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 drive replaced under warranty, did the same thing again and it died again after only a short while of using it on that HVAC unit.
After Apple replaced the drive a second time, I instead used a crash cart as a laptop desk and put a sign on the HVAC unit that read "Don't put laptops on here."
We noticed that the macs were rebooting unexpectedly when certain people were in the room. After a bit of observation we worked out that the call button on our walkie talkies could trigger a reboot from a couple of feet away, which turned out to be an awesome superpower if you'd had a gobful from an especially obnoxious student.
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...
If they do whatever happens is on them for assuming that.
Life would be pretty boring if everything were explicit.
Also, sometimes explaining the rationale for a warning can backfire.
An "absolutely no smoking" sign at a fuel depot doesnt tell you _why_ you shouldn't smoke there... If it did, dumb people might think "We'll I'm not refueling at the moment so it will be fine."
"Here be dragons" is vague for a reason.
The model didn't matter, give them a few weeks, and they would stop. Put them aside for a while, they started back.
Never could figure out why, no particular behavior emerged, she changed jobs and houses and I couldn't see a pattern.
Fun that life is still full of weird stuff like this.
Is there an inverse of this?
Often times, people ask me to help them do something on the computer or with other computer related or electronic things. I walk over, touch the equipment without actually doing anything and their problem is instantly solved. Could be a printer that won’t print, even!
I don’t see any links in the See Also section about any “effect” like this.
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.
https://devblogs.microsoft.com/oldnewthing/20220920-00/?p=10...
Even if he's sitting on a different table, the moment I sit down his screen would blank for a few seconds then continue to work normally.
I also get electrocuted easily when I use the escalator. It almost doesn't matter what I wear, so it might have to do with my skin or it's conductivity? But that's just a wild theory that would need to be checked.
Edit: Some research seems to point to the static electricity from the chairs.
> “Surprisingly, we have also seen this issue connected to gas lift office chairs. When people stand or sit on gas lift chairs, they can generate an EMI spike which is picked up on the video cables, causing a loss of sync”
The linked support doc also links to a white paper analyzing the issue. https://support.displaylink.com/knowledgebase/articles/73861...
You get shocked easily when you use the escalator.You wouldn't be electrocuted more than once.
I think I was still in German mode, it's called "electric punch" (Stromschlag) if translated literally, my brain went the easy route and tried to find the closest match.
Too bad the manufacturer wasn't named; I quckly looked through a few laptop schematics from that era and didn't find anything that stood out as being a notch filter.
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 twist uncontrollably. After undulating for over an hour, the middle section collapsed, and the bridge was destroyed. It was a testimony to the power of resonance, and has been used as a classic example in physics and engineering classes across the country ever since. Unfortunately, the story is a complete myth.
> You can calculate what the resonant frequency of the bridge would be, and there was nothing driving at that frequency. All you had was a sustained, strong wind. In fact, the bridge itself wasn't undulating at its resonant frequency at all!
I recommend reading the article but the long & short is it's something called "flutter" and they even have a video of the problem.
[1] https://www.forbes.com/sites/startswithabang/2017/05/24/scie...
> 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.
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.
I would much prefer a reference to the event with the clarification, in the same paragraph, that it is due to a different phenomenon. My 2c.
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".
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.
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!
But there's a follow-up article that addresses all of that: https://devblogs.microsoft.com/oldnewthing/20220920-00/?p=10...
TLDR is it's cheaper to throw your audio quality under the bus than to recall the defective laptops/drives and replace them with a design that works. :(
Getting good audio out of a laptops speaker in 20% hardware and 80% audio filtering anyway. No laptop speaker (even Macs[1]) sounds good without significant processing to workaround the physical limitations of tiny speakers mounted in a non-ideal chassis.
As for other speakers, sound pressure drops off following the cube law. So a speaker millimetres away from the hard drives which have substantially greater impact than speakers outside of the laptop. Of course if you crank the volume enough it’ll eventually cause an issue, but given there doesn’t seem to be widespread reporting of this issue, it looks like that wasn’t too much of an issue.
[1] https://github.com/AsahiLinux/asahi-audio?tab=readme-ov-file...
Then what is it?
https://www.youtube.com/watch?v=aYIwPu50Fic
"For years, scientists have wondered: 'Can you make grown men and women weep tears of joy by playing Tom Jones' It's Not Unusual?' And the answer is yes, you can, as long as it's preceded by 7 What's New Pussycats."
I don't think it's an artistic judgement.
