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Why Don't Birds Get Electrocuted on Wires? | Science Podcast for Kids · The Curious Kidcast | Fun Facts and Curious Questions

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  Somewhere near you right now, there are birds sitting on
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  electric wires. Not just any wires, power lines.
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  Wires carrying enough electricity to power hundreds of
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  homes, light up entire streets, and probably cook a fairly large
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  Turkey in about four seconds. And those birds are just sitting
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  there, feet on the wire, eyes half closed, completely fine,
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  chilling like they're on a little feathery holiday.
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  So here's the question. Why don't they get electrocuted?
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  Why aren't they getting zapped, fried, or launched off the wire
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  like a tiny confused firework? Today, we're going to find out.
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  Curious kid cast? Here we go.
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  Questions poppin. Minds will blow.
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  Big ideas. They're taking flight.
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  Let's explore. Feel the line.
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  Welcome to The Curious Kid cast, the show where we take the
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  questions bouncing around inside your brain and actually answer
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  them properly with real science, terrible jokes, and absolutely
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  zero homework. I'm Charlie, and before we dive
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  in, I need to tell you about something brilliant that
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  happened after last week's episode.
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  You know how we talked about what happens if lightning
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  strikes a car? Well, a kid called Freddie from
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  Cape Town was listening, and after the episode, he looked out
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  of his window, saw some birds sitting on a power line, and
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  immediately sent us a question that genuinely made me stop
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  walking and stand in the middle of the kitchen thinking for
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  about 3 minutes. Freddie wanted to know, why
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  don't birds get electrocuted when they sit on wires?
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  Freddie, that is a spectacular question.
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  It's the kind of question that hides in plain sight.
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  Every single one of us has looked up at birds on wires
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  probably hundreds of times, maybe even waved at them like a
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  complete weirdo, and not once thought, hold on, shouldn't
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  those little creatures be absolutely fried right now?
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  And yet here we are, and nobody has ever seen a Sparrow explode.
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  Which honestly, is a bit of a miracle when you think about it.
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  So today we're going to answer it.
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  And by the end of this episode, you'll understand something
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  about electricity that most adults couldn't explain even if
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  you gave them a week. A large white board and a very
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  encouraging sticker chart. Let's start with the most
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  important thing about electricity, because people get
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  this wrong all the time. Electricity is not like a
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  monster that zaps everything it touches.
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  It's more like a very lazy river.
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  It only flows when it's got a complete path from one place to
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  another. Scientists call this a circuit.
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  Without a complete circuit, electricity just sits there
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  doing absolutely nothing. Like that one person in a group
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  project who never pulls their weight.
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  It needs a reason to move, and if it hasn't got one, it won't
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  bother. Now here's where the bird comes
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  in. When a bird lands on a single
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  power line, both of its feet are on the same wire at nearly the
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  same point. Because of that, there's almost
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  no difference in electrical pressure, which scientists call
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  voltage, between 1 foot and the other.
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  And if there's no difference in voltage across the bird's tiny
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  little body, the electricity has no good reason to go through it.
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  The current stays in the wire because the wire is a much, much
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  better path. The bird is basically invisible
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  to the electricity. It's just being completely
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  ignored, like a soggy crisp at a birthday party.
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  Here's a brilliant way to picture it.
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  Imagine a really fast water slide with loads of water
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  rushing through it at top speed. Now imagine someone puts a
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  slightly damp sock next to the slide and says hey water, what
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  about going through this instead?
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  Is the water going to stop and go through the sock?
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  No, absolutely not. The sock is a terrible route.
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  The birds body is that sock, the power line is the water slide
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  and the electricity just keeps zooming along completely
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  unbothered, not even glancing at the bird.
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  Now, I can already hear some of you thinking, but Charlie, if
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  the wires full of electricity, surely the bird gets at least a
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  tiny bit zapped. And honestly, fairpoint, the
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  truth is a very, very tiny amount of current might
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  technically pass through the bird.
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  So small it's measured in something called micro amps.
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  To give you an idea of how tiny that is.
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  It's like comparing a single raindrop to an Olympic swimming
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  pool. The bird doesn't feel it.
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  It's nothing. It probably feels more
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  discomfort from the wind than from that, but here's the twist.
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  This is the bit that makes the whole thing genuinely
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  interesting. Birds actually can be
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  electrocuted on power lines, it just usually doesn't happen.
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  And here's exactly why. It only becomes dangerous when a
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  bird touches 2 wires at the same time, or when it touches a wire
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  and something connected to the ground, like the metal pole
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  holding the wires up. When that happens, the bird's
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  body suddenly becomes a bridge between two points with
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  different voltages that gives the electricity a brand new path
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  to travel. And electricity, being the
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  opportunist it is, will absolutely take it straight
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  through the bird. Not great for the bird.
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  This is why small birds are generally safer than big ones.
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  A tiny Sparrow sitting neatly with both feet on one wire is
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  almost always fine, but a large bird like a hawk or an eagle
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  with a massive wingspan might accidentally clip a second wire
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  or the top of a pole when it's landing or taking off.
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  At that point, things go very wrong very quickly.
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  Power companies actually spend serious money designing
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  equipment to protect large birds of prey from exactly this
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  problem. So next time you see a hawk
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  flying near some wires, give it a little nod of respect, because
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  it's navigating A genuinely tricky obstacle course.
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  Now you're probably wondering, OK, but why do humans get
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  electrocuted if birds don't? Here's the key difference.
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  Humans are almost always touching the ground, and the
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  ground has a very different electrical otential to a live
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  wire. So if you touch a live wire
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  while you're standing on the ground, your body connects 2
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  points with completely different voltages.
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  The electricity suddenly has a brilliant new path, and it takes
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  it straight through you. You've accidentally become the
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  circuit. You are the sock.
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  Except now you're a soaking wet sock touching both the water
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  slide and the ground at the same time, and the water is coming
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  through you whether you like it or not.
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  Birds perched on a single wire aren't touching the ground at
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  all. They're just floating up there
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  in the sky, completely isolated, minding their own business with
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  no path for electricity to follow.
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  It's not that they're protected by some kind of bird magic, it's
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  that they accidentally follow all the rules of electricity
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  perfectly without even knowing any of the rules.
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  Which is honestly quite impressive for a creature whose
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  brain is roughly the size of a walnut.
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  A small walnut. This is also why electricians
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  wear special rubber gloves and boots.
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  Rubber is a terrible conductor, meaning electricity genuinely
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  struggles to pass through it. So electricians basically borrow
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  the bird's trick on purpose, just with better fashion choices
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  and hopefully a bit more awareness of what they're doing.
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  The big lesson here is that electricity follows rules.
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  Strict, logical, completely predictable rules.
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  It needs a voltage difference and a complete path.
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  It doesn't randomly ZAP things for fun.
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  It has to have a reason to move through something, and if that
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  reason isn't there, it simply won't.
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  A bird on one wire in mid air just doesn't give it a reason.
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  The electricity moves on without a second glance.
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  Those exact same rules are what make your games console work,
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  what powers your telly, what charges your tablet, and what
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  keeps the lights on in your house.
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  The principle that keeps a bird safe on a wire is the same
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  principle that engineers use to build almost everything
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  electrical on the planet. So next time someone tells you
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  birds are simple creatures, you can tell them that birds are
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  accidentally brilliant electrical engineers and see
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  what face they make, right? You know what time it is?
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  It's quiz time. 3 questions, multiple choice.
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  I'll be watching. I won't actually be watching.
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  I have no way of watching, but imagine that I am because it'll
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  make you try harder. Question one.
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  Why is a bird usually safe when sitting on a single power line?
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  Is it A because birds have a special rubber coating on their
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  feet, B because both feet are at nearly the same voltage so
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  there's no reason for current to flow through the bird's body, or
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  C because electricity is scared of birds and just doesn't want
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  any trouble? The answer is B.
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  Both feet are at nearly the same voltage, so there's almost no
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  electrical pressure difference across the bird's body, and the
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  current stays in the wire where it belongs.
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  Although C would absolutely be my favorite nature documentary.
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  Question 2. When does a bird actually become
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  in danger of being electrocuted? Is it A when it sings too loudly
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  and the electricity gets annoyed?
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  B when it touches 2 wires or a wire and a grounded object at
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  the same time? Or C when it's eaten too many
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  chips and becomes an unusually good conductor?
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  The answer is B. When a bird accidentally
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  connects 2 points with different voltages, its body creates a
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  path for the current, and that's when the danger becomes very
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  real. Chips are generally fine for
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  birds. Probably don't test that.
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  Question three. Why do humans get electrocuted
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  more easily than birds on power lines?
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  Is it A because humans are significantly more delicious to
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  electricity? B because humans are usually
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  touching the ground, which completes the circuit, or C
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  because electricity just doesn't like people, and honestly, who
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  can blame it? The answer is B humans are
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  nearly always in contact with the ground, which is at a
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  different electrical potential to a live wire.
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  That connection completes the circuit and the current flows
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  through the body. Electricity doesn't actually
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  have opinions about people. Probably.
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  We haven't fully ruled it out. And that is today's episode of
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  the Curious Kid cast. Completely wrapped up a gigantic
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  thank you to Freddie from Cape Town for that absolutely
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  brilliant question. You've contributed to the
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  science education of children across the world, and that is
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  genuinely not a small thing. If you've got a question you'd
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  like me to answer on the show, whether it's about animals,
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  space, whether the human body, or something completely random
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  that appeared in your brain at 2:30 in the morning, head over
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  to curiouskidcast.com and send it in.
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  The weirder the better. We mean that.
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  And if you enjoyed today's episode, please share it with
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  someone, a friend, a sibling, a parent, a grandparent, A
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  neighbor, anyone who has ever looked up at birds on wires and
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  not thought to ask why. Because now you know something
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  most people don't, and that kind of knowledge is far too good to
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  keep to yourself. Don't forget to subscribe so you
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  never miss an episode. And we'll be back very soon with
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  another question that sounds completely simple and
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  absolutely, definitely isn't. I'm Charlie.
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  This has been the curious kid cast.
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  Keep asking questions, keep being curious, and whatever you
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  do, please, please don't go touching any power lines to
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  check if any of this is accurate.
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  The birds have had millions of years to figure this out.
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  You have not. Hey, we'll let your.
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  Questions rise. Lift them up to the endless sky.
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  Everyone is, as far so bright. Curious Kid cast Ignite the
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  Light.