"Has Dawkins, Hitchens, Harris, or Grayling proved that God does NOT exist?"
What you can do is search for evidence of existence and where there is none one must conclude that what is being sought after is not real. Any entity that interacts with the universe, necessarily leaves material evidence of some sort. This evidence can be examined by science.
Because science doesn't deal with the supernatural the onus of proof is upon the believers. If i told you invisible talking spoons were flying around the place, i would have to prove it, science doesn't have to disprove it.
