explain xkcd - User contributions [en]

Talk:1655: Doomsday Clock

2016-03-14T22:05:10Z

NickOfFørvania:

Ignoring for the moment that we wouldn't want to deep freeze such a clock, if the scenario is tied only to the hour hand passing vertical the actual sweep of doom is no more than 12h. Perhaps the real problem is that moving the hour hand in this way (unless it can slip) would do some pretty terrible things to the gears. [[User:Elvenivle|Elvenivle]] ([[User talk:Elvenivle|talk]]) 05:30, 14 March 2016 (UTC)
: Or (I'm very tired, please forgive me) at a time rate change of 3600s/s, playing with Google that's an orbital acceleration to about 1/3 lightspeed, magnificent inertial effects and some exciting drag forces. It's no wonder things start on fire. [[User:Elvenivle|Elvenivle]] ([[User talk:Elvenivle|talk]]) 06:11, 14 March 2016 (UTC)

Not only we definitely don't have enough nuclear weapons to destroy the planet, I wouldn't be sure the catastrophe we can do with nuclear weapons would make it into top 10 extinction events. We likely killed more species with deforestation than we would do with nuclear weapons. Especially considering most of those weapons are armed at population centers ... -- [[User:Hkmaly|Hkmaly]] ([[User talk:Hkmaly|talk]]) 11:55, 14 March 2016 (UTC)

Is no one talking about the fact that the title text apparently refers to a digital clock with 24-hour display format, the one used by scientists but despised by most of the US? --[[User:Troy0|Troy0]] ([[User talk:Troy0|talk]]) 12:03, 14 March 2016 (UTC)
: Many digital clocks blink 00:00 when they aren't set regardless of whether they are 12-hour or 24-hour format. So the blinking 00:00 doesn't really say anything one way or the other. Non-blinking, 00:00 would mean midnight in 24-hour format, vs 12:00 or 12:00am in 12-hour format. [[User:N0lqu|-boB]] ([[User talk:N0lqu|talk]]) 18:15, 14 March 2016 (UTC)

Why does Cueball assume that the clock hasn't *already* been moved to DST? [[Special:Contributions/162.158.153.101|162.158.153.101]] 13:53, 14 March 2016 (UTC)

Hasn't Randall said, multiple times, that he hates DST? That was pretty much the first thing I saw. [[User:NickOfFørvania|NickOfFørvania]] ([[User talk:NickOfFørvania|talk]]) 22:05, 14 March 2016 (UTC)

Talk:246: Labyrinth Puzzle

2015-11-04T03:30:22Z

NickOfFørvania:

Just ask which color is the sky.. {{unsigned|‎175.110.37.200}}
:Oh, although the strip doesn't explicitly say so; in those riddles you can normally only ask one question. --[[User:St.nerol|St.nerol]] ([[User talk:St.nerol|talk]]) 23:00, 27 January 2013 (UTC)
::There's another (more traditional) three-guard variation where one guard always tells the truth, one guard always tells a lie and the third alternates between pure truth and pure lie (and you don't know which flip they're currently flopped upon). But you ''still'' only get to ask one question of one guard. Have fun with that one. My personal solution certainly has a degree of convolution, but I've heard other workable answers. [[Special:Contributions/178.98.31.27|178.98.31.27]] 02:24, 21 June 2013 (UTC)
:::@‎175.110.37.200, you would know which one lies but you would not know which door leads out. [[User:Tharkon|Tharkon]] ([[User talk:Tharkon|talk]]) 23:13, 10 October 2013 (UTC)
::::Eh, well, even if you had a perfect question to ask in this case, a lot of good would that do you: it'd only reveal the truth behind the setup, that ''none'' of the doors lead out. :p -- [[Special:Contributions/173.245.51.210|173.245.51.210]] 08:20, 8 November 2013 (UTC)
:::::Well yes it says that in the title-text. But good pick-up. [[Special:Contributions/108.162.219.58|108.162.219.58]] 02:31, 6 February 2014 (UTC)

One question, of one guard. I really like the original form of this riddle. It's a bit of a trick, though. It is crucial that the guards "know" each other's rules, but this is not even implied. And if it was stated in the question, that would probably be a good enough clue to get you to the answer. Of course, once you know the answer it seems trivial, but I wonder what percentage of people actually worked it out for themselves? Another good one is Monty Hall, even though that is pure, straightforward probability. [[Special:Contributions/108.162.219.223|108.162.219.223]] 18:11, 17 January 2014 (UTC)

:I think somebody needs a hug! [[Special:Contributions/108.162.219.223|108.162.219.223]] 18:11, 17 January 2014 (UTC)

The whole problem with this entire riddle is that if they are both liars you are screwed! Nothing in the riddle establishes a fact that they aren't liars. Now if there was a known truth teller in the riddle that explains the nature of the guards or the narrator does it, then the above solution works. {{unsigned ip|108.162.216.28}}

As you aren't given a limit to the number of questions, you can just ask each guard if they're the stabby guard. If two say yes, the third one is the truthful guard and you can ask him which way the exit is. If two say no, the third one is the lying guard and you can ask him where the exit isn't. No tricky questions so the stabby guard shouldn't stab you.[[Special:Contributions/162.158.255.195|162.158.255.195]] 18:14, 14 August 2015 (UTC)

I have a solution, but you need to ask multiple questions: 
''If the Stab Guard tells the truth:'' 
Ask each guard, firstly, "Are you the Stab Guard?" 
Truth Guard will answer "No." 
Stab Guard will answer "Yes." 
Liar Guard knows the answer is no, but, because he lies, will answer "Yes." 
The one who said no is the Truth Guard, so you can ask him which door leads to freedom. 
''If the Stab Guard lies:'' 
Point to the guard on the left, and ask each guard, "Does that guard lie?" 
If that guard is Truth Guard, then Truth Guard will answer "No," while Stab Guard and Liar Guard answer "Yes." 
If that guard is a liar, then Truth Guard will answer "Yes," while Stab Guard and Liar Guard answer "No." 
Whichever guard gives a unique answer is Truth Guard, so you can ask him which door leads to freedom. [[User:NickOfFørvania|NickOfFørvania]] ([[User talk:NickOfFørvania|talk]]) 23:37, 3 November 2015 (UTC)

Talk:246: Labyrinth Puzzle

2015-11-03T23:37:25Z

NickOfFørvania:

Just ask which color is the sky.. {{unsigned|‎175.110.37.200}}
:Oh, although the strip doesn't explicitly say so; in those riddles you can normally only ask one question. --[[User:St.nerol|St.nerol]] ([[User talk:St.nerol|talk]]) 23:00, 27 January 2013 (UTC)
::There's another (more traditional) three-guard variation where one guard always tells the truth, one guard always tells a lie and the third alternates between pure truth and pure lie (and you don't know which flip they're currently flopped upon). But you ''still'' only get to ask one question of one guard. Have fun with that one. My personal solution certainly has a degree of convolution, but I've heard other workable answers. [[Special:Contributions/178.98.31.27|178.98.31.27]] 02:24, 21 June 2013 (UTC)
:::@‎175.110.37.200, you would know which one lies but you would not know which door leads out. [[User:Tharkon|Tharkon]] ([[User talk:Tharkon|talk]]) 23:13, 10 October 2013 (UTC)
::::Eh, well, even if you had a perfect question to ask in this case, a lot of good would that do you: it'd only reveal the truth behind the setup, that ''none'' of the doors lead out. :p -- [[Special:Contributions/173.245.51.210|173.245.51.210]] 08:20, 8 November 2013 (UTC)
:::::Well yes it says that in the title-text. But good pick-up. [[Special:Contributions/108.162.219.58|108.162.219.58]] 02:31, 6 February 2014 (UTC)

One question, of one guard. I really like the original form of this riddle. It's a bit of a trick, though. It is crucial that the guards "know" each other's rules, but this is not even implied. And if it was stated in the question, that would probably be a good enough clue to get you to the answer. Of course, once you know the answer it seems trivial, but I wonder what percentage of people actually worked it out for themselves? Another good one is Monty Hall, even though that is pure, straightforward probability. [[Special:Contributions/108.162.219.223|108.162.219.223]] 18:11, 17 January 2014 (UTC)

:I think somebody needs a hug! [[Special:Contributions/108.162.219.223|108.162.219.223]] 18:11, 17 January 2014 (UTC)

The whole problem with this entire riddle is that if they are both liars you are screwed! Nothing in the riddle establishes a fact that they aren't liars. Now if there was a known truth teller in the riddle that explains the nature of the guards or the narrator does it, then the above solution works. {{unsigned ip|108.162.216.28}}

As you aren't given a limit to the number of questions, you can just ask each guard if they're the stabby guard. If two say yes, the third one is the truthful guard and you can ask him which way the exit is. If two say no, the third one is the lying guard and you can ask him where the exit isn't. No tricky questions so the stabby guard shouldn't stab you.[[Special:Contributions/162.158.255.195|162.158.255.195]] 18:14, 14 August 2015 (UTC)

I have a solution, but you need to ask multiple questions:
''If the Stab Guard tells the truth:''
Ask each guard, firstly, "Are you the Stab Guard?"
Truth Guard will answer "No."
Stab Guard will answer "Yes."
Liar Guard knows the answer is no, but, because he lies, will answer "Yes."
The one who said no is the Truth Guard, so you can ask him which door leads to freedom.
''If the Stab Guard lies:''
Point to the guard on the left, and ask each guard, "Does that guard lie?"
If that guard is Truth Guard, then Truth Guard will answer "No," while Stab Guard and Liar Guard answer "Yes."
If that guard is a liar, then Truth Guard will answer "Yes," while Stab Guard and Liar Guard answer "No."
Whichever guard gives a unique answer is Truth Guard, so you can ask him which door leads to freedom. [[User:NickOfFørvania|NickOfFørvania]] ([[User talk:NickOfFørvania|talk]]) 23:37, 3 November 2015 (UTC)