text:
1.1Classical particle and wave theories of light
1.2Black-body radiation and Planck's law
1.3Photoelectric effect
1.3.1Einstein's explanation of photoelectric effect
1.4de Broglie's hypothesis
1.5Heisenberg's uncertainty principle
1.6de Broglie–Bohm theory
2Wave nature of large objects
3Importance
4Visualization
5Alternative views
5.1Both-particle-and-wave view
5.2Wave-only view
5.3Particle-only view
5.4Neither-wave-nor-particle view
6Uses
Wave–particle duality
(Redirected from Wave particle duality)
Concept in quantum mechanics
Part of a series of articles about
i ℏ ∂ ∂ t | ψ ( t ) ⟩ = H ^ | ψ ( t ) ⟩ {\displaystyle i\hbar {\frac {\partial }{\partial t}}|\psi (t)\rangle ={\hat {H}}|\psi (t)\rangle }
Schrödinger equation
Old quantum theory
Bra–ket notation
Energy level
Nonlocality
Quantum number
Tunnelling
Wave function
Bell's inequality
Davisson–Germer
Double-slit
Elitzur–Vaidman
Franck–Hertz
Leggett–Garg inequality
Mach–Zehnder
Delayed-choice
Schrödinger's cat
Stern–Gerlach
Wheeler's delayed-choice
Phase-space
Sum-over-histories (path integral)
Klein–Gordon
Bayesian
Consistent histories
de Broglie–Bohm
Hidden-variable
Many-worlds
Objective collapse
Relativistic quantum mechanics
Quantum chaos
EPR paradox
Density matrix
Scattering theory
Quantum statistical mechanics
Quantum machine learning
Aharonov
Blackett
Davisson
Ehrenfest
Fock
Kramers
Laue
Millikan
Onnes
Planck
von Neumann
Wigner
Zeeman
Wave–particle duality is the concept in quantum mechanics that every particle or quantum entity may be described as either a particle or a wave. It expresses the inability of the classical concepts "particle" or "wave" to fully describe the behaviour of quantum-scale objects. As Albert Einstein wrote:[1]
It seems as though we must use sometimes the one theory and sometimes the other, while at times we may use either. We are faced with a new kind of difficulty. We have two contradictory pictures of reality; separately neither of them fully explains the phenomena of light, but together they do.
Through the work of Max Planck, Albert Einstein, Louis de Broglie, Arthur Compton, Niels Bohr, Erwin Schrödinger and many others, current scientific theory holds that all particles exhibit a wave nature and vice versa.[2] This phenomenon has been verified not only for elementary particles, but also for compound particles like atoms and even molecules. For macroscopic particles, because of their extremely short wavelengths, wave properties usually cannot be detected.[3]
Although the use of the wave–particle duality has worked well in physics, the meaning or interpretation has not been satisfactorily resolved; see interpretations of quantum mechanics.
Bohr regarded the "duality paradox" as a fundamental or metaphysical fact of nature. A given kind of quantum object will exhibit sometimes wave, sometimes particle, character, in respectively different physical settings. He saw such duality as one aspect of the concept of complementarity.[4] Bohr regarded renunciation of the cause-effect relation, or complementarity, of the space-time picture, as essential to the quantum mechanical account.[5]
Werner Heisenberg considered the question further. He saw the duality as present for all quantic entities, but not quite in the usual quantum mechanical account considered by Bohr. He saw it in what is called second quantization, which generates an entirely new concept of fields that exist in ordinary space-time, causality still being visualizable. Classical field values (e.g. the electric and magnetic field strengths of Maxwell) are replaced by an entirely new kind of field value, as considered in quantum field theory. Turning the reasoning around, ordinary quantum mechanics can be deduced as a specialized consequence of quantum field theory.[6][7]
Classical particle and wave theories of light[edit]
Thomas Young's sketch of two-slit diffraction of waves, 1803.
Democritus (5th century BC) argued that all things in the universe, including light, are composed of indivisible sub-components.[8] Euclid (4th–3rd century BC) gives treatises on light propagation, states the principle of shortest trajectory of light, including multiple reflections on mirrors, including spherical, while Plutarch (1st–2nd century AD) describes multiple reflections on spherical mirrors discussing the creation of larger or smaller images, real or imaginary, including the case of chirality of the images. At the beginning of the 11th century, the Arabic scientist Ibn al-Haytham wrote the first comprehensive Book of Optics describing reflection, refraction, and the operation of a pinhole lens via rays of light traveling from the point of emission to the eye. He asserted that these rays were composed of particles of light. In 1630, René Descartes popularized the opposing wave description in his treatise on light, The World, showing that the behaviour of light could be re-created by modeling wave-like disturbances in a universal medium i.e. luminiferous aether. Beginning in 1670 and progressing over three decades, Isaac Newton developed and championed his corpuscular theory, arguing that the perfectly straight lines of reflection demonstrated light's particle nature, only particles could travel in such straight lines. He explained refraction by positing that particles of light accelerated laterally upon entering a denser medium. Around the same time, Newton's contemporaries Robert Hooke and Christiaan Huygens, and later Augustin-Jean Fresnel, mathematically refined the wave viewpoint, showing that if light traveled at different speeds in different media, refraction could be easily explained as the medium-dependent propagation of light waves. The resulting Huygens–Fresnel principle was extremely successful at reproducing light's behaviour and was subsequently supported by Thomas Young's discovery of wave interference of light by his double-slit experiment in 1801.[9] The wave view did not immediately displace the ray and particle view, but began to dominate scientific thinking about light in the mid 19th century, since it could explain polarization phenomena that the alternatives could not.[10]
James Clerk Maxwell discovered that he could apply his previously discovered Maxwell's equations, along with a slight modification to describe self-propagating waves of oscillating electric and magnetic fields. It quickly became apparent that visible light, ultraviolet light, and infrared light were all electromagnetic waves of differing frequency.
Animation showing the wave–particle duality with a double-slit experiment and effect of an observer. Increase size to see explanations in the video itself. See also a quiz based on this animation.
Particle impacts make visible the interference pattern of waves.
A quantum particle is represented by a wave packet.
Interference of a quantum particle with itself.
Black-body radiation and Planck's law[edit]
Main article: Black-body radiation
In 1901, Max Planck published an analysis that succeeded in reproducing the observed spectrum of light emitted by a glowing object. To accomplish this, Planck had to make a mathematical assumption of quantized energy of the oscillators, i.e. atoms of the black body that emit radiation. Einstein later proposed that electromagnetic radiation itself is quantized, not the energy of radiating atoms.
Black-body radiation, the emission of electromagnetic energy due to an object's heat, could not be explained from classical arguments alone. The equipartition theorem of classical mechanics, the basis of all classical thermodynamic theories, stated that an object's energy is partitioned equally among the object's vibrational modes. But applying the same reasoning to the electromagnetic emission of such a thermal object was not so successful. That thermal objects emit light had been long known. Since light was known to be waves of electromagnetism, physicists hoped to describe this emission via classical laws. This became known as the black body problem. Since the equipartition theorem worked so well in describing the vibrational modes of the thermal object itself, it was natural to assume that it would perform equally well in describing the radiative emission of such objects. But a problem quickly arose if each mode received an equal partition of energy, the short wavelength modes would consume all the energy. This became clear when plotting the Rayleigh–Jeans law, which, while correctly predicting the intensity of long wavelength emissions, predicted infinite total energy as the intensity diverges to infinity for short wavelengths. This became known as the ultraviolet catastrophe.
In 1900, Max Planck hypothesized that the frequency of light emitted by the black body depended on the frequency of the oscillator that emitted it, and the energy of these oscillators increased linearly with frequency (according E = hf where h is Planck's constant and f is the frequency). This was not an unsound proposal considering that macroscopic oscillators operate similarly when studying five simple harmonic oscillators of equal amplitude but different frequency, the oscillator with the highest frequency possesses the highest energy (though this relationship is not linear like Planck's). By demanding that high-frequency light must be emitted by an oscillator of equal frequency, and further requiring that this oscillator occupy higher energy than one of a lesser frequency, Planck avoided any catastrophe, giving an equal partition to high-frequency oscillators produced successively fewer oscillators and less emitted light. And as in the Maxwell–Boltzmann distribution, the low-frequency, low-energy oscillators were suppressed by the onslaught of thermal jiggling from higher energy oscillators, which necessarily increased their energy and frequency.
The most revolutionary aspect of Planck's treatment of the black body is that it inherently relies on an integer number of oscillators in thermal equilibrium with the electromagnetic field. These oscillators give their entire energy to the electromagnetic field, creating a quantum of light, as often as they are excited by the electromagnetic field, absorbing a quantum of light and beginning to oscillate at the corresponding frequency. Planck had intentionally created an atomic theory of the black body, but had unintentionally generated an atomic theory of light, where the black body never generates quanta of light at a given frequency with an energy less than hf. However, once realizing that he had quantized the electromagnetic field, he denounced particles of light as a limitation of his approximation, not a property of reality.
Photoelectric effect[edit]
Main article: Photoelectric effect
The photoelectric effect. Incoming photons on the left strike a metal plate (bottom), and eject electrons, depicted as flying off to the right.
While Planck had solved the ultraviolet catastrophe by using atoms and a quantized electromagnetic field, most contemporary physicists agreed that Planck's "light quanta" represented only flaws in his model. A more-complete derivation of black-body radiation would yield a fully continuous and "wave-like" electromagnetic field with no quantization. However, in 1905 Albert Einstein took Planck's black body model to produce his solution to another outstanding problem of the day: the photoelectric effect, wherein electrons are emitted from atoms when they absorb energy from light. Since their existence was theorized eight years previously, phenomena had been studied with the electron model in mind in physics laboratories worldwide.
In 1902, Philipp Lenard discovered that the energy of these ejected electrons did not depend on the intensity of the incoming light, but instead on its frequency. So if one shines a little low-frequency light upon a metal, a few low energy electrons are ejected. If one now shines a very intense beam of low-frequency light upon the same metal, a whole slew of electrons are ejected; however they possess the same low energy, there are merely more of them. The more light there is, the more electrons are ejected. Whereas in order to get high energy electrons, one must illuminate the metal with high-frequency light. Like blackbody radiation, this was at odds with a theory invoking continuous transfer of energy between radiation and matter. However, it can still be explained using a fully classical description of light, as long as matter is quantum mechanical in nature.[11]
If one used Planck's energy quanta, and demanded that electromagnetic radiation at a given frequency could only transfer energy to matter in integer multiples of an energy quantum hf, then the photoelectric effect could be explained very simply. Low-frequency light only ejects low-energy electrons because each electron is excited by the absorption of a single photon. Increasing the intensity of the low-frequency light (increasing the number of photons) only increases the number of excited electrons, not their energy, because the energy of each photon remains low. Only by increasing the frequency of the light, and thus increasing the energy of the photons, can one eject electrons with higher energy. Thus, using Planck's constant h to determine the energy of the photons based upon their frequency, the energy of ejected electrons should also increase linearly with frequency, the gradient of the line being Planck's constant. These results were not confirmed until 1915, when Robert Andrews Millikan produced experimental results in perfect accord with Einstein's predictions.
While energy of ejected electrons reflected Planck's constant, the existence of photons was not explicitly proven until the discovery of the photon antibunching effect. This refers to the observation that once a single emitter (an atom, molecule, solid state emitter, etc.) radiates a detectable light signal, it cannot immediately release a second signal until after the emitter has been re-excited. This leads to a statistically quantifiable time delay between light emissions, so detection of multiple signals becomes increasingly unlikely as the observation time dips under the excited-state lifetime of the emitter.[12] The effect can be demonstrated in an undergraduate-level lab.[13]
This phenomenon could only be explained via photons. Einstein's "light quanta" would not be called photons until 1925, but even in 1905 they represented the quintessential example of wave–particle duality. Electromagnetic radiation propagates following linear wave equations, but can only be emitted or absorbed as discrete elements, thus acting as a wave and a particle simultaneously.
Einstein's explanation of photoelectric effect[edit]
In 1905, Albert Einstein provided an explanation of the photoelectric effect, an experiment that the wave theory of light failed to explain. He did so by postulating the existence of photons, quanta of light energy with particulate qualities.
In the photoelectric effect, it was observed that shining a light on certain metals would lead to an electric current in a circuit. Presumably, the light was knocking electrons out of the metal, causing current to flow. However, using the case of potassium as an example, it was also observed that while a dim blue light was enough to cause a current, even the strongest, brightest red light available with the technology of the time caused no current at all. According to the classical theory of light and matter, the strength or amplitude of a light wave was in proportion to its brightness: a bright light should have been easily strong enough to create a large current. Yet, oddly, this was not so.
Einstein explained this enigma by postulating that electrons can receive energy from an electromagnetic field only in discrete units (quanta or photons): an amount of energy E that was related to the frequency f of the light by
E = h f {\displaystyle E=hf\,}
where h is Planck's constant (6.626 × 10−34 Js). Only photons of a high enough frequency (above a certain threshold value) could knock an electron free. For example, photons of blue light had sufficient energy to free an electron from the metal, but photons of red light did not. One photon of light above the threshold frequency could release only one electron; the higher the frequency of a photon, the higher the kinetic energy of the emitted electron, but no amount of light below the threshold frequency could release an electron. To violate this law would require extremely high-intensity lasers that had not yet been invented. Intensity-dependent phenomena have now been studied in detail with such lasers.[14]
Einstein was awarded the Nobel Prize in Physics in 1921 for his discovery of the law of the photoelectric effect.
de Broglie's hypothesis[edit]
Main article: Matter wave
Propagation of de Broglie waves in 1d—real part of the complex amplitude is blue, imaginary part is green. The probability (shown as the colour opacity) of finding the particle at a given point x is spread out like a waveform; there is no definite position of the particle. As the amplitude increases above zero the curvature decreases, so the amplitude decreases again, and vice versa—the result is an alternating amplitude: a wave. Top: Plane wave. Bottom: Wave packet.
In 1924, Louis-Victor de Broglie formulated the de Broglie hypothesis, claiming that all matter has a wave-like nature.[15][16] He related wavelength and momentum:
λ = h p {\displaystyle \lambda ={\frac {h}{p}}}
This is a generalization of Einstein's equation above, since the momentum of a photon is given by p = E c {\displaystyle p={\tfrac {E}{c}}} and the wavelength (in a vacuum) by λ = c f {\displaystyle \lambda ={\tfrac {c}{f}}} , where c is the speed of light in vacuum.
De Broglie's formula was confirmed three years later for electrons with the observation of electron diffraction, as it had been observed with X-rays, in two independent experiments. At the University of Aberdeen, George Paget Thomson passed a beam of electrons through a thin metal film and observed the predicted interference patterns. At Bell Labs, Clinton Joseph Davisson and Lester Halbert Germer guided the electron beam through a crystalline grid in their experiment popularly known as Davisson–Germer experiment.
De Broglie was awarded the Nobel Prize for Physics in 1929 for his hypothesis. Thomson and Davisson shared the Nobel Prize for Physics in 1937 for their experimental work.
De Broglie's proposal also predicts particle interferometry. In particular, single-particle interferometry has become a classic for its clarity in expressing the central puzzles of quantum mechanics. Because it demonstrates the fundamental limitation of the ability of the observer to predict experimental results, Richard Feynman called it "a phenomenon which is impossible […] to explain in any classical way, and which has in it the heart of quantum mechanics. In reality, it contains the only mystery [of quantum mechanics].[17] In 1974, the Italian physicists Pier Giorgio Merli, Gian Franco Missiroli, and Giulio Pozzi performed the first experiment of single particle interferometry using electrons and a biprism (instead of slits), showing that each electron interferes with itself as predicted by quantum theory.[18][19] In 2018, single particle interference has been first demonstrated for antimatter in the Positron Laboratory (L-NESS) of Rafael Ferragut in Como (Italy), by a group led by Marco Giammarchi.[20]
Heisenberg's uncertainty principle[edit]
Main article: Uncertainty principle
In his work on formulating quantum mechanics, Werner Heisenberg postulated his uncertainty principle, which states:
Δ x Δ p ≥ 1 2 ℏ {\displaystyle \Delta x\,\Delta p\geq {\tfrac {1}{2}}\hbar }
Δ {\displaystyle \Delta } here indicates standard deviation, a measure of spread or uncertainty;
x and p are a particle's position and linear momentum respectively.
ℏ {\displaystyle \hbar } is the reduced Planck's constant (Planck's constant divided by 2 π {\displaystyle \pi } ).
Heisenberg originally explained this as a consequence of the process of measuring: Measuring position accurately would disturb momentum and vice versa, offering an example (the "gamma-ray microscope") that depended crucially on the de Broglie hypothesis. The thought is now, however, that this only partly explains the phenomenon, but that the uncertainty also exists in the particle itself, even before the measurement is made.
In fact, the modern explanation of the uncertainty principle, extending the Copenhagen interpretation first put forward by Bohr and Heisenberg, depends even more centrally on the wave nature of a particle. Just as it is nonsensical to discuss the precise location of a wave on a string, particles do not have perfectly precise positions; likewise, just as it is nonsensical to discuss the wavelength of a "pulse" wave traveling down a string, particles do not have perfectly precise momenta that correspond to the inverse of wavelength. Moreover, when position is relatively well defined, the wave is pulse-like and has a very ill-defined wavelength, and thus momentum. And conversely, when momentum, and thus wavelength, is relatively well defined, the wave looks long and sinusoidal, and therefore it has a very ill-defined position.
de Broglie–Bohm theory[edit]
Main article: de Broglie–Bohm theory
Couder experiments,[21] "materializing" the pilot wave model
De Broglie himself had proposed a pilot wave construct to explain the observed wave–particle duality. In this view, each particle has a well-defined position and momentum, but is guided by a wave function derived from Schrödinger's equation. The pilot wave theory was initially rejected because it generated non-local effects when applied to systems involving more than one particle. Non-locality, however, soon became established as an integral feature of quantum theory and David Bohm extended de Broglie's model to explicitly include it.
In the resulting representation, also called the de Broglie–Bohm theory or Bohmian mechanics,[22] the wave–particle duality vanishes, and explains the wave behaviour as a scattering with wave appearance, because the particle's motion is subject to a guiding equation or quantum potential.
This idea seems to me so natural and simple, to resolve the wave–particle dilemma in such a clear and ordinary way, that it is a great mystery to me that it was so generally ignored.[23] – J.S.Bell
The best illustration of the pilot-wave model was given by Couder's 2010 "walking droplets" experiments,[24] demonstrating the pilot-wave behaviour in a macroscopic mechanical analog.[21]
Wave nature of large objects[edit]
Since the demonstrations of wave-like properties in photons and electrons, similar experiments have been conducted with neutrons and protons. Among the most famous experiments are those of Estermann and Otto Stern in 1929.[25] Authors of similar recent experiments with atoms and molecules, described below, claim that these larger particles also act like waves.
A dramatic series of experiments emphasizing the action of gravity in relation to wave–particle duality was conducted in the 1970s using the neutron interferometer.[26] Neutrons, one of the components of the atomic nucleus, provide much of the mass of a nucleus and thus of ordinary matter. In the neutron interferometer, they act as quantum-mechanical waves directly subject to the force of gravity. While the results were not surprising since gravity was known to act on everything, including light (see tests of general relativity and the Pound–Rebka falling photon experiment), the self-interference of the quantum mechanical wave of a massive fermion in a gravitational field had never been experimentally confirmed before.
In 1999, the diffraction of C60 fullerenes by researchers from the University of Vienna was reported.[27] Fullerenes are comparatively large and massive objects, having an atomic mass of about 720 u. The de Broglie wavelength of the incident beam was about 2.5 pm, whereas the diameter of the molecule is about 1 nm, about 400 times larger. In 2012, these far-field diffraction experiments could be extended to phthalocyanine molecules and their heavier derivatives, which are composed of 58 and 114 atoms respectively. In these experiments the build-up of such interference patterns could be recorded in real time and with single molecule sensitivity.[28]
In 2003, the Vienna group also demonstrated the wave nature of tetraphenylporphyrin[29]—a flat biodye with an extension of about 2 nm and a mass of 614 u. For this demonstration they employed a near-field Talbot Lau interferometer.[30][31] In the same interferometer they also found interference fringes for C60F48, a fluorinated buckyball with a mass of about 1600 u, composed of 108 atoms.[29] Large molecules are already so complex that they give experimental access to some aspects of the quantum-classical interface, i.e., to certain decoherence mechanisms.[32][33] In 2011, the interference of molecules as heavy as 6910 u could be demonstrated in a Kapitza–Dirac–Talbot–Lau interferometer.[34] In 2013, the interference of molecules beyond 10,000 u has been demonstrated.[35]
Whether objects heavier than the Planck mass (about the weight of a large bacterium) have a de Broglie wavelength is theoretically unclear and experimentally unreachable; above the Planck mass a particle's Compton wavelength would be smaller than the Planck length and its own Schwarzschild radius, a scale at which current theories of physics may break down or need to be replaced by more general ones.[36]
Couder, Fort, et al. showed[37] that macroscopic oil droplets on a vibrating fluid bath can be used as an analogue model of wave–particle duality; a localized droplet creates periodical wave field around itself. Resonant interaction between the droplet and its own wave field exhibits behaviour analogous to quantum particles: interference in double-slit experiment,[38] unpredictable tunneling[39] (depending in complicated way on practically hidden state of field), orbit quantization[40] (that particle has to 'find a resonance' with field perturbations it creates—after one orbit, its internal phase has to return to the initial state) and Zeeman effect.[41] Note that other single and double slit experiments [42][43] have shown that wall-droplet interactions rather than diffraction or interference of the pilot wave may be responsible for the observed hydrodynamic patterns, which are different from slit-induced interference patterns exhibited by quantum particles.
Importance[edit]
Wave–particle duality is deeply embedded into the foundations of quantum mechanics. In the formalism of the theory, all the information about a particle is encoded in its wave function, a complex-valued function roughly analogous to the amplitude of a wave at each point in space. This function evolves according to Schrödinger equation. For particles with mass this equation has solutions that follow the form of the wave equation. Propagation of such waves leads to wave-like phenomena such as interference and diffraction. Particles without mass, like photons, have no solutions of the Schrödinger equation. Instead of a particle wave function that localizes mass in space, a photon wave function can be constructed from Einstein kinematics to localize energy in spatial coordinates.[44]
The particle-like behaviour is most evident due to phenomena associated with measurement in quantum mechanics. Upon measuring the location of the particle, the particle will be forced into a more localized state as given by the uncertainty principle. When viewed through this formalism, the measurement of the wave function will randomly lead to wave function collapse to a sharply peaked function at some location. For particles with mass, the likelihood of detecting the particle at any particular location is equal to the squared amplitude of the wave function there. The measurement will return a well-defined position, and is subject to Heisenberg's uncertainty principle.
Following the development of quantum field theory the ambiguity disappeared. The field permits solutions that follow the wave equation, which are referred to as the wave functions. The term particle is used to label the irreducible representations of the Lorentz group that are permitted by the field. An interaction as in a Feynman diagram is accepted as a calculationally convenient approximation where the outgoing legs are known to be simplifications of the propagation and the internal lines are for some order in an expansion of the field interaction. Since the field is non-local and quantized, the phenomena that previously were thought of as paradoxes are explained. Within the limits of the wave–particle duality the quantum field theory gives the same results.
Visualization[edit]
There are two ways to visualize the wave-particle behaviour: by the standard model and by the de Broglie–Bohm theory.
Below is an illustration of wave–particle duality as it relates to de Broglie's hypothesis and Heisenberg's Uncertainty principle, in terms of the position and momentum space wavefunctions for one spinless particle with mass in one dimension. These wavefunctions are Fourier transforms of each other.
The more localized the position-space wavefunction, the more likely the particle is to be found with the position coordinates in that region, and correspondingly the momentum-space wavefunction is less localized so the possible momentum components the particle could have are more widespread.
Conversely, the more localized the momentum-space wavefunction, the more likely the particle is to be found with those values of momentum components in that region, and correspondingly the less localized the position-space wavefunction, so the position coordinates the particle could occupy are more widespread.
Position x and momentum p wavefunctions corresponding to quantum particles. The colour opacity of the particles corresponds to the probability density of finding the particle with position x or momentum component p.
Top: If wavelength λ is unknown, so are momentum p, wave-vector k and energy E (de Broglie relations). As the particle is more localized in position space, Δx is smaller than for Δpx.
Bottom: If λ is known, so are p, k, and E. As the particle is more localized in momentum space, Δp is smaller than for Δx.
Alternative views[edit]
Wave–particle duality is an ongoing conundrum in modern physics. Most physicists accept wave–particle duality as the best explanation for a broad range of observed phenomena; however, it is not without controversy. Alternative views are also presented here. These views are not generally accepted by mainstream physics, but serve as a basis for valuable discussion within the community.
Both-particle-and-wave view[edit]
The pilot wave model, was originally developed by Louis de Broglie and further developed by David Bohm into the hidden variable theory. The phrase "hidden variable" is misleading since the variable in question is the positions of the particles.[45] Instead of duality, the pilot wave model proposes that both wave and particle are present with the wave guiding the particle in a deterministic fashion. The wave in question is the wavefunction obeying Schrödinger's equation. Bohm's formulation is intended to be classical, but it has to incorporate a distinctly non-classical feature: a nonlocal force ("quantum potential") acting on the particles.
Bohm's original purpose (1952) "was to show that an alternative to the Copenhagen interpretation is at least logically possible.[46] Soon after he set the project aside and did not revive it until he met Basil Hiley in 1961 when both were at Birbeck College (University of London). Bohm and Hiley then wrote extensively on the theory and it gained a wider audience. This idea is held by a significant minority within the physics community.[47]
The Afshar experiment[48] (2007) may suggest that it is possible to simultaneously observe both wave and particle properties of photons. This claim is, however, disputed by other scientists.[49][50][51][52]
Wave-only view[edit]
Carver Mead, an American scientist and professor at Caltech, said that the duality can be replaced by a "wave-only" view. In his book Collective Electrodynamics: Quantum Foundations of Electromagnetism (2000), Mead purports to analyze the behaviour of electrons and photons purely in terms of electron wave functions, and attributes the apparent particle-like behaviour to quantization effects and eigenstates. According to reviewer David Haddon:[53]
Mead has cut the Gordian knot of quantum complementarity. He claims that atoms, with their neutrons, protons, and electrons, are not particles at all but pure waves of matter. Mead cites as the gross evidence of the exclusively wave nature of both light and matter the discovery between 1933 and 1996 of ten examples of pure wave phenomena, including the ubiquitous laser of CD players, the self-propagating electrical currents of superconductors, and the Bose–Einstein condensate of atoms.
Albert Einstein, who, in his search for a Unified Field Theory, did not accept wave–particle duality, wrote:[54]
This double nature of radiation (and of material corpuscles) ... has been interpreted by quantum-mechanics in an ingenious and amazingly successful fashion. This interpretation ... appears to me as only a temporary way out...
The many-worlds interpretation (MWI) is sometimes presented as a waves-only theory, including by its originator, Hugh Everett who referred to MWI as "the wave interpretation".[55]
The three wave hypothesis of R. Horodecki relates the particle to wave.[56][57] The hypothesis implies that a massive particle is an intrinsically spatially, as well as temporally extended, wave phenomenon by a nonlinear law.
The deterministic collapse theory[58] considers collapse and measurement as two independent physical processes. Collapse occurs when two wavepackets spatially overlap and satisfy a mathematical criterion, which depends on the parameters of both wavepackets. It is a contraction to the overlap volume. In a measurement apparatus one of the two wavepackets is one of the atomic clusters, which constitute the apparatus, and the wavepackets collapse to at most the volume of such a cluster. This mimics the action of a point particle.
Hegerfeldt's theorem, which appears to demonstrates the incompatibility of the existence of localized discrete particles with the combination of the principles of quantum mechanics and special relativity, has also been used to support the conclusion that reality must be described solely in terms of field-based formulations.[59]
Particle-only view[edit]
Still in the days of the old quantum theory, a pre-quantum-mechanical version of wave–particle duality was pioneered by William Duane,[60] and developed by others including Alfred Landé.[61] Duane explained diffraction of x-rays by a crystal in terms solely of their particle aspect. The deflection of the trajectory of each diffracted photon was explained as due to quantized momentum transfer from the spatially regular structure of the diffracting crystal.[62]
Neither-wave-nor-particle view[edit]
It has been argued that there are never exact particles or waves, but only some compromise or intermediate between them. For this reason, in 1928 Arthur Eddington[63] coined the name "wavicle" to describe the objects although it is not regularly used today. One consideration is that zero-dimensional mathematical points cannot be observed. Another is that the formal representation of such points, the Dirac delta function is unphysical, because it cannot be normalized. Parallel arguments apply to single-frequency wave states. Roger Penrose states:[64]
Such 'position states' are idealized wavefunctions in the opposite sense from the momentum states. Whereas the momentum states are infinitely spread out, the position states are infinitely concentrated. Neither is normalizable [...].
Uses[edit]
Although it is difficult to draw a line separating wave–particle duality from the rest of quantum mechanics, it is nevertheless possible to list some applications of this basic idea.
Wave–particle duality is exploited in electron microscopy, where the small wavelengths associated with the electron can be used to view objects much smaller than what is visible using visible light.
Similarly, neutron diffraction uses neutrons with a wavelength of about 0.1 nm, the typical spacing of atoms in a solid, to determine the structure of solids.
Photos are now able to show this dual nature, which may lead to new ways of examining and recording this behaviour.[65]
Afshar experiment
Arago spot
Basic concepts of quantum mechanics
Complementarity (physics)
Einstein's thought experiments
Englert–Greenberger–Yasin duality relation
Faraday wave
Hanbury Brown and Twiss effect
Kapitsa–Dirac effect
Photon polarization
Wheeler's delayed choice experiment
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^ Walter Greiner (2001). Quantum Mechanics: An Introduction. Springer. ISBN 978-3-540-67458-0.
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^ Peter Gabriel Bergmann, The Riddle of Gravitation, Courier Dover Publications, 1993 ISBN 0-486-27378-4 online
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^ Paul Arthur Schilpp, ed, Albert Einstein: Philosopher-Scientist, Open Court (1949), ISBN 0-87548-133-7, p. 51.
^ See section VI(e) of Everett's thesis: The Theory of the Universal Wave Function, in Bryce Seligman DeWitt, R. Neill Graham, eds, The Many-Worlds Interpretation of Quantum Mechanics, Princeton Series in Physics, Princeton University Press (1973), ISBN 0-691-08131-X, pp. 3–140.
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^ Landé, A. (1951). Quantum Mechanics, Sir Isaac Pitman and Sons, London, pp. 19–22.
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^ Eddington, Arthur Stanley (1928). The Nature of the Physical World. Cambridge, UK: MacMillan. pp. 201.
^ Penrose, Roger (2007). The Road to Reality: A Complete Guide to the Laws of the Universe. Vintage. p. 521, §21.10. ISBN 978-0-679-77631-4.
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Animation, applications and research linked to the wave–particle duality and other basic quantum phenomena (Université Paris Sud)
H. Nikolic (2007). "Quantum mechanics: Myths and facts". Foundations of Physics. 37 (11): 1563–1611. arXiv:quant-ph/0609163. Bibcode:2007FoPh...37.1563N. doi:10.1007/s10701-007-9176-y. S2CID 9613836.
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E.H. Carlson, Wave–Particle Duality: Light on Project PHYSNET
R. Nave. "Wave–Particle Duality" (Web page). HyperPhysics. Georgia State University, Department of Physics and Astronomy. Retrieved December 12, 2005.
Juffmann, Thomas; et al. (25 March 2012). "Real-time single-molecule imaging of quantum interference". Nature Nanotechnology. 7 (5): 297–300. arXiv:1402.1867. Bibcode:2012NatNa...7..297J. doi:10.1038/nnano.2012.34. PMID 22447163. S2CID 5918772. Archived from the original on 5 October 2016. Retrieved 21 January 2014.
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Ahead of the official reveal of some new Pokemon news due out tomorrow was a leak of seven new Pokemon from the upcoming Pokemon Sun and Moon titles due out in November and they're receiving mixed reviews. While Verge wasn't a fan, Kotaku was a little less harsh. You can take a look at the latest Japanese trailer below ahead of the official translated version that should arrive tomorrow morning!
Super Mario RPG is coming to the U.S.
If you remember this iconic box art then you've been playing video games for a long time and the re-release for the Super Mario RPG has been a long time coming. The original game, released for the Super Nintendo System back in 1996, is finally getting a re-release for the Wii U virtual console. (with off screen support included) After the release came to Europe last year, gamers have been patiently waiting for news about the title to hit stateside and now it's officially on the Nintendo website. The title mirrors classic RPG's from the 90s with a top down view and turn based combat, closer to early Final Fantasy titles. The title will release for the Wii U June 30th!
Bad news for Batman: Return to Arkham
More bad news for fans of the Batman game series as the latest title has been postponed indefinitely. According to WBgames, Virtuous games was not quite there in terms of quality for a rumored July release. The title would have featured remastered versions of both Batman: Arkham Asylum and Batman: Arkham City. While we don't know when the title will be released, Telltale Games Batman title will be arriving on consoles in a 5 episode format this fall.
More Pokemon Sun and Moon news is coming
More Pokemon Sun and Moon news is on its way. After a pretty lackluster reveal at the Nintendo Treehouse event during E3, even more info is coming our way. What we'll see this time around is really up in the air considering the look at the demo, new starters, and new legendary types but possibly more new Pokemon like the rock type Iwanko or the cute Koala Pokemon picture above from a Corocoro scan. We'll know more come July 1st at 9am eastern time so stick around and get excited for even more Pokemon fun!
Fairy Tail is coming to Dead or Alive
Anime fans rejoice, a popular series is making it's way to one of the best fighting franchises. In the form of some awesome costumer DLC for the Dead or Alive 5: Last Round title, the series Fairy Tail is making it's debut. The manga series has been running for nearly a decade with an anime series, multiple films, and OVA's to go along with it. Take a look at the new costumes in action, you can pick them up today for the PS4, Xbox One or PC for $31.99 or $2.99 for an individual costume!
The Warcraft film just broke another impressive record
Let me be frank when I say this, Warcraft the film is nearly unwatchable. I, somehow absolutely adored everything Duncan Jones did in the film but only because of my many years spent with the long running Blizzard franchise. If I had no prior knowledge of, well, anything happening in this film, I'd probably have laughed and left disappointed. Despite the very low reviews for the film nearly a decade in the making, Warcraft has gone on to break records in almost everywhere but stateside. As a matter of fact, it's now the highest grossing video game film of all time beating out Prince of Persia. This might not be terribly shocking considering at one point the MMO version of the PC title, World of Warcraft, boasted an incredible 10 million players world wide. The movie's beautiful to look at, regardless of some ridiculous moments and it's an amazing feeling to see these characters and units from the games up on the big screen but for new comers, the movies a bit convoluted. The future is uncertain for the film franchise due to the fact that Warcraft grossed $37 million in the U.S. and over $200 million in China. Whether we'll get to dive back in to one of the most popular franchise has yet to be seen but if you were a fan, (like I oddly was) then keep your fingers crossed.
Okami 2, Bayonetta 3 and more Scalebounds
A lot of interesting games were shown at E3 but one developer wants some sequels to some already popular titles. Co-founder of Platinum games studio, Hideki Kamiya, spoke to UK gaming site Metro about the possibility of continuing on the Bayonetta and Okami franchises. In regards to Bayonetta, Kamiya said "why should it end at 2," as well as "I've got ideas in my head of Okami 2!." He even spoke about 2017's highly anticipated dragon riding Scalebound, stating "We've got other Scalebounds in our heads too." Bayonetta 2 received critical acclaim and the character became popular enough to enter into the 4th installment of the Super Smash Bros franchise. Hopefully all of these games will be coming our way in the next few years but you can read more about Kamiya's comments in the interview here and look at the Scalebound multiplayer footage show at E3 below.
Dead Rising 4 is coming this holiday season
The cheesiest and bloodiest zombie franchise is coming home, just in time for the holidays. Dead Rising 4 was just one of the many surprises at this years E3 and it looks like they're moving back to basics with the latest installment. This time, we'll find original photographer and protagonist Frank West, back in the middle of a Zombie apocalypse during the most wonderful time of year, Christmas. Mayhem and more will surely ensue in this bloody holiday story and thankfully to an early leak on the Xbox store, gamers can expect Dead Rising 4 December 6th, 2016. Watch the new trailer below and get ready for some zombie mayhem, all over again.
See some of the new Pokemon and battle arena mode coming to Pokemon Sun and Moon
After a lengthy live game play of Pokemon Sun and Moon, fans were treated to a new trailer showing off several brand new Pokemon as well as a new multiplayer battle mode as well. Take a look at the trailer below and get excited about all the new Pokemon, feature, and region coming this fall!
Everything from Legend of Zelda to Pokemon from Nintendo's Treehouse
Nintendo began their press event with a message addressing both weekend shootings in Orlando Florida, the other including former voice singer Christina Grimmie who was scheduled to appear at the Nintendo E3 booth this week.
It's time for Nintendo's tree house event and after a disappointing last year, new Zelda, Pokemon and plenty of more surprises will hopefully get gamers excited.
- A new cinematic trailer for the next Legend of Zelda series reveals some truly massive and brilliant looking locations. A close eye will notice a variation of armor and gameplay as well. The official title is, Legend of Zelda: Breathe of the Wild. No female link has been confirmed. The newest title in the series has been described as a open world experience, a first in for the franchise, moving towards a blended Skyrim (in size) with cel shading.
- Next up is an interview with Junichi Masuda regarding this falls upcoming Pokemon Sun and Moon. Professor Kukui is your cousin as addressed by the quick scene of dialogue. (Unless of course its slang) The rest of the footage seems to be a mashup of footage from the previous two trailers that we've seen and nothing new. Solgaleo and Lunala are hinted at having unique roles that are different from previous titles. We have also seen the 10% forme and complete forme of the ground/dragon Zygarde from Pokemon X and Y. The character designs are suppose to reflect the warm climate of the environment in the alola region. We also got our first look at the game play and inside the players house. We get to see a fight between new water starter Popplio against a wild Ledyba. There's a new shadow effect and removal of the platform that use to sit underneath the Pokemon. There's new interface changes for the battle selection screen as well. You'll be able to analyze the opposing Pokemon as well as pull up info on your moves as well. A female yungoos, an angry looking mongoose Pokemon appeared as well. When you approach trainers, a shadow highlights the top and bottom of the screen to alert players. You'll be able to move to in full analog direction this time around as well. A woodpecker Pokemon Pikipek is introduced in the wild. Hala is described as a strong trainer on the island. Pokemon battles with your rival hold a significance on the island, the first being a ritual to head off into the wild. Hau's first Pokemon is a Pichu. His second is the fire/cat Pokemon Litten. Also one of the new starters. Moves are now listed as effective, not effective and etc after facing a Pokemon more than once. A new multiplayer battle mode titled "battle royale," will allow 4 players who can choose up to 3 Pokemon, to battle against one another. The battle ends when one player loses their Pokemon. Customization for outfits has been confirmed as well.
Intermission while waiting for Zelda gameplay
- Bill Trinen is showing the gameplay for the new Legend of Zelda: Breathe of the Wild. Link awakens in a Shrine of Resurrection. Technology will be added as well. There is a large inventory screen allowing gamers to equip and change clothes. A voice over instructs link that he is a light that Hyrule needs. Link will be able to jump as well. You can climb mountains and other structures as well. There will be lots of collectible items that you'll find a long the way. Some you can use for items to cook as well as weapons like tree branches. You can also light things on fire. Weapons will also have durability and can break. The game is anime influenced and ill rely heavily on finding and gathering resources.
Treehouse will be streaming Zelda footage throughout the day so if you don't mind some spoilers, make sure you tune in!

redpajama_set_name: RedPajamaCommonCrawl


I hadn't gotten a chance to work too much with css animation but decided to give it a try on some work today. With a quick stop over at css-tricks to brush up on things and another google on fade-ins I have a new snippet in my inventory. Demo on the gist is a simple ROYGBIV for a pretty demo.


The laboratory for research into Neurodegenerative disorders at VIB in Leuven is looking for a highly motivated postdoc interested in a system approach to understand sporadic Alzheimer's Disease. Alzheimer's Disease is a untreatable neurodegenerative disease affecting 30 million people worldwide.
Unfortunately, the cause of (sporadic) Alzheimer's Disease is poorly understood. Genetics however play a very crucial role as has been demonstrated in extensive genome wide association studies and in twin studies. Literally thousands of loci in the genome influence the risk of Alzheimer's Disease and this is captured in the so called polygenic risk scores (PRS) that allow to predict to a high certainty whether somebody will get Alzheimer's Disease or not.
We are looking for an enthusiastic and creative postdoctoral investigator that wants to work with us to exploit this innovative insight to generate new ways to think about "drugable" pathways in complex disease.
We will focus on mining and understanding the implications of genetic variation in Alzheimer's Disease.
We will generate novel data sets using single cell transcriptomics approaches of human induced pluripotent cell lines generated from patients with different polygenic risk scores.
Experience with the analysis of high-throughput data, including transcriptomics, genomics, and single-cell RNA-seq data.
A strong scientific attitude; you work precisely and meticulous.
Positive, proactive, adaptable, eager to learn.
The ability to further develop yourself as an expert in systems biology in the field of neurodegenerative diseases. The ability to work on high impact, state-of-the-art projects in a stimulating and social international research environment with world-class science.
Please complete the online application procedure and include a detailed CV, a motivation letter describing research interests and previous research experience and a list of publications.
For more information: please contact Mark Fiers.


text:
X. Zimske olimpijske igre su održane 1968. godine u Grenobleu, u Francuskoj.

Po prvi puta je Međunarodni olimpijski odbor dozvolio da Istočna i Zapadna Njemačka nastupe kao potpuno odvojene momčadi, iako su do ovih ZOI nastupali kao združeni tim Njemačke. Ta će se praksa odvojenih nastupa nastaviti sve do ponovnog ujedinjenja Njemačke 1990. godine.

U natjecateljskom programu su se istaknuli sljedeći pojedinci i momčadi:
 Alpski skijaš iz Francuske Jean-Claude Killy je razgalio srca domaćih gledatelja osvojivši zlatne medalje u sve tri tadašnje alpske discipline (slalom, veleslalom, spust).
 Toini Gustafsson, trkačica na skijama iz Švedske, je dominirala s osvojena dva zlata u obje pojedinačne discipline (5 i 10 km) te je tim medaljama pridodala i srebro iz štefete.
 Eugenio Monti iz Italije je ostvario rijedak podvig: kao pilot boba nastupio je i u bobu dvosjedu i u bobu četverosjedu, te u obje trke osvojio zlatnu medalju.
 Po prvi puta od kada se na ZOI uključila momčad SSSR-a neka druga država je bila prva po broju osvojenih medalja. To je ovaj put uspjelo predstavnicima i predstavnicama države Norveške, koja je na taj način za kratko prekinula dominaciju športske velesile SSSR-a na Zimskim igrama.

Popis športova

Popis podjele medalja
(Medalje domaćina posebno istaknute)

Sudačke kontroverze
 U muškom slalomu je Austrijanac Karl Schranz uložio žalbu nakon svog nastupa tvrdeći da mu je tijekom utrke netko od gledatelja namjerno prešao stazom prisilivši ga da potpuno uspori i time ga onemogućio da ostvari dobro vrijeme. Suci su najprije dozvolili Schranzu da ponovi nastup, i on je u ponovljenoj vožnji ostvario najbolje vrijeme. Naknadno je ponovno uložena žalba, ovaj puta od strane domaćina i Shranzu je tada brisan drugi, bolji rezultat te priznata samo prva, daleko sporija vožnja. Kako je time zlato osvojio upravo domaći predstavnik Killy, do danas postoje sumnje u regularnost te utrke.
 U sanjkanju su natjecateljice iz Istočne Njemačke osvojile prvo, drugo i četvrto mjesto. Međutim, sudački žiri ih je naknadno sve tri diskvalificirao, zbog navodnog zagrijavanja sanjki prije starta.

1968
Međunarodna višešportska natjecanja u Francuskoj

redpajama_set_name: RedPajamaWikipedia


OP this is so serious. Please PLEASE press charges! she is dangerous and needs help. and you need support as a victim of an awful crime. you should get compensation. hopefully a good plastic surgeon will be able to fix the initials.
Make sure you introduce her to those assault and battery charges.
but I would recommend getting some counselling or something because this is a horrible experience and traumatic.
And don't forget the lawsuit to cover pain and damages. Reconstructive plastic surgery isn't cheap.
Of course, he'll probably end up having to visit his dedicated girlfriend in prison or the psych ward.
So her boyfriend stood by and watched, did he? Because it sounds like you're saying he was there talking to you when she came along.
To be fair... if he is a rational person? When she came up and did assaulted that poor girl, he may froze.
A lot of people freeze when they witness an attack like that. It's hard to even know where to begin with how awful what happened to her is, let alone actually seeing it.
I hope she gets all the help she needs and the attacker gets the book thrown at her.
I hope this post was the third thing you did after filing charges and contacting a good personal injury attorney.
She needs some time out.
We are here for you OP. Restraining order and press charges to work towards keeping you safe in the future. Prayers for a speedy recovery.
Girl should be in jail!
I feel like this has to be one of the worst FML I have ever read. In seriousness though I hope you pressed charges against her. I hope the plastic surgeon will be able to fix this for you but as for your traumatic experience I hope you will consider getting help in coping with this.
As for this "boyfriend", I really hope he broke it off with his girlfriend after what she did to you because that's a huge red flag for him being in relationship with controlling psycho.
"I feel like this has to be one of the worst FML I have ever read. In seriousness though I "
Wait...so your first sentence was a joke?
"Would you like to know...how I got these scars?"


text:
Will China rule the world?China
What does the new China think of itself?
Shi Yinhong
Traditional ideas are combining with economic self-confidence to create a new and powerful sense of 'Chineseness'
Wed 24 Jun 2009 14.00 EDT
Martin Jacques persuasively argues that a modernising and modernised China will keep its essential and dynamic Chineseness in a new era of "contested modernity", and that the rise of China as both a "civilisation-state" and a nation-state is ending the dominance of the west and ushering in a new era of global diversity in values and power distribution. It is hard to contradict his observation that "contrary to almost universal western expectations after Tiananmen Square in 1989, the Communist party not only survived but reinvented itself and, over the last 30 years, has presided over the most remarkable economic transformation in human history". But his assertion that China's age-old sense of superiority will reassert itself is more controversial.
Throughout China's very long history there has been a persistent theme of continuity and change – the former very tenacious, but the latter sometimes very drastic. Modern China has undergone many major changes. The Chineseness of China is dynamic, shaped not only by traditional ideas of China, but also by contemporary ones.
China's current leaders and, through them, the majority of the Chinese people have a strong belief in Chineseness and its overwhelming importance to national reform and development. This belief in Chineseness is not like the traditional Confucian one, which treated it as a universally applicable value. It is more particular, not assuming that what is best for China is necessarily best for the world. This aspect was introduced by Mao Zedong – before his own revolutionary "universalism" after the 1950s – by his insistence on determining the strategy of the Chinese revolution according to China's particular conditions, and his resistance to the attempts of Comintern to impose a universal revolution.
China's achievements over the past 30 years are a major source of Chinese patriotism today. The success of so-called "socialism with Chinese characteristics" has restored the Chinese people's self-confidence after the disaster of the Cultural Revolution, and in the face of the earlier spectacular success of the west. This self-confidence has now developed in the context of the global financial crisis, which has further dented the west's prestige and increased its dependence upon China. Its effect on China's foreign policy is noticeable.
China is aware that it still faces many challenges: its huge size and population, its domestic problems and the foreign policy situation. But both the Chinese Confucian empire and a China willing to follow the west (whether in the sense of Woodrow Wilson or Lenin) have passed into history, probably never to return.
Will China rule the world?
Tiananmen Square protests 1989
Global recession


The Outside has been unexpectedly strong, but I wanted to stop in and say hello. So, hello!
But I am not in the Basement, which is good, because it looks like a scary place.
Ch*rp, I'm Pope. Um, post about scary things? Or basements?
Nobody has basements here in California. I wish I had a basement. So much room for activities.
Jose was so restrained as he did what storms do.
Jose? Did you have influence on your namesake?
Maria!! She has been very scary.
"The Sea is Big and does what it wants."
I don't, really, understand those words.
I feel like a child listening to adults.
The adults seem to be sober and take it seriously.
So; I will try to be stoic and take it seriously.
This is a serious year for people near the sea.
That's one saga complete, two more series to go.
addams wrote: "The Sea is Big and does what it wants."
Back in the Dix of Time, religions grew up around Holy Words like these. But if you follow Acts of the Clerics, wait for it.
But the sea really is big. It must know what it's doing.
That was such a long Time ago.
I was inexplicably logged out of the fora and I'm seeing a 'connection not secure' warning in my browser due to a lack of https. Any idea why this is?
Didn't we have https before?
Eternal Density wrote: Didn't we have https before?
Here in Germany houses almost always have basements. In old houses they are invariably musty and moldy. Our forefathers, who did not have refrigerators, preferred a cool and slightly damp environment for the storage of various kinds of food.
FTH: Ah, the wonderful system of edukacja.CL.
"No more filling out papers.
You can acomplish everything through the internet."
B: That's true, technically... Only that later you have to print it and bring to them physically, even though they have it in their system.
B: There is one thing they did right. Signing up for things.
Is there even a plan?
Yeah. But that's what the first part of making a plan looks like.
I think I 'Get It'.
Please, come back with stories for us.
Eternal Density wrote: I was inexplicably logged out of the fora and I'm seeing a 'connection not secure' warning in my browser due to a lack of https. Any idea why this is?
Gee...Maybe, someone is fighting off Hackers for us.
I have had problems with 'Lock-Up'. So far, I can fix it.
That is a scary thing.
I am helpless against Hackers.
oh, oh. Here is another scary thing.
to ripen tomatoes. Very Unusual!
This year's harvest. Tomatoes that look like flowers.
I was really very pleased.
They were sweet with lots of meat.
My HummingBird has a friend!
Now, there are two little birds.
And; There has been enough rain to really slow down the fires.
Fire Season may be over for this year.
My previous location was a cold-winter environment with a deep frost line, hence most houses had basements.
Now I live in a place without them, which may explain the large market for storm shelters around here.
thunk wrote: My previous location was a cold-winter environment with a deep frost line, hence most houses had basements.
If you are a private person you can tell us longitude and land mass.
I, just, can't imagine...We don't have deep frost nor storm shelters.
She had a storm shelter.
Not the One True Thread, but a needle pulled thing nonetheless.
But not the One True Thread, surely.
I know, I know, don't call you Shirley.
Somewhere the word "ineffable" came up, and I was reminded of a discussion, way back in Time. Someone described something that GLR did as "ineffable," and since we were all confused about what was happening in Time, someone else said it was "in-what-the effable." That lead me to thinking (sometimes a dangerous thing), that you hear the word ineffable, but you don't really hear the word effable. And that led me to think about the fact that nowadips, if someone heard you say someone was "effable," they would have a very different idea about what you meant.
Oh, for decree, hm. It's sometimes scary the random railcastles of thought that fill my head. Also, I grew up with basements, and now live in California where there are none. Like Pfhorrest said, I miss having a basement.
In other news, I will be having a most blessed audience with our Pope of the Holy Contradiction. It will involve the First Commandment for both of us, I think--him waiting for me to arrive, and me waiting for traffic to move. But I am Waiting for It eagerly nonetheless.
Funny story: When TGWFP was a teenager, she decided she was going to be a vegetarian. One time, we were out and about and needed to get lunch at a deli. She found a tomato sandwich that was acceptable. Then she noticed that it was "Beefsteak Tomato" I did manage to convince her that there was no steak in the tomato.
GLR wrote: I'll be visiting the UK next week! You can join me in London from September 30-October 2 (at New Scientist Live, The Royal Institution, and Intelligence Squared), then from October 3-6 in York, Edinburgh, Cambridge and Ely, Oxford, and Cheltenham.
addams wrote: I give up. Where in The World are you? If you are a private person you can tell us longitude and land mass.
By longitude I imagine you mean latitude. Neither longitude nor latitude would answer the question, rather it would give unrelated information that would let you greatly reduce the uncertainty in @thunk's former and present positions. But you could get to the point by asking about mean high and low temperatures during the coldest month.
In this map of the U.S. the no-Basement locations are south of the 10" line, and the Basement-almost-always locations are around the 20" and 25" lines.
I meant and should have typed latitude.
I apologise for being rude and patronising. Re-reading my post, it looks like I was being really nasty. By Randall, I was tired.
I also should have mentioned that the "storm shelter" part of @thunk's comment suggests a location that has tornadoes or tropical cyclones (also called hurricanes or typhoons). There are a several U.S. states on the map south of the 10" line that would qualify.
The frost line depths closely correspond to mean temperatures during the coldest month. Here is a world map. But I don't know if there are other countries that use monolithic foundations the way they do in the U.S.
lmjb1964 wrote: But not the One True Thread, surely.
That sounds like a lot of fun aside from the traffic.
I mean, I called myself Anne, so Shirley isn't too far out of the way.
I invite you to take a look at the title of my previous post.
mrob27 wrote: I apologise for being rude and patronising. Re-reading my post, it looks like I was being really nasty. By Randall, I was tired.
That didn't seem nasty at all, and only vaguely patronising.
The town I live in was built in a flood plain, so most of the the basements are only half buried, and they tend to have low ceilings. Even so, people with finished basements have to replace their carpeting and drywall every few years when they fill with water.
Oh, Dear! mrob; I was not offended!
I was busy reading your links and thinking.
I was thinking about the cold.
Cold that can reach four feet into the Earth!
...It was unusually cold here last year.
The soil in my flower pots was like rock.
That kind of cold frightens me.
I was wondering about buildings heaving Up out of the ground.
The basements act like anchors?
Is that the point you are pointing out?
Thunk must live in Tornado Alley.
Everyplace has its Natural Disasters.
Here, we chat about our Tsunami routes.
I live at about 15 feet above sea level.
I moved out of the forest.
There I was at 500 feet.
What Natural Disaster Threat do you live with?
You get Tornados and Wet Carpet.
That is steady work for people that work on buildings.
Well...not really I don't think? While convective initiation of severe weather does tend to result from instability of air masses (and by extension, large vertical temperature gradients), factors in deep desert basins aren't usually the most tornado-conducive. First of all there would be a lot of subsidence (in this case down to the 1300 hPa level), which 1)tends to dry air masses substantially, and b)make them more stable as the moist-adiabatic temperature gradient is less than the dry-adiabatic one (and they're vertically compressed, lowering the lapse rate still further).
Second, the dry conditions at the bottom of the Mediterranean basin and again, the subsidence would make the lifted condensation level, and thus the cloud base very high. This is the opposite of conditions in which tornadoes form; it's really closer to dry-microburst conditions, if anything.
Third, supercellular tornadoes also require substantial wind shear, which is caused by variations in the jet stream and extratropical cyclones. Most of these tend to pass north of the area, but plenty of tornadoes have been recorded in Italy, so I guess that last factor is possible.
In short, probably not, though I don't think any numerical simulations or detailed research have been done.
B: You can print whatever you need at my place.
Then you're free to go to the city.
But now it makes sense to return home with you.
FTH: I don't feel good about interrupting you here.
I can give you the key. What do you think?
Is KxA uncomfortable taking his key, or does she just want to hang out here for now and look for the object generator?
Following up on my previous comment, Murphy et al., 2009 suggest that the dry Mediterranean during the Messinian pushed the jet stream further to the south due to orographic effects, which probably negates point 3. There was also a substantial amount of ascent at the north side of the basin and consequent increased precipitation (also found in the paleoclimate proxies from the time), so I can definitely see convective initiation and tornadic thunderstorms in Beanie-land, though likely not in the basin itself.
As Murphy notes, surface temperature increases would be less than that naively assumed from the lapse rate above, as the surface energy flux is constant. There's still a modelled 10-15 C increase though. Speranza et al. 2013 suggest lower SSTs during the dessicated stage similar to today's values, likely because that was in the middle of a glacial period, not likely to be present in 13 ka from now in the Time Universe.
Incidentally, Lazar et al. 2012 also suggest 'massive gas escapes' from the basin while its sea level was low, leading to 'giant pockmarks' at the surface resulting from destablization of gas deposits. I'd love to see the cueganites make a note of that.
addams wrote: Jose was so restrained as he did what storms do.
I danced with Maria, hoping to keep her on the ballroom floor rather than heading for the shoreline. Dunno how well I succeeded; hurricanes are made of the sea.
lmjb1964 wrote: In other news, I will be having a most blessed audience with our Pope of the Holy Contradiction.
Waiting for it has its awesomeful rewards! I would love to report that, indeed, an Agent of R.A.Z.O.R. gave the proper countersign when presented with the appropriate code phrase, and that wingish and trancendental audience was had. But since there's no such thing as R.A.Z.O.R., such a meeting could not possibly have happened. Which is a Holy Contradiction, whose implications are well known. It would even be possible that there was a third person involved, occasionally wielding devices of organized light, were there such an organization having such a meeting. If the First Commandment is followed, organized light might hit organized sand, proving that no such meeting ever took place, and that no such organization even exists, and no insect of the sixth heretical month is a member.
It was glorious. You know what to do.
SBN wrote: Then she noticed that it was "Beefsteak Tomato" I did manage to convince her that there was no steak in the tomato.
I'm still not sure whether a "chicken steak" is a steak or a chicken. Or an inorganic non-meat food product item.
GnomeAnne wrote: That sounds like a lot of fun aside from the traffic.
Actually traffic was molpish, at least on my end. Finding parking was mustardy. Finding each other was marvelous!
GnomeAnne wrote: I mean, I called myself Anne, so Shirley isn't too far out of the way.
Thinking of a prior post of yours, I read this as "Tomato Alley".
quoting B, Balthasar_s wrote: You can print whatever you need at my place.
Can I print twenty-dollar bills?
thunk wrote: Incidentally, Lazar et al. 2012 also suggest 'massive gas escapes' from the basin while its sea level was low, leading to 'giant pockmarks' at the surface resulting from destablization of gas deposits. I'd love to see the cueganites make a note of that.
It would be a low D-flat, I'd say.
GnomeAnne wrote: Is KxA uncomfortable taking his key, or does she just want to hang out here for now and look for the object generator?
From what you know about her so fat - whad do you think is more likely?
Also, some of the recent frames contain some information about her.
Fun fact: If you live in a place that has deep ground freezes (and thus, house with a basement) and if you also have flooding (like @GnomeAnne mentioned), and if you logically decide to try to waterseal the basement somehow, the foundation must be mechanically anchored (e.g. with protruding horizontal extensions well below ground level). Why? Because your basement might act like a boat and float on the water table, lifting your entire house up!
Tony Bryan wrote: The high groundwater level […] induces bouyancy in the basement. While this buoyancy may be overcome by the full weight of the finished building, a partially constructed building may not be of sufficient weight, so the basement may float upwards.
TL;DR: In Zanclean times, a Basement makes your home into a Raftcastle!
SBN; I love your stories.
It made me chuckle as I watered.
lmjb1964 wins the All Time First Prize for MeatSpace Meet-Ups.
Was East Indian Food involved?
That seems to be Traditional.
I am a tired Poster.
I've been painting everything, except the flowers, Red.
addams wrote: Was East Indian Food involved?
Not unless Vietnam is a part of East India. And of course June Bug wins the prize - as a steadfast and stalwart agent of RAZOR it is obviously part of her mission to get to know as many OTTers as she can, to ensure that... wait a minute - there's no such thing as RAZOR. That meeting never happened. You are not reading this post. In fact this post doesn't exist.
The food was delicious though, and the company was quite molpish!
Kieryn's back! Or at least his penguins are! Still eleven days of waiting for it, but the sitemustard has been vanquished.
Making someone get my username wrong is a brick joke that's been hanging in the air for at least a decade. I did of course choose it as a reference to George McFly saying density instead of destiny in Back to the Future, so it's by design.
Eternal Density wrote: Making someone get my username wrong is a brick joke that's been hanging in the air for at least a decade.
Hanging in the air?? I had it wrong for... well, it seems like yips but it was only a portion of Time. Long enough anyway. There might even be evidence.
Re: 158: "Rossby wave amplification"
KXA: I would like to stay here.
Could someone tell me what's going on here?
B: I received a file. It lists this place as an object generator location.
FTH: And that's why you're here?
B: Yes. I decided to go and take a look around here even though I know this place.
FTH: And you wanted to join him in this.
KXA: Yes. You don't have such an opportunity every day.
FTH: Ok, whatever. Just be careful.


text:
Q: How to fill missing date by Pandas I am using python/pandas to process time series data in the following foramt:
index, date, name, value
1, 01/05/2017, x, 1.1
2, 05/06/2017, x, 2.3
3, , x, 5.4

On line 3, the date is missing. My question is if Pandas can fill the missing date by some algorithm (like interpolate, extrapolate, etc.)

A: I can think of two methods that should be helpful in your case:
1- Using the fillna() method in pandas
2- Using the Imputer class in scikit-learn

redpajama_set_name: RedPajamaStackExchange


text:
Darkinjung Barker
Dhupuma Barker
Ngarralingayil Barker
The Garma Festival 2022
The Garma Festival is an annual festival held in Gulkula, North-East Arnhem Land, which returned in 2022 after a COVID induced hiatus of two years.
It is an internationally reknowned Indigenous event, a coming together of more than 3000 people from across the nation that celebrates the cultural, artistic and ceremonial traditions of the Yolŋu people of North-East Arnhem land. Barker already has a deep connection with the Yolŋu people though our school, Dhupuma Barker, and in late July we had the great privilege of attending the Garma Festival with a contingent of 16 students and supporting staff. It was an incredible opportunity for the Barker Hornsby community to engage with the Yolŋu nation and continue to strengthen our relationship with the Gunyangara community. Students and staff spent four days camping in remote Arnhem Land, immersed in the rich cultural heritage of the Yolŋu people experiencing traditional miny'tji (art), ancient story-telling, manikay (song) and bunggul (dance). A reflection of our experience will be included in the next edition of The Barker. Manymak!
By DarkinjungAdmin | 01 September 2022 | 2022
About the Author : DarkinjungAdmin
RESPECT AND RECOGNITION
We acknowledge the Darkinjung people who are the traditional custodians of the land on which Darkinjung Barker stands. We pay respect to the Elders past and present and to our youth who are the future leaders of the Darkinjung nation.
We acknowledge the Wonnarua people who are the traditional custodians of the land on which Ngarralingayil Barker stands. We pay respect to their Elders past and present, and to the young people who are the future leaders of the Wonnarua and other nations.
We acknowledge the Yolŋu people who are the traditional custodians of the land on which Dhupuma Barker stands. We pay respect to their Elders past and present, and to the children and young people who will carry their matha, rom and galtha into the future.
We extend our respect to other Aboriginal and Torres Strait Islander people within our Barker communities.
Phone:8438 7000
Email: mshaw@barker.nsw.edu.au
Copyright 2023 Barker College


The certificate of achievement is the highest form of recognition in the area of governmental accounting and financial reporting and its attainment represents a significant accomplishment by a government and its management.
The GFOA established the Certificate of Achievement for Excellence in Financial Reporting Program in 1945 to encourage and assist state and local governments to go beyond the minimum requirements of generally accepted accounting principles to prepare comprehensive annual financial reports that evidence the spirit of transparency and full disclosure, and recognize individual governments that succeed in achieving that goal.
Participating in the GFOA helps Tampa Bay Water maintain its place as a respected member of the Tampa Bay community by ensuring transparent communications with its member governments and stakeholders regarding financial accountability.
Created in 1998 as a true regional water utility, Tampa Bay Water is the largest wholesale water supplier in Florida. Providing high-quality drinking water for more than 2.5 million residents of the Tampa Bay area, Tampa Bay Water is the result of collaboration among its member governments, which include the cities of New Port Richey, St. Petersburg and Tampa, and the counties of Hillsborough, Pasco and Pinellas. For more information, visit www.tampabaywater.org.
The Government Finance Officers Association is a major professional association servicing the needs of nearly 19,000 appointed and elected local, state, and provincial-level government officials and other finance practitioners. It provides top quality publications, training programs, services and produces designed to enhance the skills and performance of those responsible for government finance policy and management.


For many, a trip to Antarctica, the seventh continent, is the ultimate bucket list adventure. Cruising through the oceans to dock at remote harbors where king penguin colonies nest or where whales breach in the waters along the Antarctic Convergence is an increasingly popular experience.
Cycling tours through India are becoming a popular way of ticking off bucket list destinations while enjoying an active break in one of the world's most diverse and picturesque countries.


The Division 2 is an addictive, highly rewarding experience. Bugs exist, but overall it's a highly polished experience.
Most people play loot-driven games like The Division 2 for the endgame content. That's understandable, as it features the best gear and the most difficult challenges. But I can still wholeheartedly recommend The Division 2 if you have zero interest in the endgame. That's because Ubisoft has made the grind far more enjoyable and varied this time around.
Rather than placing each mission in nondescript buildings with no core identity, Ubisoft has made each level its own vibrant set piece completely unique to the rest of the game. In one mission, you explore the American History Museum, filled with interesting exhibits that we won't spoil here. In another mission, you're off to the Space Administration HQ before trekking over to the Lincoln Memorial to shoot baddies inside a museum dedicated to the monumental president.
Each of the story missions uses its environments to tweak the core gameplay loop just enough to get you to think on the fly. For example, in the aerospace museum, I entered a planetarium. But I initially didn't have time to admire the constellations moving around the top of the darkened room. My enemies had taken position in a blown out opening in the dome above, and with the ceiling moving, their visibility and position constantly changed.
Getting a good read on them required me to move strategically from my position below, all the while monitoring additional threats on my level.


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Q: Ubuntu 14.04.3 LTS not Starts GUI I installed Ubuntu 14.04.3 LTS on my HP Pavilion G4 1115br and when I start it does not load the GUI: Ubuntu 14.04.3 LTS problem in not Loads GUI - Part 1/2. After I shut it down manually and start appears Grub and only then the GUI is loaded: Ubuntu 14.04.3 LTS problem in not Loads GUI - Part 2/2.
Comments:

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*The system is installed from a Live USB.

*What is more funny is that in the previous version, the 14.04 without
update for 14.04.3, Ubuntu ran quiet. I had put Fedora 22 with the 64-bit architecture and also ran quiet.

*System is light, it is only with this problem even at the time of boot, the rest runs beautifully.
The Graphics settings from my notebook are:

*

*Processor: VISION A4 Technology from AMD with AMD accelerated two A4-3300M cores (2.5 GHz / 1.9 GHz, 2 MB L2 cache)

*Processor Architecture: 64-bit

*Memory RAM: 3 GB DDR3 System Memory (2 DIMM)

*HD: 500GB (5400 RPM)

*Video Card: Radeon HD 6470G2 Dual AMD with 512MB of DDR3

*Screen: HP BrightView LED Display 14.0 "HD (1366 x 768)