Garlic: Bad breath, yes ... but a bomb scare?
Dozens of passengers in Philadelphia had to be evacuated from an American
Airlines flight Tuesday after a bag checked in for the flight triggered a bomb
scare. ABC Channel 6 of Philadelphia reports fire trucks and a bomb squad were
called in, adding that it took about two hours for the situation to be resolved.
The offending item? The "suspicious bag" included garlic paste, which apparently
was detected by explosives detection devices.
Forget food, United's Ted to try retail sales
Fly United's low-fare unit Ted, and you'll be able to buy more than just lunch or dinner. One week from today,
the carrier will begin hawking coloring books, stuffed animals, poker kits and other merchandise on flights
longer than 2 1/2 hours, reports the Rocky Mountain News. The paper says it's the first time a major U.S.
carrier has tried to sell retail merchandise on domestic flights, writing that the move "represents another
effort by United to increase revenues and bolster its bottom line as it attempts to exit bankruptcy protection
in February." Prices for ‘the retail goods range from $5 to $25. "We are making Ted even more fun," said
United spokeswoman Jean Medina. "It's an opportunity for customers to buy on board things they may have
forgotten, like a toothbrush, or even to buy last-minute gifts, like a box of candy or a bracelet." However,
Sara Nelson Dela Cruz, spokeswoman for the Association of Flight Attendants, says the union has some
concerns about the plan. "It's another thing to add to our duties, and our primary concern is safety and
security of the flight," she says. Among the other items for sale: Origami kits ($5), crossword or Sudoku
books ($10), window seat book featuring pictures from the air ($15), sterling silver heart bracelet ($20) and
compact sunglasses ($25).
Science snapshot: London's bridge is swinging 'round
Over hill and over dale, soldiers march everywhere. Except bridges. There, synchronized steps might set a
bridge to swinging up and down and then apart, so instead soldiers break step. The flip side of this
phenomena seems to have afflicted London's Millennium Bridge, which tourists' steps somehow set to
swinging sideways in wild fashion, only a few days into its 2000 opening. The force of feet on a bridge isn't
the worry, rather it is their rhythm, says Cornell University's Steve Strogatz. If the frequency of the marchers
matches the bridge's own structural frequency, this "resonance" may begin to shake the whole works up and
down. This seems to have happened to cavalry troops who famously collapsed a bridge near Manchester
England in 1831. But on the Millennium Bridge, the situation was a little trickier, Strogatz writes in the current
Nature. For one thing, the bridge started oscillating wildly sideways instead of up-and-down. The engineering
firm that designed the bridge determined that it took about 160 walkers to set the structure swaying, and that
its sideways resonance frequency, unfortunately, seemed to match two footsteps a second -- a natural stride.
But all those tourists were walking across randomly, so how did they fall into rhythm and set the bridge to
swaying? "That's what makes it interesting," says Strogatz, an expert in natural synchronization, an area of
study that encompasses the coordinated flashes of fireflies and fatal heartbeats. His analysis shows that the
bridge, "does not move until the walkers cross a certain threshold and then it really takes off." What happens
at that threshold -- about 160 walkers -- is that just by chance enough will randomly step down simultaneously
to give a very small sideways motion to the bridge, via resonance. That tiny initial sway sets more people to
alter their step to match it, says Strogatz. The neat part is they do this unconsciously, he adds, with the
resultantly larger swing setting the bridge to swaying even more, making more people join, until, "people are
actually changing their stance, looking like novice ice skaters," he says. The bridge designers damped down
the swing by bulwarking the bridge. While some blamed its novel suspension design for the sway, its
sideways resonance swing could have happened to any relatively loose bridge if enough people walked over it, Strogatz
says. "Anywhere you have crowds, you can have some interesting things happen."
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