CIA used "long-range quantum magnetometry" called "Ghost Murmur" in Iran | Hacker News Reader

CIA used "long-range quantum magnetometry" called "Ghost Murmur" in Iran

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36 pointsbhouston36 comments

https://www.cia.gov/readingroom/docs/CIA-RDP96-00787R0007000...

Right, magnetoencephalography has been known for some time. The ending of that paper is wild though with the weird ESP paranormal stuff, then I remembered that this is a CIA paper from the 70s...

It seems that the majority of the skepticism comes from the classical understanding of magnetism and magnetic fields.

It seems incredulous that you can detect the magnetic dipole of a heartbeat at distance because the magnetic field generated by a heart is essentially nonexistent. However, there /is/ a measurable effect from the magnetic vector potential even if the magnetic field is or is essentially 0. This seems counterintuitive, but has been experimentally verified [0, 1].

There are a myriad of quantum magnetometers with the main categories of superconducting (SQUID), atomic, and nitrogen-vacancy (NV) [2]. Superconducting magnetometers require cryogenics, so we can immediately discount its usage. Nitrogen-vacancy magnetometers can detect high frequency magnetic fields, which a heartbeat is not, and are less sensitive than atomic magnetometers. Therefore, NV magnetometers can be disregarded.

Now, for atomic magnetometers. Optically pumped atomic magnetometers (OPAM). These are highly portable and extremely sensitive (fT/√Hz), with some OPAMs approaching the quantum noise limit [3]. Moreover, the detection of a magnetic vector potential is possible [4].

Another type of atomic magnetometer is the Spin Exchange Relaxation Free (SERF) magnetometer. SERFs are even more sensitive than standard OPAMs (aT/√Hz). So, likely, some form of atomic magnetometer is being used.

Nonetheless, they most likely used a mixture of other methods to reduce the search area.

[0] https://www.feynmanlectures.caltech.edu/II_15.html#Ch15-S5

[1] https://www.youtube.com/watch?v=XKSjCOKDtpk

[2] https://www.nist.gov/quantum-information-science/sensors-mag...

[3] https://pubs.aip.org/aip/apl/article-abstract/89/21/214106/3...

[4] https://pubs.aip.org/aip/adv/article/13/2/025127/2877320/Dif...

Just a few numbers and even one equation, sorry: The heart is a magnetic dipole, and the field of a magnetic dipole decays as 1/r³. Therefore, if it can be detected at a distance of 5 cm, then at a distance of 50 kilometers it will be (5,000,000 cm / 5 cm)³ = 10¹⁸ times weaker. A quintillion times smaller. I think the discussion of signal-to-noise ratio is a bit... uh... misleading.

I don't think it's too misleading. There have been atomic-optical magnetometers developed with sensitivity of 10s of fT/√Hz, so approaching the quantum noise limit. The issue seems to be SNR to a certain extent.

In an ideal situation, such as being isolated in a desert, detecting the heart within meters is achievable, within a kilometer plausible, within 10s of kilometers implausible.

It's also a matter of just getting plausible detection. If you get a reading that might be a heart, you can move closer. Being able to move the detector provides much better search capabilities.

How do you distinguish a heart of a human and the heart of a rat with at that distance and that noise level?

I've used https://en.wikipedia.org/wiki/Lock-in_amplifier and in ideal conditions you get a 10^6 amplification, when you send a very clean signal and measure how it bounce.

My expert opinion is that 10^18 is im-facking-possible.

> How do you distinguish a heart of a human and the heart of a rat with at that distance and that noise level?

A rat has a resting heart rate above 200bpm. The only thing similar to a human heart beat would be of a dog, pig, goat, or sheep.

> The secret nature of Ghost Murmur was “basically why everyone’s been so cagey about how [the airman] was actually found,” the first source said.

Or an excellent fictional coverup for a failed Isfahan raid, not that such a thing would ever be considered by rational officers.

Yeah, this Ghost Murmur thing doesn't seem to hold water. But I figured I'd post it anyways, maybe someone know more than me about this field.

Also, I agreed that there was a failed raid, I tried to post on it yesterday but got no traction:

https://news.ycombinator.com/item?id=47665350

Magnetocardiography is a thing. The NRO has some insane capabilities, so I wouldn’t immediately discredit the idea that a magnetocardiographic scan of a large area is possible.

It’s important to note that the individual was isolated by miles. And that they knew the time and location of the crash to determine the search radius.

It’s also one of the many tools they can use. So they may have used some combination of methods to reduce the search area and to pinpoint the target’s location. To say that they only used magnetocardiography is probably false.

Earth’s geomagnetic noise fluctuations are on the order of nanoteslas (10^-9 T), which is 18 orders of magnitude above the signal they claim to have pulled out.

It’s below the thermal noise floor of any physical measurement system that obeys thermodynamics. You can’t engineer around it because it’s not an instrumentation problem. The signal is smaller than quantum noise limits at that scale. “AI” filtering doesn’t help when there’s no signal to filter. You can’t computationally recover energy that isn’t there.

This is certainly bullshit of the finest, most grassy and odorous caliber.

Background noise is pretty random. A cardiac signal is pretty regular.

Could be like astrophotography. Where you focus long enough that the background noise cancels out.

What if they have a bunch of prerecorded data for the guys heart, then use a lock in amplifier to see if there is a signal in the noise

https://en.wikipedia.org/wiki/Lock-in_amplifier

It could be real. Or it could be a smokescreen for their remote viewing program. But isn’t the most likely explanation that pilots carry a radio/gps device and that’s how rescue found him?

It is. One of the first magnetocardiographs was of my heart, because I happened to be in the basement when my fellow graduate students were looking for a subject (I’m a theorist and wouldn’t be allowed to actually touch anything). They used a SQUID that cancelled out the Earth’s field and its gradient; the sensor was close to my skin but not touching it.

Those loot boxes with identity and payment cards recovered from the broken airstrip may phone home.

I think there is a real chance this is a smokescreen or diversion, but if it is real, then I'm actually kind of shocked that it could ever work. I guess once in a while tech surprises me. I mean, that weak a signal + the inverse square law + everything in the area (living things, static electricity, aircraft systems, geomagnetic)

I mean... wow. That really works? Damn.

It really makes me think that if it's possible to pick up a magnetic signal that weak, what else could be inferred from a signal that weak? Mineral deposits? ship wrecks? Hidden tunnels?

Murmur BS aside - holy shit, they had to abandon two C-130 class planes because they got stuck in the mud? And lost an A-10 Warthog on top of the original F-15?

This looks like a massive fuckup!

The MC-130s, too - that's a variant that can be outfitted with the Metal Gear Solid-style fulton extraction.

It might be the Kojima in me speaking, but if this was a raid on Ishfahan then they might have planned to fulton out the centrifuges from a safe distance: https://en.wikipedia.org/wiki/Fulton_surface-to-air_recovery...

"Many people said Jimmy Carter knew how to fuck up in Iran, but those people never met me because I am the world's greatest expert in fucking up in Iran, and there will be so much fucking up you'll get sick of me fucking up."

The consensus here seems to be it's unlikely to be feasible. Further if it was true why would they reveal it and remove any advantage of it secrecy?

So the question is why make up such a story? Why reveal it through Trump? What else about the story is false? Was this all cover to go into that nuclear facility?

Would they really need all of this equipment and troops to go get one guy? Isn't it usually a couple helos, some tankers, and some air cover?

More than likely this is a cover story for the RQ-180 orbiting At high altitude and using its thermal IR cameras for real time imaging. Remember Trump said something about seeing the pilot move especially His head.

Heh, they even reused the name from “the ghost of Kiev”

Smells like absolute BS to me.

Same.

But perhaps the underlying technology is a superconducting SQUID.

The ability to detect a heartbeat from distance is far fetched though.

So is cm resolution with satellite imagery, but the NRO does have those capabilities.

The photons arriving at the satellite from a ground target aren’t getting weaker due to distance in any way that defeats you, because the sun is illuminating the target and the NRO just needs to collect enough of the reflected photons.

SQUID sensors (the most sensitive magnetometers that exist) require magnetically shielded rooms to record cardiac signals at centimeter range.

They require a shielded room to increase the SNR. SQUID sensors are sensitive enough to record cardiac signals at distance. The issue is SNR.

What they are saying is that they produced a low noise sensor array and managed to increase the SNR through computation. They also stated that it was an ideal environment with no other electrical/magnetic interference.

> They require a shielded room to increase the SNR.

Not anymore. That is exactly the purpose of Darpa Ambient program: https://www.darpa.mil/research/programs/atomic-magnetometer-...

Demo from 2022: https://www.youtube.com/watch?v=VTnIXWCBYTw

AMBIIENT’s goal was biological imaging.. sensors near a body for medical/neuroscience applications. The range being discussed is still on the order of meters at best, not miles.

> AMBIIENT’s goal was biological imaging.. sensors near a body for medical/neuroscience applications.

As with all DARPA projects, there is a civilian use-case and a military use-case.

That demo was at a conference, in a city, surrounded by electronics and RF noise. The fact that it worked at all in that environment is surprising. As the subject got closer to the apparatus, the signal became larger than the background noise. So, I think the distance is limited mostly by background noise. The press release did state that it was an optimal environment for locating their target, i.e., an isolated person with only geomagnetic noise and known signatures of the aircraft.

If background noise was the factor, which it's not, but if it was, the background noise to combat would be the thermal noise floor of any physical conductor at any temperature above absolute zero. But that's not the factor. You're assuming the cardiac field is like a radio signal being transmitted rather than a local field effect. A magnetic dipole doesn't radiate energy outward the way a radio antenna does. It creates a static field that exists in the space around it, and that field geometrically collapses with distance. I ran the numbers on Wolfram Alpha, and at 1 meter from your chest the field is around 100 femtotesla. At 10 meters it's around 100 attotesla. At 5 kilometers it's around 10^-27 tesla.

Oh, but you say that you simply cool the sensor to 0K. Cooling helps, but you're still many orders of magnitude short even at near 0K, and you're doing this in Iranian mountains, not a dilution refrigerator.

You’re calculating based on classical mechanics. The sensors are optical-atomic magnetometers, using quantum mechanics to measure magnetic vector potentials (MVP), which behave differently and can produce seemingly non-local effects (Aharonov–Bohm effect).

> A magnetic dipole doesn't radiate energy outward the way a radio antenna does.

See Section 15-5 of https://www.feynmanlectures.caltech.edu/II_15.html#Ch15-S5

Veritasium has a video on the weirdness of MVP: https://m.youtube.com/watch?v=XKSjCOKDtpk

See https://pubs.aip.org/aip/adv/article/13/2/025127/2877320/Dif... for an experiment measuring MVP with an optical-atomic magnetometer.

> Oh, but you say that you simply cool the sensor to 0K.

These sensors do not require cryogenics and have been developed with sensitivities of 10s of fT/√Hz, so approaching the quantum noise limit.

Essentially, you can think of it as measuring the energy of a magnetic dipole in space instead of measuring a magnetic field.

It's not a SQUID. There is new technology (quantum magnetometry) that measures slight shifts in molecular energy levels inside defects in synthetic diamonds. One of the google/alphabet spinouts from their quantum computing research is commercializing the technology (SandboxAQ).

The have a non contact MCG, like a EKG, but no electrical contacts. They can definitely "see" the heart beating from a few feet away.

SandboxAQ is also developing a navigation version. Put this sensitive magnetometer on a plane. You get very sensitive measurements of the local magnetic field. Once they have a region mapped, you can get exact positioning just from measuring magnetic fields.

You can extrapolate from SandboxAQ and get long range detection of a human heart. I don't know if it's real, but if so it's probably came out of that research effort.

You are correct, it is not based on SQUID. But, I think SQUID is technically a class of quantum magnetometer? Quantum magnetometry is pretty vague, since most high-end magnetometers use some sort of quantum mechanics.

I think the term you're looking for is atomic-optical magnetometer. Someone posted a DARPA project (AMBIIENT), that uses one. What's special about the atomic-optical magnetometer, is that it measures the gradient directly. With SQUID, if you have two SQUIDs in a uniform magnetic field, you can't determine the vector of the field. But, with atomic-optical magnetometry you can.

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