Ultrasonic Waves Resonance

I'm not so sure that I'll buy the statement that waves resonate. Waves are flowing energy. Resonance is a property of an item. Typically the dimensions of an item, the temperature, the pressure and possibly other items are needed to calculate the resonant frequency.

I'm not sure what you are asking in your second paragraph, but what I think you are trying to ask is an interesting question. Let me rewrite a question, inspired by your second paragraph, and see if it results in people providing interesting answers.

If waves (sound, light, RF, mechanical vibration, etc.) from one source pass through a wavefront of a similar type of waves from a different source, traveling through a medium of uniform impedance to that wave (air, vacuum, uniform still water, etc.), will the waves simply pass or will they mix and produce sums and differences?

If any type of waves from a single source encounter a change in impedance, will they have both transmission and reflection components similar to what is studied in radio waves? Will there be any mixing (sums and differences)?

Musical instruments, such as a guitar, have acoustical characteristics that are far more complex than six tones being generated by moving six strings of different stiffness and potentially different lengths (as fretted).

Do instruments, such as a guitar, mix and produce sums and differences, or do they just produce various tones and overtones as energy passes through their countless wooden shapes and complex air cavities?

The link you gave explains everything that lingered in my mind. Though there are there for quite a while, hadn't come across until I read the messages from the link. Great.

Interesting link.

The only downside is the weird explanation of interacting of the waves with the listener. I would presume that the modulated frequency is available along the pathway for picking up by anyone with a pair of ears, or indeed just one.

Like the "beat frequency" you sometimes hear from a twin-engine boat or airplane because it can be very difficult to get the exact same RPM from both engines. I tend to notice it with boats more so than aircraft. The 'drone' of the engines slowly pulsates in amplitude over a fairly long time period if the RPM's are close.

Binaural beats ca cause the brain to generate a "phantom" frequency beyond the normal hearing range. It is an illusion created by the brain that combines two different frequencies, one from each ear into the difference frequency and can affect brainwaves. Experiments have been gong on for years ,and still the picture is incomplete on how this occurs and it's effect on the brain.

Perhaps this is the reason for the Havana Syndrome, a mix of multiple frequencies that cause destruction internally to the brain by resonance in the skull? The frequencies could be varied according to the target or swept across a certain bandwidth to affect any target ?

Ultrasonic waves travel for great distances and resonate that may cause havoc

Only if the two objects have the same resonates…

Since every materials and /or objects have an inherent natural resonant characteristic, it is very possible for you to observe and experience the phenomena in a controlled laboratory experiment..

The resultant mixed ultrasonic frequencies produced by the two different resonating tuning forks may only break a glass jar if the resulting frequency harmonics happen to produce enough power to sustain and match the natural resonant frequency characteristic of a particular glass jar...

Going slight off topic. With everything have its own natural resonance, there has been research that was using it to target and destroy cancers. Leaving other tissues unharmed.

this research has been stopped or better word suppressed for a number of reasons, but now I believe it’s started up again, which is great news.

Thanks for that great link! Not Off Topic.

On a larger scale. Tesla was causing buildings miles away to tremble and had to turn off his experiment. It worked similar to a kid in a swing. He emitted one strong pulse into the ground, and when the echo returned, he added another one until they built up to a dangerous level.

I am surprised the military has not used this yet; A super thumper truck as a weapon?

OH NO! Entire cities destroyed?.

I don't recall that ultrasound (ultrasonic waves) travel great distances - they are attenuated more than lower frequency sounds. The article linked elsewhere does explain some impressive range, though. Focused audio energy?

This study (Measurements of atmospheric attenuation at ultrasonic frequencies and the significance for echolocation by bats | The Journal of the Acoustical Society of America | AIP Publishing) shows that "The attenuating effect on the passage of ultrasonic sounds through air ranged from 0.7 dB/m at 30 kHz to 8 dB/m at 200 kHz. These measurements confirm theoretical expectations and earlier observations that atmospheric attenuation is progressively more severe at higher frequencies and that the atmosphere acts as a low‐pass filter for conducting sounds in the frequency range used for echolocation by bats." 8dB/m is a high level of attenuation!

Elephants generate ultra low frequencies that can travel hundreds of miles. They can hear these sounds through their feet.

Elephants were the first to head for higher ground before a tsunami hit. Perhaps having ultrasound detectors could help predict a tsunami in the future.

Whales also, but the media of the oceans helps.

Our sun "communicates" with Earth about every 8 minutes, similar to a parent and child. There is also a similar connecting to the other planets.

Are planets and stars living beings of a nature we cannot conceive, except in Sci-Fi ,of course.

https://www.discovermagazine.com/the-sciences/sci-fi-come-to-life-portals-between-earth-and-sun-open-every-eight-minutes

Does a trumpet or other wind instrument actually have a power gain to emit such a powerful sound from such a small input? I don't think so, so where does the energy come from? How is the sound amplified inside of the instrument?

Tesla said: "If you want to understand the universe, you must understand frequencies."