Subject: Any experimental evidence to prove that mass increases with speed?

Hi!  It's my understanding that accelerating a vehicle (or any massive object) 
to or past the speed of light is not possible.  As I understand it, as the 
vehicle accelerates, its mass increases; and as it approaches the speed of 
light, its mass becomes infinite.

However, I disagree with this belief.  I am curious as to whether anyone has 
ever conducted an actual experiment to verify that this increase in mass 
actually occurs.

I did some checking, and determined that the fastest object ever accelerated by 
man was a 1/10 gram object accelerated to 50 miles per second by a rail gun at 
Sandia Labs.  (If they've gone faster, they're not talking... at least, not to 
me.)  I don't know whether that speed would be fast enough to actually measure 
such a change, and whether a measurement could be taken at all under such 
conditions.  And I recall the Helios II satellite in the 1970's got up into 
similar speed ranges as it skimmed past the Sun.  Again, I don't know if an 
experiment could be conducted to measure mass change under those conditions.

So.  Any solid observational evidence to support the idea that mass increases 
with speed?

Thanks, Charlie

Re: Any experimental evidence to prove that mass increases with speed?