Re: the energy

[Bob LaMontagne <rlamont@POSTOFFICE.PROVIDENCE.EDU>]

*********** REPLY SEPARATOR  ***********

On 10/23/2004 at 3:15 PM Paolo Cavallo wrote:

I can stub my toe on a rock and it hurts. I can't stub my toe on
gravitational potential energy. I feel very comfortable calling one "real"
and one "fictional" or "abstract".

Bob at PC

> I agree that the difference is important, but I cannot find
> it relevant here.
> "Abstraction" is not the same as "fictional". *Any* concept
> in physics is an abstraction, not a "thing". It is (as in
> the much quoted Einstein) a human construct. But it
> describes reality as we experience it.
>
> "Reality" and "matter" are philosophical concepts, "mass"
> and "energy" physical ones. In physics we cannot say a thing
> about issues like "What is matter?" or "Is the world real?".
> We take the reality of the world for granted.
>
> (I wish I could tell it better, but my English is not as
> good as I would need.)
>
> (And, yes, I would like to know your operational definition
> of reality, too. I'm sure it's interesting.)
>
> ============================================================
> Paolo Cavallo                 " I am a teacher at heart, and
>                          there are moments in the classroom
>                           when I can hardly hold the joy. "
>                                        P. J. Palmer, 1998
> paolo.cavallo@iperbole.bologna.it
> http://paolo.cavallo.free.fr
> ============================================================