
How to become a good theoretical physicist - apsec112
https://www.goodtheorist.science/
======
knzhou
This is cool as always, but in case anybody is seriously contemplating using
it: this list is infamous for its complete uselessness for anybody actually
trying to learn. It's mostly recommended because of 't Hooft's name, but it
doesn't reflect how he actually learned physics himself, nor how anybody ever
has, really.

It's been "under construction" (i.e. completely abandoned) for two decades.
Half the links are broken, and the ones that aren't tend to be whatever the
top Google hit was in the 90s, not what's pedagogically best. If you're
serious about learning physics, there are many much better roadmaps, like
Susan Fowler's list ([https://www.susanjfowler.com/blog/2016/8/13/so-you-want-
to-l...](https://www.susanjfowler.com/blog/2016/8/13/so-you-want-to-learn-
physics)).

~~~
fizixer
I'm sorry I can't take Susan Fowler seriously. She claims she went from zero
math knowledge (besides sixth grade) and a philosophy major to studying
quantum field theory in a span of something like a year and a half [0].

If this wasn't horsesh*t to begin with, she went on to work in non-physics
areas after graduation, and never did any research work in physics (no grad
school either).

How convenient.

(likely explanation: either her undergrad program was super lax, passing
pretty much everyone who shows up in class and exams, hence useless for a
serious career in physics, or she's misrepresenting her background)

[0]
[https://web.archive.org/web/20170314073043/https://fledgling...](https://web.archive.org/web/20170314073043/https://fledglingphysicist.com/2013/12/12/if-
susan-can-learn-physics-so-can-you/)

~~~
knzhou
Well, I've read almost all the books she lists and I've been a quantum field
theory practitioner for years, and I can at least attest the list is good.
People actually learn from these books.

I think your comment also directly illustrates what I was complaining about.
You really shouldn't source learning recommendations from the highest ranking
people, because these people know the least about what it's like to learn
something anew. A Nobel prize doesn't automatically make somebody a good
teacher.

~~~
mnky9800n
Carl Weiman would like to have a word with you. Ahahaa.

~~~
jimhefferon
Not GP but if you mean that

> A Nobel prize doesn't automatically make somebody a good teacher.

is mistaken by pointing to Weiman, could you elaborate on that, please?

~~~
mnky9800n
Carl took his nobel money for BEC and started a career in education and
education research.

~~~
jimhefferon
Sure, he is admirable that way. But the comment says not necessarily, which is
not a throwaway. Personally, it seems to me that being good at teaching is at
the least independent of being a good researcher, if not perhaps negatively
correlated. That very much does not rule out extraordinary exceptions (ones
that deserve a great deal of attention, for sure).

~~~
mnky9800n
I just think they are not correlated. Both require you to put effort into
being good at it. They also require you to have a firm grasp of the source
material.

------
mnemonicsloth
I am working on something like this myself. I started by reading the Structure
and Interpretation of Classical Mechanics, which uses Scheme to teach
Hamiltonian and Lagrangian mechanics. And it's much more effective than an
ordinary math/physics book. Normal math is a kind of code, except that the VM
that executes it is your brain. You (or I, anyway) can only progress if you
understand absolutely everything down to the last detail. Programming is much
easier. If you don't understand something you can put together a little
simulation to poke at the edge cases.

So I finished SICM and I thought, "wouldn't it be cool if I could keep
learning physics like this?" And so now I've gotten in touch with some physics
postdocs (who are paid shockingly little). I pay them to learn Scheme and
encode quantum mechanics, general relativity, statistical mechanics as scheme
programs. I work on this about 10 hours a week. In a year or two I'll have
knowledge equivalent to an ABD physics grad student, plus information that can
take other people from modest beginnings to the same level.

One thing this project has taught me is that students have shockingly little
power in their relationships with teachers. I am a major source of income for
my postdocs. Some of them may be prioritizing me over some of their other
duties. And it really shows. I'm a good self-learner, but there is no
substitute for having someone work really hard to anticipate all your
questions.

Another thing I've noticed is that everyone (except, increasingly, my
postdocs) is a terrible teacher in academia. I have a friend, a fellow grad
student, who is scheduled to teach her first lab in her first semester. The
lab meets Tuesday. The one-hour credit-only class that will supposedly teach
her how to teach meets Wednesday. On day one she'll be going in completely
unprepared. And she's not atypical. I suppose that, since students have no
power, few people care whether they learn well or just adequately, so people
(administrators, professors) prioritize other things. The glaring exception to
all this proves the rule. The one person who has done the most to make me
successful in graduate school has been my advisor -- and his name will be on
every paper I publish. (I like the guy a lot, but self-interest plays a role)

~~~
mhh__
Obviously to each their own, but I find almost all attempts to use anything
other than mathematics a needless abstraction for the most part. Being able to
poke and prod is useful, but if you do the exercises you shouldn't need to for
the most part. Tensor Indices are a bit tricky at first but most notation has
evolved for a fairly obvious reason.

Complaining about mathematical notation is quite common on HN, but
realistically it's by far and away the easiest part of learning physics (and
that's not including _gasp_ actually doing experiments properly). If you
aren't planning on doing research I guess it doesn't matter but it's worth
keeping in mind that if you learn everything via Scheme or what have you, you
may end up in Rome doing as the greeks do.

Cool project nonetheless.

~~~
BeetleB
As someone coming from the physics side of things, I was about to post a
similar comment myself. However, what the commenter is trying to do actually
provides value in a way most physicists haven't experienced. I agree it'll be
hard to get far if you keep avoiding mathematics, but I also think that if a
physicist can't program it in a way this person can, then that is indicating a
deficiency in the physicist. And I don't mean that to emphasize the
_programming_ aspect, but more that it's easy to find physicists who become
good at doing the math but not so good at the actual physics, and get by
merely with mathematical manipulations.

~~~
mnemonicsloth
I'm not avoiding mathematics. I used to be a mathematician. The math is the
whole point.

In the mechanics library that comes with the book (which I'm building on in my
own work), functions can take either numerical or symbolic values. If you have
a computation involving symbolic values, you can manipulate it just like you
would with pencil and paper (except you can operate at a higher level of
abstraction, never get writer's cramp, and never have to laboriously recopy
line after line of symbols to make sure you got the right number of minus
signs). If, as so often happens, you find yourself up against an intractable
integral, you pass the whole thing to a numerical solver and get a number back
right away. With enough calculations you can build up a qualitative
understanding of the system's behavior. My understanding is that this is what
mechanics people do all day, but not how mechanics is taught to newcomers.

------
wintercarver
I studied physics as an undergrad and then went on to get a PhD from UW
(Seattle), which has required courses for physics education that all graduate
students must take. With ~10 years of physics study/practice/teaching, I think
the one meta lesson I've carried with me is it's not about which book or which
method, but rather the marathon process of ongoing exploration, which is often
fueled by genuine interest and joy in exploring the subject. Exploration here
applies to the subject itself in spirit, but in reality means exploring the
resources to gather perspective and understanding.

The above probably sounds obvious (sorry!), but a lot of learning
recommendation seems to focus on "the best" resource, which in my older years
strikes me as kind of odd. In the grander scheme of studying something in
earnest, time spent with any one book will not be the determiner of success.
That's not to say there are no great books or resources, but rather if
something is hard or not making sense you should try to approach the topic
from another angle: read the chapter on the same topic from another text, or a
few others, find some alternative lectures online, etc -- these days the
resource list is near limitless... So, start somewhere, don't worry too much
about how you start, and keep going!

A lot of the above opinion was motivated by a kind of serendipitous
conversation I had with a physics professor. I returned to that convo often
enough that I finally decided to write it down last year. Pardon the self
plug, but intent was to help share a learning perspective:
[https://medium.com/@kevinconnolly/effort-neglect-and-the-
sec...](https://medium.com/@kevinconnolly/effort-neglect-and-the-second-
textbook-434a3400be2f)

~~~
kinleyd
'The Second Textbook' is a nice perspective which resonates with me. In my
experience I've found the need for as many textbooks as I can get my paws on -
each book usually handles one or other topic better than others, or gives me
that extra angle that helps my understanding.

~~~
wintercarver
Yeah, and there is path dependence in learning, too! The Feynman lectures are
quite deep and insightful, but because of that probably good to circle back to
at different times, as an example.

But the real kicker for me was just breaking through the impression that
“understanding” is a function of rereading, getting stuck, and focusing on
_one_ explanation as if parsing the syntax of some author’s statement was how
you got information and understanding of a subject. My general rule now is to
simply read different explanations. That, imo, is how you develop pedagogical
awareness, too, as you then begin to see what authors are _not_ saying in
their attempt to convey a subject.

Anyway, thank you for reading and the comment!

------
gpsx
Gerard 't Hooft knows a thing or two about being a GOOD theoretical physicist.
But I do have one general complaint about what he is saying. It is apparently
common for people, especially ex-physicists like myself, to think they have
figured it out (whatever "it" is). In reality, they just forgot (or never
knew) enough to realize how bad their idea is. He pretty much agrees with this
and his solution is for people to learn it all. In _general_ I don't think
it's fair to say you have to be an expert to contribute. We wouldn't make any
progress if nobody was allowed to make a suggestion unless they were an
expert. This would pretty much silence me (in things not related physics, such
as software, or if I was so inclined, in physics too).

Now, I am being a little unfair. I think it is great what he is doing. AND, if
anyone does think they have solved the secrets of the universe, don't take it
to one of the top physicists in the world before checking it out a little more
humbly.

But in any oher case, just throw caution to the wind and don't worry if you
don't know everything.

~~~
mnemonicsloth
_He pretty much agrees with this and his solution is for people to learn it
all._

I thought 't Hooft was saying you have to learn all of this stuff. But it
sounds like you're saying you can do good work in physics without some of this
information. Is that true? What can you dispense with?

~~~
gpsx
No. I wasn't trying to say that. He is right that there is a lot to know to
make any contribution to physics. I was trying to make a more general comment
that people shouldn't be afraid to try something even if they don't know all
the background. Make mistakes and learn as you go. That applies more to "easy"
things like software.

------
jjdredd
I think the author is missing a couple of important points:

1) How would one approach this task having a day job?

2) How do you compensate for not having a chance to work in a suitable
environment doing good research?

2a)Knowing and understanding everything that has been done in the past doesn't
by itself make you a researcher. This (being a scientist) must be taught by
actual theoretical physicists. There are many supervisors, but very few that
can teach you to do research.

2b) Serious and worthwhile research is seldom done by one person. You need to
collaborate or at least communicate with other scientists in the field (and
sometimes even out of the field). You have to be in the right environment.
Just reading arxiv won't quite cut it.

------
eointierney
Or how to become a better theoretical physicist.

Generality and technical ability, proper mathematical awareness, historical
understanding and appreciation of our forerunners. Mainly read the damned
texts and task good teachers when confused. Go hard, go long, never give up.
Seek elegance. Don't be afraid to disagree but always be rigorous. Play well
with others.

Ask the ancient questions and think better.

I don't have a Noble prize for Physics I just study the work of those who do

------
pontus
Oh man does this bring me back! I used to view this list as such an
aspirational goal.

Honestly though, if you want to become good theoretical physicist you pretty
much need to go to grad school.

------
grendelt
> "...in theory."

Amirite? Guys? Hello? Guy? Is this thing on?

------
mrwnmonm
This was my dream :(

Anyway, I like to mention the book Deep Work, I think it is essential for any
science student in our age.

------
mhh__
It's also worth adding that these days libgen has almost everything _wink
wink_.

------
abhayhegde
This list is barely updated. New texts and standards have emerged, and gives
no insight as to how to develop the analytical skills. Just a list of books
won't do.

