Many mouse clicks
> Intuitively, I would also think that two objects colliding at 450 each would equal a closing speed of 900 GeVs, but doesn't the theory of relativity contradict this, and suggest it's still 450?
Nope, the 450 GeV is a measure of energy, not velocity. Of course, in an accelerator, the two are correlated. As the energy goes up, the velocity gets closer and closer to the speed of light (but never actually to it).
With regards to it 'being a few mouse clicks' away. If only... There are many issues here. Firstly, we have only had one bunch of protons in each beam wanging around. When running at full tilt, there will be just under 4000 bunches per beam. We also need to fully commission the beam dump, beam cleaning (to avoid stray high-energy particles quenching magnets) system, feedback mechanisms that keep the orbits stable, make sure the response of all that is understood, etc etc etc and much more. This is all being done 'as we speak'. We're all hoping to crank up the energy-knob soon, but the machine needs to be understood first!