Poolside at Las Vegas’s Vdara hotel is a dangerous place to be. That’s according to one tourist who claims he almost had his hair singed off by a “death ray”—the term used by some hotel employees—reflected from hotel’s shiny facade.
The hotel’s spokesperson would understandably prefer to use the term “hot spot” or “solar convergence” to describe the spot near the pool where the sunlight reflects off the building’s side. Hotel guests say they have seen plastic cups and bags melt from the heat of the ray. The Review-Journal was tipped off to the problem by the story of a poolside lounger named Bill Pintas from Chicago:
[Pintas] became so uncomfortably hot that he leaped up to move. He tried to put on his flip-flop sandals but, inexplicably, they were too hot to touch. So he ran barefoot to the shade. “I was effectively being cooked,” Pintas said. “I started running as fast as I could without looking like a lunatic.” Then he smelled an odor, and realized it was coming from his head, where a bit of hair had been scorched.
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.
Male cichlid fish apparently don’t like what they see in the mirror–in fact, they dislike their own reflections even more than enemy fish, according to new research published in Biology Letters.
“[The] fish readily attack other males as well as mirror images of themselves, posturing and lunging with the same aggression… the reflection-fighting males show heightened activity in [the amygdala,] a part of the brain associated with fear and other negative reactions in vertebrates, [Stanford University researchers] have found. Tangling with a real male doesn’t stir up that response.”