Hello, and welcome to the Physics World weekly
podcast.
I'm Hamish Johnston.
In this episode,
we explore how pictures
can be used to teach the fundamentals
of quantum physics
to everyone.
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Today, quantum physics is enjoying a renaissance
in science and technology.
After decades of speculation,
quantum computers are now real things, and quantum
sensors are being used in a wide range
of applications
from underground
surveying
to measuring brain activity.
As the technologies
we use become more quantum in nature,
it follows that everyone should have a basic
understanding
of quantum physics,
something that today remains mostly the preserve of
scientists,
engineers,
and mathematicians.
To explore how quantum physics can be taught
to everyone,
I'm joined by Arjun
Dovin,
Alex Kissinger, and Bob Kuka,
who are all based in The UK.
Bob is chief scientist at Quantinium,
which develops quantum computing hardware and software.
Alex is associate professor of quantum computing
at the University of Oxford,
and Arjun is studying mathematics
at the University of Durham.
Alex and Bob have developed a way of
teaching
quantum physics
using diagrams.
And in 2023,
Oxford and Quantinium
joined forces
to use this method in a pilot summer
program
for fifteen to seventeen year olds,
and Arjun
was one of their students.
Hi, Alex, Arjun, and Bob.
Welcome to the podcast.
So, Bob,
could can we start off
by,
having you explain why the time has come
to teach quantum physics to everyone,
not just physics students?
So what's happening at the moment or is
about to happen, and people should have noticed
this, I guess, if they're listening to a
podcast like this, is that we're, like, on
the verge of
a a technological revolution, which is gonna be
the quantum revolution. Some people call this the
second quantum revolution after what happened, of course,
in the beginning of the previous
century.
And and
so
this is gonna impact,
many aspects of our life,
very soon for many people. And so you
want some form of inclusivity
with respect
to people knowing what is going on.
So it's usually, quantum is conceived as something
that
you need a university degree and and or
a or a PhD to understand.
And now we have the tool at hand
for, like, a much broader, like, portion of
society,
even not everybody, because we like to say
quantum for everyone,
can actually understand quantum and grasp the basic
concepts.
That's basically what this podcast is about. Some
work,
Alex and I did, some experiments with it
a little bit back to show that what
I'm claiming here is actually true. Now inclusivity
means, for example,
that people students can learn this at high
school or later, but also that people in
countries which are usually not that much subject
to to technological things, like in Africa,
also can be part
of this gig. And maybe that's something that's
gonna come up later in this in in
this chat. I actually believe that some non
Western countries actually have an advantage now to
to be inclusive. Now another thing is I
mean, I was asked to speak at the
US capital because this is case of
workforce
preparation, like making the workforce much bigger for
quantum, which is also necessary.
And I would also bring in accountability here
because of what we are seeing now with
AIs. Nobody has a clue what's going on.
And that's not very healthy,
especially if only a few people in the
world with a lot of billions can make
all the decisions while nobody else knows what's
going on. So that's the last one. And,
I mean, as as a last command, I
would say, quantum comes with a radical shift
in worldview, in the way we perceive the
world, not in contrast to classical physics, but
I would actually take this back two thousand
five hundred years to the presocratics. But maybe
we can talk about that later.
I see. And and, Bob, this is, I
mean, this isn't just a concept for you.
You,
you have spent a lot of time,
trying to come up with ways of of,
I suppose, teaching
quantum physics to to non physicists,
to the to the general public. And and
one thing that you've done is you've coauthored
a book called Quantum in Pictures.
And that takes a a graphical
approach with no sort of conventional
equations
to teach quantum physics to a wide audience.
Can you describe the the approach that you've
taken in the book?
I mean, this was a very long process.
And,
so so my background historically,
going back to the nineteen nineties,
is is kind of more with a new
language for quantum over or a new mathematics
for quantum. And this goes back to a
question
of John von Neumann post in nineteen thirty
nineteen thirty five when he based John von
Neumann is the father of the usual quantum
mechanical,
formalism, Hilbert space, also being the father of
the computers we're using here to talk, by
the way. And he denounced his own quantum
mechanical formulas in 1935.
So I came from a culture, a community
where we try to come up with something
new.
And then I was very lucky to actually
with a background as a physicist to end
up in a computer science department
in Oxford where where Alex now is a
is a professor. I used to be a
professor there.
And then
new ways of viewing at the world came
from computer science, which are more about thinking
of things in terms of processes and thinking
of things in how
stuff composes together, which are very fundamental computer
science,
concepts which a physicist would typically not think
about in first order. And that basically gave
a completely new view on how to build
a quantum mechanical formalism.
Our first idea was basically to build the
formalism
as a high level language for quantum, just
like any programming language is a high level
language for zeros and ones in your classical
computer. And we want to do the do
the same for quantum, but then very early
on, I mean, we I started this in
02/2003, '2 thousand '4. In 02/2005,
we realized
that the language we used were actually pictures.
And these pictures go back to Roger Penrose.
When Roger Penrose was an undergraduate student, he
actually had to ill and he had to
learn relativity theory.
He basically realized that the symbols you typically
use in relativity theory could be But
it was only in the late nineties that
people realized that it was actually gen genuine
mathematic. And then over in a process of
twenty years, we've a great involvement with with
Alex. We actually ended up with a formalism,
which was entirely
diagrammatic. The first the first subject were actually
the students at University of Oxford,
like postgraduate students. So Alex and I, we
together started a course. And in the process
of the the the textbook of this course
is now a book called, Picturing Quantum Processes.
It's thousand pages.
And so but then
that book was not suitable for people without
the right mathematical background. And then later,
we basically,
wrote this new book where we said, okay.
There shouldn't be any a requirements
in there anymore. So I'll end up, I'll
end over to Alex who's now more hands
on on these things.
Yeah. So I've I think, really, for me,
this started back around 2012
or so, when when Bob and I revamped
the quantum computing course here.
So during my PhD, a lot of this
early stuff about processes and things that Bob
was talking about
was all formalized using a kind of mathematics
called category theory,
which which is just a very abstract way
of talking about
processes in a general sense.
But sort of toward the end of my
PhD, we realized that the mathematics there wasn't
so necessary, and you could sort of pull
that out, teach everything with pictures.
And then over about a decade of me
and Bob teaching this course, we were teaching
people from a lot of different backgrounds, so
not just physics and maths,
but also engineering and some social sciences and
stuff, and realized that that you can actually
teach quantum concepts to people, you know, much
more broadly
than that. And, I think that, that Bob
and Stefano's book and then and then this
experiment that we did last
year with high school students was kind of
the natural
next step in that in in in making
that a bit bit more broad.
I see. And and in quantum mechanics is
I mean,
is there a a sort of long tradition
of sort of simplifying
things by well, maybe not simplifying is is
is not the right word, but
expressing things in terms of
images or,
diagrams? Because, you know, I'm sort of thinking
of,
matrix,
mechanics, and then you've got Dirac notation
and Feynman diagrams. There, you know, there seems
to be a a real desire amongst physicists
to use graphical means to understand
quantum physics. And, do you see the these
pictures as a as a natural evolution from
from those concepts?
Yes and no. Like, know whether the desire
is there.
Because, I mean, one of the big, well
known examples are Feynman diagrams.
So which Feynman diagrams are a calculation
tool in quantum field theory to make your
com computation much easier. Feynman had to fight
really, really hard to get him through. Although
now everybody sort of assumes, okay. That's that's,
like,
totally straightforwardly
acceptable. No. It wasn't like that at all.
And when you mentioned direct notation, I remember
I was a student in the in the
nineties in a mathematical physics, theoretical physics group.
People looked down on direct notation
because it didn't have the sort of
what they assume sophistication
of the infinite dimensional
complicated stuff. Okay. I'm gonna say something sociological
here.
So so the science as we know it
physically is a very much used to be
a very much white male dominated thing with
a lot of ego and machoism.
And so when I was a student in
the '90, it was really about
the more complicated it is, the better.
And we had to fight really, really hard
to push this formalism through in the mainstream
communities
exactly for the reason that I said. People
said, this can't something simple like that can't
be useful
in any way. Now meanwhile
and, actually, Alex is more active in in
that than me. All the main players in
quantum computing, quantum industry, they're all using this.
Now it's so widespread, but it took us
so long to fight and to get,
things things basically published and and accepted. And
part of the thing we had to do,
which is what Alex alluded to earlier, is
to use this abstract mathematical language of category
theory to make it look more difficult than
it actually is.
And that's how we got our papers accepted.
We had to get rid of that stigma
of of this category theory, and that's why
we wrote the big book because there was
no mention of category theory anymore.
Okay. And I'd like to move on from,
from from books into teaching.
And in in 2023,
Bob and Alex, I believe you you're both
involved in a
ten week summer course of short lectures
that taught British teenagers, I think, age 15
to 17,
how to apply the the concepts in quantum
in pictures.
Alex, can you tell us about that course?
Yeah. So this was a course. It was
also a kind of a pilot experiment for
this this style of education.
So so it was a team. It was
the project was jointly done by Quantinium and
Oxford Computer Science,
where we took,
in the end, about 50,
UK High Schoolers,
from a pool of about a thousand people
that volunteered,
and gave them a course,
as as close as we could kinda within
our constraints
to a
Oxford Cambridge style
graduate graduate course.
So it was eight weeks of lectures,
along with small group,
tutorial sessions. So this was all done online,
and then followed by a,
take home exam.
So,
the lectures were prerecorded and shared with the
students on on YouTube.
And then the and then the small group,
tutorial sessions were were just, like,
Zoom chat type things.
So it was it was it was intended
to be a kind of a interactive thing,
but then but then also to to get
to give a bit of this, sort of
university style experience.
I see. And and we've also well, we
we're we're very lucky to have a a
graduate
of that summer course with us, Arjun.
Why did you,
decide to take part in, in this course?
Did you did you already have an interest
in quantum physics? Or were were you just
curious to,
Why did you sign up?
Yes. So I think it's probably more in
regards to the latter part. I I would
say I became, like, fascinated with quantum physics.
I remember at that point, I had just
finished year 12, and,
I took a level physics. So by the
summer term, we started doing quantum phenomena. And
I remember specifically, it was,
we did this experiment with, I believe it's
called, like, an electron gun, and we were
looking at electron diffraction.
And I just thought, like, the concept of,
like, wave particle duality was just so cool.
Like,
I thought it was definitely something I would
I would find fascinating, just the fact that
it's so new and it's so unusual.
And so I suppose that made me aware.
And then it was actually my friend who,
was recommended the course
by his teacher. So then he sent it
to me and suggested, like, overshoot this together
could be, something fun.
I see. And and what did you enjoy
most,
about the program?
Well, I I would say first thing, the
lectures, it had to be Bob's,
like, use of props and, like, just funny
intros. That's always great. I remember we had
this amazing skeleton and the spiders. That was
always fun.
But I I suppose I actually enjoyed just
getting more into
the whole, like, making algorithms with
the diagrams.
And I suppose it's just a different way
of thinking because,
I mean, from school, I would never would
have thought of using pictures to do math.
I always would have kept separate ideas. So
I think that in itself was quite interesting.
I see. And and was it fun? Was
it was it a fun thing to do,
or or was it hard work, or was
it a bit of both?
I'd say a bit of both. Like, it
was definitely enjoyable throughout.
It did take some time to get used
to.
Although, interestingly, I feel like these are pictures
that feel quite intuitive because it's something, I
guess, you can
conceptualize a lot of the times.
I did feel like I did have uncertainty
as to whether
what I was doing was actually correct. So
I think, initially, I did struggle with being
confident in my ideas, but it did feel
pretty intuitive, I'd say.
I see. And and did did you have
much contact with with your fellow students?
Did did you get an idea for for
who they were and and and why they
were there?
Partially. I suppose,
mainly contacts was
through tutorials.
And so I guess there was a there
was a range. There were some people who
would love to, like, also speak up and
we can engage, and some who are more
reserved.
I suppose, Bob, do you have something you'd
like to say? Yeah. Bob, go ahead. So
so we had a lot of restrictions
imposed on us because we were doing an
experiment with minors. So one of the things
we wanted to do is a lot more
social media so that students could interact with
each other, but we were told, no. Not
do that. And so it was quite a
bunch of restrictions
that we were imposing
on us to the extent that at some
point, I said, no. We are just gonna
pull it because this is not a normal
teaching experience. And then Alex convinced me to
to keep going because I thought, okay. This
is not gonna work. This the results are
not gonna be good because this is not
a normal I mean, I should say something
else, and I don't want to embarrass Arjan,
but like, most of the students just had
a black screen.
And and they didn't ask questions. They typed
questions. And then I wrote, like, an email,
a long email saying, please, please, show your
screens and speak. Because as a teacher, we
need to see your facial, like, articulations.
We need to hear the tone of your
voice because that's part of a teaching. Teacher
teacher student interaction. And I think for, yeah,
five seconds, some some screens went down, and
then they were back again.
So so it sounds,
Arjun, that,
the the sort of remote nature of it
was a bit difficult. Or or or I
don't know. Maybe maybe you were happy with,
with that. Or is there anything is there
anything else that you'd add, to what Bob
said in terms of how it could have
been improved? I mean, I'm guessing
actually going to Oxford,
if that was possible and and doing it
in person would have been fantastic, but maybe
not possible.
Yes. I think,
overall,
I suppose, just naturally teaching online is a
bit like, it can be quite in person.
And I guess as Bob said, not many
people did always turn on their cameras or
respond.
I just feel bad sometimes for some of
the tutors because we had that awkward silence
for a couple of seconds.
Mhmm.
But, I mean, I I suppose some benefits
was that sometimes I would I would be
able to message my friends and we could,
like,
we could discuss things,
somewhat freely.
But I guess that, that was not to
the benefit of the tutors because they have
no idea what we're discussing.
But yeah. So so I think just the
online like, as you said, being in person
would have been,
perhaps a bit more
invested. But yeah.
And and so what's your view on quantum
physics,
after having taken the course? Are you
I I I understand you you're at university
at the moment.
Are are are you doing physics? Do you
do you plan to pursue a career in
quantum science and technology,
or have you have you put your interest
on the back burner?
I would say yes. I, like so I'm
currently studying mathematics,
but
it was one of my intentions to actually
do,
like, the quantum modules within my second and
third year. So I'm now coming towards the
end of my first year. And,
yes, I thought, and I thought it's one
thing because I do remember speaking to lots
of tutors about, like, as, I guess, Bob
said, like, there's lots of a mat, maths
towards it. And I thought perhaps by doing
just maths, then I would be able to
understand those, like,
I'd be able to read more literature and
perhaps have better understanding.
And so, yes, I mean,
I would say I haven't done much more
in terms of the extracurricular side.
But I think just also seeing the possibilities
throughout the course,
like, just creating algorithms
seemed fascinating to me.
I remember I think they did mention one
about solving prime numbers
or, like,
factors
like prime factorization
using,
like, quantum algorithms, I thought was really cool.
I see. And you as a you you're
doing maths at university, but
it I mean, for maybe for the benefit
of of of high school high schoolers who
are listening and thinking, should I do physics?
Should I do maths?
Do you have the opportunity to do
physics
as a mathematician? You know, for example,
doing,
mechanics and and quantum physics.
If you wish, can you can you study
those things in your course?
I suppose yeah. So currently,
I just wanted to just show some mathematics
I can. I think in the first term
in the first year,
a lot of the content is kind of
pre cited. You get at least at Durham,
we have one optional module.
But then I don't think that goes towards
quantum. It's only as within your second year
where you could start to specialize more towards,
perhaps, like, quantum modules,
mechanical modules, statistics probability.
So I suppose definitely later on. Although, I
do guess there's also the option of natural
sciences in which,
we can choose a combination of
subjects. I like to do maths and physics
as as an option.
I see.
And and what about the future? Do do
do you see a a career in quantum
science and technology
in in your future,
you know, after you've done after you've finished
with university?
I would say
probably, definitely,
yes.
Because I think
the quantum space seems to, like, encapsulate all
of my favorite subjects. Because for instance, for
a levels, I did math both math, physics,
computer science. I guess quantum computing
is, in a way, all of those.
So
I think
also perhaps
because it's so new, I think it's something
that would always keep me interested.
So I think something I would always be
enjoyed and pretend doing
regardless.
I see. Good good stuff. And,
I mean, obviously, the the summer course has
been,
well, Arjun has you've really enjoyed it, and
it's encouraged you to to look at quantum
science and technology
as a career. But but, Alex, I understand
that it's it's not just Arjun who's who
did very well.
You you you had, you had the students
sit a university level exam
on quantum physics at the end of the
course, and,
I think you were extremely pleased with the
outcome. What what happened, Alex?
Yeah. That's right. So so at the end,
we gave them an exam which had all,
previous,
exam questions that that Bob or I have
given on an exam to master students in
in past years. So we just sort of
put that together,
adapted a little bit to match the terminology
of the course, and just gave that exam,
really having no idea,
what we're what we're gonna get back from
this.
And
we're pleased to see that most of the
students passed and,
something like forty percent,
or, yeah, around around that actually got distinctions
or or first class marks and things.
So so, yeah, that was really great.
And one of the things I noticed
kind of qualitatively when marking the exam is
that some of the students understood
certain concepts and
possibly even
even in a better way than I see,
with the graduate students.
So so really an example of that is
this idea of nondeterminism,
in quantum theory. So for instance, I do
a I do a quantum measurement. It collapses
my state, and I I don't get to
control
what state it collapses to. Right? So the
quantum theory has this idea of this kind
of irreducible
nondeterminism,
and quantum computing
really uses this in in the way that
it designs some things. Right? I do a
measurement. This has some sort of action,
and I have to account for that in
a certain way.
And I saw in the way that that
many of the students answered these questions that
they that I think they understood that in
a way that
that was sort of more fundamental, I would
say, than than
than than some university level students.
That that could be that they they aren't
as accustomed to a more traditional or
classical
way of thinking already that a computer scientist
or physicist would get in in in university.
And, Arjun, did you enjoy doing the exam?
I mean, maybe enjoy is the wrong word.
But,
did did you, did did you find it
was it a nice way to end the
course?
I think so. I mean, I'm very reluctant
to say I enjoyed an exam, but,
it was definitely nice to have,
I guess, more like, because I think one
of the things is, actually doing lots of
questions were really interesting because it was a
way to practice and actually apply what we
had learned.
And,
I guess the exam
was definitely a nice way of doing it.
And, gosh, I'm trying to remember exactly.
It's been a while. But
I think,
I I mean, I remember
slightly struggling with it initially,
because it was once again, it was one
of those things which is uncertainty. Like, how
how right is my answer? How correct is
it? But,
no. It was definitely,
interesting and
enjoyable.
Oh, that's great.
And,
and, Bob,
final question,
for you.
Do you think that a version of the
summer course could be integrated into
a high school physics curriculum.
And may maybe that's something that that you
and Alex and your colleagues are working
towards now. Is is that something that we
could see?
It is already happening, actually.
Like,
Greece
was the first country to basically start using,
this this language methodology
at high school level.
So that there is a translation out now,
which was really pushed by by the the
the mathematics
sort of teaching
council in Greece.
So, I mean I mean, it's probably not
an accident that it's Greek because
as I was hinting at earlier,
this language is not something you contrast with
classical physics. I think this language basically goes
back to before 2,400
of western scientific tradition
to the pre Socratics in Greece.
Because that's the moment when western science decided
to become mainly
it, reductionist
following Democritus
and having quite a static kinematic based view
following a guy called Parmenides.
On the other hand, you've got people like
Heraclitus who had, like, a process based view
on reality,
Leibniz who has, like, an interactive relational view
on reality. And these pictures, without
people probably realizing it, they are much an
embracement of a post process based view and
an interactive view. And, so so so something
Alex was hinting out, about, like, they didn't
the people maybe not have been much as
much as subjected
to, like, western thinking may actually be an
advantage. We kind of saw that the 15
year olds were doing better than the 17
year olds, which kind of proved that point
that the less you've learned,
the less you have to unlearn.
And that's in particular why I think it's
really important to start this stuff very early.
And,
I got a few people now working on
this. Like, we're we're we're talking to many,
many places in the world, like, where they
want to start
this in a pro so one country is,
like, wanting to do high school, teaching
using this is Ghana,
for example. So and, we we also have
a collaboration which is now now funded with
Colorado
Colorado state schools.
So several places in the world are starting
to,
have we we we are doing an Ukrainian
translation, by the way, too, on the initiative
from Ukraine
of of the book. So lots of places
are now starting to want to integrate this,
But it it's all quite recent. You know?
So it's a very ongoing process, and I
expect if we speak in a year about
this, their story will be much more advanced
and much more, yeah, broader in where and
when this stuff is being, integrated in high
school curriculum. But it should be. It should
happen. It's not just about quantum. It's about
a changing world view to a more relational
and process kind of
way of thinking, which which also makes the
the sciences and humanities a little bit closer.
I see. And and what about you, Arjun?
I mean, you're out of all of us,
you're the closest to to having been in
high school.
Do I mean, do you would you have
enjoyed,
seeing this material,
you know, when you're doing your
physics a level or
a mathematics a level or even,
at a lower level,
at a younger age in high school? Do
you think it would be it would be
very useful?
I'd yeah. I definitely think so,
because
I think it's something that could,
it could be like a nice way to
kind of unite, I guess, physics and computer
science. So for physicists and computer science students,
it, I mean, perhaps creating some algorithms where
they're, like, perhaps more
simplistic, could be nice. And then also, I
suppose that,
it would probably make people more aware,
of just, like, a small if I call
it physics, I guess, by
just,
giving more exposure.
And so, yeah, I think it definitely would
have been nice.
And I think also,
as both Alex and Bob Sway were saying,
by at that point, we've learned less classical
way of thinking,
for math and physics. So it would be
it would make that easier more intuitive.
I see. And and maybe I'll I'll throw
this out to to Alex,
first.
What about even younger children
and,
you know, people who have done finished their
schooling?
You know, I'm thinking of primary aid primary
school age children
and,
just just the interested public. I mean, is
there a is there an argument for introducing
or coming up with ways of introducing
quantum physics,
to to those groups of people.
Yeah. I think I think so.
I mean, the,
the original paper of Bob's that kind of
kicked off this education idea was titled kindergarten
quantum mechanics,
which I think was a bit of a
tongue in cheek title that, you know, we
could teach quantum mechanics to kindergartners. But, I
mean, I think it it'd be interesting to
see just how far we can we can
push this. And I I think for instance,
you know, I know anecdotally cases of 12,
13 year olds reading reading Bob and Stefano's
book and getting a lot out of it.
So thinking about different different levels to pitch
that at and also also having more materials
that, you know, you can just share with
your friends. Like, so for instance, if people
are interested in pop science, but they don't
have a mathematical background, they can sort of
this kind of stuff, you can get your
teeth into in a way that you can't,
with a pop science book because here, you
know, we give you something, and you can
really do some calculations. You can see what
quantum theory is gonna tell you will happen.
And I think that could be really appealing
to a lot of people.
Okay.
Well, that's great, guys. Bob, Alex, and Arjun,
thanks so much for,
speaking to me. Arjun,
best of luck with your career
in mathematics and hopefully,
quantum science and technology.
And,
Bob,
hope everything's going well at Quantinium. And, Alex,
best wishes at Oxford. And thanks so much
to all of you for coming on the
podcast.
Alright. Thanks, Hamish. Thank you. Thank you. It
was a pleasure to speak to you.
I'm afraid that's all the time we have
for this week's podcast.
Thanks to Bob, Arjun, and Alex for joining
me today, and a special thanks to our
producer Fred Isles.
I'll put links to Bob and Alex's books
in the notes for this episode.
We'll be back again next week, but in
the meantime, do check out the latest episode
of the Physics World Stories podcast,
which features an interview with Linda Williams,
physicist,
performer,
and self styled
physics Chantouse.
She tells host Andrew Glester about her latest
show called Atomic
Cabaret,
and they chat about how she combines science
with music,
satire, and performance art.
That episode is called the Physics Chantouse,
when science hits a high note, and you
can find it on the Physics World website
or at your favorite podcast provider.