Look at the Higgs Boson. From my understanding of it, it is responsible for giving things mass. Imagine what we could do if we could manipulate the mass of objects. The ability to reduce the mass of a spaceship would make long distance space travel less difficult. The ability to alter the mass of an object could protect the Earth from asteroids and rogue planets. In a more mundane situation, imagine being able to change the weight on your weight bench by turning a dial and altering the mass of the weights on the barbell.