Modern computing is not immune to logic bombs or race conditions or runaway threads. But it does have techniques to minimize the impact of this. A watchdog timer requires that the program or system periodically pet it, or it will force a reboot. Javascript Runaway timer in browsers will prompt the user to end the script if it notices it overloading the process. Android devices will prompt if an app freezes, allowing you to wait or force close. Programs are sandboxed so that any lockup only affects that program and not the OS. These techniques might not always work but they help.

AI in science fiction tends to go malignant, and logic bombs are used to freeze the computer to save the day. A contradictory statement like "The next statement is true, the last statement was false" will either be catastrophic to the system, causing a meltdown, or at least lock the AI up forever.

One recent SFF question involved a bet that a space station member couldn't break the AI, at which point he presented the above logic bomb, and the AI devoted all resources to evaluating it. All resources, including life support. TNG presented a logic bomb of an impossible geometric shape that would cause the Borg to die off from concentrating everything on it (ethics demanded they didn't use it).

What is the earliest example where these logic bombs simply lock up the AI for a short amount of time, then it just casts it off or reboots, it only takes a small part of its processing power, or it's ignored outright (programmer's foresight)? In realistic writing, a properly programmed computer or AI or machine would not fall to such simple tricks.

  • 1
    There's one by Asimov which I'll add if reopened.
    – SQB
    Commented Jul 17, 2015 at 22:42
  • 1
    "I'll go with true. There, that was easy."
    – Sconibulus
    Commented Jul 18, 2015 at 22:32
  • Do games count? I seem to recall Wheatley shrugging off a bunch of them because he was too stupid and self centered to get caught in them, in Portal 2.
    – K-H-W
    Commented Jul 19, 2015 at 16:56
  • Not strictly a logic bomb, but Asimov's "The last question" could be in the ball park. multivax.com/last_question.html
    – Jaydee
    Commented Jul 21, 2015 at 9:59

3 Answers 3


In the Doctor Who story, The Green Death, the computer (BOSS) is delayed by the Doctor's logic bomb.

From Tardis Wikia

The Third Doctor confused BOSS with a logical paradox (specifically the Liar's Paradox)

If I were to tell you that the next thing I say will be true, But that the last thing I said was a lie, Would you believe me? The BOSS was enraged at its inability to solve this paradox. It even tried to talk its way out of needing to solve it by saying the question was not relevant. The Doctor was quite satisfied with himself at the BOSS' inability to answer, though the BOSS decided to throw the question out the window and simply summon security.

There may be more here

[Edit] - Now that the question has been edited to ask for the earliest instance, I should date this one.
The Green Death, episode 5, first broadcast 16/06/1973.

  • Oh Doctor Who writers, how I love thee
    – user16696
    Commented Jul 17, 2015 at 6:11
  • 1
    "Just once, I'd like to meet an alien menace that wasn't immune to bullets."
    – mpez0
    Commented Jul 17, 2015 at 17:42
  • @mpez0 Season 4 Special, Planet of the Dead.
    – user16696
    Commented Jul 17, 2015 at 20:12

From a programmer's perspective it's pretty simple to protect against such things, given you anticipate them.

"The next statement is true, the last statement was false". For something like this, a good program should just signal a result inconsistence in processing and auto-ignore such a thing, making a log entry and moving on.

Similar thing often cause memory leaks in operating systems. The solution is to somehow end the tasks/process that causes it and the system will maintain it's integrity and keep functioning.

The Borg situation was different because there was no result conflict ...but instead no way of getting to a result ... not fast enough anyway for the resources not to overload. The tactic was to create an impossible shape without the Borg knowing that processing it gets to no valid result. In a realistic scenario, that should not of crashed the Borg systems either (a geometrical shape has limited calculation possibilities even if it is invalid - and the Borg should of just processed for a time or even have a quick protection to come in effect or even ignoring it from start as 'irrelevant'), but thats what happens in movies, the 'good' guys have to somehow cheat their way into winning.

Getting things simple: Super-PI. Many I'm sure know about it. It's a CPU benchmark program that calculates Pi (a number with infinite decimals). Of course, it will never get to a result...so introducing just this simple thing hidden in a program code subroutine would cause any system that runs the program and activates the subroutine to have it's CPU at 100% forever, practically halting or reducing to almost zero it's other activities. This is where other protections suppose to come in.

  • I'm not sure how this answers the question at all. The OP knows all of this. They're asking for a specific episode/movie/book with a specific date where this happens and is then ignored. Commented Jun 28, 2016 at 18:59
  • The question appears to have bee altered. This does not look like the OP initial content.
    – Overmind
    Commented Jun 29, 2016 at 4:51

In Star Trek TOS episode "I, Mudd", broadcast November 3rd 1967, the android "Norman" is so confused by the Liar's Paradox that he lets out his magic smoke.

Also in the episode "Wolf in the Fold", broadcast 22nd December 1967, Spock locks up the Enterprise computer by ordering it to compute pi to the last decimal place.

  • Isn't this the exact opposite of what the OP is asking for? The question asks for instances where the computer ignores the attempt to confuse it. Commented Jun 28, 2016 at 18:57

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