♪ Soft, mellow music ♪
- [Dianna] We are here at a warehouse
in Porterville, California.
That is David Blaine hanging from a cluster
of very colorful balloons.
David Blaine. Yes. That David Blaine.
- [David] The cards will just jump out of the deck.
Oh, wait, and it landed under your watch.
- (man laughing)
- [Dianna] He's up to something new and unusual.
- [David] Just to go back on everything.
This idea has been a dream forever since I was, well,
I think it's kind of universal,
but in the last year I took it very seriously.
- [Dianna] David invited me behind the scenes
to witness the extensive testing for his newest stunt.
He's attempting to go as high as possible in the atmosphere
carried by a cluster of colorful weather balloons.
- [David] So I had to get a hot air balloon pilot license.
I got my gas restriction lifted and then I had to become
very confident and comfortable in the air.
So I had to get hundreds of skydives in really fast,
which has all been an incredible journey.
- [Dianna] Do you feel like you're experienced now?
You've had enough jumps to be...
- [David] No, of course not.
- [Dianna] When I first spoke to David,
his goal was to go up in the atmosphere as high as possible,
and then skydive back down.
So let's talk about altitude.
His realistic goal is 15 to 20,000 feet in the atmosphere,
which is the height at which skydiving planes start
to require supplemental oxygen.
But a stretch goal was the dream of 25,000 feet.
- [David] But I've also been doing altitudes of up to
almost 25,000 feet. And I've been testing it without oxygen,
which according to everybody, that's the death zone.
When you go to 26,000 and above, you can't survive there,
but I don't believe that, and the reason I don't believe
that is because Sherpas are up at the top
of Mount Everest with nothing.
- [Dianna] And that's.
- [David] And they're always okay.
- [Dianna] That's 29,000 feet.
- [David] Exactly.
- [Dianna] Which is 3000 feet above the beginning.
- [David] The death zone. Right.
- [Dianna] Of the death zone.
- [Dianna] The death zone seems like a good place
to start our investigation.
The quote "Death Zone" is 26,000 feet above sea level,
and is widely considered the level above which
there isn't enough oxygen for humans to survive.
For reference, the top of Mount Everest is
3000 feet above that.
While it's impressive,
even if David makes it to 15,000 feet
and skydives back down, which is the ultimate plan.
- What it looks like they just tested was
David putting on his parachute,
because he won't be wearing it as he's ascending,
which is crazy.
- I was curious what this stunt will do to the human body,
and what he will need to do to survive.
And then beyond that, I wondered what would happen
if someone took this cluster of balloons above
the death zone and whether that's even possible
in a cluster of balloons.
So let's take a look.
[Luke Aikins]It's interesting because as the balloons
get higher, the helium expands,
we get less and less pressure.
If Burt's calculations are right,
the balloon's going to grow by two feet.
So set of eight foot, it should be 10 feet.
- [Dianna] I mean, that's something I was really
curious about because I know as you go up gas expands.
- [Luke Aikins] Yep.
- [Dianna] Gas expands as you go up in the atmosphere
because the pressure drops.
We know this well now,
but one of the first documented cases investigating this was
two crazy Victorian explorers in 1862,
who took a hot air balloon up to 37,000 feet.
One of them passed out and they barely made it back alive.
But as they were ascending,
they were dropping birds out of the plane.
And then they threw a third bird out at between four and
five miles, which is 20 to 25,000 feet.
And quote "it fell downwards as a stone".
So at lower pressure air becomes thinner.
- [Dianna] I want to show you an experiment to talk about
the fact that the air gets thinner.
- [David] Okay?
- [Dianna] Okay.
- [David] Amazing.
- [Dianna] Yeah, so they expand...
- [David] That is so cool!
- [Dianna] So much because the pressure is no longer
pushing the balloons back in.
- So, as you climb up the atmosphere,
say you reach 9,000 feet or 2,700 meters,
you might start to experience a persistent mystery cough.
At 9,000 feet, the pressure is just 27% lower
than sea level, but you might already experience
swelling of the lungs due to blood vessels constricting
in a condition called high altitude pulmonary edema,
or HAPE, which can cause the unexplained coughing.
And as for the balloons going up, what happens to them?
- [Luke Aikins] So today's test is interesting.
We've flown this up to eight or 9,000 feet and it looks
identical at eight or 9,000 feet.
- [Dianna] This is a sand bag meant
to match David's exact weight,
so they're using this as a stand-in for his weight for now.
- You know those like candies, Nerds?
Looks like a little cluster of Nerds got stuck together.
- [Luke Aikins] But today we're going to get
up into the twenties, right?
And that's where we should see a
significant difference in balloon size.
- One of the biggest worries with a drop in pressure though,
is the bends.
There are gases dissolved in your blood and Henry's law
tells us that as the pressure on a liquid significantly
drops, it can hold less dissolved gas,
so the gases start to bubble out.
This is known as decompression sickness,
and scuba divers are very aware of it.
The first documented case of decompression sickness though,
was with a coal miner in 1841,
who described muscle cramps and pain.
Mine shafts were pressurized to keep water out,
which meant that more gas could dissolve in your blood
while you're working there.
So it's quite unlikely David will have to worry
about the bends at the heights he'll reach.
So here's another question.
Why don't we experience decompression sickness on planes
that go up to 38,000 feet?
Well, cabins are pressurized to about 8,000 feet,
and it's not just for comfort.
As you continue to ascend, say you get to 15,000 feet,
your heart will start to beat faster and faster to get more
oxygen to your brain because there's less oxygen
in that thinner air.
You start to feel tired like you can't catch your breath
because your body is responding to getting less oxygen
with each breath.
To combat the lack of oxygen,
David will be turning to his breathing techniques.
- [David] I started using my breathing technique
where I was basically slow breathing and purging slightly.
And...
- [Dianna] What does - what does purging mean?
- [David] Purging is
(forced exhale)
similar to hyperventilating where you're basically
- [Dianna] Ah!
- [David] Getting rid of the CO2
to make more room for oxygen.
- [Dianna] Gotcha. Now does it make you lightheaded?
- [David] I've done probably over a thousand breath holds
at 10 minutes a piece.
- [Dianna] I should've, I should've clarified what I meant.
Does it make you lightheaded,
I mean, like, the average human?
- [David] I'm so used to it. Yeah, it's not good,
and nobody should do that,
- [Dianna] Right, right, right.
- [David] But I'm pretty used to it. It's just a technique
- [Dianna] It's your technique.
- [David] And what you're doing is you're building
a resistance to CO2 buildup in the bloodstream.
- [Dianna] I see. I see.
- [David] It's really about a tolerance level.
- [Dianna] Gotcha.
- The oxygen level in your blood
is very important for your brain.
At 15,000 feet, some people experience
impaired cognitive function, which means that
if you have trouble remembering someone's name
when you meet them now, it would be impossible
with this low brain oxygen condition called hypoxia.
Speed dating would be out of the question
because you lose attentiveness.
Although, poor judgment is also a factor,
so maybe you would just pick the first candidate.
So, David will need all of his cognitive function because
he'll be putting his parachute on in the air.
- [Dianna] Reaching.
- [David] So I started the purging technique
at about 15,000 feet.
- [Dianna] Mm-hmm.
- [David] My pulse oximeter jumped up to 99% right away,
and Luke's was slowly dropping,
as we got to about 18-19,000, his was dropping
to about 80 and mine was still at 99,
so he said, "that's not real".
And I said, "okay, let's switch".
So I switched oximeters for his.
- [Dianna] A little control.
- [David] And mine was immediately up to 99,
and his was right back down to 70 something.
- [Dianna] With lower pressure and thinner atmosphere
often comes lower temperatures.
That's not always the case because the atmosphere protects
us from powerful solar radiation.
But generally when gases expand, they get colder.
We saw this happen when David's crew
blew up the helium balloons.
- They're filling up a bunch of balloons right now,
which means I get to use my thermal camera to watch
the balloons fill up and see how cold they get.
So will David have to worry about the temperature
as he ascends?
- [David] So you lose about three and a half,
a little less, degree, about three and a half degrees
Fahrenheit every thousand feet.
So if we go up to 20,000 feet, for example,
that would be minus 66.
- [Dianna] Right, right.
- [David] So we'd be at 33, which is...
- [Dianna] Yeah.
- [David] That's just normal freezing.
So that's not a concern.
- [Dianna] Okay.
- [David] Now
- [Dianna] And you're not going to be there for very long.
- [David] No, but the way I had originally thought
about this is that if I was going to do it somewhere else
in a different time of year, it would,
I was assuming it would go down to minus 20.
- [Dianna] Yeah, yeah.
- [David] So this is a blessing.
- [Dianna] If David continued up, he would have to worry
about temperatures though.
At 40,000 feet, which is about the height
of a commercial airliner, the temperature drops
to about minus 56 Celsius, which would give you frostbite
within five minutes with any amount of wind.
Although the temperature climbs back up to a balmy minus two
at 160,000 feet, but at that point,
the balloons would have definitely popped.
Plus there's no chance of breathing up there.
You'd have to take a thousand breaths to get as much oxygen
as you would from one sea level breath.
Interestingly, if you went up to 2 million feet,
the atmosphere is pretty much all helium anyways,
although there's effectively no atmosphere at that height.
I think it's safe to say though, that no one is getting
up to 2 million feet in a cluster of balloons.
Besides the discussion of what happens to your body,
there were so many interesting engineering challenges
that went into this stunt.
I'm going to really quickly list my favorites.
In addition to lifting David,
there's a really heavy payload that needs
to be brought up by the balloons,
because they need to have cameras live streaming
the whole thing, and each eight foot balloon
only lifts about 15 pounds.
The little balloons, the four foot ones,
only lift about two pounds.
So you need a lot of balloons.
Plus since the whole event will be live streamed,
you need these big antennas to send a strong enough
signal back down to Earth.
So they decided to use circular antennas
to keep it more compact.
Also quite impressive was the fact that the whole crew was
preparing this in like a hundred degree weather.
It was so hot there.
Oh, also the balloons can't ascend too fast
because otherwise they'll start to knock together and pop.
So to keep the rates slow, they need to pop balloons,
but David's not controlling that.
- [Luke Aikins] It's the oldest form of aviation,
and I thought it was really simple.
And I'm finding to go up is very simple,
but to do a controlled up, it, it requires a lot more.
I've become a balloon expert.
- [Dianna] There's basically a mission control
down on the ground
and all these strings with little explosives attached
to every single balloon,
so that mission control can pop them remotely.
I thought that was a pretty creative idea.
Anyways, I wish David the best of luck,
At this point, he might've actually already jumped
by the time this video comes out.
It was so cool to get to watch
the whole preparation process.
I hope you learned something today
because I definitely learned a lot making this video.
Happy physics-ing!