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# Waves - Science topic

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Dear ResearchGate members,
On one hand, there is a theory giving the reflection/transmission coefficients when acoustic planes waves propagating in a medium (rho0, c0) reach a finite thickness object (rho1, c1) with normal incidence. Such theory basically gives the thicknesses (n*lambda1/2) at which the object is theoretically acoustically transparent - of course, the width of the reduced reflection depends on the impedance mismatch between the 2 media – and the thicknesses ([2n-1]*lambda1/4) at which the object is fully reflective.
On the other hand, there is also theory giving the variation of the reflection coefficient depending on the incident angle of acoustic plane waves at the interface between two semi-infinite media (rho0, c0; rho1, c1). Over a critical angle (depending on the impedance mismatch between the two media), the reflection is theoretically total.
Now, here is my question: What is the behavior of the acoustic waves when the two phenomena are considered at the same time? If the plane waves reach a surface with an incident angle, and the reflective medium is finite in thickness (acoustic mirror)?
By experience and through simulations, it appears that over the critical angle, the reflection is not total, even with a mirror thickness for which the reflection is theoretically total.
The second part of your question was too complex. I submitted some supplemental info.
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I have a finite array of unit cells, completely backed with PEC. When I try to illuminate it with incident plane wave, I get strong scattered waves from the PEC, apart from scattering at desired directions. But the PEC at the back of the metasurface is supposed to block transmission of the incident wave. Still I get strong far field scattering.
I used both open boundary and FE-BI boundaries for the whole metasurface array for this this purpose with no positive results.
Kindly help me.
The total field is the sum of the incident field and the scattered field. The incident field would have continued past place where the PEC layer is. When the PEC is in the way there is no field there, it is is in shadow. Part of the scattered field is the field that cancels the incident field to give zero or lower field in the shadow. For this reason there is scattered field behind PEC.
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If I want to assign anisotropic properties to rocks in the surrounding area of the tunnel when I carry out 2D-seismic wave forward simulation based on the elastic wave equation to explore the impact of shear source on seismic waves, how can I achieve this in Python? Is it reasonable to use np.random.rand() to randomly distribute the density, P-wave velocity, and S-wave velocity of the medium in this region?
Anisotropy is the property of a material that makes it have different physical or electromagnetic characteristics in different directions. For example, an anisotropic material may have different electrical conductivity, magnetic permeability, or optical refractive index along different axes. Anisotropy can affect the propagation of electromagnetic waves in a medium, such as light, radio, or controlled-source electromagnetic (CSEM) signals.
To assign local anisotropy attributes to forward models, you need to specify the direction and magnitude of the anisotropy for each element or region of the model. Depending on the type of anisotropy and the modeling method you use, there are different ways to do this. Here are some examples:
• If you use a finite-element method (FEM) to model optical anisotropic media, you can use the COMSOL Multiphysics® software to define the anisotropy tensor for each element of the mesh. The anisotropy tensor is a matrix that describes how the electric displacement vector relates to the electric field vector in a medium. You can also use the COMSOL Multiphysics® software to perform a mode analysis and visualize the optical modes and dispersion curve of the anisotropic medium. For more details, you can refer to this link.
• If you use a FEM to model CSEM signals in anisotropic media, you can use an adaptive edge-based FEM algorithm to deal with generally anisotropic conductive media. This algorithm uses unstructured tetrahedral grids that allow for complex model geometries and adaptive mesh refinement that controls the accuracy of the solution. You can also use this algorithm to investigate the effect of azimuthal anisotropy on frequency-domain CSEM responses. For more details, you can refer to this link.
• If you use A-Frame to create 3D scenes with textures, you can use a custom component to set the anisotropy filtering value on A-Frame textures. Anisotropy filtering is a technique that improves the quality and sharpness of textures when viewed at oblique angles. You can use this component to modify the texture properties of any A-Frame entity that has a material component. For more details, you can refer to this link.
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The Covid shock
Covid19 caught us by surprise. The previous comparable event had happened 100 years earlier and it had been named the Spanish flu, and it probably killed more people than World War I. The 1919 lessons learnt by health policy makers such as the US cities and European governments had been long forgotten.
Now we have learnt something
This time, it's 2023, and the Covid years, which are not over, have left a clear memory. We have no excuse, not to go prepared.
What about behavioural economists, looking at the exchange of value, time, tasks, anything, in human groups?
What can they tell us, of practical and explanatory interest for the next wave of Covid, or ahead of a similar event?
Behavioural economics scenarios and the pandemic
Can I suggest to look back at the micro-problem replicated a large number of times worldwide, where each household had to self-manage meals, schooling the children, etc. Trade-offs happened at high frequency between the members of the household, seen as agents in a behavioral nano-economy of the house...
The behavioual economist and a vademecum for the next wave?
What do you consider worthwhile for planning the next wave each household likely to have to isolate for while, at least now and then?
Let me share the assessment and model developed for the case of Covid19 "household lockdown":
REF
[1] Agent Based Model for Covid 19 Transmission: -field approach based on context of interaction, July 2020,R. Di Francesco, DOI: 10.13140/RG.2.2.24583.83364
[2] "Nanoeconomics of Households in Lockdown Using Agent Models during COVID-19," Sustainability, by Javier Cifuentes-Faura & Renaud Di Francesco, 2022, vol. 14(4), pages 1, February.
[3] Microeconomics of intertemporal choice in zero-space during Covid-19: a behavioral economics perspective. by Cifuentes-Faura, J., Di Francesco, R., J Health Econ 23, 559–563 (2022). https://doi.org/10.1007/s10198-021-01403-z
Behavioural economics must explore the limits of its altruistic paradigm while shedding light on the relationship between laboratory kindness and everyday egoism. The notion of a deeply rooted do-gooderism may indeed flatter our hearts, but it must cloud our understanding of human action in these difficult times (Citation from last source).
___________
Conclusion:
Choice architecture seems to be central concept (vademecum) from behavioral economics, i.e. monetary compensations do matter in this respect, in terms of effective decision-making.
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The Sagnac effect is a very well known phenomenon considered nowadays in several commercial applications from Laser Gyros to GPS.
This quite recent paper shows that the Sagnac effect can be derived only with absolute simultaniety in the LAB frame https://arxiv.org/pdf/2106.09537.pdf
A moving detector, installed in a spinning closed loop, detects non simultaneously EM waves emitted in opposite directions along the loop.
Sagnac's ingenious experiment in 1913 used a complicated set of mirrors with a beam splitter and an interferometer, set in rotation, to detect the non simultaneous arrival of the EMwaves of a known same wavelength along opposite paths (bouncing on the same mirrors).
The value found by Sagnac, in terms of the variation of the phase at the rotating interferometer, corresponds to the following tested formula:
(1) Δϕ=4πAω / λc
• ​A is the area enclosed by the light path (for a circle, 2A=πr^2).
• ω is the angular velocity of the rotation.
• λ is the wavelength of the light, c is the speed of light in vacuum.
The interval of time between the arrivals of the beams is easily obtained:
(2) Δt=4Aω /c2
In term of the instantaneous speed v of the interferometer and L the length of the path, it becomes
(3) Δt=2Lv/c2
verified for a generic loop of length L [1].
It is important to notice that the exact formulas rely on considerations relevant to relativity.
Eq.(3) is a first order approximation of
(4) Δt=2 γ2vL/c2 relevant to the time measured by the stationary observer
or
(5) Δt=2γvL/c2 relevant to the time measure by a comoving clock with the interferometer.
Considering the contribution to the variation of the time for one wave alone
(6) Δt= γvL/c2
This is also the generic additional light-time of a wave to reach a moving target positioned at distance L from the source, when the wave was emitted.
It means that by varying the position of the target between emission and absorption, light has to cross a different path length than L, hence the time to connect the same objects at constant speed differs by γvL/c2
• An important conclusion from Sagnac experiment is that the speed of light is independent from the speed of the source (wave behaviour)
• A second important conclusion is that SOL measured in a loop (2 way) is c, provided that the loop does not spin. The measured light time differs from the one at rest by γvL/c2
The measured of SOL by a moving observer who assumes that path of light to connect the clocks is always L, it would become by
SOL+ = DS/Dt = L/(L/c-vL/c2 ) = c/(1-v/c).
Eq. (6) shows evidence of the term in time transformations of LT
t'=γt - γvx/c2
where the second term, as shown above, is the due to the variation of the light-time due to the motion of the object in the frame where light is isotropic. In this case one frame is preferred in the problem.
Einstein's requirement according to which the SOL must isotropic in every inertial frame, compels instead the clocks in the new frame to an offset, necessary to make the frames equivalent.
The two views are quite different and Sagnac effect discriminates between the two, showing a way to find experimentally the term γvx/c2 and reveal its actual Lorentzian nature: if SOL is isotropic in one frame it cannot be the same in relative moving frames.
[1] Ruyong Wang et al, “Modified Sagnac experiment for measuring travel-time difference between counter-propagating light beams in a uniformly moving fiber”, Physics Letters A 312 (2003) 7-10, DOI:10.1016/S0375-9601(03)00575-9. https://core.ac.uk/download/pdf/44141186.pdf
I think we mostly agree this time except for a few things.
One problem is that sometimes you state inconsistent explanations.
For instance, you cannot prove that SRT is incorrect because it assumes that light speed is isotropic. That is an assumption that should be proved wrong with experiments, not by assuming the contrary.
There is no experimental evidence to assume anisotropy of the speed of light and the existence of an ether. That is why SRT is accepted to this very day by the orthodox scientific community.
On the other hand, to make sense of Lorentz's interpretation we need a preferred frame. That frame is the frame where the ether is static. The problem with the ether hypothesis is that it is not consistent with observations. But to understand that it is inconsistent with observations you need more than one single experiment. You can always accommodate things to explain a single experiment but not to explain all of them.
Perhaps TT does not use an ether frame and it is different from Lorentz's interpretation, I do not know. But if that is the case, I will repeat a question I already asked you before. How and on what physical hypothesis do you derive the TT? Or, is it just an ad hoc modification of the LT just to eliminate ROS?
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I know AMC resonant frequency at phase 0 ! I read many paper, some AMC S11 are near 0 dB some are below -10 dB. I want to know which is correct ?
My point of view is near 0 dB, because AMC is for reflecting the wave in phase. That the reason why antenna gain rise !
Is AMC only for gain increasing ?
It is better to design AMCs which have S11 values nearly equals to 1 or 0 dB. AMCs are widely used for the design of metasurfaces. Their application areas are not limited to gain enhancement only.
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In relativity (GTR, STR) we hear of masslessness. What is the meaning of it with respect to really (not merely measurementally) existent particles / waves?
I am of the opinion that, while propagating, naturally, wavicles have mass, and there is no situation where they are absolutely at rest or at rest mass. But we know that there are zero rest masses in physics. These are in my opinion masses obtained when the moving wavicle is relatively at rest. Thus, the energy here is supposed to be at a relative zero.
But such a relative rest is obtainable only with respect to a few movements (under consideration at a given relativistic situation); and always there will be some other physical processes around and within, with respect to which the zero rest mass wavicle already contextually taken as in zero rest mass is not at zero rest mass and zero energy.
If the relatively achieved zero rest mass and/or non-zero mass may always be conceived as the real mass, then nothing has a constant and permanent "own mass". In that case, any specific contextual mass must be fixed for contexts only, and the only thing that may be spoken of its mass is "finite", "non-zero and non-infinite".
This is a thing I have been thinking of giving as a realistic example for a method that I had developed in my 2018 book, in order to characterize the various, most general, accessible values attributable to processes. This is what I have called the maximal-medial-minimal (MMM) method of determining cosmological, physical, and other forms of access values of existent processes.
But I forgot to write down the said example. Recently I wrote it down as an example for discussing it in another book. But I realize that I can write a detailed section of a chapter about it.
The MMM method is based on determining the space, time, matter-energy content, etc. of anything, including the whole cosmos, as being of infinite or finite or zero value of any quantity. I have shown in the said book that this can be developed not only into a method in the philosophy of physics but also in the most general foundational notions and principles of all sciences.
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How is the polarization of an em wave change when propagating through fog or rain? Say the wave is initially vertically polarized, how will rain and fog change its polarization?
The polarization of an electromagnetic wave can be affected by rain and fog. Raindrops and fog droplets act as small dipoles, which means that they have a positive and negative charge. When an electromagnetic wave passes through rain or fog, the dipoles in the droplets interact with the wave and cause the wave's polarization to be changed.
The amount of change in polarization depends on the wavelength of the wave, the size of the droplets, and the density of the rain or fog. For shorter wavelengths, such as visible light, the change in polarization is more significant. For longer wavelengths, such as radio waves, the change in polarization is less significant.
The direction of the change in polarization depends on the orientation of the dipoles in the droplets. If the dipoles are randomly oriented, then the polarization of the wave will be randomly scattered. However, if the dipoles are aligned in a particular direction, then the polarization of the wave will be aligned in that direction.
For example, if a vertically polarized wave passes through rain or fog, the droplets will tend to rotate the wave's polarization to a horizontal direction. This is because the dipoles in the droplets are aligned horizontally, and they interact with the wave's electric field in a way that rotates the polarization.
The effect of rain and fog on polarization can be used to our advantage. For example, it can be used to improve the reception of radio waves. Radio waves are typically polarized horizontally, so if they pass through rain or fog, the polarization will be rotated to a vertical direction. This can be used to improve the reception of radio waves by using a vertical antenna.
The effect of rain and fog on polarization can also be used to study the properties of rain and fog. For example, by measuring the amount of change in polarization, we can learn about the size and density of the droplets. This information can be used to improve our understanding of rain and fog formation and behavior.
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Electromagnetic rays emitted from mobile phone towers
There is currently no strong evidence that the waves emitted by mobile phone towers cause cancer. The waves emitted by these towers are called radiofrequency (RF) waves, and they are a form of non-ionizing radiation. Non-ionizing radiation does not have enough energy to break chemical bonds in DNA, which is how ionizing radiation, such as gamma rays and X-rays, can cause cancer.
There have been some studies that have looked at the possible link between RF radiation and cancer, but the results have been mixed. Some studies have found a small increase in the risk of certain types of cancer, such as brain tumors, in people who are exposed to high levels of RF radiation. However, other studies have not found any such link.
The International Agency for Research on Cancer (IARC), which is part of the World Health Organization, has classified RF radiation as "possibly carcinogenic to humans". This classification is based on the limited evidence that suggests a possible increase in the risk of brain tumors among cell phone users. However, it is important to note that the IARC also states that more research is needed to confirm this link.
Overall, the current evidence does not suggest that the waves emitted by mobile phone towers cause cancer. However, more research is still needed to fully understand the possible risks. If you are concerned about the possible health effects of RF radiation, you can talk to your doctor.
Here are some additional things to keep in mind:
• The amount of RF radiation you are exposed to from a mobile phone tower depends on how close you are to the tower, the power of the tower, and the orientation of the antenna.
• You are more likely to be exposed to higher levels of RF radiation if you live or work near a mobile phone tower.
• The risk of cancer from RF radiation is thought to be greatest for people who are exposed to high levels of radiation over a long period of time.
• There are other factors that can increase your risk of cancer, such as smoking, exposure to chemicals, and family history.
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There are two different waves of the gravitational field (GF):
1. Gravitational field transverse wave. What it reflects is the disturbance of the surrounding GF, and the transmission speed of this disturbance is equal to the slow light speed c. For example, the motion of the sun disturbs the GF generated by the center of the galaxy, causing transverse waves of GF around the sun.
2. Gravitational field longitudinal wave. It is generated by the gravitational source itself, and GF will transfer energy quickly, and this speed is much greater than the speed of light c.
When the gravitational source changes (position, mass), this change will first be reflected on the longitudinal wave of GF, and distant objects will feel the change of GF soon. At the same time, the disturbance of the gravitational source to other surrounding GFs will propagate to the surroundings at a slow speed c in the form of transverse waves.
To make an inappropriate analogy: when you throw a stone into a calm lake, you will observe slow water waves spreading around, which is the disturbance of the stone to the water surface, thus generating water waves. But in addition to water waves, there are sound waves in the water. The speed of the sound waves is much faster than that of the water waves, and the sound waves in the water arrive long before the slow water waves reach the shore.
A brief summary: the longitudinal wave of GF is produced by the gravitational source itself, and the transverse wave of GF is produced by the disturbance of the gravitational source to other surrounding GFs.
Newtonian gravity studies "sound waves in water", the longitudinal waves of GF.
Einstein GR studies the "water wave", that is, the transverse wave of GF.
I hope that you can understand the whole gravity from my simple narrative. You can also download my two papers on gravity here:
Kind regards,
Tony
Dear Tony Tony Yuan ,
It is not necessary to talk about things that are intangible no one can verify it.
Here is the gravity wave:
(only hungarian version)
and graviton:
are related to specific facts
Regards,
Laszlo
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Light has a dual nature, on one hand it behaves as a wave (Young's double slit experiment) and on the other hand it behaves as a particle (Photoelectric effect), somehow it is acting as both a wave as well as particle.
So why mother nature has chosen the things to work this way ? what could be the reason for a dual nature of radiation and matter? was it a necessity? why not single unique nature persist? Was it the only way to make the universe work the way it is doing?
Frank
Dont understand criptic remarks.
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It is very likely that it is none of this?
The question arises, does the answer to the question belong to "Shut up and calculate"?
the nature of the wave function can depend upon the physics of the particle or the particles you are describing
if for example, there is a spin 1/2 particle, and coupling to any other "magnetic" field or spin, then instead of there being a simple complex number, the "value" is a spinor
Likewise, a system can be written as having explicit time dependence, or one can limit themselves to wavefunctions which at least mostly seem to be time-independent. So if you have a simple complex "Psi", depending upon the physics being described, the wave function could be a function of x,y,z or else it could be a function of x,y,z,t
Thus, the common simpler wave function of a complex variable defined over x,y,z is probably implicitly dealing with a single particle, no spin or magnetism, maybe no charge or detailed E-fields, and looking for the time-independent kinds of solutions. Huge numbers of physics or chemistry problems where we would use quantum do not fit that simple scenario at all.
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I am processing buoy data where two GNSS buoys are separated by about hundreds of metres, and when performing wave direction spectrum analysis, I find that the dominant directions of the two buoys sometimes differ by about 180 degrees, what is the reason for this?
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We assume that the statistical matrix definition of the quantum wave function Ψ differentiates the allowed wave functions from the forbidden wave functions.
Moreover, the allowed wave functions and the forbidden wave functions given by the statistics of nature coincide with those of Schrodiger PDE.
The question arises: which is the most complete or contains the most information about the quantum system?
The quantum wave function (often represented as Ψ) and the differentiation between possible and impossible wave functions, particularly in connection with the Schrödinger partial differential equation (PDE). Breaking down your question into parts:
1. Statistical Matrix Definition of Quantum Wave Function (Ψ): In quantum mechanics, the wave function Ψ describes the state of a quantum system. It contains information about the probabilities of various outcomes when measurements are made on the system. The square of the absolute value of the wave function, |Ψ|^2, represents the probability density of finding a particle in a particular state.
2. Differentiating Possible and Impossible Wave Functions: In the context of quantum mechanics, certain wave functions may be considered "allowed" because they satisfy certain physical conditions and boundary conditions. For example, wave functions must be single-valued, continuous, and square-integrable, among other requirements. Wave functions that violate these conditions may be considered "forbidden" or "impossible."
3. Connection with Schrödinger Equation: The Schrödinger equation is a fundamental equation in quantum mechanics that describes how the wave function of a quantum system evolves over time. It's a partial differential equation that relates the energy of the system to its wave function.
The Schrödinger equation provides a mathematical framework to determine the allowed wave functions for a given quantum system. Solutions to the Schrödinger equation that satisfy the physical conditions and boundary conditions are considered possible wave functions, while those that don't are considered impossible or forbidden.
4. Completeness and Information Content: The question of which approach contains more information about a quantum system—whether it's the statistical matrix approach or the Schrödinger equation approach—is a nuanced one. Both approaches provide different perspectives and tools for understanding quantum systems.
The statistical matrix (or density matrix) approach is particularly useful when dealing with mixed states or systems that are not in pure states. It allows you to describe the probabilities of different outcomes without needing to explicitly solve the Schrödinger equation.
On the other hand, the Schrödinger equation is a fundamental equation that provides a direct link between the energy of a system and its wave function. Solving the Schrödinger equation yields the allowed wave functions of a system, and these wave functions contain information about the energy levels and behavior of the system.
Both the statistical matrix approach and the Schrödinger equation approach are important and complementary tools for understanding quantum systems. The Schrödinger equation gives insight into the allowed wave functions and their energy properties, while the statistical matrix approach provides information about probabilities and states of mixed systems. The choice of approach depends on the specific problem and the information you are seeking to extract from the quantum system.
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I need to know about the absorbance wave length in chlorophyll.
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Dear all,
I am trying to find a way to find dispersion curves of plates using Rayleigh-Lamb frequency equations. I used a repetitive procedure by sweeping through the frequencies and inside it increasing the phase velocity incrementally to find the roots of the equation.
In each frequency, there is some roots of phase velocity. As symmetric and asymmetric equations are already separated it is easy to separate data points of the two different waves. However, at the end of the process we have just (W frequency , Cp phase velocity) datapoints and after plotting the result we can see the behavior of the curves to manually define the mode number.
Main question: One way of clustering the data to different modes is to sweep through the data and define the first Cp as the mode zero, the second one as 1st mode and so on.
1. What if we had a crossing between curves?
2. I got some identical roots derived from both symmetric and asymmetric equations. How can one distinguish these datapoints correctly for the type of wave they belong?
Mohsen
The mode shapes between different modes are orthogonal, i.e., if the inner product of two mode shapes is close to 0, they are not the same mode. Conversely, if the inner product is not 0, they are the same mode. Errors may exist at positions where curves cross, which can be solved by reducing the computational interval.
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Two waves Y1 and Y2 are said to be coherent if their phase shift Phi 1 -Phi 2 is constant over time.
The question arises, can quantum entanglement be assumed to be a kind of forced wave coherence similar to that described by Einstein's laser, Amplification of Light by Stimulated Emission of Radiation?.
What is waving in the Schrödinger equation and why is it called the “wave” of the Schrödinger equation, especially when its phase is undefined?
It is well known that there is theoretical and experimental evidence for a causal relationship between the phase of the wave function and physical reality.
The Copenhagen interpretation of quantum mechanics, which only gives physical meaning to the magnitude of the wave function, cannot be considered complete on this basis.
* A new dynamic-statistical interpretation of quantum mechanics is needed [1,2].
Believe it or not, attaching a well-defined phase to the amplitude of the SE wave would no longer complicate it but on the contrary would make it more understandable and its solution more accessible.
However, we assume that defining a phase at the amplitude of SE can be done via two different approaches:
i-reform the Bohr/Copenhagen interpretation of the Schrödinger equation.
ii-Apply the complex transition matrix Q to find the statistical numerical solution of SE.
To be continued.
1-Ivan Georgiev Koprinkov, Phase Causation of the Wave Function or Can the Copenhagen Interpretation of Quantum Mechanics Be Considered Complete? Journal of Modern Physics Vol.7 No.4, February 2016.
2-I.Abbas,Numerical statistical resolution of the Schrödinger wave equation, Researchgate.
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Hi Folks~ I'm working with a student and one of the supervisors has suggested using FA on responses from wave 1, to select items to use in wave 2; is this a) ethical and
b) rigorous?
I'm thinking no on both counts:
It would be polite to ask permission of the original authors/publishers to break up their scales; 'stacking the deck' re. hypothesis testing, as the full/part scale will be chosen based on those scoring in the direction wanted (on average)
Or am I missing something (or more than one thing ~:-)
TIA
Thanks very kindly Nicco for your comprehensive and thoughtful response. By highlighting the extension of knowledge the process makes more sense to me now, in terms of ethics and rigor
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Since the time of N.Bohr, E.Schrdinger, W.Heisenberg and all the great scientists, physicists and mathematicians have called Schrödinger's equation the quantum wave equation.
If we agree on a definition of wave as oscillations in space and time as in emw (E and H oscillate), Sound wave (pressure and displacement oscillate), then the question arises:
Have physicists and mathematicians worked out the details of Schrödinger's equation in different situations up to the 10th digit, but forgot to specify what oscillates there?
The iron guards of the Bohr/Copenhagen interpretation defend to the last breath all issues of this interpretation, whether true or false.
Thanks to the opposition of the new generation of theoretical physicists and mathematicians, the old iron guards are only a small remnant of the era of MacArthism where the mastery of quantum mechanics dominated: Shut up and calculate.
Going back to SE with Bohr's interpretation, I guess these are the three most common mistakes while I'm sure most Researchgate contributors can find more:
1- Units and Dimensions
Bohr/Copenhagen interpretation of the wave function Ψ
defines the units and dimensions of Ψ differently depending on the number of dimensions of the receiving space.
i-For a spatial wave function of position 1D Ψ(x)
the normalization condition would be ∫Ψ∗(x)Ψ(x)dx=1
so Ψ has inverse square root units of length, which is m−1/2
ii-Similarly, for a three-dimensional position, the spatial wave function Ψ(x) has its own normalization condition such as:
∫Ψ∗(x)Ψ(x)d^3x=1
Ψ(x) has units of square root of inverse volume, which is m−3/2
Moreover, theoretical physics does not allow it, it is not acceptable.
Units and dimensions must be raised to zero or a whole whole power, but never to a fraction.
* If we compare this to the case of replacing SE with the statistical matrices Q and W, we find that the dimensions of W and Q are always the square root of the energy density per unit volume and the same is true for 1D, 2D and 3D.
The normalization condition is a pure summation condition and not an integration condition which is the sum of the multiplication.
.
2- The problem of distance and infinity
Distance is still defined in essentially the same way as in classical physics. In other words, spacetime is a flat Euclidean space with the usual Euclidean distance.
If we talk about the distance between two quantum particles, they must have a definite position in order to measure the distance between them. This requires them to be in proper positional states.
We assume that the SE interpretation with Bohr is limited to the study of the hydrogen-like atom where the total diameter distance is a few angstroms (Å) (1 A = 1E-10 m) and the effective electron radius is estimated at E -2 angstrom (Å).
The n=infinity mentioned in SE relates to the quantum number of infinite principle n which again corresponds to the diameter of the hydrogen atom by a few angeströms.
Obviously, the units and dimensions of the distance are not well defined in the SE interpretation.
** If we compare this to the case of replacing SE by the statistical matrices Q and W, we see that in the latter case the distance is well defined in 1D, 2D and 3D geometric spaces simply by ordering and arranging the nodes in these as we did for the actual transition matrix B.
3- Rigorous derivation
There is no rigorous or even serious derivation of SE with the Bohr/Copenhagen interpretation.
E. Schrödinger's solid derivation in 1927 proved other concepts in his equation and he himself considered the Bohr/Copenhagen interpretation an unpleasant joke. He expressed his feelings and thoughts through his well-known paradox. (Schrödinger's cat dead or alive).
*** If we compare this to the case of replacing SE with the numerical solution of the temporal chains of the statistical matrix Q, we see that in the latter case the derivation emerges from the well-proven statistical transition matrix B. Moreover, the results of the B-strings and Q-strings are
numerically validated.
To be continued.
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YES! THIS HAS BEEN SHOWN IN “PLANAR CRACKS IN UNIFORM MOTION UNDER MODE I AND II LOADINGS” (ANONGBA 2020).
Earlier works have suggested that crack speeds v could not exceed Rayleigh wave velocity, in the subsonic velocity regime (v< ct transverse sound wave velocity).
YES! THIS HAS BEEN SHOWN IN “PLANAR CRACKS IN UNIFORM MOTION UNDER MODE I AND II LOADINGS” (ANONGBA 2020).
THIS IS WITHIN THE THEORY OF LINEAR ELASTICITY!!!
In mode I loading and in the subsonic velocity regime (v < ct, the velocity of transverse sound wave), G (I) increases continuously with v from the value in the static case G(I)0 (v = 0) to a maximum G(I)max = 1.32 G(I)0 at v = v (e) =0.52ct; then, G (I) decreases rapidly to zero when v tends to ct. In agreement with experiments, the value v (e) corresponding to the maximum of the crack extension force is identified to the terminal tensile crack velocity, observed in the fracture of brittle materials. No reference is made to the Rayleigh wave velocity cR. In the transonic speed regime (ct < v < cl), the crack characteristic functions are identical in form with those of the subsonic regime. However, for v < ct√2, we show that the faces of the crack, separated under load before the extension of the crack, close under motion; this indicates that the crack movement is hindered. for v > ct√2, the motion of the crack is possible. In mode II loading and in the subsonic regime (v < ct), G (II) increases continuously with v (when v < cR) from the value in the static case G(II)0(v = 0); when v approaches cR, G (II) increases very rapidly. Above cR (cR < v < ct), the relative displacement of the faces of the crack, formed under load before crack motion, closes in motion; this indicates that crack motion is impeded. The velocity of uniformly moving cracks is limited by the Rayleigh wave velocity. In the intermediate speed regime (ct < v < cl), the crack characteristic functions are similar in form to those below cR. The mouvement of the crack is possible.
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Hi, there
I need urgent help please, I am working on tri band antenna project, I started to simulate some papers design in HFSS but I can’t get the same result as in the paper, it is not small differences
1- Higher or lower resonances (500 Mhz) maybe
2- Different S11 levels
3- Different S11 curve specially for higher frequency.
Here I have attached the paper, my HFSS design, If any one could help to get the same results as in the paper, as the paper also measured the physical antenna, so at least I should get at least same simulation results, I tried to change a lot of things, excitation size, solution frequency ..etc
I am using HFSS 2021 R1…
I want to get same results using wave port and lumped port if possible.
One more thing, I have added small fixer at the end to the original design in order to connect the lumped port …..is there any optimum value for the wave port length..!!!!!!!!
It will be very help full if you could suggest how to excite the structure by both wave port and lumped port,,,
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I am developing a 2D photonic crystal resonator and would like help from colleagues to configure the propagation of electromagnetic waves in the time domain using the wave optics module. Researching devices based on 2D photonic crystals simulated in comsol on the internet, I realized that there are few tutorials using this software. Can anyone tell me why?
I'm working with linear optics and I want to study the transmission spectrum at the output of the four ports of the projected photonic device.
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I am designing a circular wave guide with TE11 mode and frequency of about 1.5 GHz. does anyone know how to calculate the radius of the waveguide?
A search for cutoff of circular waveguide found this
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If I vary the 'phi' angle, the modes changes from TE to TM. But it was supposed to change the azimuthal angle.
Use floquet boundary condition with unit cell in perpendicular directions, You will able to change phi.
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Hi,
i'm looking to expose my cells culture to ultrasounds.
I need a way to expose the cells to 0.5MHz, 1Khz PRF with an intensity of 0.35-0.5MPa.
Any suggestion?
I get my electronic components from https://www.digikey.com/
BTW Ultra sound can due to micro bubble formation and bubble collapse/impolsion cause lipid peroxidation and ROS formation. Therefore, I wouldn't use too much power, or you may have a lot of other effects to control for.
The detection of oxidation in liposome preparations
October 1970 Biochimica et Biophysica Acta 210(3):486-9
DOI: 10.1016/0005-2760(70)90046-9
Good luck.
Phil
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For my master's study, I need the parameters of an offshore wind turbine built with a jacket type foundation. I need a study in which the basic dimensions of the jacket type are known and the field characteristics (wind, wave load, etc.) are known. Do you have such a work or an article you can send?
Did you find any relevant sources? I am working on something similar and am unable to actually find that information!
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In quantum mechanics, the Schrödinger equation calculated wavefunctions with a wave structure over space and changing over time. The Copenhagen interpretation, namely Born‘s interpretation states that the square modulus of the wavefunction represents the probability density function of the particle over space and time. Thus, there will be a distribution of the particle over space because we know particles are moving in the system and may favor some locations.
This is a very confusing explanation that several founders of Quantum Mechanics including Schrödinger himself, Einstein, and de Broglie have formally expressed disagreement.
I have been teaching undergraduate quantum chemistry for several years and also felt difficult to explain the probability density function why there are nodes in the solution where particles will never show up with no particular reason to avoid those places. I have been trying to come up with a different explanation of the wavefunctions with a preprint firstly posted on ChemRxiv in 4/2021. Since then I have been thinking on it and working on revisions while teaching quantum again in the past few years.
DOI: 10.26434/chemrxiv-2022-xn4t8-v17
It reaches a very surprising conclusion that the wavefunction has nothing to do with statistics as Schrödinger himself has argued many times including the famous Schrödinger’s cat thought experiment.
I recently posted the preprint in RG. Please take a read and comments are welcome. I will be teaching quantum again next semester now I have even more difficulties since I have lost beliefs on the classical interpretation.
Quantum as the name implies, describes an observation we have made to the microscopic systems you have described that energy is discrete rather than continuous, which is a typical phenomenon we see in resonated wave systems at the macroscopic scale. Other than this, there should be no difference from the classical mechanics you and I have learned to describe the observations we have measured or others have measured and we trust their measurements.
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Gravitational waves that are detected by the current detectors are of long wavelengths and are hence low on energy, but during the initial phase of the universe high energetic phenomena like cosmic strings may have given rise to GWs with high energy. So, what could have been the upper bound for the energy of this waves during that time.
GW are produced typically under close rotation of two very heavy masses, like two black holes.
Never heard yet about origin from Cosmic Rays. This sound unlikely to me.(cannot imagine a mechanism).
Very high energy cosmic rays are thought to be a product of decay of some heavy particle.
When energetic cosmic rays come, all that happens are important particle showers, muons that in turn
decay into other particles.
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From WIMP to axionic dark matter, their wave function has similar contribution on building the ocean of waves in the universe. Axions being pretty smaller than WIMP, ~10-6 μeV/c2 in mass, they have de Broglie wavelength very larger. Overlapping of one wave into another creates the complex phenomena which shapes the large structure of universe and distribution of matters into it.
So how does this scale of de Broglie wave of different candidates of dark matter; (WIMPs , axions, fuzzy), affects the behaviour and distribution in the universe? Simply how does the size of dark matter candidates affects the structure and distribution in universe?
Let’s continue, though firstly note, that all really fundamental phenomena/notions, first of all in this case “Matter”, “Consciousness”, “Space”, “Time”, “Energy”, “Information”, and so everything in Matter – particles, fields, fundamental Nature forces, etc., are fundamentally completely transcendent/uncertain/irrational in mainstream philosophy and sciences, including in mainstream physics,
- while all these phenomena/notions can be, and are, rigorously scientifically defined only in framework of the Shevchenko-Tokarevsky 2007 “The Information as Absolute” conception, recent version of the basic paper see
- where it is rigorously proven that there exist nothing besides some informational patterns/systems of the patterns, which are elements in the absolutely fundamental and absolutely infinite “Information” Set, including Matter absolutely for sure is some informational system;
- and more concretely in physics in the SS&VT informational physical model, which is based on the conception, two main papers are
and
In the conception the outstanding fundamental von Weizsäcker and Fredkin-Toffoli hypotheses that Matter in ultimate base is based on binary reversible logics, which were some transcendent assumptions, become be completely legitimate and rational, so the SS&VT model is based on this proposition,
- correspondingly in the model the ultimate base of Matter is the Matter’s aether – primary elementary logical structures – (at least) [5]4D binary reversible fundamental logical elements [FLE], which compose the corresponding (at least) [5]4D dense lattice, which is placed in the corresponding Matter’s fundamentally absolute, fundamentally flat, and fundamentally “Cartesian”, (at least) [5]4D spacetime with metrics (at least) (cτ,X,Y,Z,ct),
- while everything in Matter is/are some specific disturbances in the lattice, which, including disturbances “particles”, always constantly move in the lattice with 4D velocities that have identical absolute values be equal the speed of light, c, since this speed is determined by the FLE’s universal parameters – “FLE size”, and “FLE flip time” which are equal to the Planck length and Planck time, c= Planck length /Planck time.
Particles are some cyclic close-loop algorithms which constantly run as sequential the lattice’s “FLE by FLE” flipping, when so the “FLE flip point” moves along some 4D “helix”, at that:
- if a having rest mass particle is at rest in the absolute 3D space, and so moves with speed of light only along the -axis, its helix has radius λ=ћ/mc, i.e. is the Compton length of the particle, the particle has 4D momentum P0=m0c[“bold” means 4D vector] and energy E=Pc=m0c2, m0 is the rest mass. If the particle is impacted by a 3D space directed momentum p, 4D momentum P=P0+p=γm0c,
- at that the initial 4D helix becomes be some composition of two helixes – initial one and that has radius λB=ћ/p, which is observed as a de Brogile wave that has the length be equal λB.
Correspondingly that
“….All the particles in question are point-like,….”
- really isn’t completely correct, particles only interact as “points” that have “sizes” ~ Planck length, however this “particle-point”, at least at interactions, randomly can be in any point in 4D [and 3D] space quite non-point-like volume that has size ~λB, if the particle’s speed is well lesser than c,
– what is observed in QM as the “wave-particle duality”.
SS posts in
- are relevant to this thread question.
Cheers
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i have generated a triangle wave in matlab and now i want to use that wave as input to my simulink model
Simulink provides several ways to import data from MATLAB or other sources. One way is to use the "From Workspace" block in Simulink.
Here are the steps you can follow:
1. In your MATLAB code, save the graph data as a variable in the workspace. For example, if your graph data is stored in a variable named "myGraphData", you can save it to a .mat file using the following command: save ('myGraphData.mat', 'myGraphData');
2. In Simulink, add a "From Workspace" block to your model. This block allows you to import data from the MATLAB workspace.
3. Double-click on the "From Workspace" block to open its dialog box. In the "Data" field, enter the name of the variable that contains your graph data (in this case, "myGraphData").
4. Set the "Sample time" parameter to the appropriate value depending on how often you want the data to be sampled.
5. Connect the output of the "From Workspace" block to your logic.
6. Run the simulation.
Your logic should now receive the graph data as input from the "From Workspace" block.
You can use the "From Workspace" block in Simulink to input your generated triangle wave from MATLAB. Here are the steps you can follow:
1. Generate your triangle wave in MATLAB and save it as a variable in the workspace. For example, if your triangle wave is saved as a variable named "triangleWave", you can save it to a .mat file using the following command: save('triangle_wave.mat', 'triangleWave');
3. Double-click on the "From Workspace" block to open its parameters dialog box.
4. In the "Data" field, enter the name of the variable that contains your triangle wave (in this case, "triangleWave").
5. Set the "Sample time" parameter to the appropriate value depending on how often you want the data to be sampled.
6. Connect the output of the "From Workspace" block to the input of your simulink model.
7. Run the simulation.
Your triangle wave should now be used as input to your Simulink model. Let me know if you have any further questions or if there's anything else I can help you with!
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In cyclic voltammetry, I ran a reduction blank from 0 to -1.6 V, in tetrabutylammonium perchlorate (TBAP) and dichloromethane, but the CV diagram shows a small wave at around -1.2 V, and I don't know if it is normal or abnormal, and if it is abnormal, what is the problem? The picture is below.
The working electrode I used is Pt electrode,and it has plastic resin around it, I also change a new working electrode to see if it is the problem, but the result is still the same.
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I am working on a paper on smoking and depression in a sample of approximately n=2.000 subjects, and for that, I use longitudinal data (5 waves, 2 years between each wave). For a part of the paper, I want to analyse determinants of smoking in those with depression (both depression and smoking are time-varying variables). The most simple solution would be to do a cross-sectional analysis (for example with the baseline data), but I was wondering whether I could also use all data, and perform a mixed models analysis but without TIME. I feel that the additional value of doing that would be to 1. have more data points (5x2.000=10.000 instead of 2.000); and 2. not only to make a between-person interpretation but also a within-person interpretation. However, I have never read a paper, answering this type of questions (determinants of condition x in disease y) doing a mixed models analysis. Therefore my questions is: am i right and should I do it this way, or do I miss a critical argument not to do so?
There may be some additional value of using mixed models for this type of analytic question, depending on the research objectives and the characteristics of the data. Mixed models are a flexible and powerful tool for analyzing longitudinal data, as they can account for the correlation among repeated measurements within subjects, handle missing data under certain assumptions, and model both fixed and random effects of covariates. Mixed models can also provide both conditional and marginal interpretations of the effects of interest, depending on the specification of the model.
However, mixed models are not without limitations or challenges. They require careful selection and justification of the covariance structure, the distributional assumptions, and the random effects. They may also suffer from computational difficulties or convergence issues when fitting complex models to large datasets. Moreover, mixed models may not be appropriate or necessary for some research questions or data scenarios. For example, if the main interest is in testing for time trends or interactions with time, then a simpler approach such as a generalized estimating equation (GEE) may suffice. Alternatively, if the main interest is in modeling the transition probabilities or the dependence structure of the outcomes over time, then a different approach such as a Markov model or a copula model may be more suitable.
Therefore, the choice of using mixed models for this type of analytic question should be based on a clear understanding of the research question, the data structure, and the advantages and disadvantages of different methods. A comparison of different methods using simulation studies or sensitivity analyses may also help to evaluate the robustness and validity of the results.
I cannot comment on your concrete model without knowing more details about it, such as the outcome variable, the predictor variables, the number and spacing of the time points, the distribution and correlation of the data, and the research hypotheses. However, based on the general description of your question, I can suggest some possible steps to consider when applying mixed models to your data:
- Explore and visualize your data to check for outliers, missing values, trends, patterns, and assumptions.
- Decide whether you want to use a linear mixed model or a generalized linear mixed model, depending on the type and distribution of your outcome variable.
- Choose an appropriate covariance structure for the random effects and the residuals, such as compound symmetry, autoregressive, or unstructured. You can use information criteria such as AIC or BIC to compare different structures and select the best one.
- Specify the fixed effects and the random effects in your model. You can include both time-invariant and time-varying covariates as fixed effects. You can also include random intercepts and/or random slopes for subjects or other grouping factors. You can use likelihood ratio tests or Wald tests to test for significance of the fixed effects and the random effects.
- Fit your model using a software such as R or SPSS. Check for convergence, diagnostics, and model fit. You can use plots or tests to assess normality, homoscedasticity, linearity, and independence of the residuals. You can also use cross-validation or bootstrap methods to evaluate the predictive performance of your model.
- Interpret your model results in terms of conditional or marginal effects. You can use confidence intervals or hypothesis tests to estimate and compare the effects of different covariates on the outcome variable. You can also use plots or tables to visualize the effects over time or across groups.
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China has decided to step up its exploration of the Earth's interior by drilling a 10,000-meter-deep hole in the Earth's crust.
I believe that China needs my knowledge and forecasts to take measures to protect equipment in the event of the passage of the Kozyrev-Yagodin low-frequency wave. With its (wave) passage, it can vibrate and destroy the mine. It is described in my articles.
In this case, China really needs my methodology and system for accurate short-term earthquake prediction.
I am writing to you, my esteemed Chinese colleagues.
In fact, the theory, the stages of development of the Genesis of earthquakes, the acting forces, and the physics of the process have already been disclosed by me and described in articles since 2007. Based on the theory, practical tests of the earthquake forecast in real conditions were carried out under the supervision of Prof. Strashimir Mavrodiev, prof. A.V. Nikolaev - Chairman of the Russian Expert Council, confirmed by the meeting of the REC 2015 and the conclusion of Prof. E.A. Rogozhin in 2016.
The Scientific and Technical Council of the VNII GOChS of the Ministry of Emergency Situations of the Russian Federation adopted a report on the Genesis of earthquakes and the recommended forecast complex.
Look at the 2017 meeting of the Israeli Knesset Commission, - geophysicists have recognized that the methods of reporting that an earthquake has begun lead to great casualties. My methodology has been verified by the Chief Scientist of the Israeli Ministry of Defense and accepted for transmission to interested ministries. Those who need to save the lives of their citizens can contact me and I am ready to transfer the methodology.
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How waves carry energy but not matter and how does energy move during changes of matter?
Dear Rk Naresh, waves are a means by which energy is transmitted through a medium or space, but they do not transfer matter. When a wave propagates, it carries energy from one location to another without physically displacing the particles of the medium. This is known as the transfer of energy without the transfer of matter.
During changes of matter, energy transfer occurs through the exchange of kinetic energy between particles. Energy is absorbed or released as the particles' motions change due to changes in temperature or other external factors. It's important to note that energy transfer is not limited to phase changes but also applies to other processes like chemical reactions, where the arrangement of atoms and molecules is altered while energy is exchanged.
waves transmit energy without transferring matter, and during changes of matter, energy is transferred through the exchange of kinetic energy between particles.
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There are many articles about wavelengths of infra red rays used. There are many articles about wavelengths of radio waves used. There are many websites about spectrum of electromagnetic waves. But, I could not find any article which mentions about maximum possible wavelengths of light rays (including infra red rays) constructed or used, and I could not find any article which mentions about minimum possible wavelengths of radio waves (including micro wave) constructed or used. I do not need theoritical articles. I do not need theoritical possibilities. More specifically, I like to know whether any light ray with wavelength 1.5 mm (>1.1 mm) has been constructed, and to know whether any radio wave wavelength 1.5 mm (<1.9 mm) has been constructed.
Thanks professor for your references. The maximum wavelength for IR rays that I could find from the references is 25000 nm=0.025 mm. So, I shall wait. Thanks again.
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Scientists, and many other people, have pondered this question. This article - (PDF) Graviton-Photon Interaction and Mass Generation: A Vector-Tensor-Scalar Geometry Approach (researchgate.net) - speaks of retarded and advanced gravitational and electromagnetic waves which respectively travel forwards and back in time, cancelling each other and entangling particles throughout the universe (the physicist Richard Feynman loved advanced waves). It also says particles are thus united into one place in space-time and the idea of their existing in two spots, or times, at once is an outlook resulting from perception of all things and events as distinct and separate. As page 12 of the article puts it, “An alternative interpretation might see these particles unified into a singular entity by the action of advanced and retarded waves, leading to a concept we might call “unipositionality”, drawing from the Latin ’unus’ meaning one.”
If we accept the articles’ propositions, all of space-time plus its contents would be a single entity – a step towards a Unified Field Theory, a Theory of Everything or Quantum Gravity - and the equation 1+1=2 (and presumably every other equation, no matter how complex) appears at first glance to be obviously impossible. Yet those same equations do describe the world and universe remarkably accurately. Is there another explanation besides the apparent one – someday there will be a human civilization that can build their mathematics into the creation, structure, and functioning of life and the cosmos. Emotion may well declare this an absurdity and we might retreat to things like quantum fluctuation or spontaneous creation from nothing. Logically – using Einstein’s nonlinear, curved time added to limitless advance of human potential through the eons – the absurdity is plausible.
Even though mathematics is a universal language, before it can do that, there must be a mastery of abstraction, logico-mathematical, to certain degree cognitive components, etc. within an observer to qualify such good qualities
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What is the similarity between matter and energy and relationship between matter and energy in waves?
The matter is anything in our universe that occupies space and has mass. The mass is the measurement of the matter. On the other hand, energy is defined as the ability to do work or the ability to transfer heat. Examples of matter and energy are book and light energy respectively. Food webs can be used to reveal different patterns of energy transfer in terrestrial and aquatic ecosystems. Patterns of energy flow through different ecosystems may differ markedly in terrestrial and aquatic ecosystems. Food webs can be used to reveal these differences. Normally, food webs consist of a number of food chains meshed together. Each food chain is a descriptive diagram including a series of arrows, each pointing from one species to another, representing the flow of food energy from one feeding group of organisms to another. The wave function for a material particle is often called a matter wave. The relationship between momentum and wavelength for matter waves is given by p = h/λ, and the relationship energy and frequency is E = hf. So energy and matter is really the same thing. Completely interchangeable and finally, although energy and mass are related through special relativity, mass and space are related through general relativity.
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Deep learning involves arriving at concrete memory and recall ability outcomes, which were not possible in surface learning
i.e. one who understands quantum mechanics knows by memory that in simple potential cases the wavefuntion is plane wave and in free particle sinusiodal or that operators with that commute have same eigenvalues and similar probabilities.
But these are not outcomes of surface knowledge and only reached at an advanced level of understanding where memorization is EASY
Thus memory's role in learning theories is unjustifiably minimized
Memory and deep learning are related but distinct concepts. Memory refers to the ability to store and retrieve information, while deep learning is a subfield of machine learning focused on training artificial neural networks. Deep learning can enhance memory processes by providing meaningful and context-rich learning experiences, but it does not directly mimic human memory. Deep learning algorithms excel in pattern recognition and prediction, which can aid tasks related to memory, but memory itself involves encoding, storage, and retrieval processes.
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We know that at minimum of a group velocity curve, we get Airy phase with large amplitude of surface waves. My question is: Does the amplitude depends on the sharpness of minimum i.e. on |dU/dT| around the group velocity minimum? Here I have used U as group velocity and T is period of surface wave.
Hello, thank you for your question. Airy phase is a phenomenon that occurs when the group velocity of seismic surface waves reaches a minimum at a certain period. The Airy phase has a large amplitude and a long duration because it is a stationary phase that accumulates energy from nearby periods.
The amplitude of Airy phase does depend on the sharpness of the group velocity minimum, as well as on other factors such as the source spectrum, the attenuation, and the noise level. [1] The sharper the minimum, the more energy is concentrated in the Airy phase and the higher its amplitude. However, if the minimum is too sharp, it may also cause interference effects that reduce the amplitude of the Airy phase [1].
The sharpness of the group velocity minimum is related to the gradient of the group velocity curve around the minimum. The gradient can be expressed as |dU/dT|, where U is the group velocity and T is the period. The larger |dU/dT|, the sharper the minimum and the higher the amplitude of Airy phase.
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Does group velocity of a wave packet in a dispersion medium depend upon the width of the wave packet?
I think it can do, because group velocity can depend on frequency, so a long pulse containing low frequencies may travel at a slower speed than a short pulse containing high frequencies. this woukd be scaling the frequency of a signal, which would move it along the dispersion curve, which could change the group velocity. I don't think reducing the bandwidth of a pulse at the same frequency, to make it longer, would change its speed, though.
It s possible this might happen in a non-linear medium.
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Many theoretical physicists mention the cosmic wave function, but the issue is that according to the laws of quantum mechanics, who is the observer of this wave function to collapse it into a universal special state? This type of view is close to the view that exists regarding the interaction of human consciousness with the world and what it sees. Is the mechanism of human consciousness, in its most fundamental form, based on the laws of fundamental particles that can interact with the world around it? Are there more hidden structures than what theoretical physicists see, causing human consciousness to interact with the world around them? Could these hidden structures be the same hidden world as predicted in the holographic theory of the world?
ِDear André Michaud;
You may send this previous dialogue again, I think the sentences are a little messed up.
thank you
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Energy of a photon is given by the expression, E=hf. Is this the frequency of most prominent wave? Due to the localized nature of photon, photon consist of  all possible wave length from zero to infinity and consequently all frequency from zero to infinity.
Speed of light(c) = wavelength(𝜆) * frequency (f). if f =0, then c = 0. No light ... it's dark. Therefore, f must be between zero and infinity.
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waves passing through rigid vegetation
The lower curve does not contain any noticeable frequencies, so it results in a flat spectrum. The upper curve contains a superimposed damped oscillation that appears as an additional peak in the FFT. Both components can be separated by high-pass / low-pass or notch filters.
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Electron is an experimentally verified yet highly speculated and theory of structure of matter co-dependent construct and entity. Fouble slit results further stress this abiguity bevause its has a strange physical entity type"property duality".
Dirac proposed the medium if the world as an alternative to sub atomic structure, an ether like entity containing known subatomic particles but as a medium not as a repeated structure.
Double slit experiments are dubious because they accept two equal explanations about the nature of electron, or better validate its wave nature while also respecting its particle nature in an aproximation.
So electron must be revisited. Maybe relying on Diracs conception for its part of a medium like entity may shed light on double slit paradoxes.
How would this be, there are no current sugggestions because the rival subatomic repeated structure theory is uncontested.
Not specifically electrons. The double slit or similar experiment works with many other particles.
Its a generic quantum property of elementary particles.
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Не так давно умерли Председатель Российского экспертного совета:
проф. А.В. Николаев и проф.Е.А. Рогожин, бывший и Председателем Экспертного совета России и Зам. директором РАН и председателем комиссий конференций...
В КНИГЕ ПАМЯТИ те, кто с ними работал пишут об уважении к ним, о том, что они были лидерами, экспертами. Честными, строгими.
Так почему сразу после их смерти их работу сваливают "в грязь", пытаются заткнуть автора?
Все знают, что научное заключение Генезиса землетрясений, данное РЭС положительное. Нет ни одной проработки этапов и действующих сил, чтоб все было логично и подтверждалось и теорией (скорость волны Козырева-Ягодина рассчитывается теоретически из движений Земли, Луны, Солнца) и скорость волны дает время прохода волны от станции до места, где произойдет землетрясение.
РУБЕН ЭДУАРДОВИЧ ТАТЕВОСЯН - Заместитель директора ИФЗ РАН непрерывно в своих выступлениях на публику повторяет, что "не существует точного классического краткосрочного прогноза землетрясений". Вы читали протокол РЭС по экспертизе работы Александра Ягодина (Председатель проф. А.В. Николаев).
Вы читали заключение по результатам испытаний !!!! Вы понимаете, что такое испытания и что означает заключение РЭС? Или Вы со смертью последних честных ученых уничтожили и то, что было "сделано до вас"?
ВАМ САМИМ НЕ СТЫДНО ЗА ИНСТИТУТ, ЗА СТРАНУ?
Вы заявляете ложь россиянам. Вы готовы убить людей в землетрясении, но скрыть то, что сделал А.Ягодин, поддержал Страшимир Мавродиев, проверили и подтвердили Николаев и Рогожин.
Вы эту ложь пишете и Президенту России, пользуясь тем, что Генеральный прокурор занят другими проблемами?
Интересно, все так лгут в РАН? Ни один человек не заявил правду, которую приняли на заседании РЭС 2015 года?
Not so long ago, the Chairman of the Russian Expert Council died:
prof. A.V. Nikolaev and prof.E.A. Rogozhin, former Chairman of the Expert Council of Russia and Deputy. director of the Russian Academy of Sciences and chairman of the conference committees ...
In the BOOK OF MEMORY, those who worked with them write about respect for them, that they were leaders, experts. Honest, strict.
So why, immediately after their death, their work is dumped "in the mud", trying to shut up the author?
Everyone knows that the scientific conclusion of the Genesis of earthquakes given by the RES is positive. There is not a single study of the stages and acting forces, so that everything is logical and confirmed by theory (the speed of the Kozyrev-Yagodin wave is calculated theoretically from the movements of the Earth, Moon, Sun) and the wave speed gives the time it takes the wave to travel from the station to the place where an earthquake occurs.
RUBEN EDUARDOVICH TATEVOSYAN - The Deputy Director of IPE RAS constantly repeats in his speeches to the public that "there is no accurate classical short-term earthquake forecast". You have read the protocol of the RES on the examination of the work of Alexander Yagodin (Chairman Prof. A.V. Nikolaev).
Have you read the conclusion of the test results !!!! Do you understand what tests are and what the conclusion of the RES means? Or, with the death of the last honest scientists, did you destroy what was "done before you"?
ARE YOU NOT SHAMED FOR THE INSTITUTE, FOR THE COUNTRY?
You are telling lies to the Russians. You are ready to kill people in an earthquake, but to hide what A. Yagodin did, supported by Strashimir Mavrodiyev, checked and confirmed by Nikolaev and Rogozhin.
Are you writing these lies to the President of Russia, taking advantage of the fact that the Prosecutor General is busy with other problems?
I wonder if everyone lies like that in the RAS? Not a single person stated the truth that was accepted at the REC meeting in 2015?
Dear Alexandr,
Why don't you contact the geophysicists of SPEC.
Sincerely, László
Уважаемый Александр!
Почему бы вам не обратиться к геофизикам SPEC.
Искренне, Ласло
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I believe that if we accept the fact that the WQPD [Wigner QuasiProbabilityDistribution] is in fact a regular probability distribution (so there is nothing "quasi" about it) despite not being globally non-negative, Bell's analysis falls apart (probabilities are not non-negative & measurements at distant points of entangled [correlated] particles are not independent) and we can reduce the results of the Aspect, &c., experiments to mere correlation, Bertlmann's socks. For instance, if the wave function is d(x2-x1) (d = Dirac Delta Function), the wave function of the original 1935 EPR thought experiment, the WQPD is d(x2-x1)d(p1+p2), which cannot be reduced to form p(x1,p1)p(x2,p2)--i.e., there is correlation/Bertlmann's socks). Naturally, one has to use the 2-particle WQPD. I believe that a similar circumstance would occur if one calculated the WQPD for spin/position as well as momentum/position. Whaddya think? As for negative probabilities: we simply have to redefine a "probability" as a tool for calculating mean values rather than the classical definition (# times something happened/# runs of experiment). Stuart Boehmer
Has anyone noticed that QM indistinguishable particles are just entangled distinguishable particles?
In that case, if I’m right that entanglement = correlation (I am 😊 ), we could study classical indistinguishable particles as a special case of correlation between them. We also could study classical EPR & Bell experiments & settle the matter (of whether entanglement = Bertlmann’s socks/correlation) once and for all……………
Namaste
Stuart Boehmer
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What happens if a wave beam is introduced into a waveguide line with some mis-alignment (Offset and or Tilt)? Does the wave beam behave like an optical ray and continue to carry the misalignment as it propagates through the waveguide line and emerges with the misalignment at the end of the line? Or as the waveguide is a guided structure with a mode pattern the initial misalignments have no effect at the other end of the waveguide, though there may be some extra losses at the entrance due to misalignment? I m basically interested for beam propagation inside corrugated waveguide with some offset/tilt
Energy can only travel in the waveguide in the permitted waveguide modes. If there is only one mode permitted, the energy must travel in that mode, or not at all. If the incident energy does not match that mode in angle or distribution, then some will be reflected. There will be modes that can be added together to match the incident field, but they will be non-propagating (evanescent) and result in energy being stored near the generation point. They look like series and/or parallel inductance and/or capacitance. This reactance corresponds to the mismatch in impedance that results in the reflection. If many propagating modes are possible, then the energy is spread among the modes that can be combined to give the closest approximation to the incident wave. Look up mode conversion in waveguides to see how this can be calculated.
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Quantum physics is the study of matter and energy at its most fundamental level. A central tenet of quantum physics is that energy comes in indivisible packets called quanta. Quanta behave very differently to macroscopic matter: particles can behave like waves, and waves behave as though they are particles.
source: Quantum physics - Latest research and news | Nature
The field of Quantum Information Science (QIS) is a rapidly growing field, with an expanding number of potential applications that explore the capabilities of currently available noisy quantum devices and promise to eventually solve problems beyond anything that classical systems can accomplish. In the past few years, this expectation for transformational applications has translated to a lot of attention, both from the media (reaching the scientific community and the general public) and the government funding agencies and technology industry. The significant advances have been made in developing new techniques and algorithms and advancing quantum technologies, resulting in applications that are addressing real problems (albeit simplified, in most cases, or very specialized).
Developing portable quantum computers will require advances in miniaturizing and integrating quantum hardware, improving qubit coherence times, and increasing the efficiency of quantum error correction techniques. Progress in these areas will bring us closer to realizing the potential of practical, portable quantum computers.
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What is the future of green energy and its potential for meeting our energy needs?
What do you think? It will be solar, wind or wave?
You can take a look at this published article and the exciting prospects of Solar Energy deployement due to its abundancy, reliability, and low cost of installation. It has been motivated as an alternate source of energy in oil consuming regions such as the GCC with policies and regulations implemented.
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The decisive answer is left to the experts in quantum mechanics, not me.
But what's really annoying is that for every fundamental quantity, even the Psi wave function itself, you get 3 or more different interpretations where none of them are complete.
People often perceive quantum mechanics as an ad hoc collection of ideas because it is a highly complex and abstract field that challenges our everyday intuitions. It is true that the field has multiple interpretations, and this can lead to confusion and the perception that physicists and mathematicians are still "guessing" about its principles. However, this is not a reflection of a lack of understanding, but rather an indication of the rich and deep nature of the subject.
There are several reasons why people might have this perception:
Counterintuitive concepts: Quantum mechanics deals with phenomena at the atomic and subatomic levels, where the behavior of particles can be very different from what we observe in the macroscopic world. Concepts like wave-particle duality, superposition, and entanglement can be hard to grasp and often seem bizarre.
Multiple interpretations: As you mentioned, there are several interpretations of quantum mechanics, such as the Copenhagen interpretation, the Many-Worlds interpretation, and the de Broglie-Bohm interpretation, among others. Each offers a different perspective on the nature of reality and the behavior of quantum systems, but none are universally accepted as the "correct" interpretation. This can lead to the impression that the field is uncertain and speculative.
Mathematical complexity: Quantum mechanics is built on sophisticated mathematical tools and models, which can be challenging even for those with a strong background in mathematics. This complexity can make it difficult for non-experts to appreciate the rigor and coherence of the field.
Ongoing research: Despite its remarkable successes, quantum mechanics is not yet a complete theory. Researchers continue to investigate open questions and explore new ideas to better understand the quantum realm. This ongoing research can give the impression that the field is still a work in progress.
So, while quantum mechanics is indeed a complex and multifaceted field with multiple interpretations, it is not a random ad hoc collection of ideas. Rather, it is a well-established and highly successful branch of physics that has provided us with profound insights into the fundamental nature of the universe. Its ongoing development and open questions are a testament to the richness and depth of the subject, as well as the dedication of the scientific community in seeking a deeper understanding of the quantum world.
Regards,
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That the relevant experimental results are rigorous is not in question here, but the explanations imagined by physicists since the first person wondered about the Moon worry me! I do not care whether Albert Einstein or Neils Bohr was right on the EPR issue: physics is about correcting limitations of magnificent efforts in the past. I just want to understand the nature of Nature better than I do now. My questions are efforts to explore; they are not challenges.
To me, entanglement in non-locality means “here and there go we” and the verbiage that treats separated aspects of one self is misleading. That is, “we” is one self (persona), so the phrase is actually “here and there go I.” (“My skin is not my surface.” lfh.) The aspects of “we” are “form on ground,” the rest frame of the electromagnetic field, at least until they are instantiated by interaction. How does that “ground” read its lines in this drama.
That neither of the “separate particles” that are separating becomes its true self until it becomes defined by an interaction is measured. How do their waveforms separate so they may be considered “unreal” individuals instead of two “unreal” ripples on a common wave. When does the second particle become “real?” Setting aside a hidden variable like a pilot wave, how far in advance of the pairs do their waveforms extend, and how broadly? How is entanglement effected in nature as an actual phenomenon?
An internal communication sufficient to effect the entanglement result appears to be unknown. My observations and questions are just more verbiage without that communication. However, were Paul Dirac’s “sea of negative” energy valid, or were the ideas in the cosmology of inflation valid, then the communication could be effected by “the ground,” that sea of negative energy with “backward in time” antiparticles or ~instantaneous negative gravity activity. It’s a thought. . . .
The problem is: “it is measured that . . .” and “it is not known that . . .” and here we are again! Of course these questions cannot be answered – yet. If you give it a shot, your effort will be appreciated and undoubtedly interesting!
Leonard Hall Hi Len. I just wanted to pick up on one point that I think is really significant in these models. You mentioned the idea of a source and sink in the field.
It is the word “field” that is the concern. There has been a tendency to talk about fields as real physical entities which are fundamental in nature. The standard model does this a lot.
This is an important point so I am going to give it some time. Since around 1920 there has been a tendency to think of light as an excitation of the magnetic field and therefore give the electromagnetic field a real physical existence. You could describe it as a quantum field rather than a classical field.
Now you can see why in the opening slide of the unification of physics video I talk about the LIGO experiment. The observation results of a distant neutron star merger show that gravitational waves and electromagnetic waves travel at exactly the same speed even over expanding space.
This must mean that electromagnetic waves are waves in the medium of space not waves in the electromagnetic field.
This point is crucial but it means that the only fundamental thing is the medium of space and all fields are classical meaning that they have an underlying cause.
Richard
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As we know EM waves are widely used in our life. One of the common use of these waves is in the kitchen and specially microwave.is it really Carcinogenic?
I just realized that I answered the wrong question. I thought about the harm from microwave ovens to the human body due to microwave radiation. However, the question was about damage from food cooked in a microwave oven. I think that microwave oven does not provide any harm to food and, consequently, to the human body. There may be very rare cases when food has very little water only in some parts of it. In this case, may be possible burning of these small parts. It will create burned protein and these small pieces may be cancerogenic.
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..
Do you mean that if the number of cycles per second changes, does the number of cycles a metre have to change?
If that is what you mean the answer is yes, if the velocity stays the same. The wave has to travel one wavelength in the time it takes for one cycle, the period. This means that the velocity is wavelength/period = cycles per second/cycles per metre.
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Is there any nuclear reaction code available to calculate transfer reaction cross-sections using adiabatic distorted wave born approximation (ADWBA) ?
Hi,
Thank you very much for the reply and suggestions. The code NLAT is suitable for mass number less than or equal to 2. I am looking for a code to be used for masses greater than 2.
Thank You
With Best Regards
Vishal
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How can the waves emitted from the human body be sensed?
Agnieszka Matylda Schlichtinger has omitted to mention that the human body also emits detectable amounts of THz, mm, and microwave radiation due to its temperature, as well as lower frequency electromagnetic signals.
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If particles cannot move faster than light then points of a wave function must be discontinuous in time and distance. Because, all near points where a particle has a non-zero probability of existence must be far enough apart in time and distance so that a particle cannot break the speed of light by tunneling. Deferential equations do not give such solutions.
I mean a bona fide Classical barrier exhibiting a usual classical turning point,
where a potential barrier is higher than the kinetic energy of some trapped particle. What, are you pretending Q tunneling does not exist?
Well, I admit that the speed is not that well defined, uncertainty principle.
You cannot inject your classical ideas very much in this.
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Very low frequency electromagnetic and gravitational waves have quantums of low energy and momentum. Therefore, they have large uncertainties in position and time hence they should move by quantum tunneling a lot. Unless quantum tunneling limited to the speed of light, Some of their quantums should have be going faster than light. By tunneling, i mean having at any one time non-zero probability of existing at many points from their wave functions. The fact they have not been shown to go faster than light appears to show valid wave functions would only give points of existence separated in time and space such that the speed of light is not broken.
The solutions by Schrodinger's equation would 3 a wave functions zero in the gap. The gap surface therefore would be reflectors for the solution on each side of the gap. On each side of the gap it would take the form B(t,x,y,z)-B(t,,x,y,-z) where z is normal to gap wall, and B is a function.
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For a wave function to be valid where it gives a particle a non-zero probability of existence must be separated in time and distance so that it can only go between those points at speed les than light. That includes by quantum tunneling.
However, once more, the statement about a particle being in two places at once is wrong.
That a particle has a non-zero probability of being somewhere doesn’t mean it’s at more than one place at once. It’s astonishing how this nonsense persists.
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I have S11 parameter only in my design, as I have a single wave guide port excitation . How could I extract eps and mu from S11 in CST? or by matlab coding? I appreciate your help .
Yes Mr eduardo. I have to redesign with 2 ports as many papers I have seen recently.
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There are indeed many models of the value of elementary electric charge origin, but all of them have introduced other types of new phenomena.
I solved this problem only based on the phenomena that are known and have been measured, in:
It is an article related to electric charge, Hubble's constant, fine structure constant, wave function collapse and reveals the quantified nature of spacetime, but please give more time and patience to read the material to the end, to see how beautifully come all these together (constants), forming a unitary whole (one theory).
Thank you very much for your support!
"I can send you a link about how RG became the wonderful place to start open discussions on every topic in science possible."...I opened this dialog...for discussions....I like constructive criticism...and I noticed that it is practiced on RG....with some exceptions...
"The least thing we all need here is some personality war on how clever you think you are and how much you know - or not - and in the form you did."
I didn't start a "personality war", and I hope that my answers can't be interpreted like that...if it is, I apologize....
I admit, I can be wrong, but I don't attack the person...
Thank you once again!
Respectfully,
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I'm simulating a Vivaldi antenna array. There is a vibration wave of S parameter at low frequency. It can't be removed when I select the adaptive mesh of time domain solver. Actually, it doesn't happen only in this simulation. I also see it when I simulate a very simple square patch antenna.
Look at the field or current patterns at the resonance frequency. Maybe it is the frequency at which the whole patch is resonant.
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Hi everybody.
I have developed within my research a 3 dimensional numerical wave tank (25 meter long, 10 meter wide and 6 meter water depth) in LS DYNA based on the ICFD method. I have already refined the mesh in the area where the wave acts to increase the accuracy of the wave deflection. At the outlet of the wave tank I have installed a numerical damper to minimize the reflection of the wave.
Now i have evaluated the results at 3 different locations (5m, 10m and 15m) and it is noticeable that energy is lost in the system. The wave deflection decreases at the results at 10m and 15m compared to the results at 5m. Reason for this could be numerical dissipation and numerical dispersion.
My idea now is to either increase the tank length to minimize the influence of the reflecting wave or to adjust the parameters of the linear and quadratic damping terms.
Does anyone of you know about similar problems and has some suggestions for me?
Thanks,
Jonas
Numerical dissipation and dispersion, as you say, mainly happens for two reasons: (i) insuffiecient number of cells per wave height/length (ii) inappropriate turbulence model.
I do not have any experience with ICFD within LS-DYNA but you should definitely test the results with more cells in the free surface area. Check the courant number not to exceed at least 0.3 in the FS area. Regarding turbulence models, the best but not ideal "out of the box" model for wave propagation is realizable k-E. If you wish that your simulations are long, then you will need different, more stabile turb. model.
All the best and good luck,
Ivan
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The results of our research determined for the first time that for the entire frequency range of acoustic waves, the range of their propagation, measured not in units of measurement of distance, but in cycles, is a constant: the same number of cycles corresponds to the same absorption of acoustic energy. Due to the difference in the lengths of acoustic waves, the range of sound propagation is determined by the wavelength, which for the conditions of the practical absence of sound dispersion in water, has a statistical relationship with the wave frequency. Due to this, the researchers got the wrong impression about the dependence of the sound propagation distance on the frequency. But the presence of correlation in this case is not related to the presence of a cause-and-effect relationship between the frequency of acoustic waves and their propagation distance. Thus, for the first time, the basis for a complete rethinking of the theory of the process of absorbing the energy of acoustic waves in water is presented.
It should be noted that there are signs that the obtained regularity can be extended to transverse waves in water. This is evidenced by the fact that, unlike shorter wind waves, long ocean surface (transverse) waves of "surge" spread over a distance of more than 1000 km. Tsunami waves, which have a length greater than the length of "Zibu" waves, spread over a distance of tens of thousands of kilometers. Seismic waves that propagate in the solid shell of the Earth, at lengths close to the length of tsunami waves, also propagate for tens of thousands of kilometers. In the future, different types of waves propagating in different environments can be considered, which does not exclude the possibility of confirming the general (universal) physically justified and understandable regularity of wave attenuation put forward by us.
Howdy Borys Kapochkin,
My wife told me about the joy/sorrow event of an earthquake close to home there. Nature is unaware of kindness ~Tao Te Ching. You may enjoy learning while you experience sorrow: survivors in centuries to come will benefit from what you learn by study of the current events that are tragic for today's casualties .
I had been concerned about the emphasis that developed in this thread on pressure that does enhance evaporation, since it is only a small effect, while "that lucky old sun" is far more important in supplying energy for the molecular unrest. When you again have time for evaporation it will be good to feel the energy in the molecular unrest without undue emphasis on pressure. Just a thought for future discussion.
Happy Trails, with sympathy for unhappy experiences, Len
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EEWS - a method of scammers to spend the budget without benefiting people?
EEWS and its "modifications" start from the moment that "there was an earthquake". (Method "p" - "S" is its analog, only other waves of ALREADY OCCURRED EARTHQUAKES are taken).
Several times I exhibited these methods that do not warn about the time, place, or strength of a future earthquake, and I asked scientists to show all the good and useful things that are in these methods.
No expert has claimed the beneficial properties of these methods.
Maybe then it is necessary to declare that only scammers use this method.
After all, what is spent on these senseless methods could be used for the benefit of people. Approximately the same was said at a meeting of the Commission of the Israeli Knesset in 2005.
Интересно:
Геофизики боятся признать очевидный факт?
Или все согласны, что это мошенничество?
Interesting:
Are geophysicists afraid to admit the obvious fact?
Or does everyone agree that this is a scam?
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Hi everyone,
I have 1.5 mL eppendorf tubes with nanoparticle pellets in water (ZIF8, UIO-66 and UIO-66-PEG). No matter how hard I try to homogenise them into single nanoparticles, using pipetting up and down and vortexing, they immediately clump into a pellet. Do you think that if I put an eppendorf tube with these NPs into a waterbath sonicator, it would be possible to break these clumps into single NP-solution without forming clumps?
Would the walls of eppendorf tube absorb the sonic waves and therefore prevent efficient nanoparticle homogenisation?
Thanks,
Kind regards,
Maria
Yes, sonication can be used to break down the clumps of nanoparticles into single NP-solutions without forming clumps. Sonication creates rapid, high-energy sound waves that cause cavitation in liquid, resulting in a very effective form of homogenization. When done carefully and at the proper duration, sonication can break down larger particles into smaller particles, which reduces the size of the aggregates and prevents clumping of the nanoparticles.
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I know that for Lame potential, we get finite number of bands and band gaps, unlike kronig penney model which shows infinite bands and band gaps. I know by analytically solving the Hill's equation for Lame potential, we find finite band edge wave functions. But how to physically understand the phenomenon of band gap collapse after a certain number of band gaps, such that there exists only finite no. of bands ?
Thank you Sir for the detailed explanation. It would be a great help if you could suggest some references regarding this matter to understand the band gap collapse.
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Hello, I am a researcher working on GNSS Interferometric Reflectometry (GNSS-IR). The signal segments we work on may not always contain many waves. Hence, I need an expert opinion on how I should proceed in such a situation. My questions are as follows:
1. How many full waves are required to accurately estimate the frequency of a signal segment?
2. Is there a conventional criterion for the minimum number of waves?
3. Is it possible to express the accuracy of an estimated frequency with a quantity derived from the spectra or periodogram (such as the peak width)?
Regards.