[supernova87a]

Hey, I heard about how utility pole inspecting helicopters are able to tell the good/rotten state of wooden telephone poles by the reverb pattern of sound waves coming off the poles from the rotors -- it seems to me the whole field of non-invasive sensing (and using existing/ambient emission sources) is getting pretty impressive.

[motorest]

> Hey, I heard about how utility pole inspecting helicopters are able to tell the good/rotten state of wooden telephone poles by the reverb pattern of sound waves coming off the poles from the rotors

There is a whole field dedicated to this, called non-destructive testing. Modal response (i.e., monitor how a structure vibrates in response to an excitation) is a basic technique that features in multiple areas such as structural health monitoring and service life estimations.

Some mechanics also do this by placing the tip of a screwdriver against a point in an engine and place their ear against the screwdriver's handle. If it's not sounding right, the engine has problems.

Even pottery. You should hear the sound of a pot after you tap it. If it's muffled then odds are it has internal cracks.

[bcrl]

In telecommunications construction we are taught to make ample use of the "hammer test" when working on and around poles. The difference in sound between a good pole, a marginal pole and a completely rotten pole is quite significant.

[klank]

In outdoor rock climbing smacking rocks is an integral part of ensuring the rock you're trusting your life with is in fact worth trusting your life with.

[jajko]

Only if you go outside well-secured sport climbs where you don't have to think about that (but still its a good idea to check the state of bolts for any visible damage due to rot and rust). And even then, some rocks are hollow and still can sustain next 5000 years of literally any climbing on them, some are more solid and will come off if somebody over 80kg hangs on them. So its more about calming one's mind rather than objective good quality test.

Most folks in Europe climb only sport routes, or then do some variant of proper alpinism once on wild unsecured terrain.

[lukan]

"So its more about calming one's mind rather than objective good quality test."

It is a bit more than that, but there is no objective foolproof test, no.

[numb7rs]

It's pretty sobering hitting a rock that looks like an integral part of the wall and it just goes THUNK.

[jacquesm]

You could of course just bury your lines.

[bcrl]

Too expensive where I live. Rocks, hills and trees: the natural enemies of buried fibre and wireless networks. One of my competitors took 6 months to bury a cable in granite that would've been a 5 day aerial job.

[skullone]

I'm so glad you say that. Resi aerial is perfect in most locations. No dig, no service boxes in front yards, under someone's unpermitted driveway pour, ample power easily, a guy in a bucket truck is all you need. Trenchless works well when it can, but even reasonable infrastructure underground is twice as expensive. I love seeing a neighborhood lit up in fiber in 2-5 days and subscribers online at 1-10Gb in soooo many places. Keeps crews busy either way :D

[mschuster91]

> a guy in a bucket truck is all you need

Downside is: a drunk guy in a truck is all you need to tear it down, not to mention natural disaster influence. And it's unsightly AF.

Yes, it's fast and cheap. That's how we got the situation that a backwater village in the midst of the "anus mundi" of Romania has XGPON for a few dozen euros a month, while you're lucky to get anything above 50M VDSL in Germany outside of large urban areas and 200M VDSL in urban areas.

But holy hell it's an eyesore to be in said village in Romania, look out the window and look at a bunch of fiber strung not even from a proper pole but from a tree. Takes the German expression "Kabelbaum" to a whole new level.

[bcrl]

Even if a pole is taken out by a drunk driver that does not mean the cables are going to be severed. I've seen plenty of times when poles had to be replaced, but the communications cables remained undamaged in place due to the strength and tension of the supporting strand.

The bigger issue over the last 5 years in the area where my company operates is the number of dump trucks that leave the bed up. Given the weight of dump truck it is easy for them to pull down multiple poles when they catch the cables, although perhaps they are drunk drivers...

[LargoLasskhyfv]

And outdoor DSLAMs are invulnerable, to cars, vandalism, dog-piss, whatever? Ever walked by one in the middle of the night, when its cooling fans hum? Wanna live near that?

[fh973]

Max. 16Mbit in Berlin-Schöneberg here.

[WorldMaker]

Also where I live (a karst region) other expensive things we deal with are frost lines (frost heave is a real issue; water expands as it freezes, things in the ground don't stay in the ground if ice is expanding into their space) and limestone rock underfoot (sinkholes are a real issue; dig wrong or too deep or not carefully enough and cave in the ground right under you, or worse, someone's house right next to you).

Google Fiber wrecked entire city streets relearning these things the dumbest way possible (then left the street repair bills to the us the taxpayers, because of course they did).

[karlgkk]

Did you invent that thought from first principles without running face first into the brick wall of reality?

[encrypted_bird]

Come on. This is Hacker News: criticism is fine, but make it constructive. No need to make such a dismissive comment. The other replies were also critical of it, but they all gave reasons. Please be better next time, and I hope you have an otherwise great day, friend!

[CalRobert]

When I lived in the countryside on a bit of land and needed to get fiber from the road to my house on my own dime, burying the line was 5-10x as expensive as suspending it.

[tekno45]

its usually more complicated than that.

Repairing becomes a different kind of nightmare.

https://www.youtube.com/watch?v=z-wQnWUhX5Y

[NoPicklez]

And I wonder why that hasn't been commonplace if its just that easy

[cycomanic]

It is commonplace in many parts of the world. Most (all?) of Europe, Australia, many places in Asia.

[zahrc]

And look where that got Germany; my hometown and neighbouring towns are mostly on ADSL or rarely VDSL if you’re lucky, because the big players don’t want anything to do with the cost and legal side.

Local municipalities establish de-facto monopolies and drive prices up, because they offer slightly faster and stable lines.

There is a joint effort by local utility companies in Mecklenburg and they’re trying to make things better, but anecdotally are also challenging to deal with.

My now residence here in the UK is not really rural and for years Giganet/CityFibre/toob promised gigabit soonTM for years and the date got delayed and delayed and delayed.

[broeng]

At least here in Denmark, they seem to have opted for installing bigger "pipes", instead of just laying down some fiber cables. Then in the future they can just push new cables through the pipes. An idea I bet they wish they had gotten the first time around.

[tirant]

That is not the reason that got Germany to have poor telecom infrastructure. We also have poor 4G/5G coverage without the need of any FTTH setups.

There is a common case of excessive bureaucracy and extremely conservative population (thank you, low birth rates) which is hindering any significant development in the country.

[jajko]

Yeah the reason ain't so much some cables in the ground but general byzantine bureaucratic obscurity of a state that you germans created (or allowed to be created) and maintain for yourself. Its far from the only issue stemming form it, and all are just symptoms of underlying dysfunctionalities. Also the population seems to mostly sit around waiting for politicians to fix all problems.

[47282847]

The GDR was deploying fiber, but the west is using capitalism as underlying mechanism so the fiber was left unused and even replaced by copper after reunification because why use the latest technology just yet when you can get people to pay both for the downgrade and the upgrade some decades later!

[bri3d]

Source article (2001!): https://electricenergyonline.com/energy/magazine/4/article/n...

I can’t tell if this ever became a reality; I know of more modern approaches attempting to use thermal and multi spectral imaging to achieve the same goal.

[nashashmi]

What kind of helicopter of what size are we talking about here that can actually get close to a utility pole with wires going across?

[gerdesj]

I live near a helicopter factory and when the spinning towers are in use, you hear all sorts of auditory patterns as you move around the town. When they are test flying - similar and the Police have one and there is an air ambulance too. My Dad's other staff car in the '80s was a Gazelle and in the '70s he whizzed around in a Sioux. I've seen and heard a lot of helos!

I have absolutely no doubt that with some funky signal processing you can do all sorts of things.

[morkalork]

And here I thought living behind a few garages that rev engines all day long was disturbing

[gerdesj]

Its much less disturbing than living under a flight path to an airport. I actually like the sound of a helo - its variable and interesting, as is a piston powered fixed wing aircraft.

Mind you I also lived near RAF, USAAF and Luftwaffe bases back in the day and several flights of Phantoms, Starfighters, Jaguars and Tornadoes and the rest can make quite a din. Phantoms were pretty huge engined beasts with minimal effort made for noise reduction. A "finger four" lighting up their after burners to gain altitude really fast is ear splitting.

[privatelypublic]

HV transmission line inspection routinely has the linesmen crawl out of helicopters onto the lines and back. Granted, as far as I know its the highest skill and most difficult helicopter job.

[jacquesm]

I've seen that in person while in Canada and it is most impressive. The moment they discharge the differential between the helicopter and the line is just awesome. The firebreak clearing operations are also something to behold. From a very safe distance.

[trenchpilgrim]

Look up "Helicopter tree trimming" and prepare to be amazed.

[fsckboy]

also look up "helicopter high voltage wire"

[trhway]

I think you can do it from a distance, just need to have directed microphone (or use laser “microphone”)

[shitpostbot]

That makes sense. It's probably less "doing crazy convolution calculations on how sampled ambient noise changes as the helicopter gets close to a pole", and more "rotten wood vibrates slower"

[gregoryl]

FYI, you've been hellbanned for seemingly 6 years. Probably the account name triggering a spam filter?

Email [e-mail], they may be willing to unban you, so other people can see your posts.

[Xmd5a]

A lot of value in machine learning is in establishing measures by proxy.

[odyssey7]

And yet CT scans that dose patients with radiation are still standard of care.

[_kb]

I don’t think having them stand under low flying aircraft is much safer.

[odyssey7]

A typical CT scan delivers enough radiation to give a healthy person a 1/500 chance of getting a cancer in their lifetime that they otherwise would not have gotten. The risk is higher for children.

We have people working around low-flying aircraft all the time. I’m guessing the associated job risks are better.

When you take those jobs, it’s because you want to make money, not because your life is at risk, there’s information asymmetry between you and the medical provider who is indirectly rewarded for billing for scans, and the overarching medical system prioritized CT scans over MRIs while our engineering culture failed to establish something safer and cheaper.

Would you play Russian Roulette with a revolver with 500 chambers and 1 bullet? What if by doing so a hospital would receive thousands of dollars, and would go on to be paid many more thousands of dollars if you got unlucky?

The cost-benefit trade-off is there, and the powers that be are prioritizing cancer.

[tennysont]

Fascinating---I appreciate you raising awareness. This information was a big update for me, so I looked for a source and found roughly the same numbers (though my numbers were 1/1000, possibly because newer CT exams seem to be slightly safer). From [1]:

> ...93 million CT examinations performed ... projected to result in approximately 103 000 future cancers ... cancer risk was higher in children ... CT-associated cancers could eventually account for 5% of all new cancer diagnoses annually.

Although keep in mind that these numbers do need context. cancer != death. That ranges from cold comfort (in the case painful chemo treatment & years of fear) to a critical factor (based on how the USA diagnoses it, approximately 6% of men will have prostate cancer that does not require treatment).

Based only on these numbers above and my prior beliefs, I would say that that either

A) CT scans are a necessary evil that haven't been adequately replaced

or

B) These numbers less problematic than one might expect, due to some quirk of the data

I generally trust the USA's medical establishment on new treatment, though I've heard that they're slow to clamp down on outdated treatments.

[1] https://jamanetwork.com/journals/jamainternalmedicine/fullar... https://www.nih.gov/news-events/nih-research-matters/radiati...

[odyssey7]

I appreciate you looking into the numbers to verify. The 1/1000 odds seem better, though still important.

Also, framed another way, 5% of cancer cases caused by CT scans would mean that 1 in 20 people in the cancer ward were placed there by a CT scan. Or alternatively, phasing out CT scans would prevent 1 in 20 cancer cases, with prevention being worth more than a cure for every 1 cancer patient in 20.

[iancmceachern]

Do you have any other wavelenghts of radiation that pass through flesh but not bone and metal we can use instead? If so speak up please, otherwise we need to keep using x rays because, physics.

[odyssey7]

MRI.

If we had gotten our heads out of the sand on pushing CT scans as the answer, years ago we might have progressed further on other tech too.

E.g., photons: https://medicalxpress.com/news/2025-06-scientists-entire-hum...

[iancmceachern]

Yeah but that's different. It's great for soft tissue (that has water which can be vibrated by the magnetic field) buy less great for things like bone. Hence why CTs are still used. Also, the magnetic field makes it so things like intraoperative imaging is very difficult.

[odyssey7]

When bone is what needs attention, you can use conventional x-rays in all but specialist cases. A single x-ray image is typically far less radiation than a whole CT scan.

And yes, you can still see bone in an MRI. A related question is, how well can you see soft tissue in a CT scan?

CT scans are routinely used to diagnose soft tissue problems, where they are the wrong tool for the job: an MRI would be more ideal. CT scans in these situations expose the patient to avoidable cancer risks while compromising the level of insight provided to the medical provider.

Interoperative imaging is another specialist use case. The need for CT scans in specialist situations speaks to the failure to develop alternatives with lower cancer risks. Also, the need to use a CT scan in certain situations does not mean that the CT scans should be used in other situations.

[nightfly]

You get a lot more detailed information out of a CT scan

[odyssey7]

Not more detailed than an MRI. And the longer we push CT scans, the longer we delay the advancement of less invasive technologies.

[jacquesm]

Yes, what do those doctors know anyway... /s