# Possibly Stupid Question on Atom Smashing

1. Apr 16, 2012

### Willard37

Suppose you theoretically have two betatrons each accelerating a particle near light speed in opposite directions. Suppose you collide both of these electrons together head on both at close to light speed. Since the collision is happening at speeds over the speed of light, does anything peculiar happen? Sorry if this sounds completely outrageous, Im brand new to physics.

2. Apr 16, 2012

### DrewD

The collision is not happening at a speed greater than the speed of light in the reference frame of either of the particles. A really quick search found this. Not much math, but seems intuitive.

I assume that is the reason that you thought the something peculiar would happen... although, a lot of peculiar things DO happen when particles are smashed together, but I'm guessing your worry was over the issues with relativity. If I'm wrong, I apologize.

3. Apr 16, 2012

### DaveC426913

Calculating relativistic velocities is not done in the way you'd expect. You use the Lorentz transform. It will always result in a velocity less than c.

4. Apr 17, 2012

### DrChinese

Welcome to PhysicsForums, Willard37!

As already mentioned, velocities do not add in a linear fashion (as in 1+1=2), although it appears that way when the velocities are very low. As you approach the speed of light, the difference becomes quite pronounced.

Keep in mind that experiments of the type you describe are done routinely.