How does it work?In the UK there is an alternating mains current at a nominal average value of 50 Hz per second. However, there are micro-fluctuations in the rate of alternation that change unpredictably second by second. The mains current is fluctuating and at any moment it could be anywhere on the scale of 49 Hz to 51 Hz per second. Because the National Grid regulates and standardizes the distribution of electricity, the exact same buzz can be heard at the exact same moment nationwide from Land's End to John o' Groats. Whether the frequency is currently 49.6 Hz or 50.3 Hz, it will be exactly the same reading from a neon light in Glasgow, a fridge in Southampton, and a laptop in London at exactly the same time.
As the secondhand turns around The Hummingbird Clock like a seismograph it draws the line of the UK's fluctuating mains current and this pattern of fluctuation is being recorded and archived every second 24/7. This information can be used to analyse a digital recording extract the fingerprint of the mains’ hum from that recording and correlate that with the clock’s database. Digital recordings almost always have mains hum on them, either because the device was plugged in to the mains or because it inducts it off nearby cables, lights and appliances in a room. The Hummingbird Clock is able to automatically match the fingerprint of the mains hum on a given recording with it's database of the buzzing mains, and therefore tell you exactly when the recorded event occurred or if the recording itself has been tampered with and edited. The archiving of the mains power supply begins on the 7th July 2016 so we can only analyse recorded events made from this date forward.