The inventor of the idea, and the chief donor to the Perimeter Institute, is Michael Lazaridis, who is co-chief executive of Research in Motion, the company that makes Blackberries. He and the board he created made it clear that what they wanted, structurally, was something like the Institute for Advanced Study, in Princeton. They set the mandate, they set the framework, but they are not involved in day-to-day issues of scientific direction and hiring. Mike is absolutely essential, but he's never come to us and said, "I think you have to hire this person" or "I think that that's not a good direction to go in." One thing they did very early was to create a committee of prominent scientists as advisors, to oversee what we do. They're there to see that we don't wander off in strange directions scientifically—to keep us honest.

We're now in a funky old building in Waterloo which used to be a restaurant; my office is next to the old bar. There's a wonderful atmosphere; people love it. Construction has started on a new building designed by two fantastic young architects from Montreal, Gilles Saucier and Andre Perrotte. At the beginning of the process, we traveled with them to Cambridge and London, where people have recently built buildings for physicists and mathematicians, and talked about what works, what doesn't work, and why. I believe that our building is going to be a better place to do theoretical physics than anything that exists now. We already are said by some to be the hot place in two fields—quantum gravity and quantum information theory. We opened in September 2001, which was a strange time to begin any endeavor, starting with three scientists on long term appointments; Robert Myers, Fotini Markopoulou, and myself—a string theorist and two people in quantum gravity. Very much present in our minds from the beginning was the idea that we were not going to favor one particular approach. We have good people in both camps, and we are creating an atmosphere where people in different camps will talk to each other. A lot of good science has happened so far. We hired two very good people in quantum theory: Lucien Hardy, from Oxford, who has done exciting work in foundations of quantum theory and quantum information theory; and Daniel Gottesman, a young star of quantum information theory. In 2002, we had ten postdocs, several visitors, lots of people coming and going. In June, the Canadian prime minister and the minister of industry visited and pledged more than $25 million to our support. The deputy provincial minister of Ontario also came and pledged at least $11 million. It was heartening to see that the leaders of at least one country understand that the support of pure science is essential for a modern democracy.

Science is a kind of open laboratory for a democracy. It's a way to experiment with the ideals of our democratic societies. For example, in science you must accept the fact that you live in a community that makes the ultimate judgment as to the worth of your work. But at the same time, everybody's judgment is his or her own. The ethics of the community require that you argue for what you believe and that you try as hard as you can to get results to test your hunches, but you have to be honest in reporting the results, whatever they are. You have the freedom and independence to do whatever you want, as long as in the end you accept the judgment of the community. Good science comes from the collision of contradictory ideas, from conflict, from people trying to do better than their teachers did, and I think here we have a model for what a democratic society is about. There's a great strength in our democratic way of life, and science is at the root of it.

Now I want to talk about the problem of quantum gravity and the two best developed approaches that have been proposed to solve it, which are called loop quantum gravity and string theory. This is a case in which different people have taken different approaches to solving a fundamental scientific problem, and there are interesting lessons to be learned from how these theories have developed since the early 1980s—lessons about space and time and also about how science works.

Quantum gravity is the name we give to the theory that unifies all of physics. The roots of it are in Einstein's general theory of relativity and in quantum theory. Einstein's general theory of relativity is a theory of space, time, and gravity; while quantum theory describes everything else that exists in the universe, including elementary particles, nuclei, atoms, and chemistry. These two theories were invented in the early twentieth century, and their ascension marked the overthrow of the previous theory, which was Newtonian mechanics. They are the primary legacies of twentieth-century physics. The problem of unifying them is the main open problem in physics left for us to solve in this century.

Nature is a unity. This pen is made of atoms and it falls in the earth's gravitational field. Hence there must be one framework, one law of nature of which these two theories are different aspects. It would be absurd if there were two irreconcilable laws of physics, one for one domain of the world and another for another domain. Even in 1915 Einstein was aware of the issue, and in his very first paper about gravitational waves, he mentions the paradox of how to fit relativity together with the quantum.

It's only since the middle 1980s that real progress began to be made on unifying relativity and quantum theory. The turning point was the invention of not one but two approaches: loop quantum gravity and string theory. Since then, we have been making steady progress on both of these approaches. In each case, we are able to do calculations that predict surprising new phenomena. Still, we are not done. Neither is yet in final form; there are still things to understand. But the really important news is that there is now a real chance of doing experiments that will test the new predictions of these theories.

This is important, because we're in the uncomfortable situation of having two well-developed candidates for the quantum theory of gravity. We need to reduce these to one theory. We can do this either by finding that one is wrong and the other right, or by finding that the two theories can themselves be unified. (Of course, the result of testing the theories could be that both of them are eliminated, but this would be progress, too.)

Until a few years ago, the situation was very different. We didn't know how to test the theories we were working so hard to construct. Indeed, for a whole scientific generation—that is, since the middle 1970s—fundamental physics has been in a crisis, because it has not been possible to subject our theoretical speculations to experimental test. This was because the new phenomena that our theories of quantum gravity predict occur at scales of energy many orders of magnitude greater than what can be created in the laboratory—even in the huge particle accelerators. The scale where quantum physics and gravity come together is called the Planck scale, and it is some fifteen orders of magnitude higher in energy than the largest accelerators now under construction.

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