Lisa Randall. “One challenge today is to see what you can do with large amounts of data, to study fundamental properties, not just questions of how electromagnetism gives rise to certain things. Can we actually see deviations from what you would predict in conventional theories?” Rami Shllush Understanding a warped cosmos What’s the connection between dinosaurs and dark matter? What is the glue that holds the universe together? Is there a fourth - and fifth - dimension? These are just some of the questions that occupy Lisa Randall, the first female physicist to get tenure at Princeton, Harvard and MIT

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The CERN facility, near Geneva. “We need higher-energy machines and particle Illustration of a large asteroid colliding with Earth over the Yucatan Peninsula, in accelerators,” says Randall, “but to really see new things, we need even more Mexico. The impact of such occurrences are thought to have led to the death of the powerful machines.” Richard Juillian/AFP dinosaurs some 65 million years ago. Mark Garlick/Science Photo Libra Ido Efrati

in the sciences. In 2016 he mystery of the universe,be seen as evidence that dark matter Over the years, studies have specializes interview with The New she and the many riddles that re- interacted in some way with hydrogen mapped the presence of dark matter Yorker, related that in her teens she had fre- main open about itcan be ex- atoms, thus leadingto the loweringof in various placesin the universe,in- the of the dark matter. our emplifiedin myriad ways. temperature eludingin the center of galaxy,the quent confrontations with her mother, to One of the most frustratingPhysicistsresponding the article Milky Way. In her most recent book, who was reluctant to lether leave for nature challengesinvolves the fact that sci- in suggested that the discov- “Dark Matter and the Dinosaurs: The school before dawn so she could ar- ence is familiar with less than five ery could open new direction into Astounding Interconnectedness of rive in time for the early-morning the of dark matter and the uni- percent of the matter that makes up study the Universe” (HarperCollins,2015), meetingsof the school’smath team, of the universe. That iswhat Randall takes dark matter and its paltryfigure verse.) pos- which she was captain(thefirstgirlto after allthe matter The 69 of the sibleeffects one you get addingup remaining percent step further,linking serve in that capacity). on Earth and outside it all for the observed behav- its in our solar with including “explanation” presence system At age 17,Lisa finished firstin the the galaxies,solar systems, and such ior of the universe is the postulationthe extinction of nearlyallof the dino- prestigiousWestinghouseScience Tal- as that there is some sort of out saurs some 66 million heavenlyobjects asteroids,meteors, energy years ago. ent Search (asit was then known), gas clouds and interstellardust.Effec- there that researchers called “dark The unusual connection between nationwide science competition for tively,everythingthat’smade of atoms. energy.” dark matter and dinosaurs proved ir- high-schoolseniors. The problem was that science could This force did not enter the theoret- resistiblyintriguingon the lecture cir- She entered Harvard in 1980,and not explainempiricalobservations of ical pictureuntil the end of the 1990s, cuit and TV talk shows. Her research by 1987 had obtained doctoral de- the universe based on the matter and on the basis of observa- on this with of surprising subjectbegan survey gree in particlephysicsthere. She was events energieswe know about. The bafflingtions of supernova (theexplo- allthe known craters on Earth with the first woman to receive tenure in conclusion of centuries of observations sion of which revealed that the stars), diameter of more than 20 kilometers the physicsdepartment of Princeton and calculations is that the matter and universe is not and only expanding and which are no more than 250 mil- Universityand the first female,ten- that have been identifiedcon- but is acceler- energies spreading, constantly lion years old.There are 26 such mon- ured theoretical physicistat Harvard. to be 4.9 the with which itdoes so. stitute, precise,just percent ating speed ster craters, all created,according She also served as tenured professor had been that the ex- of everythingin the universe. So what (The assumption to the geologicalevidence,by large at MIT, else is out that we haven’t seen? was because of there, pansion decelerating, objectsthat slammed into the planet. Her research deals with diverse as- the effects of The basic Scientists call the mysterious95.1 gravity.) argu- Randall found consistent cyclicality pects of theoretical physicsand with ment for the existence of dark percent of whatever is making up the energy in the formation of the craters, with the studyof the universe (cosmology), universe “dark matter” and “dark en- is that there must be hidden force new one having appeared approxi- coveringthe gamut from elementary It’scalled “dark” because itcan’t that is the from ergy.” pushing galaxiesaway mately every 30 million years. The particlesthe minuscule,basic matter be not in the form of celestial one another. seen, reason for this recurring cycle,she of which the materials of the universe bodies or even dust clouds. Nor does When met the Frank B. Randall, argues, is to be found in the cyclical- are constituted to understanding it to interact with the Jr. Professor of Science at Har- appear particlesBaird, ityof the solar system’scircumnavi- space itself. we do know asked she chose to focus about,includinglightpar- vard, why gationof the Milky Way once every The “standard model” of particle tides. her research on dark matter. physics 30 million years. physics,formulated in the 1970s,de- It is on dark matter that Prof. Lisa Our interview took placeat the Dan scribes the structure of matter on Randall, physicistat Harvard Univer- Carmel Hotel,in Haifa. small scale. The model refers to the sity,hopes to shed light. “I think that dark matter is justat reciprocalrelations between the dif- day before Randall arrived in ferent atomic which are di- very interestingjuncturerightnow, ‘Ibelievethere’slifeon other particles, Israel,this past December, to partici- vided into called because we know it’sthere,but we particles “bosons,” pate in the annual conference of the on don’t know what it is. And, depend- planets.don’t believewe’ll which carry the forces that act IsraelPhysicalSociety,U.S. President matter, and “fermions,”from which ing on what it is,there can be differ- finditor know about Donald Trump forbade the Centers for it, all the of matter are ent ways to look for it.My research is particles made, Disease Control and Prevention, U.S. with the forces that act on them. being conducted in areas that others but do think along health from the necessarily, public agency, using haven’t looked at.” The model, which describes the ba- terms “evidence-based” and “science- it’sthere.Everytime we’ve sic interactions in contains But are you certain that itexists? nature, based” in documents. Ran- budgetary three forces: They are known as the “I would say yes. There are many decided we’re uniqueor dall openedher talk at the conference, nu- different piecesof evidence that point “strongnuclear force,”the “weak which was held at the Technion Is- thatwe’re the we’ve to its existence. We see how stars center, clear force” and the “electromagnetic rael Institute of Technology,in Haifa, force.” move in our galaxy;we see how gal- been don’t see on December 17,by saying,“It’snice wrong. to Prof. Yael axies move in galaxyclusters.We also According Shadmi, to speak at conference in country we should be the theoretical at the see evidence in cosmic microwave why only physicist Technion, where you can stilluse the word ‘sci- who has worked with “As background radiation,left over from Randall, ence.’” exampleof anything.’ the earliest moments of the universe.” of today,we have beautiful theory Her barbed remark reflects the ap- called the ‘standard which de- (Randallis referringto radiation that model,’ prehensionof many of her colleagues is kind of remnant of the Big Bang, scribes allvisiblematter and itsinter- about the future of scientificresearch the event that brought the universe actions,with the exceptionof gravity, in the United States in lightof the The blow to Earth isrelated in terms of small number of into beingnearly14 billionyears ago. cyclical very Trump administration’s approach.In to two We The radiation isan artifactthat serves phenomena, Randall believes. elementaryparticles. understand the meantime,though,Randall contin- One is familiar from the weak and as somethinglike photographof the concept space strong, electromagnetic ues to occupy herself vigorouslywith as as state of the universe at itsgenesis,and research known the “Oort cloud.” forces stemming from symmetries. the bigquestionsof the universe,in- The second is Randall’s of The weak force is related to broken its existence is one of the proofsthat theory eluding,most recently,the nature of the existence of the “double-disk dark the Big Bang occurred.) symmetry.” dark matter. matter.” Shadmi: “The which “In contrast to dark energy, dark Higgs boson, If less than five percent of what The named for the was matter is,after all,matter, which Oort cloud, 20th- discovered in 2012,is responsible comprisesthe universe iseven known for this and its means it can interact,it can clump century Dutch astronomer Jan Oort,is symmetry breaking, to science,what can it say about the mass determines the of the differently,it could take on certain thoughtto consist of billionsof blocs strength rest? Scientistsestimate that some 26 weak force. But there are fundamen- shapesand sizes and exist in different of ice that are the source of many of percent of the universe is dark mat- concentrations in galaxies.So there’s the meteors, the long-tailedicybod- tal problemswith the theory in addi- ter. The search for dark matter began tion to the fact that it doesn’t lotof research to be done to figure ies that look like fallingstars as they explain in the 1970s. The idea of its very ex- dark matter. Randall out what we can reallypredictfrom hurtle across the galaxy. investigated istence arose in an attempt to explain various extensions of the standard these models,and understand what we Randall’s double-disk dark matter the speed at which galaxiesrotate model in order to contend with these hope to see. is postulatedto be largeexpanse of around their axes in the cosmos. The One of the “Peopleoften ask me, ‘You haven’t dark matter in the center of the Milky problems. major questions measurements, which didn’t corre- raise relates to the of seen it,so how do you know it’s Way galaxy that possesses immense they strength spond to the known effects of gravity, the weak force. The weak force is there?”’ Randall says, in response to gravitationalattraction. According led scientists to postulatethe exis- times than which she usuallycompares the inves- to her theory,once every 30 million many stronger gravita- tence of additional matter, not visible and we have no for tigationof dark matter to an unidenti- years that is,once during the solar tion, explanation to the eye or measuring devices,that this fied celebritywho comes to town for system’sorbital cyclearound the gal- hierarchy.” exercised gravitationalinfluence,and Randall’s best-known research visit.“You know that celebrityis axy situation forms in which the could in the that part explain speeds of the dark mat- work theoretical model she devel- there because you see peoplegather- gravitationalpull were calculated. with the Raman Sun- ter disk causes meteors to be oped physicist ing around, and there are cameras, large (In an uncanny coincidence,this known as the “Randall-Sun- “wrenched” from the Oort some drum, but you don’t necessarilyknow who it cloud, week saw dramatic developmentin drum model,”and publishedin 1999 is.It’sthe same with dark matter: We of which then proceed to collide with the of dark matter. In an arti- study Earth. Randall isthe “sea- hypothesizedthat hierarchyof this see itsgravitationaleffects on other That, says, cle in the prestigiousjournalNature, kind is created because space actually matter, on visiblematter, so we know son” in which the large craters are Prof. Rennan Barkana, head of the possesses four dimensions. The extra, it’sthere,but we’re stilltryingto fig- created. astronomy department at Tel Aviv fourth,dimension is warped, and is ure out what itis.” One such crater,called Chicxulub, University,described how the EDG- for the vast difference be- which was discovered in the 1970s by responsible ES radio telescopein Australia had tween the weak force and employeesof the Mexican oil compa- gravitation. pickedup radio wave datingback to stars “The Randall-Sundrum model is Falling ny Pemex, on the edge of the Yucatan much earlierperiodin the historyof one of the most influential works in In her Technion lecture,Randall Peninsula,was studied and dated. The the universe. The signalserves as the and has that the existence of dark crater was created by an impact with particlephysics, important firstdirect evidence of dark matter’s explained Earth close to the time of the theoretical implications. great matter was firstpostulatedon the ba- very abilityto interact with regularmateri- many other works were publishedin sis of the rotational speed of stars in great dinosaur die-off,Randall says. als. It providesnew testimony about itswake,”Shadmi says. our galaxy.In certain cases, she said, the after It’sdifficultto the model in mysterious period shortly the motion of the stars in their orbits Fourth dimension explain the universe came into plainlanguage or, for that matter, in being, peri- is so without rapidthat, hypothesizing Lisa Randall was born in Queens, od described as the era of “the cosmic complex language.Generally speak- the existence of dark matter that is, New in the second of three the when the York, 1962, itdescribes world in which an- dawn,” meaning period without the existence of ing, gravitation-children,to father who was sales- firststars were some 200 mil- other dimension exists (afourth,or formed, al force in addition to that of regular man and mother who was primary lion years after the (which, fifth,if the time dimension is includ- Big Bang matter we would these stars expect school teacher. Her impressivemem- accordingto current understanding, to lurch out of those orbits.Today it’s and interest in mathematics were took about 13.8 billion ory place years that without dark clear matter, galax- evident from an age. She attend- The are still early ago). findings prelimi- ies and clusters would not even galaxy ed the nary, and extensive prestigious,publicStuyvesant require analysis, have come into being. School in which but ifthey can be confirmed,they can High Manhattan, ed), which generates spatial warping ergy to produce these particles,” she and non-uniformity. Its existence, notes. “But maybe at the Large Had- though, can explain at least some of ron Collider [at CERN, the European the problems and contradictions that Organization for Nuclear Research, in engage physicists as they try to de- Switzerland], or a machine like it, we scribe regularity in nature’s behavior will be able to reach the energy where with different criteria. you can see these things.” “The extra dimension is very In addition to being a research sci- small,” Shadmi says. “It’s like a nar- entist, Randall is a successful author row pipe which, if looked at from afar, of popular books on science. Her books will appear to be a thread; we will “Warped Passages: Unraveling the not see its thickness. But an ant that Mysteries of the Universe’s Hidden walks along the pipe sees that it also Dimensions” (2005) and “Knocking on possesses circumference. The warped Heaven’s Door: How Physics and Scien- character of the extra dimension can tific Thinking Illuminate the Universe be likened to a pipe whose thickness and the Modern World” (2011) both made changes. If you were to walk along the the New York Times list of notable books pipe you would see different scales of of the year. “Warped Passages” also energy. The Higgs is located at the served as the basis for the libretto wrote far end of the pipe, where the energy for the opera “Hypermusic Prologue: A scale is lowest. That’s what creates the Projective Opera in Seven Planes,” with large differential between the basic music by Spanish composer Spaniard energy scale, which is characteristic Hector Parra. of gravitation, and the Higgs mass, How do you go about writing books which determines the weak force. It of popular science about such com- sounds very abstract, but the extra plex subjects? I don’t even know how dimension has measurable implica- I will be able to make our conversa- Yael Shadini, of the Technion. “The extra dimension has measurable implications.” tions.” tion accessible to readers of Haaretz. Rami ShUush The model stirred considerable “It’s a lot of work, to be honest; I interest in the scientific community mean, it takes years. Honestly, I some- “The answer is yes and no. The Do you believe that intelligent life and served as a catapult for Randall’s times look back and think, ‘How did I launch of the Large Hadron Collider exists elsewhere, too? reputation and career. Between 1999 do that?’ But I guess there are a few and the discovery of the Higgs boson “Yes. I believe there’s life on other and 2004, she was the most quoted reasons I want to do it. One is that it is were magnificent. The discovery of planets. I don’t believe we’ll find it or scientist in articles about theoretical very easy to look at books and say, ‘I gravitation waves is fantastic. But know about it, necessarily, but I do think physics; in 2007, she was included in don’t like the way this is written.’ But those theories had been around for it’s there. Every time we’ve decided we’re Time magazine’s list of the 100 most I thought, ‘Can I actually do it better?’ 50 years and more. What’s different unique or that we’re the center, we’ve influential people in the category of I wanted to write books for people who today, I think, is that data process- been wrong. I don’t see why we should be scientists and thinkers. really want to understand what’s go- ing is improving, which means that, the only example of anything. But that We are barely getting along with the ing on. Many science books are a little if before we were always looking for doesn’t mean we have access to it.” four existing dimensions, and you had condescending, or they talk very au- clean, precise measurements - which It’s impossible not to refer to the gen- to add yet another dimension. How do thoritatively but don’t actually let you are still absolutely important - one of der issue in your case. You’re thefirstfe- you arrive at these kinds of ideas and know why we’re asking what we’re the challenges today is to see what male physicist to be tenured at three top conclusions? asking or what we’re doing. you can do with large amounts of universities, and that’s a detail that’s al- “It was fun for me to think ere- data, to study fundamental proper- ways mentioned in connection with your Randall: “That’s the great thing atively about how I can explain these ties, not just questions of how elec- activities. Why are there so few women about doing physics: You can think in ideas and tie them together in differ- tromagnetism gives rise to certain in theoretical physics, and what does ways that allow for a fifth dimension. ent ways, and come up with different things. Can we actually see devia- that tell us about the status of women It’s not obvious that it’s there. In this analogies. In each book I wanted to say tions from what you would predict in in this area? case, it could be particles that carry something a little bit different, too, “It’s a good question. It’s hard to momentum in another dimension.” conventional theories? So a lot of my about how we do science. Especially imagine that in the best of all possible Momentum is defined as mass mul- research today is devoted to that kind in the United States, where there is so worlds, the imbalance would be so great. tiplied by speed, and it expresses the of question. much confusion about what science is But it’s also hard to say it’s due to any one intensity of motion of a particular body “In regard to the discovery of new and how it works.” particular thing. I do think that we tend or particle. What Randall is referring particles, I think we need higher- Her latest book, “Dark Matter and energy machines and particle accel- to give guys the benefit of the doubt a to is that the extra dimension might be the Dinosaurs,” she explains, “is about erators. Some things are improving lot more than we give women. I mean, the question of how we got to where we all the time, like precision measure- we’ve seen this in politics. No woman are. I wanted to tie together the evolu- ments. But to really see new things could say things as stupid as Donald ‘Dark matter is, after all, tion of the universe, the evolution of we need even more powerful ma- Trump said and be elected. We don’t the galaxy, the evolution of our solar chines. There are constant new de- realize it, but there are many subtle ef- matter, which means it system, and even life. This was a good velopments, but we might have to wait fects going on. I think people judge men and women differently without realizing can interact, it can clump opportunity for doing that. It’s not just [longer] for those that will be most it. In conferences I attend, most of the differently, it could take making sure people can understand meaningful.” the ideas, but also making them want What is the greatest challenge in participants are men. I mean, there are a few more women than there used to be, on certain shapes and to read about them.” cosmology today? but it’s not progressing as quickly as you These days, however, says Randall, “The challenge is to figure out exist might think it would.” sizes and in different she is not working on a new book, but which are the best research oppor- Why is that, do you think? rather is focusing on her research. tunities. Theoretically, we can make concentrations in galaxies. “There are major, fundamental dif- The prevailing feeling in many progress on many fronts, but the ques- ferences all through society in the way So there’s a lot of research circles is that we are in a new and ex- tion is where we can make progress men and women are treated, and I think citing era of cosmology, witnessing both in understanding and in verify- to be done - to figure out that just filters down. So there aren’t a milestone in the technological de- ing. We have finite resources, so how many women in theoretical physics. what we can really predict velopments in these realms. In 2012, do you best dedicate them to really Even if there are some specific prob- physicists finally succeeded in iden- making progress?” from these models, and lems that might exist in this regard, I tifying the Higgs boson, the particle How much of a role does techno- think it’s part of a larger cultural issue understand what we hope whose existence had been predicted logical ability play here? that needs to be addressed. I have to say half a century earlier, in the LHC “There’s definitely a sense that to see.’ that one of the reasons I’ve written popu- particle accelerator at CERN, Since we’re close, but there’s a big differ- lar books is to show what women, as well 2015, the existence of the gravitation- ence between being close and reach- as men, have done in the field,” al waves postulated by Albert Einstein ing the goal. As a theorist, I’m not con- Do you think that women with your a century earlier has been verified by ducting experiments. The best I can manifested in the existence - along- standing should work to change the side the familiar particles, such as the means of specially designated facili- do is say, ‘This is the way things are. situation? electron - of another whole family of ties possessing unfathomable sensitiv- Are there things that we’re missing? “No. I think we should be allowed to particles with greater masses, which ity, in the United States and Europe. Are there ways that we can interpret do whatever we want, because it’s so impart to the fifth-dimension particles Science has greatly developed its abil- the data so that we can learn more hard to do physics in the first place. ity to observe the depths of the uni- than we thought we could?’ That’s their power. The best thing is to do physics the best She continues: “The challenging verse and to analyze behaviors and how the discovery about gravitational I know how, and to write good books. I question for a physicist is to identify traits of objects, planets and various waves was finally made, but it took 50 don’t think there should be any extra the subtle clues that indicate the ex- phenomena. Within a short time, a list years. We could do the same for par- demands on women.” istence of this type of matter, which tide physics: talk about what we’d like has been formed of more than 5,000 to see in the future, but at the same we never anticipated. And that to me planets that possess features similar is very interesting.” time talk about what information we to those of Earth. can extract from the measurements Have we reached the stage where we already have. It’s a combination A man’s world science has the technologies that will of those two: how to disperse our re- allow it to confirm or refute different search resources optimally, but also What Randall and her colleagues theories about the universe? Is this the are looking for in this case are singu- how to analyze the existing informa- era of answers to the basic questions tion and learn more.” lar particles that look and interact like about the universe? typical particles, but are heavier. “We If resources were unlimited, would haven’t seen them yet, because we we be able to get all the answers to the haven’t yet achieved high enough en­ big questions about the universe and the emergence of life on our planet, or are there other objective - human - limitations? “There are definitely ways in which we could make progress if we had in- finite resources. Would we be able to answer all the questions? I don’t have an answer to that.”