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CTK Exchange
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mawcowboy
Member since Dec-4-03
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Dec-04-03, 05:28 PM (EST) |
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2. "RE: 4 colour mapping"
In response to message #1
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A formal proof guarantees its conclusion(s).Currently, there does not exist a manipulation of algebraic symbols to obtain any formal proof of the Four Color Theorem. Proofs of the Four Color problem are most directly related with the history of Proof Without Words. ( search this site ) Four Color theorem 'proofs' are diagrams. If we see enough cases in which something is true and we never see a case in which it is false, we tend to conclude that it is always true. This type of reasoning by example is called inductive reasoning. Inductive reasoning is not considered proof within formal logic. Deductive reasoning is the only one that guarantees its conclusions.
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Hypercoyote
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Nov-17-04, 00:37 AM (EST) |
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3. "RE: 4 colour mapping"
In response to message #0
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Does anyone know where to find the computer code they used to actually prove the 4 color theorem? I heard it was made publicly availible for refutation, but apparently not that publicly, because I cannot find it anywhere!!! |
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rewboss
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Nov-19-04, 07:36 AM (EST) |
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4. "RE: 4 colour mapping"
In response to message #0
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What you've done, in effect, is to draw a few maps and then say, "Hey, I can't figure out how to draw a map that requires more than four colours". That's as far as the best mathematical brains got (at least before the advent of computers) -- nobody had been able to construct a map requiring more than four colours (and they tried a lot harder than you did), but that doesn't mean it's impossible. |
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Starlight
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Jul-18-06, 08:47 AM (EST) |
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5. "RE: 4 colour mapping"
In response to message #4
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Oh, I have to love these. If you mathematically prove that the 5 colour theorem is true and useful in maps, then why not use it in a map? Using the same example in a theorem should make it'simple. This isn't to say it's impossible, it's to say there's no point to proving it. You're never going to have a living example of it. A proof without a visual is like asking a child to believe in god. They don't get it, but they'll do what their parent wants. Please, do explain the proof. Preferably in colour. |
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Silas
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Oct-25-06, 06:37 AM (EST) |
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6. "RE: 4 colour mapping"
In response to message #5
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You don't have to use the 5-color theorem in a map, because nobody has ever demonstrated a counter-example to the four-color theorem. In a sense the problem is not proving the four-color theorem - it is disproving it. Proving the four-color theorem just has mapmakers saying, "Phew!" and not having to worry about buying that fifth crayon. But if it were disproved, then the mathematical worlds opening up due to the vision of a kind of map nobody had ever seen or made use of before, could be almost limitless. However, it'seems that, even though it is not an algebraic proof, there really will never be a counter-example and such dreams of finding new ways of mapping (or of new worlds to map) are come to nought. In the absence of any real need for five colors, the hunt for a rigorous demonstrable proof is itself the hunt for new mathematical worlds, in which proof without words is not sufficient. |
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Mark Huber
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Oct-27-06, 06:44 AM (EST) |
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7. "RE: 4 colour mapping"
In response to message #6
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The four-color theorem is more interesting from a socialogical rather than a mathematical point of view. When the proof came out in the 70's, there was a lot of excitement, and many felt that computerized proofs of mathematics theorems were the wave of the future. Simply put, that hasn't happened. Math journals are still pretty much the same as they were in the 70's, or even before the advent of the modern computer. What has changed is at the level of experimentation: a mathmatician nowadays will try to check what he or she believes to be true with as many computer generated examples as possible, before going for the full-blown mathematical proof. And it turns out in the end not to be a very important problem. More interesting is the following: given a general graph (not necessarily planar), what is the minimum number of colors needed to color it? This problem is NP hard, and will get you a cool million from the Clay institute if you find a polynomial time algorithm that answers the question. |
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