3.1 Interference of a Single Photon The kinds of study originally conducted by Thomas Young - in particular, the celebrated "double slit" experiment that we briefly examined in Chapter 1 (see Fig. 1) - provide a capacity to reveal far more than the wave nature of light, important as that is. True enough, the observed characteristic fringe pattern, when monochromatic light passes through two closely spaced slits onto a screen, appears to be simply explicable on the basis of waves from each slit undergoing constructive and destructive interference at different positions on the screen. Yet, astonishingly, these patterns of interference are still exhibited when individual photons of a low-intensity input beam reach the screen one at a time, showing that it cannot in fact be a matter of different photons having to interfere with each other. Indeed, Dirac enunciated the general principle that photons can never directly interact with each other. The double slit and other such experiments indicate that each photon interacts in a delocalized, wave-like manner with both slits at the same time. Successive experiments build interference patterns that conform to an exact mathematical distribution formula, but the position at which an individual photon is detected in any particular instance cannot be predicted; this is a quintessential illustration of quantum uncertainty. Using the path integral approach of quantum theory, the phenomenon is more accurately represented by introducing a summation over all possible routes between the source and the screen on which the pattern appears, signifying an entire "lifetime" for each photon involved in the experiment. This relates to the fact that the actual trajectory is unknown without an observation, and thus we only obtain the probabilities of the photon striking the screen at different positions and times; all trajectories (potentialities) must be considered in a superposition. Each route is considered equally probable, and the variation in phase produces quantum interference. The differences in phase of each trajectory, at varying positions on the screen, generates the fringe pattern. An intriguing variation on this experiment involves "marking" the photons so that the actual route of each photon to the screen is known. Remarkably, in such a case, the fringe patterns do not appear because quantum interference cannot occur. A consequence of the observation of the photon route is an effect that, in other quantum mechanical connections, is known as a collapse of the wavefunction. However, it is possible for the fringe patterns to reappear when information on the route of the photons is lost; this is known as a quantum eraser.
3.1 Interference of a Single Photon The kinds of study originally conducted by Thomas Young - in particular, the celebrated "double slit" experiment that we briefly examined in Chapter 1 (see Fig. 1) - provide a capacity to reveal far more than the wave nature of light, important as that is. True enough, the observed characteristic fringe pattern, when monochromatic light passes through two closely spaced slits onto a screen, appears to be simply explicable on the basis of waves from each slit undergoing constructive and destructive interference at different positions on the screen. Yet, astonishingly, these patterns of interference are still exhibited when individual photons of a low-intensity input beam reach the screen one at a time, showing that it cannot in fact be a matter of different photons having to interfere with each other. Indeed, Dirac enunciated the general principle that photons can never directly interact with each other. The double slit and other such experiments indicate that each photon interacts in a delocalized, wave-like manner with both slits at the same time. Successive experiments build interference patterns that conform to an exact mathematical distribution formula, but the position at which an individual photon is detected in any particular instance cannot be predicted; this is a quintessential illustration of quantum uncertainty. Using the path integral approach of quantum theory, the phenomenon is more accurately represented by introducing a summation over all possible routes between the source and the screen on which the pattern appears, signifying an entire "lifetime" for each photon involved in the experiment. This relates to the fact that the actual trajectory is unknown without an observation, and thus we only obtain the probabilities of the photon striking the screen at different positions and times; all trajectories (potentialities) must be considered in a superposition. Each route is considered equally probable, and the variation in phase produces quantum interference. The differences in phase of each trajectory, at varying positions on the screen, generates the fringe pattern. An intriguing variation on this experiment involves "marking" the photons so that the actual route of each photon to the screen is known. Remarkably, in such a case, the fringe patterns do not appear because quantum interference cannot occur. A consequence of the observation of the photon route is an effect that, in other quantum mechanical connections, is known as a collapse of the wavefunction. However, it is possible for the fringe patterns to reappear when information on the route of the photons is lost; this is known as a quantum eraser.
Quantum interference is a challenging phenomenon in quantum optics. According to this principle of superposition of quantum mechanics, elementary particles such as photon can not only be in more than one place at a given time, but that an individual particle can cross its own trajectory and interfere with the direction of its path. Thomas Young devised the double slit experiment to prove that light consisted of waves. Analysis of the double slit experiment and the interference pattern indicates that each photon not only goes through both the slits simultaneously, but traverses every possible trajectory on the way to the target, not just in theory, but in fact. In the present work we have analysed the situation in terms of quantum superposition and Schrodinger cat states in quantum optics. The nature of photon in this analysis is examined
Abstract Since it was born before its physical achievements, light waves, which have almost no physical properties, are an abstract mathematical concept rather than an objective description. Confused by a set of dark and light streaks and a sketchy schematic that had little to do with the actual result, the double-slit test was misjudged as being caused by interfering light waves, so this plausible principle implied disastrous flaws. For example, (1) Just after passing through the double-slit device, the pattern is generated by light early or before interference. By changing the distance between the device and the screen, the pattern is only scaled synchronously without being reconstructed by interference, and imagined light-wave interference does not occur. (2) Interfering light waves can be subdivided into multiple parts and proliferate greatly. (3) A headless wave of light left outside the screen after the head disappears can still induce much interference. (4) There is no interference effect caused by reflected light waves. (5) The effect of polarization direction on interference is neglected, and the interference condition is incomplete. (6) In the mathematical model, not only are the spots with the highest brightness in the position where dark stripes should appear most, but the principle of generating multiple regular dark stripes cannot be found. (7) Since the quantum property must be carried out in the process of interference, if all conditions are not met at the same time, interference will not be triggered, and therefore, the principle of interference will be rejected. (8) Since light comes only from the radiation of the electron transition, it is impossible to generate a light source in a slit that may be a vacuum. (9) In the causality test, to verify the effect of collapse, the photon that has collapsed into a particle should be tested again with a double slit test. (10) Whether the phenomenon of "observed tampering results" obtained by observation has been tampered with. (11) When the phase is shifted π or the signal is reversed, waves become negative waves capable of annihilating themselves, which is typical of antimatter. In this case, matter and antimatter are conjoined. (12) If the general law of waves is followed, not only the targeted light wave passes through the slit. (13) The original version of the double-slit test cannot be reproduced, and the test results are different from those presented by contemporary technology. (14) Waves must obey Fourier's principle, but light waves, quantum waves and matter waves do not. (15) The modulation effect that waves must produce is not present in optical fiber communication. (16) If the light from different slits must interfere with each other, a mask full of slits will cause the lithographer to fail. (17) Since the size is much smaller than the wavelength, the photon is only a sampling of the light wave, but the corresponding physical properties are not presented. (18) The fact that the two stars orbiting each other do not change color only proves that the phenomenon of redshift is impossible but does not support the inference that the speed of light is constant. (19) The Michelson-Morley test process is not open and transparent enough, and pinhole diffraction and mechanical processing using broken lines instead of curves cannot be ruled out. (20) Kepler's law can block Hubble's law and its derivatives, dark matter and dark energy. In conclusion, Newton's particle model was wrong, but neither was the light wave theory.
Abstract The double slit test, as it is known, results in a series of alternating streaks of light and dark, presumed to be caused by interfering light waves. Careful comparison of experimental results and mathematical models reveals that the plausible theory of light-wave interference contains many fatal flaws. For example, the mathematical model does not have a mechanism for regularly producing multiple dark streaks. In practice, the spot where the dark streaks should appear is the brightest spot. Since only the electron radiates photons outward as it lowers its energy and returns to its ground state, the photon waves generated in the slit (possibly a vacuum) are of unknown origin. When light waves interfere with each other, photons can be infinitely subdivided and multiplied; After the head of the photon reaches the screen, the rest of the photon can still participate in interference; The effects of reflected light waves that most satisfy the interference conditions are not shown in the fringe. The important influence of polarization direction is not considered in the interference condition. In the causality test, the photon that has collapsed into a particle should be retested with a double slit test. In the causality test, the photon that has collapsed into a particle should be retested with a double slit test. The phenomenon of "observation determines outcome" has also been observed. When the phase is shifted π or the signal is reversed, it becomes a negative wave that cancels itself out. The transmittance of light waves through a double-slit device should not be so weak. As a fundamental physical property, waves must have bandwidth, but light and quantum only have a single frequency, which does not conform to the Fourier transform principle that waves must follow. Light waves in optical fiber communication must produce modulation effect, which has not been shown in reality. If the light waves from different slits interfere with each other, a mask similar to a two-slit device will not allow the lithographer to work properly. A photon whose size is much smaller than the wave length does not represent the whole wave but only represents a sample of the wave, but the corresponding physical properties are not shown. A pair of stars orbiting each other without changing color only proves that redshift is impossible but not that the speed of light is constant. Due to the late birth of radio technology, many physical properties of electromagnetic waves were not included in the light and matter waves proposed earlier. The results of the double slit test only prove that the simple quantum particle model is incorrect but do not provide evidence that the wave model is correct.
Abstract The double slit test, as it is known, results in a series of alternating streaks of light and dark, presumed to be caused by interfering light waves. Careful comparison of experimental results and mathematical models reveals that the plausible theory of light-wave interference contains many fatal flaws. For example, the mathematical model does not have a mechanism for regularly producing multiple dark streaks. In practice, the spot where the dark streaks should appear is the brightest spot. Since only the electron radiates photons outward as it lowers its energy and returns to its ground state, the photon waves generated in the slit (possibly a vacuum) are of unknown origin. When light waves interfere with each other, photons can be infinitely subdivided and multiplied; After the head of the photon reaches the screen, the rest of the photon can still participate in interference; The effects of reflected light waves that most satisfy the interference conditions are not shown in the fringe. The important influence of polarization direction is not considered in the interference condition. In the causality test, the photon that has collapsed into a particle should be retested with a double slit test. In the causality test, the photon that has collapsed into a particle should be retested with a double slit test. The phenomenon of "observation determines outcome" has also been observed. When the phase is shifted π or the signal is reversed, it becomes a negative wave that cancels itself out. The transmittance of light waves through a double-slit device should not be so weak. As a fundamental physical property, waves must have bandwidth, but light and quantum only have a single frequency, which does not conform to the Fourier transform principle that waves must follow. Light waves in optical fiber communication must produce modulation effect, which has not been shown in reality. If the light waves from different slits interfere with each other, a mask similar to a two-slit device will not allow the lithographer to work properly. A photon whose size is much smaller than the wave length does not represent the whole wave but only represents a sample of the wave, but the corresponding physical properties are not shown. A pair of stars orbiting each other without changing color only proves that redshift is impossible but not that the speed of light is constant. Due to the late birth of radio technology, many physical properties of electromagnetic waves were not included in the light and matter waves proposed earlier. The results of the double slit test only prove that the simple quantum particle model is incorrect but do not provide evidence that the wave model is correct.
The double slit experiment was first conceived of by the English physician-physicist Thomas Young in 1801. It was the first demonstrative proof that light possesses a wave nature. In this experiment, light is made to pass through two very narrow slits that are spaced closely apart and a screen placed on the other side captures a pattern of alternating bright and dark stripes called fringes, formed as a result of the interference of ripples of light emanating from either slit. The relative positions and intensities of the fringes on the screen can be calculated by employing two assumptions that help simplify the geometry of the slit-screen arrangement. Firstly, the screen to slit distance is taken to be larger than the inter-slit distance (far field limit) and secondly, the inter-slit distance is taken to be larger than the wavelength of light. This conventional approach can account for the positions and intensities of the fringes located in the central portion of the screen with a fair degree of precision. It however, fails to account for those fringes located in the peripheral portions of the screen and also, is not applicable to the case wherein the screen to slit distance is made comparable to the inter-slit distance (near field limit). In this paper, the original analysis of Young’s Experiment is reformulated using an analytically derived hyperbola equation, which is formed from the locus of the points of intersections of two uniformly expanding circular wavefronts of light that emanate from either slit source. Additionally, the shape of the screen used to capture the interference pattern is varied (linear, semicircular, semielliptical) and the relative positions of the fringes is calculated for each case. This new approach bears the distinctive advantage that it is applicable in both the far field and the near field scenarios, and since no assumptions are made beyond the Huygens-Fresnel principle, it is therefore, a much more generalized approach. For these reasons, the author suggests that the new analysis ought to be introduced into the Wave Optics chapter of the undergraduate Physics curriculum.
Young’s double-slit experiment was first demonstrated with light and was later extended to electrons and other particles. These experiments share a common geometry: something approaches the slits, passes through them, and produces an interference pattern afterward. However, monochromatic water waves, electrons, and photons are physically different, and their interactions with a real slit need not be the same. Most discussions of the double-slit experiment focus on the interference pattern collected on a screen after the slits. Some descriptions also consider what happens before the slits, including the role of an eraser or observer and the splitting of an electron or photon to interfere with itself. Much less attention is given to what happens while an electron or photon is passing through a real slit. A real slit has thickness and is made of matter. Its surfaces contain atoms, electrons, and nuclei and therefore provide an electromagnetic environment through which an electron or photon passes. An electron or photon enters the slit, travels between its surfaces, and leaves it. This raises a missing question: can an electron or photon interact with this electromagnetic environment while passing through the slit, and can such an interaction affect its motion, particularly its exiting direction? We examine experimental evidence together with geometrical and accumulated-count evidence, including the observed spacing of interference maxima, the nonlinear geometry of constant-path-difference loci, the finite number and different possible counts of interference fringes, and the accumulation of individual detection events. Figures derived from the corresponding experimental and geometrical constructions are used to make these distinctions explicit. These results motivate a global description of Young’s double-slit experiment in three physically connected regions: pre-slit, in-slit, and post-slit. We call this the global trilogy of Young’s double-slit experiment. The global trilogy places the physical slit and its electromagnetic environment explicitly between the familiar pre-slit and post-slit descriptions and provides a framework for investigating the complete process from source, through the slit, to interference and detection.