English Subtitles for Hummingbird Aerodynamics- High Speed Video - Smarter Every Day 27



Subtitles / Closed Captions - English

Hey it's me Destin.

So to fly slow is one of the more difficult things to do because you don't have as much airflow over your control surfaces. To fly at zero air velocity is the hardest thing to do of all. Over the past weekend I've been making observations of hummingbird flight in my back yard. So let's look at my observations and then we'll come back, and we'll look at the science of how hummingbirds fly. You're getting Smarter Every Day.

[music] So what does olive oil and lasers have in common. Hummingbirds obviously. Dr Doug Warrick at Oregon State University and Dr Brett Tobalske at University of Montana have been studying hummingbirds by using a nozzle to spray olive oil

in the air around a hummingbird. And then they'll take a laser and then they'll slice sections of the air where the olive oil is, to measure the flow field. Basically it's called digital particle image velocimetry. What you do is you get a picture of an oil droplet, you wait some finite amount of time later and then you get another picture of an oil droplet. That gives you a two dimensional visualisation of the flow field around a hummingbird, which is awesome.

So what you can do is you can use this information to calculate exactly what the hummingbird is doing to stay aloft. In these pictures you can see here, you can see vortices underneath the wing. Using this technique they discovered that about 70% of the hummingbird's lift comes from the fore stroke, and 30% comes from the back stroke. It's not 50-50 like I used to think it was. Another thing I observed is when a hummingbird would come into the feeder, right before he'd get there

he would make this tail flick. I didn't know what that was so I called Dr Warrick and asked him. Right now Dr Warrick and his team of biomechanists don't really know what this tail flick means. They're not sure if he's changing the airflow around his body or if he's changing his centre of gravity under his wings so that the can make a maneuver that way. What they are doing however is making a six degree of freedom model so that they can study this further. If you want to learn more about it check out the links in the video

description. So a lot of you have been asking about what kind of camera I've been using. It's a Phantom made by Vision Research. If you want more info on it go to the description, I'll put a link there for you so you can go to the website. Other than that click the bird feeder here, and uh.. You can subscribe. Oh.. Just subscribe by clicking

the link below, and I hope you're getting Smarter Every Day. [cough] That is... That's some good stuff. [music]

[ Captions by Andrew Jackson ] captionsbyandrew.wordpress.com Captioning in different languages welcome. Please contact Destin if you can help.



Video Description

I'm shooting with a Phantom V10 camera made by Vision Research.
http://www.visionresearch.com/Contact-Us/Contact-Form/ - Click here and tell them Destin sent you! That will be fun.
http://www.visionresearch.com/ - Click for high speed video awesomness

Musical genius Gordon McGladdery made the music! Download it here: http://ashellinthepit.bandcamp.com/track/its-probably-gonna-be-ok

Click here to see Dr. Warrick and Dr. Tobalske's paper:
http://dbs.umt.edu/flightlab/documents/Warrick_Tobalske_Powers_2005_Nature.pdf - click to see a paper by Dr. Warrick and Dr. Tobalske.


Check out our Facebook Page! We post photos and behind the scenes stuff.
http://on.fb.me/SED-Facebook

A special thanks to Wayne for offering to help me edit while I tried to make it through my Thesis Defense this week. I did not ask and he offered. Thank you Wayne.

Dr. Warrick provided the following papers for additional research.

Tyson L. Hedrick
Damping in flapping flight and its implications for manoeuvring, scaling and evolution J Exp Biol 2011 214:4073-4081. doi:10.1242/jeb.047001

and

Hedrick, T. L., Cheng, B. and Deng, X. (2009).
Wingbeat time and the scaling of passive, rotational damping in flapping flight. Science 324, 252-255.

One of our papers is accessible to all from the journal: http://rspb.royalsocietypublishing.org/content/276/1674/3747.full.pdf+html?sid=ace21399-b4fa-44be-b245-bd320c662bac

Instead of saving for my kids' college, I make videos using the money I would have saved.
The thought is it will help educate the world as a whole, and one day generate enough revenue to pay for their education. Until then if you appreciate what you've learned in this video and the effort that went in to it, please share the video. If you REALLY liked it, feel free to pitch a few dollars towards their college fund by clicking here:
http://bit.ly/KidsCollege

Warm Regards,

Destin

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