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Archive for January, 2010

Getting fired up again!

Sunday, January 31st, 2010

As the time approaches for the reinitiation of LHC operations, we are starting to feel the excitement  of this grandiose experiment again.

With the Tevatron’s first direct constraint on the mass of the Higgs boson beyond good-old LEP’s this past week, physicists in all LHC experiments are getting ready and more excited to re-start operations and finally gather some data that allow them to search for new physics and hopefully complement or surpass very quickly the astonishing Tevatron results.  Meanwhile, LHC physicists and engineers are finalizing the improvements in the quench protection systems that will allow us to run at the energy of 3.5 TeV/beam, starting middle February.

My two cents, as always, consists of collaborating in putting the CMS trigger system in the best condition possible to start taking good data.  This time though, we are using “real” data from last year’s operations as opposed to using “simulated” data.  No more relying entirely on Monte Carlo, no more tweaking and tuning and speculating about our computer simulations.  This is the real deal guys!!

What we do with the data is to skim it off-line into a collection of good and interesting events, then we feed them into our on-line system and run the trigger menu to check its performance.  These data has all the information, event by event, that the detector collected (in the form of electronic signals) from those proton-proton collisions we had last year.  For these past month or so, we have been capable of touching nature’s primary constituents over and over in order to adapt our detectors and tune them to be able to better sense the most fantastic petals of life: particles!

Edgar Carrera (Boston University)


Funny Article

Friday, January 29th, 2010

bonkers_thumb So as I was cruising through the world of the inter-web I stumbled upon a funny and interesting article over at physics.org entitled

Top 4 Bonkers Things about the Universe

Besides the bananas floating in space, what caught my attention was the quote at the bottom of the page

But they key thing – and this has got to do with quantum theory and I won’t go into it – the key thing is that there are only a finite number of possible histories. Now, if we have only a finite number of histories and an infinite number of places for those histories to be played out, then it follows that every possible history happens an infinite number of times.

This is an interesting interpretation of what I’ve often heard of referred to (correctly or incorrectly) as “many worlds” or “multiverse” interpretation of quantum mechanics.

Strictly speaking, as an aspiring experimental particle physicists, I leave such ideas and notions at an arms length until I hear how this would have any experimental ramification or testability. That isn’t to say I don’t let my imagination wonder to the possibilities presented here…but more so I don’t spend too much time pondering them in depth.

elvisHowever, as was pointed out in a related article, Elvis is alive and kicking…in a parallel universe this could have huge experimental ramifications! The King will Never Die! 😉


I recently found myself spending a lot of time thinking about science outreach and so was particularly tickled by an article in The Onion about the dumbing down of science. The Onion, of course, is “America’s finest [satirical] news source.” Included in the piece:

Sources pointed to a number of proposed shows they’ve abandoned in recent weeks, including […] Atom Smashers, a series that was was roundly rejected by focus groups as being “too technical” and “not awesome enough.” “People liked that the particle accelerators were really huge, but apparently the show didn’t have enough smashing to hold their interest,” said a former employee.

I don’t own a television (is that weird?) so I don’t really know what programming is like on the Science Channel, but as a particle physicist I am often confronted with the question of how to explain my research to the public in a way that does not speak down to either the audience or the subject.

It is true that high energy physics isn’t a field which most people have everyday contact with, but this doesn’t mean that the material needs to be “dumbed down.” While the material might be unfamiliar to the audience, it is [very] wrong to assume that the audience is somehow incapable of understanding the material. In fact, it is the fault of the scientist if the audience unable to understand the material since it is part of the scientist’s responsibility to translate their technical work into something accessible to a broad audience without compromising scientific integrity.

This is not easy (though we here at US LHC are doing our best!) and there is a delicate balance between

  1. Conveying a sense of scientifically-established ‘truth’ rather than facts that people should take on faith (very unscientific!)
  2. Tailoring this argument to the interests, background, and patience of the audience
  3. Simultaneously conveying one’s personal excitement for the field.

The joke that I always keep in the back of my mind before presenting ideas to a non-technical audience is the story of an old man talking to the engineer of a steam locomotive.

The engineer does a very good job of explaining how coal is burned to boil water into steam which is then used power a system of pistons that cause the wheels to turn and the train to move forward. He explains the conversion of chemical energy to kinetic energy and the mechanics of the various valves and rods.

Eventually, the old man interrupts him and says, “Yes, yes, I understand all that. What I want you to explain is where you hide the horses.”

Flip, US LHC Blog


On Interactions

Wednesday, January 27th, 2010

For the theorist, interacting with other theorists is one of the most important sources of creative input. Our main currency is ideas, and they are seldom conceived in isolation. It is mainly for the sake of meeting and discussing with colleagues that we travel to conferences or visit other departments to give seminar talks. The ideas for almost all of the papers I have coauthored in my postdoc years have been sparked by discussions with people outside my own group.
One of the leading themes of IPMU is fostering interactions among its researchers. That’s why we have this huge interaction space in the center of our new building, and that’s why we are being lured out from our offices with coffee, tea and cookies every day.
What is special about IPMU is that it wants to foster interactions between all its researchers, be they mathematicians, particle theorists, observational astronomers, cosmologists, string theorists or particle experimentalists. IPMU is not organized in groups, but as a community. This is really different from all the places I have been before, where you were meant to talk mostly to your own crowd and were being looked at strangely for being caught talking to the people of the “wrong” floor (which, incidentally, is also why office spaces at IPMU mix all disciplines).
This community feeling has a number of positive effects. I don’t interact mostly with my peers, which form a small and highly competitive community, where people have a close eye on each other’s work and jealously guard their own. Here, I am friends with mathematicians, particle phenomenologists, experimentalists and astrophysicists, and, incidentally, also with a few fellow string theorists. This mix relaxes the atmosphere during tea time a lot.
Hanging out with a more varied crowd also gets me more exposed to other forms of physics that are not my daily bread. I am more ready to attend seminars outside my own field.
Of course people who have a good time are happier and will work better. But does actual science come from these interdisciplinary interactions?
For myself, I can say that our last paper was coauthored with a mathematician, and two more from the last two years had benefited greatly from discussions with statistical physicists. For me, it works.

I guess that giving us the possibility to interact across different fields is a way of preparing a fertile ground for great new ideas. They might not come immediately, but they find an inviting environment. And to tackle the important questions about our universe, good ideas are needed.

Il Colosseo

Il Colosseo

For my first post on quantum diaries I tried to decide if I would write it in English or in French, I finally decided not to choose and to do both. But I can’t promise I’ll do it all the time!
As I must start with something, I’ll begin with the weekend I just passed in Rome. Actually, my girlfriend and I are born the same day and I couldn’t think about a better destination to celebrate that!
It’s definitely one of my favorite city, everything is so beautiful, we can actually feel all the history behind this place and I’m sure and I don’t have to speak about the food… A couple of days are enough to see all the most famous places but it’s a real marathon!
The little bonus of this trip is that we ran into Willem Dafoe (the bad guy in spiderman), he was leaving the restaurant we were entering, if you go to Rome be sure to try this place, it’s called “Da Michele” and it’s not so far from the colosseum.
Finally, my 24th year promises to be excellent, and I hope I’ll have a lot of great stories to share on this blog.

Piazza San Pietro - Vatican

Piazza San Pietro - Vatican

Pour mon premier article sur quantum diaries je me suis demandé si je devais le faire en français ou en anglais, j’ai finalement décidé de ne pas choisir et de faire les deux. Je ne promet pas de faire toujours comme ça!
Comme il faut bien commence quelque part, je vais d’abord parler du weekend que je viens de passer à Rome. Il se trouve que ma copine et moi sommes nés à le même jour et quelle meilleure destination que Rome pour fêter ca ?!
Cela restera sans aucun doute une de mes villes préférées, le centre y est magnifique, on peut y sentir tout le poids de milliers d’années de culture et je ne parle même pas de la nourriture… Deux jours sont suffisant pour voir la majorité des lieux les plus célèbres, mais attention, c’est un vrai marathon!
Petit bonus à ce séjour, nous avons croisé Willem Dafoe (le méchant dans spiderman), il sortait d’un restaurant dans lequel nous entrions, si vous passez à Rome essayez le, il se nomme « Da Michele » et il est situé assez proche du Colisée.
Bref, ma 24ième année s’annonce excellente et j’espère avoir beaucoup de belles aventures a partager sur ce blog.


No better time…

Tuesday, January 26th, 2010

As the popular saying goes, there truly is no better time to close the barn door than after the horse has escaped… OK, it does not quite fit here, as you will see, but still I was reminded of that saying when I just passed security in Munich Airport’s Terminal 2. Just the very Terminal that was evacuated less than a week ago following a security scare that luckily turned out to be a false alarm (as they usually do). In that particular case, a laptop apparently triggered an explosives detector, but the owner of the computer disappeared, with the laptop in question, while the results from a wipedown were being evaluated. Following that, with quite a delay however, the complete terminal was evacuated. It turned out that everything was perfectly harmless, and the traveler in question probably just did not understand the security screeners’ instructions to wait for the test results… As far as I heard, there is video footage showing him wandering around the duty free shops, and then leaving the terminal with all others once the evacuation was started. Apparently he later passed security without any problems. There has been an intense debate about what all went wrong… Such as loosing track of the guy in the first place. I assume the security screeners here in Munich had to endure quite a dressing down. As a consequence, they are now extra thorough, and keeping a very close eye on laptops in particular. There is also a much increased police presence after security, to prevent anyone from leaving the area unnoticed. Luckily, my way through security was still quite fast and without trouble… I hope things stay that way, with all the new measures being discussed at present.

Now I’m waiting for my flight to Paris, which is up to now still listed as “on time”… Lets see how this develops, it has been snowing quite heavily in Munich earlier today, and quite a few flights are delayed or canceled. Hopefully I’m off soon, to attend the ILD meeting in Paris, where we’ll discuss plans to move towards a complete detector design for the International Linear Collider, to be fully worked out over the next two years.


Trial and error.

Sunday, January 24th, 2010

I have been concerned with a single problem on my research project, for about a month. Since the end of the last year, this problem stucks in my head for long long time. I have tried various ideas and calculations, but all of them failed so far. Last week, I changed the approach again, but the success is still far away. If you are a theoretical physicist, you know that I am now very much enjoying the moment of struggling. This is the most interesting and joyful part of research. I experience battle of various notions and ideas of D-brane physics, sometimes they conflic each other, sometimes they coorporate with each other to form a new interesting notion of physics. This is the moment for which I live.

I cannot tell the problem in detail here, since it is an on-going research subject. It is on a new description of nuclei, coming from D-branes and superstring theory. If this is successful, this would give a totally new description of nuclei, but… who knows if it will work out or not.

Tomorrow, again, I will experience the excitement, and the life of a scientist is like this every day.


Posters for Daya Bay

Friday, January 22nd, 2010

Hey, Seth here.  When you last met my sister, she had just graduated from MIT.  Since then, she has moved to Berkeley, gone to (and worked for)  a cooking school, and started an internship at Tikkun magazine.  I don’t mention this to indulge my brotherly instinct to make fun of her for trying so many different things — which I am the first to admit is quite unfair anyway — but rather to point you to the first results of her latest project.  As part of her magazine internship, she’s writing a series of blog entries about science, and her first piece was on the Higgs boson and its unfortunate nickname, “the God particle.”  She’s done more background research than I’ve ever done, but I’m pleased to note that her conclusions are the same as mine: that term wasn’t physicists’ idea, we don’t like it, and it keeps getting used because it’s dramatic press.  You can read what she wrote here.


Nature 1, Science 0

Thursday, January 21st, 2010
Our detector, finally inserted into the TPC

Our detector, finally inserted into the TPC

While it seems like the pace on EXO has been at 110% for over a year now, things have been ramping up even more lately. We had a ‘software week’ the first week of January where analysis, DAQ, event displays, and many other code-related tasks were discussed. I walked away with many things to do and a very short time period in which most needed to be done.

I walked away… into the salt mine. I’ve been in New Mexico at WIPP – where EXO-200 is installed – since Jan 11th and I will be here until the end of the month. I’m spending most of my time in the cleanroom working towards sealing up the cryostat – now with the detector inside. My coding work has been getting done in the evenings and has proved to be more of a challenge than I had originally anticipated.

Then – nature strikes. It is the ‘rainy season’ in California right now and apparently the weather has been proving exactly how rainy it can be. Tuesday morning SLAC and Stanford lost power due to a storm. We figured that out here at WIPP when we couldn’t access the collaboration wiki where we keep all of the documentation. No one was allowed on site with the power off, so we had a hard time getting ahold of collaborators. We get a bit done and then head home. I start up my laptop and try to ssh in… with no luck, of course. I couldn’t access any of the code I am working on since it all is on SLAC servers.

We ended up spending 2 days without documentation, without SLAC-based e-mail, without a way to access files at SLAC (like important engineering drawings), and without a way for our collaborators to get us supplies from SLAC. Never before has California rain had such an impact 2000 ft underground in New Mexico!