The Tech Blog

Advanced Tech: Ghost Murmur

Posted under Advanced Tech on April 26th, 2026 by Amaldev

You might have seen news a few weeks back about the rescue of a US pilot from Iran. Then came a media post from NewYorkPost about Ghost Murmur, a device that supposedly helped find him by detecting his heartbeat 60km away. There was a lot being said about it. I wanted to see if this was scientifically possible. It’s defense tech, so this will be slightly speculative from my end.

The claim made is that your heart creates a tiny magnetic field when current flows through it. A sensor picks it up and an “AI” software filters the noise and looks for a heartbeat pattern.

I deep-dived into it. There was a base technology that kind of enables it. It’s called Quantum Magnetometry. This was shown with NV centers in diamond. NV means nitrogen-vacancy. In simple terms, one carbon atom in diamond is replaced by nitrogen, and the neighbouring carbon atom is empty. When you shine laser light and apply microwaves, its quantum state changes slightly with the magnetic field around it. By reading that change in light, the diamond can act like a very sensitive magnetic-field probe.

So the probing tech is real. Many research groups work on NV-diamond magnetometry, and heart magnetic signals are also real. But heartbeat magnetic field is a very weak near-field signal. Near the chest, it may be in the picoTesla range, which is already tiny. A picoTesla is one trillionth of a Tesla. For reference, Earth’s magnetic field is usually around 25-65 microtesla.

And once you move away, that signal drops very fast. So I highly doubt they have somehow magically solved the problem that it survived kilometres of air, terrain and Earth’s magnetic field. They claim AI software, but AI can kick in only if the data capture is possible. So detecting one human heartbeat from 60 km away feels extremely unlikely based on public physics. I do think the claim is an overexaggeration from someone either to mislead or oversell.

Realistically it might be a sensor fusion. Maybe like a rescue beacon, GPS burst, thermal imaging and maybe some magnetic sensing all feeding one system.

What do you folks think?

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Tech Explained: BLE vs UWB for Distance Measurement

Posted under Tech Explained, Technology on April 19th, 2026 by Amaldev

Recently I was in a discussion where folks were comparing Bluetooth(BLE) and Ultra WideBand(UWB) for a ranging application. Some were saying the latest BLE 6 will replace UWB for ranging. I do not think it is that simple. Let’s discuss.

I have explained both techs in great detail in older posts, so please refer to it if needed. In short, BLE 6 gets true ranging through Channel Sounding. Instead of guessing distance from RSSI, it compares phase across many 2.4GHz channels, using round-trip time as a secondary check. UWB takes a different path by sending very short pulses across a very wideband(>500 MHz) and measures time of flight very precisely.

Theoretically, Bluetooth Channel Sounding is impressive. The Bluetooth SIG says it is designed for around ±20cm accuracy and can measure out to 150m in the right conditions. In real world, things are slightly different. Silicon Labs testing showed about 0.5m error in clear line of sight, but this can grow to around 5m without line of sight, and even close to 10m with fewer channels.

UWB is still the cleaner tool when distance is the only consideration. UWB typically delivers around 10cm accuracy in line of sight and often maintains sub‑meter accuracy in non line of sight, with practical line of sight ranges up to about 200m. That is why UWB is used in digital car keys and phone-based precision finding. It holds up better when reflections, body blocking, and multipath get ugly.

So my practical advice is: If you already have BLE in wearables, locks, or accessories, BLE6 ranging can be good enough for presence, room entry without adding another radio. If you need consistent sub-meter accuracy in cluttered environments, or you are making decisions based purely on distance, UWB remains the more reliable choice.

BLE 6 chips like Nordic nRF54 and NXP KW47 are just emerging, while UWB parts like Qorvo DW3000 are mature. BLE 6 is new, so combining both, like Apple’s Airtag approach, gives low-power discovery plus precise UWB ranging, if BOM costs allow it. So do consider this next time.

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