I tell you what gfm. To prove that impaction works I will make a bet with you. I will give you a marshmallow gun that can fire 40 feet with 100 small marshmallows about 1/2" in size. Then I will construct a 'mask' using 3 layers of chain link fence with the fences 2" apart.. All the holes will be 1-7/8" or larger. Then you stand 5' away from the first fence. I will give you $50 for every marshmallow you get through the 3 fences. You will give me $15 for every one you don't get through all three fences. Are you willing to take the bet? If you are correct, it should be an easy $5,000 for you. If I am correct, I will make at most $1,500. But based on the way impaction works, you will lucky get about 12% of the marshmallows through the 3 fences. This is simple physics that you seem to want to deny.