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The Surprise Execution Paradox

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15 replies to this topic

#11 seeksit


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Posted 20 May 2009 - 01:18 PM

Sorry for bumping such an old thread, but it's a good one and the answers haven't explored every aspect.

The absolutely honest judge has given the prisoner two contradicting statements: You will be surprised, and there is no day that you can be executed that you can, in fact, be surprised.

Similarly the absolutely honest husband who makes two condradicting statements to his wife, I'm giving you a gift tomorrow that will surprise you, and it will be that gold necklace we saw at the jewelry store.

In both cases this is a paradox only if the future is perfectly predictable, which it is not. There could be a prison riot and the prisoner could escape. The husband could develop amnesia and get the wrong present.

This operates on the same premise as another old thread here in the paradox section: The Minority Report Paradox. If the seers perfectly predict the future they will know that the crime they are supposedly seeing will be prevented because of their prediction, so there will be no crime for them to foresee. It is a paradox only if they can actually predict the future perfectly; however the physics tells us that it is intrinsically (by the very nature of the laws of physics) impossible for a perfect prediction of the future because, if nothing else, random locations and motions of sub-atomic particles do not have precise values, so cannot be perfectly observed.

Mathematics tries to cram a false absolutism upon an arbitrary, random world. Perfect logic is fundamentally flawed. Here we have the real paradox :P

Edited by seeksit, 20 May 2009 - 01:22 PM.

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#12 James8421


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Posted 21 May 2009 - 06:20 AM

Putting it another way, the more certain the man is
[on Friday night, should he live that long] that he
cannot be hanged on Saturday [the last possible
day for the hanging] the more surprised he is
when it happens. It's possible because of the
prisoner's unwavering belief in the truth of the judge's

As with other semantic paradoxes, the assumption
that what is being asserted is true comes into play.
If the prisoner didn't believe what the judge said
was true, he might [expectantly] dread a Saturday
hanging, thereby precluding it!

The moral:
Never believe a judge. It might cost your head.

I agree, In this case the judge told him he will be surprised. The prisoner(with help from his "logical" lawyer) try their best at disproving the fact that they will be surprised or even hung at all. So it makes sense he would be surprised, after being led to believe that there was no way the judge could hold up to his promises.
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#13 jimbo 12

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Posted 21 June 2009 - 08:43 AM

...On Monday, he has a 20% chance of being hung. If that doesn't happen, then on Tuesday, he has a 25% chance of being hung. On Wednesday, 33.3%, On Thursday, 50%, and if lasts till Friday, 100%.
The last day he always has 100% chance...

Isnt this incorrect. its like the 2 goat and a car behind the doors game show thingy. it is always a 20% chance of happening. on the last day he KNOWS it is a 100% chance that he will be hung that day, but there is still a 20% chance of being hung on friday....
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#14 Austin CG

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Posted 08 July 2009 - 03:39 PM

The problem with these types of paradoxes is that the attourney (in this case), utilizes mathematical logic and not everyday common sense. The only true day that would not be a surprise is saturday. But this day would not be a surprise, only by friday night. On Thursday night both Friday and Saturday are free game. One can't just assume that the judge would eliminate the last day just because it is the last.
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#15 ybom


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Posted 10 July 2009 - 03:12 PM

The judge is either divine, psychic, or in cohorts with the attorney. Such a statement had to be made to put the criminal off guard.

There is a solution, given I play the role of the criminal this time. After my attorney makes his statement, I would then say "Your honor, I choose not to follow the logic of my attorney as it surely condemns me." Then on any day I am summoned to hang, I then say "I am not at all surprised." to the one in charge. If the judges orders are then followed properly, I will not hang as a result of action.

Arseuming does more than make an arse out of you and me, it can also be fatal :)
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#16 music_luvr95


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Posted 27 July 2009 - 10:42 PM

Did the lawyer forget that there is kind of more days then Thursday, Friday, Saturday and Sunday???
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