Noticing something very bad is about to happen when your child sits down on a raised plaque at the base of a tree, and you only have a split second to give warning, your brain comes up with the following sentence: “Honey - Julia shouldn’t sit on that inclined plane because it is covered in poop!”

On the drive from Marseille to Genova I asked the 3 others in the car if they used Instant Messaging (IM). I was the oldest in the car (getting close to 42!) and the rest ranged from mid thirties to late thirties. All are like me in that they have permanent positions. All have students, though I was the only professor - the rest were at labs around France.

How many people used IM for work? None other than me. Who used IM at all? None, other than me. On the way back I was in a car with graduate students - so mid to early twenties - but I totally forgot to ask them. However, since I rode with their advisors on the way out there I can be pretty safe in guessing they don’t use IM for conversations about physics with their advisors.

So, I have a bunch of questions. Do people use it mainly for social interactions? Or am I just in a bubble and it turns out that lots and lots of people use it for work and I just move in the wrong circles?

It was the day, not much more than two decades ago, that HEP lead the world in computing hardware and (to a lesser extent) software. We had to push it forward - the power and flexibility was just not there. I think if you look at the way we operate now - it looks very similar to how it looked back in the ’60’s. Command line. Simple text editors (vi and emacs are BIG). Batch jobs. The older set are only just getting off pine - a text/terminal mail program (moving mostly to the FireFox mail mail reader, and some to web clients).

Is there something holding us back? Or are we as a field voting with our feet: these things don’t help us get new physics results out? Perhaps we usually are in labs where you can run from one office to another and so email is good enough? IM interrupts our workflow and so we don’t want to let it in? What about all those Web 2.0 tools out there? Much of that is based on social networks and so if a lot of physicists don’t get on there, then it doesn’t really help. Are we slowly building critical mass? Or does it just not excite us yet?

Comments?

Just to make sure I stay ahead of the curve, I’m trying out friend feed - think of it as a way to aggregate all of your online activities… Of course, I don’t have many online activities.

Graduate student and advisor bonding over Joss Whedon and Buffy.

Having to go from 8pm to the next morning at 9:30am without a portable. Didn’t get to write a talk I was asked at the last minute to talk about and also got a full 8 hours of sleep. Not done that in months.

A less scary moment was getting lost on the streets of Genova, Italy. This city is packed to the gills with buildings - it is impossible to get a lay-of-the-land unless you are on the side of a hill.

I have pictures, as usual. Along with some from a pretty stunning hike.

I noticed in a Fermilab Today issue (the May 3rd issue) that Fred Ullrich retired. He ran Visual Media Services forever (well, as long as I can remember). I’ve interacted with him on and off for years. Sometimes begging him to prepare a poster for a conference that I’d waited until the last minute to finish off. I wanted to send him a congrats email. But I can’t find his email address!

So, as usual, I’m going to take this one little anecdote and extrapolate it way beyond reasonable limits (this is a blog, after all). The normal place to look for this sort of thing is the Fermilab white pages - an online directory. But the problem is Fermilab has taken computer and employee security to the level that pretty much the day you leave Fermilab all trace of you ever existing is removed from their databases. I realize this is how all of corporate America (and perhaps the rest of the world) works, but the problem is Fermilab feels like a “home” to me - and so this seems like fairly harsh treatment. Not something you’d do to your friend - especially as they are leaving on good terms. Queue the refrain “Ah, it was better in the old days…”

Bummer. At any rate - Fred - thanks for all your help over the years, and have fun starting the second half of your life!

Visual Media Service has a great collection of pictures taken over the years at Fermilab (ha! the page still says to contact Fred — he isn’t gone yet!!). Well worth looking through!

Being an American, I’m a capitalist. Thus, I’m greatly in favor of competition. And there is a big competition coming down the pike: ATLAS vs. CMS. Both are going to be racing to find the not only the big discoveries but also to be the first to see a Z boson, or the first to see a top pair production. In the long run I think this competition will be healthy - it will make sure results come out in a timely fashion and keep the two experiments on their toes. It is most embarrassing, after all, when your competitor points out a big mistake you’ve made!!

A bunch of us were discussing this over lunch the other day at the ATLAS Genova b-tagging workshop. One person was very against the idea of the competition, pointing to the damage it had done at CDF and D0. This surprised me; I’d always thought the competition there was pretty healthy. No, he said, from the outside he sees lots of name-calling and trashing of each other’s results.

Yuck. I hope there are very few people doing that. I can understand where the feeling comes from- you work for months or years only to be beat in the last few weeks. The science is intensity personal. Still…

This lead to us trying to sort out what was good and what was bad about competition. The title of this post was the tag line we came up with.

N.B. Not all American’s are capitalists!

I’ve mentioned before that I think multicore computing is going to hit HEP hard. The basic problem is that we run all of our jobs in an embarrassingly parallel way. If the machine has 8 cores on it, then we run 8 reconstruction jobs. There is nothing wrong with this on the surface, and, indeed, performance tests indicate that so far we observe an almost linear speed increase as a function of the number of cores.

The problem, I fear, is getting data on and off the chip with the many cores. For code to run fast it must be well fed with CPU instructions and the data it is processing. Memory and the CPU have only so much bandwidth. The HEP way of running means that all the various cores are working on very different things - different data, different code - which means on-chip cache hits will be low - requiring more data from outside the chip.

At some point this has to start to impact performance. We’ll see that when we start getting linear increases in performance.

Ars had a nice article a day or so ago on this issue when discussing the various processors and their multi-core capabilities. The study they reference looks specifically at the memory bandwidth. IBM’s cell processor did the best - this is the chip used in the PS3 gaming console. It was specifically designed for high memory bandwidth. Intel’s architectures didn’t do nearly as well, however.

I also found it in interesting that before they were able to test the memory bandwidth they had to deal with some other bottlenecks in the Intel chips. Specifically, the Translation Lookaside Buffer (TLB) (see section 4.1 of the paper for a detailed discussion). Basically, every time the CPU goes to memory it must translate the requested memory address into a physics memory address. To speed up this process, the CPU maintains a cache of these translations. If you hit the cache your memory access proceeds at a very quick speed. If you don’t, then things grind to a halt while the CPU calculates the translation. If you are accessing data spread over a large area of memory you are bound to constantly be overflowing the the TLB cache. This is interesting because it strongly resonates with one of the presentations on optimizing CMS code at CHEP. Specifically, their memory allocation and deallocation (see page 18 of the talk). This means the CPU is constantly jumping around from whatever code it is working on, to the alloc/dealloc, to scanning memory for free blocks - all these operations use up slots in the TLB without actually “getting work done”.

Fortunately, in the Ars article, they mention that the CPU manufactures, like Intel, are aware of this, and the next generation of chips will have much larger TLB’s - which should help with this issue. It is always the next generation, isn’t it?

I wonder if we in HEP will ever hit this memory bandwidth bottleneck? Perhaps when we have 8 cores on a chip (when is that predicted to happen? Next year!? :-)). Getting around the bottleneck will require some major work in how we write our code: it is all inherently single-threaded.

BTW, the point of this study was to optimize a physics simulation — a magnetohydrodynamic system. Physics is everywhere!

Congratulations to everyone at D0 and the Fermilab accelerator division — D0 has been sent 4 fb-1 as of April 30!! That is a lot of data! And years of work!

It will be a while before you see that in an analysis however. First of all, of the 4 fb-1, only about 3.5 fb-1 were written to tape. The rest is lost forever. Where did it go? Well, perhaps our detector was broken for some short amount of time. We do our best to make sure that doesn’t happen of course, but a machine like this does break (my name is no more than a few of those minutes for Level 3/DAQ problems!) We generally run our triggers with a small fraction of dead-time — time where we aren’t accepting new events even if they are coming in - if we were to run with zero dead-time we’d not be able to do nearly the physics program we do [if you want more details, let me know].

The second issue is time. It takes time to understand our data - a while to do something as sophisticated as a Higgs search. Parts of the detector are turned off, which affect efficiencies and systematic errors. The events we trigger on are changed as we try to optimize our data for the higher instantaneous luminosity the Tevatron delivers. On top of that, of course, is the continuous effort to improve our analysis technique’s power. All these changes must be carefully studied to see how they impact each analysis. And once that is done, only then can the data be shown externally. This takes quite some time. The more sensitive the analysis, the more carefully the data must be studied.

So, fantastic for us at D0 (and CDF) for reaching 4 fb-1 delivered. Thanks to the Fermilab accelerator division for doing this despite the trying times. Everyone else: sorry, you’ll have to hold your horses a short while before we show the results of this data!

Or at least your career?

I stumbled on this article while trolling the net. It is a bit sensationalist, but the message is that people who work from home always don’t advance as quickly as people who come into the office.

This is relevant to me and experimental particle physics because we are a truley global “company” - with small groups littered around the world. Most groups are probably less than 20 people in size - many are less than 10. We are effectively all telecommuting on this large LHC experiment. Many of us, including myself, have always thought that we need to maintain a presence at CERN (this is based on my experience at Fermilab).

Clearly not everyone can live there full time. I have to teach back in Seattle, for example. I use the standard tools to keep in touch: video conferencing, instant messaging, email, Skype, etc. I’ve never felt it was as effective as being there, however. Indeed, this is one of the reasons behind the sabbatical - go somewhere else, learn something new, and bring it back to the university - thereby enriching the local research program. Besides, who wouldn’t want to go to a lab where the world’s experts all congregate to work on a particular set of problems? What better place to learn and to push research forward?!

I have no idea how much these two are connected - telecommuters not being as successful and remote HEP research — but I suspect there are parallels.

By the way - I find it very hard to interpret the cause and effect relationship in cases like this — there is so much sociology involved. For example, the boss doesn’t see you so doesn’t think you are getting as much work done - which may or may not be true. Or perhaps people who work from home tend in the first place not to be as ambitious as those that don’t (I have no idea). I know that I like coming into the office - being able to walk down the hall and ask questions makes me feel, if not be, must more effective. Not sure how the others that I’m asking the question feel!

Note: Written while waiting for ATLAS code to compile. Yawn!!

This town takes May1’s seriously. It is dead. Really dead. Everything is shuttered up. I hope we have enough food for dinner this evening because it is looking like none of the usual grocery stores are even open. This is the sort of holiday that when you ask, say a bus driver, “Is the bus schedule the same everyday?” They respond “Every single day - even May 1st!”. In North America you’d say “Every single day - even Christmas!”

This is a picture of a Lilly of the Valley. People give this to each other for May 1st.

Whatever the reason, this break is definitely nicer then working on ATLAS’s transient/persistent class separation (I’ll try to say something about that later, after I’ve actually accomplished something)!

Update: Pictures from the big parade today. This parade was really about unions and workers. They take this way more serious then we do in the USA. Some of the literature handed out was quite something - this is one example of an anti-capitalist party flyer. The hammer and sickle on a red background were common themes in the flags in the parade as well.

A few weeks ago my Dad visited me here in Marseille and we took a trip along the coast to Nice. We went the slow road - a long the coast - right a long the coast. At one point we got caught in the traffic jam that is St. Tropez. St. Tropez is a playground - made famous by Brigitte Bardot.

The harbor was packed with boats that were… well excessive. Most of them were large motor boats, but there were plenty of sailboats.

However — it was cool to see that it was a sailboat that took the “excess” grand slam gold metal title. That is the picture you see here. The thing is completely computer controlled too. In fair weather I wonder if you could sail it with one person? We also joked that it probably made sail “snapping” and luffing sounds so the captain could hear what was going on — being so far away from the actual sail!

And how deep does the keel go!?!?

I’ve got a few other excessive pictures, including a panorama that shows exactly how out of hand it was in that small port.

This weekend, walking down the main drag in Marseille to the old port, I was surprised multiple times to hear conversations in English going on around me.

Summer is coming, and along with it tourists. When I was here first in 2005 it wasn’t so back. Just a few sitting in the bars along the old port. But now lots of people show up - both French and non-French. The town is really changing.

Summer is wonderful in Marseille. Warm, with enough wind to keep you from suffocating, and always sunny. Only one problem. At the end of summer it will be time for Paula, Julia, and I to return to Seattle. And teaching.

UW is a big place. And the computing folks there manage a lot of systems. Mail, of course. Our group’s computer guy knows a person involved in C&C’s mail operations and discovered that:

• 95% of all mail that arrives at UW is spam
• The record of the “sender not found” bounce messages into one account (like the ones that were causing me problems the other day) is 40,000!!! So, my problems are minor.

40,000!!! It is no wonder everyone is switching over to instant messaging.

An email just went by on a public mailing list that contained the following gem:

I have many users who have no compiler, as they are physicists and have no use for C++.

I forget that in HEP we could not do physics without C++!

I was reading an internal note today and stumbled on this great quote:

The success of the standard model (SM) has been quite unexpected, given its shortcomings. The number of free parameters ranging many orders of magnitude, absence of Dark Matter candidates, the hierarchy problem, lack of gauge coupling unification, and no path to incorporate gravity naturally lead to the belief that the SM is but a low-energy approximation of some more general and aesthetically pleasing theory. Yet despite all e orts no significant deviations from the SM predictions have been found to date.

The way that starts is priceless!

This month’s Symmetry Magazine has a feature on physics rock and blues bands. Ironically, I was at CERN last week for the ATLAS week and the Canettes played (check out their home page, as of this posting they are using one of my pictures there). I’ve seen them twice now, and they are a lot of fun. And they can pack a pretty large bar too!

P.S. One of their members runs the whole CERN computing department. Another member runs the ATLAS secretariat - which basically means the whole experiment.

The LHC hasn’t delivered its first collisions yet. ATLAS and CMS haven’t taken collider data yet. But we already have to plan for the next steps. There was a recent kickoff event at CERN for people working on the upgrade to the LHC - the so-called SLHC (Super Large Hadron Collider).

That picture above is a simulation of what the CMS tracker would look like at a luminosity of 10^35 - that is 4 orders of magnitude greater than what we expect to be running at by the middle of 2009. Being able to reconstruct that many particles is going to require both experiments to replace their tracking detectors with more robust and more accurate detectors. This takes years and years to prepare for - the R&D for much of the replacement is already well underway. They are talking about installing these new detectors in 2013 - 5 years from now.

The accelerator talk is also fascinating — but my favorite talk was from MLM who was summarizing some of the physics possibilities of the SLHC:

While there is no guarantee that any deviation from the Standard Model will be found, the existence of physics beyond the Standard Model will demand and fully justify these studies: we’ll be measuring the properties, however trivial, of something which we know exists, as opposed to blindly looking for “we don’t know what” as we are unfortunately doing today!

Worth a look if you are curious about the next step!

I have complained about the Margin Lady before:

The Margin Lady occupies a special place in the physics-thesis-writing ethos. … You knew the Margin Lady was on the horizon so you used a document template that was sure to satisfy her: figures just so, page number is the right spot, margins just perfect. It just doesn’t matter. No matter how perfect you will have to make corrections.

I am currently helping to edit some 200 pages of some 2000 or so pages that ATLAS will release at some point in the near (I hope) future. One of the things I’m responsible? Make sure the figures are done right. Make sure everyone uses the same units. Make sure everyone is printing on A4 paper. Make sure the margins are right!

I am the margin lady! Shoot me now!

What is up with the spam today? Usually I have perhaps 5 or 6 spam messages when I first log in. Today I had over 100. And they are coming into my mailbox at the rate of about 2 per minute. This makes email almost totally useless!

Some spammer is using my email address as their fake from address. This is perfect for the spammers - they inflict all the bounce messages on someone else! How cool is that!?

I can see why folks are driven away from email. This is truly awful! I’ll not be answering much email today!

Update: More like 5 or 6 per minute right now!

Boy — you could do a lot on that kind of a vacation. You could have a nice house sitting out on the edge of an island… The penthouse for a night in downtown New York (I jest! I jest).

Well. I spent 20,000 on a vacation! Sadly, I just gave the money to Uncle Sam. Yep - Taxes! Isn’t that grand!?

The rules for working out of country are fairly complex. In general, however, our government takes a rather enlightened view towards working abroad: if you get paid out of country they are willing to give you a rather hefty tax break on that money. Which makes sense, really - if you are out of country you aren’t using as many of the services you would normally be if you were working in country. And besides, the more Americans working abroad, the better for our country’s image and also better because they will learn new things and bring them back!

However, while enlightened, they have some rather strict rules about what “out of country” means. And we violated them. If the rules had been for “out of seattle” instead of “out of the USA” then that cool $20,000 would have been sitting in my bank account! It was the Christmas trip back to the USA that did it. We were back in the USA for one full month. Some vacation and a bunch of work for both of us. What is really bad is that most of this is going to hit us on next year’s taxes. That combined with the weak dollar is going to make this year suck!

Actually, given the type of career that Paula and I have I don’t think we could work out of the country and also satisfy these rules - we have to travel back to the USA too frequently. Which is really unfortunate!

Ok, this wasn’t April 1st, rather April 4th. What is worse is CMS saw him first. Darn!

That picture is of the ATLAS detector and Peter Higgs, the fellow whose last name is attached to the Higgs particle - the particle that all of us are after.

See? ATLAS saw him!

Coincidentally an email conversation broke out on a D0 mailing list around the time of this picture discussing the origins of the Higgs mechanism. It was sparked by this yahoo news article. The title is “‘God particle’ expected to be found soon.” Hmmm. Expected to be found? Not sure we are that sure… At any rate.

The email conversation was interesting because because it pointed out that in science often more than one person has the same idea at the same time. Discovery is partly having all the bits in place to build the discovery on. Once all the bits are in place then several people can make the leap.

I’m not familiar with this bit of history, besides Peter Higgs, there was also Robert Brout, Francois Englert, and Tom Kibble in Europe. There are two in America too - Gerald Guralnik and C.R. Hagen. I note that on the Englert page what we normally call the Higgs mechanism is called the Brout-Englert-Higgs mechanism. On the Kibble page it notes that he is credited with the co-discovery of the Higgs with Guralnik and Hagen, the beauty of wikipedia! [they are all basically right, I believe]. Oh — hey — and the UR home page has something up about Hagen as well.

I went to the University of Rochester for my graduate work and my quantum mechanics class was taught by Hagen. At the time I didn’t fully appreciate the work he had done.