Vsauce! Kevin here.
One of the most dangerous situations you can find yourself in is toasting bread while taking
a bath. You’ve seen enough toaster-in-the-tub movie scenes to know that when the plugged-in
toaster falls in the water, it’s fatal.
WHY!? How powerful is a toaster?
Well, a taser blasts at about 50,000 volts, which sounds like a lot of power, but it’s
really about the current -- a taser causes “neuromuscular incapacitation” at 2 or
3 milliamps. Reliable lethality starts at about 100 milliamps. A toaster plunges into
your bubble bath with 5-10 whole amps. That’s bad. But... not nearly as bad as BOLTS OF
LIGHTNING. So why don’t all the fish die when a lightning strike blasts anywhere from
5,000 amps to 200,000 amps into the ocean?
And if the heat from a lightning bolt is so hot, why don’t fish just cook when the ocean
is struck? They should get shocked and boiled alive instantly.
FISH LIGHTNING OCEAN SOUP. WHAT IS LIGHTNING?
Lightning happens when particles in clouds collide and generate a charge, then that charge
has to go somewhere. Most of the time that’s within clouds, but a quarter of the time it
discharges to the surface. Not very often on the ocean, though -- the air above water
is just too cool. Too cool for school. Too cool to create the conditions for a thunderstorm.
Lightning is literally 10 times more common on land. But occasionally the fish are gonna
get BLASTED.
The thing is... they’re generally safe because of where they live and how electricity works.
Salt water is an excellent conductor, so when lightning slaps the ocean surface it engages
the skin effect, which means that the current is primarily spread across the surface of
the conductor it hits -- almost like a protective shell. It’s the same reason lightning striking
a car doesn’t just nuke a hole through the roof and explode the insides -- the current
travels on the outside surface of the metal car. But that means if you’re swimming in
lightning water, you’re going to get zapped to death because you’re right on the surface.
If you’re hanging out the window of your 1991 Ford Mustang GT and lightning hits it,
then you’re gonna feel that. But if you are a tuna 50 meters below the surface, you
probably don’t even know that lightning just hit.
You probably don’t even know WHAT LIGHTNING IS. YOU’RE A TUNA.
BUT! If you’re a fish glub-glubbing along three meters below the surface, things are
going to go very badly for you. The lightning is gonna penetrate enough to send current
into your water, and it’s going to be hot. Like 50,000 degrees Fahrenheit hot -- 5 times
hotter than the sun. You are not surviving this lightning, fish. I am sorry.
Let’s talk about MAKING SWORDS.
You’ve seen movies or video games where a blacksmith plunges a freshly-forged sword
into a water bath to cool it down. There’s steam and there’s a hiss, but that water
doesn’t just start boiling even though it’s injected with something about 2,000 degrees
Fahrenheit. Why? Because water does a really good job of sucking up and distributing heat
evenly, so all that lightning heat is gonna get spread out and be less lethal. Hi. At
this point during the recording the toaster is toasting off-screen and burning the bread
badly. Smoke is billowing out and filling the room. So this happened. Both the heat
and the current dissipate quickly. Oops. Oops, oops. I set off the smoke alarm in the house.
Excuse me!
Okay, I’m back. I opened up the windows and got the smoke out of here. Everything’s
fine. No need for the fire department. Okay? Let’s get back to talking about making swords.
So. Like I was saying. When the blacksmith dunks his freshly made sword in the water
it doesn’t start boiling because water does a really good job of sucking up and distributing
heat evenly, so all of that lightning heat is gonna get spread out and be less lethal.
Both the heat and the current dissipate quickly away from the strike. And all of this combined
is why people usually don’t die from getting hit by lightning.
About 25 people per year are struck by lightning in the US, and around 90% of them live. They
get physically blasted by the force of lightning, sometimes thrown up into the air, but the
current tends to go across the surface of their skin -- it’s called “flashover.”
Superficial blood vessels can actually respond to that electricity by making a weird pattern
called a Lichtenberg figure -- and yes, you are likely to get burned. But not too seriously,
because the heat only lasts for a few microseconds, and it’s just not long enough to deep fry
you. Internal organ damage you can’t see? Yeah, that’s possible, so don’t run around
naked during a thunderstorm. In case you were planning on that. Don’t.
So what’s the real problem when it comes to getting struck by lightning? And why don’t
you want to stand out on your rooftop waving a steel pipe over your head while lightning
is crashing down? Your heart.
Lightning is more than enough to disrupt the operation of your heart and shut it down.
Your heart is a muscle that runs on electric impulses, so even if 50 milliamps of current
reach your heart, that system is disrupted enough to cause arrhythmia -- and if it’s
more severe than just being irregular, you’ve got ventricular fibrillation -- your heart
is basically useless at pumping blood. And you need blood. Immediate CPR to the victim
of a lightning strike is usually a necessity to get their heart working again, or by using
a defibrillator that sends its own current into your heart to... de-fib the fibs. So
yeah, current causes the problem and then current solves the problem.
It turns out… There’s no one around to give fish CPR or the appropriate level of
electric defibrillation. If they’re swimming close to the surface within a short radius
of a lightning strike, it’s time for fish sticks. Zapped and cooked.
But here’s a question I have in my brain... How many fish is that? HERE’S HOW MANY APPROXIMATELY.
There are probably around 3.5 trillion fish in the Atlantic Ocean alone, and the Atlantic’s
volume is about 310 million cubic kilometers. That’s around 11,000 fish per section of
Atlantic that’s a kilometer in both directions and a kilometer deep. A handful of fish might
be in the wrong spot at the wrong time to suffer electrical and heat damage from lightning,
but it’s just… not a huge deal and it’s not deep frying the contents of the ocean.
So yeah, some fish might die when lightning strikes. The other gazillion are fine.
And as always -- perfect, thanks for watching.
Sobbing What’s wrong, Kevin?
My brain is smooth… Put wrinkles on your brain with the Vsauce
Curiosity Box I can feel the wrinkles already…
Ahhhhh!!!!