It’s 9:03 am, and the propaganda informational film has just started…

9:05 – I’m here in the back row of the main auditorium, which is absolutely full. There are supposed to be two viewing rooms in building 40, the main ATLAS/CMS building, but unfortunately those don’t open until 9:30 apparently.

9:07 – eww, relativistic mass.

9:09 – bizarre low frequency sound effects. Reminds me of those supernovas in planetarium shows which always scared me as a kid.

9:10 – live feed begins.

9:13 – they will try to send beam 1 (clockwise) around, one sector at a time.

9:17 – Lyn Evans doesn’t know how long it will take, but he hopes less than 12 hours.

9:19 – Robert Aymar thanks everyone.

9:22 – It’s like a Mars landing! But we get to try again and again.

9:29 – in building 40, where the chairs are comfy.

9:34 – some beam went in! Everyone laughs when a commentator asks “did you see it???”

9:38 – beam went to point 3.

9:40 – instant replay!!!

9:42 – they’ve actually managed to go to point 5 before, so so far nothing completely new.

9:45 – “It’s not just like switching on your mobile phone.” Beam at point 5.

9:51 – “They’re very young! 30s and 40s!”

9:53 – CMS seems to be showing a trigger rate. They are now going to test the beam dump at point 6.

9:59 – LHC status page here.

10:01 – Lyn Evans tempts fate by saying everything might be done in an hour.

10:07 – Point 7. Orbit has lots of excursions between 6 and 7 so they need to fix it.

10:12 – Point 8. One more before ATLAS!

10:18 – Point 1!!!! Loud clapping in ATLAS viewing room.

10:23 – next step is full circle.

10:25 – full circle.

The two red dots in the leftmost image show successive passages of a proton pulse through a monitor at point 2.

10:34 – They’re talking with ALICE. The ATLAS logbook shows that we did indeed see signals in the liquid argon calorimeters as the beam went through.

10:42 – we have ATLAS event displays! And very ugly they are, too.

10:43 – current plan seems to be to switch to beam 2 in an hour and a quarter.

10:49 – Everyone’s gone to do other things; room is much emptier now.

10:52 – Maiani dreams of a linear collider at CERN.

10:57 – Commenter points out that cost of LHC ~ cost of Beijing olympics. But only one will tell you about dark matter.

11:25 – Will Young-Kee Kim wear pajamas??? Only videoconferencing will tell!

11:29 – so enthusiastic, the commentators are. And so soothing.

11:30 – Fermilab promo movie.

11:33 – Umm… it’s unclear if the FNAL directorate are wearing pajamas, although they’re certainly color-coordinated. They also seem to have large stickers of some kind.

11:35 – Pier Oddone brings insane US liquor licensing laws to the attention of the world.

11:37 – The DOE is proud of us! Yay!

11:41 – as is the NSF.

11:43 – in the great American tradition, many people talk.

13:05 – after an unannounced lunch break for me, time to get back to work.  Everything on the accelerator side was very impressive this morning, and now the detectors have to follow that act.  I leave you with an ATLAS event display from when the beam was stopped on the collimators just upstream of point 1:


The original incarnation of the CLEO detector first started looking at the products of e+ e collisions in 1979; the latest (and last) version, CLEO-c, recorded its last event at 8 am Eastern today – an electron and a positron bouncing off each other. Along the way, 450 papers have been published on CLEO data. We had a little celebration in the counting room as the last run, 234607, ended:

Last CLEO run

There’s still a lot of work to do – we need to decommission CLEO and reconstruct and analyze the last data!

Particle Physics 2.0?

April 3, 2007

Elsewhere, Tommaso Dorigo makes a plea for particle physics experiments to enter the (free) blogging world. I find the argument intriguing but problematic.

A couple of issues are raised. One is whether the data should be made available to the public (in ASCII four-vectors or whatever); after all the taxpayers fund us, shouldn’t they get their money’s worth? I certainly agree that this is desirable, although extremely complicated. Our experimental architectures have not been designed to enable this in a simple manner (it can take literally months for a new collaboration member to learn to access data!), but if this was specified as a requirement from the beginning, as I believe it is for NASA projects, it could probably be done at the expense of a lot of physicist-years. However what is in question is not the data, but the analyses that follow, and even projects that release their data allow that what you extract from the data is your work.

Another is how collaborations communicate their results to a wider audience. Communication can almost always be better, and it’s a fair point that analysis web pages rarely go much beyond a brief technical summary and some plots. At one point, I know CDF was trying to post “plain English” summaries of physics results on the web, though for some reason all the links seem broken now. Regrettably but understandably, in the pressure to get results approved, papers written, and talks put together, the plain English version is seen as a low priority. Blogging might improve this.

[Aside: actually, we tend to communicate directly to specialists, ignoring even other particle physicists. We don’t like to admit it, but we, too, get lost and bored very easily by work we don’t immediately grasp. Try keeping an average Tevatron physicist’s attention through a 30 minute talk about measuring angular distributions in χc radiative decays. I dare you.]

Finally, should experiments somehow embrace freer discussion of the data they collect and give up their roles as “sole authoritative commenters of the results they produce”? Are they? The speed of rumor is extremely high in the theoretical community, and (as an example) theorists seem more openly dismissive of the LSND results (because they don’t fit nicely into models) than experimentalists are (they can’t find anything obviously wrong with the experiment). It’s hard to imagine anyone being more authoritative than those who produced a result.

Oh, you mean should experimentalists be free to go “off message,” as they would say? There’s a tricky one. Why shouldn’t a collaboration micromanage how an important result is presented? If I spend a couple of years working on a result, and someone completely unrelated to it is the one who gets to reveal the numbers at a ski resort or be quoted in a popular publication, is it silly to want the right to sign off on what they say? To change this would, I believe, require a fundamental rethink of what a “collaboration” is. In the current model, you are either “in,” in which case you’re generally expected to speak for the collaboration when on record (because you have privileged access to the details and your name is on the papers), or you’re “out,” where you can say whatever you like at the expense of having your opinion discounted. If we atomize into having authors be solely responsible for their analyses, then we will all be able to say what we like, and will lose the ability to report on “our results.”

Incidentally, I’m not sure how an “experiment-approved blog” would address the last point. I think the sticking point is “experiment-approved,” not “blog.” Imagine approving blog entries at physics group meetings, spending hours discussing word choices …

Collaboration Meeting!

July 17, 2006

Experimental particle physics is a very social endeavor. We love to see each other so much that we schedule lots of meetings, from small person-to-person get-togethers to huge conferences. It’s just so much fun to sit in windowless rooms!

One common form of assembly is the Collaboration Meeting. Every collaboration has a Meeting. It occurs with some frequency, which is set by the difficulty of getting everyone together in the same place at once. Mega-international collaborations have them relatively infrequently, sometimes in pretty places on different continents from the actual experiment.

The Collaboration Meeting, as a platonic form, is a forum where all the people involved in an experiment get together, catch up with the latest status of everything, plan for the future, and have a jolly good time too. Papers are approved, votes are taken, decisions of far-reaching import are made. The Collaboration is, for a shining instant, realized as a single entity. Needless to say it’s usually less exciting.

CLEOns, being a gregarious bunch, want to have collaboration meetings all the time, sometimes twice in one month. Where other experiments may have three a year, we had eleven in 2005. Since many of us are on-site here in Ithaca, and most of the remainder are in the northeast or midwest, it’s relatively easy for lots of us to come and take part in the excitement. Our meetings are so frequent, in fact, that the physics groups (e.g. bottomonium or hadronic D decays) meet on the same schedule to review the progress of analyses; we don’t hold with this weekly physics meeting nonsense that CDF engages in — once a month’s good enough.

A frequent CLEO meeting scenario goes like this. You are a poor grad student/postdoc, working hard on your analysis, but distracted as always by other responsibilities. A few months/weeks before a meeting, someone (your advisor/the Analysis Coordinator/a random faculty member from another institution) starts dropping broad hints/threats that it would be really nice if, you know, you could have some numbers ready for a conference two months from now, which means you have to have them approved for public release during the next meeting.

So you work really hard and succeed/fail in getting everything ready. If the first, you give a plenary talk (in principle to the whole collaboration) on your work, where you will promptly be asked lots of questions which you may or may not be prepared to answer. The questions need not actually relate to your work, in which case members of the audience will proceed to have irrelevant arguments while you stand in front of everybody, hiding your distress, wishing you were eating one of those nice donuts they provide in the mornings instead. If you didn’t quite make it to plenary talk level, you go through the same thing, except it’s now a parallel-session physics group talk instead. This will all most likely happen on a Friday.

On Saturday, you come in early in the morning and sit in a large room on the 7th floor of a different building. The power outlets are pretty much all in the back of the room. A continuous strip of tables is set up there, in front of the windows; a long row of people sit here, their backs to the outside, facing the speakers but looking intently at their laptop monitors the entire morning. You will listen to talks on the status of the accelerator, detector, and software (useful) and then be asked to vote on papers you haven’t read, didn’t know existed, but have your name on anyway (er…) Then there will be a lunch featuring ice cream sandwiches, in all probability.

On the whole, collaboration meetings are fun if you’re not presenting anything. If you are, they can be stressful deadlines, just another rung in the infinite ladder of similar-yet-not-identical talks one seems to always be giving on the same topic. But, when they’re over, you get to pay attention to other things again, like blogs.

I’m a bit of a type afficionado. Not a very good one, and certainly without the time to get really into the business; but I know my Janson from my Garamond, my Bookman from my Bodoni, and as they say, I know what I like. Even for physicists, fonts are important. Here follow some ramblings…


There are two classes of high-energy physicists in this regard: those who write talks in Powerpoint or similar programs, and those who write talks in (La)TeX. (Disclaimer: I do my talks using the LaTeX Beamer class, in Computer Modern Sans, sometimes with Euler for math.) The latter are a small minority, and I suspect are considered certifiable by the former. The LaTeX users pretty much restrict themselves to Computer Modern (Regular or Sans), though Helvetica and the like have been seen from time to time.

The offenses against typography tend to come from the Powerpoint folk. I must admit that some people do great things with the tool. B.L.’s Futura-themed talks are spectacular, and J.N. and students have an inspiring commitment to Gill Sans. There’s nothing wrong, exactly, with Arial or Times New Roman in presentations, although Times’s serifs get in the way, and the insistent overuse of Arial these days makes Univers seem dangerously radical. R.B. uses Textile throughout every talk, giving them the impression of being entirely in bold italics — this counts as a minor infraction.

But no, the evil of which I speak is Comic Sans:

Comic Sans sample

a font supposedly inspired by comic books and which is regarded as so horrific by so many there is a society dedicated to its extermination, where its use is described as “analogous to showing up for a black tie event in a clown costume.” If nothing else, that bent middle stem of the “m” should set anyone’s teeth on edge. I can only hope that the otherwise savvy people who use it frequently are intentionally trying to create an undertone of silliness. (Sure, it’s nonthreatening and legible. So is Tahoma, which doesn’t look like a kindergartener was tracing BIG letters.)

The Horror of Papyrus

What really gets my goat these days is the overuse of Papyrus (especially in movie promotion). I’m sure you’ve seen it around:

Papyrus sample

It’s not actually a bad font, but it is so distinctive that any use echoes all previous ones. This is a typeface whose main role is to put the reader in mind of something, and that something is exotic and non-Western (and wholesome). Nobody would use it for a film about the Scottish fishing industry or mobsters in Japan, but morality tales involving animals on African grasslands or isolated Buddhist monks can expect to get the full fat “y” treatment. The use of Papyrus is usually transparently manipulative, extremely cloying by your fifth exposure, and can’t even claim to be original.

And a Final Note

Speaking of manipulative fonts, there’s a booming business in typefaces intended to suggest the good life. Things like Trajan can be seen easily on any sign advertising Olde Brooke Towne-type subdivision or luxury goods store. But now, Orange Italic have prepared all three fonts you will ever need to sell a $1500 handbag or a McMansion: the Luxury line.