1. Apr 5, 2016

### idea2000

When a collider such as the lhc accelerates two protons side by side, would thy seem to gain mass and then distort st? And if so, would the lab frame see them attract each other? How would the attraction be explained from the perspective of each particle, if they don't see the other particle gain mass?

2. Apr 5, 2016

### Staff: Mentor

No. The energy of an object is frame-dependent; but the gravity produced by an object is not.

No.

3. Apr 5, 2016

### idea2000

So when thy are accelerated, they gain mass, but, they don't distort st?

4. Apr 5, 2016

### idea2000

When protons collide, do they create new particles that distort st? And, do protons distort st the same way whether they are moving or at rest?

5. Apr 5, 2016

### Staff: Mentor

No. They gain energy with respect to the lab frame, but energy is frame-dependent. (Some old texts use the term "relativistic mass", but that is really just another name for energy.)

The source of gravity is not mass. It's the stress-energy tensor, which includes energy, momentum, pressure, and other stresses, in a way that ensures that the gravity produced by an object is frame-independent.

6. Apr 5, 2016

### Staff: Mentor

They can, yes.

The spacetime curvature produced by protons, or any other particles produced in accelerator experiments, is negligible.

Yes, because "moving" and "at rest" are frame-dependent, and as I already said, the gravity produced by an object (i.e., the spacetime curvature produced) is not frame-dependent.

7. Apr 5, 2016

### idea2000

When protons collide, does all that extra energy they have become converted into new particles who's total rest mass is greater than the rest mass of the two protons before they were accelerated?