Occam's razor and common sense

[David <dfrankiswork@netscape.net>]

I have been composing a reply to Grey Wolf's message 51793 on the 
main list, and part of it is definitely tangential.  Years of 
writing exams and proposals mean that I can't just throw away 
something once I have written it, so here it is.

Grey Wolf wrote:

> Occam's Razor doesn't work in books - and
> neither it does in Science, when you get right down to it. Quoting
> Terry Pratchett:
> 
> "Einstein published Special Relativity in 1905 ... the conclusion 
was
> that the universe is a lot weirder than common sense tells us,
> although they probably didn't use that actual word."
> 
> Some of the conclusions of Einsteins Theory of Relativity are
> flagrant breaches of "common sense" (on which Occam's Razor is 
based),
> like time being distorted by mass, and Time starting a few moments
> *after* the Big Bang (I still don't get that one myself).

Oddly enough, Einstein devised Special Relativity as a classic 
Occam's Razor response to experimental evidence (the Michelson-
Morley experiment) which forced Newtonian ether-based theories into 
ever less credible complexity and special pleading.  He theorised 
that the speed of light is the same no matter what speed the 
observer is travelling,  a counter-intuitive but very *simple* 
hypothesis from which all the other counter-intuitive conclusions of 
Special Relativity flow.

IMO, common sense is *never* simple.  That is why it is common.  It 
is the collected wisdom of a culture that is rarely questioned by 
its members.  Different cultures can have radically different ideas 
of what constitutes common sense.  In many cultures, it is common 
sense that you don't take food out of your family's mouth to pay 
taxes to the state.  In others it is common sense that the 
collective enterprise of the people demands a collective sacrifice 
of resources.

David