Young’s double slit experiments, which represent the mystery of quantum mechanics, have been described by the optic wave theory, the electromagnetic wave (EM wave) theory and pilot wave theory. Recently, the coexistence of the particle nature and the wave distribution of light in double slit experiments has been demonstrated. In this article we utilize the photon chamber to detect the traces of the light beam in the double slit experiments. The existence of the light tracks indicates the particle nature of the light beam in the wave experiments. The particle nature of the light beam is visualized by the tracks, while the wave-like distribution is visualized by the interference pattern. Furthermore, we cover the two sides of the chamber by copper foil for shielding the EM wave. If the light beams were the EM waves, then the interference pattern would be disturbed. The experiments show that the light behave as particles moving through the photon chamber, while distribute as waves without being disturbed. Thus, the double slit/photon chamber experiments visually indicate that the wave interpretations of the optical wave theory and the EM wave theory of the double slit experiments are incomplete. However, the experiments support the pilot wave theory at far field. The experiments in this article confirm the conclusions of the previous modified double slit experiments. But, the experimental devices, experimental setups and experimental observations are totally different. The experiments in this article make the mystery of the double slit experiments even more mysterious. The photon chamber is inexpensive and may be used to study the nature of the light.

Young’s double slit experiments have been interpretated by the optical wave theory. The observation of the wave behavior of the light near the detecting screen has long history. Recently we have shown the particle nature of the light near the detecting screen (the far field) in the wave experiments. In this article, we place two shields near the double slit to explore the nature of light. The experiment shows that, near the double slit, the light behaves as photons, propagates along the straight-line trajectories. The portion of the light, which directly passing through the channel formed by Shield-1 and Shield-2, produces the interference pattern at the central portion of the pattern. While the portions of the light, which are reflected multi-times by Shield-1 and Shield-2 respectively, produce the left pattern and the right pattern at the left-side and the right-side of the interference pattern respectively. The left pattern and the right pattern are not interference pattern. This novel double slit experiments provide comprehensive phenomena for further developing the theory to interpret the experiments.

The standard interpretation of Young’s double slit experiment is that the light behaves as waves before and after passing through the diaphragm of the double slit. There is one primary maximum intensity at the central position of the interference pattern. Recently, the photon chamber has been proposed and utilized to study the behavior of photons near the detecting screen. The experiments show that the light, near the screen, behaves as photons propagating along the straight-line trajectories that distribute as waves. In this article, we place the photon chamber near the diaphragm of the double slit. The Experiments show, the first time, that (1) within certain distance from the diaphragm, there is the non-wave pattern (two photon tracks), which indicates that the standard double slit experiments violate the wave interpretations; (2) the light beams behave as photons near the double slit.

To study the orientation-dependence of the diffraction patterns of the reflective grating, we utilize the cylindrical screen. Experiments show the curved, expanded and inclined diffraction patterns. The textbook-screen in the grating experiments is a planar screen and the diffraction orders distribute linearly in one dimension. The cylindrical screen visually shows that the diffraction orders of a rotating reflective grating distribute in two dimensions. The CCD can be placed at the accurate locations of each order to collect data. By using the cylindrical screen, only two coordinates are needed to describe the curved/expanded/inclined diffraction patterns of the rotating reflective grating. The cylindrical screen may be used to test the theories of the grating rotating around 3 axes.

Special Relativity (SR) is the cornerstone for modern physics and variety of applications. SR is based on two postulates, the principle of relativity (the first postulate) and the principle of constancy of speed of light (the second postulate). Recently we have (1) shown that the light propagate as particles/photons in the “pure” wave experiments, such as double slit and grating experiments; (2) proposed experiments to measure the speed of the photons by an observer moving relative to the source and thus, to test the second postulate for photons. In this article we propose a classroom experiment to test the second postulate. If the experiments show the existence of interference pattern (the negative result), the constancy of the speed of the photons holds, namely the second postulate of SR is experimentally confirmed. If the experiments show no interference pattern (positive result), then the propagation speed of photons is not constant, namely, the second postulate of SR is disproved. Either negative result or positive results would be profoundly significant.

In this article we propose a Photon chamber to detect the traces of the light beam in the grating experiments, namely to visualize the passage of light beam. The experiments show that the light beam behaves as particles moving through the Photon chamber, while still distributes as waves. The Photon chamber is inexpensive and discloses novel phenomena.

The common gratings contain transmission gratings and reflective gratings. Recently it has been shown that a transmission grating produces not only a transmission diffraction pattern but also a reflective diffraction pattern (dual pattern) simultaneously in the same experiment. Namely the transmission grating behaves not only as a transmission grating but also as a reflective grating simultaneously (dual-grating) in the same experiment. To study the orientation-dependence of the dual-patterns of the dual-grating experiments, in this article, we proposed the novel cylindrical screen.The cylindrical screen visually shows the location of each diffraction order in dual-grating experiments, such that the CCD/telescope can be placed at the accurate location to collect data. One of the benefits is that, by using the planar screen, three coordinates are needed to describe either the dual-pattern or the curved/expanded/inclined patterns, while by using the cylindrical screen, only two coordinates are needed to describe either the dual-pattern or the curved/expanded/inclined patterns.

The common gratings contain transmission gratings and reflective gratings. The orientation-dependence of the diffraction patterns of the transmission grating experiments have been systematically studied by rotating the grating around three axes. In this article, we show the novel phenomena that the transmission grating plays dual-roles of a transmission grating and a reflective grating.Indeed, the transmission grating produces simultaneously the transmission diffraction patterns and the reflective diffraction patterns respectively. This rather ancient grating experiment continues to surprise.

The orientation-dependence of the diffraction patterns of the 1D-grating experiments have been systematically studied by utilizing the 3-axis-rotation apparatus. It is shown that the spacings between adjacent diffraction orders are non-uniform. Namely, from “one end” of the pattern to “other end”, the spacings between adjacent diffraction orders gradually increase. In this article, we systematically study the orientation-dependence of the diffraction patterns of the 2D-cross-grating. The experiments show that the diffraction patterns are non-uniform as that of the 1D-grating experiments. This extraordinary phenomenon challenges the existing theoretical description of the grating experiments. The above observed phenomena provide the comprehensive phenomena to theoretical study of the grating experiments. We suggest that the complete mathematical model should contain three rotation angles as parameters and should be able to describe the phenomena of the non-uniform-spacing, curved, expanded, inclined and mirror-symmetric diffraction patterns consistently.

The phenomena of the rotating grating have been studied and have the varieties application. The diffraction normal order that is at the intersection of the grating’s normal vector and the screen is introduced and is the function of the incident angle of light, the grating spacing and wavelength. We suggest the following: (1) the diffraction normal order and the zeroth order () divide a diffraction pattern into three portions; each portion corresponds to a range of diffraction orders, , , , and is described by specific equation, respectively; (2) the number of the diffraction orders “m” in each portion is determined by the incident angle of light, the grating spacing, and wavelength; (3) the diffraction angles and positions of the diffraction orders of each portion can be presented in terms of and ; (4) the diffraction pattern of a rotating grating is non-uniform.

A Universal Mathematical Field Theory (UMFT) is established, which states that the combination of the operations of both gradient and divergence of vector fields, such as electric field and velocity field, create the curl of an axial vector field, such as magnetic field. Utilizing UMFT, we mathematically: (1) derive the Extended-Maxwell equations and the Lorentz force from Coulomb’s law and the velocity of the source; (2) establish Maxwell-type gravitational equations and Lorentz-type gravitational force (Gravito-EM) from Newton’s law and velocity of gravitational source; (3) establish Classical-Spin-Electromagnetism (Spin-EM) from the Coulomb’s law and the spin of the spin angular velocity; (4) predicate the Spin related force. For a source moving with non-spatially-varying velocity the Extended-Maxwell equations reduce to Maxwell equations, which justifies UMFT and shows that the experiments-based Maxwell equations have mathematical origin. This derivation mathematically explains how a moving electric charge creates magnetic field, and shows that there is no magnetic monopole charge. UMFT shows that mathematical identities lead to physical dualities including duality between EM and Gravito-EM. The concepts, effects and phenomena of EM may be directly converted to that of gravity. The Gravito-EM are employed to study the accelerating universe, rotation curve and gravitation waves. The Gravito-EM can be quantized, along the line of quantizing EM, and unified with EM force. We derive, for the first time, the Spin-Lorentz-type force and Lagrangian-Lorentz-type force. If experimentally proved, the Spin-related force may be the 5th force. UMFT provides mathematical origins of physical dualities between Extended EM, Gravito-EM and Spin-EM.

Young’s double slit experiments, which represent the mystery of quantum mechanics (Feynman), have been described by optics, electromagnetic wave theory, quantum wave theory and Bohm’s trajectory theory. The double slit has the varieties of the applications. To test the description theories, we perform the comprehensive double slit experiments, which show that (1) before passing through the double slit/cross-double slit and before landing on the screen, the laser light behaves as particles, not as waves; (2) the experiments challenge the computer simulation of the trajectory theory at near field, however support the trajectory theory at far field. Those novel phenomena provide the comprehensive information for further theoretical development and applications.