Years ago—maybe ten or twelve years in fact—I read an amazing article in Scientific American about a dolphin which had learnt to do the dolphin equivalent of blowing smoke rings. It was able to make ring-shaped air bubbles in the water, which it would then play with. The article described such scenes as a researcher blowing smoke rings one side of the glass, and the dolphin reciprocating with its air rings. Creating a ring and then breaking a piece of it off to make a smaller ring. Creating a ring and then swimming through the middle of it. To justify its presence in Scientific American I think there was some discussion of the physics of how the bubbles were able to persist in the water.
Frustratingly, I lost the copy of Scientific American after taking it to work to show someone. But I was intrigued by the article and always wished I could see the dolphin in action.
Well, here it is. And I think you’ll agree that what it’s doing is pretty amazing and makes human-blown smoke rings look very crude in comparison–leaving aside the fact that no horrible carcinogenic smoke is involved either:
How many people do you know who can do that? Probably the number of humans who’ve learnt that skill is approximately the same as the number of dolphins who’ve published papers about fluid dynamics.
I found this video quite by chance: my copy of Opera 10.10 updated itself to 10.51, much less successfully than is usual for an Opera upgrade. So, after rather a long absence, I visited the Opera forums in search of anything which might help me sort out the problems. While I was there I visited a friend’s blog which I’d not seen for a while, and there was the video.
So, two sets of thanks are in order:
- to Yulia, for posting the video, and
- to Opera, for messing up their upgrade so I would visit their site and find the blog post.
Update: It seems that humans can blow these circular bubbles quite easily after all. The clip on this page about vortex rings from ABC television in Australia includes someone doing just that. It also explains some of the physics, and has shots of some more ring-blowing dolphins. Thanks to Andrew Mitchell for the link.
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