The Tractor Beam: Pulling Earth Out of the Fire

摘要: Star Trek has tractor beams that can push, pull, or hold an object in a steady position. Pushing and holding aren’t so hard to do, but emitting energy beam will draw toward the source of is quite trick. It seems like science fiction, scientists have developed several types true beams. Acoustic tractors aquatic use mechanical waves pull objects source, while negative radiation pressure laser manipulate cells small beads source. The are early efforts at producing Bessel beam, could push object, would reform itself behind any placed its path. These be very useful space as beams, although NASA’s upcoming manipulating asteroids comets rely on gravitational force between ship celestial object. gravity enhanced able move near-Earth out our way—if we begin enough.