[Phys-L] independent of mechanism

[John Denker <jsd@AV8N.COM>]

Rauber, Joel wrote:

> we have identified a situation (sticking collision) where a
> result is independent of the mechanism causing the sticking.

Yes!!!!!!!!!!

> Ie. this
> factor of 1/2 as analyzed in the lab frame is extremely robust.  I find
> this amazing and a bit perplexing, though true.  And I think that is
> where the question is coming from.

Ah, well, if that is the substance of the question, then it is
one of the all-time great questions.

   Amazing?  Yes.

   Perplexing?  Somewhat.

   Robust?  Yes, over a wide (but not infinitely wide) range of conditions.

   Magical?  It's waaay better than magic, because it's real.

   Unreasonable?  I'm not sure what that means, although I often hear the word
     used in this connection.

I would vehemently recommend not ducking this question.
We should revel in it.
This is the glory of physics, that we can say things that are
independent of mechanism.

This isn't about momentum per se. This isn't about energy per se.
This is about things that are independent of mechanism.

It is a treeeeemendous achievement that we can know energy is conserved
without necessarily knowing how (in any particular situation) the
energy is going to be conserved.

  -- Conservation of energy
  -- Conservation of momentum
  -- Paraconservation of entropy
  -- Conservation of lepton number
  -- Conservation of charge
  -- Conservation of each nuclide separately in ordinary chemical reactions
  -- Et cetera.

I have a story about this:
   http://www.av8n.com/physics/clock.htm
_______________________________________________
Phys-L mailing list
Phys-L@electron.physics.buffalo.edu
https://www.physics.buffalo.edu/mailman/listinfo/phys-l