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18 Jun 07 - 05:29 PM (#2080314) Subject: BS: The Most Perplexing From: John Hardly The most perplexing phenomenon I've seen. A few weeks ago we had steady 20-25 mph winds with gusts up to 40-50. While the wind was blowing this hard, I witnessed a tiger swallow-tail butterfly holding it's groun...er...wind and hovering quite well against it. How? I'm really curious about the physics of flight that would allow such a phenomenon. I've sailed a bit and understand tacking (sort of) into the wind. This can't be anything like that. How can something that is virtually a two pieces of folded tissue paper with a lightweight worm in the middle fly against a 25 mph wind? |
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18 Jun 07 - 05:33 PM (#2080316) Subject: RE: BS: The Most Perplexing From: Peace Perhaps he ain't flying. Maybe just gliding. Adjusting his wings to a minimum of drag and lift to keep him stationary. Hawks can do that, too. |
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18 Jun 07 - 06:58 PM (#2080407) Subject: RE: BS: The Most Perplexing From: McGrath of Harlow Many a time I've seen birds in a high wind being blown backwards. Maybe they just haven't mastered the trick. |
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18 Jun 07 - 07:21 PM (#2080437) Subject: RE: BS: The Most Perplexing From: heric of course I can only google it but here is an article: Abstract: The images show that free-flying butterflies use a variety of unconventional aerodynamic mechanisms to generate force: wake capture, two different types of leading edge vortex, active and inactive upstrokes, in addition to the use of rotational mechanisms and the Weis-Fogh 'clap-and-fling' mechanism. Free flying butterflies often used different aerodynamic mechanisms in successive strokes. There seems to be no one 'key' to insect flight, instead insects rely on a wide array of aerodynamic mechanisms to take off, manoeuvre, maintain steady flight, and for landing. download at http://users.ox.ac.uk/~zool0206/flow.html Note, also: The Hawkmoths (family Sphingidae), which can fly up to 30 mph (50 kph). The speed varies among butterfly species (the poisonous varieties are slower than non-poisonous varieties). The fastest butterflies (some skippers) can fly at about 30 mile per hour or faster. Slow flying butterflies fly about 5 mph. |
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18 Jun 07 - 07:23 PM (#2080439) Subject: RE: BS: The Most Perplexing From: Peace They just ARE, man. They have become one with the breeze. |
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18 Jun 07 - 07:28 PM (#2080445) Subject: RE: BS: The Most Perplexing From: bobad Them are buddhaflies. |
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18 Jun 07 - 08:49 PM (#2080533) Subject: RE: BS: The Most Perplexing From: Amos That 'bout says it all, bobad!! Be one with the wind.... A |
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18 Jun 07 - 08:50 PM (#2080536) Subject: RE: BS: The Most Perplexing From: Peace Kumbaya my Lord, kumbaya Kumbaya my Lord, kumbaya Kumbaya my Lord, kumbaya Oh Lord, kumbaya Someone's singing Lord, kumbaya Someone's singing Lord, kumbaya Someone's singing Lord, kumbaya Oh Lord, kumbayah Someone's laughing, Lord, kumbaya Someone's laughing, Lord, kumbaya Someone's laughing, Lord, kumbaya Oh Lord, kumbaya Someone's crying, Lord, kumbaya Someone's crying, Lord, kumbaya Someone's crying, Lord, kumbaya Oh Lord, kumbaya Someone's praying, Lord, kumbaya Someone's praying, Lord, kumbaya Someone's praying, Lord, kumbaya Oh Lord, kumbaya Someone's sleeping, Lord, kumbaya Someone's sleeping, Lord, kumbaya Someone's sleeping, Lord, kumbaya Oh Lord, kumbaya Oh Lord, kumbaya |
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18 Jun 07 - 09:28 PM (#2080587) Subject: RE: BS: The Most Perplexing From: John Hardly Someone's flying, Lord, kumbaya Against the wind, Lord, kumbaya Butterflies are like tissue, Lord, kumbaya Oh Lord, how'd they do it? Oh Lord, how'd they do it? I can believe the butterflies can fly (unlike bumblebees -- which everyone into aviation knows, cannot possibly fly). The reason it seems feasible that butterflies can fly is that they seem like two sheets of paper and very light -- like it'd take almost nothing to keep them aloft. Like, if you drop a piece of paper from an airplane you don't expect that the paper is going to stay edge-side down and plummet to earth like a razor slicing deeply into the earth, or whatever got in its way -- like a person's upturned head -- A person who just happened to have that sensation of something above them falling and they either look up or duck -- depending on what their spidey-sense is telling them to do. But if it was a piece of paper, I'd volunteer to stand under it. Even if it had fallen from 10,000 feet above (maybe a careless airline passenger dropped a piece of paper out their window because the airline stewardess forgot to tell everyone NOT to roll down their windows at 10,000 feet). But I'd throw all caution to the wind -- even that 25 mile an hour wind that the butterfly seemed capable of defying -- and stand underneath that paper and even let it hit me in the head. I don't think it would hurt me. Sure, I could get a paper cut. Big whup. And if I dropped a butterfly from a plane at 10,000 feet, I bet that it would fall to earth about like that piece of paper. Even if it was dead before it was dropped from an airplane. It would not fall like Les Nessman's turkeys. And I still can't see how a butterfly can hold it's position in a 25 mile an hour wind. Butterflies are all surface and no engine. |
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18 Jun 07 - 09:38 PM (#2080599) Subject: RE: BS: The Most Perplexing From: Peace "Q22: How do butterflies fly? A22: Butterflies have strong muscles in their thorax which force their wings up and down on a fulcrum basis. They actually go in a slanted figure 8 motion that propels them forward through the air in the same principle as an airplane." |
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18 Jun 07 - 09:46 PM (#2080615) Subject: RE: BS: The Most Perplexing From: Stilly River Sage Sure, I could get a paper cut. Big whup. I've had a couple of paper cuts that might make you think differently about that. Obviously, John, those butterflies are actually flying 25mph. Into the wind. It averages out to a stationary attitude as far as the space they occupy when they do it. SRS |
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18 Jun 07 - 10:23 PM (#2080658) Subject: RE: BS: The Most Perplexing From: Sorcha Or, they can angle their bodies perfectly into the wind and exert no energy at all while remaining stationary. They have 2 pr of wings. Get them both just at the right angles...seems reasonable to me. Sit there and 'float' on the wind. What colour is the wind? |
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18 Jun 07 - 11:01 PM (#2080673) Subject: RE: BS: The Most Perplexing From: Amos One at an angle to drive a dive, and the other at an angle to drive a climb, would conceivably use the wnd's force to fight the window. They be jujitsu-flys. A |
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19 Jun 07 - 03:38 AM (#2080765) Subject: RE: BS: The Most Perplexing From: Liz the Squeak What colour is the wind? Burple. Butterflies can do that because they think they can. Try telling one it can't and it'll ignore you. Have you never seen someone do something and thought 'I can do that' without having experienced the action? LTS |
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19 Jun 07 - 06:08 AM (#2080836) Subject: RE: BS: The Most Perplexing From: John Hardly "Butterflies can do that because they think they can" Yeah, butterflies are big fans of Norman Vincent Peale and Anthony Robbins. Maybe they strived to learn to fly -- even against the wind -- because they couldn't abide the thought of being called "butterwalkers". |
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19 Jun 07 - 06:45 AM (#2080862) Subject: RE: BS: The Most Perplexing From: Grab Was the swallowtail flapping, or just hovering with wings steady? If the former, I'd be surprised. The wings have to go across the wind to flap, so that'd be hard to flap fast enough. But if it angles its wings into the wind, a butterfly has hardly any cross-sectional area, so its weight and the small aerodynamic force is likely enough to keep it in place. Birds have a pretty big cross-sectional area, especially larger birds with more aerofoil-shaped wings that can glide efficiently. Seagulls often get blown back by the wind because of that. But sparrows rarely do - as small birds, flapping works better than gliding (because gliding makes you a sitting target for a hawk), which means they have small wings and an already-small cross-sectional area. Graham. |
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19 Jun 07 - 11:42 AM (#2081140) Subject: RE: BS: The Most Perplexing From: Stilly River Sage Unless, of course, you take into consideration the immature hawk that was sitting atop my bird feeder hoping the sparrows would flap up to him. For some reason they didn't, they remained motionless under the cover of the adjacent rosemary shrub. Wind conditions were mild. SRS |
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19 Jun 07 - 12:16 PM (#2081172) Subject: RE: BS: The Most Perplexing From: Amos JH: LOL!!! A |
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19 Jun 07 - 01:24 PM (#2081241) Subject: RE: BS: The Most Perplexing From: gnu Flustered by a butterfly that does not flutter by? Don't phase me. |
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19 Jun 07 - 01:29 PM (#2081250) Subject: RE: BS: The Most Perplexing From: John MacKenzie There you go! G |
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19 Jun 07 - 01:48 PM (#2081273) Subject: RE: BS: The Most Perplexing From: Megan L Actually it wasn't a swallow tail at all what you witnessed was the chaos butterfly and the beginings of a fierce but very localised storm centered on a small yurt in the plains of outer Mongolia. ;) |
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20 Jun 07 - 08:50 AM (#2082079) Subject: RE: BS: The Most Perplexing From: EBarnacle I would consider the analogy of a sailboat lying to. It is a matter of setting the sails so that the wind does not move the boat significantly in any direction. If the butterfly sets its wings for minimum drag and minimal lift, it ought to be able to manage with fewer strokes [thus less energy expenditure]. |