On 10 Feb., 18:59, Lester Zick wrote:
On Sat, 10 Feb 2007 12:05:22 -0000, "George Dishman"



wrote:

wrote in message
roups.com...

Hi Jim, long time no see.

A great enrager of Srians are mild questions about the energy (kinetic)
which vanishes
or miraculously appears depending on which "frame" they chose to place the
particle(s) in.

The same is true in Newtonian physics, the kinetic
energy of an object is zero in its rest frame
and the value diffes from frame to frame regardless
of what theory you use.

Nonsense, George. There is only one frame of reference in Newtonian
physics, a universal isometric Euclidean-Galilean-Cartesian-Newtonian
frame of reference whose origin can change but whose metric properties
remain constant unlike second order velocitiy dependent anisometric
properties of reference frames in SR. And that one universal frame of
reference is the reference frame against which all dynamic properties
such as momentum and energy are judged whether at rest or in motion.

Newton had the idea of absolute space and time.
However, even in Newtonian physics, the meaning of "here", "now" and
"motionless"
may differ from observer to observer, hence there /are/ different
frames of reference.
Recall e.g. how the description of a collision is simplified by
*choosing* *the*
*frame* *of* *reference* where the centre of gravity is at rest.
The impossibility to decide which frames rest relative to the absolute
space-time frame
(not to mention finding the origin of that frame) leads very naturally
to
the idea of abandoning absolute space-time and developing SR.