Welch certainty principle continued

A method of determining through which slit of a double slit system a particle passes in formation of an interference pattern comprising the steps of:

• a) providing a double slit system which comprises:
• a′) a source of particles;
• a″) a barrier having two slits therein;
• a′″) a screen;
• such that in use a particle is caused by said source thereof to approach and pass through a slit in said barrier, then impinge on said screen;
• and such that when a multiplicity of particles are so caused to pass through one or the other slit in said barrier, then impinge on said screen, an interference pattern emerges, said interference pattern having positive and negative slopes on both sides of a center point of said interference pattern;
• said screen further having means for allowing lateral motion in response to momentum transfer from an impinging particle;
• b) causing said source to project a particle toward said barrier such that it passes through one of the slits and impinges said screen in a manner allowing the position at which is impinges to be identified, as well as how far said screen moves laterally in response to momentum being transferred thereto;
• said method further comprising
• c) determining that for particles contributing to positive slope regions in the interference pattern to the right of said interference pattern central region and for particles contributing to negative slope regions in the interference pattern to the left of said interference pattern central region that the screen lateral motion is greater than for particles contributing to negative slope regions in the interference pattern to the right of said interference pattern central region and for particles contributing to positive slope regions in the interference pattern to the left of said interference pattern central region;
• and
• concluding therefrom that on both sides of the central region of the interference pattern, particles contributing to positive slope regions predominantly pass through the left slit and that particles contributing to negative slope regions predominantly pass through the right slit, said systems right and left being as viewed from said source.