Music may have charms to soothe the savage breast—but it can also do a number on flames. In the above video, a blast of sound easily conquers fire. When researchers from the Defense Advanced Research Projects Agency, or DARPA’s, placed two speakers on either side of the burning liquid fuel, the sound waves increased the air velocity and thinned the fire. As for the fuel itself, the higher velocity led to more fuel vaporization for a wider and cooler flame. Both effects made the blaze easy to snuff out.
Here’s the situation: You spot Roman attack ships headed for your shores. Do you order your troops to ready the cannons? Or–in an ancient MacGyver move–do you use a parabolic mirror, focusing the sun’s rays to set the ships on fire? Though the latter is clearly more suave, recent research has shown that the 212 B.C. legend about Archimedes’ mirror defense is unlikely: He probably pulled out the big guns instead.
Cesar Rossi, a mechanical engineer at the University of Naples in Italy, figured out the numbers. A steam cannon–like the ones Leonardo da Vinci drew in the 1400s–could use less than a tenth of a cup of water to fire a hollow clay ball, at 134 miles per hour, to hit a target 492 feet away. For comparison, an 1854 American Civil War Howitzer cannon could fire a ball about ten times farther–a little less than a mile.
Cross-posted from Cosmic Variance:
From the Seattle P.I.:
About 3 p.m. Sunday, Bellevue firefighters were called to the 17100 block of Northeast Fifth Street after neighbors saw flames and smoke.
“It appears that a glass bowl, partially filled with water and elevated on a wire rack in a sunny area of the home’s deck, provided the right conditions to focus the sunlight and start a fire,” Lt. Eric Keenan said.
They should have listened to the warnings from the ants.
Discoblog: Fire Water Gets Literal: Colorado Couple’s Tap Water Erupts in Flames
Discoblog: Only You Can Prevent Forest Fires—But Maybe You Shouldn’t
This year, Disco thought we’d get into the spirit of Halloween and dress up in a space suit. So we went to a costume store and bought a silver unitard for the occasion. But when we took the suit out of the bag, it smelled like a new shower curtain. Earlier this year, a national environmental organization found that shower curtains contained high concentrations of phthalates and released volatile organic compounds it to the air (which are all chemicals that the Environmental Protection Agency has recognized as hazardous).
Which would explain why the smell made us feel nauseous. We checked the tag to see what the unitard was made out of: 100 percent polyester, made in China.
So is this costume safe to wear today?