Hey, Professor! Star in a Bottle

Construction will shortly begin on the long-anticipated International Thermonuclear Experimental Reactor—a machine that, if it works, promises to solve most of the world’s energy problems for the next 30 million years. Howard M. Georgi ’68, a Harvard physics professor, sat down for a brief chat about how and whether ITER will actually work as well as its possible economic and political implications.

1. Fifteen Minutes: Could you explain in layperson’s terms what the International Thermonuclear Experimental Reactor is and what it does?

Howard M. Georgi: The quick summary is simple–it makes energy in a way very similar to the way the sun makes energy, by fusing hydrogen into helium....The problem with fusion is that to get [nuclei] to come together you have to get [charged hydrogen nuclei] going very fast and get them to run into one another in order to let this reaction happen....The strategy of most of the games at the moment is to fuse rare isotopes of hydrogen (deuterium and tritium) into helium, which means there’s an extra neutron left over. And that’s advantageous for a number of reasons, but in particular the neutron can then get out and carry the energy from where the fusion is going on out into the surrounding area....It’s this elegant balancing act; there’s a whole bunch of delicate balancing acts with this process.

2. FM: So here’s the big question: do you think it will actually work?

HMG: I actually have no idea. I’ll be surprised if I find out in my lifetime because I think it’s quite a long-term project....I think that [the goal of beginning experiments in 2020] is great, and I await the results with interest, but it’s such a complicated project. I’m a theorist and just a tiny, tiny piece of this is the theory. By far the bulk of it is the engineering and real civil construction and the politics, which is probably the biggest part of it. Somehow we managed to get that done with the [Large Hadron Collider] and occasionally with huge telescopes, and those are motivated differently because those are purely for basic research.... This is much more applied, but certainly the engineering is no easier.

3. FM: In the event it actually works, the impact would be absolutely phenomenal though, right?

HMG: Oh absolutely.... It’s great because they’re just starting to build it and [in] starting to test it they will learn a lot. We will learn a lot about, for example, the properties of plasmas in very high magnetic fields, and that’s interesting for lots of good scientific reasons. And they will learn a tremendous amount about how to engineer a project of that scale and that complexity. So all of that is terrific. Where it goes after that, I don’t know.