Kind: captions
Language: en
the following is a conversation with
Roger Penrose physicist mathematician
and philosopher at University of Oxford
he has made fundamental contributions in
many disciplines from the mathematical
physics of general relativity and
cosmology to the limitations of
computational view of consciousness in
his book the emperor's new mind roger
writes that quote children are not
afraid to pose basic questions that may
embarrass us as adults to ask in many
ways my goal with this podcast is to
embrace the inner child that is not
constrained by how one should behave
speak and think in the adult world
Roger is one of the most important minds
of our time so it was truly a pleasure
and an honor to talk with him
was recorded before the outbreak of the
pandemic for everyone feeling the
medical psychological and financial
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your way stay strong
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my conversation with Roger Penrose you
mentioned in conversation with Eric
Weinstein on the portal podcast that
2001 Space Odyssey is your favorite
movie
which aspect if he could mention of its
representation of artificial
intelligence science engineering
connected with you there also seems
there which is so amazing and how they
science was so well done I mean people
say oh no you interstellar is the this
amazing movie which is the most
scientific movie but I thought it's not
a patch on 2001
I mean 2001 they really went into all
sorts of details regarding you know
getting me freefall well done and
everything I thought it was extremely
well done so just the details or
memorizing and also things like scene
where at the beginning they have these
and said sort of human ancestors which
is sort of right sort of Eames eggs
becoming monolith
yes and well it's the one where he
throws the bone up into the air and then
it becomes this I mean there's just an
amazing sequence there what do you make
of the monolith does it have any
scientific or philosophical meaning to
you this kind of thing marks innovation
not really that comes from arthur c
clarke
I was a great fan of Ossie Clark so it's
just a nice plot device yeah well that
plot is excellent yes
yeah so how nine thousand decides to get
rid of the astronauts because he it
she believes that they will interfere
with the mission that's right no it's
this view I don't know whether I
disagree that question in a certain
sense he was telling you it's wrong see
the the machine seemed to think it was
superior to the human and so it was
entitled to get rid of the human beings
and run the show itself what do you
think how did the right thing do you
think how's flawed evil or if we think
about systems like how would we want how
to do the same thing in the future what
was the flaw there well you're basically
question touching on questions you see
it's just one supposed to believe that
how I was actually conscious I mean it
was played rather that way that's know
how and was a conscious being
because Hal showed some pain some
cognizant the hell appeared to be
cognizant of its of what it means to die
yes and therefore had an inkling of
cautious yeah I mean I'm not sure that
aspect of it was made completely clear
whether Hal was really are just a very
sophisticated computer which really
didn't actually have these feelings and
somehow but you're right it didn't like
the idea being turned off how does it
change things if how was it wasn't
conscious well it might say that it
would be wrong to turn it off if it was
actually conscious I mean these
questions arise if you think I mean AI
one of the ideas it's sort of a mixture
in a sense you say if it's trying to do
everything a human can do and if you
take the view that consciousness is
something which would come along when
the computer is sufficiently complicated
sufficiently whatever criteria you used
to characterize its consciousness in
terms of some can come
national criterion so how does
consciousness change our evaluation of
the decision the hell made it's not to
say that people have been confused about
this because if they say these machines
will become conscious but just simply
because it's the degree of computation
and when you get beyond that certain
degree of computation it will become
conscious then of course you have all
these problems I mean you might say well
one of the reasons you're doing AI is
because you understand the device at
some distant planet and you don't want
to send a human out there because then
you'd have to bring it back again and
that's cost you far more than just
sending it there and leaving it there
but if this device is actually a
conscious entity then you have to face
up to the fact that that's immoral
and so the mere fact that you're making
some AI device and getting that thinking
that removes your responsibility to it
would be incorrect and so this is a kind
of plot floor and that kind of viewpoint
I'm not sure how you know people who
take it very seriously I'm gonna have
this curious conversation with with I'm
going to forget names and I'm afraid
because this is what happens to me in
the wrong moment I've said I'd Douglas
have said this after and he's written
this book god I wish I liked I thought
it was a fantastic book but I didn't
agree with his conclusion from girdle's
theorem I think he got it wrong is he
well just tell you my story you see
because I'd never met him and then I
knew I was going to meet him at the
occasion IRS she's coming anyone to talk
to me and I said that's fine
and I thought in my mind well I'm going
to paint him into a corner you see use
his arguments to convince him that
certain numbers are conscious you know
some integers large enough integers are
actually conscious and this was going to
be my reductio ad absurdum so i started
having this argument and he simply
leptin to the corner he didn't even need
to be painted into it he took the view
that certain numbers were conscious I
thought that was a reductio ad absurdum
but he seemed to think it was perfectly
reasonable point of view with
out the absurdum there yes interesting
but the thing you mentioned about how is
the intuition that a lot of the people
at least in the artificial intelligence
world had and have I think they don't
make it explicit but that if you
increase the power of computation
naturally consciousness will emerge yes
I think that's what they think but
basically that's because they can't
think of anything else well that's right
and so it's a reasonable thing I mean
you think what the brain do what does do
a lot of computation I think most of
what you actually call computation is
done by the cerebellum I mean this is
one of the things that people don't much
mention and when I come to this subject
from the outside and certain things
strike me which you hardly ever hear
mentioned em you hear mentioned about
the left-right business they move your
right arm that's you're on the left side
of the brain and and so on and all that
sort of stuff and it's more than that if
you you have this plots of different
parts of the brain they're they're two
of these these things called the
homunculus which you see these pictures
of a distorted human figure and showing
different parts of the brain controlling
different parts of the body and it's not
simply things like okay the right hand
is controlled and since both sensory and
motor on the left side left hand on the
right side it's more than that vision is
at the back basically your feet at the
top I mean so it's about the worst
organization you can imagine right yeah
so it can't just be a mistake in nature
there's something going on there and
this is made more pronounced when you
think of the cerebellum the cerebellum
has when I was first thinking about
these things I was told it had half as
many neurons or something they're bad
comparable and now they tell me it's got
far more neurons in the cerebrum then
cerebrum is this sort of convoluted
thing at the top people always talk
about cerebellum is this thing just
looks a bit like a ball of wool to the
back underneath
it's got more neurons it's got more
connections computationally it's got
much more going on than this friend the
cerebrum but as far as we know although
it's slightly controversial the
cerebellum is entirely unconscious so
the actions you have a pianist who
complains incredible piece of music and
you think of any moves this little
finger until this was key to get a hit
at just the right moment does he or she
consciously will that movement no ok the
consciousness is coming in it's probably
to do with the feeling of the piece of
music that's being performed and that
sort of thing which is going on but the
details in what's going on are
controlled
I would think almost entirely by the
cerebellum that's where you have this
precision and they're they're really
detailed once you get I mean you think
of a tennis player or something does
that tennis player think exactly harder
which muscles should be moved in what
direction and so of course not but he or
she will maybe think well if the ball is
angled in such a way in that corner
there will be tricky for the opponent
and the details of that are all done
largely with the cerebellum that's where
all the precise motions but it's
unconscious so why is it interesting to
you that so much computation is done in
the cerebellum and yet is unconscious
because it doesn't it's it's the view
that somehow it's computation which is
producing the consciousness and it's
here you have an incredible amount of
computation going on and as far as we
know it's completely unconscious so why
what's the difference and I think it's
an important thing what's the difference
why is the cerebrum but all this very
peculiar stuff that very hard to see on
a computational perspectives like having
me everything have to cross over under
the other size and do something which
looks completely inefficient and you've
got funny things like the
frontal-lobe when the prett are where
did we call the Louvre and the place
where they come together you have the
different parts the control if you
wanted to do with motor and the other to
do with sensory and they're sort of
opposite each other rather than being
connected by a nuclear pie it's not just
though you've got electrical circuits
there's something else going on there so
it's it's just the idea that it's like a
complicated computer it just seems to me
to be completely missing the point there
must be a lot of computation going on
but the cerebellum seems to be much
better at doing that then the cerebrum
is so for sure I think what explains it
it's as like half hope and half we don't
know what's going on and therefore from
the computer science perspective you
hope that a Turing machine can be
perfectly can achieve general
intelligence well you have this
wonderful thing about during and girdle
and church and carry and various people
particularly Turing and I guess post was
the other one these people who develop
the idea of what a computation is and
there were different ideas of what a
computer developed differently I mean
church's way of doing it was very
different from Turing's but then they
were shown to be equivalent and so the
view emerged that what we mean by a
computation is a very clear concept and
one of the wonderful things that during
did was to show that you could have what
we call the universal Turing machine it
you just have to have a certain finite
device okay it has to have an unlimited
storage space which is accessible to it
but the actual computation if you like
is performed by this one universal
device and so the view comes away well
you have this universal Turing machine
and maybe the the brain is something
like that a universal Turing machine and
it's got maybe not an unlimited storage
with a huge storage accessible through
it and this model is one
which is what's used in ordinary
computation it's a very powerful model
and the universalness of computation
it's very useful you can have some
problem and you may not see immediately
how to put it onto a computer but if it
is something of that nature then there
were all sorts of sub programs and
subroutines when all the I mean I
learned a little bit of computing when I
was when I was a student but not very
much
it was enough to get the general ideas
and there's something really Pleasant
about a formal system like that yeah
well you can start discussing about
what's provable what's not these kinds
of things and you've got it you know a
notion which is an absolute notion this
notion of computability and you really
address when things what mathematical
problems are computed ly solvable and
what chance so and it's a very beautiful
area of mathematics and it's a very
powerful area of mathematics and it
underlies the whole sort of once I have
their principles of computing machines
that we have today could you say what is
Gaydos and completeness theorem and how
does it maybe also say is it
heartbreaking to you and how does it
interfere with this notion of
computation preciousness sure where the
ideas basically ideas which I formulated
in my first year as a graduate student
in Cambridge I did my undergraduate work
in mathematics in London and I had a
colleague Ian Percival we used to
discuss things like computational
logical systems quite a lot I'd heard
about girdles theorem a bit worried by
the idea that it seemed to say there
were things in mathematics that you
could never prove and so when I went to
Cambridge as a graduate student I went
to various courses you see I was doing
pure mathematics I was doing algebraic
geometry of a sort a little bit
different from my supervisor in people
but it was an area and I was interested
I got particularly interested in three
lecture courses that were nothing to do
with what I was supposed to be doing
when was the course by Hermann Bondi on
Einstein's general theory of relativity
which was a beautiful course he was a an
amazing lecturer brought these things
alive absolutely and now that was a
course on quantum mechanics given my
great physicist Paul Dirac very
beautiful course in a completely
different way it was he was very kind of
organized and never got excited about
anything seemingly but it was extremely
well-put-together and I found that
amazing too third course there was
nothing to do with what I should be
doing was a course on mathematical logic
I got I say my discussions were being
Percival was incompleteness theorem
already deeply within mathematical logic
space was were you introduced I was
introduced to it in detail by the course
but Burstein and he it was two things he
described which were very fundamental to
my understanding one was Turing machines
and the whole idea of computability and
all that so that was all very much part
of the course the other one was the girl
of theorem and it wasn't what I was
afraid it was to tell you there were
things in mathematics you couldn't prove
it was basically and he phrased it in a
way which often people didn't and if you
read Douglas Hofstadter's book he
doesn't you see but Steen made it very
clear and also not in a sort of public
lecture that he gave to a mathematical I
think it may be the atom Society one of
the mathematical undergraduate societies
and he made this point again very
clearly that if you've got a formal
system of proof so suppose what you mean
by proof is something which you could
check with a computer so to say whether
you've got it right or not you've got a
lot of steps have you carried this
computational procedure well following
the proof steps of the proof correctly
that can be checked by an algorithm by a
computer so that's the key thing now
what
have to now you see is this any good if
you've got an algorithmic system which
claims to say yes this is right this
you've proved it correctly this is true
if you've proved it if you made a
mistake it doesn't say it's true or
false but if you have if you've done it
right then the conclusion you've come to
is correct now you say why do you
believe it's correct because you've
looked at the rules and you said well
okay that one's all right yeah and that
one's all right what about that harm not
yeah I see I see why it's all right okay
you go through all the rules you say yes
following those rules if it says yes
it's true it is true they've got to make
sure that these rules are ones that you
trust is if you follow the rules and it
says it's a proof is the result actually
true right and that your belief that's
true depends upon looking at the rules
and understanding them now what girl
shows that if you have such a system
then you can construct a statement of
the very kind that it's supposed to look
at a mathematical statement and you can
see by the way it's constructed and what
it means that it's true but not provable
by the rules that you've been given and
it depends on your trust in the rules do
you believe that the rules only give you
truth if you believe the rules on you
give you truth then you believe this
other statement is also true I found
this absolutely mind-blowing when I saw
this it blew my mind oh my god you can
see that this statement is true it's as
good as any proof because it only
depends on your belief in the
reliability of the proof procedure
that's all it is and understanding that
the coding is done correctly and it
enables you to transcend that system so
whatever system you have as long as you
can understand what it's doing and why
you believe it only gives you truths
then you can see beyond that system now
how do you see beyond it what is it that
enables you to transcend that system
well it's your understanding
of what the system is actually saying
and what the statement and you've
constructed is actually staying just
this quality of understanding whatever
it is which is not governed by rules
it's not a computational procedure so
this idea of understanding is not going
to be within the rules of the sort of
within the formal system yes yes rules
anyway yeah because you have understood
them to be rules which only give you
truths they be no point in it otherwise
I'm a people say well ok this is what
this one said the rules as good as any
other well it's not true you see you
have to understand what the rules mean
and why does that understanding of the
mean give you something beyond the rules
themselves and that's that's what it was
that's what blew my mind it's somehow
standing why the rules give you truths
enables you to transcend the rules so
that's where I mean even at that time
that's already where the thought entered
your mind that the idea of understanding
or we can start calling it things like
intelligence or even consciousness is
outside the rules yes since I've always
concentrated on understanding you know
people say people somebody knows well we
know but about creativity that's
something a machine can't do is great
well I don't know what is creativity and
I don't know you know somebody can put
some funny things on a piece of paper
and say that's creative and you could
make a machine do that is it really
creative I don't know he said I worry
about that one I sort of agree with it
in a sense but it's so hard to do
anything with that statement but
understanding yes you can you can make
go see that understanding whatever it is
and it's very hard to put your finger on
it that's absolutely true can you try to
define or maybe dance around a
definition of understanding to some
degree but I don't often once it's about
this but there is something there which
is very slippery it's something like
standing back and it's got to be
something you see it's also got to be
something which was of value to our
remote ancestors because I sometimes
there's a cartoon which I drew sometimes
showing you how all these there's a in
the foreground you see this
mathematician
just doing some mathematical theorem
this little bit different job in that
theorem but let's not go into that he's
trying to prove some theorem and he's
about to be eaten by a saber-toothed
Tigers he's hiding in the in the
undergrowth you see and in the distance
you see his his cousins building growing
crops building shelters domesticating
animals and in this light foreground you
see they built a mammoth trap and this
poor old mammoth was falling into a pit
you see and all these people around him
are about to grab him you see and well
you see those are the ones who the
quality of understanding which goes with
all the it's not just a mathematician
doing some mathematics this
understanding quality is something else
which has been a tremendous advantage to
us not just to us see I don't think
consciousness is limited to humans
that's the interesting question at which
point if it is indeed connected to the
evolutionary process yeah
at which point is we pick up this very
hard question it's certainly I don't
think it's primates you know you see
these pictures of African hunting dogs
and how they they can plan amongst
themselves how to catch the antelopes
didn't some of these and David
Attenborough films I think this probably
was one of them and you can see they're
hunting dogs and they divide themselves
into two groups and they go in two
routes two different routes one of them
goes and they sort of hide next to the
river and the other group goes around
and they start yelping at these then
embark I guess whatever noise hunting
dogs do the antelopes and they sort of
round them up and they chase them in the
direction of the river and they're the
other ones just waiting for them just to
get because this when they get to the
river it slows them down and so they
pounce on them so they've obviously
planned this all out somehow I have no
idea how and there is some element of
conscious planning as far as I can see I
don't think it's just some kind of
there's so much of AI these days
they call bottom-up systems is it yeah
where you have neural networks and they
and they you give them a zillion
different things to look at and and then
they sort of you can choose one thing
over another this because it's seen so
many examples and picks up on the wrong
signals which your mom may not even be
conscious of and that doesn't feel like
understanding there's no understanding
and that whatsoever so well you're being
a little bit human centric so well what
exactly I'm not with the dogs Emma no
you're not sorry I'm not human centric
but I misspoke by a la biologie centric
is it possible that consciousness would
just look slightly different well I'm
not saying it's biological because we
don't know all right I think other
examples of the elephants is a wonderful
example to where they it's just I think
this was about that's number one
well they the elephants have to go from
along with the troop of them have to go
long distances and the leader of a troop
is a female they are apparently and this
female that she had to go all the way
from one part of the country to another
and at a certain point she made a detour
and they went off in this big detour all
the troop came with her and this is
where her sister had died and there were
her bones lying around and they go and
pick up the bones and they hand it round
and they caress the bones and then they
put them back and they will go back
again how am i doing that's so
interesting I mean there's something
going on there's no clear connection
with natural selection there's just some
deep feeling going on there we have to
do with their conscious experience and I
think it's something that your overall
is advantageous a natural selection but
not directly to do with natural
selection I like that there's something
going on and go on going on there yeah
like I told young Russian so I tend to
romanticize all things of this nature
that that it's not merely cold hard
computation perhaps I could just
slightly answer your question you were
asking me what is it
there's something about sort of standing
back and thinking about your own thought
processes I mean there is something like
that in the girdle thing because it's
just you're not following the rules
you're standing back and thinking about
the rules and so there is something that
you might say you think about you're
doing something that you think what the
hell am i doing and you sort of stand
back and think about what it is that's
making you think such a way just take a
step back outside this the game you've
been playing yeah you back up and you
think about yeah you're just not playing
the game anymore you're thinking about
what the hell you're doing in playing
this game and that's that's somehow it's
it's not very precise descriptive but
somehow feels very true that that's
somehow understandings yeah this kind of
reflection a reflection yes yeah there
is some it's a bit hard to put your
finger on but there is something there
which I think maybe could be unearthed
at some point and see this is really
what's going on why conscious beings
have this advantage what it is that
gives them an advantage and I think it
goes way back I don't think we're
talking about the hunting dogs and the
elephants that's pretty clear that
octopuses have the same sort of quality
and we call it consciousness yeah I
think so
seen enough examples of the way that
they behave and the evolution route is
completely different
does it go way back to some common
ancestor or did it come separately my
hope is it something simple but the hard
question if there's a hardware
prerequisite you know we have to develop
some kind of hardware mechanisms and our
computers like basically as you suggest
I'll get to in a second we kind of have
to throw away the computer as we know
today yeah the deterministic machines we
know today is it tried to create it
I mean why my hope of course is not but
well I should go really back to the
story which instance I'm finished
because I went to these three courses
you see when I was a graduate student
and so I started to think
I'm really I'm a pretty view what you
might call a materialist in the sense of
thinking that there's no kind of
mystical or something around which comes
in from who knows where you still that
yeah you still throw your life into me I
don't like the word materialist because
this is just we know what material is
and that's that is what is a bad word
because there's no mystical it's not
some mystical something which is not not
treatable my science it's so beautifully
put just a pause on that for a second
your materialist but you acknowledge
that we don't really know what the
materialist that's right I mean I like
to call myself a scientist that's the
first but it means that yes we see the
question goes on here so I began
thinking okay if consciousness or
understanding is something which is not
a computational process what can it be
and I knew enough from my undergraduate
work I knew about Newtonian mechanics
and I knew how basically you could put
it on a computer there is a fundamental
issue which is it important or not that
computation depends upon discrete things
so using discrete elements whereas the
physical laws depend on the continuum
now is this something to do with it is
it the fact that we use the continuum in
our physics and if we model our physical
system we use discrete systems like
ordinary computers I came to the view
that that's probably not it
I might have to retract on that someday
but the view was no you can get close
enough it's not altogether clear I have
to say but you can get close enough and
you know when to this course and I'm
Bondy on general relativity and I
thought well you can put that on a
computer because that was a long time
before people and I've sort of grown up
with this how people have done better
and better calculations and they could
work out black about black holes and
they can then work out how black holes
can interact with each other spar around
and what kind of gravitational waves can
add and there's still a very impressive
piece of computational work how you can
actually
work out the shapes of those signals and
now we have LIGO seeing these signals
and they say yeah there's this black
hole spiraling through each other this
is just a vindication of the power of
computation in describing einstein's
general as if it a so in that case we
can get close we would computation we
can get close to our understanding of
the physics you can get very very close
now is that close enough you see and
then I went to this course by Dirac they
see I think it was the very first
lecture that he gave and he was talking
about the superposition principle and he
said if you have a particle you usually
think of particle can be over here or
over there but in quantum mechanics it
can be over here and over there at the
same time and you have these states
which involve a superposition in some
sense of it different locations for that
particle and then he got out his piece
of chalk some people say broke it into
as a kind of illustration of how the
piece of chalk might be over here and
over there at the same time and he was
talking about this and I my mind
wandered I don't remember he what he
said well I can remember he's just moved
on to the next topic and something about
energy he'd mentioned which I had no
idea what had to do with anything
and so I'd been struck with this and
worried about it ever since it's
probably just as well I didn't hear his
explanation because it was probably one
of these things to calm me down and not
worry about it anymore it's in my case
I've worried it about it ever since so I
thought maybe that's the catch there is
something in quantum mechanics where are
these super positions become one or the
other and that's not part of quantum
mechanics there's something missing in
the theory the theory is incomplete it's
not just incomplete it's in a sentence
that's not quite right because if you
follow the equation the basic equation
of quantum mechanics that's the
Schrodinger equation you could put that
on a computer too there are lots of
difficulties about how many parameters
you have to put in so on it can be very
tricky but nevertheless it is a
computational process modulo this
question about the
continuum that's before but it's not
clear that makes any difference so our
theories of quantum mechanics maybe
missing the same element that the
universal Turing machine is missing
about consciousness yes yeah this is the
viewer held is that you need a theory
and that that what people call the
reduction of the state or the collapse
of the wavefunction which you have to
have otherwise quantum mechanics doesn't
relate to the world we see to make it
relate to the world we see you've got to
break the quantum you've got to break
the Schrodinger equation Schroeder
himself was absolutely by this idea he's
owned his own equation I mean that's why
he introduced this famous Schrodinger's
cats as a thought experiment he's really
saying look this is where my equation
leads you into it there's something
wrong something we haven't understood
which is basically fundamental and so I
was trying to put all these things
together and said well it's got to be
the non computability comes in there and
I also can't quite remember right when I
thought this but it's when gravity is
involved in quantum mechanics it's the
combination of those two and that's that
point when we you have good good reasons
to believe this this came much later but
I have good reason to believe that the
principles of general relativity and
those of quantum mechanics most
particularly it's the basic principle of
equivalence which goes back to Galileo
if you fall freely you eliminate the
gravitational field so you're imagine
Galileo drawing dropping his big rock
and his little rock from the Leaning
Tower whether he actually ever did that
or not pretty irrelevant and as the
rocks fall to the ground you'd have a
little insect sitting on one of them
looking at the other one and it seems to
think oh there's no gravity here of
course it hits ground and then realized
something's difference going on but when
it's in freefall the gravity has been
eliminated
Galileo understood that very beautifully
he gives these wonderful examples of
fireworks and you see the fireworks and
explode and you see the sphere of
sparkling fireworks this remains a
sphere as it
as though there were no gravity so he
understood that principle but he
couldn't make a theory out of it
Einstein came along used exactly the
same principle and that's the basis of
Einstein's general theory Elizabeth II
know there is a conflict this is
something I did much much later so this
wasn't those days that's much later you
can see there is a basic conflict
between the principle of superposition I
think that Dirac was talking about and
the principle of general Co very well
principle of equivalence gravitational
fields equivalent to an acceleration P
pause for a second what is the principle
of equivalence it's this Galileo
principle that we can eliminate at least
locally you have to be in a small
neighborhood because you see if you have
people dropping rocks all around the
world somewhere you can't get rid of it
all at once but in the local
neighborhood you can eliminate the
gravitational field by falling freely
with it and we now see this with
astronauts and they don't you know the
earth is right there you can see the
great globe of the earth right beneath
them but they don't care about it they
as far as they're concerned there's no
gravity they fall freely within the
gravitational field and that gets rid of
the gravitational field and that's the
principle of equivalence so what's the
was the contradiction what's the tension
with superposition uh well what so we
just a backtrack for a second just to
see if we can weave a thread through it
all yes so you wish she started to think
about consciousness as potentially
needing some of the same not mystical
but some of the same imagine see this is
a complicated story so you know people
think oh I'm drifting away from the
point of something but I think it is a
complicated story so what I'm trying to
say I mean I try to put it in a nutshell
it's not so easy I'm trying to say that
whatever consciousness is it's not a
computation yes it's not a physical
process which can be described by
computation but it nevertheless could be
so one of the interesting models the
you've proposed as the orchestrated
objective reduction yeah that's going
from there you say so I say I have no
idea so I wrote this book through my
scientific career I thought you know
when I'm retired I have enough time to
write a sort of a popular book which I
will explain my ideas and puzzles but I
like beautiful things about physics and
mathematics and this puzzle about
computability and consciousness and so
on
and in the process of writing this book
well I thought I'd do it when I was
retired I didn't actually I would didn't
wait that long because there was a radio
discussion between edward fredkin and
marvin minsky
and they were talking about what
computers could do and they were
entering and entering a big room they
imagined entering this big room with the
other end of the room two computers were
talking to each other and as you walk up
to the computers they will have
communicated to each other more ideas
concepts things than the entire human
race had ever commute
so I thought well know where you're
coming from but I just don't believe you
there's something missing that's it's
not that so I thought well I should
write my book and so I did it was
roughly the same time Stephen Hawking
this writing his brief history of time
and Hades at some point the book you're
talking about the emperor's new mind
that's right and both are and incredible
books the brief history of time and I'm
person you mind yes it was quite
interesting because he got he told me
he'd got some Carl Sagan I think to
write that forward good gosh what am I
gonna do I'm not gonna get anywhere
unless I get somebody so I know I know
Martin Gardner so I wonder if he'd do it
so he did and it is a very nice forward
so that so that's an incredible book and
some of the the same people you
mentioned Ed Franken which I guess of
expert systems Fame and Minsky of course
people know in the eye world but they
represent the artificial intelligence
that do hope and dream that
intelligences am i thinking well you
know I see where they're coming from and
they're like from exercise rectus oh
yeah you're right
but that's not my perspective so I
thought I had to say it and as I was
writing my book you see I thought well I
don't really know anything about
neurophysiology what am i doing writing
this book so I certainly reading up
about neurophysiology and I rate I'm
nothing I'm trying to find out well how
it is the nerve signals could possibly
preserve quantum coherence and all I
read is that the second electrical
signals which go along the nerves create
some effects through the brain there's
no chance you can isolate it so this is
hopeless so I come to the end of the
book
and I'm more or less give up and just
think of something which I didn't
believe in this maybe this is the way
around it but no and then you say I
thought well maybe this book well at
least stimulate young people to do
science or something and I got all these
letters from old people instead
he's the only people who could had time
to read my book so I mean except for
Stuart Hameroff except for Stuart
Hameroff you don't have a rough road to
me and he said I think you're missing
something you don't know about
microtubules do you didn't put it quite
like that but that was more or less it
and he said this is what you really need
to consider so I thought oh my god yes
that's a much more promising structure
so I mean fundamentally you were
searching for the source of a non
computable source of consciousness
within the human brain yeah in the
biology and so what are mark if I may
ask what are microtubules well you see I
I was ignorant in what address I never
came across them and in in in the books
I looked at that's I only read rather
superficially which is true but I didn't
know about microtubules Stuart I think
one of the things here was impressed him
about them is when you see pictures of
mitosis that's a cell dividing and you
see all the chromosomes and the
chromosomes get their gate or gate line
and then they get pulled apart and so
that as the cell divides the half the
chromosomes go you know how their web is
divided into the two pass
and they go to different ways and what
is it that's pulling them apart well
those are these little things called
microtubules and so he starts to get
interested in them and he formed the
view well he was his day job or night
job of where every call it is to put
people to sleep except he doesn't like
calling asleep because it's different
general anesthetics in a reversible way
so you want to make sure that they don't
experience the pain that would otherwise
be something that they feel and
consciousness is turned off for a while
and it can be turned back on again so
it's crucial that you can turn it off
and turn it on and what do you do when
you're doing that what do general
anesthetic gases do and see he formed
the view that it's the microtubules that
they affect and the details of why he
formed that view is not wasn't clear to
me but there but there's an interesting
story he keeps talking about but I've
found this very exciting because I
thought these structures these little
tubes which inhabit pretty well
ourselves it's not just neurons
apart from red blood cell red blood
cells they inhabit pretty well all the
other cells in the body but they're not
all the same kind you get different
kinds of microtubules and the ones that
excited me the most and this is may
still not be totally clear but they're
ones that excited me most were the ones
that the only ones that I knew but at
the time because they were there very
very symmetrical structures and I had
reason to believe that these very
symmetrical structures would be much
better at preserving a quantum state
quantum coherence preserving the thing
without you just need to cut preserve
certain degrees of freedom without them
leaking into the environment once they
leak into the environment your loss so
you ought to preserve these quantum
states at a level which the state
reduction process comes in and that's
where I think the non computability
comes in and it's the measure
process in quantum mechanics what's
going on so something about the the
measurement process what's going on
something about the structure on the
microtubules yes your intuition says
maybe there's something here maybe this
kind of structure allows for the the
mystery the there was a moment of chance
yes it just struck me that partly it was
the symmetry because there is a feature
of symmetry you can predict preserve
quantum coherence much better with
symmetrical structures there's a good
reason for that and that impressed me a
lot I didn't know the difference between
the a lattice and B lattice at that time
which could be important now that could
in medicine this year which isn't talked
about much but that's some in some sense
details we could take a step back just
to say these people are not familiar so
this this this was called the
orchestrated objective reduction idea or
orko R which is a biological philosophy
of mind the postulates that
consciousness originates at the quantum
level inside neuron so that has to do
with your search for where where is it
coming from so that's counter to the
notion that consciousness may arise from
the computation performed by the
synapses yes the key point here
sometimes people say it's because it's
quantum mechanical it's not just that
see it's it's it more outrageous than
that you see this is one reason I think
we're so far off from it because we
don't even know the physics right you
see it's not just quantum mechanics
people say oh you know quantum systems
and biological structures no well he's
starting to see that some basic
biological systems does depend on
quantum I mean look you the first place
all of chemistry is quantum mechanics
people got used to that so they don't
count that so you said let's not count
come on chemistry we sort of got the
hang of that I think but you have
quantum effects which are not just
chemical in photosynthesis and this is
one of the striking things in the last
several years that photosynthesis seems
to be a basically quantum process which
is not simply create chemical it's using
quantum mechanics in a very basic way so
you can start saying oh well with
photosynthesis is based on quantum
mechanics why not behave you have
neurons and things like that
maybe there's something which is a bit
like photosynthesis in that respect but
what I'm saying is even more outrageous
than that because those things are
talking about conventional quantum
mechanics now my argument says that
conventional quantum mechanics if you're
just following the Schrodinger equation
that's still competing well so you've
got to go beyond that so you've got to
go to where quantum mechanics goes wrong
in a certain sense you have to a little
bit careful about that because the way
people do quantum mechanics is a sort of
mixture of two different processes one
of them is the Schrodinger equation
which is a an equation my Schrodinger
wrote down and it tells you how the
system the state of a system evolves it
evolves according to this equation
completely deterministic but it involves
in two ridiculous situations and this
was much frightening it was very much
pointing out with his cat he said you
follow my equation that's Schrodinger's
equation and you could say that you have
two cat a cat which is dead and alive at
the same time that would be the
evolution of the Schrodinger equation
would lead to a state which is the cat
being dead and alive at the same time
and he's more or less saying this is an
absurdity people nod I say oh well
Schrodinger said you couldn't have a cat
with deadly it's not that you see he was
saying this is an absurdity there's
something missing and that the reduction
of the state or the collapse of the
wavefunction or whatever it is is
something which is has to be understood
it's not following the Schrodinger
equation it's not the way we
conventionally do quantum mechanics
there's something more than that and
it's easy to quote Authority here
because Einstein at least three of the
greatest physicists of 20th century who
were very fundamental in developing
quantum mechanics Einstein one of them
Schrodinger another Dirac another you
have to look carefully it directs
writing because he didn't tend to say
this out loud too much because he was
very cautious about what he said you
find the right place and you cease he
says quantum mechanics is a provisional
theory we need something which explains
the collapse of a wavefunction we need
to go beyond the theory we have now I
happen to be one of the kinds of people
there are many there is a whole group of
people they're all considered to be a
bit you know bit Mavericks who believe
that quantum mechanics needs to be
modified there's a small minority of
those people which were really a
minority who think that the way in which
it's modified has to be with gravity and
there is an even smaller minority of
those people who think it's a particular
way that I think it is you see so so
those are the quantum gravity folks for
what's well you see quantum gravity is
already not this because when you say
quantum gravity what you really mean is
quantum mechanics and Clyde -
gravitational Theory so you say let's
take this wonderful formalism of quantum
mechanics and make gravity fit into it
so that is what quantum gravity is meant
to be now I'm saying you've got to be
more even-handed that gravity affects
the structure of quantum mechanics -
it's not just you quantize gravity
you've got to gravity as quantum
mechanics and it's it's a two-way thing
but then when you even get started so
that you're saying and we have to figure
out totally new ideas indirectly no yes
it's you were stuck I don't have a
theory that's the trouble so this is a
big problem if you say okay well what so
there I don't know so we may be in the
very early days sort of it is in the
very early days and there but just
making this point yes you see Stuart
Hameroff
to be open Rose says that it's got to be
a reduction of the state and so so let's
use it
the trouble is Penrose doesn't say that
Penrose says well I think that no no we
have no experiments as yet which shows
that yes there are experiments which are
being thought through and which I'm
hoping will be performed there is an
experiment which is being developed by
dirt Romney Stowe who is I've known for
a long time who shares his time between
Leiden in the Netherlands and Santa
Barbara in the US and he's been working
on an experiment which could perhaps
demonstrate that quantum mechanics as we
now understand it if you don't bring in
the gravitational effects it has to be
modified and and then there's also
experiments that are underway that kind
of look at the microtubule side of
things to see if there's in the biology
you could see something like that could
you briefly mention it because that's a
really sort of one of the only
experimental attempts in the very early
days of even yeah about I think there's
there's a very serious area here which
is what Stuart Hameroff is doing and I
think it's very important one of the few
places that you can really get a bit of
a handle on what consciousness is is
what turns it off and when you're
thinking about general anesthetics it's
very specific these things turn
consciousn