Abstract Ð An experiment in which participants were asked to reduce the fringe contrast in a Young’s double-slit interference pattern has been conducted independently at two laboratories using the same apparatus. Participants at York University were explicitly invited to exert their intentionality either to direct the photon flux preferentially through one path or the other, or to obtain spatial information about the division of the flux. Participants at Princeton University were invited simply to reduce the fringe contrast by any strategy they wished. Results from both laboratories (Z =- 0.481 and Z = 1.654 respectively) are discussed along with a description of earlier efforts to frame this experiment as a test of an extra-sensory channel for the acquisition of information.
Abstract Ð An experiment in which participants were asked to reduce the fringe contrast in a Young’s double-slit interference pattern has been conducted independently at two laboratories using the same apparatus. Participants at York University were explicitly invited to exert their intentionality either to direct the photon flux preferentially through one path or the other, or to obtain spatial information about the division of the flux. Participants at Princeton University were invited simply to reduce the fringe contrast by any strategy they wished. Results from both laboratories (Z =- 0.481 and Z = 1.654 respectively) are discussed along with a description of earlier efforts to frame this experiment as a test of an extra-sensory channel for the acquisition of information.
Motivated by a series of reported experiments and their controversial results, the present work investigated if volunteers could causally affect an optical double-slit system through mental efforts alone. The participants' task alternated between intending the increase of the (real-time feedback informed) amount of light diffracted through a specific single slit and relaxing any intention effort. The 160 data sessions that 127 volunteers took part in revealed a statistically significant 4.68 sigma difference between the measurements performed in the intention versus the relax conditions (p=2.93×10−6;es=0.47±0.20 95\% CL), while the 160 control sessions conducted without any observers present resulted in statistically equivalent samples (z=0.35,p=0.73;es=0.04±0.20 95\% CL). The results could not be explained by environmental factors, hence supporting the previously claimed existence of a not yet understood form of interaction between a conscious agent and a physical system.
Lay Summary Whether and how consciousness could affect a physical system is a fundamental question. Radin et al (Radin et al 2012, 2013) reported that consciousness could perturb the fringe pattern of the classical experiment of double-slit illuminated by a laser beam. In understanding the possible physical cause to the observed change of the fringe, Radin et al modeled that the light intensity passing a slit subjected to consciousness intention could have changed. 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 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 was unlikely the physical precursor to the observed effect. Scientific Abstract Significance: Recent reports [Radin 2012, Radin 2013] on variations to the fringe visibility of the interference patterns of laser-engaged double-slit experiments that seemed inexplicable at the absence of psychophysical influences have elicited notable debates within the scientific community and substantial interest in the lay population. In accounting for the observed changes of fringe pattern, Radin et al. modeled that the electrical field of the light passing the two slits might have reached an asymmetry of 3:1 in comparison to the generally symmetric baseline. However, a change to the double-slit interference fringe could have multiple causes. Identifying the most plausible cause to the fringe-pattern changes as were reported is fundamental to the understanding of the nature of psychophysical effect should it exist. Aim: To theorize an alternative interpretation to the fringe pattern changes of the double-slit interference that could be substantially more plausible than the one conjectured by Radin et al. Approach: 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. Specifically, 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. Fourier transformation of the double-slit interference fringe is also conducted when prompted to infer differences between fringe patterns that may be grossly equivocal in terms of the fringe visibility. 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 6328nm center wavelength. A spectral broadening of 0.00205nm centered at 632.8nm would take approximately times of the energy of reducing the electrical field of light of that slit to 1/3 to reach a 3:1 inter-slit ratio of the electrical field. This 0.00205nm spectral broadening of the light could be associated with an energy change of no more than 10 picowatts for the experimental setting utilized by Radin et al. Conclusions: A change to the fringe pattern in the double-slit of Radin et al that was fitted with a 3:1 asymmetry of the electrical field between the two slits could be modeled alternatively by an asymmetry of ~0.00205nm in the spectral bandwidth between the two slits. The latter one, which would take approximately times of the energy-change of the former one to happen, could be substantially more plausible than the former one in acting as the physical precursor to the deviation of the double-slit fringe from the baseline pattern as reported by Radin et al.
Motivated by a series of reported experiments and their controversial results, the present work investigated if volunteers could causally affect an optical double-slit system by mental efforts alone. The participants' task in the experimental sessions alternated between intending an increase in the (real-time feedback-informed) amount of light diffracted through a specific single slit versus relaxing their intentional effort. In total, 240 sessions contributed by 171 volunteers were recorded. The first 160 sessions were collected in an exploratory mode, and those data revealed statistically significant differences between the intention and relax conditions. The analysis method and variables of interest derived from the exploratory sessions were then pre-registered for the subsequent 80 formal sessions. The formal experiments, based on a directional hypothesis, were not statistically significant. A post hoc meta-analysis based on a bi-directional hypothesis, and applied to the same data, resulted in a 2.75 sigma outcome (p=6.02×10−3;es=0.31±0.22 95\% CI). Directional and bi-directional analyses applied to an equal number of control sessions, all conducted without observers present, resulted in uniformly non-significant outcomes. Analysis of environmental factors did not reveal any artifactual sources that might have produced the significant bi-directional effect. While the pre-registered analysis did not support the existence of the investigated phenomenon, the post hoc findings warrant further investigation to formally test the bi-directional hypothesis.
It was recently proposed that the fringe visibility in the interference pattern of a double-slit diffraction experiment with a HeNe laser beam was reduced as a consequence of the focused attention of participants on the double-slit that initiated the collapse of the photon wavefunction. A thorough examination of the reported apparatus and diffraction pattern data is presented here revealing a number of inconsistencies in the experimental setup. The hypothesis for wavefunction collapse under the proposed experimental conditions is found problematic as the use of single photon sources is demanded.
To investigate von Neumann’s proposal that an “extra-physical process” is involved in the measurement of a quantum system, an online experiment was conducted using a double-slit optical system. In a counterbalanced fashion, participants focused their attention toward or away from a feedback signal linked in real-time to the double-slit component of an interference pattern. A line camera continuously recorded the interference pattern at 4 Hz, and for each camera image fringe visibility was determined for the central 20 fringes. During 2013 and 2014, a total of 1,479 people from 77 countries contributed 2,985 test sessions. Over the same period 5,738 sessions were run as controls by a computer programmed to simulate human participants. The results showed that with human observers the fringe visibility at the center of the interference pattern deviated from a null effect by 5.72 sigma (p = 1.05×10), with the direction of the deviation conforming to the observers’ intentions. The same analysis applied to the control data resulted in an overall deviation of -0.17 sigma. After consideration of alternative explanations, these results were found to support von Neumann’s conclusion that the mind of the observer is an inextricable part of the measurement process. This type of experiment offers a means of empirically resolving longstanding questions about the role of consciousness in the physical world. Resume: Pour examiner si le concept de von Neumann en mecanique quantique d'une interaction de nature « non-physique » est mieux interpretee comme une forme passive d'observation ou comme une influence active, une experience a ete menee sur Internet en utilisant un systeme optique a double fente. Dans un protocole contrebalance, les participants ont concentre ou non leurs attentions sur un signal representant en temps reel le niveau d’interference du systeme de double fente. Une camera enregistrait en continu le motif d'interference a 4 Hz, et pour chaque image, la visibilite d’interference des 20 franges d’interference centrales a ete calculee. Au cours des annees 2013 et 2014, 1479 personnes en provenance de 77 pays ont contribue 2985 sessions. Au cours de la meme periode 5738 sessions controles ont ete enregistrees par un ordinateur qui simulait un participant humain. Les resultats ont montre que la visibilite d'interference pendant les periodes de concentration
An experiment we conducted from 2012 to 2013, which had not been previously reported, was designed to explore possible psychophysical effects resulting from the interaction of a human mind with a quantum system. Participants focused their attention toward or away from the slits in a double-slit optical system to see if the interference pattern would be affected. Data were collected from 25 people in individual half-hour sessions; each person repeated the test ten times for a total of 250 planned sessions. “Sham” sessions designed to mimic the experimental sessions without observers present were run immediately before and after as controls. Based on the planned analysis, no evidence for a psychophysical effect was found. Because this experiment differed in two essential ways from similar, previously reported double-slit experiments, two exploratory analyses were developed, one based on a simple spectral analysis of the interference pattern and the other based on fringe visibility. For the experimental data, the outcome supported a pattern of results predicted by a causal psychophysical effect, with the spectral metric resulting in a 3.4 sigma effect (p = 0.0003), and the fringe visibility metric resulting in 7 of 22 fringes tested above 2.3 sigma after adjustment for type I error inflation, with one of those fringes at 4.3 sigma above chance (p = 0.00001). The same analyses applied to the sham data showed uniformly null outcomes. Other analyses exploring the potential that these results were due to mundane artifacts, such as fluctuations in temperature or vibration, showed no evidence of such influences. Future studies using the same protocols and analytical methods will be required to determine if these exploratory results are idiosyncratic or reflect a genuine psychophysical influence.