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Acoustic weapons are directed energy weapons used by the government to incapacitate and end crowds and protests. They use loud sounds to disturb the ears of those affected and some people even think that infrasound/ultrasound can rupture organs. Like found in this question on basilisk induced death Which has some extremely good answers that I recommend reading.

However, that is not what I am interested in, what I am interested in is the use of sound to match the resonant frequency of objects to shatter/rupture/break those objects such as when an opera singer breaks glass with her voice or when the ground is liquified by an earthquake. This is also described by a question called “What sorts of powers would a superhero and supervillain need to (inadvertently) be knocking down skyscrapers?” Where one responder told us of the ability to tune sounds to a frequency to shatter or break objects. (That is also a great question with many great answers from the community)

I am looking for a portable device that can tune into the resonant frequency or resonant frequencies of an object then emit a loud sound to break that object. Additionally I am looking to maximise the amount of devastation that can be caused by this weapon.

Is it even possible to build a weapon like this and if so how would it be made?

Edit:The tech level of this world is modern day earth set in America .

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  • $\begingroup$ I don’t know the rules on using the questions of others so if that is wrong I will delete those parts $\endgroup$
    – Coolcats112
    Commented Apr 25 at 0:49
  • $\begingroup$ Should be fine. You might find there's an advantage in narrowing the question target-wise, then asking a subsequent Q on other targets. Building are going to be quite a bit different in the way you approach them from, say crowds. $\endgroup$
    – Escaped dental patient.
    Commented Apr 25 at 8:06
  • $\begingroup$ one problem is see here, is that in order to damage big, thick structures, you would need a device capable of emitting powerful infrasound. Such devices by necessity must be big to produce the effect. An Infrasound cannon capable of damaging a small house was built. It had a dish the size of a hot tub, and had to be driven on a heavy-duty truck. Anything capable of bringing down skyscrappers etc would have to be even bigger. Ultrasound devices can be much smaller, but they are effectively harmless, not very useful as weapons against anything except glass, at very specific frequencies. $\endgroup$
    – Going Durden
    Commented Apr 25 at 8:06
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    $\begingroup$ There is a way to use pressure waves to damage buildings, and it involves explosives. It is definitely audible, if that helps fit your theme. $\endgroup$
    – Starfish Prime
    Commented Apr 25 at 8:09
  • $\begingroup$ @GoingDurden do you have any references for that? $\endgroup$
    – Starfish Prime
    Commented Apr 25 at 8:10

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Okay - is such a weapon technically possible? Sure...

However - in your question you have outlined two criteria that I believe make it not so:

I am looking for a portable device that can tune into the resonant frequency or resonant frequencies of an object then emit a loud sound to break that object. Additionally I am looking to maximise the amount of devastation that can be caused by this weapon.

and

Edit:The tech level of this world is modern day earth set in America .

Portable and modern day American Tech levels.

Your first problem is the energy drop off from Soundwaves at range: calculator here with some info that may prove useful - in order to have such a weapon have an effective range at least comparable to modern day munitions - let's say that it's gotta have a range of up to 1,000 m.

So, at 1,000 metres it's gotta be dumping enough energy into a structure for it to do something - in terms of damage, some quick googling indicated that 200 decibels of sound would result in damage.

Which means at the source - we need to be putting out something in the order of 260-270 decibels - and remembering - that unit is logarithmic.

Whilst Decibels are not directly translatable to power - I did find a source that indicated that the Space Shuttle, when taking off, was generating around 200 Decibels of noise at 30 metres, therefore we will use this as our baseline.

I should note that NASA says at launch, the Space shuttle is putting out energy to the tune of 13 Hoover Dams - which is apparently 26 Gigawatts.

You are asking for a Portable energy source, that generates in excess of this amount of Energy and we are assuming it is all turned to sound with no losses.

To double check that number - Iron Maiden (Up the Irons!) were using ~500KW to produce 124 Decibels for a concert in Donnington.

What I'm getting at - is in order to produce a sound wave of sufficient power to cause any form of destructive effect, you will need a power source equivalent to a full blown power station.

Which means it is not going to be Portable. Then there is the other issue - dumping all that power into sounds waves is going to cause all sorts of issues for the equipment that generates it.

In short - to produce the kind of energy levels needed to make such a weapon feasible at combat ranges - requires a Technology in excess of our current Tech Level, both in terms of Power and sound generation

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    $\begingroup$ such a power source, if made portable, I believe would have an energy density higher than antimatter which I don't think is even physically possible, so... either way, it would definitely destroy a lot more than its target. Remember that 260 decibels is 1,000,000 times more sound energy than 200, so we're talking about 26,000 terawatts of power. $\endgroup$
    – controlgroup
    Commented Apr 25 at 22:22

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