How Much Light Energy Change Can Cause the Variation of Radin’s Double-Slit Fringe?

Introduction: The existence and mechanism of mind-matter interaction, which is sometimes termed psychophysical effect, is fundamental to our understanding of the physicality and causality of the entirety of phenomena that are amenable to experimental investigation. Recent reports (Radin et al., 2012; 2013) on variations in the fringe visibility of the interference patterns of laser-engaged double-slit experiments, which seemed inexplicable in the absence of psychophysical influences, have elicited notable debates within the scientific community and substantial interest among the lay population. In accounting for the observed changes of fringe pattern, Radin et al. reported that the electrical field of the light passing the two slits might have reached an asymmetry of 3:1 when under the psychophysical intent in comparison to the generally symmetric baseline. However, a change to the double-slit interference fringe could have multiple causes. The objective of this research is to investigate, by computer simulations, which kinds of physical variation could have led to the changes of the double-slit interference fringe as reported by Radin et al.  

Hypothesis: We theorize that a change to the double-slit interference fringe-pattern, or equivalently the fringe visibility, that is comparable to the level reported by Radin et al. could very well be caused by a slight asymmetry of the spectral bandwidth of the light passing the slit, subject to psychophysical intent. 

Methods: We implement computer simulations of double-slit fringe pattern based on the Huygens-Fresnel principle, using the primary experimental geometrical parameters of Radin et al. to assess how an asymmetry of the double-slit configuration could affect the fringe visibility. The computer simulation outcomes are validated against the well-known results of single-slit research, as a function of the slit width or slit opening, and symmetric double-slit research, as a function of the slit separation and slit width (or slit opening). Subsequently, we assess how an asymmetry in the physical size properties (slit width and the lateral offset of the slit center) and the photonic/spectral properties (intensity, wavelength, and spectral bandwidth) between the two slits would affect the fringe pattern. The asymmetry is realized by changing a respective property of one slit only. Fourier transformation of the double-slit interference fringe is also conducted, to infer subtle differences between fringe patterns that may be grossly less distinguishable.  

Results: The main result is that the normalized interference fringe corresponding to the asymmetry of the electrical field of 3:1 or 1/3:1 is grossly indifferent from that caused by an asymmetry of the spectral bandwidth of 0.00205nm between the two slits at a center wavelength of 632.8nm. A spectral broadening of 0.00205nm centered at 632.8nm would take approximately 3.64×10^(-6) times of the energy of reducing the electrical field of light of that slit to 1/3 to reach an effective 3:1 inter-slit ratio of the electrical field. This 0.00205nm spectral broadening of the light is estimated to associate with an energy change of no more than 10 picowatts for the experimental setting utilized by Radin et al.  

Discussion: This study has challenged the interpretation of the physical cause of the fringe pattern changes in the double-slit experiments of Radin et al when correlated with consciousness influence of unknown mechanism. Finding an alternative interpretation to the effect that takes just about 3.64×10^(-6) of the energy of that modeled by Radin et al will open new avenue of developing experimental approaches to target the energy-level mechanism of psychophysical effects. We also suggest one experimental configuration with adequate phase sensitivity to augment Radin’s double-slit to examine the occurrence of spectral broadening against the occurrence of intensity change in replicating the psychophysical experiments.    

By using computer simulation based on standard wave approaches to light, we demonstrate that the extent of the change to the double-slit fringe as reported by Radin et al can be caused by a spectral perturbation to the light, which would take only approximately 3.64×10^(-6) times of the energy change pertinent to the intensity change as was modeled by Radin et al.  This indicates that the intensity change as modeled by Radin et al was unlikely the physical precursor to the observed effect.