# [Xmca-l] Re: Objectivity of mathematics

```I suspect there are a range of notions of objectivity at play here.

Just to (help?) clear up on a few issues.  We can see that statements such
as "the earth is round" are a social convention in the sense that:

i) It is a social convention to consider that the earth is a discrete
object that begins and ends at various relative points.  Is the earth the
beautiful blue and green thing that reflects light and is seen from space?
Does the earth include its magnetic and gravitational fields?  Is the
earth, in fact, not a ring wobbling around its star?  Or perhaps it is part
of some n-dimensional rubber-like sheet and actually flat?

ii) Mathematically construed shapes such as triangles, circles, ellipsoids
are conventions.  But these shapes also come with rigorous rules that
enable them to be related to each other.

iii) For many purposes it is very useful to consider that the earth
conforms to the convention called an ellipsoid.  If we didn't have this
conventional notion of an ellipsoid, we might say it was ball shaped or
round.

Perhaps folk can offer some examples of mathematical objectivity, e.g.
classroom dynamics, pure math, applied.

Best,
Huw

On 9 November 2014 00:18, Andy Blunden <ablunden@mira.net> wrote:

> Oh dear! some times I despair of the possibility of communication.
> That the Earth is round is a social convention, but it is not *only* a
> social convention; it has a sound basis in material reality. That is to
> say, Julian, no amount of discoursing and activity can alter the fact that
> the world is round. The roundness of the Earth is also outside discourse
> and activity, even though it is made meaningful and known for us only
> thanks to discourse/activity.
> Driving on the right is subject to discourse/activity. In about 1968
> Sweden changed from left to right. RIght-hand driving is *only* a social
> convention.
> Simple, eh? I would have thought so.
> Andy
> ------------------------------------------------------------------------
> *Andy Blunden*
> http://home.pacific.net.au/~andy/
>
>
> Martin John Packer wrote:
>
>> And also that the earth is round is a convention! Go figure!
>> Martin
>>
>> On Nov 8, 2014, at 5:55 PM, Julian Williams <julian.williams@manchester.
>> ac.uk> wrote:
>>
>>
>>
>>> I'm struggling to keep up here... Surely I didn't hear Andy Blunden say
>>> that 'objectivity' implies stuff that can't be transformed? I'm sure I must
>>> have misremembered that!.?
>>>
>>>
>>
>>
>>
>>
>>
>
>

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