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Does any of you folks know if your local bats colonies circle clockwise or counterclockwise when they leave their caves at dusk? A good number of caves in the northern hemisphere are reported on the net to have large colonies that circle counterclockwise, but I think I remember two colonies here in Alabama that circle clockwise.
In particular, have any of you folks beneath us noticed the direction of the circle of your bats? Thank you.
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Sorry, milum, I am unable to help. To the best of my knowledge, NZ's bats ( both species, the only native non-aquatic mammals up here) all live in the South Island, and I haven't been up there in years.
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Geez. milo! The only place I ever in my life saw a swarm of bats was when I was in the
Philippines, and the huge University of Santo Tomas building had hundreds of small cracks
from many minor earthquakes from which at dusk would come hundreds and hundreds of
bats. I don't recall their circling at all, just dispersing in every direction very quickly.
I can't think of any reason why they should circle in either direction. Their prey insects
were distributed randomly, I'm sure. Not like migratory waterfowl that I one year watched
over Susquehannah River, Just below the Conowingo Dam, circling to see which one of them
was the fastest and going to be point man (or woman) Offhand, I think they tended to fly
counter-clock wise, but I wouldn't swear to it. And anyway, all they were doing was settling
who was going to lead, not which direction they were going to head in.
What possible reason can you think of why bats should circle?
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Sorry, milum, I am unable to help. To the best of my knowledge, NZ's bats ( both species, the only native non-aquatic mammals up here) all live in the South Island, and I haven't been up there in years.
Well, I used to live up there, and I've seen bats coming and going. Never seen them swarming or circling, though.
Is this a bit like water going down the plug hole?
- Pfranz
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a bit like water going down the plug hole?
Or down the drain, for that matter. Parbly. One of those things that people believe even though the phenomena are too small to be affected by Coriolis forces.
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Well, from the bat's point of view, he's going clockwise.
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from the bat's point of view
How can you say that, Dub'? Bats don't have clocks.
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Geez, Mr. Milo. I wish I could remember which direction the cyclone of bats I observed last fall was going. Seems like it was counterclock-wise, but they could have been doing both it was that crazy.
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from the bat's point of viewHow can you say that, Dub'? Bats don't have clocks.I didn't say he knew he was going clockwise; I said his point of view would be clockwise. Clockwise is clockwise, whether you know you're movin' that way or not.  Take this as a fact from one who has no natural sense of direction.
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This clock-wise bat of yours; is he looking up or down?
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Just a-wondering....
Is 'counter-clockwise' the universal phrase in the US? Over here we'd normally say 'anti-clockwise'. Doesn't seem to make any difference to the meaning as you'd get that from the context, but as it was the first time I'd seen it, it set me wondering...
What's the verdict Down Under?
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anti-clockwise here, although the main clock in my house runs in the direction traditoinally called anti-clockwise.
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We actually have a perfectly normal alarm clock which, through some twist of fate, runs backwards (counter- or anti- clockwise) in perfect time. That is, the numbers on the face have now become meaningless, but the hands always read the correct position when it's seen in a mirror. I love it because it's not supposed to run backwards, and it actually ran forward for a long time. No one knows why it switched but I keep it going, and re-set it twice a year for Daylight Saving Time. I admire it because it's just been so obstinately ignoring the way it was designed to work!!!
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And I admire your clock, too, Bean. Is this a highly unusual phenomenon among clocks? Is it unique? I mean, is it unique for a clock set up to go clockwise to break independent and reverse direction on its own? If unique, you could submit your clock to Ripley's.
I don't like the sound of anti-clockwise as much as counter-clockwise simple because of the alliterative loss in anti-clockwise. But it's always useful to have another term.
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Is this Information or an Announcement?
I've lived above and below, and always used to watch dogs in both hemispheres to see which way they turned around before settling down. Not to mention faucets and drains. No conclusions reached. Guess they were too small. Never saw enough bats at one time to notice.
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AnnaS:
This is Anti-Information and Counter-Announcement.
On dogs:
One one dog:
Nikita, our now gone-to-dog-heaven husky, always turned counter-clockwise before settling down. Huskies are from the Northern hemisphere; they know nothing about and are unaffected by the Coriolus Effect.
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Do hurricanes "know" about it?
Depending on what you mean by "know", yes they do. Dogs, on the other hand, are small scale phenomena and *don't know about Coriolis forces.
Regarding clocks: some electric clocks have a little knob to twist to get them started. You can twist it either way and the motor will happily turn in the direction imposed upon it.
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Hey, we're out of school due to slush. Yes, slush. Were I in NY, we'd have a honkin' big martini, stirred anti-clockwise, which sounds like slowing down time, just because you spelled Coriolis correctly and I didn't.
Hey, do people in the Southern hemisphere stir their pots anti-clockwise or clockwise? If this is a yart, please advise, but I can't recall our discussing how Southern hemisphere beings stir their pots.
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Probably depend on whether or not they were left-handed, WW.  Slush??!! Oh, to be in the South (of the Northern hemisphere) again.
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Of course bats that live in church steeples would be clock wise.
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"Of course bats that live in church steeples would be clock wise."
Unless they were in the habit of going widdershins.
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the habit of going widdershins
It would seem natural, bats being normally indisposed to being sungates.
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Hwæt hwæt? No capisce sungates?
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"No capisce sungates?"
Nope. Are ya gonna enlighten me, or leave me twisting in the linguistic wind? And which way would I twist in the northern hemisphere, anyway?
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Twist both ways, birdseed, and see which way feels most natural to you.
I tried it and I can tell you for a fact I am WiddershinsWind.
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Bats dinna gae oot inna sun.
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twisting in the linguistic wind
Non tempestatispicem eges ut scias e quo parte flat ventus.
Sungates is the other way round from widdershins.
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"Bats dinna gae oot inna sun."
Well OK, it kinda makes sense now. Is sungates really a word? I couldna find it in me dictionary, laddies.
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I checked onelook and nada there. But upon googling "sungates" and "direction" found one entry, a long discourse from (supposedly) the Domestic Annals of Scotland, which I'll paste below: rest. It was alleged that, twenty-two years ago, she had been found sitting in a field of green corn before sun-rising, when, being asked what she was doing, she said: ‘I have been peeling the blades of the corn: I find it will be ane dear year; the blade of the corn grows withershins [contrary to the course of the sun]: when it grows sungates about [in the direction of the sun’s course], it will be ane cheap year.’http://www.electricscotland.com/history/domestic/vol1ch8c.htm
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Leaving us to wonder whether a cheap year or a dear year is preferable.
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Corn seller wants a dear year, buyer wants a cheap year. Widdeershins remindes me of
German "wieder" which can mean "against" but I can't figure out the "shins".
The American Heritage® Dictionary of the English Language: Fourth Edition. 2000.
widdershins
SYLLABICATION:
wid·der·shins
PRONUNCIATION:
wdr-shnz
VARIANT FORMS:
or with·er·shins (wth-)
ADVERB:
In a contrary or counterclockwise direction: “The coracle whirled round,
clockwise, then widdershins” (Anthony Bailey).
ETYMOLOGY:
Middle Low German weddersinnes, from Middle High German widersinnes :
wider, back (from Old High German widar; see wi- in Appendix I) + sinnes,
in the direction of (from sin, direction, from Old High German; see sent- in
Appendix I).
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German "wieder" which can mean "against"
Actually, that's "wider", and it also surfaces in "withstand". Anglo-Saxon was "wið". As regards the "shins" part, that's explained in the dictionary along with the rest. It means "sense" or "direction", which I guess looks weird to English speakers, but in German, "clockwise" is "Uhrzeigersinn" ("in the direction of the clockpointers" or hands).
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in the direction of the clockpointers
And the clockpointers go that way because that's the way the shadow went on the sundial face.
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However, the German "der Widder" (ram or Aries) has nothing to do with this whatsoever, no matter how contrary those two species can be at times.
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... the clockpointers go that way because that's the way the shadow went on the sundial face
Do the shadows on a sundial in the southern hemisphere march "clockwise," too? (Don't quibble; you know what I mean !)
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shadows on a sundial in the southern hemisphere march "clockwise,"
No, assuming I know what you mean.
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...do shadows on a sundial in the southern hemisphere march "clockwise?" (don't quibble, you know what I mean)
No, assuming I know what you mean.
Clarification: "clockwise" = looking at a circle from above, starting at the top and moving to the right around it
Which means that if "clockwise" is defined from sundial-shadow motion, it's linguistic-based evidence that clocks were invented (read "modern civilization arose") in the northern hemisphere. Yes?
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And it's not really belaboring the obvious. It's pointing out interesting evidence. (I don't know anything about the history of clock making, but your point is interesting enough that I'm about to google the subject. )
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I have been privileged to see the famous bat colony of Austin, Texas, emerge--once. I was too awed by the sheer numbers (up to a million and a half) to actually notice whether they wheeled clockwise or not, but as I cast my mind back, the image seems to be clockwise. Here's a link that explains about drag, lift, and thrust. Possibly these are subject to the Coriolis effect. http://www.ucmp.berkeley.edu/vertebrates/flight/physics.htmlHere is a link to the first of 5 or 6 pictures of them emerging. But if anyone can tell which way, you're a better observer than I am. http://www.pbase.com/image/264541
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Possibly these are subject to the Coriolis effect.
The reason that small scale phenomena don't show a noticeable correlation to Coriolis forces is that the Coriolis forces are small compared to other conditions. In the case of the sink drain, filling the sink from an off center tap will set up motion in the water that will not damp out before the drain is opened. If the water is circulating clockwise it will go down the drain clockwise. In the case of tornadoes, local topography will have a greater effect on the air flow than Coriolis forces will. The same is true for any aerodynamic forces that the bats will experience.
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Here is a very long list of links to bat sites. Well worth browsing. I found one picture of a lot of bats flying at dusk, but they did not appear to be circling. http://www.batbox.org/old_bat_house.html
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Jackie, the Austin bat colony of 1,500,000 that you saw is said to rise from their roost in the bridge counterclockwise. And so says this from the National Park Service...
"Hundreds of thousands of Mexican free-tailed bats, whirling counterclockwise, spill forth from a gigantic hole in the earth and are silhouetted against a colorful desert sky ... this is the bat flight experience at Carlsbad Caverns National Park."
And faldage, yes the coriolis effect is small on small sized structures but it tugs with unrelenting persistence. Animals that fly especially need every economy of energy that they can get.
By-the-way, in the morning after the night of feeding, the northern hemisphere bats fly back home, but they don't screw themselves (clockwise) back into the cave, instead they dive in a straight line to the mouth of the cave and on to their roost.
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Animals that fly especially need every economy of energy that they can get.
The point is that other forces swamp the Coriolis forces. It's not that it isn't there or that the samll animals can afford to ignore it; it's the fact that other things are more important at that scale.
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Dear Milo: I have looked at a lot of the sites. I finally saw a picture of the narrow gaps between
the concrete blocks that make spaces the bats can use in large numbers. I wondered how it
could be possible for the narrow range of temperatures the bats need.
One thing: I wonder how far the bats have to fly for all of them to find enough insects. It must
be quite a distance, covering a very large area.
Dear Milo: I have a new theory for you. One of the sites said the bats are classified as primates.
Is is possible that like humans they are right "handed", and have the right wing slightly more powerful
than the left, which would tend to make them circle to the left, counterclockwise? (taking my tongue
out of my cheek.) i'm sure Faldage will agree with me that is more probable than the Coriolis force.
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anti-clockwise here, although the main clock in my house runs in the direction traditoinally called anti-clockwise.That's because you guys Upunder dwell in counter-matter! 
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Well, milum, you could always look at it this way...no matter which direction the bats fly in...guano is still guano!
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Here's an elementary bat quiz that none of us here would have any problem in scoring 100% on. The quiz is set up so that you can pretty much tell the answer without knowing it, but you might have a child somewhere who'd like to take the quiz. Do not go to this site if you're not curious about elementary bat quizzes! http://www.cccoe.k12.ca.us/bats/quiz.html
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hat is more probable than the Coriolis force.
Not if I have to accept the notion that they are primates to do it. What's the site, Dr Bill?
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Dear FakdageL I'll have a hell of a time finding that site again. It said they were primates
on the basis of having mammary glands located in the pectoral area. I too wondered why
that was enough to relate them to us.
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Here ;is a site about fling fox, fruit bats, saying they meet criteria to be called primates.
[urk]www.batcon.org/batsmag/v3n2-1.html[/url]
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Coriolis force.
So which way does a baseball rotate when it hits and leaves the bat? Does it rotate differently in each hemisphere?
And what about other batted (cricket) and thrown objects...does the Coriolus affect them in any way, or is it simply the centrifugal spin of contact? I know the spin of thrown objects is almost wholly influenced by the style of release, but are there any hemispheric factors at work in this?
And what about a boomerang...will it come back in an oppsite arc in the Northern hemisphere?
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Well, damn! Bats are primates, according to the OED, wihch lists primates as the highest order of the Mammalia, including man, monkeys, lemurs, and in the Linnaean order, bats.
Now there is a trivia question that deserves to be on Jeopardy.
TEd
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Bats are Primates.
Thats it. I've had it. Next thing you know we'll be closing caves to protect the homes of our distant cousins the bat.
Wait a minute. We already are. Five of the caves that I used to visit in Alabama have been closed to humans for the sake of our little precious guano making idiot cousin the bat.
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>Five of the caves that I used to visit in Alabama have been closed to humans for the sake of our little precious guano making idiot cousin the bat.
Well, if you're upset that you've been denied further permission to play in your relatives' homes, why not invite them to come play in yours? Turnabout is fair play, is it not?
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And he could make a fortune peddling bat guano.
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Don't let it drive you batty.
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