NIck Porcino writes "Warp drive one step closer to reality! From the abstract: A spacetime is presented for which the total negative mass needed is only the order of grams, accompanied by a negligible amoung of positive energy. This constitutes a reduction of the absolute value of the energy by 65 orders of magnitude. The new geometry satisfies the quantum inequality concerning WEC [Weak Energy Condition] violations and exhibits the same advantages as the original Alcubierre spacetime. Read it here. The two big problems to be resolved are 1) how do you get an object inside a warp bubble? 2) What happens to the object when the warp bubble collapses? "