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Nicole Ackerman | SLAC | USA

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End of quarter, new beginnings

Tuesday, June 9th, 2009

Stanford finishes spring quarter incredibly late, so this is my first week without any teaching responsibilities. While I really enjoyed teaching this past quarter, it too up much more of my time than I anticipated. I had thought I would spend one day a week on campus, and perhaps half a day grading. Instead, I found myself on campus at least two days a week and grading would be a good chunk of another day.

With the end of this quarter, I am now at SLAC full time. Even before this quarter I spent a significant amount of time down on Stanford’s campus in the clean room building our detector and taking classes. Last Friday I found myself sitting at SLAC in front of the mess my desk had become, and I realized that this desk will be a second home to me for the next few years. There will be some more trips to WIPP and at least two more quarters teaching, but for at least the next year I will spend more than 80% of my work hours at that desk. So I cleaned it, and it felt great.

In addition to getting my desk organized, I’m also trying to sort out the projects that were somewhat neglected last quarter. I’ve been working on creating an electronics test stand to mimic what we are installing at WIPP. I thought it would be done over a month ago, but most of the pieces have still not come together. I hadn’t realized chasing power supplies would be too difficult to get done in 3 day weeks. I also have been thinking about a phenomenology project since January. I already did the first literature search, so now I need to begin organizing all of the papers I have on the topic and start trying to understand the details of the physics. I’m very excited about making progress on my understanding, but it requires an amount of uninterrupted concentration I have not had for many months.

Finally, I hoped to start afresh with my computer. I run Ubuntu on my laptop and one of the perks of an open-source operating system are the frequent new releases. I hadn’t yet updated to Jaunty Jackalope, which has been out for over a month. I spent the weekend backing my hard drive up and installing the new OS. I also restructured my desktop environment and was hoping to redo a few more configurations. Unfortunately I’m running into some bugs in Jaunty, so the experience hasn’t been as refreshing as I had expected.

June may be too late for “spring cleaning”, but it still managed to be a great fresh start. I look forward to a better organized, more productive schedule. And more blog posts!

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“Science News Cycle”

Wednesday, May 20th, 2009

PhD Comics were started by a Stanford Student and (humorously) chronicles the graduate experience. I started reading them while an undergraduate at MIT, and now I find them even closer to home as a grad at Stanford.

PhD Comics

PhD Comics

This week the topic strayed a bit from the normal topic of “grad school” but still certainly hit its mark: The Science News Cycle.

The comic certainly brings to mind the news “coverage” of the LHC, and how it mostly focused on one guy thinking the LHC might destroy the world. Even my family – who have spent years listening to me talk about the LHC – kept asking if it was going to destroy the world. I worry that Angels and Demons will have a similar effect. Scientists may give public lectures to clarify the fact and fiction in the movie/book, but the media thrives off scandal and fear.

While some science news coverage can be accurate, insightful, and (most importantly) correct, that sort of coverage usually is confined to science-specific publications. This isn’t always true! My father has continued subscriptions to Discover and Scientific American magazines that I received in high school. He was once telling me about an article describing “what I do” as leading to transporter technology in the next decade or so. I couldn’t imagine how anyone would say that, and thought he was misreading the article. The next time I visited he showed me the article, which said current particle physics research will provide transporter (a la Star Trek) technology very soon. I have no idea how the author had come to that conclusion, because I certainly haven’t seen any transporters in the work.

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Accessibility in Physics

Tuesday, May 12th, 2009

CKM Parameters (RG colorblind)

CKM Parameters (RG colorblind)


One of the best known modern physicists is confined to a wheelchair. One could then think that experimental halls would be cutting edge with ramps and wide hallways. This is certainly not the case, but the lack of wheelchair accessibility is likely due to the age of the buildings. My building at SLAC doesn’t have an elevator, but the building nextdoor has two. It is possible to get to the second floor of the other building and come directly to my building, but the passageway is blocked due to construction. Presumably accommodations would have been made had someone needed the elevator regularly. Back at MIT I worked on a floor only reachable by stairs and a freight elevator which a prominently displayed “no passengers” sign. These problems are inherent to old buildings, so physics is likely no better or worse than other fields for wheelchair accessibility.

Fluctuations in CMB (RG Colorblind)

Fluctuations in CMB (RG Colorblind)

What about something like color blindness? Physics relies heavily on color as a way to present lots of information at once. A graph can have over a dozen different lines and regions – representing different theories or measurements – each one a different color and pattern. Astrophysics data is often represented as a color field plot since the goal is to show variation over the 2-dimensional sky. Luckily, the color palettes for these images are usually chosen well. As a scientist I never think about these things – I use the default color schemes of my plotting programs. I also know how important they can be: the COBE/WMAP data would not be as nuanced if in black and white, and the complicated Standard Model parameter plots would be indiscernible without many colors.

This issue caught me off-guard in the class I TA. We were studying spectroscopy, so students were supposed to identify and measure the different colored lines of Mercury, Sodium, or Hydrogen. One student was having difficulty, since he wasn’t sure what color line he was seeing. This shouldn’t have been such a surprise to me – both of my Junior High science teachers were color blind.

Mercury Spectrum, which actually spans the full spectrum (RG Colorblind)

Mercury Spectrum, which actually spans the full spectrum (RG Colorblind)

I’m sure I’ve been guilty of quickly trying to explain a plot by stating the meaning of the red, blue, or green lines on a plot during a talk. While my student was able to ask his lab mates to help identify the color of the line, an audience member may not be able to clarify whether I am referring to the top and bottom line. I know I’ve put colored text over other colors (such as in a CAD drawing) – were the labels clear to everyone? If 7% of men in the US can’t distinguish red from green, there is a good chance a few people are seeing a well-attended talk different from everyone else.

While I can’t install more elevators, I can make my talks accessible to people with red-green colorblindness. The tool I used to generate the images is Vischeck, and there are many more tools available to help develop color palettes and check images.

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Conversations with the US Government

Tuesday, May 12th, 2009

I know I am not the only scientist who cringed over the relationship between science and the recent Bush Administration. Myself and others were overjoyed about the extent that science was part of Barack Obama’s campaign speeches (if only sometimes a mention). Now that a new Administration is in Washington, it is pleasant to see some things may be changing.

The Office of Science and Technology Policy has a blog, and the President has used it to request comments on a recent memorandum on scientific integrity. The comment period ends on Wednesday (May 13th), so if you believe you have input – please go and contribute! It’s amazing that by simply commenting on a blog I could influence science policy.

Some communication methods have stayed the same, even with the change of Administration. Every year there is a lobbying group of particle physicists who go to Washington to speak with congressional representatives. It is part of a complicated funding system that I hope the blog about later, but it boils down to a need to convince Congress that it is valuable to provide money to the organizations that fund particle physics. This year the group was comprised of SLAC Users, Fermilab Users, and US LHC representatives. The conversations between scientists and government officials aren’t just lectures on the important of the neutrino mass or Higg’s Boson – Congress had some things to say to scientists as well.

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EXO in Symmetry Breaking!

Thursday, May 7th, 2009

I spend too little time tracking scientific news – such as perusing the latest papers in relevent journals – but I am kept somewhat up-to-date by SLAC Today, a daily newsletter delivered to my inbox containing both science news and more general info for the SLAC community. Today I was interested to see there was an article on EXO, which was an excerpt from a Symmetry Breaking story on EXO. The story focuses on the barium grabbing work done by many of the groups in our collaboration. Since it isn’t an aspect I’m involved in at all, I even learned something from reading it!

My Favorite Symmetry Cover

My Favorite Symmetry Cover

The only way I usually see notable science outside of particle physics is through BBC news. While I have some trust in their international affairs coverage, their science coverages seems less reliable. I can’t judge their medical or environmental coverage, but their physics coverage is quite disappointing. I’m glad magazines like Symmetry exist to provide factual information to those who don’t have the expertise to differentiate the science from the sensationalism (that is often sells issues and books and movies…).

My step-father, a reporter for a regional newspaper in Ohio, received an issue of Symmetry out of the blue in 2004. He has covered science topics before, which is why we think he received a copy. I was excited to read it, as I was a college freshman at the time and interested in particle physics. It presents real physicists, their research, and the big ideas in a straightforward manner. While it might not be as exciting as a Dan Brown novel, you can be sure everything you are reading is actually true! I find it valuable as a guide to communicating science. Their “explain it in 60 seconds” articles usually cover a topic I am familiar with, but provide a great example of how I can share it with my grandparents or a person sitting next to me on a plane. Their May 2005 cover (shown right) is the best representation I have seen of the non-orthogonality of the mass/CP eigenstates of the neutrinos!

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Defending the University

Wednesday, April 29th, 2009

A recent op-ed in the New York times demanded that we “End the University as We Know It”! Interestingly, it is written by the chairman of a religion department. His general claim is that the departmental structure and attitude of the university system is out of date and not very useful. He envisions universities structured around topics like water, where people from engineering, social science, natural science, and humanities would come together to solve problems. He sees over-specialty (“research in subfields within subfields”) as a problem.

I’m not the first to criticize his view – there have been 437 comments on the nytimes website – and much of my initial reaction has been stated rather well at the Female Science Professor Blog. I specifically take issue with the idea that the material learned as an undergraduate (or in graduate school) is not, in itself, useful. This is not true in all cases. The basic quantum mechanics, electromagnetism, and statistical mechanics I learned as an undergraduate paved the way for the graduate material on these topics. Understanding these fundamentals then allows one to understand how superconductors and other novel materials work – this allows one to design a better hard drive. The level of specialty required for that sort of work is not what someone can learn in a broad interdisciplinary program!

Restructuring education around “big problems” would mean all of the small problems would slip through the cracks. Plenty of great technologies did not originate intentionally. The internet is a classic example – few realized how much it would expand beyond a few scientists using it to communicate – accelerators and radiation are another. Physicists made accelerators to study the building blocks of matter, and they are now used to treat cancers. I have a hard time believing that an interdisciplinary group working to treat cancer (in a world where particle accelerators didn’t exist) would decide to create accelerator technology. The research that only interests a few people may simply be so groundbreaking that more have not yet learned the necessary skills or approaches to participate. The op-ed seems to believe that the existence of narrow fields precludes interdisciplinary work and changing departments. While an undergraduate at MIT I saw the Ocean Engineering program end and the BioEngineering program begin. I fear his vision of the University would end so much of the exciting work done in physics, and the current University system is welcoming of interdisciplinary work, perhaps the op-ed’s knowledge isn’t relevant to any of it.

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Space-pig flu

Tuesday, April 28th, 2009

Every time I get ill I tend to joke about it being the plague or something horrible (and implausible). This past weekend my illness actually coincided with the swine flu, so the joke was not too funny. Since I don’t know anyone who has been to Mexico lately (and Tom was sick a few days before me, before the scare) I am fairly sure I am just a victim of the rhinovirus. Unfortunately I was supposed to go SCUBA diving this weekend, so my mild cold cost me some productivity and a trip to play with the starfish in Monterey!

In true Ackerman style, I decided to watch The Andromeda Strain. This is the sort of black humor my family believes in – my father often watches The Perfect Storm on his sailboat, which is the same type as is shown destroyed in the movie. I consider myself an avid fan of old sci-fi, especially anything dystopian in nature. The Andromeda Strain wasn’t quite what I was expecting, but I enjoyed it immensely. The movie is about a satellite that appears to have brought back a deadly germ from space and the scientists that study it (in order to save the world). It is notable for a few things:

  • A female scientist! She is simply treated as one of the scientists, rather than serving as eye-candy. I believe this is one of the first (if not the first) movies to have a believable female scientist.
  • The obstacles of science being portrayed reasonably. The scientists are hampered by the limits of technology – silly little things, like a mechanical failure and communication issues. Those are the things that slow science down!
  • A ridiculous level of cleanliness. These scientists were worried about biological cleanliness (ie, not introducing bacteria and fungi into the research area), rather than the radiological cleanliness that we worry about on EXO. The steps they had to go through to enter the clean area certainly belonged in sci-fi, rather than an actual lab, but it was comforting to see we don’t have it the worst on EXO! It took them hours to get to their labs – it only takes us a few minute to put on gloves, hair bonnet, clean room suit, and go through the air shower.

The scientists in the movie were normal researchers who were part of a group brought together in the case of an alien germ. It’s exciting to think of scientists getting to save the world (without weapons). So government, if you’re reading this, feel free to give me a call!

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Duplicates

Saturday, April 25th, 2009

In high school I did competitive robotics through US FIRST Robotics on Team RUSH. If you aren’t familiar with the program, teams of high school students are mentored by professional engineers to build and compete with a robot. A new game is presented every year in January and the teams have less than 2 months to design and build the robot. This was not ‘battle bots’ – there was a focus on learning and competition.

One of the many lessons I learned on the team was to build duplicates. We had to build and ship the robot by a certain day, but it wasn’t yet time to compete. We would have time at the competition to make mechanical and software improvements to the robot, but we had to have a way of developing them. At the time the Detroit auto industry hadn’t collapsed (the numerous Michigan teams are primarily sponsored by auto engineering firms) so we had enough resources to build our own competition field and and an additional robot. This meant that we could practice our driving and strategy while our competition robot was on the way to the first competition of the season.

Can this lesson apply to physics? The amount of time and money to build the robot seemed immense at the time, but are orders of magnitude less than what it takes to build a particle physics experiment. We certainly can’t build two cryostats out of clean copper and only send one to WIPP. But we did build a mock-up of our time projection chamber to begin the build process. We have such delicate parts that trying the assembly outside of a clean room first meant we had practice before we assembled the real thing. This didn’t even double the cost of the TPC – we had ordered parts with plenty of extras and built the mock-up out of flawed parts that would not have been suitable for the real TPC. Some parts weren’t made of pure materials and others weren’t plated in expensive conducting metals, like the real parts are.

Now we are trying to create a duplicate electronics structure. The detector is built and attached to the read out electronics, so we are debugging the electronics and software to acquire data. While some collaborators are switching board positions and adjusting voltages, I’m trying to fix the software. It is quite the tango – it is hard to tell if some problems are in hardware or software and sometimes one group makes changes that mess up the other group’s debugging. Having a test electronics system with the minimum hardware and computers to test the software means that the two processes will be able to work independently. Once the real electronics system is installed at WIPP (and the bugs are out of the software!) we can use the test system to work on upgrades to the electronics without interfering with the data runs at WIPP. We can even use it for developing prototypes for readout systems for ton-scale EXO.

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Moving Physics Bits

Wednesday, April 22nd, 2009

I work on a very hard experiment. Most experiments are hard, even outside of particle physics – it has been a very long time since anyone could simply drop two objects and learn something new. In my experiment we have to worry about the number of Uranium atoms in a few tons of copper. We had to find ways to make electrical contacts and carry signals without the normal mechanisms of solder or wires. We have a cleanroom that we shipped from Stanford, CA to Carlsbad, NM and then put 2000 ft underground in a salt mine. My collaborators are researching ways to grab a single barium ion and identify it with lasers. My experiment has overcome a lot of obstacles, but in some ways the most recent problem is the most bizarre: how do you get the data out of the salt mine?

Particle physics experiments usually result in huge amounts of data, which always pose a challenge to process and store. The LHC experiments see Terabytes (1000 GB) of raw data a second, which is filtered and recorded at around 1.8 GB a second. Our maximum rate is around 80 MB/s (about 4% the LHC rate), which we will sustain for a few hours during our calibration periods. The big collider experiments have way more data, but they also are within state of the art computing facilities. My home network can’t handle our data rate, but the almost any academic network could. If we were trying to get this data from one side of SLAC to another, it wouldn’t be much of a problem. However, we are trying to get it out of a government salt mine.

WIPP Entrance (note fence)

WIPP Entrance (note the fence)

The WIPP site has incredible security, which I’m sure everyone appreciates since it is a nuclear waste storage site. However, their security protocols mean we can’t use their network. We have our own 1.5 MB/s network going in to the mine. At least the last time I was there (back in October), the network wasn’t always working. It will never be good enough for transferring our data. It is barely enough to transmit commands to control the experiment remotely, such as when the mine is closed. We looked into trying to get a better connection, but that would mean getting a new line installed between WIPP and Carlsbad, which is something like 35 miles. It might be cheaper to get our data to the moon!

Since the data can’t get out via wires, we are left with a choice between tapes and hard drives. Tape drives might seem old-fashioned, but they are still used in science. They are less fragile than hard drives and giant tape-loading robots simplify the data transfer process. The fragility is an issue since we will be shipping the drives back and forth between WIPP and SLAC. Our collaboration has found only one experiment so far (SAUND, in the Bahamas) that ships hard drives. Their data volume is also less than ours – we’ll be practically juggling disks going back and forth. We’ll have the delays of transferring the data from the WIPP computers to the drive to be shipped (or at least backing it up), the transit time, and then the time of getting it off the transfer disk.

So forget determining the neutrino mass – that’s easy.  How do we get our data from WIPP to SLAC with the minimum delay and cost?  Moving those bits, with all of our physics in them – that’s hard.

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The Fun Side of Physics

Saturday, April 18th, 2009

I happen to think that there are many fun aspects of physics, but I realize not everyone finds C++ programming or spinor algebra interesting.  A large part of what makes this enjoyable (for me) is the puzzle-solving aspect, especially when the little tasks are very disconnected from the physics they are eventually useful for.

For those not motivated by neutrino masses, or simply sick of debugging code, there are many distractions out there that vaguely tie to physics.

  1. Quarked! is a project to present subatomic physics to 7-12 year olds. While there are many aspects to this project, the games are my favorite, especially the Baryon Blaster. If they had an “advanced” level on this I think I’d manage to memorize all of the baryons’ composition!
  2. The Particle Zoo is a source of cute plush “particles”, including particles us physicists have a hard time finding! I got a set awhile ago including the neutrino, electron, muon, and tau. My neutrino hangs out with me at work and the muon often gets tossed around at home.
  3. KSpaceDuel is my favorite computer game (only for linux). You have a satellite, orbiting a star, and your goal is to destroy your enemy’s satellite through bullets and mines. The bullets and satellites are effected by the gravitation of the star, so predicting trajectories is essential.
  4. PhET offers a bunch of interactive science simulations. While they are practical, educational tools, they can also be used as a source of fun. Most of them have a built-in failure mode – getting a laser locked is fun, but blowing it up is better.
  5. Star Formation: The Game! The physics gets harder every level, just like actual research! My high score is 22,118 so far, with a chain of 66 stars formed.
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