Re: [Phys-l] interaction pairs (was: ? passive force)

[John Denker <jsd@av8n.com>]

On 07/19/2007 05:53 PM, Paul Lulai wrote:

> I've recently switched from action/reaction to interaction pairs. 

That makes a tremendous amount of sense.

>  A
> switch in reference frame might change which is perceived as the
> action & which is the reaction.  Action/reaction also tends to imply
> one of the objects 'caused' the phenomena to occur while the other
> was an innocent bystander.  This is obviously not true.

I agree that misplaced notions of cause-and-effect are widespread
and troublesome.
  http://www.av8n.com/physics/causation.htm
 
> If we discuss every such occurrence as an interaction, the 'fault' of
> the collision is gone.  It is easier to see which objects are
> interacting (while easier, I'll admit it doesn't magically &
> completely remove the conceptual issue).  It is also a bit smoother
> when discussing impulses.  Stating that impulse-momentum methods work
> when we are interested in information just b4 or after an interaction
> is smoother than discussing action/reaction at that point.  It also
> allows an easy transition & reinforcement with N3L discussions than
> if I subbed in action/reaction or collision etc...
 
And ... it sets the stage for an easy segue to conservation of momentum.


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