Wolfgang Ketterle, 2001 Nobel Prize in Physics - Press Conference

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PRESENTER: Good morning. The announcement of the Nobel Prize going to our friend and colleague Wolfgang Ketterle and his colleagues comes like a bright ray of light into a very dark period for MIT, and for our nation and world. This is really a wonderful day for Wolfgang and his colleagues, it's a wonderful day for MIT, and it certainly is a wonderful day for physics and science in general. We're absolutely delighted. I would also like to say that this award reminds us once again of how incredibly important it is for our nation's universities to keep their doors and their campuses open to those wonderful people who come to the United States from many other nations around the world to build the tremendous intellectual and human community that we have.

But you're not here today to hear from me, you're here today to hear from our colleague, Wolfgang Ketterle, who's joined by professors Dave Pritchard, Dan Kleppner, and Tom Greytak. As you will hear, this has been a tremendous team effort, and has a long history here at MIT that has led up to this wonderful day for Wolfgang. So let me introduce the man of the hour, our colleague, Professor Wolfgang Ketterle.




KETTERLE: Thank you all for coming. It's an overwhelming experience, you know? There are many emotions. You're overjoyed, you are thrilled, you are scared, it's surreal. It's only slowly that I think reality sinks in. I mean, this is something really big, and it's a big distinction. And it's wonderful to celebrate it, and it's also wonderful that here in this room there are people who have greatly contributed to that, either my collaborators or people who have mentoring my career and have greatly supported me.

So it's a great moment for MIT, it's a great moment for atomic physics, it's a great moment for all of us. And I'm really grateful and proud for many, many people.

AUDIENCE: Could you say something about your colleagues at Colorado?

KETTERLE: Yes. This prize is shared with Eric Cornell and Carl Wieman at the University of Colorado. And we know each other very well, and since the early '90s we have been really racing towards colder temperatures and hunting for this new form of matter. It has been the best competition of my life. And it's just great to see that there is no loser, no winner. I mean, we have both shared the excitement and the thrill of a new field, and we all got [INAUDIBLE] cognition. So they have been wonderful colleagues, and they have done excellent and great work. And it's been exciting.

AUDIENCE: [INAUDIBLE] history represented by your colleagues?

KETTERLE: Yeah, actually the field of ultra-cold atoms has a long history. And a lot of pioneering work was done here at MIT. It started in the late 1970s with Tom Greytak and Dan Kleppner pursuing Bose-Einstein condensation atomic hydrogen. And it seemed that atomic hydrogen was really just unique, and no other atom would be suitable for that. But then came other people, among them Dave Pritchard, who pioneered laser cooling.

And that opened a new perspective. And eventually, it was the merger of both fields which led to the big breakthrough. And I really feel privileged that, when I joined MIT in the early '90s, that I was privileged to complete this work and accomplish the observation of Bose-Einstein condensation. But MIT has been really special. It's a 20-year-long tradition of atomic physics in pursuit of Bose-Einstein condensation which came to fruition. And it's sometimes embarrassing to see that I get recognized, but I think it's a recognition for all of us. And I'm proud to be part of MIT.

AUDIENCE: One other thing. Could you talk just a bit about explaining Bose-Einstein condensate to those of us who [INAUDIBLE]?



So, well, Bose-Einstein condensation is a new form of matter. It's a special form of matter which forms at the lowest temperatures ever achieved. But just to address you as lay people, you may wonder why can get physicists so excited about a little puff of gas in millimeter or sub-millimeter-sized cloud of almost nothing? But we get excited because it has special properties.

The sample consists of millions of atoms, and they all oscillate in lockstep. They sing in unison. It's a very special form of matter, which has very special properties. And by discovering and studying this form of matter, we learn more about nature. And I think this is the first [INAUDIBLE] for physicists if you discover a new form of matter, if you explore new properties. You have a deep look into the beauty of nature. And this is exciting.

Now, this form of matter, because it is so special, has widespread implications. And some of them may be in the applied area. So there is speculation that this form of matter may find uses for precision measurements, for better atomic clocks, for nanotechnology, maybe even for a novel form of quantum computation. But this is the job of my team and the other groups worldwide to explore that and figure out if that is possible. But it is typical for fundamental research that there is something which has a new quality, and then there are numerous possibilities which can be explored.

Maybe to give you an analogy, what has been accomplished with Bose-Einstein condensation is for atoms for material particles the same step which was taken for light when the laser was invented. You all know the difference between a light bulb and a laser beam. Until the discovery in '95 in atomic physics with atoms, we were in the era of light bulbs. We only had atomic light bulbs, atoms randomly moving. But all of a sudden, with a breakthrough in '95, we have now streams of atoms which have exactly the same properties as a laser.

All atoms move in lockstep, highly directional beams of atoms. So in some sense, we have repeated something with atoms what was accomplished with the optical laser some 30 years earlier. And I think it's fair to say that those developments have revolutionized atomic physics. It has changed the way how atomic physics is done now.

MODERATOR: Questions?

AUDIENCE: As a physicist, is it every physicist's goal to win the Nobel like it would be to win the Super Bowl for a football player?


KETTERLE: No, definitely not. We do physics for the excitement, we do physics for just being creative. And of course, we pick our research areas to have impact. But the Nobel Prize is something which is so extraordinary, we are not working for that. This is sort of something which, yeah, for just a few of us may come as icing on the cake. But we get our excitement and our satisfaction by doing good physics.

AUDIENCE: I have two questions. One is that you made this discovery of this new kind of matter in 1995. Was there something that happened between '95 and now, or were you awarded this recognition from what happened in 1995?

KETTERLE: I think the breakthrough was in '95. It was a new form of matter. But its impact could not be predicted at that point. And what has happened in the last six years is that numerous research groups and my own research group have exploited this new form of matter, and have shown that it has many special properties, that it can be used for many fundamental studies in physics. And people have also taken first steps to build matter wave sensors, new sensors with that. So the full impact, the breadth of this discovery, it took a few years for that to become visible.

AUDIENCE: When you talk about nanotechnology and some of the applications, could you give us a more solid example of what you think in the future will be possible, something that maybe would be used by a consumer? I'm not really sure, but or in the medical field, or is there something like that?

KETTERLE: I think every specific prediction will be proven false. And--


--that has actually happened to the field. People didn't predict what has happened in the last few years. But I don't want to dodge the question, but let me first be general. We have atoms now with a quality of laser light. Atoms are the basic building blocks of nature, and we now have unprecedented control over those building blocks of nature.

This must be good for anything. This must be good for many things we can't even think of. And what people are discussing is that you might now use atoms and deposit them on surfaces in fine patterns and create some nano devices of the future. Other people think that those atoms which oscillate in lockstep may eventually be the clockwork of novel computers.

But I want to stay vague because these are areas which are in exploration. And the future will tell what comes out of it. But these are the buzzwords, nanotechnology, new forms of computation, new atomic clocks. And that's what groups are working on.

KASTNER: There may be questions from the telephone. You could ask if there are questions from the telephone. Just ask if [INAUDIBLE]. Ask if there are questions from the telephone.

KETTERLE: Are there questions from the telephone?

AUDIENCE: They're typing.

AUDIENCE: This is Robert Lee [INAUDIBLE] from the Los Angeles Times. I wonder, sir, if you would expand a bit on the specific unusual properties of the condensate that you are today being honored for. I know you talked about the moving in lockstep, but I know that you've spent considerable time examining their broader properties. And I wonder if you could tell us a little bit about that, please.

KETTERLE: Yes. The Bose-Einstein condensate has some cousins. And those are superfluids and superconductors. You may be most familiar with superconductors, where electrical currents can flow without any dissipation. A superconducting wire does not heat up when carbon flows through that. And the Bose-Einstein condensate has similar properties that atoms can be in motion without friction, without slowing down.

So those properties-- superconductivity, superfluidity, they carry the word "super" because there's something special to it. And the Bose-Einstein condensate is the most fundamental example in this family of super states of matter. So it's coherence, absence of friction, superfluidity. These are more technical words, but these are the buzzwords which I would associate with very special properties.

AUDIENCE: This is [INAUDIBLE] from the Washington Post. Could you discuss your atomic laser a little bit, and tell me how you were able to direct the particles at a target?

KETTERLE: OK, the question is about the atom laser, how we direct particles and how we created it. When the Bose condensate was discovered in '95, people saw that it was an ultra-cold cloud of atoms, but people hadn't shown directly that those atoms clearly march in lockstep. And this is the most important property of a laser, that it is one big wave. In the case of light, it's one big electromagnetic wave. In the case of atoms, it's one giant matter wave.

And when we realized the atom laser, we were able to show just that. We could show that the atoms in the Bose condensate are really wave-like. And secondly, we could create the first rudimentary atom laser by having atoms dripping out of the condensate. They were accelerated by gravity and formed the first coherent atomic beams, again an analogy with laser beams, which are coherent beams of light. Since then, other groups have shown how you can create more directional atom lasers, most notably the group of Bill Phillips at Gaithersburg. He was a Nobel laureate for laser cooling four years ago.

AUDIENCE: I have a few more questions. What is your next step with your research, and what are you going to do with the money?


KETTERLE: The next step in the research is to use the Bose condensate to test fundamental physics, to realize more different and more subtle new forms of matter. We also have experiments where we try to put both condensates on chips, on micro fabricated surfaces. So there is some hope that we can create, in the future, atom chips where, you know, in ordinary chips, the information is carried by electrons moving in wires. And now we want to create atom chips where atoms move close to a surface and are guided around. So we're talking about a next major step, and new perspectives to the field.

I haven't thought what I'm doing with the money. I mean, I have a family, and so there are many good uses. But I have not spent any second to think about it.

AUDIENCE: [INAUDIBLE] I have two questions. First of all, where were you when you got the call winning the prize? And second of all, you touched on this a little, but all of you are very young and [INAUDIBLE] after the research significance has had a chance to sink in. What do you think it is about your research that has made the physics community immediately recognize its importance?

KETTERLE: OK, the first question is where was I when I was notified about the prize. I was in the bed. I was sleeping. And it was 5:30 in the morning, and the phone rang. And it was Professor [? Norbi, ?] the Secretary of the Swedish Academy of Sciences, who told me he has some important news to tell me.


And then he informed me that I am the co-recipient of this year's Nobel Prize. The other question was that we are fairly young. Yeah, it's probably rather unusual that research is recognized just a few years after the discovery. But I think this reflects that many colleagues worldwide were immediately picking up on those developments. And I estimate that, since '95, 2,000 scientific research papers have been written on the subject, which is really a lot.

So worldwide, the activities of hundreds of scientists. And I think this just showed that this research had impact. It has revolutionized atomic physics. So researchers vote with their time. And many of my colleagues have voted that this is important, and that this is promising for further exploration and developments.

MODERATOR: Are there questions from the floor? Are there questions from the telephone group?

AUDIENCE: I guess i just want to clarify that one thing you're saying about the atoms on the chips. Does that mean possibly, as I've read-- and I can't believe everything I've read-- that you're talking about the faster computers? Is that what you?

KETTERLE: Faster computers. Well, this research is about ultra-cold atoms. And ultra-cold means that the atoms are very slow. So we won't have an advantage in speed because atoms are moving sort of like a lightning bolt. But there's some hope to use the coherence of atoms for a new way of computation. So quantum computers are not necessarily faster in terms of their clock speed, they're just much more efficient. They do parallel processing. It's a heavy parallelism, which makes them win big in that regard.

But if atom chips will lead to this new class of quantum computers remains to be seen. This area of atom chips is really in its infancy. But it's a promising direction to pursue.

AUDIENCE: Professor, can you explain just how cold [INAUDIBLE]?

KETTERLE: OK. Bose-Einstein condensates are characterized by temperatures in the nanokelvin regime. This is more than a million times colder than interstellar space. So sometimes, I mean, you can say why is it not cold enough to be 1,000 times colder than interstellar space. So well, there are phenomena in physics and novel properties of matter which require to go even colder. And so it was only when we had developed techniques to cool more than a million times lower than the temperature of interstellar space that we could observe this new form of matter.

AUDIENCE: And were the experiments actually carried out at labs here at MIT, or in both?

KETTERLE: They were carried out in both labs. There were independent efforts at Boulder using rubidium atoms, at MIT using sodium atoms. We were feverishly working on those experiments for several years. And it was sort of remarkable that, within a few months, both groups succeeded. It was in June that they had the breakthrough in Boulder, and in September when the breakthrough at MIT happened.

MODERATOR: I want to add that there were a number of other Nobel Prize winners here in the room to celebrate. And I wanted to invite them to come up to join Wolfgang. Sam Ting. Professor Sam Ting.

AUDIENCE: Dr. Ketterle, I wondered if you would--



MODERATOR: Gary [? Friedman. ?] And anyone else.





MODERATOR: The left to right on this is Ting, Ketterle, Friedman, and Sharp.

AUDIENCE: But don't stop smiling [INAUDIBLE].


MODERATOR: And I also want to bring in the students who worked with Wolfgang Ketterle on this project, who are waiting in the wings.


MODERATOR: Dan is the head of the [INAUDIBLE] lab of electronics, which has sponsored much of Wolfgang's research. Would you like to say a few words? Daniel Kleppner.

KLEPPNER: I'm not the director of [? Areli. ?] That's [? Irwin ?] Shapiro, who is here. And it's a wonderful day for me personally, and I think for my colleagues, because we have watched Wolfgang's work since he came to MIT, and admired so much how he went about his work, his taste, his goal, his enthusiasm. He's a marvelous colleague, and his accomplishment certainly deserves the prize. We're very pleased that he has it because there are many accomplishments in science which deserve the prize but don't get it. And in this case, we have a success story where the work really deserves the prize and does get it.

I'm particularly happy today because I've had a long association with the subject. Tom Greytak and I many years ago were among the first groups to start searching for Bose-Einstein condensation in an atomic gas. I knew nothing about it at all before Tom explained to me what Bose-Einstein condensation was. And he explained it to me, and it sounded kind of interesting. So it was really through his stimulation that we started out in this work many years ago.

And eventually, we did get it. But we started very soon, and we pursued the only method open at the time, which was with atomic hydrogen. Later, when laser cooling was invented and created, it turned out that it works much better with the alkali metal atoms. Nonetheless, we did get it. And that was a great satisfaction to us.

But I think what is even more of a satisfaction is that this field has grown so remarkably and had such an impact on so many scientists. And I take a personal satisfaction not only because of the work that Tom Greytak and I, the early work that we did, which is a prelude to this, but because of the people involved with it. The Scientific American dubbed me the grandfather of BEC. Well, grandfathers can be very happy people.


And I think I'm the grandfather because Dave Pritchard was my student, and he brought in Wolfgang and mentored his career. So I'd say Dave Pritchard then is the father [INAUDIBLE] grandfather. And Tom Greytak was not a student of mine. He's a brother. So let me [INAUDIBLE].

MODERATOR: While we're talking about family matters, we have family that matters to Wolfgang here, his two sons. And I just want them to come up, and he can introduce them.


KETTERLE: So well, I have three children, and they are all different. My daughter told me this morning she wanted to go to school.


Holger made already a memo. My daughter, she's 12 years old. Holger is nine years old. And Holger, he made a [INAUDIBLE] to one of the reporters. He said, the best thing about my dad winning the Nobel Prize is I don't have to go to school today.


And this is Jonas. He's 15 years old, and he's at Brookline High School. But getting more personal, I also ask Dave Pritchard to stand up and come next to me, because it really speaks for how the MIT system worked. He hired me as a postdoc in 1990. I was in a different field of physics, and he was in the cold atom field. He hired me as a postdoc, and I learned from him.

And after three years of being a postdoc, he said, so well, I've taught you many things, but now you can take my lab and be on your own. And two years later, we discovered Bose-Einstein condensation. And it was sort of executing a common agenda. Some person on the phone commented on my young age, but there's also the wisdom of an older person [INAUDIBLE].


PRITCHARD: Well, you know, when Wolfgang was my postdoc, we came up with an idea that was a modification of a trap that I'd co-invented earlier. And this idea enabled us-- it was called a dark spot [INAUDIBLE], a dark spot trap, and it enabled us to hide lots of the cold atoms in the middle, in a dark spot where the laser light didn't shine, actually. And the rest of the atoms were pushed in by more laser light.

And the result of this was that we had gotten to a density of atoms where it was apparent that if we got really the vaccum a little bit better, we could begin to get much colder by using the technique that Harold Hess and Dan Kleppner and Tom Greytak had developed called evaporative cooling. That's very simple. It's just the way you cool your coffee. You let the hottest molecules escape, and then the ones that are left behind are cold.

Unfortunately, that doesn't work in a very dilute gas. You need to have lots of collisions. And so people have always come up to me and said, Dave, you know, what a sacrifice you made by giving up this experiment, you know, just when it was on the brink of more progress. And to me, it was a really obvious and pleasurable, and in fact this today makes it even more pleasurable to have done that, because what I got for giving up one of my three experiments-- and the other two then went better because I could work on them-- was a wonderful colleague.

I just can't explain to you how much fun it was to work with Wolfgang then as a postdoc, and now that we're doing some new things with making atom interferometers on a chip and so forth. And I mean, let's face it, the experiment went a heck of a lot better with him running it than with me.


And so I thought it was an easy call, and especially to get another addition to the atomic physics group here. It's been worth it. And we're just so happy he stayed.


MODERATOR: We also do teaching at MIT, and the cutting edge this represents is part of that. I want to introduce Marc Kastner, the department head of physics, who's going to talk a little bit about Wolfgang's teaching.

KASTNER: Wolfgang is one of our most dedicated, passionate teachers. He's a superb educator of graduate students. We're going to bring his students up in a minute. He's a superb classroom teacher at the undergraduate level. This summer, he even took a high school student into his lab to excite him about research.

I think he's the perfect example of what a faculty member ought to be at a research university, someone who does cutting-edge research and brings the excitement of that research to the students. And so just on behalf of the department, I want to thank you for everything you do, Wolfgang.


KETTERLE: But I think it's really time that all the people who currently work with me just come up and join this moment with me.



MODERATOR: [INAUDIBLE] Nobel scientist.

KETTERLE: I could introduce everybody individually and tout his accomplishments, but this is a fantastic team. And accomplishment in science really require to work with a team. I mean, the people who stand behind me also speak for this explosive growth in the field. When the research was initiated, it was just myself and two graduate student, or sorry, three graduate students. And then the team was growing.

Right now, we have a major effort in different laps just to explore all those new possibilities. But I really want to give a big hand to this team. They are really carrying on this exciting research.


I was just asked I should give the names. There's Todd [? Gustavson, ?] [INAUDIBLE], [INAUDIBLE], [INAUDIBLE], Dave [? Kipinski, ?] [INAUDIBLE] [? Campbell, ?] [INAUDIBLE] [? Chin, ?] [? Sharmila ?] [INAUDIBLE], [? Michael ?] [? Boyd, ?] [INAUDIBLE], [? Johnny ?] [? Bogles, ?] Jake Harris-- sorry-- that's when you go to bed at two o'clock and you are woken up.


At 6 o'clock, there's [? Dominic ?] [INAUDIBLE], there's [INAUDIBLE], there's [INAUDIBLE], [INAUDIBLE] [? Gupta, ?] and [? Yong ?] [INAUDIBLE], and [? Eric ?] [? Street. ?] Sorry, [? Dominic. ?] It's a blackout which just happens.


MODERATOR: Are there are any other questions from the press, either on the phone or here?

AUDIENCE: I have one question if we have [INAUDIBLE]. I wonder, sir, if, on the occasion of the centennial Nobel Prize, you might reflect for us on the relationship between the Nobel Prize and the pursuit of excellence in science.

KETTERLE: So well, I mean the question is about the centennial of the Nobel Prize. I think it's so special to win the Nobel Prize, nothing can top it. So the fact that it's the 100th anniversary, it makes it-- does it make it even more special? I think it's so special that nothing can top it. But I think 100 years is a long tradition. And I think for all of those 100 years, the Nobel Prize has really distinguished great science. And it shows that science is exciting, and has not lost any of its excitement in the past 100 years.