嗨 大家好 我叫Mithuna
Hi everyone my name is Mithuna
and I’m a third year PhD student studying quantum
physics at the University of Cambridge.
In this video I just wanted to explain
how I got here
since what I started off in high school
I really wasn’t into science.
In fact Iquite liked art.
I mean you probably can’t
tell from the quality of my illustrations these days,
but back then I wasn’t so bad,
and I really enjoyed it and
I also really enjoyed English literature and
learning a second language and basically I really identified as a humanities student.
So what changed and how on earth did I get here eventually?
So the big turnaround came
for me when I was 16 suddenly I understood what was
going on in science class.
Maybe it wasbecause I had a really great teacher at
the time or maybe it was
because we were learning some really cool topics at
the time, but it made sense for the firsttime.
I realized that science was about
coming up with basic laws that
are simple and yet can explain so much
complex phenomena. So then
after that I picked up this popular science book
which you might have heard of.
It’s byBill Bryson and it’s called a Short
History of Nearly Everything.
I love thatbook and I totally recommend it.
finished that book I have this distinct memory
of closing it and thinking I’m
gonna be a physicist.
And yet it wasn’tsuch an easy path.
For one thing I was
still absolutely terrible at maths.
Atthe age of 13 when we start high school
we had taken a test that would show us
whether we were good at maths or not apparently,
and then according to
that we would end up in different levels of
maths class, and I was placed in one
of the lowest maths levels- in fact almost
等级最低的数学班 那些年 我都在那里学习
the lowest maths level -and I’d stayed there for all these years.
realized that if I wanted to be a
physicist I would have to do quite a lot
of maths, so I decided
that I would take the highest level of maths that they
offered at my school and I
asked my maths teacher at the time whether he
thought I would be able to do it.
Helaughed and walked away… but he couldn’t
stop me and so I did it anyway -even
though my teacher the next year really
really tried to persuade me to drop theclass.
In my final year though I had a
fantastic maths teacher and I finally realized
that actually a lot of the
things that I liked
about physics were the same things that I could like about
maths – that you can take simple rules
and use logic to be able to solve
complicated problems. I still struggled a bit
with maths and so it wasn’t my very
favourite subject. That was stilldefinitely physics. At this point I
remember I often would skip having lunch
with my friends so I could go to the
library and read physics textbooks.
In my first year
of university I did physics and chemistry along with a
second language and a maths course.
The maths course that I picked though wasn’t
the one meant for people who wanted to become mathematicians,
it was the one who
meant for people who were interested inengineering, let’s say.
I decided to do
that course because I was still
not feeling super confident about my
mathematical abilities.In that course we learned about linear
algebra which is super beautiful- I love
that you can just visualize what’s going on.
At the same time
though I was starting to feel more and more
disillusioned with physics.
Ironicallythe final nail in that coffin was
quantum mechanics in second year.
Quantum mechanics was this course that I was
super excited to do because it was meant to be
about like the strange laws that
govern physics… and yet quantum
mechanics class was mostly about solving this
partial differential equation fordifferent boundary conditions. I’d come
to physics because I thought
that I’d learned how to solve problems
but instead I felt
that I was just learning how to use mathematical formulas.
At that point I was feeling quite lost
but I got very lucky
because the next semester I decided to take a course in
abstract algebra for no other reason than
that it sounded similar to linear algebra,
which I really enjoyed.
Thiscourse was meant for mathematicians and
so in particular it was meant
for people who had taken the hard math courses the
year before and in the semester before which I hadn’t,
so I was completely unprepared.
无论如何 我还是选修了这门课它 并最终喜欢上它
I took the course anyway and Iended up loving it.
This was the first time that I’d met pure maths,
and pure maths is all about
taking axioms that describe a particular type
of system and then from those
axioms driving lots of properties ofthat system that aren’t obvious.
It had a lot
of these elements that are really liked about physics but it was
very very rigorous which was actually quite a challenge for me,
until this point I was a very intuitivekind of person.
Even in physics I would
give very hand-wavy arguments
for things and I would just think that certain
things are obviously true and
because it’s obvious to me but they’re true I
wouldn’t need to show that they’re true.
Whereas maths is the complete opposite,
and I really really did struggle becauseof that culture clash.
But it taught me
so much and I after that was completely hooked
on the pure maths way of thinking
and I decided to switch my focus fromphysics to maths.
The Bachelor of Science
was very very flexible and so I did a bunch
of other subjects as well.
decided to take a course in information theory
because thermodynamics has this
quantity called entropy in it andinformation had this quantity called
entropy in it and I was just wondering,
are they the same thing or not?
this class that was meant
for computer scientists I was the only not computer
scientists in the class and it
was so cool -no matter what discipline you’re in
I would recommend information theory.
Ithas such deep consequences for basically
every other subject of human knowledge.
In my final year of undergraduate I took
a course in functionalelseis which is basically the maths of
quantum mechanics and it’s basicallylinear algebra on steroids. I really
loved that and so I had
this crazy idea that I would become a mathematical
physicist who focuses on the maths ofquantum mechanics.
So basically I would
become a physicist just to have
an excuse to be able to do maths that
applies to the’real world’.
I’m so gladthat I didn’t end up there and the
reason I didn’t end up there is becauseof this channel.
For some reason I made
a couple of videos about quantummechanics.
I made them about quantum mechanics, I think,
just because I thought well I
understand quantum mechanics. I’ve beendoing all these courses on quantum mechanics,
surely I could explain it.
AndI loved explaining things so I just kind
of made some videos.
Those first twovideos were absolutely shocking and not
just because of the quality…
although that is pretty hard to look at now, but
also because of the content. See,
Idecided that these videos wouldn’t have
any maths in them because they were meant
for laypeople but when I have to
take away the mathsI realized I didn’t understand quantum
mechanics at all.
Sure I knew how tosolve the Schrodinger equation and I
knew what Hilbert space was but,
when it came down to what does quantum mechanics
actually say about how the world works, Ihad no idea.
That’s why when I finished
my undergraduate degree I took six months
off and started learning quantum mechanics.
Like properly learning what
it meant and as I learnt things I made
videos about them.
Most of those videosare now unlisted but I was actually
really productive at the time I made it like 20 videos or something.
journey of learning quantum mechanics
from my bedroom I met Bell’s Theorem for
the first time and started thinkingabout the foundations of quantum
mechanics and hidden variables and bohmian
mechanics and all kinds of crazy
stuff like that and I just loved it
so much -and that’s when I realized this is
what I want to do.
I want to studyquantum mechanics but properly study
quantum mechanics. Not as a mathematician trying to
just manipulate symbols, but to actuallyunderstand what was happening.
I ended up doing a honours ( which is sort
of like a one-year masters ) in physics
rather than maths and I had to pick
a subject to do my thesis in and I chose
quantum computing (and information) -not that I knew anything about quantum computing but
because it had the words quantum
and information which I already told you I
was very interested
in but also computing which I’d learnt about in a
course on logic and thought was super fascinating as well,
so I thought the
combination of these must be cool.
Andit turned out I was totally right.
computing is a fascinating field.
Seequantum computers are computers that use
the spooky laws
of quantum mechanics to do calculations faster than it should be
possible for a classical computer to beable to do them.
When this was discovered
people were really surprised
because there are many different ways to build a
classical computer and yet they all
end up being equivalent -they can all solve
the same class of problems to the same sort of efficiency –
and so it doesn’t
really matter what kind of model you’relooking at.
And yet when you make this
other model of computing using quantum
mechanics suddenly it does matter and
the class of computations
that you can do is different and so this means that
quantum mechanics obeys somefundamentally different logic to regular
classical mechanics. So there’s this
big open question in quantum computing which
is why? What exactly is so special aboutquantum mechanics?
Exactly which part of
quantum mechanics is allowing for thespeed up to happen?
That was what I was
interested in in my honours thesis.
Iobviously didn’t solve it but I decided
that I wanted to keep studying
this particular topic and that’s why I ended
up on almost the literal other side of the world,
because my supervisor here in
Cambridge is one of the people who’sreally interested in
the question and has done a lot of work
on it in the past and I wanted to work with him,
so I applied and somehow ended uphere.
So that’s my story of how I went
from someone who thought that she was terrible
at maths and science and ended
up as a quantum physicist.
If I have any moral or any advice
at all it’s that I
want you to be open-minded about the kind
of things that you could enjoy if
you gave them a go,
but also be open to minded about what you could get good at
with practice.So thanks for watching this video this
is the first time I’ve had my face
on these YouTube videos and I’m really
nervous about the comments.. so please don’t leave me anything too weird.
我妈妈会看到的 开玩笑的啦 我妈甚至都不看我的视频
reads them. I’m just kidding she doesn’teven watch my videos.
Anyway you know
what I mean.
Also the video
about Hilbert space and Dirac notation and the maths
of quantum mechanics- I’m writing it
right now and that means that it should
be coming out soon which means that it should be coming
out within the next two months,
probably. Hopefully sooner!
嗨 大家好 我叫Mithuna