Good morning John. In the year 2000, Juan and Pedro Sanchez,
two brothers in Mexico were drilling down in a mine, a lead and silver mine.
It was hot down there, like 130 degrees Fahrenheit. It was, I imagine,
unpleasant and dangerous work. And mines are always contending with a lot
of different hazards, one of them though is water, because mines are underground
and water goes down. People and equipment both work best when they are
not submerged in 130 degree water, so mines almost always have huge
pumps that remove a tremendous amount of water from the ground so that people
and machines can work down there. So in this mine in Mexico, something
magnificent had been uncovered by those pumps. With that water
taken out, those brothers drilled down into a giant cave full of some
of the largest crystals ever discovered on Earth. Now an important thing to note,
you can not go visit the crystals. One, because the mine has since
stopped pumping the water out and so that cavern is now full of water again.
But maybe more importantly, the scientists who did get a chance to go
down into this cave, they had to wear some very special suits and those suits
were designed to do two things. One, keep them cool. Because not
only is it 130 degree Fahrenheit, that’s 55 Celsius, it was also extremely
humid because there’s a lot of water down there and all that water is evaporating
into the very hot air, so it was like 90-99% humidity in there which meant
that the water that you sweat can’t evaporate from your skin into the air.
There’s no room left in the air for more water so you have no system for cooling
yourself off and you would overheat and die. And more terrifyingly, they
also had to wear basically scuba equipment. They had to breathe air that they
carried around with them. But why? Because the air down there isn’t poisonous.
There’s not like some weird alien spores that are going to infect their lungs. It turns
out that 130 degree air can hold a lot of water right? So 100% humidity with 130
degree air, that’s a lot of water in the air. And when you bring the temperature
of air down, it can hold less water. So that water condenses out. That’s why lots of
water vapor going up into the atmosphere condenses into clouds when it reaches higher,
colder areas of the atmosphere. Yes, that's where clouds come from.
Also why a glass of cold iced tea has water condensing on the side of it,
because the air hits the side of that glass, cools down,
and water falls out. But when it’s 130 degrees, and 100% percent humidity
outside, you know what’s cooler than the air? The inside of your lungs.
So if you didn’t have a tank of air on your back, every breath you take in this cave would
condense a little bit more water in your lungs. A little more, a little more, until you
drown. Now this did not happen to anyone, they knew that it was a thing so they
were able to plan around it, but still. That’s wild. This is a really, really, really
cool planet. But in a sense, we kind of never should have seen that cave. And now
that the mine is no longer pumping the water our we can’t see it anymore it’s just
down there and we had this very narrow slice of like 5 years where we could examine
and study the giant crystals. We only got to see those crystals because of a truly
bizarre series of coincidences. This reminds me of how in Rome they’ve spent 40 years
trying to build a single Subway line but every time they dig they find some other
truly irreplaceable, remarkable archeological site. There’s just so much
that remains hidden from us. I told Katherine about these crystal caves
and she exclaimed on our walk home, the Earth is an alien planet! Which is
such a good line because of course there’s nothing less alien than the planet
that we evolved to exist on, that we as a species have barely ever left, that sustains
us everyday. But also, it is right? Even after all this inquiry it remains full of the
unknown. And it’s so inhospitable to us everywhere except the very narrow slice
just at the surface and yet as we continue to prove over and over again,
these unknowns are knowable. And I know this doesn’t make any philosophical
sense, but making those unknowns known, whether they are about avocados
and megafauna or giant crystal caves, it just seems like a very good use of time.
John, I’ll see you on Tuesday.