 In the field of seismic isolation is the one in which there's been the most direct amount of testing and research. To use a seismic isolator allows an engineer to take control of how a building will respond to an earthquake. In a conventional design approach, we try to make the building strong enough, and then we try to anticipate how that building will respond during a strong earthquake and try to have it not fall down. And there's a lot of unknowns in that and sometimes it's difficult to know exactly how a building will respond to an earthquake and which parts might be damaged and if it might fall down. When we put seismic isolators under a building, we transform how the building responds during an earthquake. So all of a sudden instead of shaking violently, the building will sway gently back and forth as if it were a pendulum. And that way, since it gives us a very predictable motion, we can engineer exactly how we want it to respond during an earthquake. So now it's not really a matter of sort of accepting what would happen, but it's a question of taking control of what will happen. And therefore we can dictate essentially any level of protection for a structure. If we have a very weak structure, we can put in bearings that will almost completely absorb all the earthquake shocks. And if we have a stronger structure, we can put in smaller bearings that will serve the same purpose. The way these pendulum bearings will help to protect the structure from an earthquake is, let's say at each point in a structure that we want to support the structure, we will put this sort of concave pole. And then we will support the weight of say each column in a building on a little ball that sits in that surface. And then when the ground moves during an earthquake, the ground will move sideways, and instead of taking the structure with it sideways, it's going to lift the structure. And it takes a lot of energy to lift the structure two or three inches. So in that way we've kind of absorbed the energy of the earthquake in lifting the structure rather than moving it sideways. And that slight lift as it occurs over and over again is the same motion that you would get say with a simple pendulum with a grandfather clock. So that period that it moves back and forth is a constant period that depends only on the curve of that surface. Probably there are in the order of 50 buildings in the world that are using these friction pendulum seismic isolators. And they're all special buildings in some way, buildings that we wanted to protect for some reason, either because they were very important buildings to the operations of emergency services or historic structures like the Pioneer Courthouse.