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Useless machine

Useless machine is a physics topic covered in the lgStudy science library. This page brings together a partial reference excerpt, illustrations, worked examples, real-world applications and a short study plan, so you can understand Useless machine rather than just read about it. In short: A useless machine or useless box is a device whose only function is to turn itself off. The best-known useless machines are those inspired by Marvin Minsky's design, in which the device's sole function is to switch itself off by operating its own "off" switch.

Useless machine — main illustration
Useless machine — illustration

Key takeaways

  • Useless machine belongs to physics; place it in that map before memorising details.
  • Learn the definition first, then one example that makes the definition concrete.
  • Connect Useless machine to a quantity you can measure, compute or draw — that is where exam questions come from.
  • Reproduce the core statement of Useless machine from memory before moving on to harder problems.

Reference excerpt

A useless machine or useless box is a device whose only function is to turn itself off. The best-known useless machines are those inspired by Marvin Minsky's design, in which the device's sole function is to switch itself off by operating its own "off" switch. Such machines were popularized commercially in the 1960s and sold as an amusing engineering hack or as a joke. More elaborate devices and some novelty toys, which have an obvious entertainment function, have been based on these simple useless machines.

History The Italian artist Bruno Munari began building "useless machines" (macchine inutili) in the 1930s. He was a "third generation" Futurist and did not share the first generation's boundless enthusiasm for technology but sought to counter the threats of a world under machine rule by building machines that were artistic and unproductive.

The version of the useless machine that became famous in information theory (basically a box with a simple switch which, when turned "on", causes a hand or lever to appear from inside the box that switches the machine "off" before disappearing inside the box again) appears to have been invented by MIT professor and artificial intelligence pioneer Marvin Minsky, while he was a graduate student at Bell Labs in 1952. Minsky dubbed his invention the "ultimate machine", but this nomenclature did not catch on. The device has also been called the "Leave Me Alone Box". Minsky's mentor at Bell Labs, information theory pioneer Claude Shannon (who later became an MIT professor himself), made his own versions of the machine. He kept one on his desk, where science fiction author Arthur C. Clarke saw it. Clarke later wrote, "There is something unspeakably sinister about a machine that does nothing—absolutely nothing—except switch itself off", and he was fascinated by the concept. Minsky also invented a "gravity machine" that would ring a bell if the gravitational constant were to change, a theoretical possibility that is not expected to occur in the foreseeable future.

Commercial products In the 1960s, a novelty toy maker called "Captain Co." sold a "Monster Inside the Black Box", featuring a mechanical hand that emerged from a featureless plastic black box and flipped a toggle switch, turning itself off. This version may have been inspired in part by "Thing", the disembodied hand featured in the television sitcom The Addams Family. Other versions have been produced. In their conceptually purest form, these machines do nothing except switch themselves off. It is claimed that Don Poynter, who graduated from the University of Cincinnati in 1949 and founded Poynter Products, Inc., first produced and sold the "Little Black Box", which simply switched itself off. He then added the coin snatching feature, dubbed his invention "The Thing", arranged licensing with the producers of the television show, The Addams Family, and later sold "Uncle Fester's Mystery Light Bulb" as another show spinoff product. Robert J. Whiteman, owner and president of Liberty Library Corporation, also claims credit for developing "The Thing". (Both companies were later to be co-defendants in landmark litigation initiated by Theodor Geisel ("Dr. Seuss") over copyright issues related to figurines.) Do-it-yourself versions of the useless machine (often modernized with microprocessor controls) have been featured in a number of web videos and inspired more complex machines that are able to move or which use more than one switch. As of 2015, there are several completed or kit form devices being offered for sale.

Cultural references In 2009, the artist David Moises exhibited his reconstruction of The Ultimate Machine aka Shannon's Hand, and explained the interactions of Claude Shannon, Marvin Minsky, and Arthur C. Clarke regarding the device. Episode 3 of the third season of the FX show Fargo, "The Law of Non-Contradiction", features a useless machine (and, in a story within the story, an android named MNSKY after Marvin Minsky).

See also Arthur Ganson Discard Protocol Jean Tinguely Overengineering Rube Goldberg machine Theo Jansen Trammel of Archimedes

References

Illustrations

Useless machine: A modern "useless machine" about to turn itself off
A modern "useless machine" about to turn itself off
Useless machine: A wooden "useless box"
A wooden "useless box"

Worked examples

Example 1 — a first encounter with Useless machine

Start with the simplest possible case. Write down what Useless machine claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In physics, the smallest case is usually a single object, a single equation or a single measurement. Check that every symbol or term in your sentence has a meaning in that case.

Example 2 — changing one variable

Take the situation from Example 1 and change exactly one quantity: double it, halve it, or set it to zero. Predict what should happen to Useless machine before you calculate. Comparing your prediction with the result is the fastest way to find out whether you understand the idea or only the words.

Example 3 — an exam-style question

Typical questions about Useless machine ask you to (a) state it precisely, (b) apply it to given data, and (c) explain a limitation. Practise writing all three answers in under five minutes; the third part is what separates a full-mark answer from an average one.

Applications of Useless machine

In research
Useless machine appears in physics research whenever the underlying quantities have to be modelled precisely. Papers usually cite it as a starting assumption and then explore where it breaks down.
In technology and industry
Engineering practice reuses Useless machine in design rules, simulations and safety margins. Knowing the idea lets you read a specification sheet and understand why the numbers look the way they do.
In the classroom
Useless machine is common in secondary-school and first-year university syllabi. It links to neighbouring topics Machines, Mechanical toys, Novelty items, so understanding it makes those chapters shorter.
In everyday life
Look for Useless machine outside the textbook — in sport, cooking, traffic, electronics or the sky above you. An example you found yourself is remembered far longer than one you were given.

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How to study Useless machine in 20 minutes

  1. Read the reference excerpt below once, without taking notes.
  2. Close the page and write down what Useless machine means in your own words.
  3. Compare your version with the excerpt and mark what you missed.
  4. Work through the three examples above with pen and paper.
  5. Explain Useless machine out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is Useless machine in simple terms?

A useless machine or useless box is a device whose only function is to turn itself off. The best-known useless machines are those inspired by Marvin Minsky's design, in which the device's sole function is to switch itself off by operating its own "off" switch.

Why does Useless machine matter?

Because it connects several physics ideas at once: it gives you a definition you can apply, a quantity you can calculate, and a way to check whether a result is plausible.

How should I study Useless machine?

Read the excerpt, restate it from memory, then work through the examples and applications listed on this page. The five-step study plan above takes about twenty minutes.

What does this page cover?

It gives you a compact reference excerpt plus original lgStudy explanations, examples, applications and study material on Useless machine.

Tags

  • Machines
  • Mechanical toys
  • Novelty items
  • Office toys
  • Products introduced in the 1950s

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