- Out of all the guest video pitches
that I got this year, this one had the best title. You might recognise
Vanessa from BrainCraft. She was on Disconnected,
on this channel, earlier this year. She is a behavioural scientist. Her channel is about psychology
and self-improvement. So, this is not her usual area. But I wasn't going to turn down a pitch
about a radioactive beach in New York. Full disclosure, this was a
nightmare for her to film. It nearly didn't get made,
but the story is worth it. Vanessa, over to you. - So I'm in New York City,
deep in Brooklyn, and just over this sand dune is a beach that has recently been
deemed radioactive. We can't actually go onto the beach. It's been closed by the
National Park Service. It's appropriately called
"Glass Bottle Beach". It's full of glass bottles,
pieces of the city's history... ...and radium 226. So, to get over there, we're going
to have to get a little creative. So we're about 100 feet,
or 30.33 metres away from the Glass Bottle Beach,
the slightly radioactive beach. It's also as close as our boat
will physically allow us to get. While I'm trying to survive at sea, you may be wondering how a
beach can become radioactive. It all has to do with what
makes this beach so special, and that's rubbish, trash. There's lots of it,
because Glass Bottle Beach was an unofficial dump for decades.
But unlike the modern trash that lines New York City
streets, this is very old trash. I found a bottle in the
sand dunes from 1929. And when trash reaches a certain vintage,
it has some historical value. To an archaeologist, it's called "midden". And basically, it's a
collection of artefacts that tell us something
about a prior human society. Maybe to you, it looks like rubbish. And yes, a midden is domestic waste. But think of it as a resource for archaeologists to study
the diets and habits of past civilizations. When you think about what an artefact is,
trash plus time equals an artefact. That's the equation underlying
the entire field of archaeology! Some of these artefacts
are deep in the sand, and some get washed ashore. It's common to find a glass Coke bottle
from 1918 on the beach, and there's lots of stuff
there that can tell us about how people in Brooklyn lived
at the turn of the century. I think that's pretty cool, but it
might all be getting cleared out soon. Earlier this year, radioactive trash
was discovered at the beach; two broken Navy deck markers were found. Originally, they were used as
a low light source at night, because they contained radium 226, an isotope of radium at that
has a half-life of 1,600 years and decays into radon gas. The gas can enter your body
far more easily than radium itself, and both the radon gas and
gamma radiation on the beach now exceed ambient levels. The National Park Service closed the site, even though the danger of deck
markers has been questioned. And it's earmarked to be cleaned up. Meaning a lot of these really
old artifacts will be removed, even if they're perfectly harmless. So it raises this question of,
what is valuable to preserve? Because this isn't about radiation
as much as it's about urban archaeology. Let's imagine that in 200 years time,
people find all of our junk mail. Junk mail is probably something
that you would throw out. But if that comes up in the
future, if someone finds it, what would they be able to
tell about our human society from the crap that we
get in our letter box? Probably quite a lot that you
wouldn't find in official records. And we do preserve official
records, no questions asked. But what about artifacts? When all of our trash
teaches us that something about how civilizations live long ago, what responsibility do
we have to preserve it? I want you to think about that. Write down in the comments,
and I will see you there. - Check out Vanessa's channel,
it's called BrainCraft. Rather than exploring the world,
it's about exploring your own head. You could start with her
video on the growth mindset, or her video on lucid dreaming. And that's it for the guest videos
this time round! I am back next week. But until then, thank you
to all the guest presenters, and to you for watching. And I'll see you on the internet.
