None of the below stunts requires magic or ancient mystical mastery of your body's inner energies. What they do require is lots of practice guided by someone who knows what the hell he's doing.
In other words, do not get drunk and try these just because this article explained how they're done. You can totally kill yourself if you do them wrong. Seriously.
As the name may indicate, sword swallowing is basically when a performer shoves a blade down his gullet, sometimes deep enough to enter the stomach and scramble undigested Toaster Strudels. Anyone unfamiliar with the trick would have to assume that it's some kind of illusion, because it's pretty hard to believe that someone could jab at his innards with a goddamn sword without incurring some breathtakingly serious injury.
The trick has been impressing crowds since Old Testament days; the stunt originated in India over 4000 years ago, making it one of the earliest and most impressive things to come out of the subcontinent.
So, they use a trick sword made out of taffy or something, right?
Nope, you can totally do it with a real sword. As it turns out, the only trick to deep-throating a sword is overcoming your gag reflex. When something enters our esophagus, it contracts to push it down toward the stomach. This reaction occurs automatically, whether we are downing a burger and fries or 22 inches of forged steel.
"I think I see the problem right here."
Problems tend to arise when your esophagus contracts around the latter, so the entire trick to sword swallowing is to slowly (usually over a few years) train yourself to control your gag reflex. If stopping an automatic reflex sounds impossible, just ask any contact lens wearer. The first time you try to touch your eyeball with your finger, your eyelids reflexively slam shut. But after a few months of inserting contacts every morning, you get to where you can jab you finger right in there without so much as a twitch. It's just a matter of concentration plus repetition.
So once you've gotten control of your gag reflex, it's just a matter of tilting your head back at a 90-degree angle (so that your GI tract is straightened out), and then you've got a more or less straight path for the blade (or whatever) to slip down your throat. You do have to do it slowly -- your GI tract still isn't perfectly straight so you're kind of using the sword to gently nudge your internal organs out of the way.
AGAIN: DO NOT ACTUALLY DO THIS.
Needless to say, the swords used in this trick are usually dull, unless the performer has a death wish. Of course, performers do try to top one another, doing things like using multiple swords, which as you may imagine is fantastically dangerous. Particularly when you get to the whole "shifting internal organs" part of the trick.
The only thing missing here is one giant sword for America.
Fire eating has been a favorite at freak shows and circuses for centuries, as well as by drunken frat guys looking to impress girls at a party just moments before a screaming trip to the emergency room.
But once again, it's all in the technique, and understanding something about physics.
The trick begins when the performer dips a specialized torch into fuel and lights it. He then takes a broad stance and tilts his head back at a 90-degree angle (which you'll remember was also the first step to sword swallowing, but it's done here for a different reason).
The picture up there tells the story. Heat rises and fire goes up -- that's why you can hold your fingers on either side of a candle but put a finger right over the flame and you'll be in tears. Likewise, the flame coming off the end of the torch wants nothing more than to burn your face into Eric Stoltz from Mask, but you can safely get it into your mouth if you give the heat a perfect, vertical, invisible chimney to rise up out of.
But if the angle is wrong, God help you.
While lowering the flame, the performer also needs to slowly exhale in a steady stream. This is another strategy to keep the heat of the flame away from the face by blowing it up and away, but there is another, much more crucial reason:
If the performer inhales, the fire is going to get sucked right into his lungs and roast his insides.
Imagine this guy's stomach lining in a microwave. Nobody wants that.
If everything has been done up to this point without a burntacular injury, the fire has finally made its way into the performer's mouth. Then he closes his lips around the flame without touching them to the neck of the torch -- at this point the torch is red-hot and would melt his lips together like a soldering iron -- and with one last, quick exhale he can extinguish the fire.
Human flesh is fragile and easily damaged, so how is it that some people can hurl their hands and arms at stacks of wood boards and concrete blocks and make them look like they're made out of Styrofoam? Hell, even children can do it.
"TRY TAKING MY XBOX NOW, MOM."
Well, as it turns out, block breaking has less to do with strength and more to do with knowing the physics behind this feat.
It's a well-known scientific fact that breaking bricks makes you look suspiciously like Gary Busey.
See, every time you see this trick done, the blocks are suspended by dividers on either side that hold up the very edges of the blocks or boards. This part is crucial and is the reason why karate masters aren't tearing apart skyscrapers and sidewalks with their bare hands. For the blocks to break, there must be enough space beneath them for them to bend.
All materials flex and bend to some degree when impacted, even cement. That's part of what makes something a good building material; you want it to give a little. It's this small but important flex made by the blocks that allows you to break them.
As Bruce Lee -- or rather, the people who fought Bruce Lee -- can tell you, the karate chop is one of the most efficient movements the human body can do, exerting thousands of newtons of force. If you hit the blocks in the exact middle and -- this part is important -- then follow through with a pushing motion to complete the chop, it prevents the blocks from rebounding from that bend. So the break hinges on this critical follow-through.
This is why you won't (necessarily) shatter every bone in your hand by trying to chop through concrete. But just to be clear: The technique is everything. This still shouldn't be attempted by anyone who hasn't been trained professionally unless you're not planning on using your hand for the rest of the year.
The nurse will not be impressed.