With George F. Smoot Interviewer: Naoshi Sugiyama

IPMU Interview with George F. Smoot Interviewer: Naoshi Sugiyama

IPMU is a wonderful place to Paul. They were telling me come and work about Verlinde’s paper. I said Sugiyama: Shall we begin the we should have a journal interview for the IPMU News? club on it. So I put together Smoot: Okay, yesterday we an impromptu journal club posted our rst IPMU paper, and we made it through two- which I wrote with Damien thirds of the paper. The next Easson and Paul Frampton. It day at tea in Piazza Fujiwara, I is titled“ Entropic Accelerating said that what we should do Universe.” We are saying that is to create a model where the reason why the universe is we explain dark energy as an accelerating is because of the emergent force, just as some entropy screen at the horizon, people try to explain gravity as and if you increase the an emergent force. We should horizon, it makes the derive dark energy that way. entropy increase, Then Paul said“, We should so you get an write a paper right away.” So outward force TdS/dr he started writing. I added my on the horizon. This is just as section. It’s all sort of hand good as Lambda. waving but it is my rst IPMU An interesting thing about paper. It came from lunch and it is that the rst time I went tea together. I image that it is to lunch and met Damien, an interesting story for IPMU. I then went to tea and met Sugiyama: What is important for IPMU is maximum interaction among people, George F. Smoot is Professor of and this is one of the best Physics and Director of Berkeley Center for Cosmological Physics at examples. How do you nd the University of California, Berkeley. IPMU? He is also Director of Institute for the Early Universe at Ewha Womans Smoot: I really like IPMU; University in Korea since December it’s very big and impressive. 2008, and Professor of Physics at Université Paris Diderot - Paris 7 since What’s really impressive is 2010. He was awarded the 2006 how quickly it has grown to Nobel Prize in Physics with John C. Mather for“ their discovery of the international stature. It seems blackbody form and anisotropy of like a wonderful place to come the cosmic microwave background radiation.” Among many other and work and I really like the distinguished awards, he received idea of Piazza Fujiwara. the Albert Einstein Medal in 2003 and Oersted Medal in 2009. Also, yesterday I met an

12 IPMU News No. 9 March 2010 IPMU Interview ofcer from MEXT. I said the way in showing how you how IPMU is a good model can put these things together. with George F. Smoot and how it builds a good In Korea, we had the same foundation. One of the things sort of idea. We have all the Interviewer: Naoshi Sugiyama that I told him I thought was researchers and ofces on one very important was public oor all around the periphery relations, both to talk to the and there is an interaction area public and to get their support, in the middle. It’s all glass walls, but also to encourage young partly frosted. You can write Japanese to become scientists. on them like blackboards. A couple of days ago I gave So it’s a similar idea but on a a lecture at Kyoto University. much smaller scale than IPMU. After my talk, I had dinner Sugiyama: Which elds? with some of the professors Smoot: That’s the Institute and I was asking them“ Why for the Early Universe, so it’s a did you become physicists.” partner to IPMU, but a small The rst one said“, When I partner, one-tenth the size of was a young boy, Yukawa IPMU, with a much smaller got the Nobel Prize.” Three of budget. We can’t offer higher them in a row said the same salaries because they are set thing. Almost all of them were by the universities. We have inuenced very much by the 10 faculty, two more positions, fact that Hideki Yukawa was and 10 postdoctoral fellows. so valued by Japan. So they That is a signicant number, dreamed of being similarly but not compared to IPMU. valued and that encouraged IPMU is clearly bigger and it’s them to go and do the same. clearly more international. Sugiyama: So you are the right Sugiyama: Are you able to person to guide young people attract people from abroad? to cosmology. Smoot: There’s a lot of encouragement for that. Institute for the Early About half of the people are Universe is a partner to IPMU Koreans and half are from Smoot: Well, I am encouraging overseas. But IPMU is extremely them but I also think there are successful and I think part of many other interesting elds. the reason is that Hitoshi has One of the things I spoke been very active and part of about with the MEXT ofcial, it is that they actually offer who was talking about setting enough money that you can up another WPI, was that the live reasonably. The good thing good thing about IPMU is that is that most places can’t afford it is bringing together people to do that, but the IPMU from multiple disciplines. When realizes that it has foreign Interview you move into something visitors, and has found nice like energy and climate or

synthetic biology, you need Naoshi Sugiyama is a principal people from very different investigator of IPMU. He is also Professor of Physics at Graduate disciplines. IPMU is leading School of Science, Nagoya University.

13 places for accommodation colleagues in France. They told Gamma Ray Telescope, which developed that technology, like this one, and has found me to tell Hitoshi that they had only just become feasible, and then we discovered the good subsidies for that. It is would like to build ties from and one of the ideas was to dipole anisotropy (which is attractive for people to come France with IPMU. The French try to measure neutrino mass caused by the Earth’s motion here. It’s interesting to be in are very interested. by measuring the end point relative to the CMB, and is Japan anyway. Because it’s of the beta decay spectrum, not of cosmological origin) such a big place, and has so How did the COBE-DMR which some people did. The from the U2. We got better many researchers and visitors, start? other idea that we came limits on the intrinsic CMB it’s attractive to come there to Sugiyama: So you are across was using cosmic anisotropy, but we decided to meet many people. I’ve met impressed with IPMU; that is microwave background (CMB) make a balloon experiment to people from CERN, from the good news for us. Now let me to see what the large general improve it with a cool version United States, from China and get into some history. When structure of the universe of differential microwave from Japan, many different and how did you start the looked like, not so much the receivers. We needed to move sets of people. There are a lot COBE-DMR (Differential large-scale matter structure but to higher frequency to keep of people, and lots of talks. Microwave Radiometers) team? the geometry and temperature the system compact and, as There are so many talks in fact, Smoot: Well, rst I was of the universe. I thought that a result, needed to be higher that I can’t go to all of them. doing early experiments in would be a really good thing in the atmosphere to avoid Sugiyama: Right, IPMU has the cosmology, such as looking to to do. We obtained some seed atmospheric uctuations. We potential to be an international see if there was antimatter in money and we built a little went from 1 cm to 3 mm and research hub. That’s really the universe, including cosmic radio receiver and tested it out we got much tighter limits important. ray balloon experiments where on the rooftops and then up which was getting to the point Smoot: Yes, it clearly is doing we looked for anti-atoms and on the high mountains and where you needed dark matter that. Right now it is very strong anti-nuclei. We also did some saw where we could do it. to make the structure. in theory but Hitoshi is moving gamma ray observations. Then Then we said“, Well, we have But even before the balloon, to observations with Subaru I thought of a new way, a to y in the balloon.” I put in a proposal to NASA. and Hyper Suprime-Cam. better way to do experiments Sugiyama: When was this? This was towards the end of That’s the same thing we’re and I went to Luis Alvarez Smoot: This was the 70s. the 70s, when there was a big trying to do in Korea. We just who was overall head of that Then we had the idea of call for proposals for satellites. signed an agreement to be sort of area. There were four ying in the U2, which was It turned out that a group from involved in BigBOSS. of us postdocs. He said“, Well good because it would bring Princeton, MIT and Goddard Sugiyama: Do you have any before you go on to the next your equipment right back Space Flight Centre, and then advice for IPMU? experiment, what all of you to you; it didn’t crash like the also a group from the Jet Smoot: No, I think IPMU is should do is to consider that balloon. We couldn’t get a Propulsion Laboratory (JPL) doing extremely well, and it your idea is just one of many lot of balloon ights because put in a proposal. My proposal should encourage overseas ideas. You should also look there would always be some was to use the DMR to map researchers to come and visit and see what else is possible, damage to it, and we had to the sky, the JPL proposal was as much as possible. what has been discovered, x it up to y again the next to use a different kind of fast Sugiyama: Do you feel that what new technologies are season. We ew twice a year scanning method to map whenever you meet people out there, and what new ideas if we were lucky; once a year the sky, and the Goddard, somewhere else, you can are there because there’s was typical. But we wanted Princeton, and MIT proposal recommend that they visit something else you can do.” to cover a lot of the sky. was primarily to measure IPMU? And he said“, I recommend With an airplane, we could the absolute temperature; Smoot: I have encouraged my you all take a month or two go repeatedly. We wrote a they also had a sky mapping postdoctoral fellows to come. out and study and see what proposal and eventually got one based on the Princeton Three already have, and there else you might do.” it approved, and we built experiment. All three of them are probably another two or So we did a survey and what’s known as a differential passed through the rst cut, three who are going to come one of the things we thought microwave radiometer, looking but the JPL and my proposals this year. And I talked to my about was a Compton at the two differences. We were for a small satellite while

14 IPMU News No. 9 March 2010 the other one was for a big idea for a scientically good Washington D.C. We had a could determine Omega this satellite because it had all sort design. You have to say what series of talks, and when that and that, even though I knew of stuff in it, and it got merged you are trying to measure and was done, we held a press you could do it a little bit from with IRAS at the time. Then what your primary science conference. Then there was the spectrum. IRAS got into trouble and goals are. Then you have a set so much press coverage, an Sugiyama: This is what kicked them off. We made of requirements you get from unbelievable volume. Hitoshi we have actually done in presentations. The outcome, that, and then you have to can tell you about that, Berkeley. One nal question: however, was not clear and we make an instrument that fulls because he had just nished how do you see the future of were not sure whether they those requirements and can graduate school in 1991, and cosmology? Which direction were going to pick us or call measure them. It was having then he came to Berkeley, should we be taking? for a merger. But it was clear clarity about what to do and probably because of COBE. Smoot: I think that we we rated a little more highly the experience about what to Sugiyama: Well that’s the have gotten to where we than JPL did at the time. do, and then having people same for me. I went to have a good macroscopic When they kicked the who work together well and Berkeley in 1993, one year understanding of the universe. CMB part of the stuff off effectively. after COBE. We have some idea of the of IRAS, they said“, Well we Smoot: And then we were general sweep. We are will just create a merger Exciting science proceeds going to MAX and MAXIMA trying to put together all the and call it COBE and put it very quickly to try to look for the rst observations and all of our behind.” So we got put in the Sugiyama: What did you feel acoustic peak, which is what understandings, and to see queue later. My design won when you found the CMB WMAP was designed to if it adds up to the plan as among the presentations, uctuations? measure very well. But in fact we see it. It requires people and so I became the principal Smoot: Well I wrote about it in acoustic peaks were scooped who understand astrophysics, investigator of the team for a book. When we found them well before it, even though people who understand anisotropy experiment. And so many people wanted to it was quickly going on. You cosmology, people who for the spectrum experiment, rush and analyze them quickly. have to realize that exciting understand particle physics, John Mather’s design was the We wanted to see what it was. science proceeds very quickly. and people who know how to winner. Then one of the other I was crying“ No, rst we have It was very amazing, kind do big simulations. You need missions kicked off from IRAS to keep everybody on the team of exhilarating around that people who know the different was added. Anyway three PIs focused on showing whether time, but also very exhausting stages of the universe, who were designated and formed this is valid or not, because as because we were writing know the mathematics, who teams. That’s how the whole soon as you say it’s real you the papers and checking know the computer stuff, and sequence started, after we had quit looking to see if there are everything and getting it all who know how to interpret stopped, looked around for any systematic effects.” I had right. the experiments to really test an exciting new eld, come to keep everybody thinking Sugiyama: But I envy you, the models and see what’s up with the scheme to make “It could be a mistake. Let’s because this is kind of like a going on. I think IPMU is the measurements, built the check.” I didn’t want the many dream come true. well positioned for the new prototype, learned how to do people on the team who Smoot: Right, most people stage. IPMU provides the it, and then put a proposal in were doing the hard work of didn’t really understand what it cross-section of people, but that won. checking the errors to look meant, and in fact if you look you need to be attacking the Sugiyama: I see. So do you over and see their colleagues at the theoretical papers back fundamental problems of think the key success of COBE doing data analysis and having then, the idea that you could cosmology. is because of the technology or fun. I wanted everybody to discover the cosmological Sugiyama: That is a nice rather the scientic concepts? share equally. parameters from it was really conclusion. Thank you. Interview Smoot: I think it was a mix. In April 23, 1992, the COBE quite new. We were able to We had the ideas. I had some team announced the discovery learn some things, but it wasn’t people who worked together of the CMB anisotropy at until a year later, in 1993- well and very effectively. This the annual meeting of the 1994, that you rst started was because I might have an American Physical Society in seeing papers saying how you