(logo reverberates) - It's always very special
to stand or address the Royal Institution. For a physicist, one always
thinks back to Michael Faraday. This is a book that I treasure
his Christmas lectures about the natural history of a candle, and it makes great reading even today and I think if Faraday were alive today, he probably would not
wanna talk about candles, but he might give a heck of a cooking show about the chemistry of
cooking and especially microwave cooking, which
is based on his work. In any case, Sir Michael,
(laughs) this is for you. In the book fundamentals,
I really went back and thought about the
questions that motivated me to get into science in the first place, the kind of philosophical questions, what is the nature? What does it all mean? What is the nature of reality? The kinds of things that teenagers ask and that in the everyday work of science, kind of are in the background,
but over the course of my career, I do feel I've learned a lot and it was time to share and
also bring it all into clarity in my own mind, and so
an alternative title and the title of tonight's
lecture would be, What Reality Has Taught Me. So I wanted to show you some
of the themes, the main themes that emerge from the fundamental
understanding of reality, at least in my experience. So, one lesson that
one learns is humility. This is a familiar picture
of, perhaps to some of you, of the earth from the surface of the moon, and from the moon, the
earth looks very beautiful, that the sky, you'll notice is black because there's no atmosphere,
so it's very dramatic and the earth itself is
reflective and patterned, so it's beautiful, but the
main thing you would notice is that it's really small (laughs). It appears as just a little bit
larger than the moon appears in our sky, the earth would
appear in the moon's sky. And of course, the moon
is our closest neighbor in the solar system. The solar system as a whole is much larger and the solar system is a minuscule part of our Milky Way galaxy. The Milky Way galaxy
contains billions of stars like the sun, and then on top of that, when you look out with
a deep space telescope, with the Hubble Space Telescope,
this is a very small part of the sky and what you
see is that if you look with penetrating eyes
deep into the universe, you see a whole sky
full of not just stars, but whole galaxies. Each of these extended objects
is a galaxy and many of them are equal to, or greater
than the Milky Way in terms of the amount of mass and the number of stars they contain. So, all the struggles of
mankind, all the struggles of daily life are taking
place in a very, very small part of the universe and
that's a cause for humility. As for space, so also for
time, one way of bringing that down to proportions
that we can understand is to map cosmic time in a linear fashion, just by rescaling it
onto a year of the time we can comprehend, one
year, cosmic time back to the Big Bang is 13.8 billion years, so if we count that as January 1st, at first it's a very hot
and inhospitable place, and sort of uniformly lit up,
very nearly uniformly bright like the inside of a neon
light, but then things come down a little bit into separate
bodies, and the first signals of that we see are gamma-ray
bursts on January 22nd, galaxies start to form, our
own galaxy is not the first, by any means, not even
in the first generation, it's on the 16th of March
and earth and something like the form we know it
is already taking us deep into the fall. 4.4 billion years is the
oldest rocks on earth and that gives a pretty good indication of when the earth cooled
down, became solid and was a place where life
could possibly maintain itself. And sure enough, in a few
days on this cosmic scale, life did emerge, but
that's already very simple forms of life in 14th of September. I won't go through this whole history, but just to note that God
gave us a Christmas present on the 25th by wiping out
the dinosaurs (laughs) rough, But beyond that it's sort
of right on the border between the 25th and 26th, and
human history as we know it, I'm sorry, the dinosaurs
arose on Christmas and were wiped out on
the last day of the year, and it's only then that mammals snuck out from their hiding places
and their nocturnal ways and human history is
compressed well within the last day and a half
of this cosmic history. So that's plenty of reason for humility if you just judge our
significance in the universe, in terms of how much space we occupy and how much time we
survive as individuals, or as all of humanity. On the other hand, there's
good reason for chutzpah. Chutzpah is a word that may
not be universally familiar. It's a word from Yiddish
that means audacity. So it means (mumbles)
for insolence or cheek, I guess is the British
word that corresponds and there's plenty of
reason for chutzpah too and chutzpah has been a
very successful approach to the universe. And it has an objective basis. This is a sketch of
something each of us has within our skulls. This is the hippocampus,
sketched by the great neuroanatomist, Ramón y Cajal. The human hippocampus is
where short-term memories are processed into long-term memories. It's also the place where a
lot of our sense of orientation and position in space is housed. So it's a very powerful
little processing unit inside our brains. You can see it has a regular structure with many, many, many components. In fact, this method of
staining that was used to make the hippocampus
look like this, but I mean, the way Ramón y Cajal could
get an image of the hippocampus that he could sketch, that
wasn't just black on black, so much complexity that
there there's nothing to see is first of all, by taking
a very, very thin slice, and secondly, by applying
a dye which stains approximately one in 1000 cells. So, the complexity of this,
if you included more layers and didn't select only one in
1000 cells, you can imagine, and even as it is, you
see that within ourselves, we have enormous resources. So we are small compared to the universe, but we are large compared to what it takes to have complex patterns and process them dynamically in time. So, in that sense, Walt Whitman was right that he contains multitudes. And, this sort of tension
between humility on the one hand and the sense that we
can have the audacity to live in the universe and
attempt to understand it was already articulated by Blaise Pascal, when he said, "The spaces
of the universe enfold and swallow me up like a speck;
but by the power of thought, I may comprehend the universe." But, Pascal flourished in
the 16th and 17th century, where science was still relatively modest in its accomplishments. So his was intuition and intuition, an that the universe
could be comprehended. And I think probably what
he meant by comprehended is just that you could look at it all, look out there and get an
idea that it was much bigger. Einstein, who in the 20th
century saw much more of the development of
science and of course, even he did not have access
to this Hubble Space Telescope or to our modern understanding
of fundamental physics. He was groping towards
unification and only knew about two of the four
forces we know about, and we've made enormous
progress since then. He struggled with quantum
mechanics and now we're learning to really apply it in
great detail and control it to put it to work, but in any
case, Einstein articulated the same thought that the
word, the most incomprehensible thing about the world is
that it is comprehensible. That was also... I mean, it's easy for someone to say that, but that also has an objective correlate. One measure of how well
we comprehend the world is how well we can act on it,
how effectively we can act on it and if you look at
the chart of human wealth, how much we're able to
create in terms use of that, but take the universe as
it is and make it useful to our own purposes, this
is somewhat of an art to estimate exactly what that means, but economists have tried to
formulate a good definition of what world GDP per capita means and trace it historically
and you can argue about factors of two here,
but the overall trend that human productivity
was pretty much flat over most of history and extending and very, very slowly increasing at best, until with the rise of scientific
methods and technology, it's taken off exponentially
and there's no end in sight. So we really do comprehend things, it's not just that we've come to peace with our lack of
comprehension, but we've proved our comprehension by being
able to act effectively. So those are the two big lessons. Another big lesson that I've learned, is that answers breed questions. I'll give you just two examples of that so our comprehension is impressive, I hope I've conveyed, but it's incomplete. One way it's incomplete
is that astronomers have learned that there's
a component of the universe that we don't understand
that actually by mass, outweighs the part we do understand by about a factor of five, this is the so called dark matter. The methods that are used to uncover that there is dark matter are
advanced methods of astronomy and things like seeing how light is bent by the distributions of matter and seeing that there has to be
more matter than we know how to account for and we have ideas about what that might be. We have very attractive
theoretical proposals, something I called axions
is a leading proposal, and since we have equations
for how axions are supposed to behave, we can design
antennas that are capable of detecting it, of
turning it into signals that we can see, and
this is a representation of how better understanding
of the universe has led us to new questions and new
methods of addressing those questions that will
bring more of the universe into our conscious awareness and control. Another frontier of questions
that we're beginning to approach is understanding
the basis of mind and matter. So we now have, I think
it's hard to question, although one can question,
but it's hard to question successfully, I would
say, an understanding of the kind of matter that
supports biology and chemistry and geology and all forms of engineering and almost all sorts of
astrophysics and cosmology that's detailed and
complete and well-tested and it gets down to more
accuracy and accuracy to spare and tested despair for
all those applications. So we have the fundamental basis to see whether like the phenomena
of metabolism and heredity, which have now been understood
on a molecular basis, whether mind can also be
understood on a molecular basis. So our knowledge of how
this eye is based in matter is kind of beginning to pose questions that can be answered and closing the loop. Another thing that I
like about this picture that is due to John Wheeler
is that it also alludes to the fact that we
understand, in broad outlines, the history of the
universe that can give rise to this brain. So we're both understanding
where we came from at the level of history and understanding, where we came from and what we are at the level of fundamental
laws and matter. Another great lesson that
I've learned from reality is kind of a medal lesson that
is called complementarity. This is the idea that
different ways of viewing the same thing can be both
informative and both valid and yet difficult or impossible to maintain at the same time too and so this is a kind of
theorem in quantum mechanics. You cannot understand quantum mechanics without complementarity
because the ways of answering different kinds of
questions, for instance, questions about position versus questions about velocity, require processing
the fundamental reality, in this case, the wave
function in incompatible ways. That's the origin of Heisenberg's
uncertainty principle and the formalism of quantum mechanics and the origin of Bohr's
principle of complementarity, which he took in quantum
mechanics, out into the world of philosophy and world
understanding in general. To me, a beautiful
example of complementarity that kind of brings it down to earth and actually corresponds in
the mathematical formalism very closely to this
complementarity of quantum mechanics that I mentioned is, in a piece
of music, you can analyze it either in terms of the
harmonies it contains, or the melodies it contains, but you can't really do both at once. If you're gonna do the
harmonies, you have to pay well, equal attention to
all the voices at once, if you're going to look at the melodies, you have to disentangle
the voices and look at it sort of horizontally
integrating over time, as opposed to taking slices in time. Another memorable example
of complementarity that I really like, it's
simple-minded and funny but really profound in a way, is, is this object a rabbit or a duck? Well, it's both (laughs)
but only one at a time, and that's an example of,
to understand it completely, you have to take different points of view and each one is informative
and yet each one excludes the other, and only by expanding your mind and allowing yourself to
analyze and think about things in different ways do you do full justice to the underlying reality of things. And to me, this spirit of complementarity leads to a different way of
understanding the tension between free will and
determinism, for instance, that does not lead to just
a pointless discussions that go around and around
in circles, but accepts both as answers to different
kinds of questions. It's a liberating mind expanding
attitude towards the world that you can take from
fundamental understanding of the world out into
experience and life and wisdom. So that's a small sampling of
what reality has taught me. There's lots more and I
wanted to open this occasion to discussion, and I hope there'll be questions and challenges
and explorations to follow, but just let me tell you
that there's lots more in this book that just is
being released today in the US, well, on Amazon, so you can
get it, and it expands greatly on those and other fundamental lessons that I've learned from reality. And, let me just quickly go through without detailed discussion,
but so that you can ask about them more and also get a sense of what is taken up in the book. There are 10 assertions, which
are these 10 keys to reality, and they are, there's plenty of space, both external and internal,
we talked about that, and similarly, there's plenty of time, both external and internal. I analyze the speed of
thought and then quantify how many thoughts you
can have in a lifetime, and there are billions,
so there's plenty of time, even though we live a short
time compared to the universe. There are very few ingredients. We learned that the world is
made out of just a few things that have very special
understandable properties. There are very few laws that
tell us how they behave, and there's plenty of matter and energy. The universe is large, not
only in space and time, but also in terms of the
resources that we can tap into. So if we don't blow it, humanity can have a very bright future. So that kind of is about the fundamentals of what there is, and then in
the second part of the book, I discuss, sort of how
they act in the world, how they have acted and some
ideas about how they will act and how one should
understand it going forwards, so, one big lesson is that
cosmic history is an open book. We really can penetrate back
to the very, very early history of the universe with
observations and evidence and piece together a broad
history of what happened and how we got here, but we also learn that that does not account for everything, the simple laws and simple
beginnings don't tell us about the details of what emerges, but there are fundamental limits
to how much you can extract from fundamental understanding, things like quantum mechanical,
uncertainty and chaos intervene and we can understand
how complexity emerges, so that for instance,
the history of England can be much more complicated than the history of the universe. We understand that there's
plenty more to see, the fundamental understanding teaches us that our centers reveal only a small part of what's out there, but
they also reveal ways we can try to improve
on our understanding, on our access to reality, and
we can do that in small things like timekeeping, the
watches that we carry around, but also in advanced
projects that open us up to seeing things like gravitational waves or Higgs particles and
hopefully, the dark matter. Mysteries remain and
complementarity is mind-expanding. So I hope I gave you a
sense of what I've learned from reality and what I've
tried to share in fundamentals. So with that, I'll open
things up for questions. - Wow, thanks very much, Frank. Normally, regular viewers
will know that we play out a bigger video of applause
happening, but unfortunately, due to the new platform that
that hasn't happened just yet. But thank you so much for that talk. We've had quite a few people in the chat asking various questions. I just wanna say something before I launch into the questions. I do want to apologize
'cause we had a little bit of a bumpy start to the stream. I forgot to read out some other things I was gonna let people know about you. So, what I was gonna do, before I kinda panicked
and just threw to Frank straight away, 'cause, I
was like slightly nervous, was I was gonna read you
the top three comments on Frank's previous, YouTube video, 'cause I think they'll give you... You can look up his academic CV, anyway. You can look at the many,
many prizes and professorships he has, but I thought you might enjoy what the general public, the
people out there say about him. So, comment one, "This guy
gives amazing lectures, is calm, precise, voice is hypnotic." The second one says,
"Wilczek is brilliant, his book, "The Lightness
of Being" is a great start for anyone who wants to
stand the strong force by quantum chromodynamics." And finally, "Seems
like a pretty cool guy. I'd like to see him do a cooking show." (both laugh) So there's the full range
of opinions on that. - That last one, I was anticipating. Yeah, that last one I was anticipating, 'cause we talked about it
before and that's what led me to think that, gosh, Faraday
could have given a heck of a cooking show and I'm sure
he would have really enjoyed talking about microwave
ovens since they come from his work on
electromagnetism pretty directly. - yeah. So sorry about that, for
the rather bumpy start. Let's go to some actual questions
about physics, shall we? So Mohammed, asks, "Is
there any reason to doubt the cosmological timeline? Is it definitive the way it stands?" I know other timelines that
we have, like the timeline of human evolution and few other things are kind of a bit contested
and we're not quite sure where did the (indistinct) fit? And we have sort of ideas, but
are we sort of pretty certain with the cosmic microwave measurements and other things that we can
go, "Yep, 13.7 billion, yep."? - It came down pretty firmly. I think all the events that I noticed, certainly, I didn't pour over
that timeline in great detail, I have to confess, but all
the events that I noticed were certainly well pinned down
by a variety of techniques, looking at redshifts of
different objects versus time, which tells us how big the
universe was at different stages and how fast the galaxies were receding. Looking at radioactive dating
which tells us about old rocks and also about events
of more recent history, looking at stellar revolution,
which you could look at stars with different colors,
doing different things in different places and
figure out how old they are. There are many, many lines
of evidence that form up this picture and you alluded to the microwave background
radiation, so that gives us sort of actual images
of the early universe from which you can infer a
lot of what was happening at the time the snapshot
was taken so to speak, but also what happened before with very plausible extrapolations
of the laws of physics, some of whose consequences we can check. Now, one thing that is
not certain though at all, to put it mildly, is the very
beginning of that timeline. What happens 13.8 billion
years ago is that the universe became very, very dense and
very, very hot, we think, but, what happens is not
that we know that it emerged from an explosion, but that we know our equations break down. We know the experimentally verified parts of our description of
the world that work up to a certain energy could have surprises, if we extrapolate the two higher energies and higher densities
than they've been tested. And in a way, we know that
something has to give, because if we take things back far enough and going backwards in time,
the universe gets smaller and smaller and hotter and
hotter and denser and denser, the equations just become
infinity equals infinity. They break down, they become
mathematically singular. So at some point... You shouldn't think of that
end point as an end point, what it means is that our
equation stopped working. It doesn't mean that the
universe stopped working or that it emerged from some
kind of truly singular event. The fact is we don't know
very well what happened, and we have some hope that by studying gravitational radiation,
which because it interacts so weakly with ordinary matter,
can sort of shine through to the earliest universe
in a way that others (indistinct) can't because
the photons get scattered and scrambled and so
forth, that we'll be able to look back further
but we're just getting the technology now to see those kinds of gravitational waves, precisely
because they do interact so weakly with matter, it's a
tremendous feat of technology to detect them at all, and we
have some theoretical ideas about what might've
happened on the so-called inflationary universe and
there's kind of circumstantial evidence that that understanding
can be extrapolated very far back, but ultimately,
we don't know what happened, We don't know the very beginning, so, there's certainly
room for surprise there, nor of course we know the
end (laughs) that hopefully, this year is not the only
year of cosmic history, and it's very interesting
to think what's gonna happen on the cosmological scales in the- - As you say that, Zenergy in the comments actually says that, "According
to the 24-hour clock analogy, we will flip over to a new
ion as Roger Penrose theory suggests, I think it's
the Cycles of Time theory, I don't know if you know about that. Would you like to comment on it? - It seems farfetched to me,
(laughs) but he's a smart guy. (Frank laughs) - I find that about Roger Penrose as well- - Anything I've been able to see, what. - That's why I was
hoping you'd help me out, 'cause it seems crazy, but
you're many, many times more intelligent than
I am, though (laughs). - Let me just say that
his picture is imaginative and kind of attractive on
broad philosophical grounds as a logical possibility, but
it is not a straightforward extrapolation of physical
law as we know it. On the contrary, it would require changes but at present there's no
real evidence for it, but... - While we're on this, the
structure of the universe, what was I gonna say? How would you explain the kind of the matter, anti-matter imbalance? Obviously, after the Big
Bang would be that we have more matter than anti-matter
cause I'm made of matter, but how can the looking at the history of the universe explain that? - Okay, well, first of all,
we have to establish the idea that there should be
balanced between matter and anti-matter to explain why. And I guess we have
intuition that the universe might've been ideally simple and maximally symmetric early
on, and that would suggest that there should be equal amounts of matter and anti-matter, but you can be more precise about it. If we extrapolate the Big Bang to very, very high temperatures and take the laws as we know
them, eventually, the reactions are such that if we run it
backwards, you would produce vast amounts of antiparticles together with particles in pairs, and
so you'd have an equilibrium, you'd have equal amounts
of matter and anti-matter, so it really is not just a nice
thing, but kind of mandatory to start with a balance
between matter and anti-matter at the very beginning or
as far as we can take it towards the beginning. And then you have to run
things forwards in time and to see how from that
condition of symmetry, an asymmetry developed. Now, the first thing to say
about that is that the asymmetry between matter and
anti-matter on cosmic scales is actually a very small effect. If you compare the number
of photons which were left, which are out in the microwave
background radiation, which is a measure of how
many sort of net particles they were early in the universe,
when the microwave photons first began to penetrate,
and be observable, so the universe became transparent to that kind of radiation as it is now, compare the number of
those kinds of photons to the number of quarks in the universe or the number of electrons,
you find that the number of photons is about a 10
billion times as much, so the matter as we call
it, represents an imbalance of about one part in 10 billion. If you started with
very, very large numbers of quarks and antiquarks comparable to the number of photons,
but almost all of them annihilated, and what's leftover is just one part in 10 billion. So, we have to explain a
very, very small imbalance that gives rise to the
universe as we see it today. Now, our control over
fundamental physical law is not really good enough
to quantitatively address that imbalance and how it arose, but we do have pretty good
ideas, how should I say it? It doesn't make a crisis
in fundamental physics 'cause we have pretty good
semi-quantitative ideas about interactions that have
a little bit of imbalance between how they want to produce
matter versus anti-matter, and ideas about how those
reactions would have played out, I mean, calculations
about how those reactions would have played out in the
evolution of the universe, and you can get the right answer, (laughs) but the inputs are so uncertain
that it's not so impressive that you can get the right
answer in several different ways, at most one of which is correct
(indistinct) (laughs) that. So, it's not a crisis, but
it's kind of a somewhat unsatisfying situation that
we have a rough understanding of how that asymmetry could
arise and within the framework of the fundamental laws as we know them, but not a precise understanding,
and unfortunately, not much prospect of getting
a precise understanding, because most of us believe
that the processes involved are revealed clearly only at
much, much higher energies and involve much, much heavier particles than we can actually produce
at accelerators in practice. - So actually, David asked
a follow up question, where he was basically
saying, is it supposed to kind of uniformly distributed,
this in a tiny imbalance, or is it kind of localized? Are there clumps of anti-matter out there? And is it kind of... 'Cause the universe is fairly
clumpy generally, isn't it? As a structure. - It's very clumpy generally,
but, there's no evidence for significant parts of the
universe that are composed of anti-matter and there are very strong arguments against it, those regions of the
universe, if they existed. But, first of all, the
most obvious evidence is not evidence, (laughs)
and you might say, "Couldn't, we just see
that it was anti-matter?" And you can't because
what we see is photons for the most part and photons
are their own antiparticles. So the photons produced by
anti-matter would be (mumbles) very nearly exactly the same photons that you would see from matter. So just by looking, you can't tell. However, if you have some
regions where there's matter and some regions where
there's anti-matter, where they collide, so to
speak, that the border regions would be very hot and emitting a lot of high energy
radiation, because the matter and anti-matter would
be annihilating there. So there's no evidence for that. There's also, if you
don't look at photons, but look at the cosmic rays,
which involve typically, protons and electrons
and matter, there's only a very small amount of
anti-matter in the cosmic rays and we can account for that in terms of secondary production of anti-matter. So there don't seem to be
any, it's very hard to think that there are parts of
the universe that are made out of anti-matter. It's really not possible to accommodate within astrophysics as we know it. And we believe and have
tremendous evidence for the idea that the universe early on
was much more homogeneous than it is today. The microwave background
radiation, for instance, which gives a snapshot of
the universe when it was about 100,000 years old, so 100,000 years after the Big Bang, is
uniform to within a part in 10,000, roughly. So there were no galaxies,
no clumps, no black holes, just kind of a uniform hay- - So that was gravity, basically, pulling everything together- - And then gravity magnified
very small density contrasts, so I like to say the rich get richer and the poor get poorer, so the parts that had over-densities of
matter have more gravity and pulling more and get even more dense, and the left behind places
don't get thinned out, and so that's, in very
broad terms, how galaxies and then planets and
some things get formed. - So, I've got a few more questions here. I've got quite a few
more physics questions, but I'm gonna give you
a break from physics, 'cause if you are gonna publish a book with such a wide outlook,
you've got to expect questions on lots of other subjects
as well, I'm afraid. - Oh, I mean, to me, well, physics has a hard core, of course, but physics really is about the world and my big aspiration in this
book and my big aspiration, really, in life is to understand reality and physics is a tool for that. Yeah. - And I absolutely think
that's why your work, the idea of complementarity comes in. I can look at this
painting on my wall and go, "Well, that's got this pigment
and this kind of canvas." and analyze it chemically, or
I can analyze it artistically. - Yes.
(indistinct) - But I'm just looking at the same thing. - Auto-correct, right and- - It tells me the- - Keith famously bemoaned that scientists had taken the magic out of a rainbow, but I think that's totally wrong. When I see it rain, it just
looks just as beautiful as it ever did. - Yeah. - And in fact, more beautiful
because now I understand how it arises and I can
make my own rainbows with prisms or a glass or water droplets, and understand why it is, and
it enriches understanding, and similarly, I feel, by
understanding electronics, I have a different
relationship to my computer than otherwise, and so on, and it enriches your
experience of the world to know how things work. - So, what now? When you mentioned GDP
earlier, we had a few people in the chat talking about GDP. And is it really a good measure
of wellbeing or is it... What is it actually measuring? And, I think you used it specifically to measure productivity, you
actually said productivity rather than- - Well, it's called... This is kind of... I'd have to confess I don't know exactly what goes into that measure of GDP. It's a construct of economics
and that's why I say I wouldn't be surprised if
different experts came up with different estimates that differed by a factor of two or something, but broadly speaking, another
measure that's more objective and I think gives more
or less the same answer is how much energy per
human is being used, how much energy is being
generated and used, in industrial processes
and just everything, how much energy does humanity control and put to its own use? And there's a baseline which
is based on agriculture, we use the energy to fuel our
bodies, and for a long time, that was the main economic
activity and so the GDP was flat, at just enough to keep us going, to keep the lights on in our
brains, which is about 30 Watts and heat our bodies and metabolism, which is about five times more. And there wasn't much of a surplus, but now we control energy to make things, for industrial processes
and you can quantify how much energy and it's
about, if I remember correctly, I discuss this quantitatively in the book, but, I think in advanced
countries, it's something like 100 times the
baseline and for humanity as a whole, it's something
like 50 times the baseline. So, that's an objective
measure of (laughs)- - So, another person, I
forget the name actually, but it was a really
interesting thing to bring up, mentioned a title of an article from 1960 called "The Unreasonable
Effectiveness of Mathematics in the Natural Scientists." - Oh, yeah. Barged by Eugene Wigner, which seems to be a similar kind of path that
you're trading here at the side. And so for those that don't know him, may just read up about it. He basically observed that... His theory was the mathematical structure of a physical theory, often points the way to further advances in that theory and even to empirical prediction. So by kind of putting something
into a mathematical form, you can then learn something
from those sorts of equations. I just wondered if you
have thoughts on that idea. - Well, it's really the theme
of my previous book (laughs), (indistinct) beauty in a
broad sense, has led us to a deeper understanding
of the physical world. The theme of this book is
kind of broadly speaking the other direction,
how understanding truth, leads us to beauty or at
least enriched understanding of the world and more wisdom
as well as seeing things in a richer way. In any case, yes, I mean,
especially over the course of the 20th century, when we
were struggling to understand very small things, atoms
and then atomic nuclei, where the experiments were difficult, and also to understand
the universe as a whole, where organic experiments
are very difficult, we've had to not follow
so much the Baconian ideal of gathering a lot of data
and just correlating facts. If we want to make progress
in fundamental understanding, what's really worked is to make guesses about how the world
might work and then see if those guesses are supported by facts, but to interpret the facts,
you have to have guesses that allow you to look
for the right things, which are often quite subtle and require a lot of image processing, so to speak, as we look at the very small
things or very large things, and it's been absolutely
extraordinary that the guesses that were based on kind
of aesthetic feelings about how the world
might work or should work to make the laws more symmetric, to make them more logically
perfect, more unified, have turned out to be correct, and that the world
actually works that way. Yeah, so. - So, another-
- Yes. - Sorry, I was just gonna
move on to another subject. So, one thing, again, sort
of just a gigantic subject, which we could do 50
lectures on, is the idea of consciousness and the
relationship with mind and matter. So obviously, I'm not
gonna ask you to explain all that just in like five
minutes, but I am gonna ask, Monte was asking, where
did you kind of read up on these things,
particularly the relationship between kind of mind and matter and the kind of molecular
level of proteins, whatever's going on in our
brain at the same time? - Well, I've read quite a
few texts on neurobiology, it's been an interest
of mine for many years. In fact, when I was an undergraduate, I flirted with going into that subject, but I liked mathematics and at the time it wasn't really ready for
mathematical treatment. Now with the study of
neural-net, it's getting there and also quantitative
biology, which we have much better probes and much more powerful ways of analyzing the data. But in any case, I followed
that for many years. If you're asking what's a good
introduction to these issues, I would defer to Francis
Crick the great biologist, and who in the last part of his career was struggling with these
questions of mind and matter. He wrote a book called "The
Astonishing Hypothesis", which kind of frames the question broadly, and the astonishing hypothesis,
which he advocates for is basically, the hypothesis
that mind emerges from matter. And why should we believe that? Well, there are many reasons,
but let me mention two that weigh heavily in
my thinking about it, one is that so far, people who studied... Well, this one is actually two, that people who've studied the brain and studied psychology have always found that the brain is the basis
of it, and when you injure the brain, you've change
the psychology and so forth. And neurobiology has really proceeded by assuming this astonishing hypothesis, and so far hasn't run
into any showstoppers. So it might someday, but
so far, I don't think so, I don't know. And, another aspect of that,
which is kind of complimentary, if you like, is that
in physics, we often do very delicate experiments
that require taking care of all kinds of possible effects that might distort the
results, so we have to worry about stray radio waves,
that we have to worry about tremors in the
earth, we have to worry about the temperature, we have to worry about all kinds of things,
but we've never had to worry about what the guy in the
lab next door is thinking. There's never been a
necessity to take into account effects of mind on matter. It would be a fantastic
discovery if one could find such a thing, and that would
be maybe the greatest discovery of all time in science,
and it's a challenge to people who think that there are souls that can control matter, and
so show me, what is the effect? Give me anything. So, okay. So, those are two things
and the other thing is that, in recent years, we've started
to make minds, I would say. My computer beats me at
chess and the programs like AlphaZero have
really taught themselves by playing against themselves, learned to be the world's
best chess and go players, and these kinds of games
were once thought to be among the highest intellectual
achievements of people and in those cases, and
now, with machine learning, we have machines that can interpret images and really also create artistic images and create, photographic images
that same seem very real. So they're doing very impressive
feats that in a human, we would certainly call
mind and creativity, and for sure those are based in matter because we designed them
based on the principles of quantum mechanics which allowed us to make the transistors,
which makes the circuits, and so we have, lots of
evidence that mind-like things can emerge from matter. We make them, and on
the other hand, we have, despite very delicate ways of inquiry, no evidence that there's something in mind that's separate from matter,
and so I think to me, it would be astonishing at this point, if Francis Crick's astonishing
hypothesis were not true, (Frank laughs) but that is not a closed
subject by any means, and there are certainly
things we don't understand and, I think one of the great
challenges to me personally, I feel, is, okay, so we
have these fundamental laws, which are stated in
terms of quantum fields and mathematical relationships. Where am I in those laws? I bet they seem to be describing
something very different from the world that I experience, and it's a very interesting challenge to find concretely how
minds and the things the way we experience the
world emerges, or not, from our fundamental understanding, 'cause as, as I said, I
think we understand matter well enough, the kind
of matter that brains are built out of, we
know we know what it is and how it behaves, we
think, well, enough, all our fundamentals are very
well tested and seem complete, and so, the question becomes well posed. This is an outstanding
example of great answers leading to great questions. Now, it's a concrete challenge and I, we have to show
how it works, right? And I think it's fair to
say that in broad outlines, we've understood how metabolism works, which was once thought to
be a kind of mysterious, special thing that life
does and we've understood how heredity works and how
that could empower evolution, but we don't understand really,
at the same level at all, how mind works and
that's a great frontier. - I've just got a quick plug here. So Ashman Singh in the
chat who I don't know, said Mark Psalms, the co-founder
of neuropsychoanalysis has just released his
book, "The Hidden Spring: The Source of Consciousness",
and just coincidentally, he will also be speaking
at the Royal Institution at the end of this month, so,
if you wanna find out more about "The Journey to the
Source of Consciousness", do join us on the 28th
of January for that one at 7:00 PM GMT. Thanks everyone. So, I'm just gonna be- - By the way, I mean, yeah, consciousness is a very interesting
subject that I do talk in a more specific way
also about in the book, and there are very interesting experiments that reveal some of the intuitions we have about consciousness,
are actually not well founded or I would say just wrong,
and a lot of what goes on in our brains is unconscious
and is reported to us and we think of it as we willed
something, but in reality, subconscious things have
happened and reported what their results to consciousness, to a special kind of attention
processing unit or modality that we think of as in control,
but in actual actuality is just an inch of report
for internal consumption about what our brains are
experiencing and doing. (the moderator laughs) - So, just before we let you go, I've got a few more physics
questions to round things off. So, Charles Perry asks, "What are the most likely
explanations of dark matter?" And, I guess, also asking
that kind of applying also dark energy as well. - Yeah, well, dark matter and dark... And I didn't enter into the
technicalities of dark matter versus dark energy, but
astronomers have found two rather different
phenomena that both affect, give gravity, so give cosmic forces that we would call gravity, that's not due to the kinds of matter that
we know, the kinds of matter that as I've mentioned,
we understand very well that participate in engineering
and biology and chemistry. One is called dark matter, the other one is called dark energy. Dark energy is really the
phenomenon that space has a mass, so space has a density which seems to be the same everywhere,
and this is a phenomenon that Einstein, in a way, anticipated because it's a logical possibility within the general theory of relativity, the so-called cosmological constant. So, we know how to fit it into
our description of the world, we'd like to understand it more deeply, but, well that's one thing
that we know how what it is, and unfortunately, I think our
prospects for drilling down into space and sorting out
everything that contributes to its density are very
difficult because space is very rich, seems to
have a lot of structure, all of which is
contributing to the density, some positive, some
negative, and to really see why there's this imbalance,
we'd have to have good control over all of it, and we don't. So that's an open question. A much more accessible question, it seems, is this dark matter, which looks like some kind of new particle
would do the job, it's a particle that has
to have certain properties, we have certain experimental constraints. It has to interact very
weakly with ordinary matter, of course, otherwise it wouldn't be dark. We would've seen signals
from it with the tools of astronomy, it has to be produced in the Big Bang, it has to be stable and physicists have come
up with various ideas for what it might be. My favorite is something called
the axion, which I am named and invented for other purposes. I didn't have dark matter in mind at all, it arose in attempts to
make the fundamental laws more beautiful and comprehensible. It actually has to do with the
understanding more completely the fact that the laws look
the same, run forwards in time and backwards in time and
that may seem very tenuously connected to the dark matter
problem, and it is, logically, but miraculously, it turned
out that by addressing one problem, you're led to
a very promising suggestion, you have to introduce
this new particle, axion, which turns out to have
exactly the right properties to be the dark matter. And so, thousands of physicists
around the world today are thinking about antennas,
or ways of observing this axion, which supposedly
it's the dark matter. So it's all around with
making more of the mass of the universe than ordinary
matter, but interacts very weakly with our experimental tools, but the equations are definite
enough that you can use them to test the theory and well,
it's hard work and people are just now acquiring
the technical muscles to really be able to do
it, and watch this space, in the next five to 10 years,
I will either rule it in or rule it out, I hope so. I, well, hope to rule it in,
we might also rule it out. (both laugh) - So, they can't take
the Nobel prize back, Frank, it's fine. (the moderator laughs) - No, no, I will, right. No, no, well, of course, it has to do with something completely different, but that's done, but we're still looking forward to doing more stuff. And, (indistinct), I can't help, but say, since that we're talking and
this is the Royal Institution and Faraday and Maxwell, and so many, that this was very much the situation with Maxwell's equations, which to me is a continuing inspiration. Maxwell tried to make the
equations of electricity and magnetism as he knew them at the time, that came out of the work
of Faraday, especially, into a mathematical system
that was logically consistent and coherent and
beautiful, and to do that, he found that he had to
introduce a new effect and in a sense, a new particle, a new kind of electromagnetic
disturbances that nowadays, we call radio and infrared and microwave and gamma rays, and X-rays. None of those were known
at the time, and yet, by making the equations more beautiful, those equations contained
all those phenomena, and people had to design
antennas that were capable of detecting them because they
don't appear to our senses, and so it was a very
parallel kind of development. People had to work from the equations to develop the technology to
detect the predicted effects. Heinrich Hertz, who really was
the first person to do that set the stage for radio
technology, said that, you can't escape the
feeling that these equations are wiser than we are,
wiser than their creators. They contain more than was put into them. Yeah. - And just for my own head,
the axion theoretical particle, that's a different thing to the graviton? Is that right? So the graviton is a different- - Completely different- - Force carrying particle. Yeah. - Completely different. - 'Cause somebody else,
Jerry Lynn was asking, "Do you think we'll ever
discover the graviton, and if so, how?" - Well, I mean, the graviton is a particle that emerges
if you apply quantum theory to gravity, so just as when
you apply quantum theory to electromagnetism, you find
that the electromagnetic field actually exists in units called photons, that the electromagnetic
radiation can be thought of as made out of particles called photons. The quantum theory applied
to gravity tells you that gravitational
radiation should be made out of individual
particles called gravitons. Now, the existing on
gravitational radiation, sensitive as they are, really
are monitoring the effects of many, many gravitons acting together. (indistinct) So you can't detect whether
there's one more or less based on the response of the LIGO detector or any existing experiments,
but there's hope, I think, and that's one thing I'm
working on these days, is that there may be effects
that are more complex that than have been
taken into account so far in the theory of gravitational radiation, where quantum mechanics really
plays an important role. I think these could
arise in the last moments of black hole mergers,
which was one of the things that's studied at these detectors, and because quantum
mechanics becomes important theoretically in those
regimes, I'm thinking hard about ways that that might
be access to experimentally, but that's the future, at present we have good theoretical grounds because it's the logical
synthesis of quantum mechanics and gravity leads us to predict
these systems of gravitons, but so far there's no direct
evidence for the effects of individual gravitons - Fantastic. So I think we'll start
to bring this to a close, but I'd be remiss if I didn't
give a shout out to everyone who's been chatting away in the live chat, and so I thank you very much
for all of your comments, I'm really sorry, we haven't
able to get through everything. There's been a few,
I'll be honest with you, I'm not a professional
physicist, but there's been a few people in the chat that
have maybe been suggesting alternative theories or their
alternative view of physics, which is far a bit from me to disagree with your view of physics,
Frank, but some people have taken it upon themselves to come up with their own interpretations. Somebody whose calling
themselves The Time Lord, says that the relativity
in quantum mechanics seem incompatible because
of the false belief that time slows down near massive objects. It doesn't, the measurements
of time is slowed down. Now, I just wonder if you'd
like to comment on that and how would we know if
it was the measurement or the thing itself, is that (indistinct) without measuring it? - I'm not sure exactly what that means. (both laugh) - But time does slow down
near massive objects. - If all measures of time
indicate that it's slowed down, I think it's a matter of
language more than anything, to say the time itself has slowed down. If there's some independent
meaning to time slowing down, that has to show up in
some kind of measurement and, okay, I mean, it's a
very interesting hypothesis that there are ways of distinguishing what's happened to time
around massive bodies than the ways we presently
know which, well, to a first approximation,
can all be described as saying that time slows down. There may be other benefit stations, but I don't know of anything
in our present understanding of fundamental laws that suggests that. And I might mention that
there's a lot of evidence for time slowing down and that effect being correctly described
by general relativity and even it's intersected
with quantum mechanics. These are things like the
Pound-Rebka experiment, also when computing
distances in the GPS system, you have to take into
account that time slows down near the surface of the earth and to get really accurate
results, you have to do that, and if it were wrong, GPS
would fail in significant ways. So there's a lot and there's
also evidence from stars when you have emissions of light
from a nearby heavy object, the spectral lines are shifted. So it's not a theoretical fancy that there's this time dilation
that's usually described by the idea that time slows down. As I said, there might be other effects, but I don't know what they would be without more specific suggestions, and so, most of us most practicing physicists, as far as I know, all of them, would say that time slows down. (Frank laughs) - Fair enough. So I think that's pretty much it. I've just got a few more things to go over before we finish the stream. Just a reminder to everyone out there, the Royal Institution
is open for you to join. If you like what we do, and
you want to support our work, please do consider becoming a member. all information's on
our website, rigb.org. There's also a suggested donation of £10. Again, if you've enjoyed the stream, want to hear more from us
and want to keep us going for another 222 years
then that would be much, much appreciated in
these very trying times. A lot of our money you
might, you might know, comes from hiring out our
building, running events, selling tickets, all that kind of stuff that we can't do at the moment. We don't get any money at
all from the UK Government, we're completely independent,
but that means we're obviously in a bit of a sticky
situation without the ability to generate as much revenue as we used to. So, if you can spare the money, really, really appreciate,
it will be really appreciated by everyone at the Royal Institution. Don't forget the talk from
Vicky Pope on Thursday, all about climate modeling. Frank, obviously your
book's launched today, but would you like to
remind people of some of your other fantastic books that you've written previously,
some of which you can see talks about on the Royal
Institution YouTube channel? - Well, my most recent book until this one was called "A Beautiful
Question", and as I said, it's about broadly speaking
beauty as, first of all, what it is in terms of a human history and how it's been realized
in different cultures and some forms of beauty
have deep relationships to our understanding of the physical world and have been an impressive
guide to making progress and understanding the physical world. That's the theme of that one and it ranges over a lot of history
and a lot of culture. This most recent book, as I said, is kind of in the other
direction, starting from truth and spinning out its
implantation's, beautiful or not, but I would say on the whole beautiful. I also wrote a book called
"The Lightness of Being", which is a full explication,
as much as it can be done without actually going into
the mathematical details, but doing real serious
work with the concepts, annex that most of our
mass that you find out when you weigh yourself on
a scale, most of the mass of our bodies, 99% or
more is based on energy, based on interactions of quarks and gluons that we understand on the basis
of a very beautiful theory, and so we understand how
mass arises from energy kind of reversing Einstein's
idea that energy can arise from mass, or running
it the other direction. And so, it's not an
exotic phenomenon, it's us in this origin of mass and energy. And then I wrote, a long
time ago, with my wife, Betsy Devine, a book called
"Longing for the Harmonies" that's a wide ranging discussion
of physics and cosmology. That's also very good. (both laugh) (indistinct) dated in part now,
but, I would say it touches on many of the same
things as fundamentals, but in a philosophical way and
a little bit more technical, but also meant to be
accessible to the public. Then I've written a couple
of technical books also, but probably... Well, those I'll leave you
to explore on the internet. (both laugh) - Oh, that's absolutely fantastic. And I've just noticed you're
also on Twitter @FrankWilczeck? - Yes, yes, yes. - So, do head over to- - I'm not as active as
I once was, but, yeah, you'll find some good stuff there and not too much bad stuff. (both laugh) - Well, do you consider
giving them a follow and just remains to me to thank you all for your amazing questions
and for joining us tonight and a big thank you to
Frank for just an absolutely fascinating talk and discussion. Thank you so much, Frank. - Thank you. Thanks for the opportunity,
and it's always a joy and an honor to stand or,
well, I'm not standing with Faraday, that's
good, but (indistinct). Yes, that's right, to sort
of commune with that spirit. Yeah, thank you. - Well, thank you so much, Frank. Take care of you and good night.
