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[Xmca-l] Objectivity of mathematics



Some people will be familiar with this:

1. If a = b 2. then a^2 = ab
3. then a^2 - b^2 = ab -b^2
4. then (a-b)(a+b)=(a-b)b
5. then a+b=b
6. then, because a=b, 2b=b
7. then 2=1

This proof appears to follow the "social conventions" that kids are taught in algebra, but arrives at an absurdity. The reason is that the deduction from 4 to 5 is an error. "Cancelling out the (a-b)" doesn't work if (a-b)=0. The limitation that the divisor be not zero, is obviously not there just for a social convention. It *objectively,* has to be introduced because otherwise, the common factor rule has the capacity to destroy the entire system. The rules governing the above operations must conform to objective constraints which belong entirely to the world of mathematics, and have nothing to do with the world beyond the text. It doesn't matter if a and b represent lengths or baseball scores.

Despite what the advocates of discourse theory believe mathematics is subject to a whole range of constraints, and reveals a whole lot of relationships and symmetries, which have nothing to do with the world outside of mathematics, of "applications." Social conventions have to adhere to these objective constraints to make good mathematics, irrespective of whether they reflect material interactions.

Andy
(PS I don't know the above equations are going to look after going through the mail server. Let's just hope for the best.)

------------------------------------------------------------------------
*Andy Blunden*
http://home.pacific.net.au/~andy/


Ed Wall wrote:
Andy

Yes, I recall Piaget's claim (Piaget gathered a cadre of mathematicians around him in his later years). Mathematicians tend to come back and do 'foundations' after they have been playing around for a number of years. Beginning at an end point (which was, in large measure, what the curriculum of the 1980s did) may have been a large part of the problem.
       I've been thinking and realized that I may not be clear about what you mean by 'objective relations.' What makes a relation objective versus the opposite?

The journey of discovery that mathematics offers is, I think, reasonably exciting. However, so many children (and adults) find it dead boring and intellectually repulsive. Some of that may be social convention (I remember a mother of one of my algebra students complaining because her daughter was 'too' involved in doing mathematics; it wasn't 'girl like') , but some of it may be teaching/curriculum. There is an amusing article "Lockhart 's Lament" which sort of touches on this (Devlin gives the link in a brief intro):
      https://www.maa.org/external_archive/devlin/devlin_03_08.html

Ed

On Oct 30, 2014, at  6:28 PM, Andy Blunden wrote:

:) So many issues.

Ed, do you recall Piaget's claim of ontogeny repeating history in mathematics. I read it in "Genetic Epistemology" but I am sure he would have formulated the idea elsewhere. I found the formulation in that book highly unconvincing at the time. Interesting in that respect is that the logical sequence of relations within mathematics is opposite to the historical sequence, and how (in my experience) the efforts in the 1970s to make ontogeny follow logic proved so unsuccessful. But maybe this failure was due to contingencies, I don't know.

And apart from Hilbert/Godel/Turing's demolition of Principia Mathematics, Russell's demolition of Frege logicism was also very profound. Both of course proved that mathematics is constrained by objective relations and social conventions have to conform to that objectivity or they fail.

The first thing, in my view, is to establish that, whatever this or that group of people believe to be the case, mathematics is a science which is constrained by objectively existing relations and reveals those relations, which are nothing to do with the laws of physics, space-time, and the infinite complexity of reality, etc. I think the journey of discovery which is available to children has the potential to both teach and endear mathematics for people. Learning social conventions is dead boring and politically repulsive (if separated from natural necessity), to my mind.

Andy
------------------------------------------------------------------------
*Andy Blunden*
http://home.pacific.net.au/~andy/


Ed Wall wrote:
Carol and Andy

        In the historical record, the first time I see the distinction being clearly drawn between mathematics and the material world is with Aristotle. However, he did not write in a vacuum and the paradoxes of Zeno clearly indicated some problems (for instance, the story of Achilles and the Hare). You can also see in the stories of Socrates that mathematics was being done for the sake of the mathematics (for instance, the Meno). There are some indications of the same fascination early on in India (the Chinese tended to be fairly pragmatic).

       I was raised, in a sense, to observe the distinction Andy makes below concerning 'objective.'. Godel muddied the water a bit with his first and second incompleteness theorems, capsizing, so to speak, the monumental work - Principia Mathematica - of Russell and Wittgenstein. Anyway, I wonder (and I am searching for words here) if children 'naturally' realize such objective validity, but are rather immersed in talk of such and come out brain washed (a little of 'which comes first the chicken or the egg'). I find it hard, I guess, to draw a fine line between objective validity and social convention (and, as to this latter, I have in mind the interactions among 'mathematicians.') For example, when a mathematical paper is referred, the logic of argument is not 'completely' analyzed by a reviewer with standing in the mathematics community although it is presumed if necessary it could be (I, unfortunately, know of cases where a paper has been reviewed approvingly and then later found to be flawed and withdrawn). Further,arguments of proof have themselves been debated as to their logical standing over time (proof by contradiction is one such). Nonetheless, mathematicians do see, as Andy noted, a world of mathematics with necessary and sufficient relations. Children, in the K-12 mathematics curriculum (immersed in text created by mathematicians and like-minded) may well be a different matter.

       Carol, I am fine if you post this conversation. My historical contributions were a little hurried and I glossed over exact dates and probably too quickly interjected details. I am certain that those with an eye for such things will notice mistakes and I apologize in advance. I have also have noticed the K-8 curriculum seeming as if ontogeny is recapitulating phylogeny. This raises large questions for me as it took smart men and women a long time to make the leaps which are, in effect, now tacitly presumed. One conclusion I have come to is that children are very, very intelligent (smile). Another is that  the standard mathematics curriculum may be a little outworn.


Ed

On Oct 30, 2014, at  4:34 AM, Andy Blunden wrote:

It's up to you, Ed.
I was fascinated with your maths history that Carol shared with me. I learnt about the history of mathematics at some point in my undergraduate life, but it is all a long time ago now, and I too found your observations quite engaging.
I don't know at what historical point, mathematicians began to get interested in mathematical relations without regard to any conclusions being drawn from them about the material world itself. But I would be interested to know. And I presume you, Ed, understood this distinction at the time our xcma discussion broke off.

Andy
------------------------------------------------------------------------
*Andy Blunden*
http://home.pacific.net.au/~andy/


Carol Macdonald wrote:
Hi Andy  and Ed again

I really think this is a very important distinction.  Between you and Ed, guys I urge you to copy these messages to XMCA.  They seem to be significant contributions - principles - that we take us a good step further in our discussion on the listserve.

If you want me to do this for you, please let me know.

Best
Carol

On 30 October 2014 08:32, Andy Blunden <ablunden@mira.net <mailto:ablunden@mira.net>> wrote:

  Just thinking ...
  There is an important distinction between the objective validity
  of any application of mathematics, and the objective validity of
  mathematical processes themselves. Propositions about the real
  world established by mathematics are always, at best, relative
  truths. But the world of mathematics is no social convention in
  itself, but necessary relations.

  Andy
  ------------------------------------------------------------------------
  *Andy Blunden*
  http://home.pacific.net.au/~andy/
  <http://home.pacific.net.au/%7Eandy/>


  Carol Macdonald wrote:

      Read this Andy - it's totally intriguing.  I asked Ed to post
      it on the listserv. It seems it it ontogeny reciplating phylogeny.

      Carol ---------- Forwarded message ----------
      From: *Ed Wall* <ewall@umich.edu <mailto:ewall@umich.edu>
      <mailto:ewall@umich.edu <mailto:ewall@umich.edu>>>
      Date: 29 October 2014 19:53
      Subject: Re: Apologies
      To: Carol Macdonald <carolmacdon@gmail.com
      <mailto:carolmacdon@gmail.com> <mailto:carolmacdon@gmail.com
      <mailto:carolmacdon@gmail.com>>>


      Carol

              As I started to answer, I realized that my reply would
      need to be a little more complicated than I had realized (so
      as I am writing I am thinking it through). Part of the problem
      is that I have been talking with Andy about converting
      'real-life' into something symbolic on, in a sense, an
      'advanced' level (for instance, physics or engineering).
      However, the very use of number is a converting of 'real-life'
      into symbols and that happened very early in a pictographic
      sense. This means, in a certain sense, the mathematics that
      happens now early on in schools and on the playground mirrors
      in an operational sense (as versus a social sense) what
      happened very early in history.
             Something happened around 400 - 300 BC (there are
      indications the it had been percolating for awhile) in how
      mathematics was viewed. Up until l that time mathematics -
      which was most usually  for commerce and calendars - was sort
      of done by recipes. People noted that if you did this and that
      you would get accepted answers, but arguments about 'validity'
      usually were of the form, "If you get some other answer, show
      me and I might believe you." Answers hinged on, on might say,
      the personal authority of the 'scribe' or 'teacher' (again
      reminiscent  of what goes on in schools today). Anyway, about
      300 BC Euclid published his Elements. This was, one might say,
      a geometric algebra, but more importantly, arguments within
      this work had a certain absolute nature; that is, if you do it
      this way, it is right no matter what anyone says otherwise
      (i.e. the best way I can say it is that 'within' mathematics
      the social convention became that social conventions had no
      force as regards the arguments). This was very, very different
      than what had gone before and Aristotle was moved to say that
      essentially there was no connection between mathematics and
      'real-life' and physicists who tried to make some connections
      were just wrong (there were also a series of paradoxes put
      forth by Zeno around 400 BC that indicated there were problems
      with making direct connections - they still have really never
      been resolved).
            Well, Greek thinking of mathematics (some of which has
      been called, n part, a rhetorical algebra) slowly faded from
      the scene, and people largely went back to 'experimental'
      arguments as regards things mathematics. However, in Arabia
      some of that thinking was preserved and the was a sort of
      rebirth. According to the historical records a group of people
      engaged in what was termed al' gebar became active. These were
      people who basically were generating and recording
      mathematical 'recipes' and who had developed ways of moving
      back and forth between recipes doing what is now called a
      syncopated algebra). In about 780 AD one such person wrote a
      book termed roughly Completion and Balancing. It is unclear,
      again what happened, and whatever it was it was different than
      the Greek geometric algebra, but again accepted arguments were
      socially assumed to not be vested in personal authority. Also
      there wasn't really a symbolic notation, but abbreviations
      were used.
             This seems never to have really caught on. In Europe,
      until around the 16th century mathematics had roughly the
      status of authoritative recipes although syncopated algebra
      was beginning to catch on (the Arabic influence). Again
      something happened and certain people began to symbolize
      'real-life' somewhat as it is done in modern times. One of the
      principal thinkers was a Vičte. Drawing on the Greek Pappus
      (290 AD), he distinguished three stages (1) Find a equation
      between the magnitude sought and those given; (2) Investigate
      as to whether the equation is plausible; and (3) produce the
      magnitude. This might look for a word problem as follows: (1')
      hypothesize a series of operations to generate the answer;
      (2') check to see if this is reasonable (students don't always
      do this, but physicists, engineers, and mathematics tend to do
      this); (3') calculate the answer. Vičte also created a
      symbolic notation.

           It is argued by some that there are some problems in all
      this. That is, it may be the case that the modern mathematics
      that underlies the sciences limits, in a sense, access to
      'real-life. I have been wondering - since the
      social/historical leaps taken although not obvious in the
      curriculum,are tacitly assumed in texts and by teachers -
      whether some of this (i.e. the leaps) may be limiting the
      access  to mathematics instruction. It is as if we are
      exposing children to a mathematics which operationally
      resembles that practiced long ago, but expecting them to
      'leap' to a view of mathematics that tacitly underlies the
      mathematics of today. I apologize for not being clearer, but I
      am yet working these ideas through.

      Ed

      On Oct 28, 2014, at  3:16 AM, Carol Macdonald wrote:

      > Ah Ed
      >
      > Now you do need to explain that to me - that's no doubt the
      heart of the matter.
      >
      > Carol
      >
      > On 27 October 2014 20:26, Ed Wall <ewall@umich.edu
      <mailto:ewall@umich.edu> <mailto:ewall@umich.edu
      <mailto:ewall@umich.edu>>> wrote:
      > Carol
      >
      >       If I understand what you mean by the conversion, it is
      quite interesting. There is a historical sense in which the
      possibility in the pre-modern times seems to have been
      realized twice. Now, it is, perhaps unfortunately, taken for
      granted.
      >
      > Ed
      >
      > On Oct 27, 2014, at  2:43 AM, Carol Macdonald wrote:
      >
      > > Ed, I see I repeated what you said - it was in the other
      conversation. The conversion is the heart of the matter.
      > >
      > > Best
      > > Carol
      > >
      > > --
      > > Carol A  Macdonald Ph D (Edin)
      > > Developmental psycholinguist
      > > Academic, Researcher,  and Editor
      > > Honorary Research Fellow: Department of Linguistics, Unisa
      > >
      > >
      > >
      > >
      >
      >
      >
      >
      > --
      > Carol A  Macdonald Ph D (Edin)
      > Developmental psycholinguist
      > Academic, Researcher,  and Editor
      > Honorary Research Fellow: Department of Linguistics, Unisa
      >
      >
      >
      >




      --         Carol A  Macdonald Ph D (Edin)
      Developmental psycholinguist
      Academic, Researcher,  and Editor Honorary Research Fellow:
      Department of Linguistics, Unisa



--
Carol A  Macdonald Ph D (Edin)
Developmental psycholinguist
Academic, Researcher,  and Editor Honorary Research Fellow: Department of Linguistics, Unisa