Fidget craze

[irritant]

The sound might change but not the base frequency.
The scope app can be switched to FFT so you can see the harmonics that create the sound.
The so called fundamental is the lowest frequency in the spectrum. It also has the highest amplitute and that represents the revolutions per second similar to the vibrations of a string on a guitar.
The musical reference tone A4 will sound totally different played on a guitar, violin, flute or piano but their fundamental will always be 440Hz, while the harmonics that make the instrument sound rich and good will be all over the place, especially when the three strings per piano key intermodulate because they ae rarely 100% in tune.

Ah, I see. That's pretty interesting. I like waves and their properties.

If one could keep the little gadget upright, even letting it roll on a frictionless track for a few seconds, or allowing it to reel up ticker tape or string, one can measure the length of course and divide by its "circumference" (it's practically circular whilst spinning of course).

Sorry, I think I'm taking all this a little too far. Didn't mean to annoy you or anyone else reading this.

[Uncle Fester]

The only thought in my head was.... how do I weaponise this?

I am certain you have the skills with your bench grinder to modify this one

[Uncle Fester]

Sorry, I think I'm taking all this a little too far. Didn't mean to annoy you or anyone else reading this.

On the contrary
When I start a thread I am very honoured when posters want to get to the bottom of things, diversify, come up with own ideas... nothing is ever too crazy for me

[Tiny]

I am certain you have the skills with your bench grinder to modify this one

You're right; wouldn't take long to sharpen that. looks like a ninja star weapon.

[lsemmens]

I'm trying to come up with another smart remark that will prompt more discussion on this. However, the only thing I can come up with is how do you know that the Fundamental Frequency of A is 440Hz, you are aware that it which will throw your calculations off.......

[Skepticist]

I once heard talk of an imagined conspiracy related to the standard concert tuning being changed from 432Hz to 440Hz for A. Turns out it amounts to something like a 1/3 of a semitone (on a 12 tone scale) which is a difference very few could even discern but there are still some who'll tell you 432Hz is the frequency of life or something along those lines so the change is plan to unbalance the human race

koff

[Uncle Fester]

The difference between 432 and 440Hz is massive and two instruments tuned to these frequencies respectively will sound awful when played together.
Different story when tuning your oscillators in a synthesizer where you want to slightly detune them to get a more lively, phase shifting sound, but 8hz still sucks.

The esoteric BS artists aside, you will find that many older pianos in homes will be around 430Hz or lower.
Even professional piano tuners will sometimes recommend to keep the tuning lower than concert pitch to avoid the risk of breaking the strings or even worse the pins.
In a few weeks I will have the pleasure to tune an old Australian Beale that uses the notorious Beale-Vader tuning system, so NO WAY will I attempt to tune it to 440Hz.
I might have to lie it down and soak the whole thing in WD40.