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Archive for February, 2009

Into the woods, for one year

Wednesday, February 11th, 2009

My apologies to all you loyal readers and our even more loyal editors for not posting as often as might like to (or at least ought to).  I am busy teaching a large lecture course for the first time, and it is keeping me rather busy.  I’m certainly enjoying the topic of this course (electromagnetism), and am thankful for all the technology tools that we have to manage classes with large numbers of students (all homework assignments and exams are done online).  But it still takes a lot of time.  Our first midterm exam is at the end of this week.  “Are you nervous?” I asked at the start of class today.  All the students said yes, and I told them that I was nervous too.  An exam is an accountability moment for all involved; if they don’t do well, I should shoulder some of the blame.

As I work my way through the material to prepare my classes, I am struck by how much we are asking the students to learn in one semester.  If you haven’t seen any of this before, it must be quite daunting.  Now, I’ve known about this stuff for twenty years, so I can easily see the big picture, but it is harder for someone who is new to it.  Just last weekend, I was at a party, and was chatting with a friend who teaches in our Modern Languages department and some of her colleagues.  When it came out that I’m in physics, one of them noted that physics was hard for her when she took it.  “It’s not that hard!” I said.  “You just have to remember that there are really only a few concepts in play, and the rest of it is applications.”  This is totally true — electromagnetism, for instance, comes down to four basic physical laws — but of course she didn’t believe me.  It is hard to see the forest for the trees.

When the LHC turns on, there are going to be quite a lot of trees, of course, and it is going to take us a while before we figure out what the forest looks like.  When it comes to LHC physics, we’re all going to be new students who haven’t seen any of it before.  That is rather bracing, of course, but it’s also going to be a lot of fun!

While writing, I ought to comment on some other current events:

  • I think that the announced plan for LHC running is good news.  These experiments need to start accumulating some data so that we can figure out how the detectors work and how to reconstruct what is going on in them, and by planning for a long data run (into Autumn 2010), CERN is intending to give us just that.  Nothing like data to make you smarter.
  • Other bloggers here have expressed concern about the stimulus plan currently under consideration in the Congress.  I agree; I worry that it is not big enough and not fast enough.  Science projects can easily absorb and make good use of the funding that has been proposed and is now at risk.  Let’s not forget that all money goes to people eventually.  Spending on science doesn’t go into a hole in the ground (not even a hole like the LHC!); it pays people to do stuff, and those people spend their money in the economy, and so forth.  I’ve been a bit dismayed to see that a certain Senator from a certain state has been less than helpful on this front.  I called his office; it hasn’t seemed to have gotten me anywhere.

The Real News

Monday, February 9th, 2009

Heuer’s email (mentioned by Steve, so public enough for me…) suprised me in one line:

“The new schedule also permits the possible collisions of lead ions in 2010.”

Finally, at least the possibility is official.  Considering that I had never heard management mention a year for first ion collisions, this is music to my (and probably all of my heavy ion friends’) ears.

Of course while the return of the LHC was a forgone conclusion, the details were certainly not — so good news all around!


We can exhale…

Monday, February 9th, 2009

Some of us have been holding our breath all weekend, but the announcement about the LHC running schedule which was under discussion last week at Chamonix has come out. The official word will most likely appear in a Press Release from CERN – it isn’t there yet, which is a bit surprising since all CERN users got an email confirming last Friday’s news regarding the proposed schedule coming from the Chamonix workshop. Anyway, an email sent to thousands is certainly public, and there’s no warning not to disseminate, so my own synopsis – (for quotes, see press release when it arrives):

  • First beam in Sept 2009, collisions in Oct 2009
  • Short break during Holidays
  • Extended run in 2010, until Autumn

Without details I won’t speculate too much about the timeline, but certainly implementing new protections based on the lessons learned from the Sept 19 incident plays a significant role.


Brains Not Included

Friday, February 6th, 2009

2:15-hour skit for evening of 2009/02/06:

Sue Ann: Computer doesn’t have network support, problem is telephony service will not load without Blue Screen of Death.

MSTech: How are you today?

Sue Ann: Extremely frustrated.

MSTech: I am sorry to hear that.

—-[ Note to reader: Sue Ann does not need comforting, she needs a functional computer. ]—-
MSTech: Are you connecting from the machine that has the problem?

Sue Ann: That machine has no network.

MSTech: Please reinstall the display driver.

Sue Ann: Problem is telephony service. Display driver is working fine. Reinstalled anyway. Still crashing.

MSTech: Did you reinstall the display driver?

Sue Ann: Yes. It did not fix the telephony service.

MSTech: Please run this diagnostic tool and click on “send the result to M***”.

Sue Ann: That computer has no network. Your website to upload the file manually from another computer is broken.

MSTech: You just need to click on “send the result to Microsoft”.

Sue Ann: #*!&%[email protected]##%

Synopsis: Sue Ann eradicated W*** from coffee table. Sue Ann installed U*** beta. There exists at least speculation that beta is more stable than the W*** product.

Moral: This may be why high energy physicists are often their own system admins.

p.s. I do still (or perhaps more so now) retain the greatest respect for the gurus who administer these huge computing farms and grids that are the backbone of modern experimental physics.


Science is going under the knife again in Congress.

I echo Peter’s outrage, although I am starting to get jaded. Science loses again? But it isn’t over – you too can contact your senators and representatives and tell them what you think. If that doesn’t work, let the Obama administration know that this is not indicative of “putting science in its rightful place”. From the white house agenda on technology:

  • Invest in the Sciences: Double federal funding for basic research over ten years, changing the posture of our federal government to one that embraces science and technology.
  • Invest in University-Based Research: Expand research initiatives at American colleges and universities. Provide new research grants to the most outstanding early-career researchers in the country.

Doesn’t look like that right now. Maybe he would veto the bill although that is tough given the Economic situation. But at least if you want to see the US participate in the LHC and other endeavors to expand the frontiers of human knowledge, let the people who represent you know how you feel.


Senate Cuts Science Stimulus

Friday, February 6th, 2009

(via Harvey Newman at USLUO and TPM with my Keynote skills for the excerpts from pages 2 and 4…)

Like, all of it if I read this right:  Both NSF and the DOE Office of Science (already cut hugely from the House version)…

Who are these people?



Tuesday, February 3rd, 2009

People often wonder how we at ATLAS feel about those bozos our good friends at CMS, and vice versa.  The two experiments are trying to discovery exactly the same things, and as Monica discussed a while back, trying to keep from getting scooped by the other experiment will be nerve-wracking.  Personally, I like to think of CMS as the baseball team on the other side of town.  Yes, we plan to beat them at everything, every time — but deep down, we know that if they weren’t there, we couldn’t play baseball.

Obviously we don’t literally need there to be a competing detector in order to record events at the ATLAS detector or look for new physics in them, but having two detectors is actually critical to the LHC’s overall goals.  At many places — especially where new things are being tried — the detectors use different technologies.  For example, the T in ATLAS and S in CMS represent the very different magnet configurations used for the two detectors’ muon systems.  The “worst-case” reason for this is that one detector might incorporate something that never works — and while that would be terrible for the people on that experiment, it’s a lot better to have a backup that can still do the job.  But, in fact, ATLAS and CMS both work just fine so far, and we expect them to continue doing so, which brings me to the second reason that they’re complimentary: we need somebody to check our results.  Of course, we at ATLAS want to (and, needless to say, will) discover everything first — but if CMS never sees the same thing, a discovery will be pretty hard to believe.  The particle physics community really needs two detectors with different designs and different teams and different analysis strategies to get the same answer before we can be sure of what we’ve found.  (Ideally, we’d have different accelerators too, but that’s a little out of our price range nowdays.)

I’d even say it’s a friendly rivalry, more like the San Francisco Bay Area than New York or Chicago.  Although it’s hard to say — I’ve seen hats that say A’s on one side and Giants on the other, but I have yet to see any ATLAS/CMS merchandise.


Welcome to LAr week

I arrived this morning in Marrakech, Morocco, for ATLAS’s “Liquid Argon Week.” No, we’re not going out in search of liquid argon in the desert. I’m going to meet up with colleagues that I work with to make sure our part of ATLAS is ready go when the first collisions of the LHC take place.

The ATLAS experiment has many different pieces, and each piece measures different aspects of the collisions provided by the accelerator. The piece that I work on is called the Liquid Argon Calorimeter. A calorimeter is a device that measures energy. Ours is called the “Liquid Argon” (abbreviated to “LAr”) calorimeter because liquid argon is the substance inside the detector that lets us know that particles passed through it. As particles from the LHC collisions enter the argon, they ionize the argon and we can infer the energy of the particles from the ions they left behind. Argon is usually a gas at room temperature, but the gas would not be dense enough to help us measure the energy well. We have to cool the argon to -186 degrees Celsius (about -300 degrees F) to use it in ATLAS! If you want to learn more about how the calorimeter works, I recommend this video which explains many of the ATLAS subsystems with great illustrations. There are actually four different types of liquid argon calorimeters used in ATLAS, but they share many of the same tools and challenges, so all the people working on those detectors form the “Liquid Argon Calorimeter Group” within ATLAS.

People who work on these calorimeters get together every few months to share their progress and make plans for the future. The same thing is done for other systems of ATLAS: there is a “muon detector week” and an “inner detector week” and then there are weeks for all of ATLAS to get together. Usually these weeks are at held at CERN, but once a year, they may be held outside CERN. The outside-of-CERN weeks give one of the groups a chance to show their colleagues around their home town. It also gives people from that area a break from travelling all the way to CERN. Being away also allows/forces people to get away from their usual offices, tasks, and social circles at CERN. There are scheduled talks, and a lot of other important and useful discussions take place over coffee (or mint tea!) or lunch or dinner while people are away
from home, together.

This week, our Liquid Argon Calorimeter colleagues from Morocco have invited us all to meet in Marrakech. We’ll have four days of meetings on different topics relating to the calorimeters, and then a free day at the end of the week for exploring. There will be a big dinner one night with Moroccan food — I’m looking forward to that!