Re: CAUSATION IN PHYSICS

[John Denker <jsd@MONMOUTH.COM>]

At 04:59 PM 10/14/00 -0700, Leigh Palmer wrote:
> forces manifestly cause accelerations.

At 11:58 AM 10/15/00 -0700, Leigh Palmer wrote:
> In my physics it is evident, manifest, obvious, clear

At 09:10 PM 10/15/00 -0700, Leigh Palmer wrote:

> It is evident to many of us that there is a causal relation between force and
> acceleration.

1) Leigh, please clarify what you take as the definition of "causality" or
"causation".

2) Unless it is an obvious consequence of item (1), please verify you
consider it manifest (etc.) that
        accelerations do not cause forces

This verification is important because some people have stretched the
definition of causation to permit statements such as "forces cause
accelerations and vice versa equally".

> The fact that the relationship is not manifest in the mathematical
> expression of Newton's second law merely indicates that the description is
> incomplete.

Aha.  That seems to agree with half of what I've been saying, namely the
part that says F=ma is an equivalence, allowing F to be calculated in terms
of ma, and vice versa.

So is there some _other_ law that rectifies the incompleteness of F=ma by
introducing an asymmetry between F and ma?

> Of course a mathematical expression subsuming causality could be invented
> and applied here, but that is unnecessary for those among us who take the
> causal relation to be self evident.

In the absence of a mathematical statement, all we have is a qualitative
statement of Palmer's Fourth Law of Motion:
        forces cause accelerations and not vice versa

I wonder what are the measurable consequences of this law.  (If there are
no measurable consequences, Kuhn would say the law is not falsifiable and
therefore unscientific.)  I wonder how one would perform an experiment to
measure the consequences.