There was a real good comment re: antimatter in the book, Things in Which it is Impossible for God to Lie---Cant remember page or exact statement
here is a statement from anther pub:
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w604/1p.219Part35:"YourWillBeDoneonEarth"***25
Studies have been made of the effect of cosmic rays on living cells in animal bodies, particularly with respect to disorders of the mind. What effect do they have or will they have on the way men behave here on earth? Certainly the Creator of cosmic rays, Jehovah God, could use these to affect the minds of his enemies, including the king of the north and the king of the south, and could drive them to mutual slaughter: "every man’s sword shall be against his brother." (Ezek. 38:21, AS) In this prophecy God warns that he will also use other natural forces that are at his disposal, possibly a rain of antimatter that has the property of annihilating any material thing that it meets. He warns all scoffers that he will do an ‘unusual work.’—Isa. 28:21.