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Topic: Past, Present, Future (Read 9318 times) |
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Jonathan the Red
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Re: Past, Present, Future
« Reply #25 on: Aug 5th, 2002, 9:39am » |
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Well, here's a link to the program.
Keep in mind (please!) that this is NOT my best code by any means... it's extremely quick and dirty. As I said, it's very brute-force... it basically goes through every possible combination of questions and Gods and determines which produce unique solutions. It comes up with 576 answers, but there's at least 6-fold symmetry and probably more.
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Eric Yeh
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Re: Past, Present, Future
« Reply #26 on: Aug 5th, 2002, 10:26am » |
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I beg to differ on your answers to "Is Water Wet". 
(Ok, maybe not.  )
First off: nice program! Anything that finds a solution is already pretty nice, of course.
However, as I suspected, you have to feed it a finite number of questions, whereas there are potentially infinitely many. Ok, maybe there are only 218 or something like that, and maybe it collapses further, but in any case it's something bigger than 34, right? I would suspect that, having seen the code, I could probably devise a new problem specified to stump it...
Or have I missed something, and these thirty-four questions actually somehow span?
Best,
Eric
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Jonathan_the_Red
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Re: Past, Present, Future
« Reply #27 on: Aug 5th, 2002, 10:39am » |
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Oh, I'm certainly not claiming that the set of questions is exhaustive... in fact, it definitely isn't. I was able to increase the solution set to 744 (including trivial 6-way symmetry) by adding "Are you earlier than [A|B|C]" and "Is water dry" to the domain of questions. And I'm sure you could get even more solutions by adding compound questions ("Are you future or is God B Past?" "Is God C Future if and only if you are not later than God A?" etc etc etc). My goal was not to come up with every possible solution, just one.
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Eric Yeh
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Re: Past, Present, Future
« Reply #28 on: Aug 5th, 2002, 10:57am » |
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Jon,
Fair enough; I wasn't sure whether you were making the claim or not An I would also have been curious if there was a way to prove that your set spanned.
On another note: cool, you've finally registered!!! I'll be looking forward to your continued posts!
Best,
Eric
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Chronos
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Re: Past, Present, Future
« Reply #29 on: Aug 6th, 2002, 2:38pm » |
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Quoth Jonathan the Red: Quote:| The question is: does he answer "Splunge" because that's the correct answer to "Are you Past?", or does he answer "Fleen" because that's the correct answer to "Is God A Past?" |
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The pronoun "you" must reference the god currently being addressed, rather than the god addressed when a question is asked. Otherwise, we can get paradoces involving the prescient god Future, since you can choose of whom you ask each question. To use your example: A is present, B is past, C is future, Splunge is yes, Fleen is no.
My first question is the irellevant Carrot Top one. My second question is "Are you Present?".
Now, I ask my first question of god C. Since he's Future, he ignores the Carrot Top question, and instead tells me the answer to question 2. But he can't tell me whether the person I ask question 2 is Present, because I haven't yet decided who I will ask question 2, so we can get paradoces. He must interpret "you" to mean himself.
On another note, Jonathan the Red's solution to the language barrier only works if you know that "splunge" is one of the words the gods use. If you've just entered the chamber, you probably don't know anything about their language.
However, there's still no barrier. If the gods are truly omniscient, then they know English, and they do not desire to deceive. Therefore, you just request that they respond in English, rather than in their native tongue.
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Eric Yeh
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Re: Past, Present, Future
« Reply #30 on: Aug 6th, 2002, 2:46pm » |
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Go Chronos! I see you are already an expert on my puzzle! You know, there's something quite cathartic about seeing someone else give explanations for your problem! 
Best,
Eric
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| « Last Edit: Aug 6th, 2002, 2:46pm by Eric Yeh » |
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Jonathan_the_Red
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Re: Past, Present, Future
« Reply #31 on: Aug 6th, 2002, 3:38pm » |
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on Aug 6th, 2002, 2:38pm, Chronos wrote:To use your example: A is present, B is past, C is future, Splunge is yes, Fleen is no.
My first question is the irellevant Carrot Top one. My second question is "Are you Present?".
Now, I ask my first question of god C. Since he's Future, he ignores the Carrot Top question, and instead tells me the answer to question 2. But he can't tell me whether the person I ask question 2 is Present, because I haven't yet decided who I will ask question 2, so we can get paradoces. He must interpret "you" to mean himself.
[...]
However, there's still no barrier. If the gods are truly omniscient, then they know English, and they do not desire to deceive.
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If the Gods are truly omniscient, Future knows full well to whom you will direct the next question. For crying out loud, he already has to predict the future in order to know what your question is so that he may answer it; you think he's not capable of divining the target as well?
In any case, the problem is solvable without using the word "you." Here's a set of questions that works:
(highlight below to read)
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Question #1: Is B Future? (asked of God A)
Question #2: Is B Present? (asked of God A)
Question #3: Is A Future? (asked of God C if the answer to #2 was yes, God A if no.)
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| « Last Edit: Aug 6th, 2002, 3:46pm by Jonathan_the_Red » |
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Eric Yeh
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Re: Past, Present, Future
« Reply #32 on: Aug 6th, 2002, 8:31pm » |
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No no Jon, your answer was right the first time. (Well, this one is right, too, but unnecessary.) Unless I am reading it totally incorrectly, Chronos' message did not invalidate your previous soln, which also used dynamic scoping in the proper way.
Chronos: you are correct that I slipped up when I reworded the problem recently -- it was originally a "da and ya" problem, but I took too much of a poetic license in the rewrite. Sometime I will get Will to fix this.
Best,
Eric
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Ryan Lawrence
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Re: Past, Present, Future
« Reply #33 on: Aug 7th, 2002, 12:10am » |
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Hallo,
When you rewrite the problem, you may want to clarify the "rules" of the questioning. I've had a few people look at the riddle and none of them could really figure out who would answer which question and when For example, if I asked Future the first question would it answer at all and when?
It is difficult to discern the answer to a riddle when you do not know exactly how the elements are going to react.
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Eric Yeh
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Re: Past, Present, Future
« Reply #34 on: Aug 7th, 2002, 5:53am » |
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Ryan,
Each god (always the one asked), always answers the question immediately. The only difference made by their "personalities" is which question they choose to answer. In your example, Future immediately answers the second question in the first round.
In general, a good way to check this sort of thing is to ask whether the question makes "sense" in the different scenarios. In any case where the answers come temorally shifted as well, it is easy to solve in two questions instead of [relatively] hard to solve in three; thus, it would not make "sense" for me to ask that you solve it in three. I understand, however, that you have no reason as yet to trust me as not just being an idiot.
To the open audience:
Does anyone else have any other complaints about the wording of my puzzle? I thought it was worded in a fairly clear manner, but I see that there is always room for alternate interpretations. Any feedback would be greatly appreciated.
Best,
Eric
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Eric Yeh
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Re: Past, Present, Future
« Reply #35 on: Aug 8th, 2002, 1:44pm » |
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Ok, I've gotten no replies to this.  So here's what I've come up with so far on my own:
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PAST, PRESENT, AND FUTURE
There are three omniscient gods sitting in a chamber: Past, Present and Future. They are all truthful, but with the following caveat: Present answers the question currently being asked, Past answers the last question asked in their chamber, and Future answers the next question which will be asked in their chamber. Despite their manipulation of which question to answer, each still answers immediately as if answering the question currently being asked.
Furthermore, the gods answer in a language in which "yes" and "no" are replaced by "da" and "ya", but you do not know which is which. You only know that their answers are consistent amongst themselves.
With three questions, determine which god is which.
[Notes:
Standard: (Rules that are generally assumed unless otherwise noted.) The gods only answer yes/no questions. Each god answers in the single word of their language as appropriate to the question; i.e. each god always gives one of only two possible responses, one affirmative and one negative (e.g. they would always answer "Yes" rather than "That would be true"). Each question asked must be addressed to a single specific god; asking one question to all the gods would constitute three questions. Asking a single god multiple questions is permissible. The question you choose to ask and the god you choose to address may be dynamically chosen based on the answers to previous questions.
Specific: Because of possible time conflicts, you must determine your questions ahead of time, rather than based on previous answers. However, you are still allowed to choose who you ask each of your three questions to dynamically. Scoping is also dynamic; e.g. the pronoun "you" in a question will always refer to the person to whom you are currently asking a question, not a predetermined person). No time related questions (e.g., "if the answer to my second question was 'no', then X otherwise Y") are permissible, as this could lead to paradoxes within the space-time continuum). Finally, note that if you ask Past your first question or Future you last question, the answer will give you no additional information because you do not know what the last or next questions are!!]
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I've tried to hit every possible question I've gotten about this, and I think it's pretty comprehensive. Any thoughts? Ryan, does this clear up all the issues you had?
Will, could you post this for me?
Semi-random shameless plug: I have another new one coming!! Watch for it on the message board!! This one was inspired by some of the experiences I've had here, so many thanks to those who have looked at my puzzle and discussed it with me! If you guys enjoyed this one, please give my new one a shot, too. It is specifically designed as anti-Jon, anti-program. Haha, jk, you know I love you Jon.
Best,
Eric
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Chronos
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Re: Past, Present, Future
« Reply #36 on: Aug 15th, 2002, 12:20pm » |
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Quote:| If the Gods are truly omniscient, Future knows full well to whom you will direct the next question. For crying out loud, he already has to predict the future in order to know what your question is so that he may answer it; you think he's not capable of divining the target as well? |
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In general, precognition will lead to paradoces. Yes, Future knows who the target of your question will be, but what if you choose the target of your question based on Future's answer? Suppose, for instance, that before you ask any questions, you guess which god is which, and which word is which, and you happen to be right (this is certainly possible). You then decide "If Future tells me that the next question will be asked of Present, then I'll ask it of Past, instead". This would make Future wrong, which is against the premises of the riddle.
Eric gets around this by setting up the problem so that Future doesn't actually need precognition. You have all of your questions chosen ahead of time, so he doesn't need to see the future to know your question, he just has to read your mind (a much easier proposition). And he doesn't need to know who you're going to ask the questions of, since the pronoun "you" will refer to himself anyway. Strictly speaking, you need to disallow any questions about the questioner's future actions: Otherwise, you could ask "Am I about to stick out my tongue", or some such.
And Eric, I'm not an expert on this puzzle specifically; I just have a lifelong obsession with time travel, causality paradoces, and related matters
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Eric Yeh
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Re: Past, Present, Future
« Reply #37 on: Aug 15th, 2002, 12:34pm » |
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on Aug 15th, 2002, 12:20pm, Chronos wrote:| You have all of your questions chosen ahead of time, so he doesn't need to see the future to know your question, he just has to read your mind (a much easier proposition). |
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Much easier indeed!!
on Aug 15th, 2002, 12:20pm, Chronos wrote:| And Eric, I'm not an expert on this puzzle specifically; I just have a lifelong obsession with time travel, causality paradoces, and related matters |
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No problem dude, you offer an excellent explanation as usual!!
Best,
Eric
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Hippo
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Re: Past, Present, Future
« Reply #38 on: Mar 18th, 2007, 9:46am » |
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I agree with chronos (btw: well chosen name) ... the problem with puzzle is that you must dynamically switch question targets and that can lead to "this statement is false" paradoxes. ... so we will need 4 answers ... yes/no/paradox unsatisfable/paradox always satisfable.
The other (smaller) problem was mentioned by chronos, too ... you need to know one of the words the gods use for yes/no. (At least for Jonathan solution).
Of course you cannot distinguish 2.3!=12 initial cases by 3 yes/no questions so you cannot find which word means yes and which no.
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Eric Yeh
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Re: Past, Present, Future
« Reply #39 on: Mar 18th, 2007, 8:56pm » |
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hippo,
i dont think youve read chronos' msg quite correctly. its been a long time and i just looked quickly, but my understanding/recollection is that his msg was a defense rather than attack on the problem. see how he says "eric gets around this by..."
in any case:
1. i believe that i had gotten rid of all paradoxes with the proposition that there are no time related questions allowed. however, feel free to give me an example just in case that is not enough. if absolutely necessary, i can always reword it to say that anything that could allow for a paradox in any permutation would be impermissible to the gods. in any case, it is pretty clearly unnecessary to use any such trickery to solve the problem, so its just a problem plug that i dont think anyone should particularly focus on.
2. i seem to have reworded it on aug 8 2002 so that this is not an issue. however i am rather tempted to say that using the 'gods of gibberland' innovation should work in this case too, but dont feel like taking the time to test this just now. i am also surprised that i did not use that innovation back in 2002, which leads me to slightly suspect that perhaps it doesnt work. anyway, ill let someone else figure it out.
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srn437
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Re: Past, Present, Future
« Reply #40 on: Aug 27th, 2007, 10:05am » |
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What if I ask:
question 1-to god 1-does 1+1=2
question 2-god 2-is the answer to the next question yes
question 3-god 3-does 1+1=3
This is without the language thing though. I am not sure how this one works, but I know it works.
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| « Last Edit: Aug 28th, 2007, 12:24pm by srn437 » |
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temporary
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Re: Past, Present, Future
« Reply #41 on: Jan 27th, 2008, 3:15pm » |
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Perhaps there is a way to use these paradoxes to my advantage...
For example, if I ask a"am I going to ask b the next question" and I plan on asking b the next question if he says no, or a or c if he says yes, and the universe starts falling apart, I know that either a is present, or I am going to ask past my next question.
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My goal is to find what my goal is, once I find what my goal is, my goal will be complete.
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Shelter417
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Re: Past, Present, Future
« Reply #42 on: Oct 20th, 2008, 2:41pm » |
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Any chance of someone posting the proofs? This is a very interesting puzzle.
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