It used to be that time was a lot more relative than it is today. With smartphones synced to GPS and network providers’ clocks, we all pretty much have access to an authoritative current time, giving few of us today the wiggle room to explain a tardy arrival at work to an impatient boss by saying our watch is running slow.
Even when that excuse was plausible, it was a bit weak, since almost every telephone system had some sort of time service. The correct time was but a phone call away, announced at first by live operators then later by machines called speaking clocks. Most of these services had been phased out long ago, but one, the speaking clock service in Australia, sounded for the last time at the end of September.
While the decommissioned machine was just another beige box living in a telco rack, the speaking clocks that preceded it were wonderfully complex electromechanical devices, and perfect fodder for a Retrotechtacular deep-dive. Here’s a look at the Australian speaking clock known as “George” and why speaking clocks were once the highest of technology.
Continue reading “Retrotechtacular: The Speaking Clock Goes Silent”
[Urpo Lankinen] has a father who is a huge movie buff, and once you care deeply about something it begins appearing everywhere you look. While driving on a back-country road one day, [Urpo]’s dad noticed that the shadows of the trees on the road looked like an optical film soundtrack, so it was up to the son to make it happen.
Early sound-on-film technologies like the RCA Photophone, and Movietone recorded audio onto the film stock with a variable area exposure. This exposure corresponds to the waveform of the audio signal. [Urpo] figured that his small digital video camera served the same purpose as the audio sensors inside the projector, so he put a piece of tissue paper over the lens and wound up with a video that was just frames of gray.
[Urpo] built an app in Processing that averages the pixels in each frame of the video. Of course, recording at 30 frames/second won’t produce any audio this way, so he modulated a triangle wave with this data in Audacity. In the end it really doesn’t sound like much, but it’s great to see such a geeky build.
We’d love to post the video after a break but [Urpo] doesn’t believe in YouTube embeds. We’ll honor his wishes, so you can check out the video here.