This shiny metal is constantly in a liquid state.
This is mercury.
We normally see this metal in tiny quantities.
But what would happen
if we took thousands of liters of it
and filled a pool entirely with liquid mercury?
And then, what if you jumped into it?
Mercury is more than 13 times denser than water,
and substantially heavier.
It's also much thicker,
with greater surface tension than water as well.
So what would it feel like
if you jumped into a pool of this liquid metal?
Before we fill up our pool with liquid mercury,
we're going to need to find a lot of it.
Mercury is a rare metal found in the Earth's crust.
And due to it being so rare,
it's also quite expensive.
Filling an entire pool full of liquid mercury
would cost hundreds of thousands,
if not millions of dollars.
Once you've acquired all your liquid mercury,
you could now fill up your pool.
But due to liquid mercury being so much heavier than water,
you'd need to make sure that your pool is reinforced
to handle such a heavy weight.
OK, that was very time consuming
and expensive,
but we finally have our pool full of liquid mercury.
And now, it's time to jump in.
And as soon as you jumped in,
you'd be met with a thud
rather than a satisfying splash.
Due to the density of the liquid mercury,
you wouldn't sink down into the pool.
Instead, your feet would be submerged,
and that's about it.
If you were to dive headfirst into the pool
from a 3 m (10 ft) ladder,
then you'd probably get knocked out
from the impact of hitting the liquid mercury.
But just because you don't get injured from the jump itself
that doesn't mean you'd be safe.
Assuming you jumped into the pool with standard swim attire,
you wouldn't be wearing any shoes.
This means, at first,
your feet would be making direct contact
with the liquid mercury.
This would cause severe burns and irritation.
And this would only worsen,
as you'd most likely lose balance from just standing on your feet.
It would be like standing on watery Jell-O
and would be incredibly difficult to balance on.
So you'd most likely fall on your back or stomach.
You still wouldn't sink in,
but now, your whole body would be covered with the liquid mercury.
And the longer it stays on your skin,
the worse it would get.
Prolonged exposure to liquid mercury
would lead to it getting absorbed by your skin.
And once that happens,
the mercury would make its way to your organs,
including your brain.
This is where mercury poisoning would set in.
And if you think you could avoid this by wearing a wet suit,
and keep mercury from touching your skin at all,
think again.
That's because just inhaling
the liquid mercury fumes would poison you.
Sometimes even faster than just touching it.
The longer you stay in the pool,
the worse it would get.
You would start with a headache and feel woozy.
At this point, you should probably get out of the pool.
But even if you managed to survive this long,
this much exposure to liquid mercury
would stay with you for a long time,
if not forever.
Over time, the symptoms of mercury poisoning
would include speech difficulties,
lack of coordination, and even vision loss.
And if you didn't manage to get out of the pool,
you'd pass out and die from metal's fumes.
OK, so jumping into a pool full of liquid mercury is a terrible idea.
But let me tell you,
it wouldn't be the worst liquid to swim in.
Have you ever heard of Medusa?
The snake-haired Greek monster
who turns people to stone with a single glance?
Well, she may just be a myth,
but there is an area so deadly
that it could actually turn you to stone.
The infamous Lake Natron.
Before we take the plunge,
we'd better look at what Lake Natron is made of.
Much like the Dead Sea,
this lake in Tanzania
doesn't run off into any oceans or rivers.
This allows it to soak up all that salty desert rain.
Mmm, soupy.
Yet what makes it especially lethal,
is its close proximity to the active volcano,
The volcano spews a rare kind of lava
rich in sodium
and potassium carbonate, called
Releasing into the water,
this mix of sodium carbonate
and sodium bicarbonate
were key ingredients once used
in Egyptian mummification,
creating the perfect preservative in lake form.
The whole chemical composition
is extremely alkaline,
with pH levels of 10.5
close to that of ammonia.
This gives the lake its rosy hue.
Any birds who happen to take a dive
and don't make it out
become calcified in a hardened,
stonelike husk.
Talk about killing two birds with one stone.
In 2013, wildlife photographer Nick Brandt
was one of the first
to document this phenomenon.
He discovered several stone birds
and other unlucky animals
in the dry season when the water had receded.
He theorized that,
since the lake is so mirror-like and reflective,
the birds must have flown right into it.
As if it was a big glass door.
But despite so many birds dying in Lake Natron,
there is a particular species flourishing.
Turns out, the lake's toxic waters
provide a safe haven from predators,
making it perfect flamingo flocking grounds.
So if flamingoes can handle it, couldn't we?
Well, it's not that simple unfortunately.
Flamingoes thrive in salty lakes
because of their tough skin and scaly legs
which prevent burns.
They can drink the freshwater
from nearby springs
or geysers at the edges of the lake,
and if they're desperate enough,
they can even filter saltwater
with special glands in their nasal cavities.
And to top it all off,
their strong stomachs
allow them to feed on the toxic algae
found throughout the lake.
This makes Lake Natron the perfect spot
to raise and protect their young.
So, let's say we tried to live like a flamingo
and decided to take a dip?
Depending on the time of year,
the water can be up 60 °C (140 °F),
which is hot enough
to cause third-degree burns
in five seconds or less.
Also, I wouldn't plan on
doing any fancy dives or cannonballs,
as its shallowness
is also chock full of sharp, salty structures.
You wouldn't be turned to stone instantly,
but if you happened to drown
and stay submerged,
your entire body would harden
and be preserved.
If people found you hundreds of years later,
you might still have your hair and organs intact.
Yeah, looking spiffy after all those years.
Like mummification,
Natron's super high alkalinity
stops the decomposition process.
Thankfully, this means you'd be safe
from vultures or any other hungry scavengers
looking for a snack.
If you waded into the lake at a time
when the water temperature was lower,
it could feel more like a hot tub.
But your eyes or any open wounds
would sting like crazy because of all the salt.
I'd strap on some goggles if I were you.
In 2007, another bird flew straight into
this chemical cocktail.
A group of wildlife videographers
plunged into Lake Natron's toxicity
when their helicopter crashed.
The pilot suffered a broken leg,
and another passenger had a broken hip.
Incredibly, one of the passengers
managed to struggle to shore
and alerted some of
the Masai tribespeople nearby.
They quickly built stretchers
and carried the injured to land
in the nick of time.
Even though you could survive
Lake Natron's waters,
I'd stick to a swimming pool if I were you.
You could try a swimming pool of something more exotic.
Like your stomach acid.
It's as strong as battery acid and it can melt steel.
Your stomach acid lives inside of you
and helps digest your food.
That's right.
Stomach acid is compared
to battery acid in terms of the damage it can do.
It can range from a 1 to 3 on the pH scale,
meaning it's extremely acidic.
That's because stomach acid's main component
is hydrochloric acid,
which is a highly corrosive substance.
The reason it can live inside us
is due to a special mucous membrane that
lines our stomachs.
But what would happen
if we covered all our skin with it?
Now, before we jump into a pool full of stomach acid,
first thing we need to do is figure out,
how we're going to be able to fill up
an entire pool with stomach acid.
Let's assume we're swimming in an average 6x6 meter (19.6x19.6 ft) pool
that can hold about 55,000 liters (12,100 gallons) of liquid.
A stomach can produce at most,
1.5 liters (0.3 gallons) of stomach acid a day.
So to fill up an entire pool,
we'd need the stomachs of over 50,000 people.
Okay, we found 50,000 volunteers
who were able to help us fill up this pool.
Before you even jump into it,
you're going to notice the awful smell.
Whenever there's excess acid in your digestive tract,
it can cause your breath to stink.
So multiply that by 50,000,
and you'd get an idea of how
awful the pool would smell.
You'd be surrounded by horrible bad breath odor.
And that's even before you jump in.
As soon as you take the plunge,
you'll feel stinging in your eyes and your nostrils.
To get a sense of what this might feel like,
have you ever had lemon juice squirted in your eye?
It would be similar to that,
as lemon juice and stomach acid
have a similar pH level.
But if you remember to bring your goggles and nose plugs,
hopefully you'll be able to avoid this part.
What's much less avoidable is the stomach acid making contact with your skin.
When it does,
it will cause some mild irritation right away.
Luckily, the epidermis layer of your skin
should be able to protect you before it starts to hurt too badly.
If you jump into the pool and hop right back out,
even with your skin all covered in stomach acid,
you'd be relatively okay,
apart from some mild irritation.
As long as you wash the acid off with soap and water and towel off,
you'll be totally fine.
But what if you stayed in the stomach acid
for much longer?
If you didn't get out right away,
the acid would slowly eat your skin.
This would eventually leave you covered in second and third-degree burns.
If you didn't manage to cover your eyes during the swim,
you'd slowly lose your vision and end up blind.
And your nose would dissolve from the inside if the acid touched it long enough.
Oh, and if you accidentally swallow some of it,
you'll inevitably vomit it back up,
Ugh, what you'd have for lunch?
Given the dangers here it's probably best you don't try it.
You'd be best to leave stomach acid where it belongs,
and that's inside of us, digesting our food.
But what if we went inside a stomach?
More specifically, a whale's stomach?
Well, that's a story for another WHAT IF.