If a particle collides with an anti-particle, should it give -1 + 1 = 0? Therefor, would 0 = -1 + 1 be reasonable? Is it possible that it in fact can be reversed. I will study in year 12 / form 6 in September, so you see, my knowledge of science is very small, I am only interested. I am a student, so sorry if I seem ignorant.