When I said frequency, I meant wavelength. I should clarify what I said about the modes of the can. His amazing high frequency, high voltage, 'Tesla coils' were basically resonant transformers. You may know about his so-called 'earthquake machine' (not the name he gave it), a mechanical device that could cause an entire building to vibrate at its natural resonant frequency, just like the Tacoma Narrows Bridge that you mentioned. One man dedicated his entire career to resonance phenomena-electrical, mechanical, atmospheric… That man was Nikola Tesla. That's MY fault.Īnd, yes, amplification by resonance phenomena is an amazing concept with remarkable results. I guess you can't do any better than that. I see you listed the science as a separate part. They just were too high for my voice to handle. The neat thing in this is that there are other frequencies that you can resonate the can at. The can in this case is an example within acoustic resonance of a closed tube, and has a series of equations that you can use to calculate stuff. It is what allows us to project voices, to sing, to harmonize, to play instruments, to make speakers. Now acoustic resonance is a part of this that humans have been interested in since forever ago. In this case, it is the air pressure from our voice wiggling the can at just the right frequency. In other words, if something wiggles an object, those wiggles can become stronger and stronger. In physics, if some external force oscillates a system at its natural frequency, the amplitude of its waves can increase and increase. Poetically, we also talk about something 'resonating' with people in the idea that it makes you excited or touches you in some way. Resonance is the reason that kids can pump their legs on swings to get higher, the reason the Tacoma Bridge fell in 1940, and the idea that opera singers can shatter wine glasses. When you wiggle a particular thing just the right way, it can gain more energy so that it wiggles more. The core idea to the most annoying sound in the world is the resonant frequency. This can be a beautiful way to start diving in to the study of waves. I found this regular can vibrated around 320 Hz. I placed the phone speaker into the can, and changed the tone until I could feel the can start to vibrate. I downloaded a free app called 'Tone Generator' where I could generate pure tones from my phone. Don't worry! The last step could have been the end of this Instructable, you can stop here! You don't need to know the science to annoy! But it helps, and is annoying in its own right.

Annoying high pitch sound app