[Phys-L] definition of 3-velocity

[John Denker <jsd@AV8N.COM>]

In another thread Bob Sciamanda wrote something that
> Apply JD's analogy to the momentum-energy four vector of a particle.  In its
> proper frame its 3-momentum and 3-velocity are zero.  In another inertial
> frame, it has non-zero 3-momentum/velocity.  This spatial component of the
> momentum-energy four vector is merely a projection (a shadow) of the
> magnitude invariant 4-vector upon the space axes of the new frame.  It must
> follow, by the JD analogy, that the particle is not really moving.
>
> Bob Sciamanda
> Physics, Edinboro Univ of PA (Em)
> http://www.winbeam.com/~trebor/
> trebor@winbeam.com
>
>
> .
_______________________________________________
Phys-L mailing list
Phys-L@electron.physics.buffalo.edu
https://www.physics.buffalo.edu/mailman/listinfo/phys-l