🚀 go-pugleaf

In article <1992Nov2.043143.24298@augean.eleceng.adelaide.edu.AU> 
  dabbott@augean.eleceng.adelaide.edu.AU (Derek Abbott) writes:
>Imagine you are a stone age philosopher. All you have are your big chunky
>stone tools to work with to engineer with for everyday life.
>
>You produce a persuasive argument that it is impossible to ever produce
>tools, machines and measurements that are accurate to within micrometers
>(or fractions of a camel's hair).

It is always a mistake to say that something is now and forever
technologically impossible.  Eventually you will be proven wrong.  This
is (I presume) what the caveman is doing.  Not having seen his/her argument
I can't tell.  The thing with QM and related topics is that now we are
finding things that are fundamentally impossible.  Getting out of the
Earth's atmosphere is just a matter of building a big enough engine.
Getting beyond the speed of light has very different limitations.

C Frog

In article <1992Nov2.043143.24298@augean.eleceng.adelaide.edu.AU> dabbott@augean.eleceng.adelaide.edu.AU (Derek Abbott) writes:
>Imagine you are a stone age philosopher.
>It is obvious to you that your coarse implements can't measure to any greater
>accuracy than they are already and so engineering to greater precision
>is philosophically impossible, by simple inductive reasoning.
>
>Where is the flaw in his argument?

There is none, given the premise.

If the question is "will science never progress?" then
the answer is always "no."

If the question is "have we exhausted the limits of
progress in the current forms of science?" then
the answer is "perhaps."

If the question is "in certain arms of what appear to
be extremely advanced realms of science, have we
exhausted the limits except to those who have only
begun to learn about the topic?" then the answer can
often be "most likely."

In all cases any attempt to place a limit on science
can be balanced by the certainty that there exist
scientific phenomena of which we have not learned
even their existence.

>Nevertheless, the argument is very powerful, especially in stone age times
>when there would be no immediate counter evidence.

But he'd never heard of metalworking.

>I'm wondering to what extent we are tricking ourselves with words
>(like the stone age man example did) today when we grapple with such
>philosophical mysteries as quantum mechanics, mind-body problem,
>determinism v. free will etc.

Not a lot, if we desire otherwise.

It is possible to fully integrate the extent of current
science into current philosophy.  It is also possible to
predict the value and effect of imagined extents of future
science on future philosophy.  It is always possible to
devise past science to examine past philosophy.

Unfortunately it's done most often from a position of
gross ignorance, and both the science and the philosophy
appear laughable.  Our stone-age philosopher is a creation
of our impression of his scientific frontiers; we may very
well be giving his intellect embarrassingly short shrift.
An example of which is that I can make an arrowhead of
obsidian with an edge much sharper--but not harder--than
any steel edge.

The only trick is the one we permit and believe.

				--Blair
				  "Some of us had never heard of COBE.
				   And then they got a PR man.
				   VOTE PONS/FLEISCHMAN IN '92!"

In article <1992Nov2.043143.24298@augean.eleceng.adelaide.edu.AU> dabbott@augean.eleceng.adelaide.edu.AU (Derek Abbott) writes:
>Imagine you are a stone age philosopher. All you have are your big chunky
>stone tools to work with to engineer with for everyday life.
>
>You produce a persuasive argument that it is impossible to ever produce
>tools, machines and measurements that are accurate to within micrometers
>(or fractions of a camel's hair).


A lovely counterexample to this is provided by the process of grinding
your own 6" mirror for a Newtonian reflector.  You start out with two
circular pieces of glass, and spend a great many hours walking round
and round grinding them together, checking the mirror's shape
occasionally with a simple optical setup that doesn't require any
high-accuracy components.  When you're done you have a mirror ground to
a highly polished paraboloid, "to within a fraction of a camel's
hair."  None of the tools used need have anything like that accuracy.
(It is true that you ordinarily do the grinding with meticulously
graded grit, but I would think one could do one's own separation
without fancy equipment by dropping what you have a long enough
distance to get the larger particles well below the smaller.  The key
thing is not have any large particles in with a lot of small ones; the
converse is ok.)

Another example is the resistor cloning problem.  Given an unknown
resistance R somewhere between 100 and 10K ohms, a Wheatstone bridge,
and a plentiful supply of 20% resistors of all 20% sizes (1, 1.5, 2.2,
3.3, 4.7, 6.8 between say 100 and 10K ohms), it is possible to clone R
to an accuracy of .1%.  That's 200 times more accurate than the
resistors you get to make it from, without using any equipment honed to
anything like that accuracy.  This is a cute exercise.
-- 
                                       |
Vaughan Pratt                          |                          ttarP nahguaV
Why do mirrors reverse words&not lettersrettel ton&sdrow esrever srorrim od yhW

dabbott@augean.eleceng.adelaide.edu.AU (Derek Abbott) writes:
>Imagine you are a stone age philosopher. All you have are your big chunky
>stone tools to work with to engineer with for everyday life.
>
>You produce a persuasive argument that it is impossible to ever produce
>tools, machines and measurements that are accurate to within micrometers
>(or fractions of a camel's hair).
>
>It is obvious to you that your coarse implements can't measure to any greater
>accuracy than they are already and so engineering to greater precision
>is philosophically impossible, by simple inductive reasoning.
>
>Where is the flaw in his argument?
>
Do you mean "flaws", perhaps?  First and foremost, the details of any 
such argument are irrelevant.  "Simple _inductive_ reasoning" will
not provide a proof of "philosophical impossibility."  If it was a
good argument, then the conclusion would only be more probable, not
proven.

The second point concerns the applicability of this analogy to 
quatum mechanics.  It's not.  The arguments involved for conclusions
such as "we cannot measure both the position and momentum of a
particle to arbitrary precision" are _deductive_.  It follows then
that the truth of the conclusion is based on the truth of the premises
*only*.  To my knowledge (limited, I'll admit) these premises are
true.  I open to corrections here.  

The final point is that new discoveries in physics do not contradict
previous findings.  For example, the discovery of relativity did not
invalidate Newtonian mechanics (if it did then I'm wasting alot of time
every monday and wednesday afternoon in class! :).  It did clarify
the circumstances in which classical mechanics provides a good
approximation (e.g. v/c << 1 ).  The flaw in the stone-age philospher's
argument is in looking for "the Truth."  Science typically looks for
good approximations with predictive power.  I expect that any new
advances in physics will not contradict Heisenberg's statements, they
may perhaps illuminate the conditions under which his principle 
applies. 

>
>Are we fooling ourselves? Comments?

Some of us are!  :)  (me too, on occasion).

..don...

dabbott@augean.eleceng.adelaide.edu.AU (Derek Abbott) writes:

: Imagine you are a stone age philosopher. All you have are your big
: chunky stone tools to work with to engineer with for everyday life.

First, Philosopher's should abstain from making engineering decisions
without any experience or education upon which to base such decisions.

: You produce a persuasive argument that it is impossible to ever
: produce tools, machines and measurements that are accurate to within
: micrometers (or fractions of a camel's hair).

And while you are producing persuasive arguments to the contrary,
other people are out actually doing it.

: It is obvious to you that your coarse implements can't measure to
: any greater accuracy than they are already and so engineering to
: greater precision is philosophically impossible, by simple inductive
: reasoning.

It may be obvious to you, but it's pure bullshit.

It's possible to measure and reproduce items accurate to within 100
microns using very primitive techniques.  Place two cubes against each
other and run you finger back and forth across the joint.  It's
possible to judge to within 20 or 30 microns which is larger.

If it's still too big, you get out the water and rouge and grind away
at it for another hour or two.  Talk to somebody who's ground their
own mirrors for a telescope -- a remarkably primitive but effective
process.

It's possible to determine if the corners of a large building are
level with nothing more than trenches in the ground and a few barrels
of water.

It's possible to layout an exact square with nothing more than a piece
of string.

People are patient and clever, Derek.  With a few thousand year's
worth of hard work they can accomplish quite a bit.

You have made the same mistake as do the "aliens built the pyramids"
crowd.  You have seriously underestimated the persistence and
resourcefulness of H. sapiens.

--
Grant Edwards                                 |Yow!  I just forgot my whole
Rosemount Inc.                                |philosophy of life!!!
                                              |
grante@aquarius.rosemount.com                 |

In article <1992Nov7.180042.18845@rosevax.rosemount.com> grante@aquarius.rosemount.com (Grant Edwards) writes:
>dabbott@augean.eleceng.adelaide.edu.AU (Derek Abbott) writes:
>
>: Imagine you are a stone age philosopher. All you have are your big
>: chunky stone tools to work with to engineer with for everyday life.
>
>First, Philosopher's should abstain from making engineering decisions
>without any experience or education upon which to base such decisions.
>
Second, engineers should learn the difference between plurals and possessives.
:-)

-- 
Christopher D. Green                christo@psych.toronto.edu
Psychology Department               cgreen@lake.scar.utoronto.ca
University of Toronto
Toronto, Ontario M5S 1A1