"I want to go back to about the late 1920s and 1930s when a new type of was invented, called the . These are still in operation today, but the original ones... This is a patent from... and this is 2 Ds as we call them... electrical cavities which would sit inside a whopping great ... [W]e start in the center with some particles, and they always have to be charged particles. So either electrons, s... s, charged atoms. Things like that, and we give them a bit of a kick, because there is a voltage between these two [Ds] halves, and each time the particle moves between those two halves they get a little bit of a kick, a little bit of energy. Now because they're sitting in a whopping great magnetic field, the effect... that has on a charged particle is to actually bend it around a corner. So it bends around a corner and it comes back again crossing this gap, gaining a little bit more energy and... as it continues to gain energy it spirals out... So the limit in the energy in this machine is mostly how big you can build your magnet, and how much iron you're willing to afford. Now this really was the original type of... high energy particle accelerator, and this is a photograph of Ernest Lawrence and his student Milton Stanley Livingston, who I should say, actually built the thing... [T]his machine got up to about 1 million s."