A medieval army laying siege to a castle could have used nearby coniferous trees as an improvised catapult to hurl diseased corpses over the wall.

busted

The Build Team began by visiting a tree plantation to determine the amount of bending force a typical conifer could withstand without breaking. Their first test, on a Gray Pine, gave a result of 2,000 pounds (907 kg); they loaded Buster into a second such tree and applied the same force, but he only fell to the ground when they released it.

Returning to the workshop, they set up some small-scale tests with saplings of three different types – Douglas-fir, redwood, and Alaskan cedar – and a miniature Buster figure. Preliminary trials showed that the fir could give the longest range for the same bending angle, so the team trimmed off the limbs and attached a tether to keep the payload in place until the right moment. With these modifications, the sapling flung the dummy all the way to the other end of the shop.

At the plantation, the team found a full-size Douglas-fir and set it up in the same way, aiming at a bouncy castle 100 feet (30 m) away with a 40-foot (12 m) balloon “wall”. With 2,400 pounds (1,089 kg) of bending force on the trunk, Buster flew almost all the way to the castle, but hit the ground just short of it. Because they were unable to hit their target even with the benefit of modern machinery and cutting off all the limbs, the team declared the myth busted.

It is possible to make a usable candle out of earwax.

busted

The Build Team collected wax from Tory’s ears and ignited it alongside paraffin and beeswax, two common materials used for candles. The earwax burned with some sparking and sputtering, whereupon the entire MythBusters crew and other volunteers were called in to provide more wax. When the team made this into a candle and lit it alongside a paraffin candle, the earwax candle burned very poorly and soon went out. They attributed this result to the fact that the material did not melt smoothly as did the paraffin, which could then easily travel up the wick to burn in the flame.

(This myth is based on a scene in the movie Shrek.)

Dipping a sleeping person’s hand in a bowl of warm water will cause him to “wet the bed” (urinate involuntarily).

busted

At the California Center for Sleep Disorders, Adam and Jamie set up a bed with a moisture-sensitive alarm. Each took a turn as a test subject, with the other ready to place the sleeper’s hand in the water once he had achieved a deep enough sleep. Jamie never reached that point, while Adam kept waking up due to his sleep apnea and ended up with his hands in an awkward position. Jamie was only able to pour the water over Adam’s hand, which soon woke him up without triggering the alarm. Crew member Matt Cordova was brought in for a third trial; five minutes after his hand was placed in the water, the alarm went off, but this was due only to water spilling out of the bowl.

It is possible to create impromptu gunpowder and use it to effectively fire a cannon made from a bamboo stalk.

busted

Grant and Tory collected the ingredients for gunpowder and began to mix them by hand in various ratios, testing them against industrial powder to find the best formulation. Meanwhile, Jessi bored out a thick bamboo stalk to use as a cannon barrel, which the Build Team wrapped with ropes to duplicate the episode more closely. They set up the cannon, with a Gorn target in front and Buster at the breech, and loaded it with ammunition and homemade powder. When they set the cannon off, the powder only burned without exploding; they achieved the same result with an actual cannon and the same powder. When they loaded the bamboo cannon with industrial powder and set it off, the resulting explosion destroyed the barrel and wrecked Buster, but the Gorn was undamaged. Finally, they built a second barrel out of bamboo, reinforced it, and fired it with the same charge, injuring Buster far worse than the Gorn and leading the team to declare the myth busted.

(This myth is based on the Star Trek episode Arena.)

A whole coconut can be sent by mail (USPS) without any packaging and arrive at its destination intact.

confirmed

Adam and Jamie addressed a coconut to themselves, stamped it, and put it in the mail. It later came back to the M5 workshop with no visible damage.

A strike-anywhere match can be lit by a bullet fired from a gun.

confirmed

Adam and Jamie set up a .45 caliber pistol and aimed it at a match head. After several shots that either missed the match or destroyed the head entirely, they were able to make the bullet lightly graze the match head and ignite it. They commented on the high degree of accuracy needed to make this shot.

Many objects that people touch every day are dirtier than a toilet seat.

confirmed

Adam and Jamie chose a total of 8 objects to test for cleanliness: toilet seat, money, kitchen sponge, hotel room remote, computer keyboard, light switch, cell phone, and shopping cart. They swabbed each surface for 10 seconds and created Petri dishes from the swabs that incubated overnight. Their first method of measurement was to count the number of microorganism colonies on each dish. They found that the toilet seat sample actually had the fewest colonies, while the kitchen sponge sample had more than they could count:

1. kitchen sponge (most colonies)
2. money
3. light switch
4. computer keyboard
5. hotel remote
6. shopping cart
7. cell phone
8. toilet seat (fewest colonies)

However, they always wanted to account for the “nastiness” or harmfulness of the types of organisms on each Petri dish, so they had a microbiologist re-rank the samples. The list was as follows.

1. kitchen sponge (most nasty)
2. money
3. light switch
4. computer keyboard
5. toilet seat
6. cell phone
7. shopping cart
8. hotel remote (least nasty)

Finally, Adam and Jamie decided they needed a larger sample size to provide better results. They enlisted a group of biology students at UC Berkeley to collect more samples from the top five dirtiest surfaces. After collecting and analyzing these samples, the final list was as follows.

1. kitchen sponge (most dirty)
2. money
3. computer keyboard
4. toilet seat
5. light switch (least dirty)

At 50 mph (80 kph), a sports car can launch off a small ramp and skip across a 100 ft (30 m) lake.

busted

To test this myth, Tory, Grant, and Jessi built dug a 100 ft trench at the end of a test track and filled it with water. They did not have the means to use a Lamborghini, as shown in the movie, but settled for a car of similar size and weight. They equipped the car to drive by remote control and drove it off a small ramp at 50 mph. Rather than skipping, the car hit nose-first and flipped end-over-end. Grant explained that the stunt in the movie was likely achieved with a platform just under the surface of the water and with weights in the car to keep it level.

(This myth came from the movie Cannonball.)

At high speeds, a sports car can skip across a 100 ft (30 m) lake.

confirmed

Tory, Grant, and Jessi again substituted an average car for a sports car, but equipped it with a nitrous oxide system to increase its top speed. Small scale tests showed that skipping worked better without a ramp, so no ramp was used for the full scale test. When the team drove the car onto the artificial lake, it skipped twice and continued driving on the other side.

A bus can jump over a 50-foot gap in a roadway, land safely on the other side, and continue driving.

busted

The Build Team acquired a bus with the same dimensions as that used in the film, then built a small-scale model of it as well as the stretch of road in question. Running at a calculated speed of 20 miles per hour, the bus plunged off the end of the road and crashed into the support posts at ground level on the other side. When the gap was halved, the bus still dropped far enough to hit the far end of the roadbed head-on. The team theorized that hidden ramps placed on either end of the gap may have helped the bus to make its jump safely. After outfitting their full-size bus for remote-control steering on an airfield, they did a speed test and found that it could go up to 58 miles per hour, rather than the 70 miles per hour depicted in the film. With the 50-foot target distance scaled down to allow for the lower top speed, they jumped the bus off a ramp; it fell far short of the target, but remained relatively intact until it hit a concrete safety barricade. Since the bus could not make the jump, the team declared the myth busted.

(This myth is based on a scene in the movie Speed.)

It is possible to smuggle contraband across borders by driving at night, at speed, without headlights.

busted

Grant, Tori, and Jessi went to an indoor go-kart course to see if they could drive in the dark. They added some signs and obstacles to better simulate a real road. Each of them first drove the course with their headlights on to get a control time. Next, they each attempted to drive the course in darkness. They sat in the dark for 20 minutes beforehand to let their eyes adjust. The results were not good: Grant went the wrong way, Jessi crashed, and Tori finished but had to drive extremely slowly. Tori also tried driving the course while wearing night-vision goggles. Although he could drive fairly well, his lack of peripheral vision and depth of field allowed him to be caught by the police (played by Jessi).

When diving in an old-time diving suite (pre-SCUBA), failure of the surface air supply will cause deadly decompression that will push the diver’s body into the helmet.

confirmed

Kari, Grant, and Tori began with a small scale test using a miniature diver made of ballistics gel. They lowered it into a diving tank at a Six Flags amusement park and found that the body of the diver was indeed pushed into the helmet when de-pressurized. Before the full scale test, Kari temporarily left the show due to her pregnancy, and a new host, Jessi, was introduced. Next, Tory built a fake diver using a plastic skeleton and pieces of pig flesh sewn around it together. Organs and fake blood were also inserted into the chest cavity. The team went to open waters and lowered the fake diver to a depth of 300 ft (91.4 m). At that depth, 135 psi (9.2 atm) of pressure was needed to equalize the suit pressure. To simulate the air line being cut, grant used a quick-release valve. To the team’s surprise, the pressure differential did indeed force organs, blood, and flesh, into the helmet, and thus, the myth was confirmed.

A water heater can explode like a rocket and shoot through the roof of a two-story house.

plausible

The MythBusters set up a three-tier scaffold to simulate a two-story house. The lowest level housed the 52 US gallon (200 L) water heater, second level contained a simulated living room, and on top was a roof built to standard California building codes. The resulting explosion from the water heater did cause it to shoot through the living room floor and the roof. It was deemed plausible because, unlike the original myth, researchers did not uncover any documented events of water heater explosions in two-story houses.

A device exists that can shoot bullets around right angle corners.

confirmed

The device does exist; kari used the device, called the “CornerShot”, to successfully shoot a target positioned around a corner.

From around a corner, it is possible to fire a gun and hit a target while only the gun is exposed.

busted

Because Grant could not see the target, all of his shots missed.

From around a corner, it is possible to fire a gun and hit a target by jumping out of the corner and shooting at the target while airborne.

plausible

Tory hit the target using this technique and landed on a mattress that had been placed to break his fall. However, chances of doing this in a real-world setting (i.e. no mattress on which to land and the target shooting back) are slim.

A person can hold onto the roof of a car, with the windows up, while the car crashes through a wall of cardboard boxes.

confirmed

Jamie stayed on the top of the car, even though he let go seconds before the car crashed through the wall. It should be noted that some boxes were hit by the front end of the rig and only one box directly hit him.

A person can hold onto the hood of a car while the car crashes through a wall of cardboard boxes.

confirmed

Adam stayed on the car despite feeling what he described was a force acting on his feet from the boxes. Upon closer inspection of the high speed footage, Adam actually let go of his grip on the hood and slid up the windshield. He then regained his grip on the hood just as he was about to fall off the car. Since the loss of his grip happened so fast for anyone to notice, this myth was deemed confirmed.

A padlock soaked in liquid nitrogen is easier to break than a padlock at room temperature.

confirmed

It took Tory four seconds using a hammer and crowbar to break a padlock at room temperature. After a second lock was sprayed with liquid nitrogen for five minutes, he was able to break it in one hit. The Build Team then tested a door locked with a deadbolt; Tory required over five minutes to smash it at room temperature, but less than two minutes after it had been frozen. Grant pointed out that the method would require so many people, and so much time and specialized equipment, that it would not be a practical or stealthy way of breaking into a building. Nevertheless, the team declared the myth confirmed.

A V-shaped snowplow is capable of perfectly bifurcating a car in a head-on collision, while the driver and the passenger both escape unharmed.

busted

A wedge entirely made of steel was made and then installed onto a rocket sled to represent the snowplow. The surrogate snowplow traveled a total distance of 770 feet (230 m) and struck the car at a speed of 550 miles per hour (890 km/h), completely splitting it along its length with a thrust of 7,500 pounds (3,400 N). Afterwards, the wedge disintegrated when the rocket sled slammed into a concrete barrier behind the car. The Build Team still regarded the myth as busted because an average motorist is highly unlikely to encounter a snowplow traveling with enough speed to destroy a car in this manner.

In 1633, an Ottoman Turk named Lagari Hasan became the first person to make a successful manned rocket flight by launching vertically to 300 meters (1,000 feet) and descending back to earth with a winged device.

busted

Grant, Tori, and Kari started with a variety of reference drawings and built small-scale rockets to see if a single- or multi-engine rocket would perform better. Despite the multi-engine design performing better, the team thought it would be simpler to build a single-engine rocket for the full-scale tests. Deciding that hang glider-like wings would be too difficult to make and use, the team instead opted to see if a parachute could be used to safely land the dummy rocketeer. The team also replaced the 140 pounds of black powder stated in the myth with 15 pounds of modern rocket propellant. When the team attempted to launch their rocket, it did get off the ground but tumbled out of control after only 100 feet. Given that the team could not successful reproduce the mythical feats even with the aid of modern technology, they called this myth busted.

A human head dipped into liquid nitrogen for five seconds can be smashed and shattered into pieces.

busted

For this test, Grant built a robot with a large hammer to simulate an object being smashed on the counter. Four heads heads were made using a mold of Kari’s bust, three made of ballistics gel, each with a skull and brain matter analog inside, and one completely made of ice. In the two control tests, the ice head shattered while the ballistics gel head (room temperature) only had its front part broken. The test for the head dipped into liquid nitrogen for five seconds showed a result seemingly in between the two control tests: parts of the head did shatter, but not completely. To achieve the results shown in the film, the third head had to be dipped in the liquid nitrogen for five minutes. The myth was technically busted at this point. But to really simulate human flesh and blood, the myth was then retested using two pig’s heads. The head dipped for only five seconds merely had its snout flattened while the one submerged for fifteen minutes did not even shatter, completely busting the myth.

(This myth is based on a scene from the film Jason X.)

A fresh Christmas tree doused with liquid nitrogen can spontaneously explode.

busted

For a control test, a Christmas tree explosion was made using a detonation cord. Then, a second Christmas tree was sprayed with liquid nitrogen. But after half a hour and with the temperature of the tree plummeting to almost −330 °F (−201.1 °C), no explosion occurred, not even after Tory shot it with buck shot bullets. The myth was busted because conifers and other kinds of cold-climate trees have air spaces outside the tree cells large enough to accommodate the expanding water as it turns into ice, preventing them from freezing and thus preventing an explosion.

It is possible to extinguish a grease fire with enough water.

confirmed

Adam called in a firefighting helicopter, which dropped 500 US gallons (1,900 L) of water on the grease fire and successfully extinguished it.

A person can detonate a block of C-4 (and escape) by placing it in a microwave oven and heating it for one minute.

busted

The Build Team set up three microwave ovens, each of which contained a different C-4 device: one unaltered block, one with wiring similar to that used in the film, and one with both wiring and a blasting cap. Using a remote-controlled bomb disposal robot, the team set each oven to run for 60 seconds at full power. The unaltered block did not heat up appreciably, while the one with only the wiring caught fire but did not detonate (though the door of that oven did burst open). The wiring/cap device exploded violently after only a few seconds of heating, due to sparks arcing across the metal wires and touching off the blasting cap. Since a person placing this bomb in a microwave would be unable to get to safety before it exploded, the team declared the myth busted.

(This myth is based on a scene from the film Grosse Pointe Blank.)

A block of cheese can be fired from a cannon with enough force to shred a ship’s sail.

confirmed

The Build Team evaluated three different cheeses for hardness, stiffness, and elasticity: Edam, smoked Gouda, and Garrotxa. They set up a canvas sail made with period-accurate materials and methods, and fired one sample of each cheese at it. Edam, the softest of the three, bounced off the sail without damaging it; Gouda, the hardest, was too brittle and broke up into fragments as soon as it left the barrel; but the Garrotxa, having the right mix of hardness and elasticity, remained intact and punched a hole in the canvas. Even though the exact type of cheese did not match the accounts, the team declared the myth confirmed.

(This myth is based on accounts of a 19th-century South American naval battle in which a Uruguayan commander was forced to use slabs of Dutch Edam instead of cannonballs when the ammunition ran out.)