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View Diary: What are you reading? (188 comments)

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    •  Hetty (5+ / 0-)

      The Genius And Madness Of America's First Female Tycoon by Charles Slack

      The future is what we decide it is going to be.

      by Ann T Bush on Wed Jun 24, 2009 at 05:14:06 AM PDT

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      •  I'm Reading Talent is Overrated by (5+ / 0-)

        Geoff Colvin, The Talent Code Greatness Isn't Born, It's Grown, by Daniel Coyle, and Outliers (for the second time) by (My Favorite) Malcolm Gladwell...

        All very good books....  Interesting applications of long held beliefs in success, and it knocks down some myths of success as well.....

        "Look Lois, the two symbols of the Republican Party: an elephant, and a fat white guy who is threatened by change."-Peter Griffin

        by fromdabak on Wed Jun 24, 2009 at 05:29:29 AM PDT

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    •  plf515 - remember my son? (8+ / 0-)

      He has Asperger but is doing great and have been reading Stephen Hawkins and lots of the fantasy books recommended by people here a few weeks ago.  Thanks all for your advice! I found most of them on the BookMooch website, the best thing ever for bibliophiles.  He just finished the DUNE series.

      And he got the Top Ten reader award in his school class of 450 kids! So here is a proud mom..

      "Peace is not something you wish for; It's something you make, Something you do, something you are, and something you give away." Robert Fulghum.

      by profmom on Wed Jun 24, 2009 at 05:46:34 AM PDT

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    •  G.E.B. (4+ / 0-)
      Recommended by:
      RunawayRose, bronte17, plf515, Nulwee

      Godel, Escher and Bach is, in part, about the existence truths that cannot be computed in any consistent system of mathematics. This was an important question in the first thirty years of Computer Science: what things can be computed?

      A few years before G.E.B., Stephen Cook published a paper entitled "The Complexity of Theorem Proving Procedures".  This paper prompted a shift in the field away from the question of what can be theoretically computed toward what could be practically computed.

      Anybody who's ever checked a math problem they've done (e.g., long division) knows that it is often much easier to check an answer than to find a correct one.  Without going into technicalities, problems that are easy to check are called "NP" ("nondetermistic polynomial" which shows why I don't want to go to far into this).  Of course any problem which is easy to solve (a so called "P" problem) is automatically easy to verify; you just solve it again. So all P problems are automatically NP problems. But the opposite is not necessarily true.  There are many practical problems whose answers are easy to check but hard to arrive at using known methods.

      Cook examined one well known NP problem with no known practical solution: determining whether a logical formula is internally consistent. Think of "Colonel Mustard in the Conservatory with the Lead Pipe" from the game Clue.  You win by showing that any solution without Colonel Mustard, the Lead Pipe or the Conservatory is inconsistent.  That's easy to do with a small number of suspects, weapons and places.  There can only be so many clues. But as the number of items and clues increases, it becomes much more difficult.  When we get into the thousands of items and clues level, there is no known method for solving this in a reasonable time, even with the most powerful computers imaginable.

      Cook showed that any solution to this problem could be easily transformed into a solution for any problem that was easy to check (all "NP" problems).  If you had an easy solution for this, you'd have an easy solution to the traveling salesman problem.  You'd break all the cryptography systems in the world, because it's easy to verify that "the attack starts at midnight" and the key "1776" produce a particular enciphered message.

      This is now the central unanswered question of computer science, the so called P=NP problem: is there an easy solution to every easily verifiable problem?   Most researcher believe not. It would be too good to be true, and people have worked on this question for years.

      The philosophical question has changed. Sure, there may be truths that are beyond theoretical computation. But that's not our frontier.  Before we reach those, we confront truths that can't be computed in a practical sense.    A machine with unlimited time would give us an answer, but we don't have unlimited time.  The universe doesn't have unlimited time.   And NP may not be the last word.  NP problems can be practically verified, but there are even problems whose answers can be theoretically verified, but not practically so.

      I've lost my faith in nihilism

      by grumpynerd on Wed Jun 24, 2009 at 06:48:21 AM PDT

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