Kind: captions
Language: en
the following is a conversation with
frank wilceck a theoretical physicist at
mit
who won the nobel prize for the
co-discovery of
asymptotic freedom in the theory of
strong interaction
quick mention of our sponsors the
information
netsuite expressvpn blinkist
and a sleep check them out in the
description to support this podcast
as a side note let me say a word about
asymptotic freedom
protons and neutrons make up the nucleus
of an atom strong interaction
is responsible for the strong nuclear
force that binds them
but strong interaction also holds
together the quarks
that make up the protons and neutrons
frank wilcek
david gross and david pulitzer came up
with a theory postulating
that when quarks come really close to
one another the attraction abates
and they behave like free particles this
is called
asymptotic freedom this happens at
very very high energies which is also
where all the fun is this is the lex
friedman podcast
and here is my conversation with frank
wilcheck
what is the most beautiful idea in
physics
the most beautiful idea in physics is
that we can get a compact description of
the world that's
very precise and very full
at the level of the operating system of
the world
um that's an extraordinary gift
and we get we get worried when we
uh have find discrepancies between our
uh description of the world and and
what's actually observed
at the level even of a part in a billion
you actually have this quote
from einstein that the the most
incomprehensible thing
about the universe is it's co is that it
is comprehensible something like that
yes that's so that's the most beautiful
surprise that i think uh
that that really was the to me the
most profound result of the scientific
revolution of this
of the 17th century with uh
the shining example of newtonian physics
that you could
aspire to completeness precision
and a concise description of the world
of the operating system
and it's gotten better and better over
the years
and that's the continuing miracle now
there are a lot of beautiful
sub-miracles too
the form of the equations is governed by
high degrees of symmetry and
and they have a very surprising kind of
mind-expanding structure especially in
quantum mechanics
but if we have to say that the single
most
beautiful revelation is that
in fact uh the world is comprehensible
would you say that's a fact or hope it's
a fact
we can do we you can point to things
like
uh the rise of
uh gross
pro gross national products grow you
know per capita
around the world as a result of the
scientific revolution you can see it all
around you
uh uh uh in in recent developments with
exponents
so exponential production of wealth
control of nature
at uh a very profound level
where we do things like sense tiny tiny
tiny tiny vibrations
to tell that there are black holes
colliding far away
or we uh test laws as i
alluded to whether to part in a billion
and do
you know things and what appear on the
surface to be entirely different
conceptual universes i mean on the one
hand
pencil and paper or nowadays computers
that that
calculate abstractions and on the other
hand magnets and accelerators and
detectors that look at the
behavior of fundamental particles and
and these
different universes have to agree or
else we get very upset
and that's uh it's an amazing thing if
you think about it so
and it's telling us that we do
understand a lot about nature at a very
profound
level and uh
there are still things we don't
understand of course but
as we get better and better answers and
better and better
ability to address difficult questions
we can ask
more and more ambitious questions well i
guess the hope
part of that is because we are
surrounded by mystery
so we've one way to say it if you look
at the growth the
gdp over time that we figured out quite
a lot and we're
able to improve the quality of life
because of that
and we've figured out some fundamental
things about this universe but we still
don't know how much mystery there is
and it's also possible that there's some
things that are in fact
incomprehensible to both our minds
and the tools of science like we the
the sad thing is we may not know it
because
in fact they are incomprehensible and
that's the open question is
how much of the universe is
comprehensible if we figured out
the the everything uh what's inside the
black hole
and everything that happened at the
moment of the big bang
does that still give us the key to
understanding the human mind
and the the emergence of all the
beautiful complexity we see around us
that's not uh like when i when i see
these objects
like i don't know if you've seen them
like cellular automata
uh all these kinds of objects where the
from simple rules emerges complexity yes
it makes you wonder maybe it's not
reducible to simple beautiful
equations the whole thing only parts of
it
that's the tension i was getting at with
the hope well
when we say the universe is
comprehensible we have to
kind of draw careful distinctions about
or uh
definitions about what what we mean by
by that
uh both the university and the con and
the comprehensive
exactly right so uh the
so in certain areas
of understanding reality
we've made extraordinary progress i
would say
in understanding fundamental physical
processes
and getting very precise equations that
really work and
allow us to do uh the profound sculpting
of matter
you know to make computers and iphones
and everything else and they really work
and they're extraordinary productions
uh on the other but uh
and that's all based on the laws of
quantum mechanics and you know they
really
and they really work and then uh
and they give us tremendous control of
nature
on the other hand uh as i said as with
as we get better answers we can also ask
more ambitious questions and there are
certainly things that
have been observed even in the
in what would be usually called the
realm of physics that aren't understood
for instance there seems to be another
source of mass in the universe the
so-called dark matter
that we don't know what it is and it's a
very interesting question what it is
then uh but also as you were alluding to
there
there's it's one thing to know the basic
equations
it's another thing to be able to solve
them
in in important cases so we run a
we run up against the limits of that in
things like
chemistry where we'd like to be able to
design molecules and predict their
behavior
from the equations we think the
equations could do that
in principle but but uh
in practice it's very challenging to
solve them in
in all but very simple cases uh
and then there's the other thing which
is that a lot of what we're interested
in
is uh historically conditioned it's not
uh it's not a matter of the fundamental
equations but about
what has evolved or come out
of of the early universe and formed into
people and frogs and societies and
things
and the laws of physic the basic laws of
physics only take you so far
in the in that it kind of provides a
foundation but doesn't
really you need entirely different
concepts to deal with
uh those kind of uh and
all we one thing i can say about that is
that the laws themselves
point out their limitations that they
kind of their laws for dynamical
evolution so they tell you what happens
if you have a certain starting point but
they don't tell you what the starting
point
should be at least yeah and
uh the other the other thing that
emerges from the equations themselves
is the phenomena of chaos
and sensitivity to initial conditions
which tells us that you have that
there are intrinsic limitations on how
well we can spell out the
consequences of the laws if we try to
apply them see all the apple pie
if you want to what does it make an
apple pie from scratch
you have to build the universe or
something like that well
you're much better off starting with
apples than starting with quarks
let's put it that way in your uh book a
beautiful question you ask
does the world embody beautiful ideas so
the book is centered around this
very interesting question it's like
shakespeare you can like dig in and read
into all the different interpretations
of this question
but at the high level what to use the
connection between
beauty of the world and physics of the
world
in a sense we now have a lot of insight
into what the
the laws are the for the form they take
that and
allow us to understand matter in great
depth and control it
as we as we've discussed uh
it's an extraordinary thing how
mathematically ideal
those equations turn out to be in the
early days of greek philosophy
uh plato had this model of
atoms built out of the five perfectly
symmetrical platonic solids so there was
somehow the idea that mathematical
symmetry
uh should govern the world and uh we've
outplated plato by far
in modern physics because we have
symmetries that are much more extensive
much more powerful
that turn out to be uh the ingredients
out of which we construct our theory of
the world
and and it works and uh
so that's certainly beautiful so
the the math the idea of symmetry which
is
uh a driving inspiration
in much of human art uh especially a
decorative art or like the alhambra or
in
wallpaper designs or things you see
around you everywhere
uh also turns out to be the dominant
theme in
modern fundamental physics symmetry and
its manifestations
the laws turn out to be very to have
these tremendous amounts of symmetry you
can change
the symbols and move them around in
different ways and they still have
the same consequences uh
that so that's that's
uh beautiful and uh
that that uh these things uh these
different
these concepts that humans find
appealing
also turn out to be the concepts that
govern how the world actually works
and i don't think that's an accident i
think the humans
were evolved to be able to interact with
the world in
in ways that are advantageous and to
learn from it
and so we are naturally evolved or
designed to enjoy beauty and
and it's a symmetry and this and the
world has it and that's no
that's why we that's why we resonate
with it well it's interesting that the
ideas of symmetry emerge at
all at many levels of
the hierarchy of the universe so
you're talking about particles but it
also is
at the level of chemistry and biology
and
um and the fact that our
cognitive sort of our perception system
and whatever our cognition is also finds
it appealing or somehow our sense of
what is beautiful is grounded in this
idea of symmetry or the breaking of
symmetry
symmetry is at the core of our
conception of beauty whether it's the
breaking or the non-breaking of the
symmetry
it makes you wonder why
why like uh so i come from russia
in the in the question of dostoyevsky
he's
he has said that beauty will save the
world maybe
maybe as a physicist you can tell me
what do you think he meant by that
i don't i don't know if it saves the
world but it does turn out to be a
tremendous source of insight into the
world
when we uh investigate kind of the
the most fundamental interactions things
that are
hard to access because they occur at
very short distances between
very uh
special kinds of particles whose
properties are only revealed at high
energies
we don't have much to go on from
everyday life but so we have when we
guess what the
so we and then the experiments are
difficult to do so you can't
you can't really uh follow a very
uh holy empirical procedure to
sort of step in the baconian style
figure out the laws kind of step by step
just by accumulating a lot of data
what we actually do is guess and the
guesses
are kind of aesthetic really what what
would be a nice description
that's consistent with what we know and
then you try it out and see if it works
and then
and by gosh it does in in some
in many profound cases uh so
there's that but there's another source
of symmetry which i didn't
talk so much about in uh
in a beautiful question but does
uh relate to your comments and i think
very much relates to
uh the source of symmetry that we find
in biology
and uh in
in our in our heads you know in our
brain
which is that uh although i'd
well it is discussed a bit in in a
beautiful question and and
also in fundamentals is that
when you have
symmetry is also a very important means
of construction
so when you have for instance simple
viruses
that that need to construct their coat
their protein coat the coats often take
the form of platonic solids
and the reason is that the viruses are
really dumb
and they only know how to do one thing
so they make a pentagon then they make
another pentagon and they make another
pentagon and they
all glue together in the same way and
that makes a very symmetrical
object sort of so the rules of
development when you have simple rules
and they
go they work again and again you get
symmetrical patterns that's it's kind of
in in fact it's a recipe also for
generating
fractals you know really like uh
the kind of broccoli that has all this
internal structure and i
wish i had a picture to ship that many
people remember it from the
from the uh uh from the supermarket
and then and you say how did a vegetable
get so intelligent to make such a
beautiful object of all this
fractal structure and the the the secret
is stupidity you just do the same thing
over and over again
and uh in our brains also you know we've
we came out we start from single cells
and they reproduce and they they're each
one
does basically roughly the same thing
they
they uh the the program evolves in time
of course
different different modules get turned
on and off genetic
different regions of the genetic code
get turned on and off
but uh but basically a lot of the same
things are going on and they're simple
things and so you produce the same
patterns over and over again and that's
a recipe for producing symmetry because
you're getting the same thing
in many many places and if you look at
for instance the beautiful drawings of
rahman ikahal the great neuroanatomist
who drew the structure of different
organs
like the hippocampus you see it's very
regular
and very intricate and
it's symmetry in in this in
in that sense it's because it's it's
it's many repeated units that that
uh you can take from one place to the
other and see that they look more or
less the same
but what you're describing this kind of
beauty that we're talking about now
is a very small sample
in terms of space-time in a very big
world
in a very short brief
moment in this long history in your book
fundamentals
10 keys to reality i'd really recommend
people read it
you uh you say that space and time are
pretty big
or very big how big are we talking about
like what uh
can you draw can you tell a brief
history
of space and time it's easy to
tell a brief history but the details get
very
involved of course but uh one thing i'd
like to say is that
if if if you take a broad enough view
the history of the universe is simpler
than the history of sweden say
because you don't you your standards are
lower for for
but just to make it a a a
quantitative i'll just give a few
highlights and it's it's
it's a little bit easier to talk about
time
uh so let's start with that the big bang
occurred
we think the universe was much hotter
and denser and more uniform
about 13.8 billion years ago and that's
what we call the big
bang and it's been expanding and cooling
the matter in it has been expanding and
cooling
ever since so in a real sense the
universe is 13.8 billion years old
that's a big number kind of hard to
think about
a a nice way to think about it though is
to map
it on to one year so if
so let's say the universe just linearly
map the time intervals from
13.8 billion years on to one year so
the the big bang then is that on january
1st at
12 a.m and
uh you wait for quite a long time
before the dinosaur has emerged the
dinosaurs emerge on christmas
it turns out almost 12 months later
getting close to the end yes
and the extinction event that uh
let mammals and ultimately humans
inherit the earth from from the
dinosaurs occurred on december 30th
and all of human history is a small part
of the last day
and so so yes so we
we're occupying only a human lifetime is
a
very very infinitesimal part of this uh
interval of these gigantic cosmic
reaches of time uh and
in space we can tell a very similar
story in fact
a very uh it's convenient to think
that the size of the universe is
the distance that light can travel in
13.8 billion years that's
so it's 13.8 billion light years
that's that's how far you can see out
that's how far
things can signals can reach us from
and um that
is a big distance
because compared to that uh the the
universe
that the earth is a fraction of a light
second
so again we it's really really big
and so we have if we want to think about
the universe as a whole in space and
time
we really need a different kind of
imagination
it's not it's not something you can
grasp in terms of psychological time in
a useful way you have to think
you know you have to use exponential
notation and abstract concepts
to really get any uh hold on on
on these vast times and spaces
on the other hand let me hasten to add
that that doesn't make us small
or make the time that
we have to us small because uh
again looking at those pictures of
you know what our minds are in some
sense of components of our minds these
beautiful drawings of the cellular
patterns inside the brain
you see that there are many many many
processing units
and if you analyze how fast they operate
i try to estimate how many thoughts a
person can have in a lifetime that's
kind of a fuzzy question but i'm very
proud that i
i was able to define it pretty precisely
and it turns out we can we have time for
billions
of meaningful thoughts you know in a
lifetime
so so it's a lot we shouldn't we
shouldn't think of ourselves as terribly
small
either in space or in time because
although we're
small in those dimensions compared to
the universe where
we're large compared to
meaningful units of processing
information
and and being able to conceptualize and
understand things
yeah but 99 of those thoughts are
probably
food sex or internet related but yeah
yeah well they're not that's right only
like point one is nobel prize winning
ideas
but that's true but uh you know there's
more to life than winning nobel prizes
how did you um do that calculate can you
maybe break that apart a little bit just
kind of
for fun sort of an intuition of how we
calculate the number of thoughts the
number of thoughts right there they're
it's necessarily imprecise because a lot
of things are going on in different ways
and what is a thought
but there are several things that point
to more or less the same
[Music]
uh rate of being able to have meaningful
thoughts
uh for instance i'm the one that i think
is
maybe the most penetrating is uh
how fast we can we can process visual
images how to how do we do that
if you've ever watched old movies
you can see that that when well any
movie
in fact that in a motion picture is
really not a motion picture it's
a series of snapshots that are playing
one after the other
and it's the because our brains
also work that way we take snapshots of
the world
integrate over a certain time and then
go on to the next one and then
by post-processing create the illusion
of continuity and flow
we can deal with that and uh
the if the flicker rate is too slow
then you start to see that it's not it's
a series of snapshots
and you can ask what is the what is the
crossover when does it change from being
something that
that is matched to our processing speed
versus
too fast and and it turns out about 40
per second
and then if you take 40 per second as
as how well we how fast we can process
visual images you get
to several billions of thoughts uh
if you similarly if you ask what
what are some of the fastest things that
people can do well you can they can play
video games they can play the piano very
fast if
if they're skilled at it and again you
get to similar
uh units or how fast can people talk you
get to sim
you know within a couple of orders of
magnitude you get more or less to the
same
idea so uh so that's how
you can say that that there's there's
billions of
meaning there's room for billions of
meaningful thoughts
yeah i won't argue for exactly 2 billion
versus 1.8 billion it's not that kind of
question but
but i think any estimate that's
reasonable will come out
within say a hundred billion and a
hundred million
so it's a lot
[Laughter]
it would be interesting to map out for
an individual human being
the landscape of thoughts that they've
sort of traveled if you think of
thoughts as a set of trajectories uh
what what that landscape looks like i
mean
i've been recently really thinking about
uh
this richard dawkins idea of memes
and just all these ideas and the
evolution of ideas inside of one
particular human mind
and how there's there then changed and
evolved by
interaction with other human beings it's
interesting to think about
so if you think the numbers billions
you you think there's also social
interaction so these aren't
uh like there's interaction in the same
way you have
interaction with particles there's
interaction between human thoughts
uh that are perhaps that's that
interaction in itself is fundamental to
the process
of thinking like without social
interaction we would be
like stuck like walking in a circle we
need
we need the perturbation of other humans
to create
change in evolution once you bring in
concepts of uh
interactions and correlations and
relations
then you have what's called a
combinatorial explosion
that the number of possibilities rap
expands exponentially technically with
the number of
the number of things you're considering
and
uh it can easily rapidly outstrip these
these billions of thoughts that we're
talking about so
we we definitely uh cannot by brute
force
master complex situations and
or think about think of all the
possibilities in complex situations i
mean you know
even even something as relatively simple
as chess
is still something that human beings
can't comprehend completely even the
best players lose
still sometimes lose and they
consistently lose to computers these
days
uh and in computer science there's a
concept of
np complete so large classes of problems
when you scale them up beyond
a few individuals become intractable
and so that in that sense uh the world
is inexhaustible
but and that makes it beautiful that we
can make uh
any laws that generalize
efficiently and well can compress all of
that
combinatorial complexity just like a
simple rule that that itself is
beautiful
it's a happy situation and i i think
that that we can
find general principles of
sort of of the operating system that
are comprehensible simple extremely
powerful
and let us control things uh very well
and and ask profound questions
and on the other hand that the world is
going to be inexhaustible
that once we start asking about
relationships and how they evolve
and social interactions and the the
the we'll never have a theory of
everything in any meaningful sense
because
of everything everything truly
everything is
uh can i ask you about the big bang uh
so we talked about the space and time
are really big
but then and we humans give a lot of
meaning to the word space
and time in our in our like daily lives
but then can we talk about this moment
of beginning
and how we're supposed to think about it
that at the moment the big bang
everything was uh
what like infinitely small and then it
just
blew up we have to be careful here
because there's a
there's a common misconception that
the big that the big bang is like the
explosion of a bomb in empty space
that that uh fills up the surrounding
place
it is space it is yeah as we understand
it
it's the fact it's the the fact or the
hypothesis but
well supported up to a point that that
that everywhere in the whole universe
early in the history uh matter came
together into a very hot
very dense if you run it backwards in
time
matter comes together into a very hot
very dense and yet very homogeneous
plasma of all the different kinds of
elementary particles and quarks and
anti-quarks and gluons and photons and
electrons and anti-electrons everything
you know all of that stuff
like really hot really really
really hot we're talking about uh way
way hotter than the surface of the sun
uh you know well in fact if you
take the equations as we as they come
the the prediction is that the
temperature just goes to infinity but
then the equations
uh break down we don't you know we don't
don't really
with their various the equations become
infinity equals infinity so they don't
feel
that it's called a singularity we don't
really know uh this is running the
equations backwards so you can't really
get a sensible
idea of what happened before the big
bang we don't you know so
we need different equations to address
the very earliest
moments uh that uh
but so things were hotter and denser we
don't
really know why things started out that
way
we do we have a lot of evidence that
they did start out that way
uh but since most of the
uh you know we don't get to visit there
and do controlled experiments most most
of the
most of the record is is very very
processed and
we have to we have to use uh very
uh subtle techniques and powerful
instruments to
to get information that has survived
get closer and closer to the get closer
and closer to
the the beginning of things and
what's revealed there is that uh
as i said there what there undoubtedly
was a period when
everything in the universe that we have
been able to look at
and understand and that's consistent
with everything
is uh um
the was in a condition where it was much
much hotter
and much much denser but still obeying
the laws of physics as we know them
today
and and then you start with that so all
the matter is in equilibrium
uh and then with small quantum
fluctuations and run it forward
and then it produces in at least in
broad
strokes the universe we see around us
today
do you think we'll ever be able to with
the tools of physics
with the way sciences with the way the
human mind is we'll ever be able to get
to the moment of the big bang in our
understanding
or even the moment before the big bang
can we understand what happened before
the big bang i'm
i'm optimistic both that we'll
be able to uh measure more
so observe more and that we'll be able
to figure out more
so uh they're very very tangible
prospects
for uh observing the
extremely early universe so much even
much earlier than we can
observe now uh through looking at
gravitational waves
gravitational waves since they interact
so weakly
with ordinary matter uh
sort of send an un a minimally processed
signal from the big bang it's a very
weak
signal because it's traveled a long way
and diffused over long spaces
but uh but people are gearing up to try
to detect
gravitational waves that could have come
from the early universe yeah ligo's
incredible engineering project is the
most sensitive
precise yes devices on earth
the fact that humans can build something
like that is uh
truly awe-inspiring from an engineering
perspective right
and but these gravitational waves from
the early universe would probably be
of a much longer wavelength than lyco is
capable of
sensing so there's a beautiful
project uh that's contemplated
to put lasers in different parts
different locations in the solar system
you know we really really separated by
uh solar system scale differences like
artificial planets or moons
in different places and and see the tiny
motions of those relative to one another
as a signal of
of radiation from the big bang we can
also maybe
indirectly see the imprint of
gravitational waves from the early
universe
on uh the photons the the microwave
background radiation
that that is our present way of of
seeing
into the earliest universe but those
those photons
interact much more strongly with matter
they're much more strongly processed so
they don't
give us directly such an unprocessed
view of the early universe of the very
early universe
but if gravitational waves leave some
imprint
on that as they move through uh
we could detect that too and people are
trying our
as we speak working very hard towards uh
towards that goal it's so exciting to
think about a sensor the size of a solar
system
like uh that would be a fantastic i mean
that would be a pinnacle
artifact of human endeavor to me it
would be
such uh such an inspiring thing
that just we want to know
and we go to these extraordinary lengths
of making
gigantic things that are also very
sophisticated because what you're trying
to do
you you have to understand how they move
you have to understand
uh the properties of light that that are
being used interference between light
and
you have to be able to make the light
with lasers and understand the quantum
theory and
get the timing exactly right you know
it's an extraordinary
endeavor involving all kinds of
knowledge from the very strong
very small to the very large and all in
the service of
uh curiosity and built on a grand scale
so yeah
if we did that i love that you're
inspired both by by the power of theory
and the power of experiments so this is
the both both i think are
exceptionally impressive that the human
mind can come up with theories
that give us a peek into how the
universe works but also
construct tools that are way bigger than
uh
the the evolutionary origins we came
from right
and by the way you know the fact that we
can design those things and they work
yeah is an extraordinary demonstration
that we really do
understand a lot and then
in some ways and it's our ability to
answer
questions that also leads us to be able
to address more ambitious questions
so you mentioned that at the at the big
bang
in the early days things are pretty
homogeneous
yes but uh here we are sitting on earth
to uh hairless apes you could say
with microphones in talking about the
brief history of things you said it's
much harder to describe sweden than it
is
um the universe so there's a lot of
complexity
there's a lot of interesting details
here so how does this complexity come to
be do you think
it seems like there's these pockets yeah
we don't know how rare of like
uh we're hairless apes just emerge yeah
and then they came from the initial soup
that was homogeneous
was that uh yeah accident
well we understand there we understand
in broad
outlines how it could happen
we certainly don't understand why it
happened exactly and the way it did or
but but uh or you know
there are certainly open questions about
the origins of life and how inevitable
the emergence of intelligence was and
and how that happened
but uh in the very broadest terms
uh the universe early on
was quite homogeneous but not completely
homogeneous
there are there were part in 10 000
fluctuations in density within this
primordial plasma and
uh as time goes on
there's an instability which causes
those density contrasts
to increase there's a gravitational
instability where it's denser
the gravitational attractions are
stronger and so that brings in more
matter and it gets even denser
and so on and so on so so there's a
natural
tendency of matter to clump because of
gravitational interactions
and then the equations get complicated
when you have lots of things
clumping together uh then you know then
then we know what the laws are but we
have to to a certain extent wave our
hands about what what
what happens but uh the basic
understanding of chemistry says that if
things
and and the physics of radiation tells
us that if
as things start to clump together they
can radiate give off some
energy so they don't just they slow down
they as a result they lose energy they
conglomerate together
cool down form things like stars form
things like planets
and so in broad terms there's no mystery
there's
that that's what the scenario that's
what the equations tell
you should happen but because
it's a process involving many many
fundament individual units uh
the the the application of the laws that
govern
individual units to these things is is
very delicate uh you know
computationally very difficult
and more profoundly uh the equations
have this probability of chaos or
sensitivity to initial conditions which
tells you
tiny differences in the initial state
can lead to enormous differences
in the subsequent behavior so so
physics fundamental physics at some
point says
okay chemists biologists this is your
problem
and and uh and then
again in broad terms we know how
uh it's conceivable that that the
humans and things like that can can uh
that how complex structure can emerge
it's a matter of uh having
the right kind of temperature and the
right kind of stuff
so you need you need to be able to make
chemical bonds that are reasonably
stable and
be able to make complex structures and
we're very fortunate that carbon has
this
ability to make uh backbones and
elaborate branchings and things so you
can get complex things that we call
biochemistry
and and yet the bonds can be broken a
little bit with the help of
energetic injections from the sun so you
have to have
both the possibility of changing but
also the possible
useful degree of stability and we know
at that
very very broad level
physics can tell you that it's
conceivable yeah if you want to know
what actually
what what's what what really happened
what really can happen then you have to
work a bit to
go to chemistry if you have if you want
to know what actually happened
then you really have to consult the
fossil record in biologists and so
so uh but but it's it so these
these ways of addressing the issue
are complementary in a sense they but
they uh
they uh they use different kinds of
concepts they use different
uh languages and they address different
kinds of questions but
they're they're not inconsistent they're
just
complimentary it's kind of interesting
to think about
those early fluctuations as our
earliest ancestors yes that's right so
it's far it's amazing to think that uh
you know this is
the modern answer to the uh
or the modern version of uh
the what the hindu philosophers had that
art thou
if you ask what okay that those those
little quantum fluctuations in the early
universe
are the seeds out of which uh complexity
including uh plausibly humans really
evolve you don't need anything else that
brings up the question
of uh asking for a friend here if
there's
uh you know other pockets of complexity
commonly called as uh alien intelligent
civilizations out there well we don't
know for sure but i
i have a strong suspicion that the
answer is yes because
the uh the one
case we do have at hand to study
here on earth uh we sort of know what
the conditions were that were helpful to
life the right kind of temperature the
right kind of star
that that keeps maintains that
temperature for a long time the liquid
environment of water
and once those conditions
emerged on earth which was roughly four
and a half billion years ago it wasn't
very long before
what we call life started to leave
relics
so we can find the
forms of life primitive forms of life
that are almost
as old as the earth itself in the sense
that once the earth
became reason was was returned from a
a a very hot boiling thing and cooled
off into a solid mass with
it with water uh life emerged very very
quickly so
so it seems that these general
conditions for life
uh are enough to to make it happen
uh relatively quickly now
the other lesson i would i think that
one can uh draw from this one example
it's dangerous to
the drug lessons from one example but
that's all we've got
uh and uh that that the emergence of
intelligent life is a different
issue altogether it uh that took a long
time
and seems to have been pretty contingent
uh the you know the the for a long time
well for most most of the history of
life
it was single-celled things
you know uh yes even multicellular life
only rose about 600 million years ago
so much after you know so and the the
uh and then
intelligence is kind of a luxury you
know if you think
uh many more kinds of creatures
have uh big stomachs
than big brains and in fact uh most most
most have no brains at all in any
reasonable sense
that that then uh and the dinosaurs
ruled for a long long time and some of
them were pretty smart but
they they were at best bird brains
because you know birds
came from the dinosaurs uh and
uh and it could have stayed that way you
know and and
then human and the emergence of humans
was very contingent and kind of a
very very recent development on
evolutionary time scales
and uh you can argue about the level of
human intelligence but it's you know i
think it's
that that's what we're talking about and
it's very it's very impressive and can
ask these kinds of questions and discuss
them intelligently
uh the uh so
i guess my my so this is a long-winded
answer or justification of
my feeling is that uh the
conditions for life
in some form are probably con
satisfied many many places around the
universe
even and even within our galaxy uh
i'm not so sure about the emergence of
intelligent life
or the emergence of technological uh
civilizations that that that seems
uh much more much more contingent and
special and
we might it's conceivable to me that
we're the only example
in the galaxy or although
yeah i don't know one way or the other i
i have different opinions on different
days of the week well one of the things
that worries me
in in uh in the spirit of being humble
that our particular kind of intelligence
is not very special so there's all kinds
of different intelligences
and even more broadly there could be
many different
kinds of life yes so the basic
definition and i just had
i think somebody that you know sarah
walker i just had a very long
conversation with her
about even just the very basic question
of trying to define
what is life from a physics perspective
yeah even that question within itself i
think one of the most fundamental
questions
in science and physics and everything is
just
trying to get a hold trying to get some
universal laws around the
ideas of what is life because that kind
of unlocks a bunch of things around
life intelligence consciousness all
those kinds of things
i agree with you in a sense but i think
that's a dangerous question because
the the answer can't be any more precise
than the question
and the uh the the question what is life
kind of assumes that we have a
definition of life and that it's a
natural phenomena that that can be
distinguished
but that really there are edge cases
like viruses and
uh some people would like to say that uh
electrons have consciousness and they
you know
so you can't if you really have fuzzy
concepts
it's uh it's very hard to to reach
precise kinds of scientific answers
but i think there's a very fruitful
question that's
adjacent to it which is has been pursued
in different forms
for quite a while and is now becoming
very sophisticated
in reaching in new directions and that
is
what are the states of matter that are
possible you know so
in high school or grade school you
learn about solid solids liquids and
gases but that really just scratches the
surface
of different ways that are
distinguishable that matter can
form into uh
macroscopically different meaningful
patterns that we call phases
and then there are precise definitions
of what we mean by phases of matter
but then uh and that have been worked
out fruitful
over the decades and we're discovering
new states of matter all the time
and kind of having to work at what we
mean by
matter we're discovering the
capabilities of matter
to organize in interesting ways
and uh
some of them like liquid crystals
are important ingredients of life our
cell membranes are liquid crystals
and that's very important to the way
they work
recently there's been a development in
where we're talking about
uh states of matter that not only
not that are not static but that have
dynamics that have that uh
have characteristic patterns not only in
space but in time
these are called time crystals and
that's that's been a development that's
just in the last decade or so it's
really
really flourishing uh and
so uh is there a state of matter that
cause or
group of states of matter that
corresponds to life
uh maybe but but the answer can't be any
more definite than the question
so i mean i i got to push back on the
the the quite
those are just words i mean i i i
disagree with you the
the the question points to a direction
the answer might be able to be to be
more precise than the question
because because uh just as you're saying
there
there's uh that we could be discovering
certain
characteristics and patterns that are
associated with a certain
type of matter macroscopically speaking
and that that we can then uh be able to
post facto say this is let's
sign the word life well kind of matter i
agree with that completely that that's
that's uh but that's so it's not a
disagreement
it's very frequent in physics that where
in science that
uh words that are in common use gets
get refined and reprocessed into
scientific terms that's happened for
things like force and
energy uh and
so we've in a way we we find out what
the useful definition
is uh or symmetry for instance
and the common usage may be quite
different from the scientific usage but
the scientific usage
is special and takes on a life of its
own and we find out what the
the useful version of it is
uh what the the fruitful version of it
is
so i do think so in that spirit
i think if we uh can
identify states of matter
that or linked states of matter
that can carry on processes of uh
self-reproduction and development
and information processing
we should say we we might be tempted to
classify those
as like things as life yeah well can i
ask you about the craziest one
which is uh the one we know
maybe least about which is consciousness
is it possible that there are certain
kinds of matter would be able to
classify
as um conscious meaning
like the so there's uh the pan cyclists
right with the philosophers who kind of
try to imply that uh all matter has some
degree of consciousness and yeah you can
almost construct like a physics of
consciousness
yes do you um
again we're in such early days of this
but nevertheless it seems useful to talk
about is
is there some sense from a physical
perspective to make sense of
consciousness
again consciousness is uh
imprecise a very imprecise word and
loaded with
uh connotations that i think we should
we
don't want to start a scientific
analysis with that i don't think
uh it's often been
important in science to start with
simple cases
and work up uh consciousness i think
what
most people think of when you talk about
consciousness is okay
i'm what am i doing in the in the world
this is my experience i have a rich
experience rich inner life and
experience of
and uh where is that in the equations
and
i think that's a great question a great
great question and actually i think
i'm gearing up to spend part of the i
mean
to try to address that in coming years
one version of asking that question just
as you said now
is what is the simplest yeah formulation
of
that to study i think i think i'm much
more comfortable with the idea of
studying self-awareness
as opposed to consciousness because that
that sort of gets rid of the mystical
aura of the thing and self-awareness
is uh in simple you know the
i think uh contiguous at least
with ideas about feedback so
if you have a system that looks at its
own state
and responds to it that's a kind of
self-awareness
and more sophisticated versions could be
like
in information processing things
computers that look into their own
internal state and do something about it
and i think that could also be
done in neural nets this is called
recurrent neural nets which are hard to
understand and kind of a frontier of
the the uh uh so i think understanding
those
and gradually building up a kind of
uh profound
ability to un to uh
conceptualize different levels of
self-awareness what do you have to not
know and what do you have to know
and when do you know that you don't know
it or when do you know what do you think
you know that you don't really know
the the these uh i think uh
clarifying those issues when we clarify
those issues and get a rich theory
around uh self-awareness i think
the that will illuminate
the questions about consciousness in a
way that you know scratching your chin
and talking about qualia and blah blah
blah blah
is never going to do well i also have a
different approach to the whole thing so
there's from a robotics perspective you
can engineer
things that exhibit yes qualities of
consciousness without understanding
well well the how things work
and from that perspective you uh
it's like a back door like enter through
the psychology door
precisely the car yeah i think we're on
we're on the same wavelength here i
think that
and let me just add one comment which is
uh i think we should try to understand
consciousness as we experience it
uh in in as
in evolutionary terms and ask ourselves
why why does it happen this thing seems
useful
why is it useful why is it useful
i think we've got a conscious eye watch
here interesting quest thank you siri
okay yeah
get back i'll get back to you later uh
yeah uh um and i think what we're gonna
i'm i'm morally certain that what's
going to emerge from
analyzing recurrent neural nets and
robotic design and advanced computer
design
is that having this kind of
looking at the internal state
in a structured way that
that doesn't look at everything as guys
has it's encapsulated looks at highly
processed information and very selective
and makes
choices without knowing how they're made
there's so there'll also be an
unconscious
i think that that is going to be turn
out to be
really essential to doing efficient
information processing
and that's why it evolved
because it's it's it's it's helpful
in uh because brains come at a high cost
yeah so there has to be there has to be
a good why and there's a reason
yeah they're rare in evolution uh
you and uh big brains are rare in
evolution and they
they come at a big cost you mean if you
you they
they they have high metabolic
demands uh they require
you know very active lifestyle warm
bloodedness
and take away from the
ability to support metabolism of
digestion and so so it's it's uh
it comes at a high cost it has to it has
to pay back
yeah i think it has a lot of value in
social interaction so i
actually i'm spending the rest of the
day today and uh
with uh our friends uh
that are our legged friends in robotic
form at boston dynamics
and i think so
my probably biggest passion is human
robot interaction
and it seems that consciousness from the
perspective of the robot is very useful
to improve the human robot interaction
experience
the first the display of consciousness
but then to me there's a gray area
between the display of consciousness and
consciousness itself
if you think of consciousness from an
evolutionary perspective
it seems like a useful tool in human
communication so yes
um it's certainly well whatever
consciousness it
will turn out to be i think uh
addressing it
through its use yes and working up from
simple cases and also
working up from engineering experience
in trying to do efficient computation
including
efficient management of social
interactions
is going to really shed light on these
questions as i said in a way that
sort of musing abstractly about
consciousness never would
so as i mentioned i talked to sarah
walker and
first of all she says hi spoke very
highly of you one of her concerns about
physics
and physicists and humans is that
we may not fully understand the system
that we're inside of meaning
like there may be limits to the kind of
physics we do
in trying to understand the system of
which we're
part of so like the the observer
is also the observed in in that sense
it seems like the the um
our tools of understanding the world
i mean this is mostly centered around
the questions of what is life
trying to understand the patterns that
uh that are characteristic of life and
intelligence all those kinds of things
um we we're not we're not using the
right tools
because we're in the system is there is
there something that resonates with you
there almost well yeah yes we do have we
we have limitations of course uh
in the amount of information we can
process
uh on the other hand we can get help
from our silicon friends
and we uh we can get help from all kinds
of instruments that make up for for our
perceptual deficits
and uh we have to and we can use
at a conceptual level we can use
different kinds of concepts to address
different kinds of questions so i'm not
sure exactly
what problem she's talking about it's a
problem akin to
an organism living on a in a 2g plane
trying to understand
a three-dimensional world well we can do
that i mean you know we
in fact we you know for practical
purposes most of our experience
is two-dimensional it's hard to move
vertically and yet we've produced
conceptually a three-dimensional
symmetry and in fact
four-dimensional space-time uh so
you know by thinking in appropriate ways
and
using instruments and demand and getting
consistent accounts and rich accounts
we find out what concepts are uh
uh uh necessary and
uh i don't see any end in sight of the
process
or any uh show stoppers because
let me give you an example i mean for
instance uh
uh qcd our theory of the strong
interaction has
nice equations which i helped to
discover what's qcd
quantum chromodynamics so it's our
theory
of the strong interaction the
interaction that is responsible for
nuclear physics so it's the interaction
that governs how quarks and gluons
interact with each other and make
make protons and neutrons and all the
strong the
related particles and among many things
in physics it's one of the
four basic forces of nature as we
presently understand it
uh and
uh so we have beautiful equations which
we can
test in very special circumstances
uh uh using at high high energies at
accelerator so we're
certain that these equations are correct
you know prizes are given for it and so
people try to knock it down and they
can't and yeah they they the
they uh uh but
uh but the situations in which you can
calculate the consequences of these
equations are very limited
so for instance no one has been
able to demonstrate that
this theory which is built on
quarks and gluons which no one that
which you don't observe
actually produces protons and neutrons
and the things you do observe this is
called the problem of confinement
so no one's been able to prove that
analytically in a way that a human can
understand
on the other hand we can take these
equations
to a computer to gigantic computers and
compute
and by god you get the world
from it the so these equations
in a way that we don't
understand in terms of human concepts we
cut we
we can't do the calculations but our
machines can do them
so with the help of what i like to call
our silicon friends and
their their descendants in the future we
can
understand in a different way that
allows us to understand more
but i don't think we'll ever no no human
is ever going to be able to calculus
solve those equations in the same way so
so but but i think that's you know when
we find limitations to
our natural abilities we can
try to find works or workarounds and
sometimes that's appropriate concepts
sometimes it's appropriate instruments
sometimes it's a combination of the two
but i think
uh it's premature to
get defeatist about it i don't see
anything i don't see any
uh any logical
contradiction or paradox or limitation
that that will bring this process to a
halt
well i think the idea is to continue
thinking outside the box in different
directions meaning
just like how the math allows us to
think of multiple dimensions
outside of our perception system uh sort
of
thinking uh um you know coming up with
new tools of mathematics or computation
or
all those kinds of things to to
to to take different perspectives on our
universe
well i'm all for that you know and i i
kind of have even elevated it into a
principle which is of complementarity
following boar that you need different
ways of thinking
even about the same things in order to
do justice to their reality and answer
different kinds of questions about them
i mean we've several times alluded to
the fact that
human beings are hard to understand and
the concepts that
you use to understand human beings if
you want to
prescribe drugs for them or see what's
going to happen if
if they move very fast or get ex
or are exposed to radiation and so that
requires one kind of thinking that's
very
physical uh based
based on the fact that the materials
that we're made out of
on the other hand if you want to
understand how a person's going to
behave in a different kind of situation
you need entirely different concepts
from psychology and
there's nothing wrong with that you can
have different ways of addressing
the same material that are useful for
different purposes right
can you describe this idea which is
fascinating of complementarity a little
bit sort of uh
first of all what uh
state is the principle what is it and
second of all
what are good examples starting from
quantum mechanics you used to mention
psychology
let's talk about this more it's like one
in your new book one of the most
fascinating ideas actually
i think it's a wonderful yeah it's it's
sort of to me it's it's well it's the
culminating chapter of the book and i
think
uh since the whole book is about the big
lessons or big takeaways
from profound understanding of the
physical world that we've understood
that we've achieved uh including that
it's mysterious in some ways
the uh this was the the
the final overarching
uh lesson complementarity and uh
it's a
approach it's so unlike some of these
other things which are just facts about
the world
like the world is both big and small and
different sessions is this
and is is big but we're not small think
the things we talked about earlier
uh and the fact that the universe is
comprehensible and how
complexity could emerge from simplicity
and those things are
uh in some in the broad sense facts
about the world
complementarity is more an attitude
towards the world
encouraged by the facts about the world
and uh it's
the idea the concept of the approach
that
or the realization that uh
it can be appropriate and useful
and inevitable and unavoidable to use
very different descriptions of the same
object or the same system or the same
situation
to answer different kinds of questions
that
may be very different and even
uh mutually uninterpretable immutably
uh incomprehensible
uh but both correct somehow but both
correct and
sources of different kinds of insight
which is so weird
yeah well but it seems to work in so
many cases it works in many cases and i
think
it's uh it's a deep fact about
the world and how we should approach it
its
most rigorous form
where it's actually a theorem if quantum
mechanics is correct
occurs in quantum mechanics where
the primary description of the world
is in terms of wave functions but let's
not talk about the world let's just talk
about a
a particle an electron okay it's it's
it's the primary description of that
electron
is its wave function and the wave
function can be used to
predict where it's going to be
with different if you observe with it'll
be in different places with different
probabilities
or how fast it's moving and it will also
be moving in different ways with
different probabilities that's what
quantum mechanics says
and you can predict either set of
probabilities if you
what's going to happen if i make an
observation
of the position or the velocity
but so the wave function gives you ways
of doing both of those
but to do it to get those predictions
you have to process the wave function in
different ways
you process it one way for position and
in a different way for
momentum and those ways are
mathematically incompatible
it's like you know it's like you have a
stone and you can sculpt it
into a venus de milo or you can sculpt
it into david but you can't do both
you can uh and uh
and that's an example of complementarity
but to answer different kinds of
questions you have to analyze the system
in different ways
that are mutually incompatible
but both valid to answer different kinds
of questions
so in that case it's a theorem but i
think
it's a much more widespread phenomena
that applies to many cases where we
can't prove it as a theorem
but uh it's a piece of wisdom if you
like and then
appears to be a a very important insight
do you uh and if you ignore it you can
get very
confused and uh
misguided do you think this is um
a useful hack for
ideas that we don't fully understand or
is this
somehow a fundamental property of all
or many ideas that you can take
multiple perspectives and they're both
true well i think it's both
those both the answer to all questions
yes that's right
it's not either or it's both it's
paralyzing to think that
that we live in a world that's
fundamentally
like surrounded by complementary ideas
like
uh because it uh we want universe we
somehow want to attach ourselves to
absolute truths
and absolute truths certainly don't like
the idea of
complementarity yes einstein was very
uncomfortable with complementarity
and in a broad sense the famous poor
einstein debates
revolves around this question of whether
the complementarity that
is a foundational feature of quantum
mechanics as we have it
was is uh
a permanent feature of of the universe
and that's our description of nature
and so far quantum mechanics wins
and it's gone from triumph to triumph
whether
complementarity is rock bottom i guess
we're you know
you can never be sure i mean but but uh
it looks awfully good and it's been very
successful and
certainly its complementarity has been
extremely
useful and fruitful in in that domain
uh including you know one of some of
einstein's
attempts to challenge it with
like the famous einstein podolsky rosen
experiment turned out to be
confirmations of
that that uh have have been
uh useful in themselves but so thinking
about these things was fruitful but
not in the way that einstein hoped the
the uh
yeah so so as i said in in the case
of uh quantum mechanics and this
dilemma or dichotomy between processing
the wave function in different ways
it's a theorem they're mutually
incompatible and that the physical
correlate of that is the heisenberg
certainty principle that you can't have
position and momentum
determined at once uh
but uh in other cases like
one that i like to talk like to think
about is or like to
point out as an example is is free will
and determinism
it's much less
of a theorem and more more a uh
more a a kind of uh
way of thinking about things that i
think is
uh reassuring and
avoids a lot of unnecessary quarreling
and confusion the quarreling i'm okay
with
and the confusion i'm okay with i mean
people debate about difficult ideas
but the the question is whether it could
be almost
a fundamental truth i think it is a
fundamental truth
free will is both an illusion
and not yes i think that's correct and i
loaded the reason why people say quantum
mechanics is weird
and complementarity is is is a big part
of that
you know to say that the our actual
whole world is weird
the whole hierarchy of the universe is
weird in this
kind of particular way and
it's it's quite profound but it's also
um
humbling because it's like
we're we're never going to be on sturdy
ground in the way that humans
like to be it's like you have to embrace
that uh
well this this this whole thing is is uh
like unsteady mess it's one of it's one
of many
lessons in humility that that we
uh run into in profound understanding of
the world
i mean uh the copernican revolution was
one
that's that the earth is not the center
of the universe
uh darwinian evolution is another that
uh
humans are not the pinnacle of uh
of uh you know of of
god's creation uh the the uh
uh and the
uh apparent result
of uh uh deep understanding of physical
reality that
the mind emerges from matter and human
there's you know
there's there's no uh no call
on special life forces or souls uh
these are all lessons in humility and
i actually find complementarity
a uh a liberating concept
it's it's a okay you know yeah it is in
a way
uh that is what i remember there's a
there's a story about dr johnson
and he's talking with boswell and
boswell
was they were discussing a sermon that
they both both heard and the
the sort of culmination of of the sermon
was
the the the speaker saying i accept the
universe
and dr johnson said well he damn well
better
and and there's a certain uh there's a
certain joy in accepting the universe
because it's mind expanding
and uh
you know it and to me complementarity
also suggests tolerance
suggests opportunities for understanding
different different understanding things
in different ways that add
add to rather than detract from
uh understanding so uh i think it's it's
an up
it's an opportunity for mind expansion
and
demanding that there's only one way to
think about things
can be very limiting and the free will
one that's a trippy one though i think
to think like i am the decider of my own
actions
and at the same time i'm not is uh
is tricky to think about but it's there
does seem to be some kind of profound
truth in that
i get well i think it is tied up it will
turn out to be tied up when we
understand things better
with these issues of self-awareness and
i think so
and where we get what what we perceive
as making choices what does that really
mean and
what's going on under the hood and
but i'm i'm speculating about a future
understanding that's not in place
at present your sense there will always
be uh
like as you dig into the self-awareness
thing there'll always
be some places where complementarity is
going to show up oh definitely
yeah i mean it will be uh
how should i say there'll be kind of a
god's eye view
which sees everything that's going on
in the computer or the the brain and
then there's the brain's own view
or the or the central processor or
whatever it is that's the
what we call the the the the self the
consciousness
that's all only aware of a very small
part of it and those are very different
those are the the so uh the god's eye
view can be deterministic
while the the the the self view
sees free will and that's i i'm pretty
sure that's how it's going to work out
actually and but as it as it stands free
will
is a concept that we definitely at least
i feel i definitely experience i can
choose to do one thing than another
and other people i think are
sufficiently similar to me that i
i trust that they feel the same way
and it's an essential concept in
psychology and law
and so forth but uh
at the same time i think that mind
emerges from matter
and that there's an alternative
description of matter that's you know up
to subtleties about quantum mechanics
which i don't think are relevant here
uh really is deterministic let me ask
you about some particles
okay first the absurd question almost
like a question that like plato would
ask
what is the smallest thing in the
universe
as far as we know the the
fundamental particles out of which we
build
our most successful description of
nature
are points they have zero they have
don't have
any internal structure that's
they uh so that's as small as can be
to uh so what does that mean
operationally that means
if you that they obey equations that
describe
entities that are singular
concentrations of energy momentum
angular momentum the things that
particles have but localized at
individual points now uh that
mathematical structure is
only revealed partially in the world
because to
to process the wave function in a way
that that that
accesses information about the precise
position of things you have to apply a
lot of energy
and that's not you know we that's an
idealization that you can apply infinite
amount of energy to determine a
precise position but at the mathematical
level
uh we build the world out of particles
that are points
so do they actually exist and what are
we talking about so like oh they exist
so let me ask sort of uh do quarks exist
yes
two electrons exist yes two photons
exist yes
but what does it mean for them to exist
okay so well
the hard answer to that the precise
answer
is that uh we construct the world
out of equations that contain entities
that
uh are reproducible that exist in
vast numbers throughout the universe
that have definite properties of
mass spin
and a few others that
we call electrons and the what what an
electron is is defined
by the equations that it satisfies
theoretically
and we find that there are many many
exemplars of that of that entity
in in the physical world so intellect in
the case of electrons we can
you know isolate them and study them in
individual ones in great detail
and we can check that they all actually
are
identical and
that's why chemistry works and yes so so
so that in that case uh it's very
tangible similarly with photons you can
study them individually they're the
units of light
uh and uh nowadays it's very practical
to study individual photons and
determine their
uh their spin and their other basic
properties and
uh uh and check out the equations in
great detail
for quarks and gluons which are the
other
two main ingredients of uh
our model of matter that's so successful
uh it's a little more complicated
because the quarks and gluons
that appear in our equations don't
appear directly as particles you can
isolate
and study individually they always occur
within bound to what are called bound
states or structures like protons
a proton roughly speaking is composed of
three quarks and a lot of gluons but
we can detect them in a remarkably
direct way actually nowadays
whereas at relatively low energies
uh the behavior of quarks is complicated
at high energies they can prop they can
propagate through space relatively
freely
for a while and we can see their tracks
so ultimately they get recaptured into
protons and other
mesons and funny things but for a short
time
they propagate freely and while that
happens we can
take snapshots and see see their
manifestations
uh this is the actually this kind of
thing is exactly what i got the nobel
prize for
predicting that this would work and
similarly for gluons although
you can't uh you can't isolate them as
individual particles and study them in
the same way we study electrons
say uh you can
use them to as use them theoretically as
entities out of which you
build tangible description tangible
things that we actually do observe uh
but also
you can uh at accelerators at high
energy you can liberate them for brief
periods of time and study wow
and and get convincing evidence that
they
they they leave tracks and then you can
get convincing evidence that they were
there and
and have the properties that that we
wanted them to have can we talk about
asymptotic freedom this very idea that
you won the nobel prize for
yeah so it describes a
very weird effect to me uh
the the weird in the following way so
the
the the you know the way i think of most
forces or interactions the closer you
are
the stronger the effect the the stronger
the force yeah
right with with quarks uh
the closer they are the the less so the
strong interaction
and in fact they basically act like free
particles when they're
very close that's right yes well but
this requires a huge amount of energy
like can you describe me um
why how does this even work
how weird it is proper description
must bring in uh quantum mechanics and
relativity and
it's uh so a proper description
and equations so a proper description
really is is probably
uh more more more than we have time for
and then
uh we require quite a bit of patience on
your part but uh
how does relativity come into play wait
wait
relativity is important because
when when we talk about
trying to think about short distances we
have to think about
very large momenta and very large moment
are connected to very large energy
in relativity and so the connection
between
how things behave at short distances and
how things behave at high energy
uh really is connected through
relativity in
sort of a slightly backhanded way
quantum mechanics indicates that short
to get to analyze short distances
uh you need to bring in probes
that carry a lot of momentum
this again is related to uncertainty
because
uh it's the fact that you have to bring
in a lot of momentum
that interferes with the possibility of
determining
position and momentum at the same time
if you want to determine position
you have to use instruments that bring
in a lot of momentum
and because of that those same
instruments can't also measure momentum
because they're disturbing the momentum
and then the momentum brings in energy
and yeah so
so that there's also the effect that
asymptotic freedom comes from
uh the possibility of spontaneously
making uh quarks and gluons
for short amounts of time that that
fluctuate into existence and out of
existence
uh and uh the
fact that that can be done with a very
little amount of energy
and and uncertainty and energy
translates into uncertainty in time so
if you do that for a short time you can
do that uh
well it's all it comes in a package and
you can
you can so uh i told you it would take a
while to really uh to really explain
but the uh but but
the results can be understood i mean we
can state the results
uh pretty simply i think so uh
in everyday life we do encounter some
forces that increase with distance and
kind of
turn off at short distances that's the
way rubber bands work if you think about
it or
you if you pull them hard they they
resist and
but but they get flabby if if if the
rubber band is not
not pulled uh and so there are
that can happen uh in the physical world
but what's what's really difficult is to
see how that could be a fundamental
force that's consistent with everything
else we know
and that that's what asymptotic freedom
is it says that uh
there are particular there's a very
particular kind of
fundamental force that involves special
particles called gluons with very
special properties
that uh enables that kind of behavior so
ex there were experiments at the time we
did our work there were experimental
indications
that quarks and gluons
did have this kind of property but uh
there were no equations that were
capable of
capturing it and we found the equations
and showed how they work and showed how
they that they were
basically unique and this led to a
complete theory of how the strong
interaction works which is
the quantum chromodynamics uh we
mentioned earlier
and so uh
so that's the phenomenon that that
quarks
and gluons interact very very weakly
when they're close together
that's connected through relativity with
the fact that they
also interact very very weakly at high
energies
so if you have so at high energies
the simplicity of the fundamental
interaction gets revealed
you know at the time we did our work the
clues were very subtle
but nowadays at hot at what are now high
energy accelerators it's all obvious
so we would have had a much well
somebody would have had a much easier
time
20 years later looking at the data you
can sort of see the quarks and gluons
as i mentioned they leave these short
tracks that uh it would have been much
much easier but but
we from fundamental from indirect clues
we were able to piece together enough
to make that behavior a prediction
rather than a
post-diction right so it becomes obvious
at high energies
it becomes very obvious when when we
first did this work
it was uh frontiers of high energy
physics
and at big international conferences
there would always be sessions on
testing qcd and whether these
whether this proposed description of the
strong interaction was in fact correct
and so forth
and it was very exciting they were big
but
nowadays the same kind of work
but much more precise with
calculations to more accuracy and
experiments that are much
more uh precise
and comparisons that are very precise uh
now it's called calculating backgrounds
because
it's because people take this for
granted and one of you and want to
see deviations from the theory which
would be which would be
the new discoveries yeah the cutting
edge becomes the foundation of
foundation becomes boring yes
uh uh is is there some
for basic explanation purposes is there
something to be said about
uh strong interactions in the context of
the
the strong nuclear force for the for the
attraction between
protons yeah well the neutrons versus
the
the interaction between quarks within
protons
well quarks and gluons have the same
relation
basically to nuclear physics as
electrons and photons have to atomic and
molecular physics
so atoms and photons
are the dynamic entities that really
come into play in chemistry and
atomic physics of course you have to add
the atomic nuclei but those are
small and relatively inert really the
dynamical
part and you know for for most purposes
of chemistry you just say
you have this tiny little nucleus which
this which
qcd gives you don't worry about it it
just it's there
the real the real action is the
electrons moving around and exchanging
and things like that
uh the uh but okay but we wanted to
understand
the nucleus too and uh
so atoms base are sort of quantum
mechanical clouds of electrons
held together by electrical forces which
is photons and then this radiation which
is also
another aspect of photons that's where
all the fun happens is the electrons and
the photons
yeah that's right and the nuclei the
nucleus are kind of the
the uh well they're necessary they give
the positive charge
and most of the mass of matter
but they don't since
since they're so heavy they don't move
very much in chemistry
and uh uh i'm oversimplifying
drastically they're not contributing
much of the interaction and
for most purposes in chemistry you can
just idealize them as concentrations of
positive mass and charge that
that are uh you don't have to look
inside
but people are curious what what's
inside what really
and and uh that and that was a big thing
on the agenda of 20th century physics
starting in the
19 well starting with the 20th century
and
unfolding throughout of trying to
understand
what forces held the atomic nucleus
together what it was and so
uh anyway the
the emerge the story that emerges from
qcd
is that very similar to the way
that well broadly similar to the way
that uh
uh clouds of electrons held together by
electrical forces
uh give you atoms and ultimately
molecules uh protons
and neutrons are like atoms
made now out of quarks quark clouds held
together by gluons which are
like like like the photons that that
will give the electric forces
but this is giving a different force the
strong force
and uh and the residual forces between
protons and neutrons that uh
are left over from their basic binding
are like the residual forces between
atoms that give molecules but
in the case of protons and neutrons it
gives you atomic nuclei
so again for definitional purposes uh
qcd
quantum chromodynamics is basically the
physics
of strong interaction yeah we understand
we now would unders which
i think most physicists would would say
it's the theory of
quarks and gluons and how they interact
but it's a very precise and i think it's
fair to say very beautiful
theory based on mathematical symmetry of
a high
order uh and another thing that's
beautiful about it is
that it's kind of
in the same family as electrodynamics
the conceptual structure of this of the
equations are very similar they're based
on having
particles that respond to charge in a
very symmetric way
in the case of electrodynamics it's
photons that respond to electric charge
in the case of
quantum chromodynamics there are three
kinds of charge that we call colors
but they're nothing like colors they
really are like different kinds of
charge
but they rhyme with the same kind of uh
like it's similar kind of dynamics
similar kind of dynamics i call i say i
like to say that qcd is like
qed on steroids and instead of one
photon you have eight gluons instead of
one charge you have three color charges
but there's a strong family resemblance
but the context in which uh qcd does its
thing is it's
it's much higher energies like that's
where it comes to wealth
it's a stronger force so that to
access how it's works and kind of pry
things apart you have to inject more
energy
and so that that gives us um
in some sense a hint of uh how things
were in the earlier universe yeah well
in that regard
asymptotic freedom is a tremendous
blessing because it means
things get simpler at high energy and
the universe was born free
born free that's very very good yes
chris was born so
so in atomic physics i mean a similar
thing happens in the theory of stars
stars are hot enough that uh the
interactions between electrons and
photons are
they're they're liberated they don't
form atoms anymore they make a plasma
which in some ways is simpler to
understand
you don't have complicated chemistry and
in the early universe according to qcd
similarly atomic nuclei dissolved into
the constituent
quarks and gluons which are moving
around very fast and
interacting in relatively simple ways
and so this
uh this opened up the early universe to
scientific
calculation can i ask you about some
other weird particles that make up our
universe
what are axions and what is the strong
cp problem
okay so uh let me start with what the
strong cp problem is
uh first of all well charge con
c is charge conjugation which is the
transformation uh the notional
transformation if you like that changes
all particles into their anti-particles
and the concept of seek
symmetry charge conjugation symmetry is
that if you do that
you find the same laws would work
so the laws are symmetric if
the behavior that particles exhibit is
the same as the part
as the behavior you get with all their
anti-particles
uh then p is parity
which is uh also called spatial
inversion
it's basically looking at a mirror
universe
and saying that the laws that are obeyed
in a mirror universe when you look
the the mirror images obey the same laws
as the
as the sources of their images there's
no way of telling left
right for instance that the laws don't
distinguish between left and right
uh now in the mid 20th century
people discovered that both of those are
not quite true
that really the the equation that the
mirror universe
this the universe that's that you see
in a mirror is not
going to obey the same laws as the as
the
the universe that that that we actually
exhib
uh and interpret you could you would be
able to tell if you
did the right kind of experiments which
was the mirror and which was the real
thing
uh anyway that that's the parody and
they show that
doesn't necessarily hold it doesn't
quite hold and that that oh
that and examining uh
what the exceptions are turned out to be
to lead to all kinds of insight about
the nature of fundamental interactions
especially properties of neutrinos and
the weak interaction it's a long story
but it's a very it's a so you just
define the c
and the p the conjugation the charge
conjugation now that i've done that i
want to
what's the problem shove them off okay
great
because it's easier to talk about t
which is time reversal symmetry
we have very good reasons to think uh
cpt is a an accurate
symmetry of nature it's on the same
level as relativity and quantum
mechanics basically so
that better be true uh so it's
symmetric when you when you do
conjugation parity in time
and time and space reversal if you do
all three
then you get the same physical
consequences now
so but that means that cp is equivalent
to t
but but what's observed in the world is
that t is not quite an accurate symmetry
of nature
either so most phenomena
uh of at the fundamental level
so interactions among elementary
particles and the basic
gravitational interaction uh
if you ran them backwards in time
you'd get the same laws so if
ag again going unless this time we don't
talk about a
a mirror but we talk about a movie if
you take a movie
and then run it backwards
that's the time reversal uh it's good to
think about a mirror
in time yeah it's like a mirror in time
if you
uh if you run run the movie backwards
it would look very strange if you were
looking at complicated objects and
uh you know a charlie chaplin movie or
whatever
they it would look very strange if you
ran it backwards in time
but at the level of basic interactions
if you
were able to look at the atoms and the
and the quarks involved
they would obey the same laws they do a
very good approximation but not exactly
so you this is not exactly that means
you could tell you could tell
but you'd have to do very very subtle
experiments with at high energy
accelerators
to take a movie that looked different
when you ran it backwards
this was a discovery by uh
two great physicists named cronin and
jim cronin
and val fitch in the uh
in the mid-1960s previous to that over
all the centuries of development of
physics with all this precise laws
they did seem to have this gratuitous
property
that they look the same if you run the
equations backwards
it's kind of an embarrassing property
actually because
life isn't like that so empirical
reality does not have this imagery
in any obvious way and yet the laws did
it's almost like the laws of physics are
missing something fundamental about life
if if if it holds that property right
well i mean that's
that's the embarrassing nature it's it's
yeah it's well people
worked hard and at what's
this was a problem that's thought to
belong to the foundations of statistical
mechanics or the
foundations of thermodynamics to
understand
how behavior which is
grossly not symmetric
with respect to reversing the direction
of time in large objects
how that can emerge from equations which
are
symmetric with respect to changing the
direction of time to a very good
approximation
and that's that's still an interesting
endeavor that's that's
that's interesting and uh actually it's
an exciting frontier of physics now to
sort of explore the boundary
between when that's true and when it's
not true when you get to smaller objects
uh and exceptions like time crystals or
uh
i definitely have to ask if i'll time
crystals in a second here but
so the cp problem and t so there's
lost all of these we're in danger of
infinite regress but we'll
convert soon so can't possibly be
turtles all the way down
we're going to get to the bottom turtle
so so so it became
so it it got to be a real i mean it's a
really puzzling thing
uh why the laws should have this very
odd property that we don't need
and in fact it's kind of an
embarrassment
in addressing empirical reality but it
seemed to be
almost it seemed to be exactly true for
a long time and then
uh almost true and
and in way almost true was even is more
disturbing than exactly true because
exactly true it could have been just a
fundamental feature of the world and you
know at some level you just have to take
it as it is and if it's
if it's a beautiful easily articulatable
regularity you could say that okay
that's a that's
fine as a fundamental law of nature but
to say that it's approximately true but
not exactly that's that's that's right
that's weird so uh and then
so there was great progress in
uh the late part of the 20th century
uh in getting to an understanding of
fundamental interactions in general
that shed light on this issue uh
it turns out that the prince
basic principles of relativity and
quantum mechanics plus
the kind of high degree of symmetry that
we
found the so-called gage symmetry that
characterizes the fundamental
interactions when you put all that
together
it's a very very constraining framework
and it has some indirect consequences
because the possible interactions are so
constrained and one of the indirect
consequences
is that the possibilities for
violating the symmetry between forwards
and backwards in time are very limited
there are basically only two
and one of them occurs and leads to a
very rich theory that explains the
cronin fish experiment and a lot of
things that have been done subsequently
has been used to
make all kinds of successful predictions
so that's
that's turned out to be a very rich
interaction it's esoteric and the
effects are
only show up at accelerators and are
small and so on but they might have been
very important in the early universe and
lead to them be connected to the
asymmetry between matter and anti-matter
in the present universe and so but
that's a that's another digression
the the point is that uh that was fine
that was a triumph
to say that there was one possible kind
of interaction that would violate
time reversal symmetry and sure enough
there it is and
but the other kind
doesn't occur so we still got a problem
why
doesn't it occur uh so but
we're so we're close to really finally
understanding this profound gratuitous
feature of the world
that is almost but not quite
symmetric under reversing the direction
of time but but not quite there
and to get to understand that last
bit is a challenging frontier of physics
today
and we have a promising proposal for how
it works
which is a kind of theory of evolution
so there's this possible
interaction which we call a coupling and
there's a numerical quantity
that tells us how strong that is and
traditionally in physics we think of
these kinds of numerical
quantities as constants of nature
that you just have to put them in
right from experiment uh they have a
certain value and that that's it and you
know
who am i to question what god do they
just can't
well they seem to be just constantly uh
but in this case
it's been fruitful to think
and work out a theory where
that strength of interaction
[Music]
is actually not a constant it's a
fun it's a field it's a uh it's a
fields are the fundamental ingredients
of modern physics like
there's an electron field there's a
photon field which is also called the
electromagnetic field and so
every all of these particles are
manifestations of different fields
and uh there could be a field
something that depends on space and time
so a dynamical entity
instead of just a constant here
and if you do things in a nice
way that's very symmetric very much
suggested
aesthetically by the theory uh but but
the theory we do have
then you find that you get
a field which
as it evolves from the early universe
settles down to a value
that's just right
to make the laws very nearly
exact invariant or symmetric with
respect to reversal of time it might
appear as a constant but it's actually a
field that evolved over time it evolved
over time
okay but when you examine this proposal
in detail you find that it hasn't quite
settled down to exactly zero there it's
still
the the field is still moving around a
little bit
and because the motion is so
uh the motion is so difficult
the the material is so rigid and this
material that fills all the field that
fills those spaces so rich
even small amounts of motion can involve
lots of energy
and that and that energy takes the form
of uh particles fields of fields that
are in motion are always associated with
particles
and those are the axions and if you
calculate how much
energy is in these residual oscillations
these this axion gas that fills all the
universe if this fundamental theory is
correct
you get just the right amount
to make the dark matter that astronomers
want and it has
just the right properties so i'd love to
believe that
so that might be a thing that unlocks uh
might be the key to understanding dark
matter yeah i'd like to think so
and many many physicists are coming
around to this point of view which
i've been a voice in the wilderness i
was a voice in the wilderness
for a long time but now now it's become
very popular maybe even dominant
so almost like so this axion
particle slash field would be the thing
that explains
dark matter it explained yeah would
solve this fundamental question
of finally of why the laws are
almost but not quite exactly
the same if you run them backwards in
time and and then
seemingly in a totally different
conceptual universe
it would also uh provide unders give us
an understanding of of the dark matter
that's not what it was
designed for and the theory wasn't
wasn't proposed with that in mind
but when you work out the equations
that's what you get that's always a good
sign
yeah actually uh i i think i vaguely
read
uh somewhere that there may be early
experimental validation
of uh uh of axion is that uh
am i am i reading the wrong well there
have been quite a few false alarms and i
think there are some of them still
i mean people desperately want to find
this thing and
uh but i don't think i i i don't think
any of them are convincing at this point
but there are very ambitious
experiments and kind of new
you have to design new kinds of antennas
that are capable of detecting
these predicted particles and it's it's
very difficult they interact very very
weakly if
it were easy it would have been done
already but
but i think there's good hope that we
can get down to the required sensitivity
and actually test whether these ideas
are right
[Music]
in coming years or maybe decades
and then understand one of the big
mysteries like literally big in terms of
uh
its fraction of the universe is dark
matter yes
let me ask you about you mentioned a few
times time crystals
yeah um what are they these things are
it's a very beautiful idea when we start
to um
treat space and time as
a similar frameworks yes
right physical phenomena right that's
what motivated it what are
first of all what are crystals yeah and
what time crystals okay so
crystals are orderly arrangements of
uh atoms in space and
many materials if you cool them down
gently
will form crystals and so we say
that that's uh a spun a state of matter
that forms spontaneously and
uh an important feature of that state of
matter
is that the end result the crystal
uh has less
symmetry than the equations that give
rise to the crystal
so the equations the basic equations of
physics
are the same if you uh move a little bit
so you can move they're homogeneous but
crystals aren't the atoms are in
particular
place so though they have less symmetry
uh
and time crystals are the same thing in
time basically
you but of course it's not so it's not
positions of atoms
but it's ordering uh orderly behavior
uh that certain states of matter uh
will arrange themselves into
spontaneously if you do them
if you if you treat them gently and let
them do what they want to do
but indeed repeat in that same way
indefinitely
that's the crystalline form you can also
have uh
time liquids or you can have all kinds
of other states of matter you don't have
space-time crystals where
the pattern only repeats if uh with each
step of time you also move at a certain
a certain direction in space so so yeah
so but it's so
it's basically it's states of matter
that uh oh base
that display structure in time
spontaneously
so here's here's the difference when it
happens in time
uh it sure looks a lot like
it's motion and if it repeats
indefinitely it sure looks a lot like
perpetual motion
yeah like uh looks like free lunch
i was told that there's no such thing as
free lunch does
does this violate laws of thermodynamics
uh
no but it requires a critical
examination of the
laws of thermodynamics i mean let me let
me say on background that the laws of
thermodynamics
are not the not fundamental laws of
physics there are things we prove
under certain circumstances emerge from
the fundamental laws of physics
right they're not we don't posit them
separately they're
meant to be deduced and they can be
deduced under limited circumstances but
not necessarily
universally and we found finding some of
the subtleties and
sort of accept edge cases uh where they
don't
apply in a straightforward way
and this is one uh so
time crystals do obey do have this
structure in time but it's not a free
lunch
because although in a sense things are
moving uh they're they're already doing
what they want to do
they're in there so if if you want to
extract
energy from it you're going to be foiled
because there's no
spare energy there you uh
it's or so you you can add energy to it
and kind of disturb it
but but you can't extract energy
from this motion because it's gonna it
wants to do that's the lowest energy
configuration that there is so you can
you can't get
further energy out of it so in theory i
guess perpetual motion
uh you would be able to extract energy
from it yeah
if such a thing was to be created you
could then milk it for energy well
what's usually meant in the literature
of perpetual motion
is a kind of macroscopic motion that you
could extract
energy from and and somehow it would
crank back up right that's that's not
the case here if you want to extract
energy uh this motion is
is not something you can extract energy
from if you
intervene in the behavior you can
uh change it but only by injecting
energy not not by taking away energy
you mentioned that a theory of
everything
may be quite difficult to come by a
theory of everything broadly defined
meaning like truly a theory of
everything
but let's look at a more narrow theory
of everything which is that
what the way it's used in often in
physics
is a a theory that unifies
our current uh
laws of physics general relativity
quantum field theory df thoughts
on this dream of a of a theory of
everything in physics
how close are we is there any promising
ideas out there in your view
well it would be nice to have it would
be aesthetically pleasing
uh will be useful no probably not
well i'm i shouldn't no it's dangerous
to say
that but uh probably not i think we
not not in certainly not in the uh
foreseeable future
uh maybe to understand black holes yeah
but that's
that's yes maybe to understand black
holes but
that's not useful and
and well not only i mean only to
understand
it's it's it's worse of course you know
it's not useful in the sense that we're
not going to be
basing any technology any time soon on
black holes
but it's it's more severe than that i
would say it's that
the kinds of questions about black holes
that we can't answer within the
framework of existing theory
are ones that are not
going to be susceptible to astronomical
observation
in the foreseeable future they're
questions about
very very small black holes when
when quantum effects come into play or
uh so that black holes are
you know not not black holes they're
they're they're they're emitting hawk
this discovery of hawking called hawking
radiation
which for astronomical black holes is a
tiny
tiny effect that's no one have no one
has ever observed it's a prediction
that's never
been changed like supermassive black
holes that doesn't apply no
no the the predicted rate of radiation
from those black holes is so tiny that
it's absolutely unobservable and is
overwhelmed by all kinds of other
effects
uh so uh
so it's not practical in the sense of
technology it's not even practical
in the sense of uh application to
astronomy
we our existing theory of
uh general relativity and quantum theory
and our theory of the the different
fundamental forces is perfectly adequate
to
all prep all problems of
technology for sure
and almost all
problems of astrophysics and
cosmology that appear except
with the with the notable exception of
the
extremely early universe if you want to
ask what happened before the big bang or
what happened right at the big bang
which would be a great thing to
understand of course uh
yes we don't but but what about the
engineering question
so if we look at space travel so
uh i think you've spoken with him uh
eric weinstein
really um uh you know he says
things like we want to get off this
planet his intuition is
almost a motivator for the engineering
project
of space exploration in order for us to
crack this problem
of becoming a multi-planetary species we
have to solve the physics problem his
intuition is like if we figure out this
what he calls the source code which is
like
like like like a theory of everything
might give us clues
on how to start hacking the fabric of
reality
like getting shortcuts right it might i
can't say that you know
i can't say that it won't but i can say
that
in the 1970s and early 1980s
we achieved
huge steps in understanding matter
qcd much better understanding of the
weak interaction
much under better understanding of
quantum mechanics in general
and it's had minimal uh minimal impact
on time on rocket design
unprecedented on rocket design on
anything any technology
whatsoever and now we're talking about
much more esoteric things
and since i don't know what they are i
can't say for sure that they won't
affect technology but i'm very very
skeptical that
they would affect technology the uh uh
the because you know to access them you
need to
very exotic circumstances to make new
kinds of particles with high energy you
need accelerators that are
you know it's very expensive and you
don't produce many many of them and so
forth you know
it's just uh it's a pipe dream i think
yeah about space exploration
yes i'm not sure exactly what he has in
mind and
but uh to me uh
it's more a problem of of
something between biology and
i think human bodies are not well
adapted
to space even mars
or even you know which is the closest
thing to a kind of
human environment that we're going to
find anywhere close by
uh very very difficult to maintain
humans on mars
uh and gonna be you know very expensive
and very you know
very unstable and but i think the pros
however uh if we
take a broader view of what it means to
bring human civilization
outside of the earth if we're satisfied
with
you know sending minds out there that we
can
converse with and actuators and that
that we can in uh uh manipulate and
sensors that we can get feedback from i
think that's
that's where it's at and for sure i
think that's so much
so much more realistic and uh
and i think that that's the long-term
future of uh
the space exploration it's not hauling
human bodies all over the place and
that's that's that's just silly but
it's possible that it's human bodies um
so like you said it's a biology problem
what's possible is that um we extend
human lifespan
in some way just we have to look at a
bigger picture it could be just like
you're saying
by sending robots with actuators and
kind of extending the the our limbs
but it could also be extending some
aspect of our minds of information
and it could be cyborgs it could be uh
it could be
no we're talking it could be you know it
could
it could be uh human brains or
cells that realize something like human
brain architecture
uh within uh
within artificial environments you know
shells if you like
that that are more adapted to the
conditions of space
and uh that yeah so that that's entirely
man machine hybrids
as well as sort of remote uh
uh outposts that we can communicate with
i think yeah i think those those will
happen
and uh yeah yeah to me there's some
sense in which
as opposed to understanding the physics
of
the the the the fundamental fabric of
the universe
i think getting to the physics of life
the physics of intelligence the physics
of consciousness
will the physics of information uh
that that that brings
from which life emerges that will allow
us to do space exploration
yeah well i think physics in the larger
sense has a lot to contribute here
not the physics of finding fundamental
new laws in the sense of
uh you know another quark or axions even
physics in the sense of you know physics
has a lot of experience
in analyzing complex situations and
analyzing new states of matter and
devising new kinds of instruments
that do clever things we you know the
the physics in that sense has enormous
amounts to contribute
to uh this kind of endeavor
but i don't think that looking for
a so-called theory of any everything has
much
to do with it at all what advice would
you give
to a young person today
with a bit of fire in their eyes high
school student college student
thinking about what to do with their
life maybe advice about
career or bigger advice about life in
general
well first read fundamentals because
there i've tried
i've tried to to uh give some coherent
uh deep advice that's the fundamentals
ten keys
to reality by train cool check so that's
a good place available
everywhere if you want to learn but i
can tell you
uh the uh is there an audiobook
yes there is an audio book that's
awesome yeah i think
it's like i can give three pieces of
wise advice
that i think are generally applicable
one is to cast a wide net
to really look around and see
what looks promising what catches your
imagination
uh and
and promise yeah and those you have to
balance those two things you can have
things that catch your imagination but
don't look promising in the sense that
the questions aren't ripe
or uh but and and things that you
in part of what makes things uh
attractive
is that whether you thought you liked
them or not is this if you can see that
there's ferment and new ideas coming up
that become that's attractive in itself
so uh when i started out i thought i was
and when i was an undergraduate i
intended to study philosophy or
questions of how mind emerges from
matter but
i thought that wasn't really right
timing isn't right yeah the ripe was the
timing wasn't right for the kind of
mathematical thinking and
conceptualization that i really enjoy
and good at
but uh so that that's one thing cast a
wide net look around
uh and that's that's
a pretty easy thing to do today because
because of the internet you can look
you can look at all kinds of things you
have to be careful though because
there's a lot of crap
also but uh you you know you you can
sort of tell the difference if you
if you do a little digging uh the the uh
so don't don't don't settle on just you
know what your thesis advisor tells you
to do or what your teacher tells you to
do look for yourself and and and
get a sense of what what what seems
promising
uh not what seemed promising 10 years
ago or
the uh so that's one
uh another thing is to
is kind of complementary to that well
they're all complimentary
complementary to that uh is to read
history and read the masters of the
history of ideas and masters of ideas i
benefited enormously from as
as in early in my career from reading
in physics einstein
in the original and feynman's lectures
as they were coming out
and darwin you know these
you can you can learn what it in galileo
you can learn
what it is to wrestle with difficult
ideas and how great minds did that you
can learn a lot about
uh style how how to ex write your ideas
up and
express them in in clear ways
and also just just a couple that with uh
i also enjoy reading biographies
and biographies yes similarly right like
so it gives you the context
the context of the human being that
created those right and
brings it down to earth in the sense
that you know it was really human beings
who did this it's not
uh and and they made mistakes and
yeah uh i also you know i also got
inspiration from bertrand russell who's
a big hero and h.g
wells and yeah so uh read read the
masters
make contact with great minds and when
you are
sort of narrowing down on a subject
learn about the history of the subject
because
that really puts in context what you're
trying to do and
and also gives a sense of community and
grandeur to the whole enterprise
uh and then the third piece of advice is
complementary to both those which is
sort of
to uh to get
the basics under control as soon as
possible
so if you want to do theoretical work in
science
you know you you you have to learn
calculus multivariable calculus complex
variables group theory
nowadays you have to be highly computer
literate
uh if you want to do experimental work
you also have to be computer literate
then you have to learn about electronics
and
optics and instruments and so so get
that
under control as soon as possible
because it's like learning a language uh
to do
to to produce great works and express
yourself fluently and with confidence
uh it should be your native language
these things should be like your native
language so you're not you're not
wondering
um what is a derivative this is just
part of your
you know part it's it's uh it's in your
bones so to speak you know
and the sooner that you can do that then
the the better so those all those things
can be done in parallel and should be
you've accomplished some incredible
things in your life but
uh the sad thing about this
thing we have is it ends uh
do you um do you think about your
mortality
are you afraid of death uh well
well afraid is the wrong way i mean uh
let's define things i wish it weren't
gonna happen
and i'd like to but uh uh do you think
about it
i say occasionally i think about well i
think about it very operationally in the
sense that
uh there's always a trade-off between
exploration and exploitation this is a
classic subject in computer science
actually in machine learning
uh that when you're in an unusual
circumstance you you want to explore to
see what
what the landscape is and what the
gathered data
but then at some point you want to use
that
make decide make choices and say this is
what i'm going to do and exploit the
knowledge you've accumulated
and uh the longer
the period of exploitation you
anticipate
the more exploration you should do in
new directions
and so for me i've had to sort of adjust
the balance of
exploration and uh uh
exploitation and that said you've
explored quite a lot
yeah well i i'm still i haven't shut off
the exploitation at all i'm still hoping
the exploration right i'm still hoping
for 10 or 15 years of top flight
performance but
the uh
several years ago now when i was 50
years old
i i was at the institute for advanced
study and my office was right under
freeman dyson's office and we were kind
of friendly and
uh and you know he found out it was my
my 50th birthday and said
congratulations and uh you should feel
liberated because
no one expects much of a 50 year old
theoretical physicist
and he and he obviously had felt
liberated by uh
by by reaching a certain age and yeah
there is something to that
uh i fee you know i feel i don't have to
catch i don't have to
keep in touch with the latest
hypertechnical developments in particle
physics or string theory or so
like uh because i'm not gonna i'm really
not gonna
be exploiting that i but i but but where
i am exploring
uh in these directions of machine
learning and
and things like that and and but then
but i'm also concentrating
within physics on exploiting directions
that i've already established and the
laws that we already have
and doing things like uh
i'm very actively involved in trying to
design
helping people experimentalists and uh
engineers even to design antennas that
are capable of
detecting axions so there and that's
there we're deep in the exploitation
stage it's not a matter of finding the
new laws but of
really you know using the laws we have
to to
to kind of finish the story off so so
it's complicated but but but
but i'm you know i'm very happy with my
life right now and uh
i'm enjoying it and i don't want to
cloud that by
thinking too much that that it's uh
going to come to an end
you know it's a gift i didn't earn is
there a good
thing to say about why
this gift that you've gotten and didn't
deserve is so damn enjoyable
so like what's the meaning of this thing
of life
to me interacting with people i love
my family and i have a very wide circle
of friends now and i'm
trying to produce some institutions that
will survive me
as well as my as the work and
and it's just it's how should i say
it's a positive feedback work
loop when you do something and if
people appreciate it and and then you
want to do more and they
get rewarded and it's just uh how should
i say this is another gift that i didn't
earn and don't understand but i
i have a dopamine system and
uh yeah i'm happy to use it and
it seems to get energized by uh
by the creative process but yeah process
inspiration very much so
and all of that started from the
little fluctuations
[Laughter]
shortly after the big bang frank well
whatever the those initial conditions
and fluctuation did that created you
i'm glad they did this is uh thank you
for all the work you've done
for the many people you've inspired for
the many of the billion
most of your ideas were pretty useless
of the bill several billions
as it is for all humans but uh you had
quite a few
truly special ideas and uh thank you for
bringing those to the world and thank
you for wasting your valuable time with
me today
it's truly enough it's been a joy and i
hope people uh
enjoy it and and and i think you know
the kind of mind expansion that i've
enjoyed
by interacting with physical reality
at this deep level i think can be
conveyed to and
enjoyed by many many people and that's i
that's one of my missions in life
thanks for listening to this
conversation with frank wilcheck and
thank you to
the information netsuite expressvpn
blinkist and eight sleep check them out
in the description to support this
podcast
and now let me leave you with some words
from albert einstein
nothing happens until something moves
thanks for listening and hope to see you
next time