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- Could the CIA really track your heartbeat from kilometers away? On April 3rd, 2026, Iranian forces shot down an American fighter plane just over Isfahan. Inside were a pilot and a weapon system officer, and both ejected successfully. The US forces located the pilot quickly and rescued him only seven hours after the crash, but they couldn't rescue the weapon system officer. He landed elsewhere deep within hostile territory. And, worst of all, he was injured. With the Iranian forces on his tail, the officer needed to hide quickly, so he disappeared into the mountains. to rescue an aviator buried deep behind enemy lines.
- Fortunately, the officer had a rescue beacon that could signal his location to the US. The problem was that he not only had to step out of his hiding spot to transmit the signal, Iran could potentially intercept it and get to him first. So he could only use the beacon sparingly. With enemy forces getting closer every hour, how is the US going to pinpoint his location in the middle of a desert. - [Gregor] A blind sweep of the entire area could take days or even weeks, but, surprisingly, just 40 hours after the crash, the US announced the officer was rescued.
- Still invisible to the enemy, but not to the CIA. - So how did they do it? Well, according to a New York Post article, the CIA deployed a futuristic device to rescue him. Reportedly they were able to detect the magnetic field produced by his heartbeat from kilometers away. Such a device would have to overcome the magnetic signatures from other soldiers, vehicles, and animals in the region, let alone Earth's magnetic field. It's like listening for a murmur in a crowd. So the technology was appropriately called Ghost Murmur. Immediately this kicked off a media frenzy.
- Ghost Murmur. - This is science fiction. - Ghost Murmur. - Did you hear about what the CIA tech that they have called the Ghost Murmur. - Called the Ghost Murmur. - All of this sounds too good to be true, and there seemed to be no other sources beyond this New York Post article. So we dug deep to find out whether this supposed technology really exists and what its limits are. - I very rarely believe things I read in the New York Post. - Okay. - I find it extremely difficult to believe. - Many of these researchers in the NV diamond area, are having to sign NDAs.
- The fact that the CIA is involved in leveraging technologies consistent with their mission and their charter. - So is Ghost Murmur fact or fiction? There are two lines in this New York Post article that hint at what this device can be. First, normally this signal is so weak that it can only be measured in a hospital setting with sensors pressed nearly against the chest, the source said. But advances in a field known as quantum magnetometry, specifically sensors built around microscopic defects in synthetic diamonds, have apparently made it possible to detect these signals at dramatically greater distances.
We're gonna break this down bit by bit. First, does the heart actually create detectable magnetic fields? Second, what are these synthetic diamonds that could potentially detect them? And third, is it all possible at these distances? Let's start with a heart. Now, if you type heart magnetic field into Google Images, you will get a bunch of questionable-looking graphs. So is it a real thing? Well, whenever current flows through a conductor, it generates a magnetic field around it. And since our bodies run on electrical impulses traveling through neurons, our tissues and organs generate faint magnetic signals.
But because the heart muscles fire in a coordinated way, the magnetic field they produce is the strongest in the body. It's around 50 to 100 pico Teslas, 10 to 100 times more than the next strongest field produced by the brain. But even then, this is still a million times weaker than Earth's magnetic field. So it's no surprise that we only detected the magnetic field of the heart in 1963. It had to be done in a remote field away from the magnetic noise produced by lab equipment, elevators, and cars. And the setup had to be incredibly still.
Even the slightest vibration of the detector would corrupt the measurement, not something that could work on a helicopter or a military drone. But, pretty soon, magnetometers got better. By the 1970s, we got superconducting quantum interference devices, or SQUIDs. These magnetometers were incredibly sensitive, detecting fields as weak as a few femto Tesla. To no surprise, the US military quickly strapped these SQUIDs to planes and helicopters, and they tried to use them to detect large magnetic signatures like submarines in the ocean. But the project never really picked up.
Nonetheless, SQUIDs also made it easier to detect the heart's magnetic field, but with a key caveat. - They typically need to be operated under a very tightly controlled conditions, often inside of shielded rooms. They can't handle large dynamic range of background fields and electromagnetic interference. - Future magnetometers offered solutions, but they also had their own drawbacks. There were always issues with either shielding or sensitivity or dynamic range that made them impractical for detecting heartbeats out in the field.
Until the 1990s when physicists started looking into diamonds that might eventually be able to sense magnetic fields while potentially getting around the drawbacks. - These new quantum magnetometers work at room temperature operation, and that's what's really exciting about them. They're also a solid state sensor, which, you know, can be very practical for some applications and can be made into like a more robust kind of sensor. - These are the diamonds mentioned in the New York Post article. So how do they work?
Now, the overall coverage of the story is actually very interesting because this tech is supposedly classified. There's a lot of uncertainty about whether what's being reported is actually real. And depending on which outlet you see first, you might arrive at completely different conclusions. For example, if you saw this headline first, you might be really impressed with the technology, but this one you'd be a bit more skeptical, and the last one might not even make you care about the tech. So three headlines, three completely different conclusions, and that's where today's sponsor Ground News comes in. They're a website and an app designed to make reading the news easier and more data-driven.
Each day they round up stories from thousands of outlets all around the world and give you a visual breakdown of the story, including its political leaning, factuality rating, and even ownership, all backed by ratings from three independent media-monitoring organizations. In case of this Ghost Murmur story, you can see that it's been reported on by 65 sources, but the coverage is pretty lopsided. So if you only get your news from right-leaning outlets, there's a chance you've seen the story. But if you only get it from the left, there's a chance you haven't. And below that, you can also see the factuality rating and the ownerships of the sources.
They also have this blind spot feature, which highlights stories like the Ghosts Murmur one that were under reported on by either side of the political spectrum. Staying up to date and well-informed with accurate information has almost become a full-time job. And that's where Ground News's approach is so valuable. They make reading the news more digestible and accessible, and you can see all of the information within moments, not hours. So if you, like us at Veritasium, care about getting to the truth, you can go to ground.news/ve or scan this QR code
and our link will get you 40% off their vantage plan. So I wanna thank Ground News for sponsoring this part of the video, and now let's go figure out how those diamonds actually detect magnetic fields. Well, for something to function as a magnetometer, it needs to respond to a magnetic field in a way that we can detect. Now, a pure diamond is just an ordered lattice of carbon atoms, so it doesn't react to magnetic fields in a meaningful way. But this changes when you start adding defects to the lattice. You can replace one of the carbon atoms in the lattice with, say, a nitrogen. And if you remove one of the carbons next to it completely, well, that creates a vacancy.
This defect is called a nitrogen vacancy or an NV center. And these NV centers become particularly useful when they trap two unpaired electrons. That's because electrons have this intrinsic property called spin. A simple and flawed analogy is that spin is kind of like a tiny bar magnet that gives electrons their own magnetic signature and it can point either up or down. So when an electron is exposed to an external magnetic field, this magnetic signature will either align itself with the field or against it. Also note that particles that have no net spin will not respond to an external magnetic field.
Now, the two trapped electrons can arrange their spins in the following way. They could both point up, which would give you a spin magnetic number of 1. They could both point down for a quantum number of -1, or they could point in opposite directions for a quantum number of 0. We'll denote this spin magnetic quantum number with ms, and it essentially acts as a bar magnet for the whole NV center. And just like for individual electrons, this bar magnet is also sensitive to external magnetic fields. So now that we've created a diamond
that responds to magnetic fields, the challenge is, how do we measure this response to detect a heartbeat? Okay, so I reached out to experts to try and figure this out, but basically out of the 20 or so emails that I sent, I only got a few responses, but then I got an impromptu call from one of these experts who said that many of these researchers in the NV diamond area are having to sign NDAs. This is getting a lot more interesting. But with how secretive everyone was being, I had to use publicly available research. And I think the key idea is to figure out how diamonds respond to magnetic fields, you have to use light.
When you shine light at an atom, the atom can either absorb the light or ignore it. An absorbed photon of light will excite an electron within the atom to a higher energy level. You can think of these energy levels as discrete platforms that the electrons can jump between, just like in a video game. All atoms of the same element, for example, carbon, have the same energy levels when the atoms are far enough apart. But when you bring them together, like inside a diamond lattice, their energy levels shift.
They come together to form a series of closely spaced energy levels or an energy band. Now, an electron will only ever absorb a photon if the photon has enough energy to move the electron across the gap to a higher band. This gap between the last electron occupied band and the first empty band above it is called the band gap. In a pure diamond, it's big. It's around 5.5 electron volts, which means that only ultraviolet photons have enough energy to excite the electrons. All lower energy light, including visible light, will mostly be ignored by the diamond and just pass through.
This is why a perfect pure diamond is transparent. It doesn't absorb any of the light, but if you start adding defects, they disrupt that organized lattice. The defects unlock different energy levels. Secret platforms within this band gap for nearby electrons to jump to. A boron defect, for example, creates a low energy level at only 0.37 electron volts. This is a platform that electrons can jump to by absorbing infrared or red light. And with enough boron defects, a significant amount of red light gets absorbed this way.
The rest of the visible spectrum mostly makes it through. So without this red, the diamond appears blue. Similarly, a nitrogen vacancy defect unlocks other secret platforms. And these can help us detect how the NV center responds to a magnetic field. At first glance, it looks like the nitrogen vacancy generates a few unique levels, and these are exclusive to the two unpaired electrons trapped within the defect. But if you look closer at, for example, the lowest level, you'll notice that it actually contains three closely spaced but separate energy levels. The second and third levels are actually at the same height, but will draw them separately. And the fact that there are three isn't a coincidence.
Remember, the NV center can adopt one of three ms numbers, 0, -1, or 1, depending on how the spins of the two electrons inside are arranged. If you think of the two spins as bar magnets, the most relaxed, lowest energy way for them to sit is this, one pointing up and the other down. This is analogous to the ms = 0 state, which is why it has the lowest energy. Forcing both magnets to point down together or up together, like the ms = 1 or -1 states requires more energy. They oppose you. So these two states are at an equal, slightly higher energy sub level. These differences are tiny. Jumping from the 0 to the +/-1 levels requires only a small amount of energy.
A microwave photon of 10.4 centimeters will be enough. Now, these secret energy platforms of NV centers were mapped out by the '90s. But for a long time, no one thought to use them as magnetometers. - There was a decade before the light bulb went on for a bunch of us to think about them as sensors. It takes a mindset switch to think differently. And once you do, you realize, "Oh my goodness, this could be useful." - So let's apply a magnetic field to this diamond and see what happens. If we slowly turn up the field strength, you'll see that the +1 and -1 levels are starting to shift. To understand why, we can use a compass needle as an analogy.
Naturally, a compass needle will align itself with the magnetic field of the Earth. And this is the lowest energy relaxed state that the needle can be in. And it's analogous to the behavior of the system in the ms = -1 state, which is why its energy level drops slightly. But if ms = 1, the system flips. This would be like taking an external magnet and applying it to this compass needle, flipping it 180 degrees. And then if I'm careful in retracting this magnet, I can actually get the needle to stay in this place. And this is the highest energy this needle can have sitting in this unstable position.
Now if I tap it, it will actually go back. It's possible, but it's a higher energy state. So the ms = 1 level slightly rises. And if ms = 0, it doesn't react to the field, which is why this level hasn't changed. Now, if you keep turning up the magnetic field strength, you'll notice that the levels get further and further apart. This phenomenon is called Zeeman splitting. It's described by a simple formula that gives you a direct link between the energy split and the magnetic field strength. So in the presence of a periodic magnetic field like that generated by the heart, we would theoretically see a rhythmic separation
of these lines. And these two energy levels absorb light at two different microwave wavelengths, which change depending on the strength of the field. So what we can actually measure is which microwave wavelengths the diamond is absorbing. When there's no magnetic field, the levels are fused and produce a single absorption line at the wavelength of 10.4 centimeters. But when there's an external magnetic field, they produce two separate absorption lines. Now, we've simplified it a bit, but by measuring how spaced apart these lines are, you get the field strength. This is how an NV diamond magnetometer works.
Was the diamond magnetometer ever used to detect a heartbeat? - So what has been done for sure is, you know, for certain is detection of magnetic fields generated by neurons. Yeah, I mean, which is to some extent connected to the heartbeat question. Neuron activity, to my knowledge, has been first seen in 2015. - Okay, well, that's, wow, that's impressive. So could it pick up a heartbeat from kilometers away? Well, in 2022, researchers were able to pick up the magnetic field of a rat's heart, but it was done using a thoracotomy, which means the rat's chest was open
and the diamond was less than two millimeters away from the heart. Okay, but the human heart produces a stronger magnetic field. And the tech, the CIA might have deployed, could be decades ahead of what is publicly known. You're former CIA operations officer and you've worked in the Middle East, right? So what was your first reaction to this news? - Well, the fact that the CIA's involved in leveraging technology is consistent with their mission and their charter. But I defer to smarter people in engineering and science like yourself to figure out the exact technique that might be used.
But the processes, of course, are consistent for what we've done. - We can't say for sure whether the CIA has this tech, but we can use physics to estimate how sensitive it would need to be. Well, the strength of a magnetic field falls off with the cube of the distance from the source. So if the magnetic field of the heart when measured at the chest is 50 pico Tesla, or 5 times 10 to the -11 Tesla, well, then just 100 meters away, this falls off by a factor of a billion to 5 times 10 to the -20 Tesla. And at 50 to 100 kilometers, this could drop to as little as 10 to the -30 Tesla.
- The most sensitive measurement ever made at the frequencies that the human heartbeat work at is at the 10 to the -15 Tesla level. And that's in a shielded room. So you'd need a system that is 15 orders of magnitude more sensitive than the superconducting quantum interference devices and 18 orders of magnitude more sensitive than diamond NV sensors. - 18 orders of magnitude is a lot, sounds quite unfeasible. - It's not like the hills of Iran are devoid of animal life.
They also have heartbeats and possibly larger hearts than humans. - There's also the magnetic field of the drone or the helicopter the device might be mounted on. And, finally, there's the fact that a magnetic field of 10 to the -30 Tesla is weaker than a magnetic field an electron will give you a meter away. - The New York Post is notoriously a very good place for amusing fiction. - On the day before we saw this article, we also saw an article about how they had a technology where it was a beeper. and that was one way that they were able to detect him. And these are things that we know about already.
We also know that there may well have been other intelligence methods used, but this isn't really necessary. - And then that brings you to the point of like, why would they make this up? - I think New York Post is known to print a lot of stuff. - I'm not a real fan of the credibility of the press to report things, having seen reality and then seeing what the press reports. - How about deception stories and like false narratives published by not only the CIA, but other agencies? Is this often the case?
- If you look historically, the idea of fooling your enemy, particularly when you have some vulnerability to protect, goes back thousands of years. - During World War II, German bombers frequently attacked Britain at night. And to retaliate, the British would fly up to intercept and somehow kept finding these bombers in the dark and would attack them. Now, UK officials told the press that the pilots were able to do this because they ate a lot of carrots, which was improving their vision at night. But some experts believe that this was actually a cover story meant to distract the Germans
from the fact the British installed radars on their planes. - Is that where the idea that carrots give you good eyesight comes from? - I think so. I think this is the original, yeah, the original myth. - That is crazy. - Yeah. - But, okay, there's one thing that still bothers me. If this is likely fake, then why is everyone saying no comment and declining to talk? There must be something here, you know? - Well, these NV centers and diamonds are also used for quantum computing. But the more interesting, probably confidential way they could be used is as navigation devices.
The Earth's magnetic field creates a unique pattern all across the globe. - Then to place an object into this map, and if you know all of these perturbations and in homogeneities, you can infer where you are without having any GPS reception anymore. - With the rise of GPS spoofing and jamming over the last couple of years, that could be incredibly powerful. So NV magnetometers do exist with these synthetic diamonds, and they do have potential military applications. It's just that detecting heartbeats kilometers away probably isn't one of them. I wanna give a shout-out to a great Scientific American article on this story by Deni Béchard that initially expressed skepticism in Ghost Murmur as a potential technology.
It's a great read and you check it out.
