Creating a black hole with any mass?

[Nickj800]

If you can some how accelerate any starting mass closer and closer to the speed of light, can the mass become so great that it will form a black hole?

[Bill_K]

No, it's the rest mass that counts. And the rest mass of an object is always the same, no matter how fast its going.

[JesseM]

If you can some how accelerate any starting mass closer and closer to the speed of light, can the mass become so great that it will form a black hole?
See this entry (http://math.ucr.edu/home/baez/physics/Relativity/BlackHoles/black_fast.html) from the Usenet Physics FAQ (http://math.ucr.edu/home/baez/physics/). Also some posts from pervect on the gravitational field from an object moving relative to the observer here, here, and here.

[Bill_K]

Pervect's discussion starts off by saying that a moving object increases in mass and flattens out. He then goes on to talk about 'transverse mass' and 'longitudinal mass'. Well. Forgive me for saying so, but the concept of relativistic mass is outmoded and misguided, and it is startling to encounter it. It is precisely what leads to the confusion between formalism and physical reality illustrated by this current question.

It's a simple exercise to apply a Lorentz transformation to the Schwarzschild solution, and an even simpler one to realize that nothing unusual happens.