Re: [Phys-l] The "why" questions

[John Denker <jsd@av8n.com>]

On 11/28/2010 06:37 AM, ludwik kowalski wrote:
> Thinking about this again I realized that both scientific and deistic  
> terms are embeded in human languages. Actually, it is more than terms.  
> It is the idea of causality. 

I agree with both parts of that.  Yes, it is embedded in
human language ... and yes, it goes much deeper than that.

Human beings have an innate drive to understand "why".  It
is one of the things that makes us human.  In the language
of anthropology, it is a cultural universal, right up their
with clothing, incest taboos, and religion.  Details differ
from culture to culture, but everybody has some version of
this.

Once upon a time I looked into cause-and-effect from the 
anthropological perspective.  I remember one anecdote:
somebody asked the village shaman why Sammy fell and broke
his leg.  The answer was immediate:  "It turns out that
Sammy was wearing mismatched socks that day.  Let it be
a lesson to all of you:  If you do something like that,
something that disturbs the harmony of the universe, bad
things are going to happen."

In our culture, we have plenty of pundits who each day
tell us /why/ the stock market went up or down that day.
We have members of congress who insist we don't need to
worry about global warming /because/ of the promise that
God made to Noah.  And we have physics books that tell
us the mass accelerates /because/ of the force.

> The question "why" is equivalent to "what  
> is the cause" of this or that. 

Yes.

> We believe that natural events are  
> interrelated; 

Yes, events are interrelated.

> this is usually called the cause-and-effect principle  
> (or idea). 

No!  Sometimes the relationship between events is properly
called a cause-and-effect relationship ... and sometimes not!

For example, sometimes two events (A and B) are collateral 
consequences of some earlier cause, such that neither A is
the cause of B nor vice versa.

More relevant to this list is the fact that you really should
not interpret F=ma as a statement that F causes ma or vice
versa.  Neither comes before the other, and you can't have
either without the other ... so neither can be considered
the cause of the other.

  It has been suggested that in theory you could say F causes 
  ma *and* ma causes F.  This exhibits the correct symmetry.  
  OTOH almost nobody likes this suggestion.  All the witch
  doctors want the arrow of causation to run one way and
  not the other.

> A particular egg came from a particular hen and a  
> particular hen came from a particular egg.  The well known general  
> question--“what comes first ...--” makes no sense.

The chicken-and-egg question has been put to many of uses, 
some of which make more sense than others.  There is, for
instance, a reasonable question that could be asked about
the /first/ egg or the /first/ chicken -- where did that
come from?  This illustrates the idea that proximate cause
is not necessarily the same as root cause.

It also serves to illustrate the perils of circular arguments.
Many attempts to assign an arrow of causation to the laws of
physics wind up being circular (and/or inconsistent).

OTOH phrasing the question in terms of chickens as a class
and eggs as a class is not particularly useful.

Perhaps more to the point, the question about chickens and
eggs does not shed much light on whether F causes ma or
vice versa.

> Do you agree? Why  
> should it force us to stop asking the  “why” questions?

You can ask whatever questions you want.  You may or may
not get good answers.

In any case, the fact remains:  The laws of physics must
say what happens.  They may or may not say how it happens. 
The fundamental laws rarely if ever say /why/ it happens.

If you really want somebody to tell you /why/ it happens, 
ask a witch doctor or a TV commentator or Congressman
Shimkus or Senator Imhofe.  Don't ask a physicist.