Our special projects director once wired a circuit into the telecoms cabling duct in the managing director's office.
The circuit was deigned to start making a sound like a clucking chicken, 20 seconds into any incoming phone call.
It took the MD ages to find it because the device was totally silent until a customer phoned him, and then of course he was busy on the phone.
Contra-polar energy... If you phase shift the current 180 degrees to the voltage, an ordinary lamp will be able to emit a beam of dark. They even had the math and a "photo" to prove it. Publish date: April 1, 1970-something, I think it was in a Popular Mechanics.
Anybody remember usenet? Ever read alt.folklore.computers?
Back in 2005, someone (I'm not sure who) identifying himself as "Mike Rowe" claimed to have found about a dozen ADX 7300 computers in a warehouse, and was wondering whether they had any value, or if he should scap them for the gold in their connectors.
Talk about knowing your audience! If you didn't know that an ADX 7300 was a relabeled PDP-1, and that fewer than 50 PDP-1's were ever built, you probably wouldn't care. And if you did know that, you would easily believe it wasn't common knowledge (because it isn't). AFAIK, there are only three PDP-1's known to exist, and they are all in the hands of the Computer History Museum.
You can read the thread here:
What are the engineering and design challenges in creating successful IoT devices? These devices are usually small, resource-constrained electronics designed to sense, collect, send, and/or interpret data. Some of the devices need to be smart enough to act upon data in real time, 24/7. Specifically the guests will discuss sensors, security, and lessons from IoT deployments.