It’s a theory that’s been passed through generations since the Empire State first became
the world's tallest building back on March 31st, 1931.
It’s said that if you make it all the way up the building’s 1,860 steps, and stand
a whopping 102 stories above the New York sidewalk, all you’d have to do to kill the
pedestrians on the street below is drop a penny.. The idea is that even a tiny object,
like a coin, can gather enough speed when dropped from a sufficiently great height that
it effectively turns into a bullet, splitting open the head of anyone unfortunate enough
to be standing underneath.
But exactly how true is this? Could the insignificant act of letting a single coin fall from a great
height carry a murder charge?
I’m Stu, this is Debunked, and we’re here to sort the truths from the myths and the
facts from the misconceptions.
So how fast would this hypothetical penny be falling when it hit some unsuspecting hypothetical
tourist on their hypothetical noggin? Well, since we’re atop the Empire State Building
in this curious caper, let’s assume that the penny we’re dropping is a standard American
one-cent coin.
Now around here...
...is where the theory starts to fall apart.
The fundamental problem with this concept is that it assumes the penny will continue
to gather speed for much longer than it actually would. In reality, falling objects can only
move so fast.
This is because the Earth is encased in a cosy layer of gases known as the atmosphere,
the portion we’re concerned with is actually called the troposphere - the lowest region
that’s closest to the ground. Everything moving around on the Earth’s surface has
to move through it, and as a result, will encounter air resistance.
As the force of gravity pulls the penny faster and faster towards the ground, the amount
of air resistance increases. Eventually, the accelerating forces will be balanced out by
the air resistance, meaning the penny won't be able to go any faster. It will have reached
its maximum speed, also known as its terminal velocity.
A penny reaches its terminal velocity after falling a mere 15m, which is slightly taller
than the letters in the Hollywood sign.
This means that a penny falling from any height exceeding 15 metres will hit the ground at
the same speed. The more astute among you will have realised that the Empire State Building
is, in fact, taller than 15m, standing proudly at an impressive 443m or 1,454 feet.
Considering the fact that the fifth floor of the Empire State Building stands at around
22m,
dropping the penny from the Observation Deck on the 86th floor is simply a waste of time
(and money, since a ticket to the Observation Deck will set you back $34).
A standard American one-cent coin weighs in at 2.5g. A penny of this weight, when dropped
from a distance of over 15m, will reach the blistering speed of around 40 km/h (or 25mph).
This isn’t even close to fast enough to kill someone, or even harm them very much
at all. It might sting a little, but you’d certainly live to bore everyone with the story
of how you got hit by a penny while walking past the Empire State Building on your Sex
and the City walking tour.
What the bloody hell was that?
Oh a penny,
I thought would have killed me!”
Part of the reason for this is that pennies are hopelessly un-aerodynamic. They are flat,
light, metal disks, so they encounter a lot of air-resistance, causing them to move and
spin erratically, which significantly slows their descent.
Furthermore, all these calculations are made on the assumption of entirely unrealistic
perfect weather conditions, and don’t take into account the likely effects that wind
would have on the coin.
Indeed, the Empire State Building itself creates updraft; when wind hits the side of the building
it is forced upward, causing anything light that is dropped off the top of the building
to be blown back up, often landing on ledges outside the upper floors. So your projectile
penny may not even make it to the ground, let alone the soft, gooey folds of a New Yorker’s
brain.
So what if we removed the effects of air-resistance altogether, and encased the entirety of the
Empire State Building...
...in an airless vacuum?
If this were even remotely possible, and, I’m afraid it isn’t,
the lack of air-resistance would allow the penny to reach speeds of around 320km/h (or
200mph.)
This might be fast enough to cause some injury to the top of a person’s head, but fortunately,
it still probably wouldn’t kill them.
Of course, you could simply opt to throw something more aerodynamic off the top of the building.
Depending on the design and quality, a ballpoint pen might remain stable enough to zip through
the air like a javelin. Scientists have been hard at work on this concept, and have predicted
that a reasonably well made pen could fall as fast as 320km/h under perfect weather conditions,
as fast as a penny in a vacuum.
Given that the tips of most pens are fairly narrow and made of metal, if one hit the top
of your head, death isn’t necessarily impossible.
Of course, if you’re really intent on assassinating someone standing outside the Empire State,
stop messing around with pennies and pens and chuck a microwave off the top.
Not that we endorse that.
We don’t, we do not endorse that.
Oh and a little fun fact, there's actually a secret 103rd floor above the official 'Top Floor'.
It has a balcony with just a waist high wall to protect visitors from falling off the edge.
But I'm afraid it's closed off to the public.
It has a balcony with just a waist high wall to protect visitors from falling off the edge.
But I'm afraid it's closed off to the public.