Transcription
Maybe the Big Bang is an interesting
event, but not the beginning of time.
This reality might be one of many.
String theory does have the capacity to
describe the world as we know it.
Principle is the idea that we could be
visited by aliens, a crazy idea. No,
it's not crazy. If they're a billion
years ahead of us, they're not building
spaceships and coming to planet Earth
because they don't care about us. Maybe
the particles do have some kind of
version of consciousness, some kind of
protoconciousness, a little bit of
consciousness in the electron, in the
quark, in the protons. Where does it
come from?
What happened before the big bang? No
one knows what happened before the big
bang. No one even knows if the concept
of before is relevant when you apply it
to the big bang. I mean, before
obviously is relevant to what was I
doing before I got here today or what
was I doing before the election, you
know, a couple weeks ago. All those
notions of before make sense. But the
big bang may be the moment where time
itself began. And if that's the case, to
talk about before the big bang would be
to talk about a time when there was no
time. And so it would be an incoherent
notion. That's one possibility. The
other possibility is sure maybe the big
bang is an interesting event but not the
beginning of time not the beginning of
everything. Maybe the big bang is an
interesting realm in which the universe
swelled rapidly. That's what we mean by
the big bang. But maybe the universe
existed before that. Maybe there were
other big bangs that happened before
that. Maybe there's a whole prehistory
leading up to the event that we call the
big bang. As of today, nobody knows
which or if any of these perspectives is
correct. In our theories, mathematical
theories, we always assume that there is
time from the get-go. We don't even know
how to formulate physical laws without
assuming that time exists. So our
mathematics gives us no insight into
whether there is an origin to time or
whether there might even be a realm
where there is no time, there is no
space and only when the ingredients in
that realm that we can't fully describe.
When they arrange themselves correctly,
then space and time as we know them
emerge. We don't know if that's a
sensible way of thinking about reality,
but it certainly is a compelling one to
imagine that as a possibility. Time
could certainly be a human construct.
Time could be something that we impose
on the external world because it allows
us to organize events. And when we can
organize events, we can find coherence.
We can find patterns. We can describe it
all mathematically. But sure, can I
imagine that we encounter some alien
civilization in the far future and their
conception of reality doesn't involve
time at all or maybe as fundamentally as
our conception does. That they organize
events according to a completely
different framework that does not
involve moment after moment after
moment. that their experience is not
felt as moment after moment after moment
as our experience is. Can I imagine
that? Yeah, I can. Did universe begin
from something small like a pin? Sure.
In the conventional approach to the big
bang which often goes under the name of
inflationary cosmology, we imagine that
there was a little tiny pike sized part
of space that was filled with a certain
kind of cosmic fuel. It's called the
inflaton field. Name doesn't matter, but
this fuel gives rise to powerful
repulsive gravity. That's a weird idea.
We are used to gravity that's
attractive. You drop something, it falls
to the earth because the earth and the
object attract one another. We have
never directly experienced repulsive
gravity. But Einstein's equations from
general relativity say that it is real,
that it does exist. And so imagine you
have a little pe like shape that's
filled with this fuel that gives rise to
repulsive
gravity causing it to rapidly swell, to
blow apart. That's what we think may
have been the big bang. And so yes,
everything would have started from an
incredibly small but dense, highly
energetic starting point that gave rise
to the big bang creating cosmic web.
Cosmic web in terms of the galactic
structures in the universe. Absolutely.
So we can use the inflationary theory
together with our understanding of the
electromagnetic force and the nuclear
forces. We can use powerful computers to
simulate what the universe will look
like after this rapid swelling. And we
understand the formation of stars and
galaxies. Not in every detail by any
means, but we can understand the
processes well enough to get a sense of
what the universe should look like on
its largest of scales. And amazingly,
while we don't have all the details,
what our computers predict is pretty
close into what we see. And that's an
amazing achievement. Cosmological
landscape changed your life? Well, all
of these ideas have changed my life
because my perspective is guided by my
understanding of reality. And so as I
learned quantum mechanics, my sense of
reality began to shift. And so I and my
engagement with the world began to
shift. When I learned the general theory
of relativity, the same thing happened.
These were wondrous educational moments
for me. It wasn't just learning about
warps and curves in the fabric of space.
I felt like I knew the universe better.
I understood it better. I could engage
with it more richly. And sure, these
more speculative ideas that there might
be other universes out there, does that
change my view? It enriches it as a real
possibility that this reality might be
one of many. How could knowledge of
these ideas not then backreact on your
own view of who you are and how you fit
in? It does. Infinitive universes. Do
you believe that it could exist? I think
the possibility of infinite universes
is an idea worth having in your toolkit
because a it naturally emerges from a
variety of ideas from the inflationary
theory to the many worlds interpretation
of quantum mechanics. So it may be true
and if it is true it completely changes
the landscape of reality. And so for me
to sit here and imagine there might be a
copy of me out there in the cosmos
infinite copy of us. If the universe is
infinitely big then you can pretty much
prove mathematically that there'd be
infinite copies of us out there one
after another after another. Sometimes
having exactly the same conversations
sometimes having slightly different
conversations. That's a crazy idea. But
is it the idea or theory, real theory?
Um, can we talk about it seriously under
physics? You can absolutely talk about
this idea
seriously if you're willing to make an
assumption. And that assumption you
should realize could be wrong. The
assumption is, does space go on
infinitely far? Or could it be that you
go out sufficiently distant and you
maybe circle back to your starting point
as would happen on the surface of the
earth? We don't know the answer. But
under the assumption that space goes on
infinitely far, you can argue
convincingly with mathematics that there
would be copies of us out there.
Infinity universes can be connected with
our universe.
connections between the different
universes depends on the flavor of the
multiverse that you look at. If you're
thinking about an infinitely large
universe, then yeah, in principle you
could start here and in principle you
could pass through those universes if
you had enough longevity and if you
could travel fast enough. But there are
other versions of infinite universes
such as that from quantum mechanics
where you really couldn't jump from one
universe to another. That's not the way
that version of the multiverse emerges.
So it's completely dependent on the
flavor of multiverse that you're
interested in. Is UFO visiting us? Look,
in principle, is the idea that we could
be visited by aliens a crazy idea? No,
it's not crazy. It's conceivable. I
allow it as a logical possibility, but
it's so far-fetched that it's not an
idea that I at all take seriously. And
if you're interested, I could tell you
why, right? Which is simply
this. Planet Earth, you know, it took a
few billion years for life to really
take hold and ultimately for intelligent
life to emerge. So the time scale from
the birth of a planet to the emergence
of life is on the order of billions of
years. Which means out there in the
cosmos, if there are other planets with
living systems, likely they will be
either a billion years behind us or a
billion years ahead of us, it would take
an unlikely coincidence for them to be
at roughly the same evolutionary stage
that we are right now. If they're a
billion years behind us, they're not
building spaceships and visiting planet
Earth. If they're a billion years ahead
of us, they're not building spaceships
and coming to planet Earth because they
don't care about us because we are these
puny little ants. We are the pen. Yes,
we're nothing compared to them. They
have no interest in us whatsoever. And
moreover, let's say that they're doing
some strange anthropological
archaeological mission to see what's
happening on planet Earth just as a a a
science experiment for some advanced
student in a school that's a billion
years ahead of us. You really think
they're going to have to uh evade our
detection mechanisms? They won't be
smart enough to be able to shield
themselves if they want to be shielded.
we're going to catch sight of them with
our rudimentary detection equipment.
That's so ludicrous. So this idea that
they would be floating around and then
trying to evade our detection is so
anthropomorphic. It's so 21st century,
even 20th century anthropomorphic that
it's kind of ridiculous. I think many
people have a desire for there to be
more to reality than the surface
experience. And I think this comes from
a certain sense of longing, a longing to
have a greater impact on the universe,
to have a greater connection to the
universe, to have lives that matter more
than they might seem to on the surface.
And this drives people to take seriously
certain weird phenomenon because it fits
that urge. It fits that sense that we're
chosen or we are privy to this deep
truth that others have missed. It makes
us important if that's true. My own
feeling is if only these people
understood science a little bit better.
Quantum mechanics itself can provide
that. Quantum mechanics enough magical.
It's so magical. It's so bizarre. It's
so strange that even Albert Einstein
never fully accepted the things about
the world that we now are pretty certain
are true after 50 more years of
experimental study. And so it feels to
me a lost opportunity to reach people
with the real ideas about the external
world because they're stranger than the
ideas about channeling. They're stranger
than the ideas about aliens visiting us.
And to me, they're more intriguing and
more gratifying because there's
experimental evidence behind it. And
that's I think the real lost
opportunity. Should we seriously talk
with the people? Do I talk? I seriously
I do my best to talk seriously with
people about these ideas through books,
through television shows, through this
kind of a conversation. That's why I'm
here right now. And so the hope is that
people can be drawn in by the weird
wonderful reality that science has
revealed as opposed to the madeup
imaginative minations of an overworked
mind that's searching for something to
latch on to to give their life meaning.
String theory I agree that string theory
is a beautiful mathematical structure. I
agree that there is zero experimental or
observational data establishing that
string theory is the correct theory of
the universe. So what do you do? And it
doesn't work when we have more than 11
dimensions. And the theory
absolutely requires that the fabric of
space be far more subtle and rich than
Einstein himself or Newton would have
thought. The possibility of extra
dimensions is a natural consequence of
string theory. All of this is true.
Nevertheless, string theory does have
the capacity to describe the world as we
know it. Is it the right theory? We
don't know. And so, as the most
promising approach that we have yet
found for putting Einstein's ideas of
gravity together with the laws of
quantum physics, a union that has to
happen. You can't have physics without
general relativity and quantum mechanics
playing well together as string theory
is still the most promising approach. Of
course, we should pursue it
mathematically vigorously seeking to
extract some observation or experiment
that maybe one day we can carry out. But
as I said in the Washington Post
article, if somebody comes along
tomorrow and shows that there's a
mathematical flaw in string theory, we
should abandon it. This has never
happened. If tomorrow somebody should
come along and say, "Look at this new
idea that we can put general relativity
and quantum mechanics together and it's
immediately close to the world and we
can test it and let's go." Of course,
I'd be excited and I would jump at that
possibility as a new direction to
pursue. So, I'm not sitting here
dogmatically saying string theory,
string theory. No, not at all. I'm
saying truth, truth. Let's try to find
things that take us closer to truth. At
the moment, that is string theory in
terms of putting the laws of physics
into a unified framework. But is it
possible that we'll have something else
3 years, 5 years, 100 years that string
theory will be relegated to the dust bin
of science? Is that possible? Of course,
it's possible. Maybe Twister story will
replace string theory. Look, Roger
Penrose, so he did a remarkable job in
developing the twister idea and there's
beautiful mathematics within twister
theory. And in fact, there are subtle
ways that the twister idea has been in
dialogue with string theory. It's not as
though these ideas are at opposite ends
of some kind of theory spectrum. And so,
yes, is it possible that there's some
deep truth in Rogers approach? Yes. Is
it possible that there's some deep truth
in the string theoretic approach? Yes.
How will we figure it out? Continue to
work to develop the equations, develop
the mathematics, extract whatever
insight we can into the theories. That's
the only way to answer those deep
questions. Do you believe that we'll
ever find answer what connect quantum
world and classical reality? Yeah, I
mean we're still struggling even and
this is an important lesson. We're still
now struggling a h 100red years after
quantum mechanics was written down by
Heisenberg and Schroinger. This is 1925
and 1926. A 100red years later we can
use the equations to make predictions
that are borne out by experiment. We can
use the equations to engineer things
like integrated circuits making
everything from, you know, cell phones
to laptop computers that have
revolutionized life on this planet. And
yet, even with those successes, there
are deep questions within quantum
mechanics that we've yet to resolve. And
the biggest one is how do you go from
the quantum description of a reality
that is described as a fuzzy haze of
probabilities which is the language of
quantum physics. How do you go from that
to the definite reality that we all
experience every moment of our lives?
What's the transition from the quantum
to the matter is transformed from the
quantum world to classical reality? Yes,
that's the deep question. Now there are
many physicists who think that's a
nonquest. Neils Boore, founder of
quantum mechanics, thought that was a
non question. He said you're thinking
about things wrong. You're stuck in an
old mindset. The new mindset, Bore said,
is you have a realm of classical
equipment and that's the stuff that we
see in laboratories and you always use
the classical language to describe those
things. And then when you're talking
about the molecules and atoms and
particles, you use the quantum language
only down there. The problem with that
perspective is that the equipment is
made of the very same ingredients that
you use quantum mechanics to describe.
It's made of the electrons and the part
protons and the neutrons. And so if
quantum mechanics describes the
ingredients in the equipment, then it
must describe the equipment, which is
nothing but a conglomeration of the
ingredients. And it's that step that
bore would somehow resist and it's that
step that we are still struggling to
understand. Quantum mechanics is for you
local or non-local. Quantum mechanics as
far as we can tell is non-local. And
this is one of the deep insights that
came from the work of John Bell working
in the 1960s. A name that most people
have never heard of. Everybody knows
Einstein. They should because it was
John Bell almost as a hobby. He was
working at CERN particle accelerator was
working on other things but in his spare
time like to think about the foundations
of quantum mechanics and in his work he
was able to reveal a test to determine
whether or not certain ideas that
Einstein had that the universe was local
what you do here only affects things
here and that it was real that particles
always have definite features he came up
with a test of Einstein's view nobody
thought you could test Einstein's view.
It was just metaphysics ideas. Go away
Einstein. You're just thinking
philosophy. We're physicists. Which is
basically what people said toward the
latter decades of Einstein's life. But
John Bell said, "No, no, no. This is not
just philosophy. This is physics. We can
actually test whether these things
Einstein was saying are true." And when
the tests were done, they to most
people's satisfaction revealed that
Einstein's view that the universe was
local. That that was not true. That the
universe is non-local. In a sense, what
you do here can in a very specific
quantum way be connected to something
that happens over there. Don't you think
that we were not programmed to
understand the universe, but just only
to survive? Absolutely.
Our brains, like the rest of our bodies,
like every species on planet
Earth, is here because it survived. And
it survived because survival of the
fittest. We evolve over time to have the
capacities that allow us to get the next
meal or to find shelter or to avoid a
predator. That's why we are here. And
our brains do that by finding patterns
in the external world. Because if you
can see a pattern out there, you've got
a leg up in the battle for survival. If
you can maybe predict with some
certainty what's going to happen next
while your competitor can't, you're more
likely to win, to survive. That's why
we're here. So, as a physicist, you are
fighting with nature. I wouldn't say
that we're fighting with nature. What I
would say is once our brains gained the
capacity to recognize patterns that
aided survival, that capacity then went
overboard. It evolved to a place where
it could spot patterns that are
irrelevant to survival. And then as we
began to conquer the natural world where
we didn't have to spend all our time
gathering fruit and nuts or throwing a
spear at an antelope when we had enough
time, we could use that pattern
recognition capacity to start to think
about things like the pattern of the
motion of the planets, the pattern of
the motion of objects that we throw, or
even then the pattern of the motion of
the electron in the atom or the pattern
of the energy that comes out of the
accretion disc around a black hole.
These are just extensions of our
capacity to recognize patterns that were
at first in the service of survival. But
now we have not fought against nature.
We've leveraged that capacity to go even
further. Can molecules be involved in
the natural selection process? I think
molecular Darwinism, as we often call
it, is a vital part of how the world has
evolved. Many of us, when we learn about
evolution by natural selection in
school, at least here in the United
States, it's always at the level of
living systems. Living systems, they
have progeny. The progyny won't have
exactly the same characteristics as
their parents. And those new
characteristics which aid in survival,
they will spread widely because the
bearer of those characteristics will
have a better chance of living to the
age of reproduction. Now that's only at
the level of living systems. There's a
version of that that happens at the
level of molecules. Molecules can have
children, so to speak. They can have
progeny. Molecules can learn the trick
of replication. And once a molecule can
make a copy of itself, we recognize that
no copying process is ever perfect.
There will always be mutations, slightly
different molecules. And those mutations
that aid in the process of making more
replicants, they will spread widely. So
the molecular demographics will become
dominated by those molecules that can
reproduce swifter, faster, with greater
economy and greater stability. So in
that sense molecules themselves fight
other molecules chemical combat that
ultimately yields refined molecules and
those are the molecules that ultimately
make up living systems. What's about the
entropy in the universe? Can the actions
the molecules increase effects increase
entropy in the universe? Yeah, every
physical process by and large except for
you know very unlikely events results in
an increase in entropy for the basic
reason that entropy is simply a measure
of the number of ways that a given
system can be realized. And if there are
more ways that a system can be realized,
it's more likely that that configuration
will come to be. And so over time,
entropy increases at every level. At the
level of molecules, at the level of
living systems, at the level of the
universe. Now, it may not always seem
that way because we can do things that
seem to decrease the amount of entropy,
decrease the amount of disorder. We can
order a system using our brains and
using our valitional capacities. But if
you take into account the amount of
entropy that our bodies create in the
process of yielding that ordered system,
then the overall entropy always
increases over
time. Uh entropy and evolution of the
universe are what mainly determine
operations in the universe. All
operations in the universe. Yeah. When I
think about the dominant forces at work
guiding the cosmic evolution, I do think
of it in terms of entropy and evolution.
Entropy is this drive toward ever
greater disorder. Evolution is this
drive toward ever greater refined
systems that are able to replicate with
greater capacity. And so they kind of
seem like at opposite ends of the
spectrum. entropy driving us toward
disorder, evolution in a sense driving
us toward order. Now, in a sense,
therefore, these two forces, they kind
of battle against each other during the
unfolding of the cosmos. Ultimately,
entropy wins. If you look at the far
future of the universe as we can
understand it using our mathematical
equations that describe the laws of
physics, it's pretty clear that every
ordered system in the universe
ultimately
decays falls apart. Yes. Every single
system. Every single system. So stars
ultimately run out of nuclear fuel and
either explode or turn to a a simmering
smoldering mass. They lose that
beautiful ordered structure that gives
rise to heat and light that comes out of
a star during its living system. Even
black holes ultimately Stephven Hawking
taught us mystery of black holes a big
mystery of black holes but there's some
aspects that we understand well and
Stephen Hawking taught us that black
holes emit radiation slowly but they
emit radiation over time. So their
configuration ultimately gives rise to a
bath of particles, disordered particles
that waft through the universe. So every
system that may embody order at a given
cosmological epoch ultimately
disintegrates, falls apart, gives rise
to a disorderly end product. All we know
about the human consciousness is that I
have consciousness. You have
consciousness. This director chair does
not. That's only one thing we know about
the
consciousness. Well, there would be
people who would debate even the
statement that the chair doesn't have
consciousness. I agree. I don't think
that it does. But when we try to
understand the basis of consciousness,
we run up against what's known as the
hard problem. And the hard problem is
simply that your brain and my brain and
everybody's brain is made up of
molecules and atoms and particular
configurations.
If the individual
particles don't have inner worlds of
subjective experience, conscious
self-awareness, if the particles don't
have that, how is it that by putting a
lot of particles together, you do yield
an inner world of sights and smells and
emotions, this inner world that we all
have playing out inside of our heads,
where does it come from? Some have
suggested that the starting point of
that puzzle is incorrect. Maybe the
particles do have some kind of version
of consciousness, some kind of
protoconciousness, a little bit of
consciousness in the electron, in the
quark, in the protons and maybe that
little bits inside of things. And
therefore this chair from this
perspective would embody a certain
rudimentary kind of consciousness
because the ingredients themselves would
embody that. This is not an approach
that has convinced me. But I understand
why people introduce this idea because I
cannot answer the question of how can a
collection of mindless particles gain
mindfulness? How does that happen?
Nobody can answer that question. My
intuition tells me that consciousness
somehow emerges an emergent phenomenon
when you have particles, molecules,
atoms in a sufficiently coherent
arrangement. But if you ask me how does
that happen, I remain at a loss because
I don't know and nobody knows the
mechanism by which consciousness emerges
from orderly structures. My guess is
that one day we will understand how that
happens. But there are some who say
that's too optimistic a viewpoint. You
can't get consciousness from something
that's not conscious. You can't take a
bunch of particles each of which has no
consciousness whatsoever. Put them
together and have consciousness emerge.
Some people feel that very very
strongly. Maybe consciousness is born in
the quantum. Yeah, I have I have no
doubt that quantum physics in some way,
shape or form is important to
consciousness because quantum physics is
important to the way physical things in
our universe behave. And those physical
things include of course the particles
that make up the atom and the atoms that
make up the molecules and the molecules
that make up the cells and the cells
that make up the brain which somehow has
conscious awareness. So quantum
mechanics has to be at some level part
of the story. But I do not think or at
least I do not see any evidence that the
structure of quantum mechanics per se
necessarily yields consciousness. To me
it's more it's the laws of physics
together with the orderly structures
that are the substrate within which
consciousness takes place. And so I
don't see a direct route from quantum
mechanics to consciousness at least not
in the way that I think Roger has
imagined it. I need to ask you about
free will. If do you feel if do you
understand the difference between free
will and consciousness? Professor
Sapolski deeply believe that there is no
free will. We are biological machines.
Everything is determined by the cells by
molecules uh by
atoms. Do you feel the difference
between consciousness and will? Yes. So
the question of free will hinges on your
perspective regarding
consciousness. If you believe, as I do,
but I do not have proof, but if you
believe that consciousness is ultimately
reducible to physical processes,
biological processes, chemical
processes, if that's all that
consciousness is, then you
pretty inviably come to the conclusion
that there is no free will. Why is there
no free will? It's so sad. It is sad in
a way but in a way it's actually I think
quite liberating. But again the argument
is if the ingredients from which
consciousness emerges the particles the
molecules the atoms if they are governed
by physical law you and I and nobody
else has the ability to intercede in the
lawful progression the lawful behavior
of those particles. So when you in your
mind make a decision or have a thought
ultimately if that conscious awareness
is nothing but molecules moving one way
or another you can't control those
motions and therefore you can't control
what's happening inside your head. You
mean that we are not determined to
answer the question what consciousness
is? Well it depends what you mean by
determined. So there's two kinds of
determination within physics and they've
been used in different periods of time.
In the old classical physics prior to
quantum physics, the idea of having a
determined system is you tell me the
state of the system right now, the
positions and the velocities of all the
particles and I'll simply use the laws
of physics to predict what that system
will be like 5 minutes later or an hour
later or a year later. The initial
conditions and the laws of physics
determine how things will be. Period.
End of story. That's classical physics.
Quantum physics which has supplanted
classical physics says something a
little bit differently. It says tell me
how things are now as best as possible.
Describe the state of the system and I
will use the laws of quantum physics to
predict the likelihood that things will
be one way or another way or another way
still in the future. You can only
predict probabilities. But those
probabilities are just as determined in
quantum physics as the outputs were
determined in classical physics. It's
just you're determining something else.
So to my mind, you can sort of have your
cake and eat it. People worry, if I
don't have free will, does that mean you
can predict what I'm going to say in two
seconds? Answer is actually no. The best
you could do is predict the probability
that I'd say one thing or another or
another still. And so there's an open
quality to the future in quantum physics
that you would not have in classical
physics. So yes, I do not believe that I
have free will, but I also understand
that you can't use the laws of physics
to predict with 100% certainty what I
will do because you can only predict
probabilities of one or another outcome.
Human thoughts itself, it's a lifetime
limitation in the universe. What does it
mean? Well, if you believe as I do that
thoughts are physical processes, that
there's
no structure beyond the physical that
somehow is the place where thoughts
originate and take place. I'm not going
to go to any of those ideas. I don't
even know what they mean. So if I think
of thought as a physical process, every
physical process results in an increase
in entropy. Energy a little bit
different. Every thought and every
physical process requires energy but the
output of the process through which that
energy is used is to increase entropy.
The amount of energy can stay fixed but
the energy degrades over time. And that
degraded energy is what we mean by
disorder or entropy. The reason why this
is important is the following. Right
now, as we're talking, I am producing a
lot of entropy. Hopefully, not in the
ideas that I'm communicating, but rather
because I am giving off heat. I am
emitting waste to the environment. And
if you had the right instrument, you'd
see the infrared light coming off of my
head. that is turning energy into less
useful energy that infrared radiation is
hard to make use of. That is what we
mean by entropy in this room. This room
is very good at being able to absorb the
heat, the waste, the entropy I'm
producing. But in the far future as the
temperature of the universe comes down,
you can argue convincingly with
mathematics that there will come a point
when the universe can't absorb the
entropy. It can't absorb the heat that
thought itself creates. At that point,
if a thinking being thinks one more
thought, they will burn up in the
entropic waste produced by the process
of thought itself. They will die. There
will be no further capacity for thought
to take place. Human beings determine
entropy. Human beings create entropy as
does every other living system as does
every other physical process in the
universe. How do you define the truth?
What truth is for you? Well, I think
truth comes in a number of varieties.
There is something that I like to think
of as objective truth which speaks to
the qualities of the external world that
we attempt to describe using
mathematics. Be it the general theory of
relativity, be it quantum mechanics.
These are
mathematical approaches to try to get at
the truth of the physical processes that
take place in the universe that have
been holding sway since the big bang
giving rise to stars and galaxies and
planets and on this planet living
systems. There's also another variety of
truth which is a more internal
subjective truth. These are the truths
that every human being holds. Truth.
Yes. These are the truths that every
human being holds within their mind.
There are things that deeply matter to
me. My family, my parents, the things
that I spend my time on, my perspective
on the political situation. These are
vital truths to me as a human being, but
they're not objective. Not everybody
will agree that these are fundamental
truths of the universe. They're things
that matter to me as an individual
human. Often we get these mixed up.
Things that people think of as objective
truths often times are just subjective
truths that matter to them. And having a
clear understanding of the truths that
are external and out there versus the
ones that are internal is a vital
distinction to make. You think that we
can
discover mathematical idea? Yeah, I
would use a slightly different word. I
would say we invent mathematical ideas.
We don't discover them. To discover them
would suggest that they're out there
waiting to be found. You just need to
unearth them. Somebody else created them
or the universe created them and they're
out there. And I don't think there could
be any possibility that this is true.
Mathematics is a language that we humans
developed in order to find a very
quantitative and accurate approach to
embodying the patterns that we see in
the external world. We invent
mathematics the theorems and the proofs
that mathematicians
proudly publish in papers and journals
around the world. It's not that they
don't have value, but they are truths
that emerge within the language of
mathematics that we invent. There is no
meaning to these statements, to these
theorems, to these proofs without the
language of mathematics itself. And we
invent that language. And so take the
Pythagorean theorem. A2 + B2= C^2. We
invent the idea of a triangle. There's
no real triangle in the external world.
We invent the idea of a line. We invent
the idea of a right angle. There's no
real right angle in the external.
They're close to right angles, but we
invent the ideas and then we find
interesting features about the concepts
that we invent. Now, most mathematicians
recoil at this idea because somehow the
validity and value of what they're doing
for many rests upon finding external
truths, things that are out there that
will always be true. And my answer to
that is the Pythagorean theorem. A
square plus B2 plus C². It only has
meaning when it's resonant inside of a
head that can understand it. And in the
far future, when there are no thinking
structures left, when there's nobody
able to think anything at all, the
Pythagorean theorem will not exist.
Where will it be if it's not resonating
inside of a mind that can understand it?
To say that math is out there
independent of us has as little validity
as saying that there is a deity out
there independent of us doing things.
And if you're willing to go in that
direction, then I believe you're
undercutting the logical structure of
the insights that we're able to gain
about who we are and what we do. Can
physics allow for God evidence? Of
course, physics can allow for God. It
could be that there is a god. I can't
prove that there isn't a god. Just like
I can't prove that mathematics isn't out
there. The best that anyone can do is
marshall the most convincing argument
based upon things that we know about
things that we've seen that we've
observed the data that we have. There is
no data. There is no evidence that I've
ever seen that gives me any confidence
that the idea of a god is real. That is
not proof that God is not real. It's
merely giving you insight into my
thinking and the thinking of many others
as well as to why this might not be
true. But could it be that there's a God
out there and carefully has arranged
things so that there won't be any
evidence? So that the God has hidden
their role in the world and just maybe
given clues that only the world's
priests and imams and and rabbis can
find. Maybe, but I don't find that a
plausible way of looking at the world.
Religious people like you. Do religious
people like me? I've found that I can
have conversations with anyone and we
can leave that conversation feeling good
because my approach to the world is not
to undercut someone's position but
rather to hear them and to see the
degree to which their perspective can be
integrated into my own. So unlike some
of my colleagues who say religion should
be wiped off the face of the earth that
it's the most egregious and awful result
of civilization. I don't feel that way
at all. I find religion to be a
beautiful structure that speaks to who
we are and what matters to us and the
ideals that we have. Of course, religion
can be used for bad just the way nuclear
understanding can be used for bad or
good. And so religion as a tool can have
some very negative
consequences. But viewed in the most
positive light, religion is a beautiful,
really spectacular invention of the
human mind. The thing that we're most
terrified about as human beings is our
mortality. How wonderful to invent a
structure
whereby our death is not the end of our
existence. Our death is merely a step
within a much larger story. And so
that's a very beautiful way of quelling
the existential anxiety that comes with
mortality awareness. That to me is an
internal truth for those who believe it.
It is not an objective external truth.
But internal truths matter. They're
valuable. There is a William James book
from 192. Do you know that? Yes, I do.
Why varieties of religious experience?
Yeah. Why we need religion? Why we need
to be under control superpower? Yeah,
absolutely. William James is a hero of
mine because here you have a a scientist
trying to understand the human condition
through the lens of rational thought and
rational gathering of data and rational
evaluation of people's experiences. And
William James came out of that
experience, you know, understanding the
worldwide experience of religion and
religious phenomenon from very different
perspectives and came with a very
beautiful perspective on how religion
meets certain needs that we have. how
religion serves certain purposes for we
as human beings crawling around the
surface of a nondescript rock orbiting
around a nondescript star in the
outskirts of an ordinary galaxy. Who
wouldn't suffer from anxiety? Who
wouldn't suffer for terror and fear to
be thrust into that reality? And if
religion can help quell those fears, if
religion can tell a larger story that
can make an individual feel that their
life matters in the grander scheme of
things, then yeah, that's a powerful
structure and it's a powerful role for
this idea that we have invented called
religion. If you could find just only
one answer for just only one question
about the reality, what it would be? I
would like to understand the nature of
time. Is time something that we impose
from our minds or is it somehow
intrinsic to the structure of reality?
That would be one big one. But if you
let me even dream even bigger, the
biggest question of all is why is there
something rather than nothing? Not empty
space, nothing, but why is there
anything at all? Logically, you could
imagine the absence of space and time
and matter and energy and everything.
What brought existence into being? But
outside the universe, there is nothing.
We don't know if there's even a notion
of outside the universe. The deepest
unresolved question at the heart of
quantum
mechanics. How does the probability
quantum haze transition in the defined
reality of everyday experience? Yeah.
Could you answer for that question? I
don't know an answer to that question.
That is the question that we were
discussing before. What is the means by
which a description of the world in
terms of probabilities turns into an
experience of the world that is
absolutely definite? How does that
transition take place? We've made a lot
of headway with ideas of so-called
decoherence and things of that sort, but
in terms of truly answering the
so-called quantum measurement
problem, nobody knows the answer. What
are you doing now? Tell me something
about your actual research. Yeah. So,
right now with a number of colleagues,
we've been studying the possibility that
the extra dimensions might have yet
weirder properties than your mind is
dimensional. uh you are still thinking
about dimensions. Yeah, we're certainly
still thinking about extra dimensions.
The possibility that the extra
dimensions might allow you to circumn
them. Maybe the extra dimensions is a
large circle, a shape that you can fully
transverse. And the reason this turns
out to be interesting, we found that in
these possible scenarios, you could send
a signal from here to someplace far away
and it could get there faster than the
speed of light. Faster than the speed of
light. It's impossible. That's what most
people would say and that's what we
thought too. But it turns out if you
send the signal Einstein said that it's
impossible the speed faster than light
doesn't exist. So we're completely
compatible with Einstein because locally
the speed of the signal is always equal
to light speed. But if you have an extra
dimension, there's two trajectories to
go from here to here. There's the direct
one from here to here, but there's the
indirect one where you spiral around the
extra dimension and get there. You would
think that spiraling around would take
you longer, but it doesn't. Even going
at light speed, you can beat the signal
that goes from here to there directly.
Effectively sending a signal from here
to there at faster than the speed of
light. Everything I do is theoretical.
Everything I do is mathematical. And so
yes, this is under the assumption, the
assumption that there's an extra
dimension in the shape of say a circle.
It's also making the assumption that we
live on a so-called membrane in string
theory that's moving along this extra
dimension. There's a whole set of
assumptions, but
remarkably with those assumptions you
can send a signal from here to there at
faster than the speed of light. Finizing
our meeting, um I need to ask you about
AI. Do you believe that we can ever
achieve something called AGI, strong AI,
superhumans AI? Without a doubt, I
believe that there's no obstacle
fundamentally to the capacities of these
artificially intelligent systems. Look,
I don't think there's anything special
about the biological brain that gives
rise to consciousness and intelligence.
I think that if you were to engineer a
version of what's inside of our heads in
silicon that in principle it could think
and feel and be intelligent and there'd
be nothing in principle stopping you
from cramming information and capacity
and and and chips and circuits that
allow that artificial structure to
operate at a level that's beyond our
capacity. So do I think that we will get
there? I do. And I don't think it's far
away either. AI it's for you more
something more than just only
statistical. Well, look, the approach
that the large language models have been
following is certainly one way. It is a
statistical approach based on large data
sets. But that's not the only way that
researchers have been and will continue
to try to achieve artificial general
intelligence. You could couple those
statistics with some model of the
external world, with some understanding
of the fundamental laws of physics, some
understanding of what we have already
learned in a very concrete framework.
That additional structure by itself in
principle could allow the probabilities
to get you to results that are more
relevant, more insightful. And so that
would be a more intelligent system
compared to one that's based purely on
the statistics. And that's merely one
approach. You've got some of the most
creative thinkers in the world that are
researching ways to make these systems
ever better. And I don't see any limit
to what it is that they can achieve. A
lot of people think that even our
language it's not enough to describe
what we created because AI, the world
AI, it's not artificial, it's real.
Yeah. We have also not one artificial
intelligent. We have archipelago of
islands that of course we integrate each
other but still there is not one
continent. Yes, I fully agree. The whole
notion
that intelligence can be organic or
artificial is itself an artificial
distinction. Right? You have systems
that can take in information and produce
useful information as output. And
whether that system happened to emerge
through the ordinary biological process
of a living system maturing or through
some system that we build. Well, it
doesn't really matter in the end of the
day. It determines on input versus
output. And if you can build some system
that is intelligent, it is a new kind of
intelligence, not necessarily an
artificial version of intelligence. I
have two final questions to you. The
first one is about your own congress,
World Science Congress. Why you founded
that? World Science Festival. Yeah. Why
Science Festival? Well, way back when we
began the World Science Festival, we
recognized an opportunity to get people
excited about forefront ideas in
physics, in mathematics, in computer
science, in cosmology, and chemistry and
biology. And so we said, why don't we
create a gathering place where we'll
bring the world's leading scientists to
be in direct conversation with the
general public? And so this idea caught
on. And you know, at our first
gathering, we had 120,000 people come to
the events. And so we recognized that we
had really tapped into something that
mattered to people. And so we've been
pursuing it ever since. Who today
inspired you the most? Who
uh who was your master? your father a
musician or Yeah, my father had a had a
profound impact on me and today well my
dad was a musician and a composer who
did not have even a high school
education but was deeply interested in
the world and he was seeing it from the
perspective of art perspective of music
and that inspired me that there are so
many different ways to understand
reality and each of them gives you new
insights and so that's why I don't spend
my time just doing physics per se and I
think my father's influence is a big
part of that. I want to understand the
various ways of seeing into the workings
of the world be it from art, science,
literature, music, all of these provide
a more rich engagement with reality.
Thank you for your time. My pleasure.
Thank you.