Relativistic mass: real mass or mathematical concept

On Jun 2, 11:08 am, Amid wrote:

Does relativistic speed really increases the mass of a body?

The best interpretation to this is to treat mass as a observed
quantity mirroring that energy is an observed quantity as well.
shrug

Or is it
just a way to calculate particles at relativistic speeds.

shrug

I mean with this that if you send a particle at 0.99c does it attract
masses around it 7 times more?

Interestingly experimental results seem to indicate that the
gravitating mass is the rest mass of the gravitating body. shrug

It is most likely that mass does not have anything to do with
gravitation in which (G M) is merely a grossly simplified model
describing gravitation. shrug