Shallow Thoughts : : 05

Akkana's Musings on Open Source Computing and Technology, Science, and Nature.

Sun, 05 Sep 2004

Año Nuevo: Elephants to Weasels

Dave took me to Año Nuevo for my birthday (and to escape the September heat). It's up the coast from Santa Cruz, really not that far from home, but somehow I'd never been there.

The park is famous for elephant seals, and during the breeding season it's necessary to make a reservation and go on a guided tour, so the tourists don't disturb the seals -- and vice versa (the male seals can get very aggressive and territorial during mating season). But during the off season, things are much lower key, the seals are moulting (which means they spend most of their time lying around on the beach) and you can get fairly close to them.

Volunteers man the observing stations at the ends of the trail spurs, and provide information on the elephant seals and other marine mammals.

Most of the seals were so inert that one might wonder if they were actually alive. One big bull, flopped in a nest of seaweed on a beach away from the others, looked particularly lifeless, though occasionally his sides would move as he breathed. Apparently the birds were fooled: one gull, poking through the nearby seaweed, hopped up onto the bull's side, perhaps thinking it was a rock, and the bull exploded into life, snapping at the gull as it hastily made its escape.

Harbor seals, California sea lions and Stellar's sea lions live on the island and make a huge and constant racket with their barking; and a couple of sea otters have been spotted nearby, but nobody had seen them today, unfortunately. Birds are plentiful: I bagged (photographically) several new birds, including Heermann's Gulls and sanderlings, and also got some decent shots of pelicans and gulls in flight.

But the highlight was neither bird nor marine. Dave spotted it first, and pointed. It looked like a squirrel -- a rather tall, skinny squirrel with a white belly -- but we don't have squirrels colored like red foxes here in California. Then the animal came down off its haunches and bounded across the trail and into some tall grass, waving its long, thin, and distinctly non-squirrelish black tipped tail. A long-tailed weasel! The first I'd ever seen. It was a nice birthday present.

[ 23:14 Sep 05, 2004    More nature | permalink to this entry | ]

LAX Shut Down by Exploding Flashlight

We've been reading for two days now the story of how LAX (one of the nation's busiest airports) was closed down for several hours after a flashlight exploded while it was being examined by a security screener.

I'm still waiting for details. Doesn't this story seem a bit odd? Isn't it fairly unusual for flashlights to explode? Wouldn't you think some reporter, while writing up this story, might think that readers might wonder whether their flashlights were at risk of blowing up, and might want to report on what specific circumstances caused this incident and how to avoid it?

The SF Chron story has the most detail I've seen so far, which still isn't much:

The Los Angeles Police Department bomb squad examined the flashlight and determined the explosion occurred because the batteries inside had eroded.
That still leaves me wondering: what sort of battery, and how big? How badly eroded? Is this something we should be checking for in our flashlights? What was the screener doing with the flashlight which caused it to explode right then?

A web search on "flashlight batteries explosion" doesn't turn up much more information. There are lots of pages warning against trying to recharge regular (non-rechargeable) alkaline batteries since they explode. We know lithium-ion and lithium-polymer batteries can explode, but I've never seen a flashlight which uses them.

I did find one NIOSH Fact Sheet called "EXPLODING FLASHLIGHTS: ARE THEY A SERIOUS THREAT TO WORKER SAFETY?", which mentions hydrogen gas being produced in zinc/carbon batteries and alkaline batteries as the zinc electrode corrodes in the aqueous electrolyte, and that it's more likely to happen if batteries of different types, brands, or ages are mixed.

Googling for "flashlight batteries exploding" gets a bit more, mostly recall notices for specific flashlights shipped with batteries which might explode.

Still seems strange that it doesn't seem to have occurred to any of the reporters covering the LAX incident to ask about this and find out what happened in this particular case. I wonder -- is this another "fox terrier", where someone writes an initial story and everyone else just paraphrases it without adding anything? Certainly the new stories coming out don't seem to add anything to the initial report yesterday morning. Do reporters not ask questions any more, and journalism schools merely instruct on different ways of re-wording a press release?

(Stephen Gould wrote about wondering why so many books mentioned that Eophippus, the "dawn horse", was the size of a fox terrier. Why that specific breed? Upon investigation, he was able to trace the origins of the comparison, and show that successive authors merely repeated the assertion verbatim. Unfortunately, the syndrome works just as effectively in cases of missing or incorrect information, as long as authors are willing to repeat stories without checking them.)

[ 12:53 Sep 05, 2004    More headlines | permalink to this entry | ]