I just saw this TV commercial for Bell’s Whisky, in which an orchestra plays Axel F on tumblers of scotch. Quite cool – except of course you can’t make a tumbler resonate by running your finger around the edge like you can a wine glass.¹ So the whole thing was faked.
OK, you expect things in adverts to be faked. I know cars don’t really turn into dancing robots. Nevertheless I’m strangely offended by this. I’m imagining advertising executives with little or no grasp of physics getting really enthusiastic about their idea. So when someone points out to them that it’s not actually a physical possibility, do they change their minds? No, they carry on as if it’s a physical possibility, and fake the cool thing they can’t actually do. It’s like using camera tricks in a magic performance.
Contrast that with the well-remembered ad for Sony Bravia televisions,² where thousands of coloured balls bounce around what look like the streets of San Francisco. That was beautiful, but I wasn’t impressed because after all it’s easy to do something like that with CGI. Only I found out recently, they didn’t use CGI. They dropped one hundred and seventy thousand coloured balls down hills, in San Francisco. Now that is cool.
- All right, we could get into an argument about this if you like. I think it might just be possible if you superglued the tumbler to something solid. Half the trick of making a wine glass sing is firmly holding it down with the other hand on the base, otherwise the energy you’re putting in with your finger is wasted on moving the glass around. I don’t think that merely holding a tumbler down is going to work though. Firstly, you can’t properly grip it so it’s going to move around anyway. Secondly you’re holding it by the part you want to resonate, so you’re damping it.
Even if it was attached with glue though, I’m not sure it would resonate at an audible frequency. Only the sides of the glass would be free to vibrate rather than the whole vessel.
At least, so I imagine. Science, a range of different-sized tumblers, and a clean Formica work surface are calling to me. I must resist…
- [Video] If you have the bandwidth, do watch the HD version.