So when we're thinking about radiation and radioactivity, it is worth keeping in mind that just the fact that something is radioactive does not means… - Suzie Sheehy

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.

In the days of Cockroft and Walton, when they were first developing particle accelerators they didn't know about the dangers of radiation, and so one of the ways that they counted the events... what was happening in their experiments, was... to sit... under the beam. The beam would come down, some nuclear reaction would happen, and... his fluorescent screen... would light up every time what they were looking for happened... [T]hey would sit there and count each time it lit up, sitting underneath the beam, being irradiated. ...[T]hese people lived relatively healthy lives, and Cockroft and Walton got a for work, which doesn't justify it, but there have been people who have stuck their heads in particle accelerators.

I'd just like to leave you with my advice in choosing your career... [F]ind something that makes you sit up and think, "This is really important" or "This is fascinating" or "This is what I'm passionate about" and it can be in any area... Something like space might get you, of climate change... you might really like astronomy, or you might be more passionate about world hunger, injustices in the world, the availability of water, energy, health, aging, anything like that. Think about it, and do something about it. That's all, really, you need to do, and make a career out of doing something about it. Because if you do something that you're passionate about, and you love... You're not even going to feel like you're going to work each day. ...You're just going to feel like you're getting up and you're doing what it is that you're passionate about...