don't know how to put them into words, and I wouldn't
attempt to put them into words because I'm not looking for that mode of description. There are some things that
one has an experience of in the world, for me it was
at times on a mountaintop, with a survival course that I was on, seeing the northern lights. Another experience that
I describe in the book is one in which I
accidentally ran over a dog with a car, and I was with
that dog in its final moments. These kinds of experiences,
and a wealth of others, for me, I feel them, I grasp
them, I understand them, I've integrated them into my worldview, but I consider them beyond language. - It does seem a really
interesting tension, because you have this
reductionist approach, and everything is particles and forces, and yet here you're saying
that there are these experiences that can't
be explained rationally, but they have a meaning that is a bit more than that, almost. - Good, good, well you
see because language and rationality I see
as physical phenomenon that are carried out
by this particular kind of collection of particles. Why would one think that
this particular collection of particles, and what
it can do, and the modes by which it communicates,
why would that be exhaustive? It's not; and therefore
this collection of particles can take in experiences,
and process experiences, in a manner that's parallel to the rational, parallel to the articulable, parallel to the narratable,
but not necessarily subsumed by those qualities. And therefore you can feel
something without having to articulate it. - So what about mathematics then? Would we expect mathematics
to be exhaustive? - Yeah, I do, I do think, well see I view mathematics,
and I've gone back and forth on this over the course
of my own career and life, but I for a long time now have stabilized on thinking of math as a language. The old question, is math
invented, or discovered? To me, I think that math is invented. We encounter patterns in the world, and we invented a language
called mathematics, which is really good at
describing those patterns, and using those patterns to
make predictions for other patterns that we should henceforth see. But to me, math is just a
language of human invention and therefore has its own limitations. - Okay, well we had better move on in time and start getting towards the future, 'cause we are running out of our own time, so yeah, you move on
way, way beyond humanity, beyond our species, beyond the planet, to look incredibly far in
the future at what we can say about what might happen,
and you have this wonderful metaphor of the Empire State Building, so I wondered if you
could just explain that, and tell us a little bit
about what might happen as we go forwards in time. - Yeah, certainly, I mean as you say the narrative arch of
the book is to start at the beginning, the big
bang, find the organizing principles that give rise
to complex structures like human beings, that give
rise to conscious experience, that give rise to language,
that give rise to religion, give rise to art, but
then I pivot from today and use those principles
to look arbitrarily far into the future, and this
Empire State Building metaphor I think is a nice one. What I do is, I say
imagine that each floor of the Empire State Building
represents a duration 10 times that of the previous floor. So the ground floor, one
year, next floor, 10, next floor 100, and so forth, so it's a exponential scale up the floors of the Empire State Building,
and in that approach, everything from the big bang until today takes us to just about the 10th floor, but the Empire State Building
goes to up to 102 floors, and I take the reader in
some sense floor by floor. We don't stop at every floor, thankfully, but we go floor by floor
to see what the universe would be like exponentially
far into the future. I mean, we can hit some
highlights if you want, if that would be a useful thing to do. - Yes please. - Sure, so at, we all know
that the sun is gonna swell and engulf the inner planets,
that's relatively soon on these scales, that's
between floor 10 and 11, by floor 12 the ever quickening expansion of space will drive distant
galaxies away faster than the speed of light, and
so we'll be floating in a sea of darkness by the 12th floor. By the 14th floor, most stars
use up their nuclear fuel, they fade to black. By floor 20, if the
Earth wasn't swallowed up by the swelling sun, back around floor 11, it will no spiral into the dead sun, having lost energy through
gravitational radiation. By floor 30, most stars
fall into the galaxy's central black hole. By floor 38 we believe
it's likely that protons, the heart of matter, they
will likely disintegrate, so all material structure
will disintegrate into a bath of particles,
and then roughly speaking, between floors 68 and the
peak, black holes themselves will evaporate, Stephen Hawking taught us that they give off a
gentle kind of radiation that increases in intensity,
during the duration of their lives, and
ultimately they give off all of their mass through this radiation. And so by about the peak of
the Empire State Building, the only thing left is a
quiet bath of particles floating through the darkness. That's a rough summary
from here until eternity. - So you take us all the way to oblivion, and there are some kind
of weird, and wonderful exceptions that we don't
have time right now to go into detail in, but
people will have to read the book for that. But yeah, so we're, yeah, we're in oblivion,
darkness, nothing, everything's gone, it's
not just us as individuals, the species is gone, the planet's gone, basically every structure
in the universe has gone. Thoughts has gone, so, how did you respond to this knowledge, and how have you dealt with
that and found meaning in that? - Yeah, I mean certainly
when I first encountered these ideas, which, it was
over a long period of time, physicists tend not to focus on the story that we've been telling
here, they tend to focus on one era, or another. They don't usually look
at the whole thing. When I first encountered these ideas, I found it deeply disquieting. Definitely sent me into a
dark place for a little while. This idea that everything we care about is gonna disintegrate,
everything that we think matters, in the grand scheme of
things, will dissolve away. But over time I've come
to a different place with these ideas, a recognition
of how utterly wondrous it is that collections of particles, governed by the physical laws,
can somehow come together, and yield conscious
beings capable of doing what we're doing, capable
of thought and reflection, capable of illuminating
mystery as we have done, capable of creating beauty,
which we have certainly done. Capable of experiencing
wonder, and when you have that recognition, and you deeply take it in, my experience has been that it
yields a sense of gratitude. And a sense of reverence
for being here at all, and that deep gratitude and
reverence is not diminished by the fact that it all
dissolves, it's a gratitude and reverence that
persists however fleeting human experience may be. (audience applauding)
