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Archive for March, 2010

Screen shot 2010-03-15 at 5.05.58 PM

Websites I’m used to using daily in the US deny me from visiting when I’m here at CERN.  Maybe it’s their way of telling me to get back to work – those particles aren’t going to detect themselves.

Screen shot 2010-03-15 at 5.13.37 PM

So no Pandora, no Hulu, and…

Screen shot 2010-03-15 at 5.18.48 PM…you too, youtube? Sad!



Happy Pi Day everybody!

The LHC has been running quite happily over the last few days, even ramping up the energy to 1.18 TeV – that’s 1200 times the mass of a proton, and 20% more energy than the Tevatron. ATLAS has been running and collecting data the whole time, even for the few exiting periods when there have been two beams in the machine.

At the beginning of this week we’ll have a short “technical stop.” There are a few things that the LHC guys want to try to fix. There are rules that say we may not run the machine while there are people working on it, so we’ll stop the machine for a few days. In fact, they want to open up a few areas that may be “activated” (read: a very, very, very little bit of radiation could be there). So we’ll stop, and the work on those areas will only start after about a day of waiting (when the areas have “cooled down” enough).


Because of the radiation, all the experiments have very complicated documents describing what we’ll do when the beam turns off at the end of each year. There are rules about which pieces of the detector you can work on right away, which bits you have to wait a day to work on, which bits you have to wait a week for, and so on. And all the different areas have to be marked off carefully so that no one wanders into the wrong spot!! Actually, the rules make it really safe – if you hang out in your basement a lot, you will likely get more radiation than any of the people working on the LHC.

So don’t worry too much if you don’t hear exciting news about collisions this week – we’re still working hard, and the machine will be back soon (could even be by Wednesday)! And in the meantime, enjoy some pie!!!!

Update: You can read about the weekend’s fun here



CALICE in Texas

Saturday, March 13th, 2010
Sun glinting off the panorama windows of our meeting room.

Sun glinting off the panorama windows of our meeting room.

First stop on my spring travel binge: Check. The CALICE collaboration meeting at the University of Texas at Arlington. We just finished three days of presentations and intense discussions, and I guess I had more than my fare share: Since nobody else from my group wanted to travel to the meeting (to avoid getting into the same travel-crazy mode I’m currently in), I gave a total of five presentations on various topics that we cover in my group, from data analysis to hardware development and new ideas for a beam test we will have in the fall at CERN. A big plus of the location: While Europe is still deep in Winter (I was skiing last Sunday just 50 kilometers south of Munich!), spring is in full swing here: Sunshine and temperatures in the 60’s, certainly a nice change. Of course, while we could enjoy the sunshine on our way to the meeting, the blinds in the meeting room were always drawn, to allow us to see the presentations on the screen. So, even with spring sunshine outside, we are sitting in a darkened room, discussing results and plans for hours on end… But the meeting was definitely worth it: The plans for beam tests to study calorimetry at a multi-TeV Linear Collider are coming together, and our data analysis is getting more and more mature. New results, also from my group, are about to be released, hopefully in time for the Linear Collider Conference in Beijing, China, in less than two weeks.

Wafles in the shape of Texas... Things are different here!

Wafles in the shape of Texas... Things are different here!

This is my second time in Texas, and it certainly is true: Things are bigger, or at least a bit different, in Texas. There is no escaping that: Waffles in the shape of Texas for breakfast in the morning, to just point out one thing.

Now the meeting is behind behind me, but I still have a day to spend here. The reason is flight prices: when flying intercontinental from Europe, usually the only way to get a halfway decent ticket price is to stay the night from Saturday to Sunday, and spending it on the airplane does not count. Right now this is annoying, since it stretches my trip by a day, in a period I’m barely home anyway, but it also gives me the opportunity to see a little bit of what is outside the meeting room. We already got some local flavor at the collaboration dinner at Billy Bob’s Texas two nights ago, and tonight a few of us are planning to go to a rodeo in the historic Fort Worth Stockyards. I’ve never been to one before, I’m sure it will be fun!


A physicist watches prime time

Thursday, March 11th, 2010

Hi everyone! I’ve been house-sitting for a friend and so have had a chance to catch up with some television. (Ever since grade school I would have the TV on while I did my homework… now it helps while I check calculations; I guess some things never change.)


First up was last night’s episode of the Colbert Report (on Comedy Central) in which Stephen Colbert interviewed Caltech cosmologist Sean Carroll. Sean is very well known as one of the bloggers on Cosmic Variance (the first physics blog I ever followed) and the author of an excellent general relativity textbook. He was promoting his new popular science book. Colbert has interviewed physicists in the past (including Brian Cox and Neil deGrasse Tyson), and jumped straight into the big question: what is the nature of time and why does it only go in one direction? These are rather deep questions that I suspect may be outside the realm of experimentally accessible science. (Maybe that means I should read Sean’s book?) It’s understandable that the 5 minute interview didn’t provide any concrete answers. 🙂  The quote of the evening:

“What does light, and gravity, and Einstein… and all that crap… have to do with this?”- Stephen Colbert

Here’s Sean’s description of his interview experience.

Next I should probably mention the number of hospital-themed television shows out there. (Gray’s Anatomy is insane.) Of the bunch, I’ve been told by several sources that Scrubs is the one that most accurately represents life as a resident. (Though, unfortunately, the series jumped the shark some time ago.) In fact, shows like Scrubs help my soon-to-be-doctor friends explain what it’s really like to be in med school. On the other hand, are there any TV shows that I can invoke to explain what my professional life is like? While The Big Bang Theory is a very charming show, it is more about geek culture than what life as an academic. (There are plenty of academics who aren’t geeks; at least not in the conventional way.) This week I’ve come up with a new answer: House.


Believe it or not, there are many aspects of theoretical physicis which follow House. Contrary to popular belief, I don’t spend my entire day sitting in a chair “just thinking.” (And I can’t count how many times people have asked me this.) In the same way that Dr. House’s team has to diagnose a medical mystery, theoretical physicists have to sort out our own mysteries: what controls the Higgs mechanism? What is the nature of dark matter? Why is there so much matter in the universe but so little antimatter? And in the same way that Dr. House has to navigate false-leads (it’s not lupus!) and apparently contradictory symptoms, we grapple with experimental constraints on models and thorny calculations. And here’s the point: most of the actual “thinking” in theoretical physics doesn’t come from sitting alone at a desk: it comes from animated discussions  and bouncing ideas back and forth with colleagues while scribbling at a chalkboard. (Theorists would scoff at House’s whiteboard.)

Alright, now for primetime’s nod to the “LHC is going to end the world” audience: Flashforward. This show was recommended to me by a prominent particle physicist, so I thought I’d give it a try. I’ll be honest: I don’t really have any idea what’s going on, and after several episodes into the show there are still no obvious references to the LHC. CERN has a public page about the story (originally a novel), and the US/LHC site hosting this blog has it’s own FAQ. The relevant part of the FAQ can be paraphrased:

Q: Could this really happen?
A: No.

In fact, so far there’s been very little for a physics geek to latch onto. The latest episode finally has some science jargon, some of which is worth connecting to the real world. They mention the “national linear accelerator project” in passing, a reference to the real-life International Linear Collider project. The ILC is the “precision machine” that we hope to build to follow-up on the LHC.  Next, the show’s pair of dubious physicists suspect that their experiments on “proton wakefield acceleration” was the cause of the show’s eponymous “flashfoward” event. Proton wakefield accelearation is a promising, if very nascent, avenue of research which could become the basis of particle colliders in the far future. For more about this, see SLAC’s FAQ on Flashforward.

It’s a bummer that the show’s physicists appear to have questionable morals (are they villains?), but the scene where they settle an argument by playing high-stakes poker is rather unlikely given the state of university budgets these days. (Though this doesn’t mean that being and academic isn’t a great job.) There is, however, one notable example in my mind: Michael Binger, who finished third at the World Series of Poker just after graduating from Stanford with a PhD in particle physics.

I can’t really tell if I like the show or not. The whole premise of a collective glimpse into the future is a novel plot device and there’s plenty of thick drama, but I’m not sure yet if it all comes together a good story. In other words, I’m not sure if this is going to replace Battlestar Galactica as mainstream science fiction. On a random sci-fi note, a new season of Dr. Who premiers soon. The previews promise the return of the “weeping angels,” which are my favorite examples of science fiction taking liberties with real science in order to develop a fantastic story.

Finally, the NCAA basketball tournament is looming, but in the professional league I should mention my support for my hometown Los Angeles Lakers. (This might impair my chances of landing a nice post-doc in any university in Boston.) They haven’t been playing that well recently, but hopefully things pick up. The connection to the LHC? Starting center Andrew Bynum has said that his favorite subject in high school was physics.

Anyway, that’s it for my adventures watching television.

Flip Tanedo, on behalf of the US/LHC blog


Access for People

Thursday, March 11th, 2010

Click for live LHC beam status.

We don’t let people go down underground to certain areas to check or fix things while the beam is on.  There’s always a tiny chance of losing control of a beam, or protons in the beam interacting with the beam pipe and creating other high-energy particles that could go through people.

Even when the beam is off, other hazards include the fact that the beam pipe magnets are cooled with a lot of liquid helium. The beam pipe is about 300 feet underground, so should enough of that liquid be warmed enough to turn into gas quickly it would make it hard have enough oxygen down there to breathe.

Anyway, when you see “Access” on the LHC beam status page it means people are down underground somewhere trying to check or fix something and so the beam will remain off until they’re out of harm’s way.



This past Monday we had our annual US CMS Tier-2 computing workshop. Once again, we held our workshop as part of the Open Science Grid All-Hands Meeting. Those of you who have been reading the blog for more than a year will remember that last year this meeting was held at the totally neat LIGO facility in Louisiana. This year the meeting was at totally neat…Fermilab! OK, I’ve been to Fermilab before, so no travelogue this time, but as usual it was good to meet so many collaborators face to face.

I don’t want to jinx ourselves, but I’m feeling pretty good about the state of the computing for the experiment right now. As we reviewed the status of the seven CMS Tier-2 sites in the United States and two in Brazil, we generally saw that everyone is operating pretty stably and happily. A year ago, there was a lot of discontent with existing large-scale disk storage systems. But since then we’ve developed and implemented some new systems, and there have been a lot of improvements in the existing systems, so it all just looks a lot better.

That being said, this all just dress rehearsal — we’ll see how it really goes when thousands of physicists start using the system to do hundreds of data analyses. Now that the LHC running schedule has been defined for the coming three years, we have a much better handle on the needed computing resources for for this period. Overall, we’re going to be running at lower collision rates than previously anticipated, but with pretty much the same livetime. This means that we’ll be recording the same number of events we would have at higher collision rates, implying that the density of interesting physics will be smaller. It creates a more challenging situation for the computing, but at least we now know what has to be done, and have a reasonably good idea of how to get there.

As for the second half of the title — the real excitement was on my trip home. I had an 8:10 AM flight out of O’Hare, which would arrive in Lincoln around 9:40, giving me plenty of time to be ready for my 12:30 PM class. But there was fog in Chicago, and an aircraft was late, and then the crew was swapped, and then the aircraft was sent to Peoria instead while we waited for the crew, and in the end we didn’t leave until around 10:45. The plane touched down on the runway in Lincoln at 11:57. And I was in my classroom just on time. Ah, lovely Lincoln, where the airport is small, you park right next to the airport, and you can drive to campus in minutes!


What Should I Tell Them?

Wednesday, March 10th, 2010

Towards the end of this month, I have a somewhat unusual assignment. I am to give a 1.5 hours lecture to high school students attending a math camp at IPMU. Title: “My Study”. I am supposed to talk about my experience studying and what I work on now. I guess the idea is that the high school students see how the career path of a scientist goes.
Public outreach is of course an important part of our work, so I am happy to do this. But what should I tell them?
What is important to know for someone still in school who is contemplating a career in science?
Even though this is far from filling up 1.5 hours, there are two points I personally find important which I will definitely mention: motivation and perseverance. It takes a lot of genuine interest and curiosity to become a scientist. This is what gives you the necessary motivation. It is more important than being able to perform well on the math exercises that are required in high school (I sucked at that because it was boring). Science it not something you do for the money, you must really love doing it.
The second point is that one must not be discouraged if one doesn’t understand things immediately. It’s normal that new things at first seem very hard and confusing. The point is that it takes perseverance and work to learn any topic in science. When I was studying for my final exams during the last year of university, I realized that even though I hardly ever understood new things immediately during the lectures, eventually I was able to understand everything in my textbooks and lecture notes. It often took some work, picking things apart, and going meticulously through every step in the derivation, but in the end, everything became clear.

I guess coming up with useful things to say during those 1.5 hours is going to take another bit of work and perseverance…. but by now, I should be used to that, right?


Double shift in the desert

Wednesday, March 10th, 2010

Last night was a very late night – we were underground from the beginning of the day shift to the end of the swing shift. We had to complete a ‘pump and purge’ process on our plumbing so we could pump down overnight. This process cleans out the pipes our xenon will be in, which is essential to prevent the xenon from becoming contaminated.

We started the 45 minute drive back to our house around 11:45 PM. Being in the desert in the middle of the night is amazing. From WIPP we could see Carlsbad (45 minutes away) because there were no hills or trees in the way and we were slightly elevated. I don’t simply mean seeing a glow in the sky due to light pollution, but really seeing the town itself. We pulled off the road to look at stars. Few times in my life have I seen so many stars – it would have surpassed all of them had there not been a bright oil derrick right behind us. In the 5 minutes we were stopped we saw a few shooting stars – one brighter than any star and that traversed almost half the sky. Our soundtrack were coyotes howling in the distance. This isn’t the occasional howl that defines the sound of the desert in movies, but a constant din of coyotes that sounded far enough away to not worry. It was amazing enough to make me want to work 16 hours again to witness it. But not today.


Dangerous Meat?

Tuesday, March 9th, 2010

SteaksWhen I wrote about the costs of everyday things in France (like food) compared to a typical midwestern city last fall, I focused only money.  My main interest was showing how students and other physicists who come to CERN have to change their budget from what they might be used to.

Food overall is more expensive in France, but the cost of meat is an especially noticeable difference because it is twice or more as expensive per pound as in the US.

One of the reasons why meat is so cheap in the US was mentioned in the New York Times recently (The Spread of Superbugs):

A study by the Union of Concerned Scientists found that in the United States, 70 percent of antibiotics are used to feed healthy livestock, with 14 percent more used to treat sick livestock…Dr. Martin J. Blaser, chairman of the department of medicine at New York University Langone Medical Center, and a former president of the Infectious Diseases Society of America, agrees that agricultural use of antibiotics produces cheaper meat. But he says the price may be an enormous toll in human health.

In that study by the Union of Concerned Scientists from a few years ago, they specifically mention a difference between Europe and the US:

Approximately 13.5 million pounds of antimicrobials prohibited in the European Union are used in agriculture for nontherapeutic purposes every year by U.S. livestock producers.

Basically, yeah, meat is cheaper in the US compared to France, due in part to heavy antibiotic use, but this may be leading to the development of bacteria immune to drugs we need to treat people.

Scary stuff.  Now if I could only figure out why other things are so much more expensive in France, like movie tickets and clothes…


One of our kind readers has sent us the last issue of  “the institute” magazine from the IEEE.  Its month’s question on page 9 has to do with the LHC and it reads:

Do you think the LHC is a worthwhile scientific endeavor? Will it help answer important questions about the nature of our universe?

Of course, my simple answers would be: yes and yes!  However, since  the IEEE is one of the most important (if not the most important) association related to technology and engineering,  it might be worthwhile elaborating on the answer.  Apparently anyone can make a comment to the address indicated in the magazine.


Edgar Carrera (Boston University)