Archive for Math/Physics

Colliding Particles documentary update

Colliding Particles, the documentary that I have mentioned previously, has come out with their fifth episode, “Collidonomics”.

The documentary follows a few ATLAS physicists, doing a very nice job rendering the realities of the occupation. This episode begins with a funding review in the UK. We have just passed through the season for similar reviews in the US, where funding comes via the Department of Energy and to a lesser extent the National Science Foundation.

The DOE does a site visit every year; professors, post-docs, and some students give presentations outlining the progress of the experiment, their recent work, and what is planned for the coming year. I did a short presentation on my project for which there were some interesting times: my train hit a car on my trip back to Ann Arbor, the speakers before me ran long and squeezed my 10 minute slot to just a smidge under 0 minutes, and then both the wireless keyboard and mouse controlling the slides ran out of battery power simultaneously.

This episode of Colliding Particles also went along to the Les Houches workshop where can enjoy the Alps and get the classic scenes of physicists chatting over coffee. There certainly is great progress made in these cafeteria chats, but to someone who has followed an inordinate amount of LHC media coverage it often feels like physicists and the journalists that love them have few limits to the praise they’ll heap on the CERN Restaurant and it’s powers to birth theory and discovery. Office conversations, too, are possible (though crowding in the building 40 offices along with the openness of the remaining workspace pushes conversations away somewhat out of politeness). Also, I can’t say that I have been party to a lot of cafeteria conversations where people were just throwing around crazy ideas, most of the time you are merely following through on a topic that was just discussed in a meeting. The cafeteria is just the incubator, not the whole chicken.

The remainder of the episode is about the graduate student making a presentation in the Higgs working group. In these huge experiments the collaborations have to break up into working groups, each covering a broad physics area or an aspect of the detector operation. Roughly, presentations to a working group fall into one of three major categories,

  1. An update on the status of an analysis or study,
  2. Describing a technical issue that needs to be considered by the group, or
  3. Introducing a new technique to be blessed by the group.

In this case it is the third type.

In the end, if you want any of your work in the experiment published, you need to have all the members of the collaboration agree to your methods and results. The process of outlining your plans and progress is best started early, especially if you plan to employ an innovative technique (something everyone should be doing in some way). Usually results are discussed with an adviser or at a small subgroup meeting, until the results are refined; then a presentation is made to the relevant working group. As they say in the video, this is the point at which you most commonly run into someone who takes issue with what you’ve done. Usually this is because your work seems to improve on something they are invested in, and often their argument is that your results are not comparable to theirs. But, for the most part the comments and questions you get in these meetings are very helpful, and hopefully with a little extra work you can address the quibbles your collaborators have. It looks like this presentation goes just fine: with a few people almost nodding off and a couple basic questions near the end it’s very typical.


Mandelbrot Set

Chalkboard animation in fractional dimensions: a music video for Jonathan Coulton‘s song “Mandelbrot Set” by Pisut Wisessing

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More of CERN in the news

new_yorker_cern_icon.jpg…but first a word from our sponsor: HP references CERN in an advertisement.

With the LHC (hopefully) ready to turn on in the very new future higher energy physics (HEP) is in the news plenty. We begin with the most far reaching: the New York Time (Feb 9) discusses the International Linear Collider (ILC). HEP is in the awkward position these days of requiring apparatus that are so huge and complex that they are 10 or 20 years in the planning. The ILC is the sort of machine that will be difficult to motivate without very strong evidence of new physics at the LHC. But of course the LHC hasn’t even started running. So where’s the motivation? For the moment, in our hopes and dreams mostly.

Three months later (May 15, to be precise) the NY Times follows with an article about the LHC.  And nearly that same day (May 14) the New Yorker publishes a long article on the LHC. Of all these I think the New Yorker article is my favorite. The author seems just a bit more comfortable employing some technical terms while mercifully dancing around some topics that can be hairy to explain,

Arkani-Hamed spent nearly two hours trying to take me through the details of just one of these—the so-called “hierarchy problem.” In the process, he consumed four or five or six cups of espresso—even this I lost track of.

I also liked this bit,

The L.H.C. is a kind of Babel built underground. Dozens of countries have manufactured its components, and dozens more have lent manpower and expertise…. When I ate in CERN’s lunchroom, I heard people speaking English, French, German, and Italian, as well as several languages that I couldn’t identify. The place was so crowded that it took me five minutes to pay for a cup of coffee, proving the elemental truth that man can build a superconducting collider but not a functional cafeteria.

Despite a redesign, which does open up deperately needed space, the cafeteria still has problems.  The natural places to line up still end up getting in the way of everyone else.  Also, the silverware is at the entrance, when it should logically be at the exit after you know what you are going to eat (I hate to commit to a knife that I may never use).  Of course they did put napkins at the exit, but right before you pay, somehow insuring that I always forget to get one.

Finally, there was an NPR story on the the LHC back in April.  (Yes, another old article, but I doubt you have come to expect too much promptness from me.)  I missed the live version, but the NPR archive is a wonderful thing (they throw in some bonus web content too). Unlike a lot of science stories it left me with a great big grin.  Though the focus is on the enormity of it all and the quickly approaching startup, I thought they did a nice job of representing the science, it’s challenges and goals.  David Kestenbaum approaches the topic with just the right mix of respect and childish glee.

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Day to Day Communications at CERN

I’m at CERN right now and I met up with Pascale and Giulia for a walk around Geneva. Giulia told me about an awesome video, a parody of another CERN video from back in the day. My favorite part is when they visit the professors lab at the end.

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Enjoy, and also check out the original.



This is mega cool: The Periodic Table of Visualization Methods (found via BoingBoing). It shows many different ways of visualizing data from Tukey box plots to Infomurals. The very nice examples pop up as you roll over the table. Oh, beautiful informational graphics, why do I love you so? If you love graphics in all their glorious permuations as much as I do, you need to run to your nearest book lending/selling establishment and check out Eduard Tufte’s work. I thought I owned two of his three most significant books, but I recently discovered that he has produced a fourth one, and now I’m really behind!

Log Animals page from Tufte book

By the way, on his web site Tufte lays some minor smack down on the iPhone for, of all things, the way it displays the time (scroll nearly to the bottom). The man doesn’t compromise when it comes to comas versus colons and I like that.

Speaking of Tufte, he was mentioned in passing in a course I’m taking this semester, Networks: Theory and Application. It’s not too surprising that his work came up considering how integral issues of visualization are to the study of networks. The course looks like it will be a lot of fun. It may not have much direct relevance to my research, but I’m excited about the material and the field seems to be a really popular one these days. The topic of networks is so hot it’s right up in everyone’s face(book) these days. The professor for my class even won a vote for Wired Sexy Geek of 2006, and I think the geek vote is just as much about the sexiness of the work as a pretty face. This brings me to the last juicy link of the day, for our first assignment in the Networks course we had to peruse VisualComplexity, which is a jolly good time. Check it out!


ATLAS on BoingBoing

ATLAS cavern, C-side, 7 Jan 2007

My experiment, ATLAS, got a mention on BoingBoing recently. But, what they mention, the assembly and testing of the barrel torroid magnets is old news. The cavern is already a lot more crowded. You can keep up to date with the ATLAS web camera. On one end of the barrel you can see the scaffolding within the torroid which gives access to the muon chambers nestled throughout barrel toroid and the inner systems that are partially installed. The other end is covered by one layer of the muon endcaps, the thin gap chambers. One of the detector installation cameras is trained on the first few sectors of the endcap drift chambers, the ones I worked on, which are being assemled into a full, five-story high wheel. The sectors (pie slices) are assembled into “the big wheel” against the wall on the large blue hub which is the most prominent element of the view. Later, as a full unit, the wheel will move up against the end of the barrel. More details are on the ATLAS public page, including a very nice video.


It’s Math, not Physics

Jackson Pollock paintingYears ago, when I heard about Richard P. Taylor’s work quantifying the qualities of Jackson Pollock’s paintings using fractal concepts I was vaguely amused. Supposedly he could discriminate Pollock’s work from that of other drip painters purely algorithmically. It seemed suspicious, but within the realm of plausibilty, and considering he convinced Nature to publish his work I was willing to go along with the idea. During idle chit-chat I’m sure I pulled the topic out of my trivia hat from time to time in the intervening years. Now it seems the reliablity of the fractal method is in question, and the issue is pressing: someone claims he holds a number of undiscovered Pollock paintings that could could be worth millions if authentic. Taylor analysed the works and determined that they show significant differences from know Pollocks. But, a new article in Nature claims Taylor’s work was flawed. So, are the dribbles original or derivative?

I don’t really care. Mostly what I care about is the last word in the headline, “The Case of Pollock’s Fractals Focuses on Physics.” Physics? To an unreasonable extent this pisses me off. What about this analysis is physics? Just because physicists did the work doesn’t make it physics. The mathematics that is used may also have physical motivations and applications, but it still is distinctly mathematics and nothing more. I’m sure my bitterness stems from the fact that physicists seem to get all the glory in the press. And, even though I am now one of those glorious physicists, I will always have much empathy for mathematics. With popular media equating mathematics with the mentally disturbed, will science’s crazy uncle ever get the regard that he deserves?

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Mevin Schwartz

Melvin Schwartz next to a spark chamberBNL and The N. Y. Times report that Melvin Schwartz has died at the age of 73. I was reading about his work on a poster at BNL just last week (he is one of quite a few nobel laureates who have worked at BNL). Schwartz is the co-discoverer of the muon neutrino, a particle discribed as “wispy” by the N. Y. Times. More recently he had a managment role at BNL during the construction of the Relativistic Heavy Ion Collider (RHIC), which is the large collider dominating the campus of BNL now.


Return from Fermilab

HCP Summer School logoA week ago Friday I returned from 10 days at Fermilab for the HCP Summer School. I had some misgivings before my departure. Being stranded in the distant outskirts of Chicago for lectures consuming 11 hour days sounded potentially very painful. To my relief it turns out the lectures were broken up with significant coffee breaks and epic lunches. In addition, the coffee break snacks were usually quite plentiful and tasty (all except the fried cheesecake squares, ick!).  Even on Saturday we had a nearly full day of lectures and discussion, but the beautiful day ended with a barbeque.  Monica arrived to spend the next day and a half with me at the barbeque and then in Chicago on our Sunday off.  In Chicago Monica and I visited the Shedd Aquarium and did some walking along the waterfront and Michigan Avenue. I took many photos and so Chicago gets its own gallery.  All the days we spent significant time outside, the two barbeques, the Sunday in Chicago, and the tours around Fermilab, all had great weather.

Oh, and the physics was very interesting. We didn’t actually have continuous lectures. Usually twice each day we met for smaller discussion sections (the group of 150 split into four groups) that were focused on answering questions. Sometimes these were very informative.  I really felt the influence of my analysis experience and the particle physics class last semester; there was almost no time when I felt totally lost, and yet I learned a lot. (They ended up getting so much interest in the school that they had to be selective and I hear having some high energy physics experience was the major criterion for acceptance.)  I think the only time when I certainly got a little lost was when were were talking with Chris Hill, the head of the theory department at Fermilab, over dinner; but still that discussion was very interesting.  Most of the lecturers were very good speakers and I expect I will refer back to their slides many times in the future.  All the lecturers were taped and are supposed to be available from the daily program in the next week or so.
Fermilab turned out to be quite a nice place, the main building is certainly impressive (much more so than anything at CERN) and the natural features are pleasant.  My one complaint, after eating lunch and dinner there for nine nearly consecutive days, is the food.  It was never as good as what you find at CERN, and sometimes pretty miserable.  A notable exception to the dinner deficiencies was the final night. I got the impression it was mostly home cooked. There was a tomato and buffalo mozzarella dish made from tomatoes grown in the user’s garden right in Fermilab (but, no word on whether the Fermilab “buffalo” (i.e. bison) were involved in the mozzarella).  Also, I ended up with a lively hoge-poe of people at my table; there was a pair of Italians, Chinese, and Bangladeshies in addition to me, the ugly American, though none of these “pairs” came together. We also came from many different experiments and the discussion in and out of physics was fun.  I observed many other tables indulging in the merrimaking of the open bar so I expect good times were had by all that night.


Fermilab Tours

We spent over three hours before lunch today touring seven sites around Fermilab. They included the DO and CDF assembly halls and control rooms, as well as a few random places like

  • the helium compressor station, it takes 5 megawatts of power to keep the liquid helium cooling the superconducting ring a few degrees above absolute zero,
  • the linear accelerators that do the initial acceleration of the protons
  • the accelerator control room
  • the views from the 15th floor of the main (and by far the highest) building, Wilson Hall,
  • and the silicon pixel detector assembly building, with millions of channels these are used for exteremely precise tracking of particles very close to the interaction point.

I uploaded many photos to my Fermilab folder in the gallery.

Setting up for neutron therapy at FermilabIt was interesting to pass the neutron therapy room along the linear accelerator. You walk down a hallway with gauges, big red lights, waveguides and a generally very industrial feel and all of a sudden you come to people wearing scrubs in a controll room and, just past them, a little waiting room. They use the accelerated helium ions to produce fast neutrons that are collimated and pointed very carefully at a patient’s tumor. While we walked by we could hear the physician speaking to patient on an intercom, telling them that the treatment was almost done. You don’t actually see the patient; they are strapped in very carefully and the small room is lowered to the level of the beam underground. I’d imagine it is a very scary process for the patient (though the patients have probably been through many other types of radiation treatments by this point, neutrons are mainly used on very resistant tumors.)

I’m really enjoying the summer school here. I’m learing a lot and the 9am-8pm days are not nearly as bad as I worried they might be. We get breaks between every lecture and lunch is especially long. As long as you show up rested you really don’t get worn out too much. Wilson Hall is very dramatic and so far I am enjoying hanging out there. The one clear deficency (compared to CERN) is the food and beverage. The coffee is standard American fare, and today I had some terribly dry turkey for dinner.


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