|Photo Credit: Yasmin Hankel|
What brought you to physics to begin with?
I don’t have any unusual story about what led me to physics. Like most physicists, I was always very curious about things. I always liked science, and I seemed to be pretty good at it. In high school, I took physics, and I absolutely loved it. I remember telling my high school physics teacher that I wanted to major in physics. He told me no. He said, “You shouldn't do physics because there is nothing left to learn. You should be an engineer, because we’re always inventing new uses for physics, but the actual physics has already been learned.” It was well-intentioned. He was a great guy, and he was very supportive of me, but I think he genuinely thought that there was nothing left to learn.
When your high school physics teacher tells you this, you just accept it as the truth. I actually started college as an electrical engineering student. I didn’t like it, I was bad at it, and it didn’t work out. During the first summer after my freshman year of college, I worked at NASA's Jet Propulsion Laboratory in Pasadena, and I was around physics students for the first time. It was so clear that this is what I should be doing. It was like for the first time people understood me, and so on my first day of sophomore year, I went into the Dean’s office and transferred into physics.
"It was so clear that [physics] is what I should be doing. It was like for the first time people understood me. . ."
Where were you an undergraduate?
At Duke, in North Carolina.
So, then in leaving Duke, you went to Columbia?
I went to Columbia, that’s right.
For my senior thesis at Duke, I worked with Ronen Plesser, a string theorist, studying holography. The idea of holography as it applied to quantum gravity had just come out a year before. Leonard Susskind had come up with this great analogy for how holography works with black holes, and about how you can’t hide a black hole. I’m sure you’re familiar with the idea that even though we appear to live in a three-dimensional world, there is some clever way of encoding all this information in a two-dimensional surface. You can take the information encoded on the surface of a black hole and encode it onto a screen, and you might say, “Okay, I’m going to hide a second black hole behind the first one.” But, it turns out, the null geodesics, if you actually work them out, don’t let you do that. It turns out that all the information that you’re trying to hide still shows up on the screen. He had drawn this kind of schematic illustration of this and so my senior thesis was working out on a computer exactly what happens when you try to hide a black hole. It was a great way to learn GR – working out the null geodesics to demonstrate holography.
So, by calculating the null geodesics you can see how you would extract the information there? By probing the black hole, by sending light in and seeing how it comes out?
Precisely. That’s the way that Susskind suggested information gets encoded. You take the null geodesics that connect a point on the black hole horizon to a screen at infinity. This is the map between the two, and I just worked it out for a two black hole case.
I worked with Ronen Plesser and he introduced me to Brian Greene at Columbia, who I had never heard of before. I started at Columbia, intending to work for Brian Greene, and he had just come out with his book, The Elegant Universe. It was fun that, just as I start, I’m working for this professor who is suddenly pretty well known. Brian was my advisor. I did my thesis in superstring cosmology, in particular the Brandenberger-Vafa mechanism.
String theory demands that there be ten dimensions, and we only see three space at one time, so six are missing. The usual explanation is that these six must be very small; that’s why we don’t see them. But there’s no explanation given for why they’re small. Why is it that three special dimensions are big and six are small? Why aren’t they all big, or all small, or some other combination? And there’s nothing suggested except one idea proposed by Brandenberger and Vafa that had to do with string winding.
So, unlike a point particle, a string can actually wind around a dimension. It’s the opposite of a Kaluza-Klein mode, because the energy of a Kaluza-Klein state goes as 1/R where R is the size of the dimension.
Just like a particle in a box.
Winding modes sort of behave the opposite way, as you might guess, from the fact that the energy of the string is proportional to its length. It’s the tension of the string. So, Kaluza-Klien modes and winding modes are sort of opposites. As you change the size of extra dimensions, the energy of Kaluza-Klein modes go as 1/R. So, as you make the dimension big, the energy of a single Kaluza-Klein state becomes small. The energy for the other goes as R. Brandenberger and Vafa pointed out the natural beginning state of the universe would actually be where all nine spatial dimensions are very small, about a string length, with radius of one in string units. This would allow for sort of a gas, a thermal ensemble, of both Kaluza-Klein and winding modes. This means that the size of the universe would sort of oscillate around the value one because the Kaluza-Klein states would exert a pressure, keeping it from getting too small, and it can’t get too much bigger because the winding modes would keep it from expanding.
It oscillates around this, unless some of the strings annihilate. Just like a positron and electron annihilate, you have a particle with a plus one and a minus one and they annihilate, so these winding modes are also charged. So, if it’s wound one way, that’s a plus one, and if it’s wound another way, that’s a minus one. So, if these winding modes meet and interact and unwind, then they go away, and the universe can expand. If all the winding modes go away, then finally the universe can become big. And so, you then ask, “How likely is it that these strings would meet and interact?” And then it suddenly becomes clearer that having three large spatial dimensions is very special. And the reason for this is because, if you have a plane, you can put two lines in that plane. And those two lines will usually intersect at some point. But if you put two lines in a 3D space, those lines will probably not intersect. It’s like 1+1=2. Two one-dimensional objects will usually meet in a two-dimensional space, but they will usually not meet in a three-dimensional space. Now these wound strings, they move in time, so they sweep out a two-dimensional worldsheet. And so, if you think about how likely is it that wound strings will interact in a 3+1 universe, they will usually interact at some point in space, at some point in time. But they will probably not interact if it were 4+1 dimensions and higher.
So, we have two lines in a plane. Each is a one-dimensional object and we’re putting them in a two-dimensional space. 1+1=2. But they will usually miss if it were a three-dimensional space or higher. It’s completely analogous if you think about a winding string, so it has a length, and it’s moving in time, so it has a two-dimensional worldsheet.
So, in three-dimensions, worldsheets will intersect, but in four dimensions they won’t.
In 3+1 they’ll usually intersect, but in 4+1 or more they won’t. If any more than three spatial dimensions became big, strings would not meet and interact and unwind. So the idea is that all dimensions were small, and then they were able to cut each other up until three dimensions became big, and then they stopped.
". . .the idea is sort of that all dimensions were small, and then they were able to cut each other up until three dimensions became big, and then they stopped."
This was the idea. Literally, the only equation was 2+2=4. It was a very clever idea, but no one had followed up on it, and my thesis was working out the details of this. I would love to say that we showed that this works, but it actually was the opposite. We showed it doesn’t work for the following reason: this dimensional counting of strings generically interacted in 3+1. It relies upon the idea that if the strings meet, like this, that they will interact, and that’s not true, because, in quantum physics, everything has a probability. We’re computing scattering amplitudes and cross sections. If this were a classical process, it would work. If classical cosmic strings meet like this, they will always reconnect. But because these are quantum strings, it’s just some scattering amplitude, and the scattering amplitude has a coupling constant out front. And in string theory, a coupling constant is not a constant; it’s a dilaton, a field. And this field is coupled to the amount of energy in the box, in the universe, and it turns out that when you work through the equations of motion, the coupling constant sharply decreases to zero, even if it started out strong. What happens is the strings look like they approach each other, but then they just pass through each other.
Q: Why is the coupling constant getting so weak and stopping this from happening?
The coupling constant is a field called the dilaton in string theory. It’s in all the string theories and it’s coupled to the total amount of energy in the universe. You can’t get rid of the field. A lot of times we just set it to a fixed value and kind of call it a day. But to really do this right, you have to let the field evolve, and it turns out that because you have all this energy and pressure in the box, the dilaton does have to evolve. It will quickly drop to zero. That is what the universe wants to do. It wants to make the coupling close to zero. So we ran a bunch of simulations and once in a while there was a case where it did happen to work, and three dimensions did happen to become large, but it’s not generic. And the beauty of their idea – it is still a fantastic idea – was that it did generically predict the large dimensions. Unfortunately that no longer seemed to be the case. My thesis was checking this detail.
That must have been a lot of fun, to be grappling with such deep questions about why there are three large spatial dimensions.
Having extra dimensions is one of the things intrinsic to string theory, but not many people wonder why is it broken up like this. People just assume that the six dimensions are small and then do whatever they’re going to do. So, it was a fun little niche problem. Unfortunately, I think we still don’t know the answer.
Well, that goes with the territory of working on such challenging issues. Were you ever deterred by the discomfort of the possibility of not making progress? If so, how did you deal with that?
I remember in graduate school when I told physics friends that I wanted to do string theory, a lot of them remarked, “Well, it’s so theoretical, it might not have anything to do with reality.” And those were good points. But the reason I wanted to do it was the following: if you look at the history of science, there have definitely been a lot of good ideas that turned out to be wrong. Some people, they get a good idea, and at first it seems promising, but then the more you work on it, the less promising it seems. And there are plenty of examples of that. But string theory is unusual in that the more we learn about it, the more right it seems, because there are a lot of places where it could have gone wrong, and it doesn’t. And so, yes, I was gambling my career on the fact that string theory was right, but it seemed like a good gamble. And if string theory did turn out to be wrong, it would be fascinating to see why it was wrong.
"Some people, they get a good idea, and at first it seems promising, but then the more you work on it, the less promising it seems. And there are plenty of examples of that. But string theory is unusual in that the more we learn about it, the more right it seems, because there are a lot of places where it could have gone wrong, and it doesn’t."
Q: I know that there’s a connection between classical theory on one hand and then a different number of dimensions and quantum theory, which is just mind-blowing.
Precisely, and that’s what everyone thought. It was 't Hooft who first pointed out this aspect of holography. You start with a quantum theory in five dimensions, and this was equivalent to a non-gravitational theory in four dimensions.
So, not classical versus quantum, but gravity and non-gravity.
It was Maldacena who first worked out this example involving black holes, and D branes and such for string theory, so it was an explicit example for people to study. And it was fascinating because there are two different sides to it, and people could do calculations on each side and compare notes. It turned out it was right. But, the amazing thing was, shortly after this, people starting using this tool to do calculations where you could actually do experiments. This was something people didn’t think we would have.
The first one I heard about was an experiment at the Relativistic Heavy Ion Collider (RHIC). I don’t remember the exact quantity that they were trying to calculate, but they could use these tools coming from string theory to calculate something that people could actually measure in a laboratory. It actually was right. Attempts to calculate this had completely failed using conventional means. This has since been refined. Even if the world doesn’t turn out to be stringy, it has still shown itself to be a very useful calculation tool. A colleague of mine once commented that he thought of string theory like imaginary numbers. Imaginary numbers have been very useful in calculating solutions to math problems. Are imaginary numbers real? I don’t know. But they’re sure as hell useful.
In any case, I still think it was a good choice for something to study.
Let’s move ahead to your decision to leave academic physics and do what you’re doing now. Tell me about this process.
I was a post-doctoral researcher for ten years, and as the years went by, I came to realize that the biggest problem in our community is not a technical one. It’s getting the public to understand what we’re doing and become supportive of it.
There were so many times that I’d be at a party and tell people that I’m a physicist, and they’d usually have two reactions. One reaction was, “Oh that’s awesome, that’s so cool. I’ve always wanted to meet a physicist.” It was like I had told them I was a unicorn. Like, "I’ve heard about those, but I’ve never met them. I didn’t think they really existed." And they were so curious, and they had all these questions for me. They had read books or seen TV shows, but they loved engaging with a real physicist because they hadn’t had a chance to really be involved at all. The second reaction was: “I don’t even know what to ask you. Why would anyone do that? What is it good for? Totally alien. I got a C in that in high school.” Part of the public is already very enthusiastic, but there’s no opportunity for them to be directly involved in what’s happening in physics. They might read a headline about the Higgs boson or something, but they don’t really know what goes on behind the scenes. The other part of the public is not understanding what we do; we’re not communicating to them why the work is important. These two observations actually point to the same solution.
"Part of the public is already very enthusiastic, but there’s no opportunity for them to be directly involved in what’s happening in physics."
There should be some way for the public to be involved. And, of course, there’s already books and TV shows and such, but this doesn’t let the public actually take part in the physics. These were things that were in the back of my mind as years went by. About a year ago, I realized that research no longer completed me. I felt like there was more to me than simply solving equations eighteen hours a day, and that I would like to be involved with other things in the world. I was in Paris at the time, and the University of Paris had recently allowed for private donations. Up until then, it was completely state-supported. I started helping our group out with fundraising, and I actually enjoyed it quite a bit. But it also occurred to me that conventional fundraising is a little bit limited to networking at cocktail parties by people whose circumstances allowed them to make a large donation. And so this led me to the idea that there should be a way for more people to be involved.
Someone wouldn’t think twice about paying $25 to see a science fiction movie, and they would think that was really neat. This gives them the opportunity to make a donation of, say, $25 to help a researcher actually study black holes. The next time they see a headline about a new particle’s discovery, or that a student has discovered a new comet, or some new discovery about the big bang, they’ll not only think it’s neat that scientists did that, but they’ll be a part of it.
We are building upon the success of crowdfunding. We are using accessible educational content to help people understand the value of supporting physics.
When was this?
It was late January when I decided to do this, so I’ve been working on it for about six months.
In leaving academic physics for the broader world, have there been things you’ve learned that kind of surprised you, where you thought X, but it’s Y?
Very many. In academia, as a researcher in theoretical physics, I didn’t really have to interact with non-physicists. My job consisted entirely of working with other physicists and writing articles and publishing them for other physicists to read. And, of course, I occasionally made public presentations and such, but that wasn’t my job. That was just a fun thing on the side. Now, starting my own business and really having to engage the public is very different because so much of my job now relies upon interacting with non-physicists and having to hire people and depend on others.
It’s a whole new world for me. There are skills I don’t have, so I have to hire people do the jobs. I’ve hired a business strategist, a social media consultant, a website programmer, a video producer, legal consultants. All I had to do before was work with a few physicists and write articles to be read by other physicists.
Q: In academia, you were surrounded by people who had years of experience and were natural role models. Have you had any people in your network who were able to give you guidance about how to start something like this?
Yes. Actually, when I moved to Paris, I just happened to make friends with several entrepreneurs independently. It was actually – well, I can’t say it was coincidence, because clearly there was something that drew me to these people – but I had about four friends that were all starting their own businesses. I really was inspired by this. In fact, my brother-in-law works for Apple, and for my birthday a year ago, he gave me the Steve Jobs biography, the Isaacson one. I read it, and while reading it, I could totally see myself launching one of these tech startups in Silicon Valley, and being a part of this, in sort of an alternate life. It really was very exciting. It was the same sort of excitement that I felt when I started doing physics and working on Einstein’s equations and feeling like I was making a change in the world.
So, I had these entrepreneur friends and I guess there were a few times I daydreamed about maybe starting my own enterprise, but what would I do? I’m just a researcher. What business would I start? And so it actually worked out perfectly when I realized there was this problem with support in our community, that I could actually start a business to solve it.
It was amazing how many things came together. In hindsight, it seems obvious that I should have been doing this, but, of course, I had planned to do research my entire life. It was a bit of a jump to actually make this leap.
"And so it actually worked out perfectly when I realized there was this problem with support in our community, that I could actually start a business to solve it."
When you’re a student or a post-doc, you get to spend almost all your time just doing physics. It’s like a child getting to play with toys all day. Then you grow up and you start to realize that money comes from somewhere, and you spend more of your time writing grant proposals and applying for jobs and interviewing people to work for you. And yes, that’s a necessary part of life, but it was very frustrating because so much of my time was spent writing grant proposals, which are read by government committees. It takes so much time to do this because we write these long grant proposals, which are read by government committees, so it takes a month to write them, six months to evaluate them, and there’s an incredibly small chance that you’ll actually be successful. The evaluation scores are so trivial, and it’s not like it really is the best 10% of proposals being funded. A fourth of the proposals should be funded, it’s just very trivial differences. It’s really discouraging for researchers to spend this much of their time unsuccessfully applying for funding.
I was noticing that a lot of my friends had left the community because they couldn’t find jobs, or were very discouraged. I remember a friend of mine, in London, had spent a whole week doing nothing but write a grant proposal for £10,000. There’s so much work he could have done in that week, for such a minuscule amount of money. It’s not so surprising that people in our field go into the financial sector and earn 100 times the money much more easily. I think there are a lot of people who really want to stay in our field but aren’t able to. The older I got, the more I realized this really was a big problem. I want to be clear: government funding is necessary, but I think it makes researchers very helpless because there’s nothing else that they can do. It’s researchers fighting each other for a finite amount of resources. There’s no way to bring in new sources of funding.
I find the experience of writing proposals for funding to be an excellent planning process. Taking the time to figure out what I want to do over the next few years, and then writing a proposal knowing my peers are going to be looking at it brings an extra rigor to the process, a kind of reality to it. That week that you friend spent for a £10,000 grant is discouraging, but I never feel like a week spent on a proposal that doesn’t get funded is wasted. Usually at the end of the week, I feel excited and ready to start on the proposed work. I see a lot of value in the process of going through a healthy, peer-reviewed funding source. However, I think that you’re exactly right in that the job of a review panel is so hard because there’s so much high quality work that can’t be supported.
These types of peer-reviewed committees are necessary, but so much of our time is being spent doing this. So my work gives people another option.
So how are things going so far?
Things have gone incredibly well. Obviously there have been a few bumps, since I’ve never had to start a business before. There’s a lot to learn. But overall it's been great. We have five clients already set up, and there’s a few more that seem likely.
Let me just say that I really admire your courage to listen to yourself when you felt something was missing.
I moved to New York and I’m living off savings right now, to start my own business. You might know, this has been a very different lifestyle. One similarity that it has with research is that they’re both about solving problems. Of course, a researcher has very theoretical and technical problems, and here they’re very practical problems. But I still run into little barriers every day about what I can and can’t do, but it has been fun trying to think of creative solutions.
Both also deal with a lot of uncertainty.
That’s right, because when you do theoretical work, the theory you’re working on could be completely wrong, or it could be correct but useless, and the work I’m doing now could just fail. A lot of them do. But, I still want to take a risk and try, because if it does work out, there’s a lot of good that could come from it.
So, when are you going to get your first $20 donation?
We should be live in a few weeks. I’m aiming for another two to three weeks. We’re finalizing some of the campaign pages. We have 95% of the material online already.
Well, that’s exciting. Can you tell us about the launch, how you’re imagining that?
We’re very active on social media. That’s one thing that is different from a lot of academic fundraising, which is done by each institution privately, and is more personal networking. We have Facebook, Twitter, LinkedIn, YouTube accounts, and we’ll have a blog. Obviously we’re going to try to publicize this as much as possible. I’ve gotten in touch with a lot of journalist and communicator friends to help me out. Everyone has been super supportive. Almost everyone I’ve spoken to about this has replied with some way that they would like to help. For example, everyone has offered to publicize it or put me in touch with someone. It really has been fantastic and has given me confidence that this is the right path. It now seems surprising that someone hasn’t done this before, because this has been such a problem for so long, and yet no one has taken the step to actively engage the public in supporting physics.
Have you thought about getting support from the NSF?
If they would like to help us, of course I’d be happy to talk to them. Right now I’m focusing on crowdfunding or donors who could make significant contributions. The government already does its part. As I mentioned in the promotional video, there have been huge budget cuts recently. Overall funding in high-energy theory has been cut 23%, for junior researchers its 46%, so it really has been horrible. I’m not going to pick on any particular political party, but all politicians are worried about getting reelected in the next term, and so high-energy physics probably isn’t on their priority list.
"It now seems surprising that someone hasn’t done this before, because this has been such a problem for so long, and yet no one has taken the step to actively engage the public in supporting physics."
Would you ever offer a workshop to people like me about how to effectively engage the public in physics?
That’s funny you mention that. I’ve wondered about this exact thing myself. In the six months that I’ve been getting this set up, we’ve developed advertisements for Twitter and Facebook and such, as well as a number of different slogans, if you will, and we’ve been trying them out with people. It’s been very interesting seeing which ones the public respond to. Of course, there are many science communicators who do have to think about such things, but I think I’m getting a unique perspective on this because it’s actually a business. I’m quantifying their success. 10% of people who see this ad click on it, whereas 12% who see this ad click on it. I think once we get going for a while, I will have an interesting perspective of how to engage the public. I will be happy to talk with people and share my experiences once we’ve been running for a while.
Is there anything else you want to add?
Only that I think the best thing about this is I’ve met so many people that I never would have met as a researcher, from all over the world. I was very fortunate. I just came from Cape Town, South Africa, where I spent the past six months. The office of the International Astronomical Union Office for Astronomy Development, IAU-OAD, is located there. They’ve been very supportive of Fiat Physica; in fact, the director there emailed about 200 project leaders, people who have some astronomy project that they wanted to develop, but couldn’t because of financial constraints, and suggested they work with me. I’ve had dozens of responses from astronomy outreach leaders all over the world, suggesting great projects that they want to set up. It’s been so interesting learning about all these people and their projects, and I never would have met these type of people just doing string theory research.
Finally, we invite all physicists and communicators to guest blog for our site on whatever topic they feel passionate about; we are really trying to establish an educational community.