Mass and the Speed of Light: Equations and Measurements

[ThoughtProces]

I was wondering if there is and what is the equations that show that as an object accelerates towards the speed of light its mass increase to infinite.

 

[jtbell]

You're probably thinking of this equation:

$$m = \frac {m_0} {\sqrt{1 - v^2 / c^2}}$$

 

[ThoughtProces]

i do believe this is the equation do you have a derivation of where it comes from or could you point me to a site for which it has the derivation.

thanks

 

[jtbell]

There was an extensive discussion here a couple of years ago, about the derivation of the relativistic mass:

https://www.physicsforums.com/showthread.php?t=153322

 

[ThoughtProces]

thanks for the link, it should prove to be a good read

 

[ThoughtProces]

I guess another question is how do we measure the initial mass of an object if we are all traveling at a changing velocity due to the constant acceleration of an expanding universe. Or is the initial mass relative to the expanding universe in its own frame of reference?