Changes

: Number 4: for mass that is infinitesimally small, its momentum goes to infinity under Relativity as its speed approaches the speed of light.  But this is absurd because if the mass is precisely zero rather than infinitesimally close to zero, its momentum is finite at the speed of light.--[[User:Aschlafly|Andy Schlafly]] 12:05, 10 August 2010 (EDT)

: Number 4: for mass that is infinitesimally small, its momentum goes to infinity under Relativity as its speed approaches the speed of light.  But this is absurd because if the mass is precisely zero rather than infinitesimally close to zero, its momentum is finite at the speed of light.--[[User:Aschlafly|Andy Schlafly]] 12:05, 10 August 2010 (EDT)

:: Are you sure that this is true? What are you fixing? One formula for relativistic momentum is <math>dp=\gamma v\left( dm \right)</math>. This remains a differential quantity in <math>m</math> as velocity becomes infinite. Fixing energy gives the correct momentum result in the limit as velocity becomes infinite. Maybe the misunderstanding results from taking two limits at once -- the prefactor that depends on velocity becomes infinite while the rest-mass dependence remains linear. [[User:TylerGD|TylerGD]] 13:28, 10 August 2010 (EDT)

:: Are you sure that this is true? What are you fixing? One formula for relativistic momentum is <math>dp=\gamma v\left( dm \right)</math>. This remains a differential quantity in <math>m</math> as velocity becomes infinite: <math>\left. \frac{dp}{dm} \right|_{v\to \infty }</math>. Fixing energy gives the correct momentum result in the limit as velocity becomes infinite. Maybe the misunderstanding results from taking two limits at once -- the prefactor that depends on velocity becomes infinite while the rest-mass dependence remains linear. [[User:TylerGD|TylerGD]] 13:28, 10 August 2010 (EDT)