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Mentoring tomorrow’s scientistsVector

Whether they’re 8 or 18, tomorrow’s scientists benefit from one-on-one mentoring from those who were once in their shoes. Over the years, Quantum Diarists have mentored and encouraged a wide range of students, helping them better understand what it means to be a scientist and develop the tools they’ll need to get there.

Finding tomorrow’s scientists

By Aidan Randle-Conde | September 2, 2014
The road to being a scientist is a long one and you’ve got to really want it and work hard to get there. Calvin, a distant relative I met last week at a family reunion, has what it takes.

Visiting my high school in Arkansas

By Kyle Cranmer Tanedo | November 21, 2013
The Arkansas School for Mathematics, Science & the Arts changed my life, and tomorrow I leave to go visit the school 20 years later. I look forward to telling the students about the tremendously exciting career I’ve had in particle physics, culminating in the discovery of the Higgs boson.

Welcome to college, future colleagues (advice for science undergrads)

By Flip Tanedo | September 12, 2010
It’s the beginning of another academic year, which means another generation of young people entering universities across the US. I have a strong belief that one of the roles of the graduate student community is to provide mentors for undergraduates, especially those who are interested in pursuing academic careers. To that extent, there are a few things that I always thought I would have appreciated knowing when I was a freshman and that I’d like to share with the blogosphere.

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This article appeared in Fermilab Today on Sept. 5, 2014.

This aerial view shows the Neutrino Area under construction in May 1971. The 15-foot bubble chamber, pictured on the left, would later be moved to the present-day location of Lab D.  Photo: Fermilab

This aerial view shows the Neutrino Area under construction in May 1971. The 15-foot bubble chamber, pictured on the left, would later be moved to the present-day location of Lab B. Photo: Fermilab

It was called Target Station C. One of three stations north of Wilson Hall at the end of beamlines extending from the Main Ring (later replaced by the Tevatron), Target Station C was assigned to experiments that would require high beam intensities for investigating neutrino interactions, according to a 1968 design report.

Within a few years, Target Station C was officially renamed the Neutrino Area. It was the first named fixed-target area and the first to be fully operational. Neutrinos and the Intensity Frontier had an early relationship with Fermilab. But why is it resurfacing now?

“The experimental program is driven by the current state of knowledge, and that’s always changing,” said Jeffrey Appel, a retired Fermilab physicist and assistant laboratory director who started research at the lab in 1972.

When Appel first arrived, there was intense interest in neutrinos because the weak force was poorly understood, and neutral currents were still a controversial idea. Fermilab joined forces with many institutions both in and outside the United States, and throughout the 1970s and early 1980s, neutrinos generated from protons in the Main Ring crashed through a 15-foot bubble chamber filled with super-heated liquid hydrogen. Other experiments running in parallel recorded neutrino interactions in iron and scintillator.

“The goal was to look for the W and Z produced in neutrino interactions,” said Appel. “So the priority for getting the beam up first and the priority for getting the detectors built and installed was on that program in those days.”

It turns out that the W and Z bosons are too massive to have been produced this way and had to wait to be discovered at colliding-beam experiments. As soon as the Tevatron was ready for colliding beams in 1985, the transition began at Fermilab from fixed-target areas to high-energy particle colliding.

More recent revelations have shown that neutrinos have mass. These findings have raised new questions that need answers. In 1988, plans were laid to add the Main Injector to the Fermilab campus, partly to boost the capabilities of the Tevatron, but also, according to one report, because “intense beams of neutral kaons and neutrinos would provide a unique facility for CP violation and neutrino oscillation experiments.”

Although neutrino research was a smaller fraction of the lab’s program during Tevatron operations, it was far from dormant. Two great accomplishments in neutrino research occurred in this time period: One was the most precise neutrino measurement of the strength of the weak interaction by the NuTeV experiment. The other was when the DONUT experiment achieved its goal of making the first direct observation of the tau neutrino in 2000.

“In the ’90s most evidence of neutrinos changing flavors was coming from natural sources. But this inspired a whole new generation of accelerator-based neutrino experiments,” said Deborah Harris, co-spokesperson for the MINERvA neutrino experiment. “That’s when Fermilab changed gears to make lower-energy but very intense neutrino beams that were uniquely suited for oscillation physics.”

In partnership with institutions around the globe, Fermilab began planning and building a suite of neutrino experiments. MiniBooNE and MINOS started running in the early 2000s and MINERvA started in 2010. MicroBooNE and NOvA are starting their runs this year.

Now the lab is working with other institutions to establish a Long-Baseline Neutrino Facility at the laboratory and advance its short-baseline neutrino research program. As Fermilab strengthens its international partnerships in all its neutrino experiments, it is also working to position itself as the home of the world’s forefront neutrino research.

“The combination of the completion of the Tevatron program and the new questions about neutrinos means that it’s an opportune time to redefine the focus of Fermilab,” Appel explained.

“Everybody says: ‘It’s not like the old days,’ and it’s always true,” Appel said. “Experiments are bigger and more expensive, but people are just as excited about what they’re doing.”

He added, “It’s different now but just as exciting, if not more so.”

Troy Rummler

Special thanks go to Fermilab archivists Valerie Higgins and Adrienne Kolb for helping navigate Fermilab’s many resources on early neutrino research at the laboratory.


For my inaugural post a few months ago I discussed dark matter direct detection and the search for WIMPs deep underground. As a graduate student on the Large Underground Xenon (LUX) experiment, this is the area that I am most familiar with, but it is by no means the only way to hunt for these elusive particles. The very idea of dark matter was first motivated by problems in astronomy (such as understanding the rotation curves of galaxies), so what better way to look for it than to turn our telescopes to the skies?

The best way to get an intuition for the physics behind dark matter detection is to look at the Feynman diagrams representing interactions between dark matter particles and standard model particles. For example, the relevant interactions in the direct detection of WIMPS have the general form:


Feynman diagrams are conventionally drawn with time as the horizontal axis, increasing as you go from left to right. In this particular diagram a WIMP χ and a standard model particle, which I somewhat un-creatively call sm, come in from the left, interact at the vertex of the diagram, and then a WIMP χ and a standard model particle sm, leave on the right. (Here I have deliberately obscured the vertex, since there are many possible interactions and combinations of interactions that yield Feynman diagrams with the same initial and final particle states.) More succinctly, we can think of this diagram as a WIMP χ and a standard model particle sm scattering off each other.  Direct detection experiments like LUX or the Cryogenic Dark Matter Search (CDMS) look specifically for WIMPs scattering off protons or neutrons in an atomic nucleus, so the relevant Feynman diagrams are:


Feynman diagrams are kind of beautiful in that you can draw a diagram for most any particle interaction you can think of; you can flip it, rotate it, and smoosh it around; and because of certain symmetry considerations you will in general still end up with something representing a completely valid, physically-allowed particle interaction.

Let’s do this with our direct detection diagram. If we just rotate it a quarter-turn, we end up with the following:


We can interpret this as a two WIMPs colliding and annihilating to form standard model particles in a way analogous to how electron-positron annihilation produces photons. WIMPs might be Majorana particles, i.e. their own antiparticles, or they might be Dirac particles, that is, distinct from anti-WIMPs, but the bottom line is still the same: the detection of the annihilation products can be used to deduce the presence of the initial WIMPs. (It might also be that WIMPs are unstable and therefore decay into standard model particles, in which case we could also look for their decay products.)

“Indirect” detection is the rather apt name for the technique of searching for WIMPs by trying to detect the products of their annihilation to standard model particles.

This strategy presents an entirely different set of challenges than direct detection. For one thing, you can’t shield against backgrounds in the same way that you can with direct detection experiments. After all, your signal consists of ordinary standard model particles, albeit standard model particles from an exotic origin, so any attempt to shield your experiment will just block out your desired signal along with the background. So where LUX is a “zero-background” experiment, indirect detection experiments look for signals that manifest themselves as tiny excesses of events over and above a large background. Additionally, indirect detection requires that WIMPs in the universe be both abundant enough and close enough together that there is a non-negligible probability for annihilation to occur. If in fact WIMPs are the answer to the dark matter problem then this was most certainly true in the early universe, but today, cosmologists estimate the local density of WIMPs to be approximately 0.3 GeV/c2/cm3. This corresponds to only about three WIMPs per cubic meter! This is a challenge indeed, but luckily there are a few places in the universe where gravity helps us out.

First of all, we can look for WIMPs in the centers of galaxies, where gravity helps coalesce both standard model and exotic massive particles into higher-density clumps. Here there are a number of annihilation processes we can search for. For instance, we can look for WIMPs annihilating directly into gamma rays, in which case the signal would be a mono-energetic peak in the gamma ray spectrum:


Note that as in my direct detection diagrams I have deliberately obscured the vertex of this diagram. Because WIMPs by definition do not interact electromagnetically they cannot convert directly into photons. However, the interaction represented in this particular diagram could take place if it contains an intermediate step where WIMPs convert first into a non-photon standard model particle. Then this intermediate particle could produce a photon final state.

The galactic center is not the easiest place to search for rare events. Here, the hunt for gammas from WIMP annihilations is complicated by the existence of many bright, diffuse gamma backgrounds in the from astrophysical processes that are not necessarily well-understood. In addition, the density profile of our WIMP halo is not well-understood near the center of our galaxy. It might be that our dark matter halo has a very dense “cusp” near the center; on the other hand it might very well be that the dark matter density in our halo increases up to a point but then plateaus to a constant density toward the center of the galaxy. Regarding the latter, understanding this density profile is an active area of research in computational and observational cosmology today. After all, if we don’t know how much dark matter is in the center of our galaxy, then how can we predict what an annihilation signal in that location might look like?

In order to mitigate the first of these complications, we can look to galaxies other than our own. In the Milky Way’s Local Group there are a number of galaxies called “dwarf spheroidals” which have extremely low luminosities, little to no interstellar gas and dust, and as a result, much less overall background than in our own galaxy. This sort of environment might therefore be very conducive to the indirect detection of WIMPs.

We can also look for WIMPs annihilating into heavy standard model particles. Generally these decay rapidly, producing jets that in turn yield a whole continuous spectrum of gammas and other particles. Schematically, we can summarize this process as:


Perhaps the most interesting products of these annihilations are the antimatter particles produced in these jets. The matter/antimatter asymmetry in the universe is a whole other mystery to be solved, but it does provide for us a fairly conclusive smoking-gun WIMP signal. Antimatter in the universe is rare enough that a large flux of antimatter particles could suggest WIMP annihilation events are taking place. Some classes of indirect detection experiments look for positron excesses; others look for antiprotons or antideuterons. On the other hand, these experiments are also complicated by the existence of other cosmic-ray backgrounds and the diffusion of these annihilation products in the Earth’s atmosphere. Understanding and modeling the (non-WIMP-related) processes that produce cosmic rays is also a very active area of research.

Finally, we expect there to be high WIMP densities in the sun’s gravitational potential well. This means that we could conceivably hunt for WIMPs much closer to home and not have to worry about backgrounds from other sources in the galaxy. There is a catch, however. The sun is so incredibly dense that the mean free path of, say, a photon inside its center is only about a centimeter. Each particle that escapes to its surface can only do so after going through a random walk of many, many absorptions and re-emissions. On average, this can take as many as hundreds of thousands or even millions of years! Neutrinos are the sole exception: they interact so weakly with other standard model particles that for the most part they just zip straight through the sun with no problem. Searches for dark matter annihilations in the sun therefore focus on neutrino-producing processes.


Neutrinos themselves are difficult to detect, but fortunately we do have technologies that are capable of doing so.


Over the next decade or so, I predict that indirect detection will be a very hot topic in particle physics (and not just because I really like dark matter!) There are a number of clever experiments that have already produced some interesting results, and several more scheduled to be constructed over the next few years. Stay tuned, because there will be a Part II to this article that will look at some of these experiments in detail.


Isaac Asimov (1920 – 1992) “expressed a certain gladness at living in a century in which we finally got the basis of the universe straight”. Albert Einstein (1870 – 1955) claimed: “The most incomprehensible thing about the world is that it is comprehensible”. Indeed there is general consensus in science that not only is the universe comprehensible but is it mostly well described by our current models. However, Daniel Kahneman counters: “Our comforting conviction that the world makes sense rests on a secure foundation: our almost unlimited ability to ignore our ignorance”.

Well, that puts a rather different perspective on Asimov’s and Einstein’s claims.  So who is this person that is raining on our parade? Kahneman is a psychologist who won the 2002 Nobel Prize in economics for his development of prospect theory. A century ago everyone quoted Sigmund Freud (1856 – 1939) to show how modern they were. Today, Kahneman seems to have assumed that role.[1]

Kahneman’s Nobel Prize winning prospect theory, developed with Amos Tversky (1937 –1996), replaced expected utility theory. The latter assumed that people made economic choices based on the expected utility of the results, that is they would behave rationally. In contrast, Kahneman and company have shown that people are irrational in well-defined and predictable ways. For example, it is understood that the phrasing of a question can (irrationally) change how people answer, even if the meaning of the question is the same.

Kahneman’s book, Thinking, Fast and Slow, really should be required reading for everyone. It explains a lot of what goes on (gives the illusion of comprehension?) and provides practical tips for thinking rationally. For example, when I was on a visit in China, the merchants would hand me a calculator to type in what I would pay for a given item. Their response to the number I typed in was always the same: You’re joking, right?  Kahneman would explain that they were trying to remove the anchor set by the first number entered in the calculator. Anchoring is a common aspect of how we think.

Since, as Kahneman argues, we are inherently irrational one has to wonder about the general validity of the philosophic approach to knowledge; an approach based largely on rational argument. Science overcomes our inherent irrationality by constraining our rational arguments by frequent, independently-repeated observations.  Much as with project management, we tend to be irrationally overconfident of our ability to estimate resource requirements.  Estimates of project resource requirements not constrained by real world observations leads to the project being over budget and delivered past deadlines. Even Kahneman was not immune to this trap of being overly optimistic.

Kahneman’s cynicism has been echoed by others. For example, H.L. Mencken (1880 –1956) said:  “The most common of all follies is to believe passionately in the palpably not true. It is the chief occupation of mankind”. Are the cynics correct? Is our belief that the universe is comprehensible, and indeed mostly understood, a mirage based on our unlimited ability to ignore our ignorance? A brief look at history would tend to support that claim.  Surely the Buddha, after having achieved enlightenment, would have expressed relief and contentment for living in a century in which we finally got the basis of the universe straight. Saint Paul, in his letters, echoes the same claim that the universe is finally understood. René Descartes, with the method laid out in the Discourse on the Method and Principles of Philosophy, would have made the same claim.  And so it goes, almost everyone down through history believes that he/she comprehends how the universe works. I wonder if the cow in the barn has the same illusion. Unfortunately, each has a different understanding of what it means to comprehend how the universe works, so it is not even possible to compare the relative validity of the different claims. The unconscious mind fits all it knows into a coherent framework that gives the illusion of comprehension in terms of what it considers important. In doing so, it assumes that what you see is all there is.  Kahneman refers to this as WYSIATI (What You See Is All There Is).

To a large extent the understandability of the universe is mirage based on WYSIATI—our ignorance of our ignorance. We understand as much as we are aware of and capable of understanding; blissfully ignoring the rest. We do not know how quantum gravity works, if there is intelligent life elsewhere in the universe[2], or for that matter what the weather will be like next week. While our scientific models correctly describe much about the universe, they are, in the end, only models and leave much beyond their scope, including the ultimate nature of reality.

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[1] Let’s hope time is kinder to Kahneman than it was to Freud.

[2] Given our response to global warming, one can debate if there is intelligent life on earth.


Last week I was at a family reunion where I had the chance to talk to one of my more distant relations, Calvin. At 10 years old he seems to know more about particle physics and cosmology than most adults I know. We spent a couple of hours talking about the LHC, the big bang, trying to solve the energy crisis, and even the role of women in science . It turns out that Calvin had wanted to speak with a real scientist for quite a while, so I agreed to have a chat next time I was in the area. To be honest when I first agreed I was rolling my eyes at the prospect. I’ve had so many parents tell me about their children who are “into science” only to find out that they merely watch Mythbusters, or enjoyed reading a book about dinosaurs. However when I spoke to Calvin I found he had huge concentration and insight for someone of his age, and that he was enthusiastically curious about physics to the point where I felt he would never tire of the subject. Each question would lead to another, in the meantime he’d wait patiently for the answer, giving the discussion his full attention. He seemed content with the idea that we don’t have answers to some of these questions yet, or that it can take decades for someone to understand just one of the answers properly. The road to being a scientist is a long one and you’ve got to really want it and work hard to get there, and Calvin has what it takes.

Real scientists don't merely observe, they don't merely interact, they create.  (Child at the Science Museum London, studying an optical exhibit.  Nevit Dilmen 2008)

Real scientists don’t merely observe, they don’t merely interact, they create. (Child at the Science Museum London, studying an optical exhibit. Nevit Dilmen 2008)

Next month Calvin will start his final year in primary school and his teacher will be the same teacher I had at that age, Mark (a great name for a teacher!) From an early age I was fascinated by mathematics and computation, and without Mark I would not have discovered how much fun it was to play with numbers and shapes, something I’ve enjoyed ever since. Without his influence I probably would not have chosen to be a scientist. So once I found out Mark was going to teach Calvin I got in touch and told him that Calvin had the spark within him to get to university, but only if he had the right help along the way. In the area we are from, an industrial town in the North West of England, it is not usual for children to go to university, and there’s often strong peer pressure to not study hard. In this kind of environment it’s important to give encouragement to the children who can do well in academia. (Of course it would be better to change the environments in schools, but changing attitudes and cultures takes decades.)

All this made me think about my own experiences on the way to university, and I’m sure everyone had their own memories of the teachers who inspired them, and the frustrations of how much of high school focuses on learning facts instead of critical thinking. At primary school I had exhausted the mathematics textbooks very early on, under the guidance of Maggie Miller. From there Mark took over and taught me puzzles that went beyond anything I was taught in maths classes at high school. It was unfortunate that I was assigned a rather uninspiring maths teacher who would struggle to understand what I said at times, and it took the school about four years to organise classes that stretched its top students. This was mostly a matter of finding the resources than anything else; the school was caught in the middle of a regional educational crisis, and five small schools were fighting to stay open in a region that could only support four larger schools. One of the schools had to close and that would mean a huge upheaval for everyone. Challenging the brightest students became one of the ways that the school could show its worth and boost its statistics, so the pupils and school worked together to improve both their prospects. Since then the school has encouraged pupils to on extra subjects and exams if they want to, and I’m glad to stay that not only has it stayed open but it’s now going from strength to strength, and I’m glad to have played a very small part in that success.

By the time I was at college there was a whole new level of possibilities, as they had teams dedicated to helping students get to university, and some classes were arranged to fit around the few students that needed them, rather than the other way around. Some of the support still depended on individuals putting in extra effort though, including staff pulling strings to arrange a visit to Oxford where we met with tutors and professors who could give us practice interviews. I realised there was quite a coincidence, because one of the people who gave a practice interview, Bobbie Miller, was the son of Maggie Miller, one of my primary school teachers. At the same time one of my older and more dedicated tutors, Lance, had to take time off for ill health. He invited me and two others over to his house in the evenings for extra maths lessons, some of which went far beyond the scope of the syllabus and instead explored critical and creative mathematical thinking to give us a much deeper understanding of what we were studying. After one of my exams I heard the sad news that he’d passed away, but we knew that he was confident of our success and all three of us got the university positions we wanted, largely thanks to his help.

Unable to thank Lance, I went to visit Maggie Miller and thanked her. It was a surreal experience to go into her classroom and see how small the tables and chairs were, but it brings me back to the main point. Finding tomorrow’s scientists means identifying and encouraging them from an early age. The journey from primary school to university is long, hard, full of distractions and it’s easy to become unmotivated. It’s only through the help of dozens of people putting in extra effort that I got to where I am today, and I’m going to do what I can to help Calvin have the same opportunities. Looking back I am of course very grateful for this, but I also shudder to think of all the pupils who weren’t so lucky, and never got a chance to stretch their intellectual muscles. It doesn’t benefit anyone to let these children fall through the cracks of the educational system simply because it’s difficult to identify those who have the drive to be scientists, or because it’s hard work to give them the support they need. Once we link them up to the right people it’s a pleasure to give them the support they need.

There have always been scientists who have come from impoverished or unlikely backgrounds, from Michael Faraday to Sophie Germaine, who fought hard to find their own way, often educating themselves. Who knows how many more advances we would have today if more of their contemporaries had access to a university education? In many cases the knowledge of children quickly outpaces that of their parents, and since parents can’t be expected to find the right resources the support must come from the schools. On the other hand there are many parents who desperately want their children to do well at school and encourage them to excel in as many subjects as possible (hence my initial skepticism when I first heard Calvin was “into science”.) This means that we also need to be wary of imposing our own biases on children. I can talk about particle physics with Calvin all day, but if he wants to study acoustic engineering then nobody should try to dissuade him from that. Nobody has a crystal ball that can tell them what path Calvin will choose to take, not even Calvin, so he needs the freedom to explore his interests in his own way.

Michael Faraday, a self-taught physicist from a poor background, giving a Royal Society Christmas Lecture, perhaps inspiring aspiring scientists in the audience. (Alexander Blaikley)

Michael Faraday, a self-taught physicist from a poor background, giving a Royal Society Christmas Lecture, perhaps inspiring aspiring scientists in the audience. (Alexander Blaikley)

So how can we encourage young scientists-in-the-making? It can be a daunting task, but from my own experience the key is to find the right people to help encourage the child. Finding someone who can share their joy and experiences of science is not easy, and it may mean second or third hand acquaintances. At the same time, there are many resources online you can use. Give a child a computer, a book of mathematical puzzles, and some very simple programming knowledge, and see them find their own solutions. Take them to museums, labs, and universities where they can meet real scientists who love to talk about their work. The key is to engage them and allow them to take part in the process. They can watch all the documentaries and read all the science books in the world, but that’s a passive exercise, and being a scientist is never passive. If a child wants to be an actor it’s not enough to ask them to read plays, they want to perform them. You’ll soon find out if your child is interested in science because they won’t be able to stop themselves being interested. The drive to solve problems and seek answers is not something that can be taught or taken away, but it can be encouraged or frustrated. Encouraging these interests is a long term investment, but one that is well worth the effort in every sense. Hopefully Calvin will be one of tomorrow’s scientists. He certainly has the ability, but more importantly he has the drive, and that means given the right support he’ll do great things.

“Girls aren’t good at science!”, Calvin said. So I told him that some of the best physicists I know are women. I explained how Marie Curie migrated from Poland to France about a century ago to study the new science of radioactivity, how she faced fierce sexism, and despite all that still became the first person in history to win two Nobel Prizes, for chemistry and physics. If a 10 year old thinks that only men can be good scientists then either the message isn’t getting through properly, or as science advocates we’re failing in our role to make it accessible to everyone. We need to move beyond the images of Einstein, Feynman, Cox, and Tyson in the public image of science.


Coffee and Code (Part Deux)

Friday, August 29th, 2014

Further to my entry on the CERN Summer Student Webfest 2014 posted a few weeks ago (here), there is a short video about the event available to view HERE. Enjoy!



Do we live in a 2-D hologram?

Tuesday, August 26th, 2014

This Fermilab press release was published on Aug. 26, 2014.

A Fermilab scientist works on the laser beams at the heart of the Holometer experiment. The Holometer will use twin laser interferometers to test whether the universe is a 2-D hologram. Photo: Fermilab

A Fermilab scientist works on the laser beams at the heart of the Holometer experiment. The Holometer will use twin laser interferometers to test whether the universe is a 2-D hologram. Photo: Fermilab

A unique experiment at the U.S. Department of Energy’s Fermi National Accelerator Laboratory called the Holometer has started collecting data that will answer some mind-bending questions about our universe – including whether we live in a hologram.

Much like characters on a television show would not know that their seemingly 3-D world exists only on a 2-D screen, we could be clueless that our 3-D space is just an illusion. The information about everything in our universe could actually be encoded in tiny packets in two dimensions.

Get close enough to your TV screen and you’ll see pixels, small points of data that make a seamless image if you stand back. Scientists think that the universe’s information may be contained in the same way and that the natural “pixel size” of space is roughly 10 trillion trillion times smaller than an atom, a distance that physicists refer to as the Planck scale.

“We want to find out whether space-time is a quantum system just like matter is,” said Craig Hogan, director of Fermilab’s Center for Particle Astrophysics and the developer of the holographic noise theory. “If we see something, it will completely change ideas about space we’ve used for thousands of years.”

Quantum theory suggests that it is impossible to know both the exact location and the exact speed of subatomic particles. If space comes in 2-D bits with limited information about the precise location of objects, then space itself would fall under the same theory of uncertainty. The same way that matter continues to jiggle (as quantum waves) even when cooled to absolute zero, this digitized space should have built-in vibrations even in its lowest energy state.

Essentially, the experiment probes the limits of the universe’s ability to store information. If there is a set number of bits that tell you where something is, it eventually becomes impossible to find more specific information about the location – even in principle. The instrument testing these limits is Fermilab’s Holometer, or holographic interferometer, the most sensitive device ever created to measure the quantum jitter of space itself.

Now operating at full power, the Holometer uses a pair of interferometers placed close to one another. Each one sends a one-kilowatt laser beam (the equivalent of 200,000 laser pointers) at a beam splitter and down two perpendicular 40-meter arms. The light is then reflected back to the beam splitter where the two beams recombine, creating fluctuations in brightness if there is motion. Researchers analyze these fluctuations in the returning light to see if the beam splitter is moving in a certain way – being carried along on a jitter of space itself.

“Holographic noise” is expected to be present at all frequencies, but the scientists’ challenge is not to be fooled by other sources of vibrations. The Holometer is testing a frequency so high – millions of cycles per second – that motions of normal matter are not likely to cause problems. Rather, the dominant background noise is more often due to radio waves emitted by nearby electronics. The Holometer experiment is designed to identify and eliminate noise from such conventional sources.

“If we find a noise we can’t get rid of, we might be detecting something fundamental about nature – a noise that is intrinsic to space-time,” said Fermilab physicist Aaron Chou, lead scientist and project manager for the Holometer. “It’s an exciting moment for physics. A positive result will open a whole new avenue of questioning about how space works.”

The Holometer experiment, funded by the U.S. Department of Energy Office of Science and other sources, is expected to gather data over the coming year.

The Holometer team comprises 21 scientists and students from Fermilab, the Massachusetts Institute of Technology, the University of Chicago and the University of Michigan. For more information about the experiment, visit http://holometer.fnal.gov/.

Fermilab is America’s premier national laboratory for particle physics and accelerator research. A U.S. Department of Energy Office of Science laboratory, Fermilab is located near Chicago, Illinois, and operated under contract by the Fermi Research Alliance, LLC. Visit Fermilab’s website at www.fnal.gov and follow us on Twitter at @FermilabToday.

The DOE Office of Science is the single largest supporter of basic research in the physical sciences in the United States and is working to address some of the most pressing challenges of our time. For more information, please visit science.energy.gov.



This Fermilab press release came out on Aug. 18, 2014.

This image of the NGC 1398 galaxy was taken with the Dark Energy Camera. This galaxy lives in the Fornax cluster, roughly 65 million light-years from Earth. It is 135,000 light-years in diameter, just slightly larger than our own Milky Way galaxy, and contains more than 100 billion stars. Credit: Dark Energy Survey

This image of the NGC 1398 galaxy was taken with the Dark Energy Camera. This galaxy lives in the Fornax cluster, roughly 65 million light-years from Earth. It is 135,000 light-years in diameter, just slightly larger than our own Milky Way galaxy, and contains more than 100 billion stars. Credit: Dark Energy Survey

On Aug. 15, with its successful first season behind it, the Dark Energy Survey (DES) collaboration began its second year of mapping the southern sky in unprecedented detail. Using the Dark Energy Camera, a 570-megapixel imaging device built by the collaboration and mounted on the Victor M. Blanco Telescope in Chile, the survey’s five-year mission is to unravel the fundamental mystery of dark energy and its impact on our universe.

Along the way, the survey will take some of the most breathtaking pictures of the cosmos ever captured. The survey team has announced two ways the public can see the images from the first year.

Today, the Dark Energy Survey relaunched Dark Energy Detectives, its successful photo blog. Once every two weeks during the survey’s second season, a new image or video will be posted to www.darkenergydetectives.org, with an explanation provided by a scientist. During its first year, Dark Energy Detectives drew thousands of readers and followers, including more than 46,000 followers on its Tumblr site.

Starting on Sept. 1, the one-year anniversary of the start of the survey, the data collected by DES in its first season will become freely available to researchers worldwide. The data will be hosted by the National Optical Astronomy Observatory. The Blanco Telescope is hosted at the National Science Foundation’s Cerro Tololo Inter-American Observatory, the southern branch of NOAO.

In addition, the hundreds of thousands of individual images of the sky taken during the first season are being analyzed by thousands of computers at the National Center for Supercomputing Applications at the University of Illinois at Urbana-Champaign, Fermi National Accelerator Laboratory (Fermilab), and Lawrence Berkeley National Laboratory. The processed data will also be released in coming months.

Scientists on the survey will use these images to unravel the secrets of dark energy, the mysterious substance that makes up 70 percent of the mass and energy of the universe. Scientists have theorized that dark energy works in opposition to gravity and is responsible for the accelerating expansion of the universe.

“The first season was a resounding success, and we’ve already captured reams of data that will improve our understanding of the cosmos,” said DES Director Josh Frieman of the U.S. Department of Energy’s Fermi National Accelerator Laboratory and the University of Chicago. “We’re very excited to get the second season under way and continue to probe the mystery of dark energy.”

While results on the survey’s probe of dark energy are still more than a year away, a number of scientific results have already been published based on data collected with the Dark Energy Camera.

The first scientific paper based on Dark Energy Survey data was published in May by a team led by Ohio State University’s Peter Melchior. Using data that the survey team acquired while putting the Dark Energy Camera through its paces, they used a technique called gravitational lensing to determine the masses of clusters of galaxies.

In June, Dark Energy Survey researchers from the University of Portsmouth and their colleagues discovered a rare superluminous supernova in a galaxy 7.8 billion light years away. A group of students from the University of Michigan discovered five new objects in the Kuiper Belt, a region in the outer reaches of our solar system, including one that takes over a thousand years to orbit the Sun.

In February, Dark Energy Survey scientists used the camera to track a potentially hazardous asteroid that approached Earth. The data was used to show that the newly discovered Apollo-class asteroid 2014 BE63 would pose no risk.

Several more results are expected in the coming months, said Gary Bernstein of the University of Pennsylvania, project scientist for the Dark Energy Survey.

The Dark Energy Camera was built and tested at Fermilab. The camera can see light from more than 100,000 galaxies up to 8 billion light-years away in each crystal-clear digital snapshot.

“The Dark Energy Camera has proven to be a tremendous tool, not only for the Dark Energy Survey, but also for other important observations conducted year-round,” said Tom Diehl of Fermilab, operations scientist for the Dark Energy Survey. “The data collected during the survey’s first year — and its next four — will greatly improve our understanding of the way our universe works.”

The Dark Energy Survey Collaboration comprises more than 300 researchers from 25 institutions in six countries. For more information, visit http://www.darkenergysurvey.org.

Fermilab is America’s premier national laboratory for particle physics and accelerator research. A U.S. Department of Energy Office of Science laboratory, Fermilab is located near Chicago, Illinois, and operated under contract by the Fermi Research Alliance, LLC. Visit Fermilab’s website at www.fnal.gov and follow us on Twitter at @FermilabToday.

The DOE Office of Science is the single largest supporter of basic research in the physical sciences in the United States and is working to address some of the most pressing challenges of our time. For more information, please visit science.energy.gov.

The National Optical Astronomy Observatory (NOAO) is operated by the Association of Universities for Research in Astronomy (AURA), Inc., under cooperative agreement with the National Science Foundation.

The Particle Clicker team working late into the night.

The Particle Clicker team working late into the night.

This article was also published here on CERN’s website.

This weekend CERN hosted its third Summer Student Webfest, a three-day caffeine-fuelled coding event at which participants worked in small teams to build innovative projects using open-source web technologies.

There were a host of projects to inspire the public to learn about CERN and particle physics, and others to encourage people to explore web-based solutions to humanitarian disasters with CERN’s partner UNOSAT.

The event opened with a session of three-minute pitches: participants with project ideas tried to recruit team members with particular skills, from software development and design expertise to acumen in physics. Projects crystallised, merged or floundered as 14 pitches resulted in the formation of eight teams. Coffee was brewed and the hacking commenced…

Run Broton Run

Members of the Run Broton Run team help each other out at the CERN Summer Student Webfest 2014 (Image: James Doherty)

The weekend was interspersed with mentor-led workshops introducing participants to web technologies. CERN’s James Devine detailed how Arduino products can be used to build cosmic-ray detectors or monitor LHC operation, while developers from PyBossa provided an introduction to building crowdsourced citizen science projects on crowdcrafting.org. (See a full list of workshops).

After three days of hard work and two largely sleepless nights, the eight teams were faced with the daunting task of presenting their projects to a panel of experts, with a trip to the Mozilla Festival in London up for grabs for one member of the overall winning team. The teams presented a remarkable range of applications built from scratch in under 48 hours.

Students had the opportunity to with Ben Segal, an inductee of the Internet Hall of Fame.

Students had the opportunity to collaborate with Ben Segal (middle), inductee of the Internet Hall of Fame.

Prizes were awarded as follows:

Best Innovative Project: Terrain Elevation

A mobile phone application that accurately measures elevation. Designed as an economical method of choosing sites with a low risk of flooding for refugee camps.

Find out more.

Best Technology Project: Blindstore

A private query database with real potential for improving online privacy.

Find out more here.

Best Design Project: GeotagX and PyBossa

An easy-to-use crowdsourcing platform for NGOs to use in responding to humanitarian disasters.

Find out more here and here.

Best Educational Project: Run Broton Run

An educational 3D game that uses Kinect technology.

Find out more here.

Overall Winning Project: Particle Clicker

Particle Clicker is an elegantly designed detector-simulation game for web.

Play here.

“It’s been an amazing weekend where we’ve seen many impressive projects from different branches of technology,” says Kevin Dungs, captain of this year’s winning team. “I’m really looking forward to next year’s Webfest.”

Participants of the CERN Summer Student Webfest 2014 in the CERN Auditorium after three busy days' coding.

Participants of the CERN Summer Student Webfest 2014 in the CERN Auditorium after three busy days’ coding.

The CERN Summer Student Webfest was organised by François Grey, Ben Segal and SP Mohanty, and sponsored by the Citizen Cyberlab, Citizen Cyberscience Centre, Mozilla Foundation and The Port. Event mentors were from CERN, PyBossa and UNITAR/UNOSTAT. The judges were Antonella del Rosso (CERN Communications), Bilge Demirkoz (CERN Researcher) and Fons Rademakers (CTO of CERN Openlab).


The World’s Largest Detector?

Wednesday, August 13th, 2014

This morning, the @CERN_JOBS twitter feed tells us that the ATLAS experiment is the world’s largest detector:

CERN_JOBS Tweet Largest Detector

Weighing over 7,000 tons, 46 meters long, and 25 meters high, ATLAS is without a doubt the particle detector with the greatest volume ever built at a collider. I should point out, though, that my experiment, the Compact Muon Solenoid, is almost twice as heavy at over 12,000 tons:


CMS is smaller but heavier — which may be why we call it “compact.” What’s the difference? Well, it’s tough to tell from the pictures, in which CMS is open for tours and ATLAS is under construction, but the big difference is in the muon systems. CMS has short gaps between muon-detecting chambers, while ATLAS has a lot of space in order to allow muons to travel further and get a better measurement. That means that a lot of the volume of ATLAS is actually empty air! ATLAS folks often say that if you could somehow make it watertight, it would float; as a CMS member, I heartily recommend attempting to do this and seeing if it works. ;)

But the truth is that all this cross-LHC rivalry is small potatoes compared to another sort of detector: the ones that search for neutrinos require absolutely enormous volumes of material to get those ghostlike particles to interact even occasionally! For example, here’s IceCube:

"Icecube-architecture-diagram2009" by Nasa-verve - IceCube Science Team - Francis Halzen, Department of Physics, University of Wisconsin. Licensed under Creative Commons Attribution 3.0 via Wikimedia Commons - https://commons.wikimedia.org/wiki/File:Icecube-architecture-diagram2009.PNG#mediaviewer/File:Icecube-architecture-diagram2009.PNG

Most of its detecting volume is actually antarctic ice! Does that count? If it does, there may be a far bigger detector still. To follow that story, check out this 2012 post by Michael Duvernois: The Largest Neutrino Detector.


Watch Fermilab Deputy Director Joe Lykken in the latest entry in Huffington Post's "Talk Nerdy To Me" video series.

Watch Fermilab Deputy Director Joe Lykken in the latest entry in Huffington Post’s “Talk Nerdy To Me” video series.

What’s the smallest thing in the universe? Check out the latest entry in Huffington Post‘s Talk Nerdy to Me video series. Host Jacqueline Howard takes the viewer inside Fermilab and explains how scientists look for the smallest components that make up our world. Fermilab Deputy Director Joe Lykken talks about the new discoveries we hope to make in exploring the the subatomic realm.

View the 3-minute video at Huffington Post.