WiFi signals can measure heart rate | Hacker News Reader

WiFi signals can measure heart rate

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467 pointsbookofjoe262 comments

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.

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?

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

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"

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

Email hn@ycombinator.com, they may be willing to unban you, so other people can see your posts.

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.

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

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.

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

also look up "helicopter high voltage wire"

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.

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.

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.

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

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

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

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

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.

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

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...

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.

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

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.

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...

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.

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.

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.

You could of course just bury your lines.

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.

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

> 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.

Max. 16Mbit in Berlin-Schöneberg here.

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...

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?

GPON outdoor units don't create any noise, they are purely passive.

Yes. But you've written about ugly and vulnerable infrastructure am "Arsch der Welt"/"JWD" first, and lamented about limited availability and performance of pink Telecomicstan VDSL in Teutonistan second. I've written about the latter, since I've heard them, because they are not passive.

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).

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

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!

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

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

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.

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.

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.

Cell towers need 'backhaul' too. Can't have them all microwave meshed.

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.

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!

https://de.wikipedia.org/wiki/Optische_Anschlussleitung was not a thing of the GDR. Though one could think so, because of the ...errm... let's say 'mismanagement' :-)

That's what you get with arrogant and ignorant large bureaucracies, anywhere, anytime :-)

There was fiber deployment in the GDR and plans to extend it already before the OPAL project, which came after reunification. I remember our East German CS network professor talking about it with passion but fail to find information online. Which doesn’t surprise me, since history is written by the winners. I trust his personal stories more than the lack of information online.

It could be. Even much stuff from the 'winners' from before common internet access is lost ;->

OTOH, considering how well the 'megabit-chip' went, I'm wondering wtf they'd do with fiber, at the times? For the military, agencies, ministries and some universities maybe, but for the masses? How common was the 'stinknormales telephon' in households, back then?

its usually more complicated than that.

Repairing becomes a different kind of nightmare.

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

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.

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.

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.

"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.

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

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

> 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.

Can't help but think of the Star Trek TOS episode where Kirk is accused of murder and they find the "murder victim" in the ship by identifying and isolating heart beats until they discover he must still be aboard. It's been almost 60 years since the episode came out, but still sorry if that's a spoiler

Classic Star Trek (speaking as a fan). They can scan an entire planet to find a lost crew member, but can’t tell how many people are on their own ship. And they have universal audio surveillance on the ship but still have to use wall intercoms.

My phone can hear me and answer whenever I talk to it, but I still prefer to push a button first (kinda intercom), or even just type :)

The Star Trek series require a lot of suspension of disbelief, especially since in the years after it came out real life technology surpassed the stuff depicted in there. Like, in TNG people walking around with glorified e-readers but having to go to the big computer or to ask Alexa things instead of just tapping on their screens.

At least they got OLED style touch screens, and for a while it looked like everything would go that way but at least in cars some are going back to physical buttons.

One thing that I feel actually became more believable with new technology is the plot device where only one character can perform a certain task, but then all they really do is tell the computer to do it. For example, in Voyager, they make a big deal about how Harry Kim is the only one who's able to make complex holograms. That originally seemed unrealistic; but now, with the amount of work some people put into prompt engineering for LLMs, it actually seems kind of plausible.

> At least they got OLED style touch screens, and for a while it looked like everything would go that way but at least in cars some are going back to physical buttons.

On that note, physical buttons are tactile and easier to navigate while driving and thus safer. You don't have to take your eyes off the road and worry about a fussy touchscreen registering your tap. You just feel around for the control and manipulate it.

The appeal of a touchscreen is that you can change the interface. It can assume a wide range of control panels, which, in a car, isn't always useful. For functions you need immediately, you can't beat a fixed physical widget.

Now, what would be interesting is a surface whose physical texture and physical controls could be dynamically changed and reconfigured. So, a flat surface becomes a series of buttons, and then maybe a rotating knob in the next. Perhaps tactile holograms. I don't think something like this could beat physical controls for reliable and lasting function either, however.

https://www.advancedsciencenews.com/clickable-buttons-that-r...

(2023)

https://www.engadget.com/2015-09-23-geltouch.html

(2015)

That's bad because you need to remember several layouts at once. While with a physical one you are done with your muscle memory.

I mean, they have GRAVITY PLATING

We could many centuries from now have "warp drive" but GRAVITY PLATING is completely implausible

Yet it makes every episode of each ST series watchable so we just accept "the future"

They invented the transporter because they didn’t have the special effects budget to handle landing a ‘spacecraft’ each time on the planet. Gravity plating is pretty mellow hah

Why is something that applies a roughly uniform downwards force to things in an area above it (or maybe between two plates of it?) implausible.

It doesn't come with nearly the same level of implausibility (causality problems) that FTL does IMHO.

At least they mention it. Unlike in both old and new Battlestar Galactica. Ships there are just able to keep people walking like on a planet's surface.

In the new TV series Alien Earth, the low resolution CRT monitors and clunky keyboards aboard interstellar spacecraft really stand out. Presumably it's an homage to the 80s' movies.

Mostly im sure, but using older and simpler technology does have benefits when it is going to be used on ships traveling for decades at a time through space. Seemingly the mass of ships in the Alien universe doesn't seem to matter too much so chunky old tech that is easier to repair and hopefully more robust could make ships both cheaper and more likely to return from the apparently not uncommon ship disasters.

> Like, in TNG people walking around with glorified e-readers but having to go to the big computer or to ask Alexa things instead of just tapping on their screens.

PADD was still futuristic enough at that time but what they didn't predict behind scenes was multitasking in software. Characters in old series were seen working on multiple devices like on multi-page documents. Tho, you can always say that it was just a gimmick to show character being really busy.

Some 30 years ago there was this Australian tv show for kids created where by sheer luck a damaged satellite fixed itself and let group of random kids around the world magically have a Zoom-like meetings for education and... making art thieves lives miserable. Prop department utilized still new at that time Sharp OZ-7000 (one of first such devices, before even PDA was coined) as communication device equipped with small colored LCD and weird looking "gem" camera. Back then that was a futuristic fantasy that seem impossible. And here we are, with smartphones that can make video calls at ease by Internet for last few years.

> Like, in TNG people walking around with glorified e-readers but having to go to the big computer or to ask Alexa things instead of just tapping on their screens.

People do that in real life all the time even with the ability to do everything on one handheld device today. People pick up preferences for using "apps" on specific devices, or have multi-tasking use cases where flowing across devices feels nice or makes the most sense.

For instance: Using an iPad to read a kitchen recipe and calling to Alexa or Siri on a nearby Echo or HomePod to set a kitchen timer while watching a show on a kitchen screen, say powered by an Apple TV. The iPad could picture-in-picture the show and track the timer and show the recipe all at the same time, but that's not the experience everyone wants. It's not even the experience that Apple wants to sell to people. If you've got an iPad and HomePod in the same room and call for Siri, the software is built to prefer the HomePod and its smarter array of microphones to listen for what comes next. It's better, more dedicated hardware to help the software deliver a better experience.

It's great that one device can do everything, but we rarely want to use one device to do everything when we don't have to. Especially because human memory is contextual and spatial it becomes easier to remember where we "left" things if they are on different devices in different places.

Especially in TNG it feels like a lot of the screens are designed for exactly that: the screens can change to other displays but most often don't because they are very specifically tailored to each specific place they are. That seems somewhat intentionally designed to help the human memory and better muscle memory, knowing what we knew in the 90s and knowing what we know today. "I don't want to lose my place in this recipe just to set a timer or to catch up on TV" is a human problem and TNG showing "I don't want to lose my place on this PADD so I'll ask the computer to do something or walk to engineering to touch a specific dedicated panel that my fingers have already memorized" is maybe just a reflection that in Star Trek's future humans are still, you know, human.

Oh, it gets worse. Either Kirk or Spock should have hung for that episode - not for the thing Kirk was on trial for, but for leaving the entire ship unmanned, and for allowing that guy to terminally sabotage it, all to do some theatrics for the judge and jury. That is a criminal level of negligence - surely it was in violation of some minimal crewing requirement for a vessel of that size.

I also have to wonder what the 'dead' guy's plan was after Kirk would get convicted for his death. Presumably he'd need to climb out of whatever rathole he was hiding in for breakfast, and I'd presume someone on the ship would notice that the dead guy is alive, and that the conviction should be overturned.

---

Truly, the level of and attention to security on the Enterprise-C was shameful. In "The Conscience of a King" (an excellent episode), one of the traveling actors manages to - not only steal a weapon - presumably from the armory - but also rig it to explode and plant it in the Captain's quarters.

Starfleet in that era should have seriously formed an independent, no-bullshit, no-nonsense commission to ask the relevant enlisted and commissioned officers pressing questions, like 'Did you, or did you not leave the hatch coaming on Deck C open, thus allowing an enemy agent access to the arms locker? Are you in collusion with enemy agents?'

Maybe it’s just a Boomer thing? (Sorry, couldn’t resist the BSG / trek crossover joke).

You mean this one? https://i.imgur.com/PmeTa4c.png

Boomer was being investigated one of the first episodes for leaving the hatch to the water storage/recycling unlocked, where explosives were then detonated. Maybe it was the armory--it's been quite a few years, but close enough for a pun.

I meant the meme!

But yeah, the story went pretty much like this. I prefer that second episode much more than first one with 33 minutes theme.

There's a single DS9 episode[0] where they reveal that the Captain can actually spy on everyone on the ship at once. Like tap into a video feed and listen to conversations. But then we never see this happen again.

My headcannon for this is that even though it's technically possible, it's so unethical they just choose to never do it.

[0] https://memory-alpha.fandom.com/wiki/Valiant_(episode)#:~:te...

The mirror universe captain of the Enterprise-C uses that exact functionality, in conjunction with a disintegration beam to quietly disappear problem crew members.

Or beam them and delete the buffer

"Humans are ethical and behave morally" is a core idea behind every Star Trek episode featuring the Enterprise. Its relentless optimism is almost innocent in nature...

DS9 is great because it showed us the darker side of the federation. They can afford to be like this because they've got Space CIA committing atrocities behind the scenes since day one.

>My headcannon for this is that even though it's technically possible, it's so unethical they just choose to never do it.

IF theres something unethical that they choose not to do, you can be sure Sisko is doing it.

Odo spies on Quark in Season 2. Think it was the Maquis two-parter? He doesn't care about Federation ethics early on though.

Hah but the majority of the time Odo spys on Quark by morphing into a common place object like a table or glass. My new headcannon will have to be that Quark keeps removing Odo's spy sensors. Odo definitely would use them if he could.

Pretty sure Odo spied on Quark all the time - kinda weird but useful hobby

I don't remember that episode. But it does not surprise me that the Cardassians would build that feature into their station.

This was actually on a Defiant-class ship being captained by Starfleet recruits/kids! The captain was just an older cadet that the original dying captain placed in command. Which fits with my headcannon that real Starfleet captains wouldn't so this.

What happened to capitalism in Star Trek? Shouldn't the data be sold to the highest bidder?

You took away my ability to make a cheesy "spoilers!" comment, which is arguably worse than having spoiled the episode (thanks, btw).

Humorous summary: https://www.mezzacotta.net/planetofhats/episodes/0020.html

Everyone’s heart is different. Like the iris or fingerprint, our unique cardiac signature can be used as a way to tell us apart. It can already be done from a distance using lasers [1].

[1] https://www.technologyreview.com/2019/06/27/238884/the-penta...

https://www.theregister.com/2025/07/22/whofi_wifi_identifier... | https://news.ycombinator.com/item?id=44685869

> Researchers.. developed.. a biometric identifier for people based on the way the human body interferes with Wi-Fi signal propagation.. CSI in the context of Wi-Fi devices refers to information about the amplitude and phase of electromagnetic transmissions.. interact with the human body in a way that results in person-specific distortions.. processed by a deep neural network, the result is a unique data signature.. [for] signal-based Re-ID systems

Tracking people walking through malls. Or even better: tracking everyone in the sidewalk of a NYC street after they commit a crime and where they end up at.

Ah yes, tracking everyone. The one system that only leads to good outcomes.

Well, we know that tracking "everyone" would only lead to tracking a subset of everyone. A subset with a lot less money and power than those in charge of the tracking. Much like the guard or observer in the panopticon.

It might cause people to carry WiFi jammers.

> WiFi jammers

Any active RF broadcasting device would function as a "look at me" homing beacon.

Don't we have phones for that?

That only catches the stupid criminals, which to be fair is most of them.

Not sure how many criminals that catches, but phones most certainly track everybody.

The CEO killer in NYC could have been tracked this way.

Or they just used the services of DomainAwareness.com

fingerprints don't change, heartbeats do. Every heartbeat is different so it'd be difficult to even tell which heartbeat is yours for any giving signature.

from the linked article: But gaits, like faces, are not necessarily distinctive. An individual’s cardiac signature is unique, though, and unlike faces or gait, it remains constant and cannot be altered or disguised.

This is just a dedicated RF emitter combined with a dedicated receiver. The fact that is it uses WiFi hardware is probably just because that's the cheapest and most available hardware for the researcher to work with. There is no indication in the article that the WiFi can actually be used for transmitting real data at the same time; that a non-dedicated WiFi source can be used; that it works when there are many people between transmitter and receiver.

Therefore the ideas that this might apply to real-world situations and use existing WiFi infrastructure, are a stretch given the information that's been shared.

It basically doesn't seem like a big deal to demonstrate what has been demonstrated.

Research doesn't always seem like a big deal. In this case, using CSI extracted from standard wifi packets (beacons, data frames, etc.) from commodity hardware is the core of the "big deal."

In principle, any packet that carries data can also be used for sensing, though, as you mentioned, this isn't what the researchers demonstrated. However, for years, this kind of thing was studied using special multi-antenna Intel cards to get a clean signal. Getting this level of accuracy from such a low amplitude signal from a single antenna on commodity hardware like an ESP32, is the actual breakthrough. It proves the concept is sound before tackling the much harder problem of using a standard home router amidst other traffic or isolating multiple targets in a room.

Mmwave heartbeat sensors are like $2 at retail pricing. This is commodity stuff, I fail to see how adapting it to a new radio is any kind of big deal.

Using channel state information is not about "a new radio." CSI is a byproduct of existing WIFI standards/infrastructure.

CSI does require a supported chipset, like an ESP-32. However, if an IoT device is already using an ESP-32, for example, one would not need to add dedicated hardware (like an mmWave MR60BHAX) to be able to do things like presence, breathing, heart rate, and location detection.

As a hobbiest/ESPHome user, I have lots of ESP-32s and not lots of mmWave-s. As a business, I'm already shipping with an ESP-32 and I don't want to increase my BOM.

Besides this, I find this research to be a big deal as it has implications for privacy and security. Your biometrics can be collected using existing widely-deployed hardware using existing internet standards. Your smart toaster can indeed be spying on you in more ways than you think.

But anyway, using CSI for sensing will soon be old hat. IEEE has granted approval to the 802.11bf WLAN Sensing working group to define standards for exactly these types of applications. Taking what's currently an artifact of an implementation detail, and turning into a first-class feature.

Edit below

I want to point out another thing: "clinical-level heart rate monitoring with ultra low-cost WiFi devices" can be lifesaving in situations where clinical-level heart rate monitoring is otherwise unattainable.

Human vital signs detection can be useful in earthquake situations. Measuring through walls of concrete is difficult, however, so a new radio is needed (lower fequency and/or more sensitivity).

> This is just a dedicated RF emitter combined with a dedicated receiver. The fact that is it uses WiFi hardware is probably just because that's the cheapest and most available hardware for the researcher to work with.

Ok.

> There is no indication in the article that the WiFi can actually be used for transmitting real data at the same time

So? No one said it was.

> Therefore the ideas that this might apply to real-world situations and use existing WiFi infrastructure, are a stretch given the information that's been shared.

What? First you say it's trivial/obvious, and now it's impossible? Decide on your critique.

The dominant themes in the thread relate to using existing WiFi infrastructure in real world environments. I thought it would be obvious that I was critiquing this line of thinking. Obviously not.

Real-world applications benefit from recent on-device hardware like NPU or Apple Neural Engine.

Intel demo on commercial laptop (2022), https://news.ycombinator.com/item?id=45130061

Qualcomm human-in-home positioning demo (2021), https://www.youtube.com/watch?v=xNmnqCsvMTU

No clunky wearables? No chest strap on the treadmill? Heart rate and respiration? Monitors everyone in the house simultaneously 24/7 on a cheap rpi? I hope this doesn't take years to come to market because this seems incredibly useful.

Could also see the value of this for caregiving. I caretake for my grandmother, and even something as simple as keeping airtags on her keys has been a challenge. It would be impossible for her to consistently wear some wearable health device / life alert / etc. passive health monitoring that’s not intrusive would be amazing.

Not an expert, but I suspect for many there are warning signs that someone may die in their sleep (or exercising, or ???) long before the heart finally quits. This seems like a great way to monitor for that.

when I'm old and going to die, "in my sleep" would be top of the list of ways I would want to go, (during sex is likely not going to be an option)

May we all be so lucky but "old" is relative in this case. An acquaintance did just that... in his 50's :/

If it’s during sex, would you want your sex partner to also die at the same time? Seems like it would be a troubling experience for the other person.

I’m an EMT, so not the deepest level of knowledge, but certain progressive things that will kill you (such as sepsis) would show noticeable trending in basic vitals like heart rate and respiratory rate. And sepsis is also common in geriatrics (catheter / surgery / G tube -> infection -> sepsis)

Seems like it would be really useful in a hospital setting as well. Instead of having to wear the heart rate monitors, etc. during recovery or a stress test it could be wireless.

I've not followed any evolutions in this area, but there's a cool paper from 2014 about using WiFi channel state information to detect 87%(!) of falls in an experimental condition[1]. It's been a while since I read the paper, and I no longer have access, so caveats aplenty, but it's one of those things that pops into my head sometimes and I wonder if it's seen any real-world deployment.

[1] - https://ieeexplore.ieee.org/document/6847948

There's plenty of wristbands and rings with health tracking.

There are positive sci-fi use cases, but ONLY IF the data and automation are entirely under control of the human subjects, e.g. self-hosted home server, local GPUs, local LLM, offline voice recognition, private 3D imaging of home and human, etc.

Comcast renting out wifi hardware to all of their customers, and already bringing that technology to the masses should be concerning to you then.

Sensing is (sadly) already part of Wi-Fi 7. If you have a recent Intel, AMD or Qualcomm device from the past few years, it's likely physically capable of detecting human presence and/or activity (e.g. breathing rate, keystrokes, hand gestures). It can also be done with $20 ESP32 devices + OSS firmware. The open questions are on custody and legal usage of CSI measurements, not their existence.

But think of how much money they can make by selling your health data to insurance companies!

Yet another tool for our surveillance capitalism overlords to figure out when people are having sex.

Alexa: "I sounds like you're having sex. Would you like me to play Vivaldi's Concerto Grosso in D minor on Spotify and schedule a breakfast delivery through GrubHub?"

I don't want the data under my control - I want it under my doctors control. Except if it decects a coming heart attack or such, then notify every emt.

If you have control of your data, then you can delegate to doctors, EMT or other agents.

I want my doctor as agent to delegate to other specialists without consulting me. Most of the time it isn't needed but I don't want to be bothered for 'just double checking this is nothing' which should happen at times.

When you say, "I want", you need initial data control to give that instruction.

You can delegate to your doctor the right to delegate to other specialists without consulting you.

Other humans can delegate to the agents of their choice.

This is why the first step is for you to have control of your data, then you can specify/revoke who-does-what with it.

WiFi RSSI hacks (WiSee (2013),)

Linksys Aware (-2024): https://www.google.com/search?q=Linksys+Aware

From this thread https://news.ycombinator.com/item?id=45129817 :

> 802.11bf

802.11bf: https://www.google.com/search?q=802.11bf

"Whole-home gesture recognition using wireless signals" (2013) https://dl.acm.org/doi/abs/10.1145/2500423.2500436 .. https://scholar.google.com/scholar?cites=1386163076039493879...

From https://news.ycombinator.com/item?id=38246722 re: a stylus with accelerometer with many degrees of freedom and inertial measurement:

> /? wireless gesture recognition RSSI:

> /? wireless gesture recognition RSSI site:github.com

> Awesome-WiFi-CSI-Sensing: https://github.com/Marsrocky/Awesome-WiFi-CSI-Sensing

> 3D Scanning > Technology, Applications [...]

Whole-home gesture recognition sounds really cool! Has anyone actually got this running?

IDK what the error rate of gestural recognition with Wifi is. FWIU the market for e.g. the Magic Leap gestural peripheral just wasn't there. That paper says 2013.

Marsrocky/Awesome-WiFi-CSI-Sensing#gesture-recognition: https://github.com/Marsrocky/Awesome-WiFi-CSI-Sensing#gestur... :

> "Real-time Cross-Domain Gesture and User Identification via COTS WiFi" (2025)

> "One is Enough: Enabling One-shot Device-free Gesture Recognition with COTS WiFi" (2024) https://ieeexplore.ieee.org/abstract/document/10621091 .. https://scholar.google.com/scholar?cites=5141488558554953622...

I feel this technology would creep people out so much that anyone in the wifi space would be actively hostile towards these things. Maybe they'll lock it behind patents? I doubt governments would want this to become common knowledge either.

It has been IEEE standardized and shipping commercially for several years.

Seeing that it works for a ESP32 chip I would say that its very likely to work on a smartphones's wifi chip though the article didn't say. Many people carry phones with them everywhere and all the time. You could build a very impressive profile of a person. It could be used to see when they get excited, scared, angry, etc at depending on what they view on the phone, the phone call they received, where they physically located on the earth, who they are around (by looking at identities of other phones near them) and properly other things as well I have not thought of.

This is nothing new. Wifi signals have been used to detect objects, people and animals, gait analysis[1], read keystrokes[2], monitor breathing and heart rates[3], "hear" conversations[4], etc for at least a decade now.

https://news.ycombinator.com/item?id=12353605

https://www.theatlantic.com/technology/archive/2016/08/wi-fi...

https://archive.is/XnHUV

1: https://ieeexplore.ieee.org/document/7457075

2: https://dl.acm.org/doi/10.1145/2789168.2790109

3: https://archive.is/mFSDq

4: https://archive.is/sNVcM

[edit: publicly announced] commercial deployment into homes and offices is new.

Or is it?

Indeed, this same principle has been shown to work with sound waves and not just RF waves. There was a paper a few years back that used car speakers and the microphone to be able to detect the number of people in the car for the purpose of detecting children or pets left in hot vehicles.

Generally I think this is called "tomography" (https://en.m.wikipedia.org/wiki/Tomographic_reconstruction) i.e. the reconstruction of higher dimensional data from lower dimensional data. Your brain can do it automatically in a lot of cases. For example if you see the shadow of a rotating cube on the wall, your brain can reconstruct 3d information about the cube even though you only have access to a 2d projection

Have you gotten any of these to work? A few years ago I was tasked with investigating these kinds of techniques for a client (it was something cool and benign but I can’t say what due to NDA) and the big papers people are referring to when they mention this all had either huge asterisks or huge methodological flaws.

Getting it to sort-of-work is fairly easy. Getting it to work well on off-the-shelf hardware without a precisely controlled environment is hell.

For practical applications right now, you'd want a dedicated radar unit at 24GHz or so, probably with two separate reception paths too.

Eventually, we might get usable radar functionality in default Wi-Fi chips with 5GHz/6GHz Wi-Fi and MIMO - but it's not there yet.

In my experience aallll of these fancy "we can measure things that sound impossible" papers come with the asterisk "in perfect lab conditions".

> “The signal is very sensitive to the environment, so we have to select the right filters to remove all the unnecessary noise,” Bhatia said.

AKA "it barely works and we had to filter the signal to the gills to get anything at all".

It's a really impressive tech demo but the article is selling it as if this might actually work in the real world and it clearly won't.

i get asked about stuff like this from time to time and i always say "no, that's impossible" because i have ethics. The common retort is "well, i heard it was being used at <x>." and a client never contacting me again, which is fine.

Try using this you just need an esp32 devkit nodemcu style pcb. It measures movement though.

https://github.com/espressif/esp-csi

802.11bf is working on sensing applications:

> With recent advancements, the wireless local area network (WLAN) or wireless fidelity (Wi-Fi) technology has been successfully utilized to realize sensing functionalities such as detection, localization, and recognition. However, the WLANs standards are developed mainly for the purpose of communication, and thus may not be able to meet the stringent requirements for emerging sensing applications. To resolve this issue, a new Task Group (TG), namely IEEE 802.11bf, has been established by the IEEE 802.11 working group, with the objective of creating a new amendment to the WLAN standard to meet advanced sensing requirements while minimizing the effect on communications. […]

* https://ieeexplore.ieee.org/document/10547188

> In recent years, Wi-Fi has been shown to be a viable technology to enable a wide range of sensing applications, and Wi-Fi sensing has become an active area of research and development. Due to the significant and growing interest in Wi-Fi sensing, Task Group IEEE 802.11bf was formed to develop an amendment to the IEEE 802.11 standard that will enhance its ability to support Wi-Fi sensing and applications such as user presence detection, environment monitoring in smart buildings, and remote wellness monitoring. In this paper, we identify and describe the main definitions and features of the IEEE 802.11bf amendment as defined in its first draft. Our focus is on the Wireless Local Area Network (WLAN) sensing procedure, which supports bistatic and multistatic Wi-Fi sensing in license-exempt frequency bands below 7 GHz (specifically, 2.4, 5, and 6 GHz). We also present an overview of basic sensing principles, and provide a detailed discussion of features defined in the IEEE 802.11bf amendment that enhance client-based Wi-Fi sensing.

* https://www.nist.gov/publications/ieee-80211bf-enabling-wide...

* https://www.cognitivesystems.com/how-does-802-11bf-enhance-l...

(See also perhaps IEEE 802.11bi, Enhanced Data Privacy.)

802.11 Blue Falcon

People are suggesting this to continuously monitor vitals. Others think that is a privacy problem. There might be an even bigger problem: continuous vitals monitoring might lead to over-medication and perhaps be worse for patients.

One of the reasons vitals are such a good diagnostic tool is that we monitor them specifically when we already suspect something might be wrong. Monitoring healthy patients reveals the large variation in vitals -- some that might even appear problematic.

We know this among other things because we have accidentally experimented on babies and mothers during delivery. Some clinics have a policy to put them on continuous monitoring the moment they arrive and they get treated for more things with worse outcomes when they're otherwise healthy. Maybe this is confounded (some clinics overmedicalise everything -- both monitoring and treatment) but I like the intuitive explanation that excess monitoring causes excess treatment.

The privacy problem is THE problem. That's the 362 kg elephant in the room.

I monitor kitten health while fostering. Continuous monitoring can be done to establish a baseline. It requires the right mindset, though. I look at the overall picture of a kitten's health while considering changes in status. The "overall health" is the part doctors are missing, because science is systematic (step-by-step) and not systemic (whole system), therefore medicine is systematic too.

(100% of my foster kittens have survived (out of 25) and I specialize in fostering the worst cases.)

It's galling that this press blurb only focuses on happy (supposed) health monitoring benefits, and fails to address the privacy concerns in the slightest.

This can be abused in so many ways, like watching how people's heart rates change then watching an add, or browsing a selection of goods in the shop, and making viscerally targeted advertising. Or burglars detecting whether people are at home.

Soon we won't just have to worry about unpatched wifi routers being parts of botnes, we'll have to worry about them tracking our locations and excitement levels and selling them off to whoever.

new and more efficient markets

I was just in another thread with someone claiming that without pervasive ads things would be worse than Soviet Russia (sic). I don't doubt ad+tech giants will get their hands on any source of data they can.

This is the study https://bpb-us-e1.wpmucdn.com/sites.ucsc.edu/dist/d/1595/fil...

Hey guys I am the high schooler who developed this let me know if you got any questions I'd be happy to answer them

Congrats, very impressive!

The linked article is a bit light on actual details – could you share the paper/preprint maybe?

Thanks!

https://ieeexplore.ieee.org/abstract/document/11096342

That’s the official paper link. Sorry it’s not open access.

Too bad :( Though I’ve just found a PDF here in the open: https://news.ucsc.edu/wp-content/uploads/2025/08/Pulse_Fi_sh...

Oh great- I forgot we had the open pdf posted somewhere

Awesome job!

A couple questions:

- How was the training/testing data split? Was it split window-wise or participant-wise?

- How does the system perform at elevated heart rates? Seems like it was mostly tested at resting/normal heart rates

1. in this iteration we used a 64% training 16% validation 20% testing split. In our current work we are testing with 10 fold / leave a subject out to get better analysis. 2. the esp dataset had heart rate up to 130 which is relatively high, and the raspberry pi data had people running in place etc... where the heart rate is higher

1. The collected data set has one person in between receiver and transmitter. Will the same model work if there is multiple people between receiver and transmitter?

2. If anyone has a heart rate outside the range of 48-130? can this model detect that heart rate?

1. We are currently working on multi person, this iteration doesn't support it. 2. The range was just what we had in this dataset, if we exposed the algorithm to a broader range, it would work for that too.

There is a wonderful channel "Quantified Scientist" (https://www.robterhorst.com/, mostly YT content) with benchmarks of smartwatches and trackers against EEG and more profesional heart monitors. It would be interesting if he could benchmark WiFi as well.

AS, in short, it is easy to measure pulse or sleep somehow. It is hard to measure it well consistently (pulse when someone is running, biking or weightlifting, sleep when people sleep with others, move, etc - or lay sleepless).

Apparently wifi can also see through walls:

https://news.ycombinator.com/item?id=37469920 (from the same org)

ucs(c) vs ucs(b) FYI

Close enough

I guess it is good to be aware of what’s possible. But all this stuff about using WiFi to measure things about people—it’s a bit creepy, right? I mean, to state the obvious, we (as a society) have got a bunch of poorly patched or corporate controlled WiFi routers attached to the network. What a surveillance catastrophe waiting to happen.

I mean, heart rate? Do we have a giant network that can tell where everybody is and whether they are having a strong emotional response to anything?

You are not exaggerating to be weirded out by this. It’s already being used to monitor people in their homes by law enforcement.

Your comment should not be gray, as you've stated a rarely known fact. I used to have an old brochure with the exact model number of the device you refer to. And it's been around for well over a decade.

I'll try to find the model to rescue your post. People can be so fucking unreasonable here it makes me sad.

But I know exactly what you're referring to.

Note: it's also worth considering its applications in parallel construction and that it's indeed so rarely known, that it doesn't require a warrant.

Edit: https://en.m.wikipedia.org/wiki/Range-R

Edit II: they were, at one time around 2011 definitely having a lot of fun with these devices in my town here in Florida.

Edit III: also of interest, https://camero-tech.com/

Edit IV: https://www.policemag.com/technology/article/15541542/first-... - Detex Pro, by MaXentric

Thank you! I wanted to provide a source, but I have literally only seen it in action at a trade show, and could not remember what it was actually called.

> we (as a society) have got a bunch of poorly patched or corporate controlled WiFi routers

Mobile phone spyware can attack poorly patched or corporate controlled WiFi radio basebands, for 3D imaging of human user behavior.

> heart rate

Laptop demo (2022), https://www.intel.com/content/www/us/en/research/respiration... | https://community.intel.com/t5/Blogs/Tech-Innovation/Client/...

  Intel Labs introduces.. respiration sensing via Wi-Fi.

You mean the Matrix wasn't a technical blueprint for humanity.

Am so confused.

As someone that works closely with WiFi data and given their very low error (< 0.5 BMP MAE) I'd love to see them address a few key points:

- Whether train/test splits were participant-wise to avoid data leakage.

- How the system performs at elevated or highly variable heart rates.

- Results from "placebo" or empty-room baselines to rule out false positives, typically done with bags of rice/water (used to simulate mass).

1. the train test in here was leaky, but in our current iteration of the work we do 10 fold train / test without leakage 2. There was no different in performance at higher HR values, the rpi data contained people running in place and our performance on that was as good as laying down 3. a simple presence detection model would solve that and also the algorithm already covers this

> Now, the researchers are working on further research to extend their technique to detect breathing [...]

Impressive from a technical standpoint, but super scary from a privacy standpoint. Surely this must allow them to detect and differentiate between plosives, which is probably enough to infer what's being talked about.

I'll just quit breathin

See

https://www.nature.com/articles/s41598-024-77683-1

That kind of module can be really cheap

https://www.waveshare.com/hmmd-mmwave-sensor.htm

and is starting to replace Passive IR sensors

https://en.wikipedia.org/wiki/Passive_infrared_sensor

I can imagine one of these on the ceiling above your bed being an ideal sleep monitoring system.

Nobody:

Google: serves you Aspirin ads when they notice you are having a heart attack

At least it's not tomb stones...

I do it using MMWave sensor, 60Ghz one. Want to have more of them but installation is a pain as these need to be mounted on ceiling so WiFi based sensor would be awesome!

Do you have a writeup about this somewhere? I'd love to know more.

You can buy them on Aliexpress for $5. YouTube and a cursory google search will give you many many options to choose from for examples and tutorials.

There are a lot of radar modules out there in the wild.

But not all of them are good for doing stuff like this.

You need full raw I/Q and DAC access to sweep the frequency.

don't get the $5 ones, they are probably just presence detector or at best distance detector and probably work on 24Ghz. Get the 60Ghz for breathing, heart rate, posture etc.

"Low cost mmWave 60GHz radar sensor for advanced sensing" (2025), 50 comments, https://news.ycombinator.com/item?id=44665982

"Inside a $1 radar motion sensor" (2024), 100 comments, https://news.ycombinator.com/item?id=40834349

"mmWave radar, you won't see it coming" (2022), 180 comments, https://news.ycombinator.com/item?id=30172647

"What Is mmWave Radar?: Everything You Need to Know About FMCW" (2022), 30 comments, https://news.ycombinator.com/item?id=35312351

Unfortunately no. But fortunately, it isn't something new I have built. I use a Seed Studio sensor MR60BHA2 which has an ESP32 which sends the data to Home Assistant through ESPHome. Once it is in Home Assistant you can do automations and notifications. I mostly use it for elderly care. I have another DFRobot C1001 sensor but waiting for ESPHome to add support for it. It has fall detection also which is why I am planning to replace it. They are fairly accurate; ~90%; has been my experience. They work better when mounted on ceiling and have a cone like coverage.

Tell more about your setup!

Infineon 60GHz IoT FMCW radar modules have all datasheets published. That's super rare for Infineon - usually they are the worst NDA-hell on earth.

Chinese vendors sell uC+Radar-Module units on Aliexpress for around ~20-30€. They Infineon-based boards are super easy to spot by looking at the Antenna-on-Chip layout.

You can cut off their head (microcontroller) and directly attach your favorite uC onto the SPI bus to talk to them. Or use the existing one.. not overly complicated to reverse engineer the schematic.

Example: MicRadar RA60ATR2

posted some details at https://news.ycombinator.com/item?id=45150761. happy to answer any additional queries you may have.

This would be great for measuring heart rate while asleep because I can stand wearing a watch in bed, and my watch is charging at night as well.

I think it's now fair to be concerned that future MAANG devices will use passive RF data mapping, triangulation, and harvesting to scan you, your environment, and others around you.

The future of individual freedoms can only be assured with open source software and hardware not beholden to the unbounded, extractive fetishes of governments and corporations.

I wonder, if this would work with bluetooth, too. Would be nice to hack e.g. the new, cheaper version Pebble watch to measure heart-rate this way. I mean, possibly this could even be superimposed on the regular BT-connection signals. I presume open firmware would enable these sort of things.

So we can expect that comcast will soon be selling per-household sexual activity rate data to advertisers?

I think soon it will be time to seriously consider eliminating use of Wifi in some private places and going back to speed and reliability of copper wires. WiFi is like basically illuminating an area in light that can pass through walls.

If speed and reliability is needed, or desirable, you've already been doing this. My TV boxes have always been wired, because wifi is silly for (relatively) high bandwidth at fixed locations, given that wires in the wall have either been there or reasonable to add.

Some places, adding wires is expensive and given that wifi has improved over the years, it might not be worth the cost of adding wires.

I think it's safe to say that most smart TVs are wireless and will stay that way. Personally, I have no problem streaming 4K content to my TV over my wifi. Adding wires where they're not needed is what's silly.

Instantly visualises social media companies monitoring individual heart rates and heart-rate social graphs and that becoming an input into their algorithm ... scary shit.

There are products already that do this: https://www.originwirelessai.com/

So how long until my ISP starts selling McDonald's data on how my heart rate reacts to their new commercials that my ISP got based on wifi signals?

Its a good effort but very pedestrian and a very low hanging fruit. Its just another academia paper that will be published.

https://doi.org/10.1109/GLOBECOM38437.2019.9014297 https://doi.org/10.1109/CCNC.2018.8319181 https://dl.acm.org/doi/abs/10.1145/3286978.3287003 ..... many more.

I'd say this is far more interesting, does not use ML and credits the tech stacks that it leverages . https://people.csail.mit.edu/davidam/docs/WiMic_final.pdf

there’s always a cost to the organ being read, will this one day become a way to monitor a crowd for individuals of suspicious activity? scary tech, eventually along this technological trajectory the computer effectively reads your mind by combining biometrics with user profile data and large models, even though it will just be a prediction, a very informed prediction

This would be great to be able to log and monitor heart rate data while sleeping without needing to wear a wearable.

There are already radar devices, such as mmWave, that can do this. Instruction videos can be found on youtube.

New polygraph just dropped.

I'm guessing with a polygraph: the obvious, cumbersome equipment is to make the subject uncomfortable and aware of the measuring, to make them more likely to break, or have a harder time controlling their body.

Bros at UCSC must be getting some good grants from the US military. I can already imagine the next gen of public-wifi driven drone strikes

I guess that means Germany did nothing wrong (when it banned public WiFi).

Isn't it the other way around? Germany actually has it made easier to operate a public wifi by limiting the liability on the side of the wifi provider with their mid 2010s legislation.

Famously it was illegal to operate public wifi in Germany until 2017.

Was it really illegal or was it that as the operator of the Wifi you could be held liable. There's a difference.

seeing a theme here

https://news.ycombinator.com/item?id=45121617

with this level of accuracy and that sword missile with no warhead they can drone strike you in a cafe with disturbing the other patrons

Guys, they can just ask social media Corp A where you are. They don't need no fancy tech here.

Not even, your SIM in constantly pinging multiple towers and triangulating you

slight quibble: That triangulates your phone. Social media (unless you're letting LLMs talk for your) is triangulating _you_.

I'm not certain of the distinction nor that the platforms are triangulating me and not my phone. Especially if you don't directly provide information about what you're doing.

And that 99% or social media users have their phone on them at all times.

If you're trying to targe tsomeone with a deadly strike, just knowing their phone is in a location is not comparable to knowing they just posted something on social media.

Sure, you can attribute a good chance of success to the movement of the phone equating a strike on the person, but it's still _just a phone_ that you're triangulating.

I find it unlikely that people a government would want to kill by drone strike would be posting about their wherabouts on social media and at the same time obfuscating their location by having their phone move without them (by someone ok with being hit by a drone strike?).

Or we're speaking about striking civilians posting on social media - where I'm not sure drone strikes are very cost effective or pertinent.

My understanding is that drone strikes aren't a thing done because you just got a hit on social media of a precise location, but more of a somewhat long investigation into the activity and identity of the target, their habits and movements (both to confirm their value and maximise sucess) - and then a calculated drone strike that both maximizes sucess and minimizes collateral.

Of course Israel does not do this and is more into the "paint a bullseye around the victim" kind of doctrine, but that's outside the scope of this discussion.

Just think about it, folks.

We are now in an era where we all need to learn how to regulate and modulate our own heartbeats.

Will we at some point have any rights over our biorhythmic signatures?

If not, then I will have to learn how to apply a modulation to my own internal oscillations, such that the algorithm is gonna have to use quantum power to decrypt how I'm feeling.

WiFi Sensing shipped in Comcast routers, Intel laptops and Qualcomm phones, https://news.ycombinator.com/item?id=44426726#44427986

It's an excellent time to buy your own device for wifi broadcasting and disable any ISP provided broadcasting (or maybe put it in a faraday cage?) - it's relatively simple to set up with off the shelf components though less technically minded people may struggle with it. There's still a pretty robust market of options and the devices have gotten pretty feature rich with things like mesh networking support being pretty standard.

>though less technically minded people may struggle with it

This is the funniest thing I've read so far today. BOTN

I more meant - you might need to help elderly relatively set it up. There are plenty of wifi routers you can order that basically just plug in out of the box - the bigger issue is educating people that they need the tech and then making sure they can handle the cable connections. I tend to work with some very non-technically minded people so my bar is so so low.

Oh! I wish you lived near Charlottesville, Virginia, where I live. I am a 77-year-old retired neurosurgical anesthesiologist. My technical aptitude is SO low that I dare not exchange my obsolete 10-year-old Comcast WiFi router for the current model that I can "basically just plug in out of the box," even though it's billed as being at least 5x faster than mine, because I don't believe their constant emails that the new one they'll send me is simple to set up. Far more likely than not I'll end up with NO WiFi and have to pay for a technician to come and do it.

What else can it measure?

Voice recording should not be an issue?

They did this at MIT like 12 years ago.

Thanks, now I need to build a faraday cage around my chest to stop the CIA from polygraphing me at range.

I searched directly for Faraday through the comments. Waiting forward for the apparel company that builds this.

And we've been laughing all this time at tinfoil hat types..

Find your target by heartbeat. Fly to heartbeat. End heartbeat.

Wake me up when it can find me in the crowd.

Someone point this at Trump and report back

surveillance state intensifies

WiFi equipment can see your heart beating, but don't worry, it cannot possibly have any harmful effects on human physiology.

What? A camera can see you but cannot impact your physiology unless thrown at you.

Or swallowed :p

Except for the few you’re meant to

The most selfies I've ever taken in a weekend.

I prefer my wavefunction non-collapsed.

A camera detects light. Light can certainly be dangerous to you.

How is that relevant? The camera isn’t blasting you with harmful light.

To add to the comment on cameras: https://www.youtube.com/watch?v=e9ASH8IBJ2U

A sonogram can see your heart beating too, but no one thinks sonograms are dangerous(because they are not).

Unsolicited remote sonograms are stopped by walls, floors, ceilings and doors, unlike wireless radio networks.

For now

A concrete wall stops wifi pretty well.

How thick a concrete wall is needed to stop wifi? Or does the concrete wall contain fine wire mesh?

If by "fine" you mean minimum ~10mm rebar then yes

Have you never walked into a building an lost cell reception?

Found a table with attenuation by frequency and building material, e.g. low-emission glass can block more than concrete, https://www.signalbooster.com/blogs/news/how-much-which-buil...

                        800Mhz     1900Mhz
  1/2" Drywall          2.03 dB    2.43 dB
  Venetian Plaster      7.91 dB    16.22 dB
  6" Concrete Wall      10.11 dB   19.41 dB
  Glass Window          4.35 dB    4.38 dB
  Low Emission Glass    33.8 dB    33.8 dB
  Brick                 7.57 dB    14.66 dB
  Solid Wooden Door     6.11 dB    12.33 dB

Sound can certainly be dangerous to you.

So can water. That doesn't make it inherently dangerous in all amounts.

Ultrasound can be used to blast tumours or break kidney stones. And according to Wikipedia there seems to be a really weird correlation between having an ultrasound and being lefthanded. But that sounds almost too ridiculous to be true.

I have a superficial radial artery. You can take my pulse just by looking at the shadow on my wrist moving in the right lighting. Does this have "harmful effects" on my physiology?

As far as we know, it really doesn't, at least not at the energy levels used in practice. Blasting 2.4GHz at the same energy levels as a microwave oven would cook your flesh if you were sufficiently close to the emitter. But that doesn't happen.

you can get RF burns from VHF/UHF/microwave frequencies with milliwatts if you somehow short the transmission line across yourself, even though the actual voltage and amperage going across your skin is practically infinitesimal. the amount of contact - if any - needed decreases with the RF power. wifi is "legal" up to 1W EIRP, which means a unity gain antenna capable device can output 1000mW at the terminal.

the FCC "considers 50 watts to be the lowest power above which radiation must be considered [...]" for radio transmitters. in 1996.

further:

> Conversely, lower frequencies penetrate deeper; at 5.8 GHz (3.2 mm) the depth most of the energy is dissipated in the first millimeter of the skin; the 2.45 GHz frequency microwaves commonly used in microwave ovens can deliver energy deeper into the tissue; the generally accepted value is 17 mm for muscle tissue.

> The damage can be spread over a large area, when the source is a relatively distant energy radiator, or a very small (though possibly deep) area, when the body comes to a direct contact with the source (e.g. a wire or a connector pin).

note the microwave 2.45GHz part says frequency, not wattage, power, whatever. a home router's antenna's radome (or rubber duck or whatever) touching your arm will penetrate it quite far.

anyhow i've gotten RF burns before, just to see if it was BS or not, at real low wattage (around 1W at the terminal) and it leaves a discolored mark on your skin in a straight line between the contact points and feels like you got a small burn there. The frequency i "burned" myself with was ~145MHz.

This is all to say "it doesn't matter if it's ionizing, it still heats things up."

ETA:

> Frequencies considered especially dangerous occur where the human body can become resonant, at 35 MHz, 70 MHz, 80-100 MHz, 400 MHz, and 1 GHz

Please don't post sneering comments like this on HN. The point itself may be valid, and raises a question worth discussing, but when it's phrased like this it crosses into shallow dismissal and flamebait territory, and is against the HN guidelines. We've had to ask you to observe the guidelines in just the past few months. You're a longtime community member and we value the positive contributions you've made over the years, but we need everyone to make the effort to use HN in the intended spirit.

https://news.ycombinator.com/newsguidelines.html

OK, I can do that.

Much appreciated!

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