Claude Shannon invented the modern mathematical definition of information, casting it in terms of bits and entropy. Shannon also tinkered with odd contraptions, but his boldest most brilliant invention was one called "The Ultimate Machine.'' It was based on an idea of Marvin Minsky.
Image from Lightbucket
The operation and spirit were described by Arthur C. Clarke in his book "Voice Across the Sea: Telstar and the Laying of the Trans-Atlantic Cable":
Nothing could be simpler. It is merely a small wooden casket, the size and shape of a cigar box, with a single switch on one face. When you throw the switch, there is an angry, purposeful buzzing. The lid slowly rises, and from beneath it emerges a hand. The hand reaches down, turns the switch off and retreats into the box. With the finality of a closing coffin, the lid snaps shut, the buzzing ceases and peace reigns once more. The psychological effect, if you do not know what to expect, is devastating. There is something unspeakably sinister about a machine that does nothing -- absolutely nothing -- except switch itself off.
From a biography of Shannon by N.J.A. Sloane and A.D. Wyner.
Several copies of the machine were made and given to executives of AT&T, the parent company of Bell Labs. The above picture of the Machine depicts it be approximately suitcase size, so it is possible that more than one size was produced. I haven't been able to locate any other images.
When asked about the Ultimate Machine Minsky says: "I worked with Shannon at Bell Labs in the summer of 1952. I suggested this machine, Shannon liked it, and he got the company to build a bunch of them and gave them to various executives. I asked for a patent release on it, and they said no, and I didn't pursue it."
In a reminiscence about Shannon James Crow says,
I was fortunate in the 1950s to see Shannon demonstrate this on a television program. The memory is still vivid. The machine was a small closed box with a toggle switch on the front. Shannon flipped the switch. Then the lid opened, with whirring noises in the box, and a small hand emerged and shut off the switch, whereupon the noises stopped and the lid snapped shut.
Nothing is on YouTube yet. Not even sure which show it appeared on.
Of course many machines today have automatic shut-off circuits or valves. But this machine is the only one I know of that consists entirely of a shut-off circuit. However it would not surprise me if some ancient Chinese tinker, or Yankee basement hacker came up with a similar device. Send info if you know more. (Thanks to Michael Naimark for the tip.)
UPDATE: A reader wrote to say he remembers there "was a plastic, toy version of this back in the first half of the 60's," which he was searching for his collection. He has not found the toy yet but he did find a passing remark about it from a book about insurance litigation uncovered in Google books:
My son's favorite toy was a black box. It had a lever on top. To turn it on you flipped the lever on then all heck broke loose. It made all kinds of noise and it rumbled and rolled and kicked around. Finally the top would peek open and a white-gloved hand would come out and swing the lever to the off position. The hand would retreat immediately into the box, the top would slam shut. Total silence. That was it. A toy whose job was to turn itself off.
(The point about this in a lawyerly book was as metaphor for insurance which only turned itself off. "That's this case. We bought our insurance. We asked for it. It made a lot of noise when we tried to turn it on. Then it slammed shut. A policy whose job was to turn itself off.")
Now that he mentioned it I vaguely remember such a thing. Sort of like the Adams Family "Thing." Anyone else seen it?
2nd UPDATE: A reader pointed me to this page which suggests the version of the machine shown in the picture is not Shannon's original, but it does gives a video of it in action. Very cool!