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- Newsgroups: sci.physics
- Path: sparky!uunet!usc!sdd.hp.com!ux1.cso.uiuc.edu!news.iastate.edu!pv343f.vincent.iastate.edu!abian
- From: abian@iastate.edu (Alexander Abian)
- Subject: TIME HAS INERTIA - GOEDEL's THEOREMS - att: Dr.PRATT, Mc CULLOUGH
- Message-ID: <abian.726695664@pv343f.vincent.iastate.edu>
- Sender: news@news.iastate.edu (USENET News System)
- Organization: Iowa State University, Ames IA
- Date: Sun, 10 Jan 1993 19:54:24 GMT
- Lines: 177
-
- Summary: Completeness and two Incomplteness Theorems of Goedel
- Keywords:
-
- TIME HAS INERTIA
-
- STRICTLY FOR DEVOTED READERS OF: TIME HAS INERTIA
-
- ON GOEDEL's THEOREMS: att: Dr. PRATT and Mc CULLOUGH
-
-
- In our attempt to model THE PLANET EARTH we construct GLOBES that
- can be bought, say, in bookstores.
-
- Question 1. DOES A GLOBE CONSTRUCTED ON THE PLANET EARTH AND
- LOCATED, say, ON THE NORTH POLE OF THE PLANET
- EARTH, MODEL THE PLANET EARTH ?
-
- This is essentially the central question involved in Goedel's INCOMPLETE-
- NESS theorem.
-
- The answer is NO !
-
- PROOF. Assume on the contrary that the Globe that we constructed and
- located on the North Pole of the Earth models the Earth. Then our planet
- Earth now has a Globe on its North Pole, whereas our Globe does not have
- a Globe on its North Pole. Thus, our Globe does not model our Planet
- Earth. But this contradicts our assumption. Thus, our constructed Globe
- which is located on the planet Earth does not model the planet Earth.
-
- Hence, our answer "NO" is proved.
-
- Note that locating the Globe on the North pole is not essential.
- Analogous proof can be given no matter where ON THE PLANET EARTH
- the Globe is located.
-
- Note also that in the above example it is not essential that the Globe
- is necessarily constructed on the planet Earth.
-
- The essential implication of the above Proof is:
-
-
- (G2) A MODEL OF THE PLANET EARTH SYSTEM CANNOT BE PROVED TO
- EXIST ON THE EARTH SYSTEM ITSELF
-
-
- Question 2. DOES A GLOBE OF PLANET EARTH, CONSTRUCTED AND
- LOCATED ON THE MOON, MODEL THE PLANET EARTH ?
-
-
- The answer is: YES !
-
- PROOF. The construction of the Globe on the Moon and its
- locating on the Moon does not alter the Earth. So it does model the
- Earth.
-
- The essential implication of the above proof is:
-
-
- (E2) A MODEL OF THE PLANET EARTH SYSTEM CAN BE PROVED TO
- EXISTS ON A MORE POWERFUL EXTENDED EARTH-MOON SYSTEM
-
-
- (There are some crackpots who in contradistinction to (G2) claim that
- locating Globe 1 on the North pole of the Earth, then locating
- Globe 2 on the North pole of Globe 1, then locating Globe 3 on the
- North pole of Globe 2, then locating Globe 4 on the North pole of
- Globe 3 AND SO ON ... allows the construction of a Model of the system
- on the system itself. Indeed, these crackpots claim that everyone of
- the Globes 1, 2, 3, 4, ... does model the system. Of course, the
- Professional Guardians of Logic disagree with these crackpots because
- the usage of the words AND SO ON).
-
- The (G2) statement above is the heart, the emotional fiber,
- the romantisized, subconsciously powerful and profound version of
- the OFFICIAL AND FORMAL GOEDEL'S SECOND INCOMPLETENESS THEOREM
- which I will mention shortly.
-
- First, however, let me mention that by Goedel's CMPLETENESS
- Theorem:
- THE CONSISTENCY OF THE FORMAL FIRST ORDER THEORIES AND
- THE EXISTENCE OF MODELS FOR THEM are equivalent statements,
-
- i.e.,in a crackpotish way, we can say:
-
- (C1) A system of statements is consistent if and only if
- there exists a model for that system
-
- a more crackpotish way, is to say:
-
- (C1) Consistency is the same thing as having models
-
- where, of course a system of statements is called consistent if no
- statement and its negation are both derivable from the system
- (all this in reference to FIRST ORDER THEORIES -consult any
- graduate MATH LOGIC or MODEL theoretic textbook- there are
- dozens of them)
-
- Now, the OFFICIAL, FORMAL Statement of Goedel's Second
- Incompleteness Theorem (the emotional version of which I gave
- in (G2) above) is:
-
- (GOEDEL 2) Let S be a formal first order system whose axioms are
- given by some recursive rule. If S is consistent and
- the partial recursive functions can be embedded in S, then
- consistency of S (i.e., con S) cannot be proved in S.
-
-
- Now, what is Goedel's First Incompleteness Theorem?
-
- The emotional, romantisized, subconsciously powerful and deep
- version of Goedel's First Incompleteness theorem is:
-
- (G1) THERE EXISTS NO INFINITE MODEL THAT CANNOT BE EXTENDED
- TO A LARGER MODEL MODELING OBJECTS THAT COULD NOT
- BE MODELED IN THE ORIGINAL MODEL.
-
- For instance if the objects of a model are all finite subsets of
- integers, we may extend it in variety of ways by various infinite
- subsets of integers.
-
- The Formal statement of (G1) is:
-
- (Goedel 1) Let S be a formal first order system whose axioms are
- given by some recursive rule. If S is consistent and the
- partial recursive functions can be embedded in S then
- there exists an UNDECIDABLE statement p such that neither
- p nor its negation -p (not p) can be proved from the
- axioms of S.
-
- (for this Formal statement consult any graduate text of Math Logic
- or Model Theory)
-
- Clearly, (Goedel 2) is a special case of (Goedel 1) where p
- can be taken as "con S".
-
- Thus, any formal system such as S will always have an unde-
- cidable statement, a fact that shattered into pieces, smashed and
- delivered the death blow to Hilbert's program of trying to prove the
- consistency of systems such as S (or more powerful than S) by finit-
- istic methods.
-
-
- I am exhausted and it is time to listen to Chopin's 24 th etude
- in C minor. I think I mistyped in my last nights posting by typing
- Chopin's 24 th etude in A minor, I meant Chopin's 23 rd etude in A minor.
-
- This morning I had 12 e-mail messages. As I have repeatedly
- mentioned, I do not read my e-mail messages and all the 12 e-mail
- messages were deleted.
-
- Please communicate with me EXCLUSIVELY via sci.physics
-
- Subject; TIME HAS INERTIA.
-
- With love, Alexander Abian
-
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- --
- The tendency of maintaining the status-quo, Reaction to provocation and
- The tendency of maintaining again a status-quo.
- TIME HAS INERTIA and some energy is lost to move Time forward
- E = mcc (Einstein) must be replaced by E = m(0) exp(-At) (Abian)
-