Latest MythBusters Results

A person firing a gun can accidentally kill himself if his bullet ricochets off three surfaces and returns to him.

busted

Adam and Jamie set up three steel plates at 90-degree angles, along with a .45 caliber pistol and a cardboard cutout of Jamie behind it. In three trials with different types of ammunition (unjacketed lead, full metal jacket, and total metal jacket) all of the bullets fragmented after striking the first plate. A fourth trial, using a hardened steel ball bearing in a bullet casing, led to three ricochets and a hit on the shooter; however, the projectile struck at a less-than-lethal speed.

Other materials were then investigated for use as ricochet surfaces, starting with measurements of ricochet angles and speeds from only one plate. Cinder block pavers were chosen over lead due to the latter’s tendency to make bullets tumble and lose too much speed. When Adam and Jamie set up three pavers and fired a total metal jecket round, they observed three ricochets and a less-than-lethal hit on the Jamie cutout.

Finally, the MythBusters bent a piece of metal plumbing pipe into a curve to serve as a bullet guide, firing into one end toward a block of ballistic gelatin at the other end. A 46-inch (117 cm) diameter curve, forming nearly a full circle, resulted in lethal speed and penetration on the target. Adam and Jamie declared the myth busted, owing to the slow speed of the bullet after three ricochets.

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.

A person can wet his hand and briefly dip it into molten lead without injury.

confirmed

Adam and Jamie did some research on the Leidenfrost effect, in which cool water vaporizing on a very hot surface generates a layer of vapor that temporarily insulates against high temperature. They melted some lead in a crucible and heated it to 700 degrees Fahrenheit, then dipped a raw, wetted sausage; it emerged partially cooked and with some particles of lead adhering to it. After they raised the temperature to 850 degrees Fahrenheit, the sausage could be dipped and removed unscathed, since the lead was now hot enough not to solidify on contact. Finally, Adam and Jamie dipped their own fingers into the liquid – a pinky and an index for Jamie, four fingers at once for Adam – and brought them out unscathed.

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.

It is feasible for a soda can to be contaminated with rat urine and subsequently transmit deadly viruses to humans.

busted

To create a control sample, Adam and Jamie spread out 1,000 aluminum soda cans, cleaned the top surfaces of the cans, and released 40 rats to walk on them for 90 minutes. Viewing the cans under a black light clearly showed that many of them became contaminated with rat urine. Next, they collected 1,000 cans from a variety of locations across San Francisco. Viewing these cans under a black light revealed that most of them also had organic substances on them, but it was not clear what those substances were. To find out what was on the cans, Adam and Jamie took swabbed samples to UC Berkeley, where a mass spectrometer was used to identify the chemical compounds. As expected, the control contained 15 proteins that indicated rat urine. However, the test sample did not contain any compounds indicating rat urine. Furthermore, a professor of epidemiology at UC Berkeley explained that any dangerous viruses contained in rat urine would not survive on the exposed tops of aluminum cans.

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.