Episode 161: Blue Ice
Air Date: April 13, 2011
By intentionally causing a gas leak in a room and inserting a magazine in a toaster, it is possible to cause a large explosion (as shown in the movie Bourne Supremacy).
busted
Adam and Jamie began by placing magazines of various thicknesses in toasters and timing how long they took to catch fire. The thinnest and fastest to burn, similar to common newsprint or comic books, took roughly 2 minutes to catch a flame rather than the 20-30 seconds observed in the film. Small-scale tests with mixtures of methane and air indicated that a methane level as low as 6% (the bottom end of its flammability range) could trigger a noticeable explosion.
For full-scale testing, they built a replica of Jason Bourne’s apartment, including the toaster, magazine, and methane supply. Their first attempt at an explosion, using the circumstances shown in the movie, did not give any significant reaction, and the myth was declared busted. A second attempt with a higher gas concentration and a fireplace starter log as the ignition source led to an energetic fire, but no explosion. Adam and Jamie made one last attempt, using enough methane to achieve a 9% concentration (the center of the flammability range) and a set of fans and diffuser hoses to mix the gas and air thoroughly. This time, they were able to get one wall to blow out and set the apartment on fire.
If the contents of an airplane toilet are jettisoned mid-flight, they can freeze into a solid mass capable of inflicting severe damage upon hitting the ground.
confirmed
To set the stage for this myth, Kari spoke to an airplane technician and learned that although a pilot cannot dump the toilet mid-flight, the contents could leak out if multiple valves and seals failed.
For their tests, the Build Team made a small section of an airplane fuselage, including a lavatory service outlet (designed to suffer a slow or sudden leak, as needed). They took this rig to a wind tunnel at NASA designed for high-altitude simulation (including low air-temperature). When the toilet was dumped all at once, the fluid quickly atomized in the wind, leaving only a thin film to freeze on the fuselage. However, a slow leak allowed the ice to build up into a large mass that did not break loose until the rig “descended” (i.e. the air temperature in the wind tunnel was increased) to 12,000 feet (3,650 meters).
To determine the ability of such a chunk of ice to survive a fall to earth, Kari dropped a 35-pound (16 kg) block of ice from an airplane at 12,000 feet. Grant and Tory tracked it from the ground while Kari skydived. The block remained intact and embedded itself deeply upon impact, prompting the team to declare the myth confirmed, although unlikely due to the multiple mechanical failures needed to achieve the result.
In the “blue ice” story I noted one problem in the 12,000 foot drop test: the chunk of ice they used was a frozen solid hunk. However, the ice formed from a slow leak of the toilet system would probably not be quite so solid. It would probably form in layers and most likely have holes in it.
I’m wondering how this non-uniformity would affect the result. I’d expect that winds as it fell to introduce stresses which would cause it to break apart into smaller chunks.
I agree. The irregular and jagged edges of the “blue ice” would offer resistance and would, most probably, break off as it fell at high speed and as the temperature rose. I don’t think that it would react the same way as the block of ice.
I agree, the ice sample was not consistent with the ice formed in the test at NASA. The ice there was layered and rough both of which would increase the effects of friction as the ice falls increasing the possibility or breakup during it’s fall.
In the “Bourne” story there was couple differences betwen movie and Mythbusters experiment. In europe insted 110V is 220V that twice much (ignition). Second difference is in construction of the buildings. In Mythbusters epizode, building was made from wood and drywall and explosion blow up side of structure. In europe buildings is made out of concrette and bricks so it is heavier and withstand Moore psi. We know More psi more BOOOM.
I disagree with your comment about voltage. The fire in the toaster is caused by heat, not by voltage. A European toaster will heat a European slice of bread at the same speed as an American toaster heating an American piece of bread. Voltage is irrelevant. Also, I don’t think a concrete building will produce more “boom” because it can withstand more pressure. That’s like saying. The concrete walls will withstand more pressure, and may cause the windows and doors to fail first, but the “boom” depends on the flammability of the fuel/air mixture, not the structure of the building.
The voltage is irrelevant. Ohms law tells us that Volts x Amps = Watts. A typical toaster runs 1000 W; at 120V it would draw 8.3A, at 220V it would only draw 4.5A. (European appliances are actually more efficient because they run on 220V.)
All of the above comments about voltage/amperage/wattage are irrelevant as it was the burning paper in the toaster which was the ignition source!!!
For the “Bourne” story, I think it would have been a better final test to construct a slightly tougher house with inner walls that could channel the explosion, and using the first tested magazine with a 12 min ignition time, let the house fill with gas until the magazine ignites. Then testing to see if the explosion would create a shockwave that could knock people down standing outside.
I LIKE THE MYTHBUSTERS!
What I want to know is, how did they get a toaster to “toast” for anything close to 12 minutes? Wouldn’t the MB lads have to repeatedly push the “plunger” down? This wasn’t mentioned in the show.