# Particle accelerator?

1. Oct 1, 2007

### Holocene

Particle accelerator???

I've read that we have accelerated small particles to 99.99% the speed of light.

Now, if I understand this correctly, a particles mass increases as its speed increases.

Also, if an object "having mass" was moving at the speed of light, it would have infinite mass, and therefore would require infinite energy to accelerate it to the speed of light, and since infinite energy does not exist, this is why anything having mass cannot reach light speed.

So my question is, how much more massive is small particle when it is moving at 99.99% light speed?

It seems like if it was so close to actual light speed, its mass would be huge, perhaps as much as the earths, and accelerating an object that close to light speed could knock the planet right out of orbit or something?

2. Oct 1, 2007

### bravernix

It seems to be a good idea (and is increasingly more popular) to just ignore the idea of relativistic mass altogether. You may want to find a book that describes relativity in terms of 4 vectors, such as Griffiths E&M (ch. 12 I believe).

3. Oct 1, 2007

### cesiumfrog

Assume the particle was a proton. Come back once you've done the (trivial) maths and compared the numbers.