Chickens might seem relatively unremarkable, with their limited flying ability and their regular-sized eggs, but they have at least one cool thing going for them: their awesome auto-stabilising heads! Check out the video below by Destin from Smarter Every Day (and while you’re there, watch every single other video he has made).
So there you go, chickens have inbuilt stabilisation mechanisms to keep their head stationary and improve their visual systems.
Humans work differently though, you’ll find you have to concentrate very hard in order to keep your head still while moving your body around, not to mention your neck doesn’t quite have the same flexibility and stretchy-ness as a chicken’s. So instead, human eyes have a “target-locking” ability. Perhaps you’ve never noticed it before, but if you look at an object and then walk around or move your head, your eyes will naturally remain fixed on the object: your brain is automatically rotating your eyeballs and correcting your focus in real time to keep the object locked.
Try to stop doing it though: look at an object, and try to make your eyes NOT lock onto it. You’ll find it’s almost impossible, although if you intentionally defocus you can get close.
Walking the walk
Many bird species, including chickens and pigeons, bob their heads while they walk. In the context of what we just discussed, perhaps we can now explain why!
Next time you’re out and about, see if you can find a pigeon. If you watch carefully while it walks, you’ll notice its head stays stationary for most of the movement, then jumps forwards quite quickly. This way, the bird can keep its eyes targeted on one thing. It can be difficult for us to spot because our brains naturally lock onto the pigeon so we see its head relative to its body, not the surroundings. If you’re particularly keen, you could record a video of it then analyse it in a bit more detail when you get home.
Experiments in the 70s showed that if you put a pigeon on a treadmill at its natural walking speed, the head bobbing stops. This is because the head will be already stationary with respect to the surroundings, so the bobbing isn’t needed!
Keep that tank moving!
Stabilisation is actually very important in engineering. Tanks are a classic example. The turret of a tank needs to be able to reliably aim and shoot at a target. If the tank isn’t moving, this is not a problem. But insisting tanks stop each time they want to shoot really limits their combat usefulness.
So engineers had to design stabilisation control systems for a tank turret so that while it’s moving, the turret itself remains oriented correctly with respect to its target. Yes a chicken head does it without the chicken having to think about it, but designing one from scratch is not easy! Nevertheless, it is doable, and you can see the result in this old-time video from 1952.
You may have watched (or even filmed) home videos, and the older ones in particular are often wobbly. Although walking is a major cause, even minor shaking of the hands holding the camera can be seen in final product.
In 1975, along came the Steadicam, which is a brand of camera stabilisation system. The camera is mounted on a rig which is supported on the camera operator’s waist. Different systems use springs, shock absorbers and sometimes gyroscopes to keep the camera moving smoothly while the operator walks, jogs, ascends and descends staircases, or even climbs into a crane for shots from above. In the past, if a director wanted a smooth shot, this usually meant they had to use a dolly, which is a mount that moves on a track. As you can imagine, this limited the sorts of shots that could be done.
Nowadays, Steadicam is regularly used in film and television: whenever you are following the actors around in a corridor (such as in The West Wing) or the camera is going around in circles around the actors (such as in ER during operation scenes) you can be sure it’s a Steadicam. Check out this video for a selection of the best Steadicam shots. Yes, unfortunately one is from Twilight…
Chicken + camera = …
Finally, how many of you have put 2 and 2 together and thought “could you make a camera stabilisation system using a chicken?”. The answer is yes, and Destin at Smarter Every Day made one. While it’s unlikely to take Hollywood by storm, it’s definitely worth a look.
The featured image above was made using two photos:
- The photo of the chicken is borrowed from somaholiday under a Creative Commons Licence
- The photo of the tank is borrowed from Rob Shenk under a Creative Commons Licence