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Re: [Phys-l] velocity-dependent mass (or not)



 It is true that relativistic mass is essentially relativistic energy. 
But it is also true that it can be independently determined as MASS
(measure of inertness - ratio of external force perpendicular to acceleration when the force is perpendicular to velocity) by an executable experimental procedure (e.g., from known charge, velocity, and radius of the circle traced out by a particle in a known magnetic field perpendicular to the plane of the circle).

Moses Fayngold,
NJIT


--- On Sun, 6/21/09, carmelo@pacific.net.sg <carmelo@pacific.net.sg> wrote:

From: carmelo@pacific.net.sg <carmelo@pacific.net.sg>
Subject: Re: [Phys-l] velocity-dependent mass (or not)
To: phys-l@carnot.physics.buffalo.edu
Date: Sunday, June 21, 2009, 9:30 AM

Quoting John Denker <jsd@av8n.com>:
  -- Should this notion be deprecated?
  -- Has this notion in fact been deprecated by professional
   relativists, for many many decades, i.e. throughout most of
   the history of the subject?
  -- Is this merely a question of taste, or is the vulgar notion
   of velocity-dependent mass provably and quantitatively wrong,
   especially when we consider something other than straight-line
   motion?
  -- How many more decades will it take before this trickles down
   to the introductory-level textbooks?

Electromotive force is not a force, displacement current is not really 
a current, and relatisitic mass, is in a sense, energy or mass 
depending on one's definition...

Will all these notion be deprecated? Perhaps, physicists enjoy the use 
of metaphor? :-)


Alphonsus


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