Subject: Why can't you reach absolute zero as said by thethird law of thermodynamics

I know that the third law of thermodynamics states that a pure solid 
crystal at absolute zero has zero entropy but I don't see why this means 
that you can't reach absolute. I know that the entropy of a system must 
always increase but if the entropy used to fire the lasers at the atoms 
trapped in magnetic fields is greater than the entropy that the atoms had 
to start with then the entropy of the system would have increased and the  
entropy of the atoms would be zero and therefore we would have a 
temperature of absolute zero. Is the answer to this question something 
similar in concept to why the speed of light can't be reached (since mass 
increases to infinity and therefore you need infinite energy to travel at 
light speed - which is impossible)? Thanks

Re: Why can't you reach absolute zero as said by thethird law of thermodynamics