May 2007.Pdf

volume 04 | issue 04 | may 07

symmetryA joint Fermilab/SLAC publication

On the cover Roz Chast is best known for her cartoons in The New Yorker, more than 800 of which have appeared since 1978. But she’s no stranger to the sciences, having published in both The Sciences and Scientiﬁc American. She has written and illustrated several books, most recently Theories of Everything: Selected, Collected, and Health-Inspected Cartoons 1978–2006, and collaborated with Steve Martin on a children’s book that is scheduled to come out in October.

Ofﬁce of Science U.S. Department of Energy contents 2 Editorial: 3 Commentary: 4 Signal to Background A Public Hunger for Physics Sherry Yennello Say it in Russian; a quick how-to; The general public seems to Whether scientiﬁc meetings a zappy show; sports cars and want particle physics as part of provide childcare is much more cavities; radioactive people; farm- their intellectual, cultural, and than a matter of convenience. family reunion; tracking dark personal lives. energy; name that particle; letters

10 The Search for Dark 16 The Great String Debate 22 When the New Energy When Brian Greene and Neighbor’s a Giant What is this stuff that fills the Lawrence Krauss tangle over At one potential site for the vacuum of space, accelerates string theory, wisecracks fly. International Linear Collider, the expansion of the universe, people in the community are and accounts for 70 percent of getting to know the project everything? More than two dozen years in advance. experiments aim to find out.

28 Day in the Life: 30 Gallery: 32 Essay: Katie and Adam Yurkewicz Ken McMullen Launched into Science In the move from Fermilab to He calls his latest work a “very “Reading about science was not CERN, a $10 globe, 100 plastic radical new form of cinema” quite enough. I needed to get cookie cutters, and a large col- that mingles high-energy phys- up close and personal with the lection of refrigerator magnets ics and astrophysics with tid- scientists and their heroic are deemed worthy of shipping bits of philosophy and poetry. experiments.”—Pierre R. Schwob 4400 miles.

ibc Logbook: bc Explain it in 60 Seconds: The SLAC Bluebook String Theory A 1169-page treatise documents String theory proposes that the the development and design fundamental constituents of of the two-mile-long accelerator the universe are one-dimensional operated by Stanford University. “strings” rather than point-like particles. from the editor

A public hunger for physics Does the public care about particle physics? In this issue of symmetry we read about a few cases that hint the answer is yes. A debate about string theory in Washington, DC, in March, attracted a sold- out crowd of 600 people. The two-hour debate and discussion between Brian Greene and Lawrence Krauss, moderated by Michael Turner, com- manded a ticket price of $25. For a few hours of entertainment, these 600 fans were prepared to pay more than twice the going rate for the latest Hollywood fare. A few disappointed aficionados hovered around the entrance trying to buy tickets, but there were none to be had. Meanwhile, Fermilab asked nearby residents to volunteer for its community task force. More than 80 people applied to serve on the task force, which meets monthly to learn about Fermilab’s plans and advise the physics laboratory on how it can best work with its neighbors. To gain one of the 25 positions on the task force, volunteers had to go through a demanding application process that even included interviews. These people saw that participating was worth the investment in effort and commitment. Many people have a stake in physics, because of its cultural influence or because of how it affects their communities. This issue of symmetry is the 25th since we launched in October 2004. The feedback we have received consistently is that readers most enjoy Photo: Reidar Hahn, Fermilab the magazine when it is showing how physics is simply another part of their own personal universes. They are enthused by stories of how people achieve scientific discoveries. They are entertained by what scientists do outside the laboratory. They want to get their hands on the science- related artworks we showcase. They love hearing what physics outsiders think of the physics community. For this issue, we asked The New Yorker cartoonist Roz Chast to interpret particle physics for our cover and for a feature story on searches for dark energy (see page 10). Chast reacted to particle physics in the way that many non-physicists do: by seeing science as part of an attempt to answer the fundamental questions that all curious people ask themselves. The public does want physics and we are grateful that we are part of an effort to show how it enriches lives intellectually, culturally, and personally. David Harris, Editor-in-chief

Symmetry Editor-in-Chief Publishers Print Design and Production PO Box 500 David Harris Neil Calder, SLAC Sandbox Studio MS 206 650 926 8580 Judy Jackson, FNAL Chicago, Illinois Batavia Illinois 60510 USA Deputy Editor Contributing Editors Art Director Glennda Chui Roberta Antolini, LNGS Michael Branigan 630 840 3351 telephone Peter Barratt, STFC 630 840 8780 fax Executive Editor Romeo Bassoli, INFN Designers www.symmetrymagazine.org Mike Perricone Stefano Bianco, LNF Aaron Grant Anilou Price [email protected] Managing Editor Kandice Carter, JLab Kurt Riesselmann Reid Edwards, LBNL Web Design and Production (c) 2007 symmetry All rights Catherine Foster, ANL Xeno Media reserved Staff Writers James Gillies, CERN Hinsdale, Illinois Elizabeth Clements Silvia Giromini, LNF symmetry (ISSN 1931-8367)

Heather Rock Woods Youhei Morita, KEK Web Architect symmetry | volume 04 issue may 07 is published 10 times per year Rhianna Wisniewski Marcello Pavan, TRIUMF Kevin Munday by Fermi National Accelerator Mona Rowe, BNL Laboratory and Stanford Copy Editor Perrine Royole-Degieux, IN2P3 Web Design Linear Accelerator Center, Melinda Lee Yuri Ryabov, IHEP Protvino Karen Acklin funded by the US Department Yves Sacquin, CEA-Saclay Alex Tarasiewicz of Energy Ofﬁce of Science. Interns Kate Raiford Boris Starchenko, JINR Web Programmer María José Viñas Maury Tigner, LEPP Mike Acklin Marcus Woo Ute Wilhelmsen, DESY Tongzhou Xu, IHEP Beijing Photographic Services Gabby Zegers, NIKHEF Fermilab Visual Media symmetry Services

2 commentary: sherry yennello

earlier–whether as graduate students, postdocs, or junior faculty. Being a graduate student is not a lucrative situation–it wasn’t when I was a student and it isn’t now. Add to that the financial burden of childcare, which grad students often need beyond normal hours, and of health insurance Photo courtesy of Sherry Yennello for dependents, which is often not covered under graduate student policies or covered only at a significant premium, and you have a very financially strapped individual. If there is no afford- Is there room in able childcare available at meetings, you have the high-energy just priced that critical activity out of the reach of many female students with children. physics community This challenge is not unique to high-energy for families? physics, but it is certainly significant in a field “Bob, you know my new graduate student asked where the percentage of women in committed me the other day why there were no women relationships with other professionals is much speaking at this conference. I told her women higher than for men. A 1998 survey by the often made choices that are inconsistent with American Institute of Physics revealed that 43% a career in physics. She asked me what I meant, of its women members are married to other and I told her, ‘Well, for example, like having physicists while only 6% of married male physi- kids.’ I once had a promising graduate student cists have a physicist spouse. Other fields have named Alice, but she decided she wanted a risen to the challenge by awarding childcare family. When I thought she should give a talk on grants or providing sponsored or subsidized child- her thesis work, she said she couldn’t go to the care at meetings, opening a family room nearby, meeting without some assistance for childcare. or setting up bulletin boards where families can Since the data were so exciting, I sent James, work out shared childcare arrangements. Some who worked on the project with her, to give the universities also have started to provide childcare talk. At the meeting, James met Dr. Famous, who assistance so graduate students or junior faculty had already been talking to Alice about a postdoc can attend meetings. The American Physical position; James got the position instead. James Society’s Committee on the Status of Women in now has tenure on the faculty of Prestigious Physics has proposed that childcare grants be University. Alice eventually became an instructor made available for the March and April meetings. at a teaching school. Not going to that meeting Smart women will make smart choices. Some probably cost Alice her career.” will decide the allure of uncovering nature’s hid- “But, Sam, that is better than what Sara did. den secrets is worth the sacrifice, and become When I offered to send her to a meeting, she existence proofs that women can do physics. brought the kid. Sara went to very few talks, and But others may decide that the cost of belonging when she did, the kid was there distracting her to this club is too great. And the loss will be ours. and everyone else. Needless to say, she didn’t get Wouldn’t we all prefer the following conversation? a job, and I wasted my money supporting her.” “George, that was a great talk your student Do you want our field to be responsible for Jennifer gave yesterday. I was afraid she might such a conversation? We have a choice to either not be able to come to the meeting because of leave things the way they are and claim there the baby. But then she told me about the Kids are no women to hire, or we can think about ways Club, and how childcare was provided at the to enable women to succeed and become inte- meeting. I know I’ve enjoyed having some of my grated in the field. The case for childcare at colleagues’ kids around for evening events, but

meetings is simple: In a field as tightly knit as I hadn’t realized that it was such an organized symmetry | volume 04 issue may 07 high-energy physics, being at meetings to pres- program where they take the kids to parks and ent your work, hear about others’ progress, and children’s museums. I suppose this might be network with people who are established in the why we have so many more top-notch women in field is critical to advancing one’s career. Further- the field these days.” more, it is unrealistic to tell female students that they must wait until they are tenured professors Sherry J. Yennello is a professor of chemistry who studies heavy- ion collisions. She is the proud mother of a 6-year-old daughter to have children; biologically, that might be too conceived after she had tenure at Texas A&M University. late. So, we must enable them to have a career trajectory that is compatible with having children

3 farm-family reunion;tracking darkenergy;namethatparticle;letters Say itinRussian;aquick how-to;azappyshow;sportydesign;radioactivepeople; signal to background is one of the many who have have who many the of one is Russians. the to amusing—especially proved as it moves through the tunnel, bend of the Tevatron’s beamline crucial monitors displaying the fun seemevenbetter.” midnight shift,which madethe also mentionthatitwasthe should “I college. in Russian Edstrom, whostudiedsome says idea,” fun a like seemed it time, the at department Tevatron the in Russians Russian. the old ones with fresh ones. In replace to decided Edstrom labels, decades-old off peeling while cleaning equipment and ator on the owl shift. One night, working as an accelerator oper while awake stay to Room Control Main Fermilab the tidies routinely Edstrom Chip Peel andstick Vsevolod “Seva” Kamerdzhiev two mark which labels, The of number the “Considering

email,” to “How to organize organize to “How to email,” ﬂawless a write to “How from ranging explanations 60-second provides that site How-To, Web a One-Minute for segments audio vided pro have Winick Herman cist physi SLAC and Murayama Hitoshi physicist Lab Berkeley Wait justaminute Kate Raiford says. he welcome,” being of feeling nice a give labels ates thegesture.“The Russian thus changing their meanings. ings of the words were incorrect, ones to make as only the end grammatical errorswereeasy this,” Kamerdzhievsays.The wouldn’t beusedinacaselike “The words do exist—they just simply “horizontal” and “vertical.” and “this is vertical,” instead of had written “this is horizontal” grammar. On the labels Edstrom creative Edstrom’s enjoyed Still, Kamerdzhievappreci 4

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X-rays areaubiquitous toolin ofﬁces.And anddental tals that we are familiar with in hospi than the normal X-ray machines sources aresomuch greater of X-ray lasersandotherX-ray ence becausetheintensity amounts toarevolutioninsci what achieved “Wehave says: Lasers” (program #113), Winick with each other.” together, and how they interact put are they how of, made we know about what things are it really describes everything 20th-century science, because of thebiggestachievements in one it’s say would I universe. around us and everything in the everything describing with theory physicists have come up he says is “probably the best which #117), (program Model” Standard the Understand smoking.” stop to “How to clean-up,” river a In “How to Understand X-ray to “How tells Murayama

Photo: Reidar Hahn, Fermilab

symmetry | volume 04 | issue 04 | may 07 Photo: Reidar Hahn, Fermilab has opened up entirely new entirely up opened has intensity in increase the so so manybranches ofresearch; brother, Andrew, watched wide- phone! cell your off turn and back behindtheropes, Stay ger: More than one million volts! pents from the top of the thing. ser fiery like writhing bolts, and crackle of artificial lightning giant Tesla coil stands out. and power-tool drag races, the human cupcakes, battling robots, story nose-picking machine, Even in the company of a two- Tesla inparadise Mike Perricone www.oneminutehowto.com. loaded from: scientific areas.” Paulina Shearerandher Maybe it’s the hint of dan buzz loud the it’s Maybe The programs can be down

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ing electrical arcs (Look folks, ward to do battle with the ﬂash a clunky metal suit, came for in enclosed safely volunteer, a eyed, hands over their ears, as in the world where you get paid having fun, that there are jobs we’re see them let to also and opportunities, tell themabout “WeCenter (SLAC). useitto Accelerator Linear Stanford works onexperiments atthe who Schalk, meat,” says some present actually to physics real enough It’s students. of tocatch theattention tainment work. accelerators particle how to galaxies and fromatoms span everything demonstrations Their science. to lurekidsintotheworldof it using year, a times 10 about haul the Tesla coil to schools Physics, Particle of Institute Cruz of physicsattheSanta Sadrozinski, adjunctprofessors yourself technology projects. a magazine devoted to May by the publishers of Mateo, California, put on in late annual Maker Faire in San Paulina said, “but kind of freaky.” he’s safe! Give him a hand!). enter enough just is “This Terry andHartmut Schalk The scene was the second “It was cool,” six-year-old 5 do-it- Make - - ,

candy everywhere. I was drooling paradise,” Schalk says. “It was eye tron fromscratch. build aworking1.5MeVcyclo friends three helped graduate, under an as who, guy a for on thecake—theperfect venue for theirkids. or ask about summer programs school their Tesla to the coil SLAC tours, ﬁnd out how to bring demonstrations tosignupfor lot ofpeoplecameupafterthe A success. big a was Faire Maker the at stint two-day the to get hitbyit.” hit byit,butIwouldn’tbeafraid gerous: “I’d just as soon not get the coilitselfisnotthatdan to do what you ﬁnd interesting.” Glennda Chui that make things out of sugar.” tus, and all over the all over the LEGO train appara “This whole show was a geek’s icing was itself Faire The standpoint, Schalk’s From Despite the theatrics, he adds, 3 D printers - -

Photos courtesy of Jason Chen, Gizmodo.com

symmetry | volume 04 | issue 04 | may 07 signal to background They hope the process will will process the hope They a nine-cell cavity from niobium. Hamburg, has used it to create German national laboratory in DESY, the from team small a Now cars. sports high-end for shapes complicated into metal—mostly aluminum alloys— auto industry to mold sheets of Hydroforming is used in the for cavities Sports cartreatment Illustration: SandboxStudio team hadalotofsupportand material scientistatDESY. The way,” saysWaldemar Singer, a ity tubes, simulated every eventual procedures, usedallsortsof performance. cavity hinder can that flaws welding of risk the reducing thickness andonlytwoseams, uniform of walls has product shape of the cavity. The finished the in mold a into metal the pressure inside the tube, forcing water the increases system the brim with water. A hydraulic to filled it’s Then cells. bulging cavity’s the between parts grooved toproducethenarrow is tube the First diameter. in millimeters 150 tube niobium a the way they’re put together. is determined by their shape and electrons pass through them, cavities, measured by the way collider. The performance of the that accelerateparticlesina ate theelectromagnetic fields Collider. Linear International the for needed cavities 16,000 building for handy in come untilwefoundtheperfect “We have tried many different with starts Hydroforming Radiofrequency cavities cre

for NuclearResearch. Other help fromtheRussianInstitute How sensitiveisthemeasure gaskets, and other components. plasticknobs, tures ofEXO’s theradiationsigna cataloging his teamhavebeencarefully radiation, AndreasPiepkeand of thedetector itself. rounding rock andfrompieces of naturalradiationfromsur chatter constant the with tend cosmic rays,itstillhastocon from it protects location deep the mass of the neutrino. ers hope will help them pin down double beta decay that research decay known as the neutrinoless search forsignsofanuclear Mexico saltmine.There itwill mile belowgroundinaNew halfa destined forinstallation Enriched Xenon Observatory), of an experiment called EXO (the naturally emittedbypeople. be shieldedfromtheradiation to needs measurements of set site istrue.There, asensitive Tuscaloosa, however, theoppo the at laboratory a For activity. protect labworkersfromradio to need a indicate normally Lead bricks and radiation gloves Those pesky humans Global DesignEffort Barbara Warmbein, ILC facility. Fermilab is planningasimilar and machine hydroforming a isbuilding act; Japan’sKEK the on in getting also are labs To measure this background experiment’s the While The measurements are part University of Alabama in in Alabama of University 6

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been identiﬁeditwillbeeasier have radiation background ing testing. to shieldthecomponentsdur signatures ofleadbricks used account forthefaintradiation to had also team The gram. a millionbecquerelsperkilo about waste radioactive level becquerels, andtypicallow- detector contains about 30,000 smoke household a ison, sure ofradioactivity. Incompar mea a as curie the replaced has that unit querels—a bec 7000 about that’s adult, typical a For bodies. own their by off given radiation from ers ment equipment? The research are all farmers. We’re older older We’re farmers. all are “We says. Baumann friends,” old see to year every back come “I community. farming decades-old their celebrate to people 100 nearly attracted Picnic Farmers’ Fermilab nity survives. down, but the farming commu ﬁelds and barns have been torn grasses have overtaken the construction of Fermilab. Today, years ago to make way for the 40 relocated farmers, other 55 like Baumann, barn. red sits Leonard Baumann’s rickety secluded from most of Fermilab, boundary, site the inside Just Farmers’ picnic Alabama Mike Wofsey, Universityof noise. the from signals valid the separate to hadtoshieldtheapparatus Once all the sources of of sources the all Once In May, the 10th annual annual 10th the May, In ------

symmetry | volume 04 | issue 04 | may 07 conference on Weak and Electromagnetic Interactions in Nuclei (WEIN 98). Since then, the number of papers has increased dramatically, often doubling or even tripling from year to year. In 2006, the number of papers with “dark energy” in the title exceeded 300 (see graphic), about 20 percent more than those published in 2005. Dark energy has captured the imaginations of physicists working in a variety of subfields represented in the spires database. While the majority of than rocks.” Baumann will be barns once sat. Baumann’s dark-energy-titled papers, 85 in two weeks. barn is still standing, although it about three quarters, are sub- Inside Fermilab’s Kuhn is showing signs of its nearly mitted to the spires astro- Barn, one of several barns still 100 years and may have to be physics phenomenology (astro- in use, visitors were treated torn down for reasons of safety. ph) e-print archive, 1 in 10 can to a spread of treats, including Kate Raiford be found in gravity-quantum Photo: Reidar Hahn, Fermilab a farm-scene cake complete cosmology (gr-qc), another 10 with a barn and rows of crops. A tale of dark energy percent in high-energy physics Fermilab’s Bob Lootens, who In the 1990s, astronomical theory (hep-th) and 6 percent used to live on one of the farms, observations revealed that the in high-energy physics phenom- drove a group of about 10 par- expansion of the universe is enology (hep-ph). Even the tygoers around the lab. “I’m accelerating. Not knowing what condensed matter physics (cond- going to take you down mem- causes this acceleration, scien- mat) archive contains a paper ory lane,” he said as the bus tists began to attribute the with “dark energy” in its title. turned onto Holter Road inside phenomenon to some unknown Today, there are more than the Tevatron’s main ring. source of energy, coined 1000 of these papers on dark Prairie burns have thinned “dark energy” by astrophysicist energy. A look at the references out the forest, making it look as Michael Turner. these papers make to other it did in the past; even the same According to the spires scientific studies reveals what gravel roads are there. “It’s like database, the first three papers might be the most influential a time capsule,” Lootens says. to contain the words “dark paper in dark energy research: For the farming community, energy” in the title were pub- about one-third of all papers cite the Farmers’ Picnic is a chance lished in 1998: a Physical “Cosmological Consequences of to reconnect with those who Review D article by Turner and a Rolling Homogeneous Scalar used to live here. Baumann looks Dragan Huterer; an article by Field,” published by Bharat up his friends every once in Turner summarizing his talk at Ratra and P.J.E. Peebles of a while, and depended on them the Stromlo Symposium; and Princeton University (Phys. Rev. when he had open heart sur- a Lawrence Krauss article in D 37:3406, 1988). gery. “They were there to sup- the proceedings of the 1998 Heath O’Connell, Fermilab port me,” he said. Flanked by relatives, 303 300 Baumann pointed out people Scientific papers 267 he knew from the pre-Fermilab with the words “dark energy” in 250 days, including a 96-year-old 210 woman for whom he had baled the title 200

hay when he was younger. A symmetry | volume 04 issue may 07 former babysitter, Janet L. Mish, 134 150 also remembered life in the 95 100 rural community. “I babysat for Number of papers a lot of the people who lived 48 50 on these farms. I miss these 15 3 4 people,” she said. 0 SPIRES Some from the farming 98 99 00 01 02 03 04 05 06

community can recognize Year Source: patches of grass where their

7 signal to background CALL TO ACTION! The symmetry challenge: Name that particle Flerbs? Marteenies?? Tom, Dick, and Harry??? Cartoonist Roz Chast has busted the ﬁeld of particle physics wide open with her pioneering cover for this issue of symmetry. We say it’s about time: Why limit ourselves to the same old list of particles that have actually been discovered, or at least properly theorized? So here’s the challenge: Invent an elementary particle and tell us what it does in 30 words or less. A drawing would be nice, but not mandatory. Send your entry to [email protected] with subject line “Contest” or mail it to the address on page 2. The winner will receive an autographed copy of Roz Chast’s cover and a place of honor for their entry in an upcoming issue.

Letters

Nice ice Left: The roof of the car pictured in the March 07 A recent article by scientists in Leeds and Oslo issue of symmetry, courtesy featured in CERN’s “Picked Up for You” of Terry Anderson, SLAC. might have an answer to Terry Anderson’s ice-related question in March’s symmetry. Terry’s frost picture bears a striking resem- blance to the patterns formed in draining thin-ﬁlm suspensions. I invite readers to take a look at the article at: http://dx.doi.org/10.1021/la063282a Heath O’Connell, Fermilab

The little article about frost on the roof of a Honda reminded me of the photo I took of frost on my step-daughter’s 1994 Honda Accord roof. I don’t recall the details, except that I thought it was beautiful. Here’s the photo. Thanks for a great magazine. David Frye, Denton, NE

Aspirins in times of war I know of the use of aspirins as water detectors (Apr 07) from my year and a half (June 70– Jan 72) in the US Army in the Republic of South Vietnam on the receiving end. I heard from people who had been there in the late 1960s that it had been used then as well. Perhaps the

engineers and technicians using aspirins to detect water seeping into accelerators had been symmetry | volume 04 issue may 07 or knew someone who had been in Vietnam. Because American counter-battery artillery ﬁre was so effective, the North Vietnam army did not want to be around when the rocket launched. Therefore, they would bring rockets down from North Vietnam and gather launching supplies locally: bamboo to make launch platforms; old batteries, wire, and aspirins to launch the rockets. Crossed wires separated by an aspirin were used as a switch. It rains often in South Vietnam in the monsoon season and even in the dry season there is enough humidity close to the ground to break down an aspirin in a few days. Randolph Herber, Fermilab

8 Black holes for beginners I read the nice article by Jennifer Ouellette “Beginner’s mind” in the March 2007 edition with great interest. Based on current information I do not understand why the production of a mini black hole produced at the Tevatron or LHC, which is mentioned as a very well chosen example by Ouellette, does not pose any safety risk. Can the possibility be ignored in the safety planning of these labs? I hold a PhD in particle astrophysics and read all original technical literature pertaining to this risk that I could ﬁnd (including the safety reports on this subject prepared at BNL and CERN in 2000 and 2003). To some of my friends without a physics background the whole issue must appear even more threatening. A recent made-for-television movie (The Black Hole, USA, 2006) about a collider catastrophe might contribute to public concerns. May I respectfully ask whether the particle physics community plans to rise to Ouellette’s challenge and commission some of its members to explain the reasons for the absence of the potential risk mentioned by Ouellette to an audience with a “Beginner’s mind”? Rainer Plaga, Bonn, Germany

The editors respond: CERN has a document addressing this topic, available on its public Web site at: http://public.web.cern.ch/Public/Content/Chapters/AboutCERN/CERNFuture/ LHCSafe/LHCSafe-en.html or http://tinyurl.com/2ya8pk

More famous undercited Cooking up Improvisation physicists The article (Apr 07) on improvisation in The numbers on citations and all listed by experimental physics was a fascinating one. Heath O’Connell (Mar 07) are exceedingly Along the same lines, I heard that at interesting! The general phenomenon has Cornell (I think), and probably at least one been known to people working in sciento- other accelerator, Revereware—copper- metrics for many decades, and is called bottomed steel cookware—was used to “incorporation.” I also rediscovered it, about avoid having to make copper to steel 20 years ago, in connection with astro- welds. Instead a hole was cut in the cop- nomical entities like the Schwarzschild per bottom of the cookware, and that solution, Weber bars, and von Zeipel’s was welded to copper pipe. Then the steel theorem. Not then knowing that it was top was welded to steel. a well-established concept, I coined the Lance Dixon, SLAC name “second order Mossbauer effect” (meaning that many folks used and use Mossbauer spectroscopy, but rather few cite him). Virginia Trimble, Past Chair, APS Forum on History of Physics

Past and future by reflecting on the fact that established theo- I’ve observed an important relationship between ries (past) conflicted with some experimental David Harris’ intro “Appreciating Successes” results. The impressive success of general rela- and Ray Orbach’s “Focus on the Future” in the tivity could not have been possible without March issue of symmetry. appreciating the success of Newtonian Both theorists and experimental physicists mechanics. need to retrace the past of their fields so Grand Unified Theories can also record as to ensure a promising future. Physicists, impressive successes if physicists cultivate symmetry | volume 04 issue may 07 especially theorists, have advanced their the culture of reflecting deeply on past respective fields by using different approaches, successes and fervently focusing on future but one thing is common to them all, appre- possibilities. ciating successes and focusing on the future; Ayodele Adebayo, Obafemi Awolowo the prediction of existence of neutrino (future) University, Nigeria

Letters can be submitted via [email protected]

What is this stuff that ﬁlls the vacuum of space, accelerates the expansion of the universe, and accounts for 70 percent of everything? More than two dozen experiments aim to ﬁnd out.

The universe is expanding faster and faster, but no one knows why. Now researchers are proposing a host of ambitious experiments to measure dark energy, the mysterious phenomenon that is thought to be driving the acceleration. They’ll be looking for clues in exploding stars; ancient, frozen sound waves; and the way massive objects in space bend and distort light. Scientists want to know precisely how much dark energy there is, and whether its effects evolve over time. To that end, there are nearly 30 experiments proposed or under way, according to the Dark Energy Task Force, a committee established by the US National Science Foundation, the US Department of Energy, and NASA. “Each of these projects on the table has the potential of dramatically advancing the field,” says cosmologist Andreas Albrecht of the University of California, Davis. “It’s not like we have to wait for new technology or a new invention. We can go out and do this, and it’s really exciting—it’s a great place to be.” A mind-boggling discovery Until about 10 years ago, scientists thought the expansion of the universe that began with the big bang was slowing down. Then observations of distant, exploding stars known as Type Ia supernovae revealed the existence of dark energy, shocking astronomers. “It’s causing the expansion of the universe to accelerate—that’s a mind- boggling discovery,” says Roger Blandford, an astrophysicist at the Kavli Institute for Particle Astrophysics and Cosmology (KIPAC) at Stanford University and the Stanford Linear Accelerator Center. Meanwhile, information embedded in the cosmic microwave background, which contains the echoes of the big bang, showed that the universe must hold a certain amount of energy and matter. The sum total of all the visible stars and galaxies, however, along with the dark matter that is not directly observable, makes up only about 30% of this expected amount. Dark energy must make up the majority of the universe, accounting for 70% of its contents. Physicists have several ideas of what dark energy could be, one of which harks back to what Einstein reportedly considered his biggest blunder— the cosmological constant. Originally a term Einstein inserted in his equations to force them to reflect the prevailing notion of a static universe, the modern cosmological constant is a pervasive energy that stays the same throughout space and time. Blandford calls it a pristine energy field. “It almost raises metaphysical questions as to why it should be so,” he says. Also called vacuum energy, it is the energy of empty space, possibly caused by quantum effects. On the other hand, dark energy might be something more complicated— an exotic energy field called quintessence that varies over space and time. Alternatively, dark energy may not be energy at all, but the result of gravity behaving oddly at the vast scale of the growing universe. If this is true, physicists might need to modify one of the hallmarks of modern physics, Einstein’s general theory of relativity.

A host of experiments Some of the proposed hunts for dark energy could start bringing in new data as soon as 2010. For instance, the Dark Energy Survey (DES), will scan the sky from a new camera on the existing four-meter Blanco telescope at the Cerro Tololo Inter-American Observatory in Chile. Although researchers are planning more powerful telescopes to be built over the next decade, DES is particularly important because it can start collecting data in just a couple of years. “At the time it starts running, it’ll be the most powerful dark energy experiment,” says James Annis, an experimental astrophysicist at Fermilab who is involved in the project. “The time we’re running on is on the scale of a PhD thesis, and not a professor’s career.” From DES, scientists hope to develop new data-analysis techniques that can improve the next stage of experiments. “We’re a stepping stone,” Annis says. “We’ll keep pushing science forward while we wait for bigger projects to come.”

Cosmic yardsticks One way to measure how the universe has expanded over time is to observe Type Ia supernovae. They are like lampposts lighting the path of the cosmological past, and provide astronomers with the most well-established technique for understanding how the universe has been growing. Type Ia supernovae are stars that happen to explode with the same energy every time, making them so-called standard candles. By comparing their observed and theoretical brightnesses, astronomers can deduce how far away they are. The proposed Dark Energy Space Telescope, or Destiny, would look for thousands of new supernovae. It’s one of three candidates for the Joint Dark Energy Mission (JDEM) proposed by NASA and the Department of Energy. Another candidate, the Advanced Dark Energy Physics Telescope, or ADEPT, would also observe supernovae, but its main objective would be to measure primordial rumblings called baryonic acoustic oscillations. Around 300,000 years after the big bang, the universe was a soup of ions reverberating with sound waves. Once the soup expanded and its contents separated into neutral atoms, the signature of these sound waves froze into the cosmic microwave background and into the accumulating matter that eventually coalesced into stars and galaxies. By sifting through the microwave background and the distribution of galaxies, astronomers could ﬁnd the imprint of these ancient sound waves; their size would provide another measure of cosmological distances.

Gravity and growth A second line of investigation is to analyze the growth of structure in the universe. As the universe evolved, gravity drew small clumps of matter together, eventually forming the stars and galaxies seen today. Because dark energy opposes gravity, it would stunt the growth of the universe, and in doing so, leave clues about its properties. By directly measuring the structure of matter on large scales, scientists hope to ﬁnd out whether dark energy is actually a form of energy or the result of an incomplete understanding of gravity. Some of these studies will take advantage of a phenomenon called gravitational lensing, caused when matter bends light. There are two types of lensing—strong and weak. With strong lensing, a galaxy or another massive object lying in front of a source of light can bend that background light completely out of shape, sometimes making multiple images of it. In weak lensing, masses that are spread out more thinly create subtle distortions that require statistical analyses to detect. The amount of distor- tion indicates how much dark matter there is, giving researchers a way to map the matter in the universe and ﬁnd out how its structure changed over time. Because it can scan vast swaths of the sky, the proposed Large Synoptic Survey Telescope (LSST) would be particularly adept at measuring weak lensing effects. A bigger version of DES, the LSST would be an 8.4-meter ground-based telescope on Cerro Pachon in Chile. Armed with a powerful camera, it would take thousands of pictures of every region of space, covering half the sky in just a few days. Another way to map the distribution of matter is to take a census of groups of galaxies bound by gravity. Galaxy clusters are the largest structures in the universe, and astronomers can detect these behemoths in various ways, including X-ray and optical observations. The Constellation-X Observatory, a proposed space mission, would consist of four telescopes on one spacecraft. About 100 times more powerful than current telescopes, such as the Chandra X-ray Observatory, it would investigate how dark energy has shaped the clustering of galaxies and driven the acceleration of the universe.

Multiple approaches Researchers say it will take a combination of all four approaches—observing supernovae, frozen sound waves, gravitational lensing, and galaxy clusters— to resolve the dark energy conundrum. “The most exciting part of this field isn’t just dark energy, but the con- vergence of these tests,” says Steven Kahn, a KIPAC astrophysicist. The combination of independent techniques would not only build confidence in the results, but also give researchers a better understanding of the techniques themselves, cutting down on experimental uncertainties. This would lead to more precise measurements in the future and a deeper interpretation of the data. Indeed, many proposals employ more than one approach. For instance, the third candidate for JDEM, called the Supernova/Acceleration Probe, is designed to observe supernovae deep in the sky, but would also observe weak lensing effects and frozen sound waves. The Square Kilometer Array, a proposed radio telescope, would survey both frozen sound waves and galaxy clusters. In one of its key findings, the Dark Energy Task Force concluded that this diversity in approach is essential. But with so many proposals on the table and limited funds, deciding which experiment to pursue is a difficult challenge.

The path to the future As important as the dark energy question may be, another issue to consider is the versatility of these proposals to address other scientific questions. Projects such as the LSST, Constellation-X, and the Square Kilometer Array can study many aspects of the universe, including the physics of black holes and the formation of planets. Both JDEM and Constellation-X are options for NASA’s Beyond Einstein program, a broad initiative to study important topics in astrophysics, including cosmology, gravity, and black holes. Another Beyond Einstein candidate, the Laser Interferometer Space Antenna, or LISA, would study ripples in space-time called gravitational waves, and also has the potential to probe dark energy. “Each of these projects contributes in its own unique way, but the dominant [Beyond Einstein] mission whose science goal is primarily detection of dark energy is JDEM,” says Michael Salamon, one of the NASA scientists overseeing the Beyond Einstein program. NASA will decide in the next few months which of the Beyond Einstein probes will go forward next, a decision that might influence the selection of other projects. Although JDEM has three specified candidates, it is still an open com- petition. Any researcher could offer another proposal if JDEM is indeed the next Beyond Einstein mission. “We want to make sure there are a number of viable competing teams,” Salamon says. In most instances, the proposals target dark energy in complementary ways with different strengths and weaknesses. For example, ground-based observatories can be larger and more powerful, but space telescopes can avoid the blurring effect of the atmosphere. Despite difficult decisions ahead, scientists are thrilled about the future. “I have complete confidence that some good choices will be made,” Albrecht says. “This is what science is all about: getting thrown a curveball by nature and plunging in to find out what’s going on. There’s a lot of expertise out there working on it, and I trust there will be a great outcome.” Photos of Michael Turner (middle), Lawrence Krauss (right), boxes and string: Reidar Hahn, Fermilab Photo of Brian Greene (top left): David R. Renneke, Augustana College Photo manipulation: Sandbox Studio 16 WISECRACKS FLY WHEN BRIAN GREENE AND LAWRENCE KRAUSS TANGLE OVER STRING THEORY. BY GLENNDA CHUI

17 symmetry | volume 04 | issue 04 | may 07 Inside, the auditorium at the National Museum of Natural History in Washington, DC, was packed and humming in anticipation. Outside, a man waved a sign at stragglers hurrying for the door: “Need One Ticket for String Theory Debate.” Onstage, there would be surprises. In the hands of two seasoned popularizers of science—theoretical physicists Brian Greene and Lawrence Krauss—what could have been a scientific food fight turned out to be a lively back-and-forth full of zingy one-liners and laughter. The fact that the March 28 debate sold out the museum’s 600-seat Baird Auditorium reflected both the star power of the debaters and the delight people take in ideas that boggle. Greene, a professor of mathematics and physics at Columbia University, Photos: John Boswell began delving into string theory as a graduate student. His first book, The Elegant Universe, sold 1.2 million copies and spawned a three-hour PBS miniseries; his second, The Fabric of the Cosmos, spent six months on the New York Times best-seller list. Krauss—Greene’s “very worthy opponent, in the same height and weight class,” cracked moderator Michael S. Turner—is a professor at Case Western University and a pioneer in applying particle physics to cosmology. Often described as a “public intellectual,” he has written seven popular books, including Hiding in the Mirror: The Mysterious Lure of Extra Dimensions, from Plato to String Theory and Beyond, and the international bestseller The Physics of Star Trek. He has also fought to defend the teaching of evolution in public schools. Turner, a well-known astrophysicist at the University of Chicago, channeled the discussion with a series of questions. Too often, he said in his opening remarks, discussions of string theory— the controversial notion that the fundamental building blocks of the universe are not particles, but tiny, vibrating strings—“have generated more heat than light. There have been some strong statements exchanged, like ‘String theory is a theory of everything,’ or ‘String theory is a theory of nothing,’ or ‘String theory is not a science,’ or ‘Those who don’t embrace string theory will be left behind.’ The only good thing about that last one is I don’t think they’re talking about the rapture.” Later, in an interview, Turner said the problem with this kind of heated debate is that “instead of people going away feeling excited by the science, they feel a little dirty. Well, gosh darn it, there are exciting things going on. Here’s an opportunity to have some high-level discussion.” It was Turner who proposed the event, which was co-sponsored by the Department of Energy’s Office of Science and the Smithsonian Associates. He says he didn’t want it to be the classic high-school-style debate, aimed at scoring points by rhetorically stomping out opponents. Instead, it would use the debate format—and the heightened buzz that debates often generate—to let people know “we are on the verge of a major revolution in our understanding of the universe and the laws that govern it. This revolution, I think all three of us believe, promises to be as profound and as exciting as the one launched by Einstein and others 100 years ago with quantum theory and relativity theory,” as he put it in the debate’s opening moments. Judging from the audience’s reaction, the strategy worked.

18 “I thought it was very thought-provoking,” said Stephanie Gotfried, a teacher from Stone Ridge, Virginia, as she headed for the exit. “It just makes us realize how tiny we are in the big picture. I liked the camarade- rie, and the sense of humor throughout. In my opinion it’s all good even if something doesn’t pan out. It still focuses our interests and allows us to go forward.”

CONTROVERSIAL FROM THE START Although string theory dates back to 1970, the ﬁeld took off in the mid-1980s when researchers realized it had the potential to be the long-sought Theory of Everything—one that uniﬁes the physics of the familiar, everyday world with the odd quantum behavior of atoms and even smaller things. A second wave of theoretical breakthroughs in the mid-1990s drew even more people into string theory research. But skeptics are many, and they came out in full force last year with

the publication of two books critical of the theory: Not Even Wrong, by symmetry | volume 04 issue may 07 Peter Woit of Columbia University, and The Trouble With Physics, by Lee Smolin of the Perimeter Institute in Canada. Right or wrong, string theory has been drawing big crowds—from more than 900 people at the first Isaac Asimov Memorial debate in 2001 to a sold- out crowd at the 2003 Aspen Institute Ideas Festival. More than an airing of opposing views, the March debate in Washington, DC, was also a contrast in styles. On one side of a low wooden table, “STRING THEORY Greene, in black and gray, leaned back in his chair like a guest on a TV talk show. Across the table, Krauss, professorial in a rumpled coat and ENVISIONS THAT tassled loafers, leaned forward, elbow on knee, and rested his chin on his hand, waiting for an opening for the perfect jab. INSIDE THOSE The challenge was to get the talk flowing at just the right level. String theory—actually a set of related theories that differ in the details—is so PARTICLES IS incredibly complex that it takes a solid grasp of mathematics to understand the nuances. SOMETHING ELSE, Yet, according to Greene, it’s also the simplest thing in the world. “In my mind,” he said, “one of the wonderful things about string theory is AND THAT SOME- that although it’s a highly technical subject and you can delve into the mathematical details, the basic idea is far simpler than, say, the basic ideas THING ELSE in relativity and quantum mechanics.” The past decades have seen scientists break down the universe into WOULD BE A smaller and smaller components, from molecules to atoms, to protons, neutrons, electrons, and quarks, and to particles that carry the forces that LITTLE FILAMENT hold all these parts together. String theory, Greene says, “simply takes that picture one step further OF VIBRATING and envisions that inside those particles is something else, and that something else would be a little filament of vibrating energy that we call ENERGY THAT WE a string.” CALL A STRING.” Brian Greene

Brian Greene (far left) and Lawrence Krauss

19 NO EVIDENCE YET Detractors, including Krauss, contend that after 37 years of effort, string theory has produced no experimental evidence to back it up and no testable hypothesis that could lead to those experiments. “The point I want to make is it really hasn’t lived up to its promise,” Krauss said. “It hasn’t really explained any of the things that originally we hoped it would explain. It, in fact, has gotten less and less clear as time goes on what the theory even is, and it’s less and less clear what the ultimate predictions, if it can make them, are.” In particle physics, he added, discoveries come from the interplay between theory and experiment, and “that “THE POINT interplay is missing in string theory. That doesn’t mean it’s wrong, but it means it’s worrisome.” I WANT TO MAKE Greene shot back that the theory does make predictions, but testing them is beyond the reach of current technology. “Naturally,” he said, “you’d like IS IT REALLY to make a powerful microscope and look down and say, ‘There it is, the string!’ But the strings we envision are pretty damned small, about a billion HASN’T LIVED UP billion times smaller than the distances we can probe with even our most powerful accelerators.” TO ITS PROMISE.” He added that no matter how radical string theory sounds, its proponents Lawrence Krauss are not trying to step outside the scientific method: “We will not believe this theory until it’s experimentally tested.” Greene said he’s hoping to find evidence for string theory out in the cosmos, in the heat signature left over from the big bang that gave rise to the universe. Experiments at the Large Hadron Collider, scheduled to start up next year at CERN, a particle physics lab near Geneva, Switzerland, could pro- duce results that, while not directly confirming string theory, would at least reassure its supporters that they’re on the right track. Although it’s a long shot, the collider could bounce particles into other dimensions or detect the vibrational resonances of the strings themselves. On this final point, the opponents found a scrap of common ground. “If I saw a lot of resonances,” Krauss said, “it would be an indication that string theory is heading in what could be the right direction.” Although, he added, it would still not constitute proof. “You’re being really grudging here, Lawrence,” Greene quipped, setting off a collective chuckle from the audience. Nor, Krauss conceded, are there any viable alternatives to string theory at the moment. Turner shot the audience a bemused look over the rims of his glasses. “What I heard Lawrence say is we don’t have any better ideas right now,” he said. “Well,” Krauss said, “I dunno if, well, we…I’ll cede that for the purpose of moving on.” More laughter.

20 ADVANCING SCIENCE Krauss also acknowledged that the theory has pushed research ahead in one respect: “It has caused people to think of what might be possible if there are lots of extra dimensions.” And not tiny ones, either, he said. “There may be infinitely big extra dimensions that we can’t see. It’s a fascinating idea and I have to say it might not have come up except for string theory.” No matter what the pros and cons might be, string theory has attracted hundreds of young theorists, to the dismay of some who fear the field has become unbalanced and that other potentially promising areas are being neglected as a result. Proponents say young people are simply voting with their feet, confirming that string theory is the most exciting thing around. “I do think it’s important to recognize, in the marketplace of ideas, the fact that so many students want to work on string theory,” Greene said. “These are hungry students. I have to tell you that in my experience they

are the most critically minded scientists I have met. They always push symmetry | volume 04 issue may 07 back, to try to find a flaw or a hole in it.” Krauss shot back: “Some of my students have gone on to become rel- atively well-known string theorists. And, you know, I wouldn’t want my daughter to marry one, but still…,” setting off the biggest round of laughter of the evening. He continued, “I firmly believe that students should work on whatever interests them, and physicists should work on whatever interests them. They have to be driven by their curiosity…. The only reason to do this is because you find it exciting and fascinating.” Krauss did add, however, that from his point of view string theory has been in the doldrums for five or ten years, with more students and faculty turning to other things: “I actually think the minute one of the colliders finds something exciting, you’re going to see a lot of rats jumping the sinking ship.” Not so, according to Greene. The field went through two exciting, even revolutionary, periods in the 1980s and 1990s, he said, and while it is not operating at that same intensity today, “it has not been in the doldrums at all.”

THE HARDEST QUESTIONS YET “This is a really difficult problem, the really big picture, and it’s going to take a long time,” said Greene. “I’m saying this is not the time to judge the theory. We are trying to answer the most difficult, the most profound questions in the history of science…. [Even] if we haven’t gotten there in 50 or 100 years, Photos: John Boswell that’s a pursuit we should keep on with.” Greene and Krauss say they’ve been talking about taking their string theory show on the road, not as a debate but as a series of public discussions. With this in mind, both are involved in the World Science Festival scheduled to take place next year in New York City—Greene as co-founder and Krauss on an advisory board. Aimed at the general public, the festival will encompass about 40 events, ranging from lectures and theater, to music and film (see http://www.sciencefestivalfoundation.org/). If the perspectives of the people who came away from the March debate are any indication, there’s still a healthy appetite out there. Dale Newcomb, a 3D graphics programmer from Leesburg, Virginia, had brought his copy of The Elegant Universe for Greene to autograph. His wife, Chris, a technical editor, calls herself a physics newbie. “I think it was interesting,” she said. “They were very witty. It was fun to see them play off each other.” He, nodding: “It could have been very, very dry, but instead…I’ll be back for the next one, that’s for sure.”

21 When the new neighbor’s a giant

Photos: Reidar Hahn, Fermilab 22 At one potential site for the International Linear Collider, people in the community are getting to know the project years in advance. symmetry | volume 04 issue may 07 by Elizabeth Clements

23 “Is your science supporting enough young talent to carry the project along the way?” Mike Herlihy

ike Herlihy is active in the village of North Aurora, near Fermi National Accelerator Laboratory and west of Chicago. He’s been a village M trustee for six years, belongs to the Lions Club and served on an advisory committee to evaluate a proposed freeway. As a principal in a roofing company with a background in civil engineering, he’s particularly familiar with construction and how it can affect a community. So when he read about a proposal to build the International Linear Collider (ILC), a 20-mile-long particle accelerator, near his community, Herlihy took action. He was not alone. Herlihy volunteered to serve on Fermilab’s ILC The Citizens’ Task Force Citizens’ Task Force, a group of 25 community leaders charged with identifying toured Fermilab and met concerns about the possible project—from the way it would look to its poten- with Barry Barish, above, head of the global effort tial economic impact on the region—years before it could become a reality. to design the ILC. On April 30, during its monthly meeting in Fermilab’s Wilson Hall, the group had the opportunity to pick the brain of Barry Barish, the California Institute of Technology physicist leading the worldwide effort to design and build the next-generation machine. Members grabbed cookies by the door, filed into the usual 11th floor meeting room and absorbed Barish’s description of the ILC. Barish started with the big questions about the universe and told the tale of how the ILC came to be—a history that stretches back more than two decades, when scientists first envisioned an earlier design known as the Next Linear Collider. “When you work on a project that lasts many years, it’s interesting the whole way,” he said. For Herlihy, the conversation with Barish added a completely different flavor to the project, opening his eyes to the driving passion behind the ILC. “In validating your “I have a paradigm vision of what a scientist is like, and he painted a theories, what much different picture,” Herlihy says. “He didn’t get embroiled in the facts kinds of things are but instead was challenged by a broader, greater vision.” currently anticipated that could The next big physics machine radically shift this A vision indeed. As proposed by the particle physics community, the ILC whole process?” would be roughly 20 miles long and 300 feet below ground. It would con- Eric Schwarze tain approximately 16,000 superconducting cavities, 13,000 magnets, and 2000 cryomodules—a shopping list that, supporters say, would boost worldwide industry and lead to further technological advancements. As the world’s largest and most complicated slingshot, the accelerator would hurl electrons and their opposites, positrons, toward each other at nearly the speed of light. The resulting collisions could reveal the makeup of the dark matter and dark energy that constitute 96 percent of the universe, leaving just 4 percent for familiar, ordinary matter. Nearly 1000 scientists around the world are contributing to the design of the ILC. A global research plan is under development; the design team hopes to begin picking a site by 2011, and start construction as soon as 2012. If the United States decides to submit a bid to host the collider, the Department of Energy has expressed interested in building it at Fermilab.

24 “What are the factors in determining the site? What body makes the decision?” Charles McCormick

With 10 square miles of land, Fermilab has plenty of room for its resident herd of roaming buffalo but not enough for the 20-mile-long ILC. While the main operations, such as the detectors and beam sources, would be on the Fermilab site, the tunnel would extend well beyond the lab’s boundaries. Several access shafts, each roughly 30 feet in diameter, would be located off site, along with a number of buildings needed for cryogenic equipment and other instrumentation—some as large as a “big box” store, such as Target.

Plenty of volunteers Top: Facilitator Doug Sarno When Fermilab sought nominations for the ILC Citizens’ Task Force late last year, it was inundated with responses. Twenty-ﬁve people were selected, Middle: Fermilab theorist Chris Quigg illustrates basic ranging from a mayor to an environmentalist and a school superintendent, concepts of collider physics representing a broad range of perspectives and interests. “We want this with a slide show. panel to look and think like the region,” says Doug Sarno of the Perspectives Bottom: Task Force members Group, a consulting ﬁrm that specializes in public participation, who is Joe Suchecki (left), Jayme facilitating the meetings. “This is a really critical piece of the puzzle for us, to Muenz and David Brummel understand how this region will look at and think about the ILC.” No matter where the ILC ends up—countries in Europe and Asia have also expressed an interest in hosting it—the lessons learned from Fermilab’s task force may well apply to those regions as well, which is one reason Barish is cultivating a dialogue with potential neighbors now.

For Barish, whose average day might include meeting with world scientiﬁc symmetry | volume 04 issue may 07 leaders, presenting proposals to funding agencies, lecturing at institutions or even receiving an honorary degree, as he did from the University of Florida in May, it was an unusual experience. Meeting with the Fermilab task force gave him an opportunity to learn from another group of people with a big stake in the outcome of the project, one whose voices may ultimately be the loudest of all.

25 Fermilab first experienced the powerful influence of its local community Above, task force members in the 1980s when the Department of Energy proposed Fermilab as a gaze out over the Fermilab possible site for the Superconducting Super Collider, a 54-mile oval-shaped grounds, a potential site for the big collider. The 20-mile- accelerator. A local citizens’ group called CATCH, or Citizens Against the long collider would extend Collider Here, spearheaded community opposition to the project. Eventually beyond the lab’s boundaries, a site in Texas was selected; however, the project was shut down before and community support is essential. construction was finished. So meeting with the community early on “is very healthy, independent of where the ILC gets sited,” Barish says. “It is not as formal as talking to the funding agencies, where everyone wears a certain hat and has an agenda. The task force members each have their own identities too, but they took off their hats for this meeting and that really made this a different kind of conversation.”

Going to boot camp The task force’s first order of business has been to get the information it needs to weigh in on the pertinent issues. The members have been going to particle physics boot camp, a crash course on everything they ever wanted to know about the ILC, including how the machine works and why the scientific community wants to build it. The group’s meeting with Barish was the last step in that education. Much to Barish’s surprise, the members did not ask him to justify the high cost of the project or explain why it is so important. Instead, they focused on the science: Why does the accelerator have to be linear rather than circular, like the lab’s Tevatron collider? Why smash electrons? What happens after the ILC? Warrenville mayor David Brummel asked, “Is there a precedent for the way this is going to happen? Do we have anything that is already working at this level or will it all have to be created?” Barish responded that there is another large accelerator, the Large Hadron Collider, about to open at CERN, the European particle physics lab near Geneva. “It is not completely global,” he said, “but it is quite international in participation. But establishing an international project isn’t the biggest problem, to be honest with you. The big worry is how do we put together an international management while simultaneously doing the R&D?” Members of the task force say they were surprised by the sheer intrigue of the science. For some, learning that only four percent of the universe consists of ordinary matter was mind-boggling. For others, the marriage between science and technology was most exciting. “What has amazed me the most so far is that these scientists believe that leading with the wonder of physics is the best way to make people care,” says Eric Schwarze, an administrator and lecturer at Aurora University. “I think you are starting to convert me on that.” The scientific case for building the ILC may be enough to inspire, but the task force is just beginning to sink its teeth into some of the trickier issues, such as property rights, environmental protection, and safety. One concern it has already raised is the time-frame for building the ILC. By the end of this decade, the scientific community hopes to be in talks with governments around the world about siting, building and paying for the

26 collider. According to this time-frame, major construction would occur over The task force represents a a period of seven years and scientific operations would begin around 2019. broad range of people in the community, from a school However, obtaining international agreements, making funding arrangements superintendent to a mayor, and selecting a site could delay the project by several years. an environmentalist and a principal in a roofing firm. They’ll meet through the end A long timeline of this year. “It is so far out there,” said task force member Joe Suchecki, director of public affairs for the Engine Manufacturers Association in Chicago. “If it is that far away, what does that mean for Fermilab? Will the task force have to start all over again?” Herlihy raised a concern about the timeline that he can personally relate to—manpower. “I’m in the roofing business, and ten years from now, we will be going through a wave of retirements,” he says. “This is a real challenge for us. Is your science supporting enough young talent to carry the project along the way?” Barish responded, “We have to worry about manpower, and it’s a concern. There is the talent to do it but it will take good leadership to make sure we have the skills we need. It is a very good question, and there is no real answer.” The task force will continue to meet through the rest of the year, weigh- ing in on such things as the orientation of the machine, where the under- ground tunnel, buildings and other structures might be located and how the symmetry | volume 04 issue may 07 community’s role in Fermilab’s long-term mission can be strengthened. Then it will discuss what the next steps should be. “I may not be able to draw the physics on a whiteboard, but I understand so much better the intrigue—what is motivating the science and the need for the machine,” Herlihy says. “Now we are ready to transition into the elements that we can relate to in our community.”

27 day in the life: katie and adam yurkewicz

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after almost a year of preparation, we packed up all our belong- In August 2006, ings to move from Batavia, Illinois, to Geneva, Switzerland. We were following our particle physics careers from Fermilab to CERN, the European particle physics lab–Adam to work on the ATLAS experiment and Katie to serve as US communicator for the Large Hadron Collider. We said goodbye to friends and our coworkers at Fermilab; divided our belongings into Europe-bound and storage-bound; spent a week with each of our families in New York; and finally set off on separate flights to Geneva in September. Two months and one lost suitcase, three rental cars, five apartment viewings, dozens of hours of bureaucracy, and countless French-transla- tion errors later, we were living in an apartment in the French countryside, owners of a French used car, and beginning to settle into our new lives and routines. 4

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What to take, what to toss, what to put in storage for three years in my parents’ garage? For the most part practicality prevailed–clothes to Europe, fragile china to storage–but somehow a $10 globe, 100 plastic cookie cutters, and a large collection of refrigerator magnets were deemed worthy of shipping 4400 miles.

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Separate employers, separate travel itineraries from New York. I ﬂew Swiss airlines direct to Geneva; Adam’s layover in Heathrow resulted in the temporary loss of his carry-on bag containing all our electronic equipment and important documents. The bag eventually turned up with all contents intact, but not before a week of bureaucratic wrangling that spiced up our arrival in our new city.

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After six moves in nine years, we thought we had apartment-hunting down to a science, but it’s a whole new thing in a whole new country. We eventually chose an apartment in the tiny town of Vesancy, France. What our town lacks in nightlife, it makes up in cows, mules, friendly neighbors, and hiking in the Jura Mountains right outside our door.

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Apartment, car, belongings arriving safely from the US were all important mile- stones. But once the big things were done, we started the real job of adapting to a new culture: learning the language; driving a manual transmission; adapting to local shopping habits; eating different types of food; and even ﬁnding time for some sightseeing. No matter how comfortable we may get in Europe, care packages from home are still always highly anticipated.

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29 symmetry | volume 04 | issue 04 | may 07 gallery: arrows of time

says he does not “We basically had a correspondence, visually Ken McMullen feel comfortable and in discussions, with physicists, both theoretical with categories. That’s why when, given a choice and experimental, and engineers,” McMullen says. between defining himself as a painter or a film- Out of that interaction came an exhibition that trav- maker, he prefers to be called an artist instead. eled all over the world, from New York to Beijing. He also does not believe in the separation McMullen, who says he studied physics “until between science and art, and mixes both disci- a reasonable level” in school, believes this partic- plines in many of his films, as he did in his latest ular scientific discipline offers “one of the deepest work, Arrows of Time. McMullen calls it a “very ways into how nature works.” He says that radical new form of cinema” that mingles high- whether physics is peering into the smallest or energy physics and astrophysics concepts largest scales, it is actually trying to define our with tidbits of philosophy and poetry. position in the universe. The advantage of this The British artist is a research professor at approach to the meaning of life, McMullen says, is the University of the Arts London and lectures that “physics offers potential points of clarity which extensively on interdisciplinary artistic practice. can be confirmed, whereas the mystic offers a kind He started his love affair with physics while of clarity which can never be confirmed.” directing a project called “Signatures of the Arrows of Time consists of 40 interchange- Invisible”, which brought together artists and able elements. Ten deal with literature, 10 have scientists working at CERN, the European particle an action element, 10 revolve about a central physics facility near Geneva, Switzerland. character, and the remaining 10 have to do with

30 Filmmaker Ken McMullen

contemporary physics. These elements are com- between different forms of activity.” McMullen bined in a different order for each showing, so lets the spectator decipher the meaning of images, that “you would never have enough seconds in such as a woman in a white dress swinging a your life to watch” all the possible combinations, bright light around her head or living reproduc- McMullen says. tions of classic paintings. For the film’s April 27 premiere at the Museum McMullen has made several visits to the of Modern Art in San Francisco, McMullen chose Stanford Linear Accelerator Center to film con- to construct several timelines, each with its own versations with physicists. combination of elements. “What I do with the camera in this context is “I juxtaposed these components in different just making a diary,” he explains. “Imagine if you situations, so you may have a theorist like Michael had had a camera in the time of Copernicus and Peskin talking about dark matter next to a poem you were able to see him arguing with the by Fernando Pessoa, where he describes a time church, or just making a statement. This would when suddenly a blindness has been lifted and be an amazing thing to see, because we would he can see for the first time,” McMullen says. He be able to see a transition in human culture.” He sees parallels between the two situations: Both believes physics is arriving at another shifting represent moments when suddenly one can see point, and he wants to be there to film it. from a unique perspective. “When you put these items together in a timeline,” he says, “you begin Text: María José Viñas to see that there is a great correspondence Stills from Arrows of Time: Ken McMullen symmetry | volume 04 issue may 07

31 essay: pierre schwob

they communicate the great beauty and drama of the scientific enterprise. But reading about science was not quite enough. I needed to get up close and personal with the scientists and their heroic experiments. I began to visit many of the major observatories and laboratories around the world so I could meet with the people who do the actual work and learn directly from them. This led me to the Stanford Linear Accelerator Center in California; the CERN particle physics lab near Geneva, Switzerland; several mountain tops in Arizona; Mauna Kea in Hawaii; the Atacama Desert in Chile; the South Pole; and many other fascinat- Launched into science ing places. Eventually, I was able to offer some Sputnik, the first satellite sent into Earth orbit, support to the Kavli Institute for Particle was launched October 4, 1957–my 11th birthday, Astrophysics and Cosmology at Stanford/SLAC so I remember the date. It was also the first time and I began to attend as many colloquia and I found my father seemingly interested in science conferences there as my schedule allowed. and technology. I was to learn enough to understand, on a wildly

Photo courtesy of Pierre Schwob I understood later that my dad’s reaction had charitable average, about half of what was more to do with the fact that it was the commu- being discussed. nists who had launched the thing. Nonetheless, When asked if I understand a particular sci- I was most impressed by the idea that one could entific topic, I sometimes reply that I am like a tune a radio receiver to hear transmissions from blind man in front of the sun: I cannot see it, but a man-made object in space. I began to read what I can certainly feel its heat. This allusion to I could about radio, rockets, space, and the stars. different wavelengths brings me to observe that This opened a wonderful perspective for me: I feel particularly fortunate to live in a most We humans are rather puny creatures, but we remarkable scientific era when cosmology is can think! Pascal’s words “Man is but a reed… becoming an exact science, where data is being but he is a thinking reed” resonated strongly, as collected and experiments can validate or dis- did “The universe is an infinite sphere whose prove theories. It isn’t theology anymore! center is everywhere and circumference nowhere.” I close by noting that I have found all the sci- My natural inclination is to understand things entists I’ve met, from the most modest grad stu- within their context. And I cannot imagine a bet- dent to the most exalted Nobel Laureate, not ter context-providing starting point than the study only approachable but also wonderfully eager to of cosmology and astronomy. The more I read, share their passion, and delighted to see an taking particular pleasure in the history of science outsider showing an interest in their work. They and in the learning of the scientific method, are all so very generous with their time and I the more I became fascinated by the astonishing thank them infinitely for this. My only wish is that advances made toward our understanding of the more of us, the voters who fund a great deal of universe and our place in it. (Perhaps to Pascal’s this (sometimes fairly expensive) enterprise, come chagrin, this drove me to evolve into a comfort- to learn of the inestimable value these people able agnosticism.) are providing our society and our civilization. I sometimes regret that I did not become a Although I know the Earth will not support life physicist, but various factors led me in other forever, I suggest that it is better to die in the directions and I ended up making a career as a evening so that one can learn something that computer scientist and entrepreneur. (My first last morning.

mark was made in the ﬁeld of radio data recep- Pierre R. Schwob symmetry | volume 04 issue may 07 tion. Should I thank the Soviets for this?) While making a living and eventually raising a family, Pierre was raised in Geneva, Switzerland, and has lived in New York, Hong Kong, and now Palo Alto. He has taught computer I continued to read what I could about science science and licensed his intellectual properties in radio data and and, in particular, follow developments in cos- Internet technologies. He’s also written books on chess, mology, astrophysics, and particle physics. calculators, and history. He now runs ClassicalArchives.com and spends quite a bit of time at the Kavli Institute for Particle I must express here my heartfelt gratitude to Astrophysics and Cosmology, whose computer center he the authors of popular science books and mag- has endowed. azines. Their efforts provide incalculable enlight- enment to the rest of us and, as importantly,

32 logbook: the blue book

at the Stanford Linear Accelerator Center (SLAC) Affectionately known as simply “The Blue Book,” The Stanford Two-Mile Accelerator has been a classic on site since the day it was published in 1968. Shepherded into existence by an editorial committee of four SLAC staff members led by Richard B. Neal, the massive 1169-page, more-than-ninety-author treatise thoroughly documents all facets of the two-mile-long linear accelerator, or linac, operated by Stanford University. The blue clothbound book was conceived upon the realization that the staff working long and hard on the project would inevitably disperse upon the linac’s completion. As a means of preservation, the volume was created to provide a systematic presentation of the knowledge and experience gained in the linac’s design and construction. The editorial committee divided the material into 27 chapters covering all aspects of the site, including buildings and utilities, as well as the components and systems of the accelerator and the beam switchyard. The SLAC linac is the longest linear accelerator in the world, and aspects of its design continue to be of interest not only to SLAC staff, but also to a wide range of accelerator designers, users, and builders. The page reproduced here is from an author’s proof of the book, currently being held in the collec- tions of the SLAC Archives and History Ofﬁce. Since the excerpt is from a true “blue-line” proof, this particular copy is blue both inside and out. Jean Deken, SLAC archivist Image courtesy of SLAC explain it in 60 seconds

proposes that the fundamental constituents of the universe are one- String theory dimensional “strings” rather than point-like particles. What we perceive as particles are actually vibrations in loops of string, each with its own characteristic frequency. String theory originated as an attempt to describe the interactions of particles such as protons. It has since developed into something much more ambitious: an approach to the construction of a complete uniﬁed theory of all fundamental particles and forces. Previous attempts to unify physics have had trouble incorporating gravity with the other forces. String theory not only embraces gravity but requires it. String theory also requires six or seven extra dimensions of space, and it contains ways of relating large extra dimensions to small ones. The study of string theory has also led to the concept of supersymmetry, which would double the number of elementary particles. Practitioners are optimistic that string theory will eventually make predictions that can be experimentally tested. String theory has already had a big impact on pure mathematics, cosmology (the study of the universe), and the way particle physicists interpret experiments, by suggesting new approaches and possibilities to explore. John H. Schwarz, California Institute of Technology

Symmetry A joint Fermilab/SLAC publication PO Box 500 MS 206 Batavia Illinois 60510 symmetryUSA

Ofﬁce of Science U.S. Department of Energy