Strings, Rings, and Other Things

Every time I start teaching quantum mechanics in intro physics, I wind up feeling a little disappointed. To most students it's just another set of equations to memorize; they don't understand how much of a radical departure it is from everything we knew before. I suppose that's inevitable to some degree, since modern kids are raised on a diet of atoms and electrons and what seemed radical a century ago is familiar today. But I'd still like them to understand that this is something New, and Important.

So I spent entirely too much of the past week writing something akin to a live-action role playing game. In class on Friday (and continuing into at least part of this coming Monday), the students became world class scientists trying to figure out the "newly discovered" photoelectric effect. They're each a supporter of one of two competing theories of how light (classical electromagnetic waves) interacts with a metal surface to eject electrons and cause current to flow. On Friday, I welcomed them to the conference in the role of the physics department chair at the host institution:

[I stole this picture from a student's public Facebook post, by the way: thanks David T!] In their two big groups and then in six smaller lab groups, the students assembled a set of graphs illustrating their competing predictions, and then the leader of each main group presented their results to the conference.

And after that, the experimental data came in ("from the experimental conference down the hall"). Both groups got some things right, but fundamentally, everyone was wrong! So on Monday we reconvene to see if we can puzzle out the true story. I have absolutely no idea how that's going to go. I've tried to seed elements of the real (quantum!) explanation among them, and if anyone is particular clever or eager to get it right they might think to actually read the textbook. (On their own!) We'll find out! If nothing else, it was clear that they had a lot of fun with the activity, and they really were thinking hard about what their predictions should look like. I feel good about it.

In case you're curious, I'm including a glimpse of one character sheet here. I'll stick it behind a cut: ( The first page of Prof. Parma's character sheet. )

Glee-fan friends: I hear that last night's episode featured a fun cover of "Baby Got Back". I hope you liked it! It's a great parody arrangement written by Jonathan Coulton, one of my favorite singers today. You should check out his music; some suggestions to get you started are here: http://www.jonathancoulton.com/primer/listen/

For what it's worth, the Glee folks were pretty cruddy in the way they treated JoCo. They didn't give him any sort of credit on the show; in fact, they didn't even tell him they were using his work. NPR had a great writeup about it here: http://www.npr.org/blogs/monkeysee/2013/01/18/169706944/ive-heard-that-somewhere-glee-covers-baby-got-back-and-it-sounds-familiar Meanwhile, Coulton's own blog about it is here: http://www.jonathancoulton.com/2013/01/18/baby-got-back-and-glee/ As a JoCo fan, I wish that Glee had found a way to express some gratitude to him.


Oh, and a final comment: When Ace Books used a copyright loophole to print an edition of The Lord of the Rings behind Tolkien's back, Tolkien added a note about it to the next authorized edition: "This paperback edition, and no other, has been published with my consent and co-operation. Those who approve of courtesy (at least) to living authors will purchase it, and no other."

If you share that sentiment, here's a direct link to a page where you can buy JoCo's recording of the song: http://www.jonathancoulton.com/wiki/Baby_Got_Back

(And, y'know, at least Ace Books printed Tolkien's name on the cover.)

[I'm guessing that a lot of my friends here are more likely to know the JoCo side of this story than the Glee side, but I wanted a more "solid" home for these comments than Facebook.]

I saw The Hobbit a few days ago, and I enjoyed it. I started to write up some brief comments on the movie to post here, but they got a bit out of hand, so I've posted them on my Tolkien website instead. For those who are interested, have a look at my full review; comments are welcome!

[Steuard is finally catching up on old stuff he's been meaning to post here.]

A while back, a friend of mine linked to one of the comics below, and I eventually tracked down the whole series. I don't know what I would have thought of them five years ago, but given where my life is today I find them all tremendously sweet. When you have a look, it may help to remember that Francis Bacon was a philosopher, too.

Here are the first, second, third, and fourth entries in the series; I think that's the complete list.

I was thinking about color this morning (yes, I do these things), and I was struck by a disturbing thought: when did I last see violet? Not purple, which I see all the time, but actual violet. [I'm not the first person to wonder this: here's a very thorough discussion.]

Purple, as you no doubt recall, is a compound color: it's what we perceive when we see a mixture of red and blue light. But violet is a pure color: light with wavelength somewhere a little over 400nm. (Side question: anyone have a clue as to why purple and violet are perceptually similar?) So what's the problem? RGB monitors, that's what. The shortest wavelength of light produced by an RGB monitor is blue, which is probably around 460nm or so. That means that your monitor is incapable of producing a violet color. Looking at a picture of a rainbow on your computer screen is inevitably a less vibrant experience than seeing one in person.

So, fine, look at a printed photograph. Well... not so fast. I don't know how all the different types of photo printing work, but a lot of printers are RGB or CMY themselves (and I think that CMY has the same problems as RGB in this regard, or worse). I have no idea what the process is (or was) for traditional photo printing from the analog era, but I'm willing to imagine that there are photo printers today who are capable of printing with actual violet dyes. But wait: what sort of camera took the photograph? Again, I don't know how good traditional film cameras were at capturing violet, but today's digital cameras are (as far as I know) also RGB.

So: when did you last see violet? Think back: what does it look like?

This is an absolutely stunning image: the Curiosity rover spotted while descending to the Martian surface, dangling under its parachute. It took some tremendously careful calculations by the Mars Reconnaissance Orbiter team (and some good luck) to snap this shot of a fast-moving object in the few moments available (they had to aim the camera in advance, tell it when to take the shot, and hope). The Bad Astronomer gives a bit more detail. (Click the image for a larger version.)


(Image via NASA/JPL/University of Arizona )
I honestly yelped out loud with glee when this image showed up on my screen. (Good thing my office door was closed.)

I'm still in awe that this insanely complicated landing scheme worked; for once, the reality of space exploration turned out to be just as awesome as what science fiction promised us fifty years ago. I mean, heat shields and parachutes are old hat, sure, but to follow those up by setting the one-ton rover gently on the ground using a crane suspended from a hovering rocket platform? That's just crazy talk. (Here's a nice video summary, for those just catching up.) And it worked. IT WORKED. (Sorry... I seem to have something in my eye.) Now we get to find out what remarkable science we can do.

EDIT: For those who aren't following all this on their own, a couple of followups. First, it turns out that the same (large) image by the MRO also includes the heat shield that had separated from Curiosity a minute earlier, still falling toward the ground. And second, there's already a rough video of the landing as seen from a camera on the bottom of Curiosity itself. (It sounds like they'll eventually have the whole thing in high definition, too!) This just keeps getting cooler.

In thinking about The Hobbit today, I've hit a guess as to the proximate reason that Jackson decided he wanted three films. (The studio's reason is clearly "more money".) I think it may be significant that nobody has ever said a word about where Jackson planned to split the story into two films. My guess is that after watching a rough cut of most of what he's filmed, Jackson couldn't find any good place to make that split... but with a bit more work, he he could see a good way to split it in three.

My guess is that film 1 will run from the start of The Hobbit to the final escape from the Misty Mountains: an intense sequence fighting with goblins and wargs and a rescue by the eagles. Film 2 will be a lot like Jackson's The Two Towers: those on the primary quest will travel slowly toward their mountain destination until everyone but a single hobbit is locked up, while a secondary thread will split off and wind up occupying most of the movie's runtime with a single battle scene blown wildly out of proportion beyond the attention Tolkien actually gave it (the White Council driving Sauron from Dol Guldur, in this case). Film 3 will center on the escape to Lake Town and the various confrontations with Smaug, and will wrap up with the (overemphasized) Battle of Five Armies (and "too many endings" again). (All three films will pull in substantial chunks of historical or auxiliary content from the LotR appendices.)

Charged particles released after the big solar flare last week have been reaching the Earth all weekend, and there's a good chance of an impressive aurora tonight! (I probably ought to have said something yesterday...) There's a good Aurora Forecast page from the University of Alaska that will show you what to expect where. In fact, if it weren't sunny right now, their Short Term forecast map seems to imply that auroral activity would likely be happening right over Michigan (and Montana and Maine and possibly even farther south than that) and that it might even be visible on the horizon as far south as New Orleans. Who knows whether it will be anything like that tonight, but try to have a look!

The rumors were true! Both experiments at the LHC that were searching for the Higgs announced discovery-level evidence early this morning. This is a Big Deal, even if we did pretty much expect that the LHC would produce a result like this eventually. There's a lot to say (and lots of good discussions out there at various technical levels), but for a nice layman's overview I might recommend Bad Astronomy's Higgs post. The quotes near the beginning of this post by Tommaso Dorigo are good, too.

The very short version is this: a new particle has most definitely been discovered, and CERN found it by looking in all the places that one would look for the Higgs. Its properties aren't nailed down very well yet, but they appear to be broadly consistent with the properties we expect for the Standard Model Higgs. But, enticingly, there are tentative hints of some differences from that expectation, too. Further data over the next few years will (we hope) show us whether those differences are just random noise in the detection system or whether they reflect entirely new physics. (Most of us really, really hope it's the latter.)

Edit: I've seen some folks linking to a nice video explaining the Higgs from PhD Comics a couple of months ago. Also, since the topic of Comic Sans came up in my blog last week, I'm sad to see that the things I grumbled about last December were still a problem for the real announcement.

Edit2: Strassler's post lists a few more specifics in a nice, clean way.

When our college president sent out his monthly campus update, I was pleasantly surprised to see my picture: he was happy about the very successful public viewing event that another professor and I arranged for the transit of Venus on June 5. (I'm up for tenure this fall, so the recognition is good!) We got an article on the front page of the local paper that morning, and between that and a campus email we wound up sharing the event with something like 150-200 people over the course of the evening.

It was a lot of fun. We gave people three ways to view the transit. They could stand in line to look through our good telescope (with its solar filter). (That's what's pictured above, though this was just my attempt at a hasty, imperfectly-focused shot right before I had to leave. You can barely even make out the cool sunspots in my picture.) They could look at a fairly large image projected on the wall (pictured below), which wasn't as clear but allowed lots of people to look at once. And finally, they could use my Harvey Mudd solar viewing glasses (thanks, HMC!): it was just possible to make out the round black disk of Venus blocking the sun without magnification, but that was one of the coolest parts of the experience for me.

( I won't clutter up everyone's friends pages with pictures... )

That last picture shows an impromptu scale model of the inner solar system that I set up on the football field (right next to the telescopes). I put a picture of the Sun on the 25 yard line, with the right scale to match Earth right on the goal line. Venus then wound up on the 7 yard line. If you click to zoom in on this photo, you might just be able to spot the tiny picture of Earth printed there (which is also to scale, along with the Moon and the distance between them). The solar system is big, and it's something of a miracle that these tiny little planets with their differently-tilted orbits ever manage to line up enough for transits at all. In fact, I got rather excited talking about all this to the crowd: a friend took a video of me giving my last "welcome chatter" of the night, after the crowd had thinned out a lot. (The college made its own video of the event, too. But it doesn't look like anyone thought to take pictures of the long line that we had for the first hour or so.)

Finally, the fun of the event and of tracking down pictures of the sun and planets for my scale model got me interested in making a poster of the planets to put up outside our planetarium. I spent a block of time hunting around NASA websites for big chunks of a weekend and a few evenings, and assembled this:

The full-resolution PDF will print 4'x3' with a resolution of at least 120dpi (and considerably more for many objects); I'll eventually be sharing it under a Creative Commons license. I'm pretty proud of it: you can't read them on this little picture, but each planet and moon comes with some interesting fact about the object. (There are very few posters like this based on real images, and too many of those obsess over dull numerical data instead of remarkable things like Mars's seasonal dry ice caps or Triton's probable geysers of liquid nitrogen.)