杨氏双缝干涉实验与飞机安全着陆系统

杨氏双缝干涉实验是第一个证实光的波动性的著名实验,利用它可测量光的波长,在波动光学的发展中起着重要的作用.在通信领域中,杨氏双缝干涉实验原理构成了飞机安全着陆导航系统的理论基础之一,尤其是能见度不高的天气情况下,尽管实际的安全着陆系统比本文描述的复杂得多,但它们基于相同的原理.本文通过对美国大学物理教材中一道波动光学习题的赏析,简述杨氏双缝干涉实验原理在飞机安全着陆系统中的应用.     

利用GeoGebra软件绘制杨氏双缝干涉实验光强的动态分布

根据杨氏双缝干涉的实验原理,利用GeoGebra软件动态模拟出双缝干涉实验中光屏上的光强分布,课件中滑动条调节实验中的一个或几个参数均可得到直观反馈,同时在双缝与光屏间绘制出两个光源的波阵面,生动表现了因波阵面叠加产生相长干涉或相消干涉的原理.     

MATLAB GUI在光学实验教学中的应用

利用MATLAB GUI设计了杨氏双缝干涉、牛顿环干涉等经典光学实验的仿真平台。借助实验仿真平台,有助于加深对相关实验理论的理解;与实际的实验操作相结合,不仅可以激发学生的学习兴趣,也提高了课堂教学效果。     

单原子的双缝干涉实验

正著名的杨氏双缝实验演示了光的干涉原理。现在,利用激光激发单个铷原子,可以做一种等效的单原子的双缝干涉实验。在过去的20年里,我面试过400多名想来曼彻斯特大学学习物理的学生。杨氏双缝实验是经常出现的题目,显然让学生们感兴趣。但是,当我问起这个实验是什么,他们总是回答:用电子演示波粒二象性——量子物理学的基石之一。这很奇怪,因为杨(Thomas Young)在1804年做的这个实验——远在我们对电子或亚原子世界有任何了解之前。     

杨氏双缝干涉图样的理论模拟

本文在未经任何理论近似的情况下, 模拟了杨氏双缝干涉实验中观察屏上的干涉图样, 模拟结果不但 有利于学生全面掌握干涉条纹的分布规律, 而且有助于学生体会实验条件的重要性     

正交双缝干涉与衍射图象及其规律

正交双缝干涉与衍射图象及其规律列光华（广东湛江师院物理系５２４０４８）１．引言著名的杨氏双缝干涉实验首次使波动光学建立在实验基础上．本文研究了正交双缝的干涉与衍射综合效应图象及其规律．２．正交双缝夫琅和费衍射规律如图１所示，设正交双缝衍射屏具有二维的...     

杨氏双缝干涉实验中的光谱奇异现象

基于部分相干光的传输理论,研究了杨氏双缝干涉实验中的光谱奇异现象。发现在杨氏双缝干涉实验干涉场区中的某个点的光谱奇异现象,它会随着某些参量(如源光谱宽度Γ′,缝宽参量ε,相对空间相干度Δ0)的变化而改变,指出该现象可应用于信息的编码及自由空间的信息传输。     

万变不离其宗——看两道高考题所折射出的新课程理念

杨氏双缝干涉实验是高考物理的重要考查实验之一,在每年全国各省市的试题中均有体现．但是绝大多数学生在学习该知识时只是机械地记住相邻两条亮纹（或暗纹）间的距离公式,而对产生干涉现象的原理和条件不甚了解．2008年四川卷中的“双棱镜干涉”和2005年江苏卷中的“洛埃镜实验”正是以“杨氏双缝干涉实验”为依据,     

微波分光仪上双缝干涉实验中参数的选取

双缝干涉和双缝衍射其本质都是相干波的迭加,干涉和衍射没有严格的固定分界线。实验中为充分体现双缝干涉特征及规律,应恰当地选择和设定实验参数,并对双缝干涉的实验结果与杨氏双缝干涉及双缝衍射的结果进行对比讨论     

杨氏双缝干涉实验的可视化解释

杨氏双缝干涉实验是光具有波动性的有力证明, 为一探究竟, 本文用E x c e l的数和形的结合方法, 成功 看到了杨氏双缝干涉图样的内在面貌, 特别的方法, 使得本来不易研究的物理问题变得简单、 形象、 直观, 让我们从 另一个侧面看到了光波干涉现象和最本质的东西     

New gravitational experiment with ultracold neutrons

The results of a new neutron gravitation experiment are reported. The change in the energy of a neutron falling to a known height in the Earth’s gravitational field is compensated by an energy quantum ?Θ transferred to the neutron as a result of the phase modulation of the neutron wave. A phase diffraction grating moving across the direction of the propagation of the neutron wave is used as a modulator. The experiment has been carried out with ultracold neutrons Interference filters, neutron analogues of Fabry-Perot interferometers, are used for the spectrometry of ultracold neutrons. The force m _g g _n acting on the neutron in the Earth’s gravitational field has been measured with an accuracy of about 0.2%.     

Challenges to Bohr’s Wave-Particle Complementarity Principle

Contrary to Bohr’s complementarity principle, in 1995 Rabinowitz proposed that by using entangled particles from the source it would be possible to determine which slit a particle goes through while still preserving the interference pattern in the Young’s two slit experiment. In 2000, Kim et al. used spontaneous parametric down conversion to prepare entangled photons as their source, and almost achieved this. In 2012, Menzel et al. experimentally succeeded in doing this. When the source emits entangled particle pairs, the traversed slit is inferred from measurement of the entangled particle’s location by using triangulation. The violation of complementarity breaches the prevailing probabilistic interpretation of quantum mechanics, and benefits Bohm’s pilot-wave theory.     

Energy and fine structure of the lithium isoelectronic sequence

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Causal stochastic interpretation of quantum statistics

The differences between Einstein and Bohr on the interpretation of quantum mechanics revolved around the question of completeness of the Copenhagen Interpretation. This fundamental problem is examined here in the light of recent neutron interference experiments which allow for novel experimental situations. Exploiting the possibility of neutron spin flip in these experiments, the inadequacy of the Copenhagen interpretation to fully understand the experimental results is brought out. Instead a causal interpretation of quantum mechanics is advocated, in which the neutron, as a particle, does always have a definite space time trajectory but also involves a wave which creates a potential affecting the particle neutron. The reestablishment of definite particle trajectories in the microscopic domain obliges us to reexamine the statistical treatment of ‘identical’ particles, as well as the problem of negative energies and probabilities in relativistic quantum mechanics.     

On foundation of quantum physics

Some aspects of the interpretation of quantum theory are discussed. It is emphasized that quantum theory is formulated in the Cartesian coordinate system; in other coordinates the result obtained with the help of the Hamiltonian formalism and commutator relations between “canonically conjugated” coordinate and momentum operators leads to a wrong version of quantum mechanics. The origin of time is analyzed by the example of atomic collision theory in detail; it is shown that the time-dependent Schrödinger equation is meaningless since in the high-impact-energy limit it transforms into an equation with two time-like variables. Following the Einstein-Rozen-Podolsky experiment and Bell’s inequality, the wave function is interpreted as an actual field of information in the elementary form. The concept “measurement” is also discussed.     

Quantum Entanglement in Concept Combinations

Research in the application of quantum structures to cognitive science confirms that these structures quite systematically appear in the dynamics of concepts and their combinations and quantum-based models faithfully represent experimental data of situations where classical approaches are problematical. In this paper, we analyze the data we collected in an experiment on a specific conceptual combination, showing that Bell’s inequalities are violated in the experiment. We present a new refined entanglement scheme to model these data within standard quantum theory rules, where ‘entangled measurements and entangled evolutions’ occur, in addition to the expected ‘entangled states’, and present a full quantum representation in complex Hilbert space of the data. This stronger form of entanglement in measurements and evolutions might have relevant applications in the foundations of quantum theory, as well as in the interpretation of nonlocality tests. It could indeed explain some non-negligible ‘anomalies’ identified in EPR-Bell experiments.     

Experimental observations of redistributed energy in wave interference

Attempts to explain the redistribution of energy in interference has been done from time to time, under two of the most accepted theories, wave and quantum; however its mechanism still lacks clear interpretation. In this study, a new experiment has been designed and conducted to observe the redistributed energy in wave interference. Experimental observations on the redistributed energy that occurs in two interfering coherent waves are presented. Re-distributed energy at a certain region, (single bright fringe) in space due to interference of two waves was isolated at a plane and measured at a distant plane away from the isolated plane. The measured energy distribution of the isolated interference pattern was compared with the resultant calculated from the two individual interfering components based on wave theory. The calculated resultant due to the two individual components does not tally with the experimental observed pattern. Hence, the outcome of this experiment is in disagreement with the expected predictions as per the wave theory.     

The locality problem in quantum measurements

The locality problem of quantum measurements is considered in the framework of the algebraic approach. It is shown that contrary to the currently widespread opinion one can reconcile the mathematical formalism of the quantum theory with the assumption of the existence of a local physical reality determining the results of local measurements. The key quantum experiments: double-slit experiment on electron scattering, Wheeler’s delayed-choice experiment, the Einstein-Podolsky-Rosen paradox, and quantum teleportation are discussed from the locality-problem point of view. A clear physical interpretation for these experiments, which does not contradict the classical ideas, is given.     

A local-ether wave equation and speed-dependent mass and quantum energy

The east-west directional anisotropy in clock rate observed in the Hafele-Keating experiment with circumnavigation atomic clocks is commonly ascribed to the special relativity. In this investigation, based on the local-ether wave equation, an entirely different interpretation of this anisotropy is presented by showing that the clock-rate variation can originate from an intrinsic quantum property of the atom. For a harmonic-like wavefunction, the local-ether wave equation leads to a first-order time evolution equation similar to Schr?dinger's equation. However, the time derivative incorporates a speed-dependent factor similar to that in the Lorentz mass-variation law. Consequently, the quantum energy, the transition frequency, and hence the atomic clock rate decrease with the atom speed by this speed-dependent mass-variation factor. According to the local-ether model, the speed is referred specifically to a geocentric or heliocentric inertial frame for an earthbound or interplanetary clock, respectively. It is shown that this restriction on reference frame is actually in accord with the various experimental results of the anisotropy and the clock-rate difference in the Hafele-Keating experiment, the synchronism and the clock-rate adjustment in GPS (global positioning system), and of the spatial isotropy in the Hughes-Drever experiment. Moreover, the switching of the unique reference frame is in accord with the frequency-shift formulas adopted in earthbound and interplanetary spacecraft microwave links. Meanwhile, the local-ether model predicts a constant deviation in frequency shift from the calculated result reported in an interplanetary spacecraft link. This discrepancy then provides a means to test the local-ether wave equation. Received 11 December 2000 and Received in final form 20 August 2001     

Copenhagen quantum mechanics

In our quantum mechanics courses, measurement is usually taught in passing, as an ad-hoc procedure involving the ugly collapse of the wave function. No wonder we search for more satisfying alternatives to the Copenhagen interpretation. But this overlooks the fact that the approach fits very well with modern measurement theory with its notions of the conditioned state and quantum trajectory. In addition, what we know of as the Copenhagen interpretation is a later 1950s development and some of the earlier pioneers like Bohr did not talk of wave function collapse. In fact, if one takes these earlier ideas and mixes them with later insights of decoherence, a much more satisfying version of Copenhagen quantum mechanics emerges, one for which the collapse of the wave function is seen to be a harmless book keeping device. Along the way, we explain why chaotic systems lead to wave functions that spread out quickly on macroscopic scales implying that Schrödinger cat states are the norm rather than curiosities generated in physicists’ laboratories. We then describe how the conditioned state of a quantum system depends crucially on how the system is monitored illustrating this with the example of a decaying atom monitored with a time of arrival photon detector, leading to Bohr’s quantum jumps. On the other hand, other kinds of detection lead to much smoother behaviour, providing yet another example of complementarity. Finally we explain how classical behaviour emerges, including classical mechanics but also thermodynamics.