Wednesday, November 10, 2010

Contrails and cocktails*

Today I was reminded of an old Cary Grant/Leslie Caron movie from the '60s called Father Goose. It's set during the war in the Pacific on a tropical Island. Leslie Caron steps off the bank of a creek and gets bitten by a snake. She and her student rush back to Cary Grant and she starts drinking to dull the pain of dying of snake bite. When she continues to not die while getting increasingly drunk and maudlin the student finally goes down to the creek to see what kind of snake bit her. (Spoiler alert) It was a stick. She brings back the stick with thorns on it to show it to Cary Grant and he says, "That's not a snake." And the little girl says, "But it looks like a snake!" and Cary Grant tilts his head and squints at it and says, "That looks like a snake!" And Leslie Caron doesn't die and just has a hangover instead. Now I have to tell you that when I watched this movie I was extremely bothered by the fact that nobody questioned the presence of a poisonous snake on that island. I knew the story of the invasion of the brown tree snake on Guam and was skeptical that there were any poisonous snakes at all in fresh water on small isolated Pacific Islands during World War II. The brown tree snake wasn't accidentally introduced to all those little islands until AFTER World War II. And it's venomous, but not deadly. But anyway, that was the plot. Overreacting that a stick was a snake when any herpetologist could have told them there are no snakes.

There wasn't a missile launched off the coast of California yesterday. And there wasn't a lot of press about a missile in the world news. But there was a lot of buzz around the US about a contrail a news helicopter filmed around sunset yesterday. He thought it looked like a missile launch. The Navy said they didn't fire a missile. The Air Force said they didn't see any missiles on radar. And no oceanographers came forward to claim a mystery missile splashed down in the Pacific disturbing the great garbage patch.

I read the progression of news on IEEE Spectrum, which I tend to trust as a more scientific source than most others. I follow them on Twitter. They post links to new stories when something is going on. (I used to fork over $105 a year dues to be a member of the IEEE so I know it's actually a funded institute with paid writers. That's the Institute of Electrical and Electronics Engineers in case you wondered. It's one of the largest professional organizations in the world. And yes, they let physicists in too if you are working as an electronics engineer and have a member vouch for you. I notice Dr. Ian O'Neil cites the IEEE in his article too.) They started out with "Whose Missile Was Launched 35 miles West of Los Angeles?" But they quickly realized that "whose missile?" was the wrong question. One of the first things the author did was check to see if there were any official warnings to mariners and pilots to watch out for something shooting up through their airspace. There was nothing. The Navy doesn't just shoot stuff into space without making sure everybody is cleared out of the way. One of the commenters in an early IEEE story said the same thing I was wondering, where's it supposed to have come down? Seems important but nobody really addressed it in any of the stories I read.  So it was pretty easy to eliminate a missile as the source of this trail in the sky at sunset. The right question was "what makes this contrail look like a missile launch?" Then it was just  question of finding an expert in contrails to see if what was unusual to our untrained eyes was normal to them. Yep. Normal. Just an airplane.

Conveniently enough I just happened to reread an old Bad Astronomy article earlier today explaning why the moon looks so big on the horizon. Apparently our brains suck at judging size and distance in the sky. So I was primed for the thorough explanation by the contrail specialist. Good day for the critical thought process.

Contrail from the Atlas V Rocket that launched the Solar Dynamics Observatory. Why is it so squiggly?  Because the engines are moving around to keep the rocket going straight? I don't know enough about rockets or  the atmosphere to really say. This contrail appeared in the hot moist air on top of a cold dry layer -- evidenced by the sundog. The conditions right for a contrail were only in that one layer. Which makes me think a real missile would be more likely to exhibit a limited contrail and not a continuous one like you'd get if a jet just flew along in that same layer horizontally. Which is what the news footage of the supposed missile launch showed -- a very long contrail.
Contrails at sunset can look like a lot of things they aren't. These aren't meteors.

*Somebody should make up a cocktail called The Contrail. It could be huge in bars in LA this week.


  1. Ahhh, clarity, rationality, and a complete lack of filling in the gaps in our knowledge with bullshit. So nice. So rare. Thanks.

  2. How sadly boring. I thought I might wake up to a world in which North Korea had gotten an old Soviet submarine and was doing some fiercely foolish saber rattling! But no, the contrail explanation is far too reasonable... It's just an ordinary object seen from an interesting angle.

    As for the movie, at least the writers resolved it properly: no snake, just a jumped-to conclusion.

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  4. I helpfully posted a link to... the exact same page you already linked to.

  5. Great minds think alike :)

    Thanks for all the nice comments everybody. I appreciate it. Makes up for the bad dream I had last night that a cousin saw a pair of Coastal Taipans poke their heads out from under the passenger's seat of a car she had shipped from overseas. I was trying to call my herpetologist friend Dr. Means to find out where to go to prevent the snakes from escaping and get him to catch them. All this while driving the car with the snakes loose in there. I couldn't stop for fear they'd slither out and disappear on the right of way. I was so worried they'd become an invasive species and displace our native rattlesnakes, plus, you know, badass snakes loose in the car! What a nightmare! So no more researching stowaway venomous snakes at bedtime.