Felber's research shows that any mass moving faster than 57.7 percent of the speed of light will gravitationally repel other masses lying within a narrow 'antigravity beam' in front of it. The closer a mass gets to the speed of light, the stronger its 'antigravity beam' becomes. Oh??? If that is truly the case, one of the big barriers to FTL/near C travel vanishes. That was hitting individual atoms at that speed would generate a lethal shower of X-rays and secondary particles.