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what hello and welcome I am Caitlyn saxs
a senior producer for Nova and today we
are going to be having a conversation
with David Kaiser and we're going to be
talking about the fundamentals of
physics and by that I mean the
fundamental physics group and that's
physics uh with an f f y s i KS we'll
explain that in a bit but these were a
group of physicists who held quite a
reputation as the hippies of physics uh
but who also help catalyze the
advancement of quantum physics so we're
going to get into that we're going to
delve deep into some trippy stuff like
the nature of quantum entanglement and
how these aspects of nature are being
used in technology today so David Kaiser
is a professor of the history of Science
and a professor of physics at MIT he's
the author of several award-winning
books on the history of modern physics
including how the hippies saved physics
science counterculture and the quantum
Revival uh the subject of which we will
be talking about today of course he's
also featured in a number of NOVA
documentaries including particles
Unknown about nutrino Einstein's
Quantum Einstein's Quantum riddle what
what is the universe made of and most
recently this year's decoding the cosmos
I have to say when I um started to look
up how many films David has been in I
just stopped there I figured that's
enough but every time we at Nova talk to
David our mind is blown that's why we
put him in so many of our films some of
which he has actually helped Inspire so
my goal for this conversation today is
to share that with you to try to blow
your mind um without the use of any
psychedelic drugs uh or whatnot so David
thanks for joining us today are you are
you up for this challenge are you ready
to blow some Minds well I'll do my best
and Kaitlyn thanks so much for inviting
me on it's always r a treat to be able
to talk with you and all the colleagues
at Nova so thank you thank you um so
first little housekeeping um this is a
live conversation so to the audience
watching live if you have uh questions
for David please just drop them in the
chat and we will try to get to them all
right so David first let's let's start
with the basics what what was this
fundamental physics group yeah well as
you say they they spelled physics with
an F that already gives you an
indication they were they were open to
having a pretty fun time they didn't
take themselves too seriously and that's
part of what drew me to them actually
when I was working on this project so
the fundamental physics group was an
informal group they weren't formally
organized in any way it was a rag tag
group actually you know not quite a
dozen people um and they all kind of
found each other in the San Francisco
Bay Area uh in the early and mid 1970s
they began having regular meetings uh
most of the time every Friday afternoon
for some big open-ended discussions
about basically how does the world work
what's the world made of things like
what's how do they best try to make
sense of things like quantum theory
which was is then as now can can keep us
up scratching our heads at night um and
so uh so they they were a group of
people almost all of whom had either
completed phds in physics or in the
process they were active grad students
at the time but they were finding a kind
of frustration with the typical way that
that young physicists were being trained
especially in the United States at that
time uh they had all entered the field
with these you know dreaming big big
thoughts about about quantum theory
about relativity about black holes about
the Big Bang about these really deep
deep kind of Juicy stories of of how the
world works and they each found in their
kind of formal training especially at
the PHD level that it seemed to them at
least kind of narrow it seemed to kind
of cut out some of these bigger what if
or how does it all work kinds of
questions that had helped Inspire them
you know when they were young kids
teenagers and so on on their own
combined with that they had the the the
remarkable bad fortune of trying to
enter physics at what turned out to be
one of the worst times to try to get a
job as a young physicist is through no
fault of their own the entire field
especially in the United States although
it turns out similar Trends in many
parts of the world at that time there
was a kind of um rapid cut in the demand
for young physicists not just in
university positions to become young
professors but also in industrial labs
in government Labs there was just a huge
huge fall in the demand and the supply
was was exploding so it was a really
tough time to make a kind of typical
career in physics and these folks
decided Well well they weren't finding
their main questions answered in their
kind of typical
curricula they some of them felt like
what do they have to lose because the
typical career path was shifting kind of
under their feet and so they kind of
bumbled along and found each other
through the kind of accidents of history
and they made a little kind of study
group a discussion group in um in
Berkeley California and one of the
topics they were most excited about was
quantum entanglement and then and then
you know topics that would spring out
from
there um so I want to get to Quantum
because that requires a pause to try to
wrap our heads around it and I will say
despite having made a film on it I still
haven't wrapped my head around it I
don't know if anybody has actually fully
wrapped their head around quantum
entanglement But first you also
explained in your book um you know in
the 1970s is there's a growing New Age
movement pulling in some aspects of
Eastern mysticism and they're also
seeing something um really appealing or
some alignment with with the principles
of quantum physics can you explain a
little bit like what what was it that
they were seeing in quantum physics yeah
I I should start by saying it's a great
question Kaitlyn so you know the group
was is about you know again maybe 8 to
12 kind of core members and they were
kind of accordi and week by week more
people come and go but there was a core
group and even among that group there
was a wide range of opinions the their
own opinions or ideas would change um
over time so so even though it's not a
huge group there was variety among them
and for some of them just as you say
they got very very interested really
enthusiastic about all kinds of um
spiritual and and intellectual
Traditions beyond the ones that they had
experienced through their kind of
typical training uh and for some of them
ideas from various strains of Eastern
kind of spiritual or mystical Traditions
really really excited them like um
Confucianism like uh Daoism or Buddhism
Confucianism they're not the same as
each other those Traditions uh and some
of these folks got excited about trying
to do a kind of compare and contrast so
they some of them really became um you
know they would read a lot of books that
go to go go to lectures in the Bay Area
at a time when interest in these topics
was growing especially in the San
Francisco area at that time so one of
the things that got some of these folks
excited like like FR of COA who's a
member of this group uh he was
originally actually from Austria but was
at that point doing a post-doctoral
fellowship uh in in
California in Santa Cruz not so far from
Berkeley uh and so froff was really
noticing in his EXP ations there were no
there ideas at least in some of these
Eastern traditions of a kind of
underlying wholeness a kind of uh hidden
connectedness among things that might
appear to be separated that was one
thing that really resonated with frof as
a young person because it seems to be
parallel at least with ideas that he
really was grappling with day by day in
areas of quantum theory that in Quantum
in tanglement but not only in that is
there a kind of um could could the you
know could the whole be more than the
some of its part parts we might say and
that was something that he was he was
exploring or getting exposed to in his
reading in his lectures and in his own
um increasing kind of meditations and so
on that's an example he went on to write
a bestselling book about that called the
da of physics that as far as I know is
still in print speaking of a blockbuster
International seller but it was really a
kind of pet project a passion project of
copras because he was trying to really
sit with these two different sets of
ideas that to him seemed maybe to have
things to offer to each other so that's
a quick example um that that
a kind of notion of subject and object
might not be the same as a kind of
typical or traditional uh Western View
is there a role for the Observer that
might have an impact in what even gets
counted as being observed or what we
attribute to being something as a part
of objective reality are we bringing
something to that controversial
questions to this day in the in the
topic of quantum physics but again in
the 70s was getting some of these folks
really interested about possible
connections or at least parallels with
things were just beginning to
explore so it sounds like the idea of
quantum entanglement which I want to get
into in just a moment but basically the
idea that things can communicate faster
than the speed of light and also this
idea of the role of the observer in a
system are things that um both the
physicists of and I don't know what
you'd call them philosophers of the day
were very uh interested in so let's get
into what those are exactly from a
physics
perspect physics perspective
the quantum entanglement start at the
beginning this this came about what in
the early
1900s yeah I really gets articulated in
the 1930s mid 1930s so long before the
hippie days that were otherwise that
we've been talking about and in fact
entanglement is in that era was most
closely associated with names that
really we do know that we think of as
kind of unhp is like Albert Einstein and
Arin Schrodinger uh they each had kind
of Bohemian streaks in their own day but
they certainly weren't 1970s California
hippies let's be clear about that and so
uh what they were doing they weren't the
OG hippies right right that's fair to
say I think they'd agree with that
statement too if we could ask um but
what they were doing they were you know
these were some of the most important
architects of quantum theory the H1
Nobel prizes uh for their work
contributing to quantum physics also
it's important to remember is that both
Einstein and even Aaron Schrodinger by
this point became pretty convinced
Skeptics or critics of quantum theory so
they helped build this amazing edifice
and then over the intervening decade
from the 1920s to the 1930s and indeed
Beyond Einstein and schinger each
started kind of nursing these really
significant questions and even kind of
doubts crit
criticisms and so each of them began
thinking about what we now call quantum
entanglement partly because they were
convinced this couldn't be real in the
world they were trying to sus out do
does quantum mechanics predict such
strange sounding things and if so isn't
that a problem for quantum theory right
so so they're helping to articulate
things we still read their papers with
great profit to this day exceptionally
clear from the 1930s but their goal was
not to say hey there's this cool feature
quantum theory isn't that great their
goal for each of them Einstein and
ringer both and they're kind of egging
each other on through letters of the
time was to say this sounds just too
strange to be real it sounds like spooky
ghost stories as opposed to real physics
nonetheless what they began to to
identify is that if one took the
equations of quantum theory really at
face value as it had been worked out
already in the 1920s and 30s
quantum theory seem to suggest that
under certain circumstances if there
were two little bits of matter two
particles two um to things we could
imagine performing measurements on or
interacting with in a laboratory if they
moved very far apart arbitrarily far
apart um that they would still retain a
kind of connectedness so they weren't
clear at the time was did it involve
actually communication the word that
you'd used um there's some kind of
connection in fact as Einstein iously
called it dismissively in a letter to a
friend it looked like a spooky action at
a distance for him that was not terms of
Praise that it would looked like it was
like ghost stories of weirdness so the
idea was the equation suggested that
there was a kind of again that that a
Quantum system was more had more to it
than just adding up everything you might
know about one piece and adding what you
might know separately about a second
piece that there were connectedness or
correlations or connected behaviors that
the equation suggested could be real uh
beyond what you would ever be able to to
kind of think about in a classical
physics or say in a Newtonian
system and for for Einstein as for
Schrodinger this spelled trouble not
excitement um nonetheless I wrote these
papers in the 1930s actually was
schinger himself who coined the term
entanglement in English he had just fled
his job in Berlin because of the rise of
the Nazis he was doing more and more
work in the English language Schrodinger
coined the term entanglement Einstein
had likewise fled uh Berlin um earlier
and had resettled in the United States
so the two of them were now exchanging
letters across the Atlantic Ocean and
really kind of as I say kind of coaxing
each other to articulate their
criticisms of quantum theory around
topics like entanglement so that's where
this topic kind of stays so a number of
of the earliest kind of proponents for
quantum theory like Neils bore and his
younger colleagues M Heisenberg WF gang
poy a lot of these uh folks were were
kind of not too impressed with
Einstein's critique um they some of them
wrote their own responses that frankly
are hard to follow today and some people
call the responses kind of muddled it
was kind of you know a debate that
seemed not to go anywhere and so
Einstein and bour remained lifelong
friends but they never convinced the
other of how to think about Quantum the
about topics like entanglement in
particular and basically they both died
having not convinced the other over
after discussions that had had unfolded
over decades nearly 30 years uh soon
after each of them actually had passed
away as it turns out a much younger
physicist and member of the next
generation named John Bell who's
originally from Northern
Ireland was kind of dissatisfied by the
state of play by the state of discussion
of these topics and so he read
Einstein's paper very very carefully the
so-called epr paper Einstein had written
this paper with two younger colleagues
um uh Boris Podolski and Nathan Rosen we
usually use their initials
E this is the paper saying that quantum
entanglement proves quantum Theory there
is a problem with Quant quantum theory
that that's exactly right so that's
right so the epr paper published in in
in Spring of 1935 that's Einstein
podowski Rosen identifies this strange
prediction quantum theory and says
that's like too bad for quantum theory
right and so so John Bell much later was
reading that paper with great great
interest he read and was really
dissatisfied with Neil's B's response
that also had been published in in the
1930s and so B returned to this with
let's say fresh eyes younger generation
not quite beholden to the same um sort
of all the same assumptions that had
animated the ear earlier folks and what
bell did was he realized there might be
a way to really test this this question
and not just argue late at night through
kind of C cigar smoke um among friends
which is how Bor and Einstein tended to
talk about it Pipe smoke or cigar smoke
and so John Bell says maybe we could
actually force a showdown maybe there's
an empirical contrast between a world
that behaves the way Einstein assumed it
would have to and a world that would
obey these strange looking equations of
quantum theory and so Bell divide what
we now call in his honor Bell tests he
said maybe there's a way to actually
subject Paris of particles that have
been prepared a certain way conduct a
series of measurements on each member of
the pair and and try to understand
whether their behavior really lines up
is correlated in this much stronger set
of correlations that quantum theory seem
to suggest so what he did is he
basically took the the core ideas that
Einstein and Podolski Rose and had put
forward in the 30s and tried to codify
them what bell did was kind of codify
them any theory of nature that obeyed
what Einstein and his colleagues
considered kind of um um you
non-negotiable they core principles that
must lead to different predictions for
real experimental outcomes Bell is the
one who really first showed this
compared to the Now by that point fairly
standard predictions from the equations
of quantum theory and if when design
these clever experiments and conduct
them very carefully maybe we could sus
that out so that's what Bel did he
published that article in late in um in
uh in the year of 1964 so almost 30
years after the epr paper and schinger
similar work from the 30s uh and then um
this amazing body of work which now we
teach all our students we consider one
of the most significant papers in the
history of modern physics John Bell's
article uh it went nowhere it was
completely ignored in its early days in
fact uh it was published in 1964 it
received zero citations in the worldwide
sent of literature the next year he
received one citation two years later
and that was by John Bell himself it was
a self- citation no one was picking this
up literally no one uh and then what
caught my eye was the first among the
first to begin to pay attention was this
group that you and I began talking about
just a few minutes ago the group that
had called themselves the fundamental
physics group uh in
Berkeley this I mean the fundamental
Mysteries of the universe why was nobody
paying attention to that for a a
generation or more
it's a good question and that's partly
what I tried to explore in in the book
that you mentioned a lot I think a lot
of it has to do with the changing way in
which uh physicists were training newer
physicists and the changing kind of
landscape in which young physicists
found themselves during the period
between the 1930s and the 1960s or
really 1970s a lot changed in the world
a lot changed in physics in between one
of the big ones of course being the
second world war these enormous um
weapons projects uh like the nuclear
weapons project headquartered at Los
Alamos the Manhattan Project in the US
uh and and these you know huge kind of
Applied Physics projects that that
really enveloped a generation or two now
what happened especially in the United
States not only there coming out of the
second world war was a pretty
significant
reorientation in what seemed to count as
worthwhile physics I should clarify most
physicists in the United States were not
working on weapons projects after the
war the weapons projects continue to
grow the supply of young physicists grew
faster so it's not that everyone was
working on bombs afterwards at all those
projects were going strong but it was a
minority of the population but there was
a a kind of ripple effect nonetheless
and that really caught my eye when I was
wearing my historian's cap if you look
at changing textbooks in quantum theory
look look at changing lecture notes look
at changing homework assignments and
these things you we have paper traces
this was long before the internet so
people had to write stuff down like z o
which was the best thing for historians
paper trail all over place you see this
transition in what sort of is is taken
to count as as really kind of worth
celebrating or worth focusing on in
training young scientists young
physicists in particular so it's not
that they all started focusing narrowly
on nuclear reactions or let alone weapon
stuff but there was a focus on a kind of
pragmatic approach that we the the
attitude became it was often kind of
caricatured by the saying shut up and
calculate which was attributed to F and
it's not clear if ever said it but it's
it rang true with an attitude that he
and many many of his generation would
try to instill in their own students
their job is not they argued to stay up
late at night through the cigar smoke
arguing about what it all means but
actually to say let's put these
equations to work let's find new
phenomena build new things and let's ask
different kinds of questions not bad
questions I want to be clear in many
ways this was a golden age for physics
United States more Nobel prizes than
ever before people were finding really
important things that we still take for
granted and teach our students today it
wasn't bad physics it was a different
set of
priorities
so is it safe to say that physicists of
that day were creating Technologies
advancing science that relied on these
fundamentals of quantum physics to be
true they just weren't asking why they
were true I think that's a good gloss I
think that's exactly right that's
consistent with you know the questions
they were asked for their homework
assignments the way the textbooks were
being kind of Rewritten in the Years
after the end of the second World War I
think it's exactly that there's another
part that really intrigued me that I
think at least accentuated those Trends
and that's that coming out of the second
world war physics enrollments were
growing like crazy they in fact physics
was the fastest growing field of study
in the American University system of all
the fields around every field of study
was growing it was a huge influx of new
students thanks in large measure to
things like the GI Bill lots of people
who' served in the second world war now
have the opportunity to go to college
and some of wouldn't have had that
opportunity um if they hadn't served and
if there hadn't been this GI Bill huge
rapid rapid exponential growth in the
American University system and again
plays out with different rhythms in
other parts of the world as well uh
certainly very similar growth in the
Soviet Union at the
time um and then kind of uneven in other
places anyway even as as as every
department is growing none grew at a
faster rate than physics partly because
of those of the drama of the wartime
projects after the end of the second
world war these once highly top secret
projects like radar and the man
Manhattan Project were kind of unveiled
selectively unveiled and young
physicists became you know um kind of
heroes or were treated at least as as
cultural celebrities in a way that's
sometimes hard me and my colleagues to
imagine today they were some of them
were treated as really just like
basically like movie stars um and so the
enrollment were booming like never
before so that we treat you like a movie
star David I appreciate that you're no
of a movie star
well uh yeah the word Nova there seems
to M to play a role there Caitlyn anyway
no disrespect to my friends in Nova it's
not quite the same red carpet anyway I
love it but the point is it was really
kind of cultural phenomenon in the 40s
really into the 50s where even when when
like Time Magazine would conduct polls
of like you know the most prestigious
profession nuclear physicist would be
ranked like among the top three we
were're not there these days right um so
it was really a cultural phenomenon as
an educational phenomenon um and so the
the kind of floodgates opened so if you
ask yourself what's it like to teach you
hundreds of students in a class on
quantum theory when before the war it
might have been dozens you know as a
teacher I would imagine asking different
kinds of questions it's hard to grade
300 essays until what it all means
multiple choice you go to multiple
choice or you do you know really good
there was a there was a a collection of
really Exquisite calculating skill again
I want to be clear it's not like good
bad it's shift in what gets prioritized
and that post-war generation many of
them got extremely good at calculating
and doing kind of quantitative
math-based problem sets and that's not a
bad thing that's incredibly important
for for physics but what got kind of
shunted what got lower priority and kind
of pushed to the side and sometimes
actively denigrated but just kind of
squeezed out pedagogically as well were
these much more open-ended kind of
philosophically flavored questions about
let's try to ask qualitative questions
about what what it means for the world
to behave that way so I think a lot lots
of pushes and pulls on that generation
coming out of the second World War uh
and Bell was really educated in that era
he was one of the
outliers in fact John Bell recalled
later in his life that he was actively
advised not to pursue these
philosophical sounding was it all mean
questions because it would hurt his
career and he went on to an extremely
prestigious career as a let's say a kind
of straightforward particle physicist he
used equations of quantum theory
brilliantly there effects named in his
honor in in kind of mainstream nuclear
produ PHS to this day but it was really
a kind of side interest that he learned
to kind of keep quiet
about even though today we now realize
this was just absolutely foundational
you know uh mindboggling
work um I really want to get to the
quantum entanglement explanation but
just building off that for a second as a
historian of
science
um you you've seen
how this sort of anatomy of Paradigm
shifts in in in thinking and and is this
how it always happens is always these
outliers
or if you have any any commentary on on
what it actually takes to make big
shifts well that that's really
interesting so I I think there I don't
know it always takes that I think we can
find examples so this wasn't unique
let's put it that way this was the only
time we found that kind of outlier but I
think what what I find most interesting
as an historian is that it's almost
never the work of one
loansome you know genius or outlier or
anything else but we we a lot of the
work that my historian colleagues and I
really have fun trying to do and it
involves kind of detective work is try
to understand what are the shifting
institutions in which that work was
being done or uh in contrast to which
the outlier you know was positioning
themselves you know in contrast so that
what what was the taken for granted path
and how was that reinforced for example
through teaching through pedagogy
through the pattern of support you know
Financial or otherwise for certain kinds
of questions and so the the the outliers
first of all are almost never working
alone and secondly they're they're in a
kind of they're situated um in in a kind
of social universe that also is not
static doesn't sit still and that's
Again part of what really grabbed me
about the the the the shifts we're
talking about now you know the the
second world war drove in the United
States an unbelievable infusion of cash
in the sciences and in higher education
like literally never before and it
didn't last forever and it began to
rever the fortunes reversed equally
quickly so to shockingly fast with these
exponential drops in things like support
uh you know roughly a quarter Century
later so it's it's these kind of amazing
play of ideas and curious personalities
and ideas that are you know kind of
delicious and strange and hard to get
our heads around those aren't bubbling
up in in a vacuum they're also kind of
taking place uh aside some really
sometimes quite dramatic shifts in how
we get the work done yeah I I really
appreciate that and it's something that
we at Nova I think over the last few
decades have Al start to appreciate
moving away from this sort of Lone
genius model for how uh science is
Advanced because for the most part it
it's actually not and you know a few
often a few people get the credit you
know the Nobel Prize goes to just you
know a couple names right um but it's
the way new ideas get created is through
inter interaction it is and and what and
what are the conditions to allow those
interactions that accentuate some that
might make put a strain and sometimes
beyond the immediate control even the
immediate recognition of the folks that
we otherwise I think you're right tended
to to focus on maybe a bit too narrowly
yeah let's pause on the history for a
second I want to come back to it but
let's do a dive into quantum
entanglement terrific great this
phenomenon is hard to understand yeah uh
but you probably more than most people
have experienced trying to explain it so
what's what's your I don't know what's
your three minute uh explanation yeah it
it's it is it's just it's wonderful um I
think and also it is still kind of
beguiling it's it's not straightforward
and yet as as as I think you're already
setting us up we have better evidence
now than ever before it's it really
seems to be how our world works and so
it's worth you know three minutes maybe
even four um to try to to try to get our
heads around it so the idea really is
that
um that we we often make a lot of good
progress enormous progress over
centuries and centuries in fact trying
to understand the properties of one say
object one hunk of matter and how that
hunk of matter might interact with
another hunk of matter but each carrying
their own properties with them and
property sounds very abstract uh that
means if we're talking about little
particles what is its value of it spin
along the X Direction let's say that's a
fundamental property of many types of
quantum objects kind of intrinsic AGN
momentum we can measure it extremely
accurately in Laboratories now it's not
a hard notion even for undergrads to be
able to interact with
so one way we try to describe things
like uh little bits of matter is with
their spin spin along a certain
direction in space is spinning up or
down with respect to say the the X
Direction and so we might think that we
have two particles we could just
attribute a spin to each particle
separately and then ask about you know
um the combination their effects and
that's exactly where things start to
break down that what what B tests and in
this area of entanglement seem to really
accentuate is that the value that we
measure of say the spin of one particle
over here is going to be bound up in
ways that people found and still find
very hard to to Really wrestle with what
we measure here seems to depend on what
happened over there and the over there
could be across a a crowded laboratory
space a couple you know feet or meters
apart in principle according to Quant
the it could be across the Galaxy and
that's where it starts hitting up very
hard with other things that we take for
granted like local causes yield only
local effects if I if I hit something
here something shouldn't change there
instantaneously it should take time for
some physical process of information or
force to move through space over time
it's that conjunction of ideas that
anagement really forces us to to to
question let me unpack that a little
further if I were to take prepare these
particles send them off in opposite
directions and then perform a
measurement over here on particle a I
say oh I see it spin is is spin up along
the X Direction just having perform that
measurement is now going to change the
the measurement outcome for what a
colleague is going to find arbitr far
away now what I can't do is use that um
to send information we can't communicate
within Tang although people very smart
people have tried for a long time to
find a way to do that what it does is it
changes the the statistics the
correlations between the measurements
that we measured and so if I only am
sitting at one box and I see a stream of
particles coming at me I measure the
spin spin up spin down spin up spin up
spin up spin down I look it seem seems
to be a completely random set of
basically plus ones and minus ones as
far as I can tell there's no information
conveyed When I Look only at one box
that I have access to what's really
remarkable is that when my colleague who
might have been on alphas and Tor takes
a jet back uh and we compare our
notes only when we see the complete set
of that experiment what questions did I
ask what measurements did I perform
round by round over here what
measurements did my colag can perform on
her particle over there time and time
and time and time again that when that
we see when we each ask certain
questions in common we got related
answers we went when we asked different
questions those answers also lined up in
a spooky way so the particles were
behaving as if they somehow shared joint
properties even though we only saw
random noise at one box at a time is a
random box at each random outcomes at
each box it means I can't send a message
to her saying oh you know go um you know
change your stock portfolio because the
correlations only come from seeing the
combination of measurements performed
and outcomes received nonetheless when
we perform that when we get all the log
books together we find that the
particles are behaving in a correlated
way that far exceeds whatever could have
happened by chance if each of them had
definite properties on their own if I
just try to say each particle had a
value spin before I chose to measure it
I literally get the wrong answer my
friend and I together get the wrong
answers and so by attributing sort of
fixed properties to a particle that are
that are revealed by my measurement by
just making that assumption even saying
I don't know what it is I just assume
there's a value that gets revealed I get
different answers for the combined
experiment when I bring all the log
books together then I then then what
quantum theory predicts that might still
not be as clarifying as we'd
like but yeah so I want to get back to
the history because essentially and I
see why hippie's New Age movement
Eastern missm could see something
appealing here right basically physics
seems to be telling us that there is
some sort of way that particles are
communicating instantaneously which has
a lot of parallels sorry sorry sorry k i
be careful with the word communicating
because one of the things that came out
actually of this group's work was
something we now call the no signaling
or no communication theorem so so it's
not it's not like put it the way it's we
can guard against the following we've
done this with real experiments now for
Generations um decades now if it were
communication then we might expect
communication to have to um involve say
sending a signal even one bit a zero or
one from this side to that side and as
far as we know communication has a speed
limit the speed of light given
relativity and so we're able to do these
experiments shutting experimenting far
enough apart from each other the two
boxes two detectors
there's not time for a single light beam
a single you know status update on on
Facebook to get from that device to that
device so so they're not communicating
and then lay on top of that we have no
useful information we only have one box
so we can't receive a signal from the
other side know is so so what is the
verb what are they yeah it's it's
dissatisfying um I I tend to use the
word correlated uh but because
correlation implies you need the whole
set to then find these patterns you need
both
right um as opposed to like I just got
you know a message in my in my in my ear
yeah or or behaving as one system almost
their behavior is correlated that's
exactly right so the behaviors what we
what we measure will show patterns but
we can only sus out those patterns
frustratingly and yet bizarrely when we
bring the two sets of of kind of log
books together um and so and that wasn't
clear I should say even clarifying that
was part of what the work of this group
that we began talking about really
really did uh one of the members of that
group uh who was
um an enthusiastic participant in their
discussions Philipe abart who is a staff
scientist at the Lawrence Berkeley
National Laboratory and would meet with
them often he actually was responding to
these really joyful very clever thought
experiments that members of the group
other members of the group were coming
up with exactly to try to send messages
they wanted to have a kind of fast and
light Telegram and Philly Bart published
one of the first ever demonstr that even
according to quantum theory that
shouldn't work that won't work because
you need to you know bring both boxes
both log books together so we know that
I can say that with a straight face like
oh well there's a no signaling theorem
because the work of groups like like
this fundamental physics group because
it was not straightforward actually John
Bell himself ended his classic 1964
paper worried that maybe this did leave
the door open to fast and light
communication because it was because it
was so you know difficult to sus out so
I don't mean to make it sound like it
was so straightforward over the work um
over in that case about a decade and
then the decades ever since then people
clarifying that it's not exactly
communication but there's something
certainly spooky or unexpected that
still
happens so we left the the story the
history at at um John Bell has sort of
um envisioned a hypothetical way that
this could be experimentally tested
where do the fundamental physics group
come in what what happens next that
actually changes the field right so one
of the people who discovered John Bell's
article which otherwise as head was
really being ignored largely ignored in
the literature was at the time a PhD
student named John clauser clauser was
at the time at Columbia University in
New York uh in the late 60s and early
70s and he basically found Bell's
article by accident he was in the
University library and he found a funnyl
looking Journal Bell published his
article not one of the mainstream
journals for all kinds of reasons we can
talk about and basically as a kind of
study break from his main dissertation
project young John clauser found this
weird looking journal on the shelf and
he kind of took it took it off the shelf
and in great Serendipity you know kind
of semi- randomly it fell open to her he
he flipping through found this strange
sounding article by John Bell Bel the
title of Bell's article mentioned was it
Serendipity or was it uh quantum
entanglement right we'll never know
that's right I I can't rule out either
but it was certainly not he wasn't he
didn't go looking for it I'll put it
that way it's not that clauser had
already heard about the article because
few people heard about it so by whatever
wonderful spooky actions um clauser
found John Bell's article and got very
excited this this looked like the kinds
of big you know how does the world work
kinds of questions that had attracted
young John clauser to study Physics in
the first place so as clouds recalls he
rushes back to his dissertation advisor
look at this amazing thing we could do
these experiments John Bell was a
theoretical physicist clauser was a
budding experimental physicist so Bell
had had identified a type of experiment
perform it he wasn't prepared to do it
himself CU oh we we could do that and
his advisor said that looks like you
know kind of philosophy or not what we
should be doing do this straightforward
project on very very important topic um
but do this other work and don't bother
me with these philosophical Trifles at
least as clauser remembered really just
a strong brush on so nonetheless the
topic kind of got under clouser's skin
he wrote letters to John Bell uh asking
if other experimentalists had taken it
on Bell was delighted to hear from
anyone let alone an actual
experimentalist that no one's done it
maybe you could do it that would be
amazing and so they have a little kind
of pen pal correspondence and then
slowly again through kind of Fun
accidents uh John clauser has put in
touch with other young folks the few
exceptions who also had kind of found
John Bell's article there's a group in
the Boston area uh and and a few others
so John Bell as John Claus completes his
dissertation gets a postto at Lawrence
Berkeley laboratory so to do his kind of
mainstream to continue his mainstream
research
well he gets there just to the
laboratory like most of his going
through a huge downturn in fortunes
there's lots and lots of kind of you
know spare time because the funding has
been cut way way back so he has
permission of his new supervisor new
postdoctor supervisor to spend kind of a
little portion of his time on this kind
of pet project could one design a kind
of bell test and really do it and to his
credit his advisor Charles Town said
sure you can spend some time in that cuz
you know we're not at capacity and
Charles towns went further and enabled
um a PhD a new PhD student at the time
to start working with John clauser uh
and so the two of them were able to work
on these first ever you know Bell tests
clauser recalled that he basically got
good at dumpster diving like there was
not like he got grants from you know the
federal government to do this thing it
was like what could he scrap for spare
parts and there are photographs that I
love of him actually literally duct
taping equipment together in this uh in
this kind of leftover space of the lab
um but nonetheless together um Stuart
Friedman the grad student and and John
clauser were able to do the first ever
Bell test and they found against what
clauser had hoped for uh exactly the
correlations that quantum mechanics
predicts I should say both John Bell and
John clauser hop this would be a way to
show that Einstein was right and that
quantum theory wasn't really true after
all it wasn't as true as as um as
correct as could be but there was
something maybe wrong and that
entanglement would be entanglement tests
would be a way to to to reveal that
quantum theory is not the last word and
instead ironically clauser and uh and
his colleague um younger colleague
Stewart Freeman actually found beautiful
beautiful scen results everybody wanted
to be on team Einstein everyone not
everyone but but some of these is Iconic
guys yeah yeah uh and so to to to turn
that story forward uh that so clauser
basically shared the Nobel Prize in 2022
for an experiment that he hoped we give
opposite results maybe we all make such
mistakes in the lab is pretty great so
um so that's an example of how the topic
began getting local attention now Cloud
this in
Berkeley he befriended I just want
emphasize that that was a Nobel prize
winning experiment it turned out to be
with the passage of in this his case
exactly 50 years so if you are willing
to wait you know that was it was not
seen and in fact again not only were
people still not paying much attention
to John Bell's article people didn't pay
much attention at the time to the to the
fredman clauser experiment it was
published in our most prestigious
Journal unlike John Bell's article and
yet it was again roundly ignored you can
tell that by citation analysis there's
correspondence from the time that John
claer himself shared with me and other
historian colleagues this was still kind
of dismissed by most kind of you know
mainstream physicist in fact John claer
never got the kind of position in
physics he had hoped for he never got a
university professorship and some of the
letters around his early applications
make it clear is because they thought he
was working on a kind of important
merely philosophic on a strange topic
which 50 years later you know earned a
share of the Nobel Prize um so that's
seems kind of hopefully that's humbling
for some of our department heads in the
world today anyway the point is clauser
really had caught the bug he now was
able to do this remarkable experiment
that was not getting a lot of attention
one place it did get attention was his
own backyard in Berkeley and he began
meeting up with this fundamental physics
group he was a kind of charter member
with about eight or 10 of of other kind
of new friends who all the others of
whom almost all of whom were actually
coming from theoretical physics they
were intrigued by Quantum in Tangent in
Bell's article and now they had one of
the world experts uh at their disposal
meeting John clauser and together they
met you know every Friday for years to
to kind of wrestle with this some of
them thought this might lead to things
like faster and light
communication uh and some of them
thought even further maybe this would
lead to things like an explanation from
mind reading maybe the communication is
between you know entangled particles one
of which is in my mind and one of which
is in your mind uh and so some of them
took this into even more let's say uh
new Agy kinds of directions they were
they were immersed in a kind of hot bed
of new age um enthusiasm in the Bay Area
clauser I think to his credit had a kind
of open mind about that he wasn't s of
convinced about New Age stuff but he
also said what do we know more than once
and he would participate every week and
would they would go and have study
sessions at other plac places in the Bay
Area like The eln Institute and CLA
would go time and time again and he
would say you know he he as far as I can
tell was let's say um curious but not
dogmatic in either direction some of his
his discussion mates became um much more
convinced and then maybe unconvinced and
convinced again you know there were kind
of strong ideas strong passions the
point is the group was didn't feel Bound
by what counted like to be a
straightforward question they said if
we're not if most of us aren't going to
get the kinds of careers that we wanted
anyway
and these questions seem worth pursuing
and curious they would kind of let their
curiosity drive them and they were
combine that with this really grounded
discipline study of of they could push
the equations around some of them could
do world class experiments so it's that
combination that really grabbed me of a
kind of open-minded
curiosity uh combined with the
discipline to see it through and so they
weren't just like musing they weren't
just having the late night dormatory
room chats they were open to that and
they were doing the homework right and
they were trying to say well if we take
this seriously here's what my
calculation suggest I could imagine a A
variation on that experiment they were
trying to do both and that I found
really
exciting so I hear that these
experiments really helped kind of prove
that
um that the universe is spooky that
these phenomenon seem to be real but
does did that have a direct correlation
to the um applications it sounds like
there were applied physicists already
kind of working on applications that
relied on the underlying physics um or
did this work also help Advance the both
sides of the equation I think I think
it's that it really had a knock on
effect for for both sides I mean there
weren't a lot of people at the time in
fact none that I can think of frankly
who were trying to exploit quantum
entanglement for new devices at that
time the topic was really just not of
much interest either way and so part of
what happened and partly why I got
excited to write the book was you start
seeing this early group of the kind of
eccentrics um and then with their
correspondence Network you could see a
small number of other physicists some of
whom were more had had closer ties to
the mainstream and had their own range
of you know Curiosities and interests
there's a kind of dispersed community
that begins to to talk together um some
of whom start doing followup very
brilliant followon experiments uh beyond
the the original one that John clauser
and Stuart Freeman had done and that
includes people like Alan aspe who who
then shared the Nobel Prize in 2022 a
little later it involved people like um
like Anton Zinger so there are people
and others who begin doing more
experiments um kind of riffing on the
pattern but trying to do even more
clever versions of the freedan clauser
experiment there are theorists who begin
trying to really sit with these
challenges from the Berkeley group why
can't we use quantum entanglement to
send messages fast and light if we can't
um does that help us understand other
features of Quantum Theory and new ideas
came out from that something called the
no cloning theorem was one as a direct
response to these kind of clever
provocations so you see this unfolding
again over kind of the next decade from
the mid 70s into the mid
80s and that's when you start seeing now
a kind of critical mass in a few Pockets
not still not um on the mainstream in
most textbooks um but enough people now
Beyond just this this eccentric Berkeley
group who begin wondering maybe if this
really is true of the world could we put
it to work does it become a resource and
not just a curiosity and so you start
seeing an effort to do things like
Quantum encryption which is happening
the first theoretical protocols being
formulated in the mid 1980s exactly
Downstream from a decade 10 years worth
of really trying to wrestle with both
the first Bell tests and these really
clever ideas about the relationship
between quantum entanglement
communication and relativity and so
encryption Quantum encryption becomes
really the first one of the first kind
of efforts to apply entanglement in a
new kind of device and that's actually
going yeah go ahead can you explain that
a bit how does it use entanglement in
device yeah so the idea the core idea
between behind encryption is again to
say that these uh entangled particles
share features together and so if
someone wanted to kind of um eases drop
on a signal typically for typical
signals we can we we have one source
beaming out say radio beacons and if
someone wants to kind of intercept that
radio Beacon can get a sneak preview
right uh because the radio Beacon is
sort of a basically classical system and
so what you do here should have not
won't won't show up over