5.9M views · Dec 20, 2021 · 5:31 · 3 HN recommenders · 8 mentions · discussed 2022–2025
Tom Scott explains Electrical Network Frequency analysis, where hum from the power grid in a recording is matched against grid logs to date and place it. He talks to a researcher and sets them a challenge.
Why Hacker News points people here: The go-to short, accessible explainer for mains hum forensics, linked whenever recording authenticity or timestamps come up.
“less detailed but pretty accessible video [1] explaining how mains hum forensics work”HN comment, 2023
“background noise giving the location of a recording due to power line frequencies being subtly different I recommend it.”
Background power-line frequency reveals recording location and time
If you haven't already seen tom Scott's video on background noise giving the location of a recording due to power line frequencies being subtly different I recommend it. this video
“less detailed but pretty accessible video [1] explaining how mains hum forensics work”
Accessible explanation of how mains hum forensics work
If this is interesting to you or your kids, here's a less detailed but pretty accessible video [1] explaining how mains hum forensics work, complete with British accent. [1] this video
“I really enjoy Tom Scott. Everything he puts out is wonderfully concise.”
Concise video on the same subject
A video on the same subject: this video I really enjoy Tom Scott. Everything he puts out is wonderfully concise.
“There are companies that already provide this kind of service”
Points to existing companies offering similar service
There are companies that already provide this kind of service so it might be interesting for you to combine efforts: this video
“you can use background noise emitted by electricity to prove that a recording has been taken at a certain time and place.”
Background electrical noise can prove when and where a recording was made
According to a Tom Scott's video[1], you can use background noise emitted by electricity to prove that a recording has been taken at a certain time and place. [1]: this video
“Tom Scott made a video about the idea”
Video about the idea behind commenter's own project
I'm writing a open-source library ( link ) and a webapp ( link ) that detects the Utility Grid noise emitted by electrical devices (A/C, motors, appliances ...) from Video/Audio recording. It then tries to date the recording by matching it to historical data. The signal processing part is getting decent. I'm still trying to collect more reference signals in RU, UK, China and Japan. Tom Scott made a video about the idea: this video
“there was an interesting video by Tom Scott where investigators used the electrical hum background noise to determine when something was recorded.”
Electrical hum used to determine when something was recorded
Probably not practical but there was an interesting video by Tom Scott where investigators used the electrical hum background noise to determine when something was recorded. Maybe there is a way to audio record something to prove location. this video
“Reminds me of the 'mains hum' technique that was used to identify videos.”
Mains hum technique for identifying videos
Reminds me of the 'mains hum' technique that was used to identify videos. Can also be done with light. this video link
