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Airspeed Velocity Of An Unladen Swallow
An anonymous reader writes "Finally, the question is answered: What is the airspeed velocity of an unladen swallow? A designer with too much time on his hands uses his new method for graphically representing Strouhal numbers to clarify a truly pressing question for all armchair zoologists (and a few Monty Python fans)."
I hate to say it, but this is one of those things like the explanation of where the immortals in Highlander came from -- we didn't actually want to know.
dmiessler.com -- grep understanding knowledge
NONE! ... Shall pass...
.: Max Romantschuk
A 54-year survey of 26,285 European Swallows captured and released by the Avian Demography Unit of the University of Capetown finds that the average adult European swallow has a wing length of 12.2 cm and a body mass of 20.3 grams.
54 years? That's amazing, i think I could copy that research with a shotgun, a measuring tool and a free sunday afternoon.
... looks like someone's pushing for recognition :-)
Simon
Physicists get Hadrons!
Yes, finally someone had the balls to answer this question that has been wracking the minds of scientists for ages!
Someone get this man a nobel.
just so you know
While the intentions are good, the only truly elegant answers for a question like this would be a related to "42" While a laden swallow would most likely be "69" - one can only guess how it would be unladen
European actually, and the airspeed velocity of an unladen European Swallow is roughly 11 meters per second, or 24 miles an hour.
Verdict is still out on African(but is probably about the same). The eternal question still stands.
The key to the enjoyment of pop music is to replace any instance of "love" with "C.H.U.D."
In reality they have to bid and win for the money to do such things, against stiff competition. Just think of the talent, skill and dedication that went into convincing a biscuit manufacturer to fund such research. Can you imagine standing up in front of a review board and pitching that? The man's a genius.
I'm guessing that this swallow work was a personal project, but this also was a work of genius. After all, most of their research will go into a dry and dusty journal. Nobody will read it, nobody will notice. However this will be quoted for as long as some smartarse quotes Monty Python. The publicity and the (indirect) fame is well worth the small effort involved.
Getting your name known, and getting contacts and work as a result, is as much a part of science today as actually discovering new knowledge. This is just marketing, but without the dodgy haircuts and inflated salaries.
The relevant pieces in the script :
A swallow carrying a coconut? and The Bridge of Death
siener's youtube channel
To imply similarity, make the graph larger than it needs to be. Then all of your points will fall in a narrow range and appear closer together.
For this and other presentation crocks, read How to Lie with Charts, and its fore-runners, How to Lie with Statistics and How to Lie with Maps.
But what is your favourite colour?
Blue
Everything in the world is controlled by a small, evil group to which, unfortunately, no one you know belongs.
For his next article, can he tell us if the parrot is dead?
Now that we finally know the right question to match the ultimate answer, I suppose the universe can end.
;-)
Somehow it does not surprise me that Douglas Adams and the Monty Python crew are the secret masters of the universe.
"They that can give up essential liberty to obtain a little temporary safety deserve neither liberty nor safety."
Sorry, but English modals follow the same pattern for negation:
....l
Will, will not.
Would, would not.
Do, do not.
May, may not.
Must, must not.
Can, can not.
Sure, 'cannot' is a (more) acceptable alternative spelling for that particular case, but not the only acceptable one.
see:
http://www.bartleby.com/68/4/1104.html
http://www.wsu.edu:8080/~brians/errors/cannot.htm
Very good.
In other words, in airscrew terms, the effective pitch of the blade* rpm is a very linear function of speed.
Everyone who did physics at school will know that the optimum speed for a momentum transfer device (eg a waterwheel) is a very simple ratio of the stream velocity.
Damn, I thought it was a pretty neat article, now you tell me it is a (very pretty) statement of the bleeding obvious.
I find your ideas intriguing and I wish to subscribe to your newsletter.
You have saved us all!
This is so cool. Now, the next time we put Holy Grail in the DVD player, I can watch the scene and be like,
"Actually, that's not correct."
If there were any chicks at these MP parties, I am sure it would go over well.
dmiessler.com -- grep understanding knowledge
Perhaps you are able to sit in your chair at home and, using purely a priori reasoning, arrive at conclusions that others must use empirical investigation to achieve. And perhaps, once the scientists have arrived at those answers through painstaking quantitative research (as in the case of the authors of the Nature article), you enjoy pointing out that you reasoned your way there without the messiness of actual research. Fair enough.
But even if the discovery made wasn't surprising to you, it was interesting enough to make it into Nature. And the author of the style.org article on Strouhal numbers was clearly concerned not so much with the discovery as with the graphical representation of the information discovered. He is, after all, a designer.
In other words, you may benefit from spending a little more time trying to figure out what people are doing, and a little less time trying to show everyone how far ahead of them you are.
11 m/s is approximately 21 knots. So the combined airspeed of two European swallows is... (drumroll) 42 knots.
The site has now been mirrored by karma whores on numerous different hosts at great expense and at the last minute.
"Look my liege! Charts describing Strouhal numbers and swallows!"' s only a model."
*trumpets*
"Charts!"
"Charts!"
"It
"Shhh!"
Small potatoes make the steak look bigger.
You might be able to calculate the speed of a swallow, but the velocity is something different.
Might as well go completely off-topic on a story like this.
:-)
The bonus question was, what's the capital of Assyria? One of the answers was Nineveh, which in the Bible is where God sent Jonah to warn the city's inhabitants of their impending destruction unless they repented of their evil ways. Jonah, who hated the Assyrians and didn't want Nineveh to have a chance to escape destruction, fled to Spain instead (about as far away as he could get), hoping God wouldn't be able to find him there. That obviously didn't work; Jonah was swallowed by a giant fish in the middle of the Mediterranean, then spit out whole; after sulking for awhile he did make the trip to Nineveh, told the people they were being wicked in the eyes of God, and to his dismay, they repented and changed their ways.
So my question to any Slashdotters who happen to be history geeks: is there a non-Biblical historical record of any such change in the attitude or behavior of the people of Nineveh ( or the Assyrian Empire in general) that would coincide with the story about a warning of doom from an Israeli prophet? Biblical stories are always so much more interesting in proper historical context, and I know nothing about the subject, and this isn't an appropriate place to ask, but what the hell, I've got more karma than I know what to do with anyway.
$x='S24;r)>63/* h@<5+oZ)32"5cz';$me='phroggy'x$];
$x=~y+ -xz+\0-Tx+;print$_^chop$me for split'',$x;
GUARD #1: Where'd you get the coconut?
ARTHUR: We found them.
GUARD #1: Found them? In Mercea? The coconut's tropical!
ARTHUR: What do you mean?
GUARD #1: Well, this is a temperate zone.
ARTHUR: The swallow may fly south with the sun or the house martin or the plumber may seek warmer climes in winter yet these are not strangers to our land.
GUARD #1: Are you suggesting coconuts are migratory?
ARTHUR: Not at all, they could be carried.
GUARD #1: What -- a swallow carrying a coconut?
ARTHUR: It could grip it by the husk!
GUARD #1: It's not a question of where he grips it! It's a simple question of weight ratios! A five ounce bird could not carry a 1 pound coconut.
ARTHUR: Well, it doesn't matter. Will you go and tell your master that Arthur from the Court of Camelot is here.
GUARD #1: Listen, in order to maintain air-speed velocity, a swallow needs to beat its wings 43 times every second, right?
ARTHUR: Please!
GUARD #1: Am I right?
ARTHUR: I'm not interested!
GUARD #2: It could be carried by an African swallow!
GUARD #1: Oh, yeah, an African swallow maybe, but not a European swallow, that's my point.
GUARD #2: Oh, yeah, I agree with that...
ARTHUR: Will you ask your master if he wants to join my court at Camelot?!
GUARD #1: But then of course African swallows are not migratory.
GUARD #2: Oh, yeah...
GUARD #1: So they couldn't bring a coconut back anyway...
GUARD #2: Wait a minute -- supposing two swallows carried it together?
GUARD #1: No, they'd have to have it on a line.
GUARD #2: Well, simple! They'd just use a standard creeper!
GUARD #1: What, held under the dorsal guiding feathers?
GUARD #2: Well, why not?
www.slightlycrewed.com - Because aren't we all?
A) you can divide the distance traveled by the swallow by the time it took to travel that distance, or
B) you can use a radar gun to measure speed directly
(Especially when, if you read the article, there is mention that "wind tunnel tests" of swallows showed that their estimates were off (espeically on beat frequency). And they actually used speed measurements to validate their model. Hrm. Seems like an awful lot of work to me...)
My apologies. I'm a bit cynical this morning.
"There are a dozen opinions on a matter until you know the truth. Then there is only one." - CS Lewis (paraprhase)
To those who got modded +1 Informative:
NI!!!!
(damn you people, you're killing the moment!!!)
// file: mice.h
#include "frickin_lasers.h"
The thing that always bugged me about this scene in the movie is the term, "air-speed velocity". Isn't that kind of redundant?
Then again, I'm the kind who yells at the Scarecrow in the Wizard of Oz whenever he tells us
"The sum of the square roots of any two sides of an isosceles triangle is equal to the square root of the remaining side."
JoAnn
The parent post does a great job of explaining why the Strouhal Number is the same across a range of organisms that use flapping for propulsion. Yet a glance at the graph shows considerable variation among creatures -- a 3:1 range between leaf-nosed bats and gulls. Most of the soaring air-based animals have Strouhal's of around 0.2, whereas the water-based animals have Strouhal's of around 0.3.
It would be interesting to understand not why Strouhal Numbers are constant, but why they vary. I would assume that wing (or fin) shape would affect the optimal Strouhal Number because the Number is calculated on the wing tip, whereas the optimal flap is based on integrating over the wing surface. Wings of different designs, articulations, and flap movement trajectories would have different ratios between the tip-amplitude and the average area-weighted amplitude across the wing surface. I would expect that area-weighted Strouhals to have even less variation across animals that the tip-based number.
Other factors might explain remaining variation. For example, sinusoidal wing beats would have a different Strouhals than square-wave wing beats. Perhaps the Reynolds number might affect Strouhals - explaining the difference between "flight " in air vs. water. Finally, some animals that only fly short distances may have sub-optimal Strouhals because the wings are optimized for other purposes such as courtship.
Two wrongs don't make a right, but three lefts do.
You mean, kind of like the pigeon cluster google has?
Probably you would be run over and beaten afterwards by people who would complain, that the switch doesn't work. If the switch worked, they would complain too (about lax security measures) if they still could.
Bye, Martin
How can sheep's bladders be used to prevent earthquakes?
Just consider the facts:
B: What causes earthquakes?
A: Sudden slippage along a fault line
B: Ah, but WHY does that cause earthquakes?
A: Because it's a lot of ground moving?
B: No, try again.
A: Because it doesn't slip smoothly?
B: Yes, that's right. So...logically...
A: We could prevent it if we got it to slip smoothly?
B: And what do you slip on all of the time?
A: Sheep urine?
B: Absolutely. And where do you find sheep urine?
A: Sheep bladders.
B: Therefore...
A: If we stick sheep bladders into a fault line, it'll prevent earthquakes!
A: Thank you, Bedevere. Good insight.
B: My pleasure, Oh King.
Mod me down and I will become more powerful than you can possibly imagine!
Now if only someone explain how to chop down the largest tree in the forest using only a HERRING!
Jory
Probably you would be run over and beaten afterwards by people who would complain, that the switch doesn't work. If the switch worked, they would complain too (about lax security measures) if they still could
/me ducks.
So, you mean you'd hear complaints from slashdotters?