Monday, June 30, 2014

Justin: unemployed

Dear Diary,

Justin's employment was terminated today.  He will now be working for the American taxpayer via the National Science Foundation as he won the prestigious Graduate Research Fellowship.

Fly little bird!  Spread your wings and go wherever the wind may take you!  He's now up in a big office on the second floor with the postdocs and other funded students.

The rest of us have to keep working for Kieron in the basement...Kieron also mentioned something about this being a lesson for the rest of us (eek!).  I'd better get to work!

Friday, June 27, 2014

The Quantum Spin Explained

Dear Diary,

I had these grand plans to figure out what exactly the hell a spin in quantum mechanics came from.  It's this little physical fact that only has a finite number of configurations (like 2: can be up or down...weird!) and every electron has one that interacts with magnetic fields.  But it isn't clear in physics texts that there's a better physical description other than it is measured.

I swear I had this idea that you could get a spin from the path integral semiclassically and evaluate motions with electrodynamics involved.  I even went so far as to ask Raphael a few months ago if you could get thermodynamic properties of solids from the path integral to coyly ask if you could do it with a charged particle and a spin.  Wasn't I clever to have outsmarted really, dangerously smart people from hundreds of years of staring at math on pieces of paper?

But blast!  I've been scooped by several decades!  Those old physicists are crafty foxes, they are!

It turns out that the American Journal of Physics ran an article by Ohanian (author of a widely used book on physics) in 1986 that explains exactly how a spin comes about from the electromagnetic field which summarizes previous efforts to do so by Belinfante.  It's actually pretty simple!  Using a few conservation laws and Dirac's equation, it comes out that photons have spin 1 because of the way electromagnetism works.  Meanwhile, if you quantize things, electrons get the half spin, just like I wanted to show!  Basically, it's a consequence of the electric field from the point charge.

Oh man, I had all these plans to derive something super cool and be "that guy" that made future generations of physicists have to learn all about that damn spin (*eye roll*).  I'd be cursed by successive generations of everyone for making their lives harder for learning more! Glorious! But now I see I would have just been Belinfante!

Previously, I had only read that two guys:  Uhlenbeck and Goudsmit tried to actually say the electron itself is spinning! (The story goes that their advisor, Ehrenfest, poor guy who wound up committing suicide because physics was becoming too mathy and he had a major life crisis, submitted it saying that since the pair was young, they could afford a wrong caused quite a stir nonetheless).  But making the charged particle actually spin implied it was spinning too fast to make sense with the rest of physics (about 10 times faster than the fastest thing there is, light).  That article I linked to you above presents a solution without those problems; it works with lots of other things like quantum field theory.

Well, this is surely a taste of bitter physicist's medicine where you realize that nothing that you do will ever be important.  Ever.  I guess the only thing left to do is get physical exercise, talk to people, and find an inner purpose in life.  I also ought to get back to whatever Kieron wanted me to do...something involving spin, actually.  This is somehow proving karma exists, no doubt.

But I should avoid getting too into my work!  There's more lessons to be learned from old physicists than just the physics.  Good thing I skipped out on work yesterday to watch the USA win against Germany 0-1 and advance in the cup!

Tuesday, June 24, 2014

Welcome back, Professor!

Dear Diary,

Kieron came back from his epic summer quest.   We're all ecstatic!

Today we are all Vinnie Barbarino.  But we're keeping up the hard* work.  Unfortunately, this morning, I had a meeting, and then another meeting, and then another meeting with some meetings in between.  Tomorrow, I'll do some physics.  But it looks like I'm prime position to carry over some momentum from getting so much done last week that this could be a productive few days too!

Whew, it's been a bit hot in here recently.


Thursday, June 19, 2014

The Goal of Graduate School

Dear Diary,

A recent graduate, Beau Martini gave an electric group presentation today.  I'm really glad Kieron recommended him; he did really good work!  Very inspiring!

Oh man, I need to devote my full attention to the presentation and get soccer off my mind.  You see the GOOOOOOOOOOOOOOOOOOOAAALLLLLLL of this project is to score some sweet alternatives to Fourier transforms.  But if there's noise in the data, it's a problem for the method to work properly.  That's a major red card...err, flag.  At this point, things got a little bit Messi since the math is quite problematic.  But we're looking for the last gasp equalizer...

Forget it.  I'm going to check the soccer score once this is over.

Tuesday, June 17, 2014

The Case of the Disappearing Kieron

Dear Diary,

Kieron is out this week, so it's a perfect time to get caught up on all those things that I haven't had time to do between requests for editing, meetings, and everything else.  Basically, I'll have a chance to get all those things done that I'm not supposed to be working on and hope I can work fast enough to have something for Kieron when he gets back.

For example, Attila asked me some time ago to make some data.  With all this extra time, it's nearly finished!  In fact, I'm looking at a lot of little numbers on one side of the screen right now!  They're getting lower!

Oh, and the world cup is going on right now.  Very exciting!  But I need to take advantage of this week, so I'll only watch the games from the Netherlands, Argentina, and the USA.  Oh, and maybe Germany, Colombia, and Switzerland.

And perhaps England, France, and Japan.

Ok, but that's it if you also include Honduras.

Monday, June 9, 2014

How to not (!) bar hop in Montreal

Dear Diary,

While I went to sleep last night, some of the other people decided to hit up the local pub in town and, this is the best the pre-eminent physicists of our generation could come up with, ask girls if they would buy them drinks.  Careful planning went into this by looking up certain useful French phrases, and scouring The Guide to First Impressions by Franz Kafka, from which the conversation went something like:

Physicist [translated from accented French]: Could you buy me a drink?  I don't have any money.
Local:  No.
Friend of aforementioned physicist:  No, but he doesn't have any money.
Response:  [Nothing]

For the record, one response is to ask why the friend can't give the original questioner some money, but the people around here are much smarter than that.  They just start ignoring you.  No attention, no responses in English, and no money.  $mart people!

The funny thing is that the next morning when they were relating their triumphant (?) adventure, they seemed to have enjoyed getting stifled.  Good for them!  But something still doesn't add up.  After they told me their story, I started asking them for some money, but they wouldn't give me any!  They just laughed at me!  But, really, I don't have any money!

Rose:  No, really, Dr. Who doesn't have any money.

You know, I should have seen this coming.  A few days ago, one of them asked me to  buy them a drink, and I did thinking they'd pay me back!  I was a practice run! They were testing their tricks!  And I was foolish enough to let it work!

The only real winner here was one of the more suave students wore sunglasses which were a big hit!  He was wearing his sunglasses at night!  Nobody else got any attention except from some travelers from Montreal who were also having no luck getting any money from women.  It's not like the pockets of the locals are bottomless!

Word to the wise:  dress up when you go out.  Everyone else will.  If you look like a hobo in a sweatshirt and ask for money, it gives the wrong impression.  A dress shirt and sunglasses are a must.

Thursday, June 5, 2014

Not your American Summer Camp

Dear Diary,

Here at Jouvence, the main inhabitants during the week are young tween-ish or younger kids led around by their eclectic band of adult leaders.

Why just today I saw one holding a kid's hand in one hand and playing an accordion with the other while singing in French.  Some kids in front of him were sort of skip-jumping wildly, enthusiastically and singing along.  The leader was just missing a beret and a cigarette to keep it from being too French!

Another time, me  and some others were playing volleyball when a bunch of kids showed up with adults in fluffy, enormous hats and various brightly colored clothes.  They rolled in, started a fire, and sang songs.  It was all disorganized and frolicky; like they just let the kids play. Lorenzo whistled "If you're happy and you know it, clap your hands" and all the kids clapped and started singing, giggling.  So fun! It looked a lot more fun than the American camps I've been to.

Ok, back inside to listen to some more physics.

Tuesday, June 3, 2014


Dear Diary,

Ok, doing some stuff with ABINIT and mastering their loop stuff.  I'm glad the first programming language I learned was Fortran because ABINIT is based on it.  Oh my, what's this?  In the tutorial it reads:

We will use the Perdew-Burke-Ernzerhof functional, proposed in Phys. Rev. Lett. 77, 3865 (1996)

Hmm...I wonder if that's the same Burke.  I'll have to ask Kieron when I get back.  It sure does take a bit longer to run than LDA...but the numbers get slightly better.  For the bond length, that is.  LDA does better on the atomization energy.

Do not forget that the typical accuracy of LDA and GGA varies with the class of materials studied...

[Editor's note:  By slightly, we mean a few fractions of a Hartree which is a big unit.  A small increase in a big number is a big number.  Idiot.]