[HN Gopher] Goose flying upside down is simply showing off, say ...
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Goose flying upside down is simply showing off, say experts
Author : MaysonL
Score : 107 points
Date : 2021-08-02 07:51 UTC (1 days ago)
(HTM) web link (wgme.com)
(TXT) w3m dump (wgme.com)
| datavirtue wrote:
| "Once young geese have mastered flying, they start to see what is
| possible and how far they can go, pulling in random JavaScript
| libraries and changing the testing framework for no reason."
| ProAm wrote:
| This usually results in a flat spin and death heading out to sea.
| dylan604 wrote:
| Talk to me Goose!
| projectramo wrote:
| Sigh. That was Maverick in the (we prefer the term) inverted
| dive. Goose was just along for the ride.
| dylan604 wrote:
| coughbullshitcough
| djrogers wrote:
| Communicating. Keeping up foreign relations. I was, uh, you
| know, giving him "the bird."
| blunte wrote:
| I saw this exact thing a couple of months ago not so far from
| Arhnem. (I thought it might be a crane, but it was moving very
| fast... so I could be mistaken.)
|
| This bird was diving at about 30-45 degrees from fairly high, and
| it suddenly inverted, stayed inverted for a second or so, and
| then righted itself. It was moving very fast, and you could
| actually hear the sound (and the changes of sound) of the air as
| it was moving through it.
|
| There were no other airborne birds of that size that I could see
| anywhere near it, so I initially thought it was dying or
| otherwise out of control. But then it descended below view, and I
| never heard a thump.
|
| I searched for inverted bird flight immediately after and learned
| that there are a number of observed cases where birds may do
| that. One theory is that they sometimes do it because they enjoy
| it. Other theories of course involve chasing prey, observing
| things, showing off, etc. But I like the idea that a bird might
| just be having fun. I mean, if I could fly, I think I would screw
| around all the time just because I could. After all, children
| will just run around wildly just because they can run.
| brundolf wrote:
| We often assume non-human animals are totally focused on the
| logical business of survival. But we aren't, and I don't see
| why they would be any different
| jon_richards wrote:
| Here's a fun example
| https://www.youtube.com/watch?v=EGaSHDmuAPg
| cupcake-unicorn wrote:
| Haha, real /r/nottheonion vibes here :) Would love to see a video
| jkaplowitz wrote:
| I first saw this news on that exact sub. :)
| isoprophlex wrote:
| Very interesting... website is pretty terrible though. Here's a
| link to a translated local source with the same info:
|
| https://www-rtlnieuws-nl.translate.goog/editienl/artikel/524...
| iforgetmypass wrote:
| The original source is some strange indie news wire service
| I've never heard of before, "Zenger news."
| CommonGuy wrote:
| What is this kind of annoying cookie consent dialog? Takes over a
| minute to disable advertisment cookies, probably just to coerce
| users into accepting all cookies
| callesgg wrote:
| Took 20s to just accept them.
| timdaub wrote:
| I closed the page when it popped up. I didn't end up reading
| anything on the site.
| mngnt wrote:
| > This may take up to a few minutes to process.
|
| It did for me. When it got to "applying settings", I scrolled
| down and started reading. Then, as I was half way through, it
| scrolled all the way up just to proudly announce that the
| Sisyphean task of NOT tracking me is done.
|
| > You have successfully updated your Cookie settings.
| opheliate wrote:
| At this point, seeing the TrustArc dialogue evokes a visceral
| urge to exit whatever page I'm on ASAP. I can't believe they're
| able to get away with this kind of behaviour.
| anigbrowl wrote:
| I'd be quite happy if CA sued them. Or you could add up the
| 10-20 second time wasted and multiply it by several million
| californians to get a sense of how many person-years of
| attention they're stealing to try to trick people into
| waiving their privacy rights.
| brink wrote:
| Can we just appreciate the funny article?
| dylan604 wrote:
| Not if you can't get past the cookie window
| herpderperator wrote:
| This is hilarious. It was literally "loading" for a good few
| seconds and then "processing" the request for even longer. What
| in the world...
| Shank wrote:
| This is why I really suggest using uBlock Origin, blocking all
| of the trackers, and then removing the cookie popups. That
| would have been blocked by the "EasyList Cookie" and "Fanboy's
| Annoyances" list(s), with the other default filters in place
| for trackers.
| noduerme wrote:
| >> This aerial acrobatic resembles a falling leaf and may be used
| to avoid avian predators or a long, slow descent over an area
| where hunters for sport or food are present.
|
| Reminds me of a description I heard from a DEA pilot of the
| combat landings they would pull in Colombia.
|
| https://www.businessinsider.com/a-c-130-pilots-view-of-a-com...
| hahamrfunnyguy wrote:
| A Goose flying upside down:
|
| https://www.youtube.com/watch?v=7AeJ3aLm0UY
| ambirex wrote:
| say experts who are flightless and honestly a little jealous ;)
| anonu wrote:
| Trying to find more photos of this phenomenon [1][2]
|
| [1] https://www.nikoncafe.com/threads/wow-canada-goose-flying-
| up... [2]
| https://www.telegraph.co.uk/news/earth/wildlife/5353933/Goos...
| rsync wrote:
| "Because I was inverted."
|
| https://www.youtube.com/watch?v=ump0N5yOpkM
| sorokod wrote:
| Cue the conversation on how wing works.
| SonicScrub wrote:
| One of my favourite pointless internet arguments! I usually
| just point to this link and walk away:
|
| https://www.scientificamerican.com/article/no-one-can-explai...
|
| Answer: because a surface of a certain geometry produces a
| force perpendicular to fluid flow as per the Navier-Stokes
| equations. But that's not a good explanation to give a room
| full 2nd graders, therefore your pet-explanation will have to
| make a compromise somewhere. You are all equally right and
| wrong at the same time. Unless you say "equal transit theory".
| Then you are just wrong.
| nas wrote:
| That sounds like the problem of explaining how magnetism
| works. Engineers and scientists understand very well how
| airfoils generate lift. It is not some kind of mystery like
| the article implies.
|
| It is true that most of the popular simplified explanations
| are incorrect. Flat plate airfoils generate lift if they have
| positive angles of attack. Airplanes can fly upside down. At
| fractional mach numbers, pressure above and below the wings
| is essentially equal.
|
| If you are not flying near the speed of light, Newton's laws
| apply. So, if you want simple explanation, the wing deflects
| air downwards and that pushes the airplane up. If you put
| your hand outside the car window at an angle, you will feel a
| force. Should be simple enough for 2nd graders.
| [deleted]
| SonicScrub wrote:
| The article doesn't imply it's a mystery, only that simple
| one-liner explanations are insufficient. The headline is
| reasonably clickbait-y.
|
| The momentum theory of lift is simple, intuitive, but
| unfortunately incomplete (just as the differential pressure
| explanation). It's covered in the article.
|
| > But taken by itself, the principle of action and reaction
| also fails to explain the lower pressure atop the wing,
| which exists in that region irrespective of whether the
| airfoil is cambered. It is only when an airplane lands and
| comes to a halt that the region of lower pressure atop the
| wing disappears, returns to ambient pressure, and becomes
| the same at both top and bottom. But as long as a plane is
| flying, that region of lower pressure is an inescapable
| element of aerodynamic lift, and it must be explained.
|
| Also I want to address this:
|
| > At fractional mach numbers, pressure above and below the
| wings is essentially equal.
|
| Surely you mean density? Air pressure is certainly not the
| same above and below, as differential pressure integrated
| over the surface is equal to the lift force generated by
| the wing. So no, while the Newton's explanation is a great
| explanation for a second grade classroom, it is not
| complete.
| nas wrote:
| > Surely you mean density?
|
| The ideal gas law applies, at least nearly enough. So PV
| = nRT. By saying the density is equal between the top and
| bottom, you are also saying the pressure is equal. The
| air around the wing is having it's momentum changed, not
| it's pressure. At least, at sub mach speeds.
| SonicScrub wrote:
| You're confusing static, dynamic and total pressures.
| Static pressure is the pressure of a fluid on a body when
| the body is at rest relative to the fluid. Dynamic
| pressure is the velocity created pressure. Total pressure
| is the sum of the two, and is what is used in the ideal
| gas law. To compute lift force static pressure is what is
| integrated around the wing surface. Total pressure
| remains constant in the fluid flow for low Mach numbers.
| Static pressure can and absolutely does change
| significantly as it accelerates through a streamline such
| as in low-speed aerodynamics.
|
| The following is an image of the pressure distribution of
| a NACA 2412 airfoil at low speeds.
|
| https://www.chegg.com/homework-help/questions-and-
| answers/n-...
|
| In aerodynamics, pressure is usually simplified to a
| Pressure Coefficient (CP) value. A CP of 0 is when static
| pressure equals atmosphere. A CP value of 1 occurs at the
| stagnation point (where velocity is 0, therefore static
| pressure equals total pressure). Note how this type of
| chart has an inverted y-axis (a common convention so that
| the wing upper surface is at the top). Notice how the
| static pressure on the lower surface is roughly
| atmospheric, while the upper surface pressure suction
| peak is roughly equal in magnitude to the dynamic
| pressure. This is a typical pressure distribution for
| most airfoils.
| twic wrote:
| > But taken by itself, the principle of action and
| reaction also fails to explain the lower pressure atop
| the wing
|
| What? The pressure is lower on top of the wing and higher
| below because the air is being pushed downwards by the
| wing. I will happily explain this to any second-grade
| classrooms you find yourself having trouble with.
| SonicScrub wrote:
| And how is that air moving from the upper surface to the
| lower surface of the wing? is it magically permeating the
| wing surface? Keep in mind that the vast majority of the
| pressure differential comes from upper surface suction
| rather than a pressure increase on the lower surface. At
| shallow angles of attack there is often little or no
| increase in pressure on the lower surface; nevertheless
| lift is produced. Your simplification does not adequately
| explain this, as addressed in the section of the article
| subtitled: "Turning on the Reciprocity of Lift"
|
| > Nevertheless, there are at this point only a few
| outstanding matters that require explanation. Lift, as
| you will recall, is the result of the pressure
| differences between the top and bottom parts of an
| airfoil. We already have an acceptable explanation for
| what happens at the bottom part of an airfoil: the
| oncoming air pushes on the wing both vertically
| (producing lift) and horizontally (producing drag). The
| upward push exists in the form of higher pressure below
| the wing, and this higher pressure is a result of simple
| Newtonian action and reaction.
|
| > Things are quite different at the top of the wing,
| however. A region of lower pressure exists there that is
| also part of the aerodynamic lifting force. But if
| neither Bernoulli's principle nor Newton's third law
| explains it, what does? We know from streamlines that the
| air above the wing adheres closely to the downward
| curvature of the airfoil. But why must the parcels of air
| moving across the wing's top surface follow its downward
| curvature? Why can't they separate from it and fly
| straight back?
| WJW wrote:
| The article does specify that "nobody can _explain_ how
| wings work ", not that "nobody _knows_ how wings work ". It
| also tries to go into "but WHY do the Navier-Stokes
| equations work like this", which is just not how physics
| works.
|
| But yeah, there is just not an explanation that is both
| simple and complete and journalists have a pretty rough
| time dealing with that.
| svachalek wrote:
| It seems similar to explaining monads. If you stick to the
| math and logic, it's quite clear and hard to confuse. But if
| you succumb to the common temptation to explain it in a more
| "intuitive" way, it seems you are doomed to tumble down the
| stairs in the dark.
| filoeleven wrote:
| I usually just say "Bernoulli's principle" with a hand-wave.
| It's an ignorant dismissal accompanied by a practical
| demonstration. Works great at parties inside wind tunnels.
| tzs wrote:
| One of the reasons there is so much confusion on this is that
| there are at least two different valid ways to look at it, but
| any given person usually only knows one of them (or rather, a
| simplified version of a serious misunderstanding of one of
| them). Different people know a different one of them, and thus
| argument breaks out whenever the topic comes up.
|
| NASA has a bunch of aerodynamics educational material on their
| old Glenn Research Center website. Here's a page on these two
| different ways to look at lift [1].
|
| Very briefly, the gas flow has to simultaneously conserve mass,
| momentum, and energy.
|
| One approach is to consider conservation of energy. When you
| work out the implications of that you get different flow
| velocity over different parts of the wing and different
| pressure due to those differences. When you integrate the
| pressure over the whole wing you find that you get lift.
|
| The other approach is to consider conservation of momentum.
| Working out the implications of that, you get velocity
| differences in the flow. If you integrate those around the
| whole wing, you find that there is a net turning of the flow
| downward. Conservation of momentum requires that the wing gets
| momentum opposite of that and we have lift.
|
| [1] https://www.grc.nasa.gov/www/k-12/airplane/bernnew.html
| dylan604 wrote:
| >or rather, a simplified version of a serious
| misunderstanding of one of them
|
| or both?
| foolinaround wrote:
| My memory is weird!
|
| As I was reading this link, i suddenly thought of the movie 'Top
| Gun' - which I have'nt watched or discussed this decade!!
|
| And then a few minutes later, it dawned on me!
|
| There is this character called 'Goose'!
| dylan604 wrote:
| If only you'd read the comments thread before posting this...
| throwanem wrote:
| Okay, but the _real_ question here: What 'd he shoot it with?
|
| (Old photographer joke: You're shooting by a lake on a cloudy day
| and you happen on someone drowning, and have to choose between
| dropping your gear to run to the rescue and getting a shot to
| sell the local paper. So - what f-stop do you use?)
| robocat wrote:
| As always, do your refresher: http://spotthedrowningchild.com/
|
| (On iPad I had to stop loading before page would show the
| random video, YMMV).
| dylan604 wrote:
| f/8.
|
| I'd be more concerned about shutter speed. If the drownee is
| flailing their arms, dragging the shutter slower might yield a
| more dramatic look with the motion blur. Too high of shutter
| speed so the action is frozen might look more like someone
| rehearsing their part in a synchronized routine.
|
| Keeping the subject in focus is more important as a decent
| telephoto will get you an out of focus background. Unless
| you're just a dick and use a wide angle but wade out into the
| water to get a decent framing.
| mey wrote:
| And this is why I carry a GoPro around in my bag.
| dylan604 wrote:
| With the lensing of a GoPro, you might as well use a
| CameraPhone. Otherwise, anything further than 20' away will
| only be a few pixels in the GoPro image.
| benjiweber wrote:
| Apparently people drowning don't actually flail their arms
| (never seen anyone drowning though).
| __s wrote:
| There's videos of lifeguards: https://www.youtube.com/watch
| ?v=L0KTqPloUiU&list=PLgqwWmjSsN...
|
| Can be pretty hard to see, but no absolute about flailing
| lmilcin wrote:
| With f/8 on a cloudy day you might get problem getting sharp
| image of the arms or have to settle on grainy image,
| regardless of the lens.
|
| I would use fastest aperture I can that is still sharp and
| just shot a bunch of frames very quickly in hopes I can get
| arms in just the right, dramatic position.
|
| As to whether to shoot wide or tele, if you feel you have
| enough time try to get subject to fill the frame first, while
| he still looks lively, and then quickly change the lens to
| get some additional shots with the background.
| dylan604 wrote:
| dragging the shutter slow enough to get motion blur would
| also make up for any difference in light loss. would
| require some sort of stabilization though. if you don't
| have a tri/monopod, you can set it on the ground and use
| some rocks or sticks (you're near a lake) to prop up the
| lens. also, i'd suggest using a 1 second shutter release
| delay to not have any bounce from you pressing the buttons
| on such a slow shutter.
|
| also, digital cameras could just compensate slower f-stop
| with higher ISO if necessary
| lmilcin wrote:
| > also, digital cameras could just compensate slower
| f-stop with higher ISO if necessary
|
| Actually you can do the same with film. You just push it
| in processing.
|
| Whether film or digital it results in grainy image,
| that's why I actually mentioned it.
|
| Pros don't bring grainy images of drowning people.
| throwanem wrote:
| For film, I'd go with "cloudy 11" and lose a stop or two
| of shutter speed, but I haven't shot film in thirty
| years, so who knows if I'm full of it or not.
|
| (And thank you all for bringing the back half of the joke
| in such inimitable style!)
| dylan604 wrote:
| Only film I ever shot was disposable 35mm and the older
| 110mm. Nothing to be adjusted to get your Cloudy 11 or
| Sunny 16. The one I do use in dslr world is Rule of 500
| for astro stuffs. I'd say now to just ensure shooting RAW
| so you can adjust the white balance in post. Camera
| defaults for cloudy are just too cool to me.
|
| (I'm never one to shy away from answering obvious
| rhetorical questions in a joke)
| mpnordland wrote:
| You're both wrong. There won't be much motion at all
| because drowning people don't splash.
| dylan604 wrote:
| Depends on which stage of drowning they are in. If
| they've just fallen in, they might still be flailing
| away. If they've been flailing for a minute already,
| then, yeah, thy might be tired. Plus, it's hard to shout
| when your lungs are full of water. I can't do it with a
| mouthful of water let alone lungs. My ventriloquist dummy
| on the other hand won't shut up while I'm drinking water.
| iamthepieman wrote:
| someone in the process of drowning, as in exhaustion
| and/or panic causing ineffective motions that do not get
| the head far enough above water to take an adequate
| breath won't be able to splash or yell.
|
| Someone who is not exhausted and not technically drowning
| yet but who will be if left for another 10,15,60 or
| whatever minutes does have the ability to yell and
| splash.
| lmilcin wrote:
| Actually, I am a skipper and because of that I had to go
| through quite thorough training of which large part is
| focused on saving people in Man Over Board situation.
|
| I estimate full 1/3rd of entire training was devoted
| exclusively to getting a person back on the ship if they
| happened to fall into water while underway.
|
| It is said "people do not splash" because if you are
| focused on looking for flailing hands and splashing water
| and shouts for help then your are missing most people
| that drown.
|
| But it doesn't mean people don't shout and don't flail.
| They do. Just not most of the time.
| tintt wrote:
| Geese are cool dudes
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(page generated 2021-08-03 23:00 UTC)