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Janet Jackson had the power to crash laptop computers (2022)

devblogs.microsoft.com

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Re: Janet Jackson had the power to crash laptop computers (2022)

#31

Post by bitwize »

Jtsummers wrote: post #7
hyperhello wrote: post #4

“ I would not have wanted to be in the laboratory that they must have set up to investigate this problem. Not an artistic judgement.” Then what is it?

If you were setting this up in a lab to test you'd be playing the same song on repeat trying to recreate the circumstances and effect, possibly at different volumes and playback speeds and other things until you isolated a particular portion that caused the crash. Then you'd play back that portion. And all of this would be at a level people could hear. So you'd be hearing the same song over and over in an otherwise q…

One of the reasons why Cortana was deprecated was the reports of beleaguered IT professionals having to listen to dozens of chattering Cortanas as they set up a fleet of new corporate laptops.

Re: Janet Jackson had the power to crash laptop computers (2022)

#32

Post by colechristensen »

vlovich123 wrote: post #11

> And of course, no story about natural resonant frequencies can pass without a reference to the collapse of the Tacoma Narrows Bridge in 1940.¹ Yes it can because it turns out it wasn't an issue with resonant frequencies & it's just promulgating an incorrect (but catchy) story. > Just four months later, under the right wind conditions, the bridge was driven at its resonant frequency, causing it to oscillate and twis…

This is a pretty... dubious refutation.

The wind excited a vibrational mode of the bridge which caused it to kind of fail and when parts started breaking more modes were activated and it fell apart.

It's being sold as this gotcha! it's a myth! it wasn't _really_ resonant frequency!

And like... I studied aerospace structures... sure "flutter" is a bit of a better explanation, but saying "resonance" is a myth is a bit silly. Complex structures have lots of vibration modes. The first fundamental frequency can be picked usually and called _THE Resonance Frequency_ or whatever, but it's not like something anybody really places that much emphasis on being the boss in charge of all the vibration.

Myth != terminology nitpick in a layman's explanation

But you get a lot of layman going around correcting people and calling things myths.

It's like Internet people arguing about "just a theory", nobody who actually does science really cares at all about the precise meaning of the word "theory".

Re: Janet Jackson had the power to crash laptop computers (2022)

#34

Post by [deleted] »

vlovich123 wrote: post #11

> And of course, no story about natural resonant frequencies can pass without a reference to the collapse of the Tacoma Narrows Bridge in 1940.¹ Yes it can because it turns out it wasn't an issue with resonant frequencies & it's just promulgating an incorrect (but catchy) story. > Just four months later, under the right wind conditions, the bridge was driven at its resonant frequency, causing it to oscillate and twis…

[deleted]

Re: Janet Jackson had the power to crash laptop computers (2022)

#35

Post by ruthmarx »

netsharc wrote: post #13
jasoneckert wrote: post #10

5400rpm laptop hard drives were notoriously sensitive to external force because of their thin metal construction and low power motor. I remember having a MacBook Pro with a Toshiba 5400rpm hard drive that failed shortly after I rested it on an HVAC unit in our server closet (the HVAC unit happened to be the perfect height off the floor for doing work while standing). Just to be sure that was the cause, I had the driv…

> "Don't put laptops on here." With an explanation why not? I feel like having that, instead of a "Here Be Dragons" note would be more helpful, so someone won't ignore the sign thinking "It'll be fine". Also it'd be funny if the sign is still there even though all* laptops have SSDs now...

> so someone won't ignore the sign thinking "It'll be fine".

If they do whatever happens is on them for assuming that.

Re: Janet Jackson had the power to crash laptop computers (2022)

#37

Post by WalterBright »

vlovich123 wrote: post #11

> And of course, no story about natural resonant frequencies can pass without a reference to the collapse of the Tacoma Narrows Bridge in 1940.¹ Yes it can because it turns out it wasn't an issue with resonant frequencies & it's just promulgating an incorrect (but catchy) story. > Just four months later, under the right wind conditions, the bridge was driven at its resonant frequency, causing it to oscillate and twis…

At Boeing, I worked on proving the elevators would not flutter. It wasn't about a driving force being at the resonant frequency. It was about the interaction of spring rate of the system and the force pushing on it.

The same thing happens if you stretch a rubber band in front of your lips and blow on it. Increasing the stretch will increase the frequency.

Musical wind instruments work the same way.

P.S. the elevators did not flutter in flight test or in service. Phew!

Re: Janet Jackson had the power to crash laptop computers (2022)

#38

Post by kaycebasques »

necovek wrote: post #26
jdiff wrote: post #12

Earlier quoted context omitted.

There's a footnote indicated by the superscript 1 in your quote: > ¹ Follow-up 2: Yes, I know that the Tacoma Narrows Bridge collapse was not the result of resonance, but I felt I had to drop the reference to forestall the “You forgot to mention the Tacoma Narrows Bridge!” comments. Damned if you do, damned if you don't, and damned if you do both, even.

Considering "follow-up" wording, it might have been added later, and might not really be true — but the important thing is that there is a correction now. So it's good a commenter here posted about it, because this might have led to the clarification being put in in the first place.

Follow-Up 2 has been there since at least Dec 2022: https://web.archive.org/web/20221231143310/https://devblogs....

Re: Janet Jackson had the power to crash laptop computers (2022)

#39

Post by WalterBright »

colechristensen wrote: post #32
vlovich123 wrote: post #11

> And of course, no story about natural resonant frequencies can pass without a reference to the collapse of the Tacoma Narrows Bridge in 1940.¹ Yes it can because it turns out it wasn't an issue with resonant frequencies & it's just promulgating an incorrect (but catchy) story. > Just four months later, under the right wind conditions, the bridge was driven at its resonant frequency, causing it to oscillate and twis…

This is a pretty... dubious refutation. The wind excited a vibrational mode of the bridge which caused it to kind of fail and when parts started breaking more modes were activated and it fell apart. It's being sold as this gotcha! it's a myth! it wasn't _really_ resonant frequency! And like... I studied aerospace structures... sure "flutter" is a bit of a better explanation, but saying "resonance" is a myth is a bit…

The movie of the galloping bridge looked like resonant frequency to me.

Back at Caltech, the dorm halls had poured concrete walls. Naturally, some students got a signal generator, a power amplifier, some speakers, and installed the speakers at the node of one of the halls (the halfway point).

Then turned it on, and tuned the frequency until it matched the resonant frequency of the hall. The energy in the halls quickly built up until the entire building was going whomp whomp whomp. Except that the frequency was too low to hear.

You just got a feeling that something was very very wrong. Residences would come out of their rooms wondering what the heck was going on.

A fine prank!

Of course, that was exciting the resonant response with a driving resonance frequency, which is not what happened at the Tacoma Narrows bridge, which had a different way of exciting it as already explained.

Re: Janet Jackson had the power to crash laptop computers (2022)

#40

Post by astrange »

anyfoo wrote: post #17
segasaturn wrote: post #2

This is a fun article but seriously lacking in details... musical frequencies crashing hard drives, including hard drives of laptops within earshot? That's a pretty extraordinary bug so I hoped there would be more elaboration. I also wonder if that patch to block those frequencies is still in effect.

I wouldn't call it a "bug", more "unfortunate physics". Still possible to guard against that, specifically. (There will always be more "unfortunate physics", for example I bet that the hard disk also fails if I smash it against a wall at 100mph, but nobody's going do care designing a consumer HD that stops exhibiting that specific behavior.)

There's more physics issues with the speakers themselves; especially for something like a laptop speaker in a small enclosed space, it's totally possible to blow it out by turning the volume up too high.

There are various ways to protect against this, easiest being to just limit the top volume. If this is done in the official audio drivers then watch out if you decide to install Linux.

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