fd2Oct 21, 2023
Wonder of Science

An owl gliding through a cloud of helium-filled soap bubbles reveals wingtip and tail vortices.

Video credit: Usherwood et al.
Source: https://journals.biologists.com/jeb/article/223/3/jeb214809/223686/High-aerodynamic-lift-from-the-tail-reduces-drag

High aerodynamic lift from the tail reduces drag in gliding raptors

Summary: Aerodynamic lift from gliding hawk and owl tails, revealed by tracking helium bubbles, is inconsistent with passive stability or minimizing induced drag, but indicates a role in reducing viscous drag.

The Company of Biologists
Oct 20, 2023 at 11:52pmWeb
Show threadBret MogilefskyOct 21, 2023
@wonderofscience DEATH ON SILENT WINGS
Show threadPatriotic CatsOct 21, 2023
@wonderofscience so that’s how galaxies are made
Show threadVoltaireOct 21, 2023
@wonderofscience okay sure the owl is cool but WHAT!! You can fill soap with helium???? That’s so freaking cool!!!!!
Show threadsmells of bikesDec 29, 2023
@2du @wonderofscience I'm not advising this but you can fill soap with methane and have all sorts of excitement. Or hydrogen, for that matter.
Show threadPeteOct 21, 2023

@wonderofscience

Vortices always come in pairs because the total curl in the fluid has to add up to zero.

Show threadSamuRaiDec 17, 2023
@pete @wonderofscience nieve question. Can they come in a triplet with two having half the curl and opposite of the third maintaining the zero sum?
Show threadPeteDec 17, 2023

@samurai @wonderofscience

Short answer: Maybe
Longer answer: I don’t know
Long answer: It’s complicated

Show threadSamuRaiDec 18, 2023
@pete @wonderofscience as an economist, when I think about something “simple” like fluid dynamics, and how quickly it gets complicated, it amazes me that we know anything about economics at all.
Show threadPeteDec 18, 2023
@samurai @wonderofscience my fluids lecturer said he would go and watch jumbo jets taking off at the airport and exclaimed in a bemused but very posh public school accent that he didn’t “know how the bloody things got off the ground”
Show threadSamuRaiDec 18, 2023
@pete @wonderofscience as I couldn’t settle on a singular reply, I offer a Choose Your Own Adventure::
If you choose “My uncle was a pilot and he didn’t know either. Thankfully, he knew how they landed.” turn to page 57.
If you choose “That’s understandable when you assume a spherical plane.” turn to page 33.
Show threadMama InuOct 21, 2023
@wonderofscience 😮 That is so cool.
Show threadCavedale RhônesOct 21, 2023
@wonderofscience Now we all want to know how to make helium filled soap bubbles. 🤣
Show threadKen CarlsonOct 21, 2023
@wonderofscience Mesmerizing!
Show threadDevil Doll, Esq.Oct 21, 2023

@wonderofscience I am a raptor fan, and an owl lover.

This video is beautiful.

Reminds me of this:

The sound of silence:

https://www.youtube.com/watch?v=d_FEaFgJyfA

(edit: wrong video) 🤦‍♂️

Experiment! How Does An Owl Fly So Silently? | Super Powered Owls | BBC

YouTube
Show threadjesterchen42Dec 17, 2023
@putnamca @wonderofscience Just beautiful. Thanks for sharing!
Show threadDevil Doll, Esq.Dec 17, 2023

@jesterchen @wonderofscience

Isn't it one of the most mind-blowing things you've ever seen?

If you know anything about the physics of sound, it is almost unrealistic.

Owls are very nearly perfection in nature.

Show threadjesterchen42Dec 17, 2023

@putnamca actually... I knew quite a bit... majored in fluid dynamics, minored in technical acoustics... years ago. (Sorry, don't want to brag, just put it into perspective.)

This is just beautiful. As you said: mind-blowing. Stunning. Another reason to be very, very scared if it's quiet in the dark. :)

Show threadDevil Doll, Esq.Dec 17, 2023

@jesterchen

Brag away - very impressive.

My knowledge came from 10 years of hunting submarines for the U.S. Navy.

The efficiency represented here is insane.

Were I a submarine designer, or an aircraft designer, I would be obsessed with achieving this level of efficiency.

The owl proves that it doesn't break the laws of physics, and that's what blows my mind.

Show threadjesterchen42Dec 17, 2023

@putnamca But... if you achieved this level, perfected aircrafts and submarines to be perfectly silent... wouldn't that make your job... well... obsolete? 🤭

I believed for years that designs of cars were perfected a long time ago. Then I had a closer look. Then I wouldn't believe my eyes. At least with electric cars they started optimising stuff there (e.g. rims). I always had this one question:

Why don't they stride for their design being perfect? (Yeah, I know: designers...)

Show threadjesterchen42Dec 17, 2023
@putnamca It's good to hear, there are other people like me out there in the world. :)
Show threadDevil Doll, Esq.Dec 17, 2023

@jesterchen

Again, efficiency. It's ironic, but every job a human might have is to obsolete themselves out of that job.

Work should represent a problem, to be solved.

Once it is solved, then that work would no longer be required.

This is one of my best arguments for UBI, in America. It's the only way to advance, without the inefficiency of a market system.

Yes, I am an engineer. 😉

Show thread@pineywoozle ‘s #3WordNoteDec 29, 2023
@putnamca Well, my only experience comes from sitting and watching my engineering boyfriend run fluid tests, but, I’m also a self employed artist and I know why they don’t strive for functional perfection. It’s not the designers…it’s the customers. Function has never been as salable as form.
Show threadHumble Fan of Atty. WooOct 21, 2023

@wonderofscience

very cool indeed.

Show threadJanGebauerOct 21, 2023
@wonderofscience fascinating. Owl are just the best! 👍
Show threadIαn has moved accountOct 21, 2023
@wonderofscience
I too put up helium bubbles, but still the owls get in!
Show threadSal De GustoOct 21, 2023
@wonderofscience “…reveals wingtip and tail vortices…” and also makes the owl sound hilarious at kids’ parties.
Show threadMaksiSanctum has movedOct 21, 2023
@wonderofscience Neat!
Show threadSeth 🎙️Oct 21, 2023
@wonderofscience Okay that's really cool
Show threadEve, Go Listen to Dead Channel SkyOct 21, 2023
@wonderofscience Owl: Why the air feel like that?
Show threadLucas Janin 🇨🇦🇫🇷Oct 22, 2023
@wonderofscience @tvaziri Fantastic reference! Planes create the same vortex motion. I discovered this during the supervision of a recent project #vfx https://youtu.be/dfY5ZQDzC5s?t=154
Planes clouds and vortices

YouTube
Show threaddxzdbOct 23, 2023
@wonderofscience @adamwulf Makes me wonder what it would look like if I walked through a cloud of helium-filled soap bubble.
Show threadThalassOct 24, 2023
@wonderofscience
Show threadFlo TiNov 19, 2023
@wonderofscience Owl must feel like a badass looking back at the video.
Show threadLynn GrantNov 20, 2023
@wonderofscience Very cool solution. This seems much more pleasant for the owl than having it fly through a smoke tunnel.
Show threadRon JeffriesDec 2, 2023
@wonderofscience
Lovely
Show threadSasha AkhaviDec 2, 2023
@wonderofscience Also probably makes the owl talk all squeaky
Show threadThe_Turtle_MovesDec 3, 2023
@wonderofscience there's gotta be easier ways to wash your owl
Show threadbupigDec 17, 2023
@wonderofscience The. Owls. Are. Not. What. They. Seem.
Show threadIncident Creator ❎Dec 17, 2023

@wonderofscience A fizzual representation.

Sorry.

Show threadMattDec 29, 2023
@wonderofscience Helium filled soap bubbles? Now I want to hear how silly the owl's voice sounds!