Hi its me again, sorry for my ignorance of physics. Anyways, I was reading on the net about how an objects mass increases as it approaches the speed of light thus making further acceleration rather hard. My question is this, we have been accelerating electrons for years now and have gotten them pretty close to the speed of light in particle accelerators. What is the practicle effect of this acceleration. Why doesnt that electron gain an enormous amount of mass and burst through the walls of the particle accelerator? Thanks.