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> 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.


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.


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.


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?


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.


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?




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