Belinda Smith

speaker

2,440 appearances 25 recordings 4 series first heard Apr 2026 last heard 5d ago

Belinda Smith’s voice in public audio — every appearance, attributed to the second.

Trend

recordings per month · last 12 months

Recordings per month over the last 12 months — 25 in all, peaking in Jul 2026 with 6.

Appearances

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The Science Show · Looking inside cells, and how seals hear so well underwater · 31 Jul 2026 podcast

The walls of the lab are coated with a type of spray on concrete, which is then painted with a special low-radioactivity paint.

The lab isn't just clean, it's also got just about the lowest levels of radioactivity anywhere in the world.

Down here, there are two main sources of radiation that scientists have to worry about.

As Ray Bunker explains, the first issue is the particles that bombard the Earth from deep space and from our own atmosphere.

The main reason for going underground

is to shield our experiments from cosmic ray muons, which are created in the upper atmosphere by primarily protons that come from outer space and hit the atmosphere.

Muons are very penetrating.

The only effective way we have to shield from them is to go deep underground and use this two kilometers of Earth as shielding against the cosmic ray muons.

So having all of this rock above our heads helps to minimize the number of pesky muons that get through.

But the rocks themselves are also slightly radioactive, which means the dirt that we trampled through as we walked through the drift is also a little bit radioactive.

And that's why we have to change clothes once again.

The mining gear comes off, and everyone has to take a shower so that we don't bring bits of radioactive dirt with us as we enter the lab.

They're especially adamant that everyone washes their hair.

Apparently your hair can be a real hornet's nest of radioactive dirt.

You're the object that's emitting too much radiation, and the concern is that you will contaminate the lab.

Now that we've scrubbed ourselves down and put on clean lab clothes, we can tour the laboratory.

Try to picture a rabbit warren scaled up to the size of a small village.

There are cavern-like chambers filled with lab equipment of every description, control rooms with banks of computer terminals, and dozens of scientists going about their work.

Our first stop is an experiment designed to snare particles of dark matter.

So now we're in the corner of the ladder labs where the super CDMS dark matter experiment is located.

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