Re: [Phys-L] Conservation of Energy vs Constant Energy

[Paul Lulai <plulai@stanthony.k12.mn.us>]

Thanks John.
I eventually stopped debating. I think it will come up again. I was shocked that energy conservation =/= energy is constant was a one vs the room debate. It seemed like some were slowly starting to wonder.
Baby steps i guess.
Have a good one, and thanks for the help.
Paul.


.:. Sent from a touchscreen .:.
                 Paul Lulai



-------- Original message --------
From: John Denker
Date:05/08/2015 6:53 AM (GMT-06:00)
To: Phys-L@Phys-L.org
Subject: Re: [Phys-L] Conservation of Energy vs Constant Energy

On 05/04/2015 07:51 AM, Paul Lulai wrote:

> I am in an awkward spot.  I am trying to convince a group of hs
> physics teachers that energy is always conserved.

Just now I upgraded my screed on this topic.
  https://www.av8n.com/physics/conservation-continuity.htm
or equivalently
  http://www.av8n.com/physics/conservation-continuity.htm

In particular, I added a new subsection and a couple of
new diagrams to explain why /locality/ is important, and
why locality requires us to think in terms of conservation,
not just constancy.
  https://www.av8n.com/physics/conservation-continuity.htm#sec-locality

I also made it somewhat less disorganized and fixed a
few typos.  The reasoning can be summarized as follows:

    * To be useful, the law must be local. Furthermore,
      special relativity says that a non-local law cannot
      possibly be correct.
    * Locality requires us to consider small systems.
    * Small systems are generally not closed.
    * Therefore a law that applies only to closed systems
      is nowhere near strong enough to be a fundamental
      law of physics.
    * The fact is, energy is /always/ conserved ... even
      in small, open regions where the energy is not constant.


--------------------------------
As a separate matter:

> Do folks have authoritative resources I can point to?

Rather than asking for an authoritative reference,
they ought to be asking for convincing evidence.

I know they're not scientists, and you're not going
to make them scientists overnight ... but you can at
least remind them that appeal to authority is risky
and unscientific.  It is very, very weak evidence.
  https://www.av8n.com/physics/authority.htm
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