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# Physics Education - Science topic

For researchers on physics education and science education.
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For a plate capacitor the force on the plates can be calculated by calculating the change of field energy caused by an infinitesimal displacement. Looks like a very first principle. However, thinking about a displacement of a charge in a homogeneous electric field seems to explain no force at all...
sorry to say, but I do not understand anything of your theory. Furthermore I see no explanation of the force on a charge in an E field.
Best regards
Jörn
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I am worried.
Hello, again, Dulli Chandra Agrawal
I would suggest that you could contact that particular journal (eg email the office or office assistant/administration) to clarify.
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Apart from becoming Physics teachers, what other career prospects are there for graduates of Physics Education?
With the recent advancement of online studies and virtual learning platforms, physics education major became a field where the use of new AI, programming and visualization skill can be combined, studied and used for the development of new ways to teach and learn in an interactive way, I guess.
There are already successful examples with the help of HTML5
Best Regards.
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Dear RG specialists, I am wondering if is there a phase transition to a localized transversal phonon sort of coherent state? We know that there is one for the diffuse photon field when light scattering becomes strong enough (frozen light limit [1,2]).
This question arises only for transverse waves [3,4].
Following [1] Frozen light, Sajeev J. Nature volume 390, pp. 661–662, 1997:
Are there strong interference effects, due to the wave-like nature of transverse phonons, which severely obstruct their diffusion?
We already know that electrons & photons can be localized, please see the following articles & references therein:
The following research article is related to this thread:
Best Regards.
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I am asking this question on the supposition that a classical body may be broken down in particles which are so small in size that quantum mechanics is applicable on each of these small particles. Here number of particles tends to uncountable (keeping number/volume as constant).
Now statistical mechanics is applicable if practically infinite no. of particles are present. So if practically infinite number of infinitely small sized particles are there, Quantum Statistical Mechanics may be applied to this collection. (Please correct me if I have a wrong notion).
But this collection of infinitesimally small particles make up the bulky body, which can be studied using classical mechanics.
There is no difference Prof. Manish Khare, we have two windows to watch the physical world, the classical & the quantum approaches, but there is a window, they are the Wigner probabilistic distributions.
Best Regards.
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Dear and Distinguished Fellows from the solid-state physics RG community.
Does have anyone read after 20 years the preprint from Prof. Laughlin A Critique of two metals?
I read it when I was a PhD student. I think his opinion after 20 years deserves more attention. Please, feel free to follow down the link to the arXiv preprint if somebody has an interest and please leave your opinion:
This paper is related to this thread:
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Dear Sirs,
The elevator example in general relativity is used to show that gravitational force and an inertial force are not distinguishable. In other words the 2nd Newton's law is the same in the two frames: inertial frame with homogenous gravitational field and the elevator's frame without gravitational field which has constant acceleration in respect to the inertial frame.
But every one knows that an inertial force is a force which does not obey the 3rd Newton's law. For example such forces are cetrifugal force and Coriolis force existing in the Earth reference frame. Gravitational force satisfies the 3rd Newton's law. So one can conclude that the gravitational force is not inertial.
Could you clarify the above controversy.
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Dear Sirs,
R Feynman in his lectures, vol 1, chapter 12, Characteristics of force wrote:
"The real content of Newton’s laws is this: that the force is supposed to have some independent properties, in addition to the law F=ma; but the specific independent properties that the force has were not completely described by Newton or by anybody else, and therefore the physical law F=ma is an incomplete law. ".
Other researchers may consider the 2nd Newton's law as a definition of force or mass. But R. Feynman did not agree with them in the above chapter.
What is your view on the 2nd Newton's law?
Dear Mr khripov,
I prefer that we agree on the questions you ask.
For me F'=-kx is Hook's law.
For me F=ma is Newton's second law.
If in a given problem F=F', then -kx=ma.It is Newton's law particularized to the case where the force applied is that of a spring (Hook's law).
At static equilibrium, we have theoretically kx=mg. The theory tells you that kx=mg.
You want to check this relation experimentally. Fabricate identical objects of the same mass m. Hang on the spring one object, then two objects, then three objects, etc.... At the first elongation mark the elongation with a pen x=X0. You will notice experimentally that for 2m you will have an elongation of 2(X0), for 3m you will have 3(X0), etc ..... Plot on a graph the elongation of the spring as a function of the hooked mass. You will see that the curve is a straight line and that the slope of this line is (1/k) in the system of units you have used.
Conclusion:
1) You have therefore verified the linearity of x as a function of m and this is the verification you wanted to make.
2) You have deduced the value of k.
Important remark:
Clearly, the measurements you have made do not depend on any law (including the law of the relation you want to verify).
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Dear Sirs,
Everyone knows the derivation of Lorentz transformations from electromagnetic wave front propagation. But Lorentz transformations are the basis of the general mechanics theory. It seems to me it is logically correct to derive the transformations from purely mechanical grounds. But how to do this? Mechanical (sound) waves are not of course applicable here. Or there is only purely mathematical approach? I The later is also not good in physics. Could it be derived from gravitational wave propagation? If it is so is there any controversy because General relativity is based on special relativity? I would be grateful for your suggestions.
Length contraction CAN be deduced by purely mechanical processes. The other Transformations are substituted by other mechanical means. For example, time dilation can be speed of light changes in different media density.
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Dear RG community, this review thread is about the role of RKKY interaction in solid-state physics. I want to learn more about it. I would like to know for example, what physics effects RKKY describe well.
The RKKY exchange interaction (Ruderman - Kittel - Kasuya - Yosida) is defined as an indirect exchange interaction between magnetic ions, carried out through itinerant conduction electrons.
In rare-earth metals, whose magnetic electrons in the 4f shell are shielded by the 5s and 5p electrons, the direct exchange is rather weak and insignificant and indirect exchange via the conduction/itinerant electrons gives rise to magnetic order in these materials.
Some initial clarifications:
1. For this thread, the are two types of electrons: itinerant or conduction electrons and localized electrons.
2. Indirect exchange is the coupling between the localized magnetic moments of magnetic metals via the conduction electrons, while direct exchange occurs between moments, which are close enough to have sufficient overlap of their wavefunctions.
RKKY interaction takes place in metals and semiconductors, where itinerant electrons mediate the exchange interaction of ions with localized oppositely directed spins, partially filled d and f shells.
The physical mechanism is the following: Conduction/itinerant electrons interact with the effective magnetic field of the i-th site of the crystal lattice and acquire a kind of spin polarization. When passing through the next lattice site, relaxation of the magnetic moments of the electron and the site will cause mutual changes in both the spin polarization and the spin of the lattice site.
Hereby, RKKY can be described using the concept that conduction electrons move in an effective field created by a localized magnetic moment of one site.
[1] M.A. Ruderman and C. Kittel, Phys. Rev. 96, 99 (1954).
[2] T. Kasuya, Prog. Theor. Phys. 16, 45 (1956).
[3] K. Yosida, Phys. Rev. 106, 893 (1957).
[4] D. I. Golosov and M. I. Kaganov, J. Phys.: Condens. Matter 5, 1481-1492 (1993).
The following paper is worth mentioning in this thread:
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Dear Sirs,
I would like to find out whether galilean relativity principle (which means the same
form of three Newton's laws in all inertial frames) is derived from the three Newton's laws or
any other classical mechanics statements.
Dear Anatoly,
If you are satisfied by the 1st Newton's law, which is basically equivalent to Galilean relativity, there is nothing to prove.
But if you mean to axiomatically construct a logically self-consistent mechanics without Galilean relativity, like non-Euclidean geometries proposed by mathematicians in 19th century, that should be possible, of course.
There are plenty of mechanical systems without translation invariance - a pendulum, a bent railway, a body in an "irremovable potential field", etc. But they are used to be well handled by existing formalism: systems with nonlinear constraints - by Lagrangian, potential motions - by Hamiltonian.
So, it is unobvious whether there is need for something new physically. And mathematically, it must be just part of non-Euclidean geometry, already well developed.
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Dear RG members:
Screenshot from:
Vonsovskii, S. V. and Svirskii, M. S. 1961. About the spin of phonons. Soviet Physics of the Solid State. 3:2160. In Russian.
Do you know any article/book which uses explicit expressions containing Anisotropic Elastic Langragians L( Cij )?
For instance: cubic, hexagonal, or tetragonal ones? Other symmetries are also welcome.
L can be written in the 4th index range - ijkl or Voig - ij notations, but the math expressions must contain explicitly the elastic stiffness components Cij or compliances Sij (if S-1 C ~ 1) according to the point symmetry group.
For example: in the isotropy case: 2, in the cubic case 3, in the hexagonal case 6 and so on.
A lagrangian is defined as L(Cij) = K( ρ v2 ) - U( Cij ), therefore the potential term U(Cij) does have to include an expression invariant to the point group symmetry considered.
I did an intensive search on the web, so far only two papers with two expressions (isotropic and cubic cases) both papers from the '60s.
Thank you all so much for the interest.
I have públished a preprint with the answer to this thread. The Lagrangian for D4 point group symmetry.
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Discussion of the state of art on the application of the Ertel's potential vorticity theorem in atmospheric physics & physical oceanography.
Prof. H. Ertel generalized Rossby's work proposal of 1939. Prof. Rossby firstly proposed that instead of the full three-dimensional vorticity vector, the local vertical component of the absolute vorticity is the most important component for large-scale atmospheric flow.
Via an independent paper published in 1942, Prof. Ertel identifying a conserved quantity following the motion of an air parcel proved that a certain quantity called the Ertel potential vorticity is also conserved for an idealized continuous fluid.
A very complete review on Ertel potential vorticity theorem, thank you for suggesting its reading, Prof. Aref Wazwaz .
Best Regards.
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Hello Dear colleagues:
it seems to me this could be an interesting thread for discussion:
I would like to center the discussion around the concept of Entropy. But I would like to address it on the explanation-description-ejemplification part of the concept.
i.e. What do you think is a good, helpul explanation for the concept of Entropy (in a technical level of course) ?
A manner (or manners) of explain it trying to settle down the concept as clear as possible. Maybe first, in a more general scenario, and next (if is required so) in a more specific one ....
Kind regards !
Dear F. Hernandes
The Entropy (Greek - ἐντροπία-transformation, conversion, reformation, change) establishes the direct link between MICRO-scopic state (in other words orbital) of some (any) system and its MACRO-scopic state parameters (temperature, pressure, etc).
This is the Concept (from capital letter).
Its main feature – this is the ONLY entity in natural sciences that shows the development trend of any self-sustained natural process. It is the state function; it isn’t the transition function. That is why the entropy is independent from the transition route, it depends only from the initial state A and final state B for any system under consideration. Entropy has many senses.
In the mathematical statistics, the entropy is the measure of uncertainty of the probability distribution.
In the statistical physics, it presents the probability (so-caled *statistical sum*) of the existence of some (given) microscopic state (*statistical weight*) under the same macroscopic characteristics. This means that the system may have different amount of information, the macroscopic parameters being the same.
In the information approach, it deals with the information capacity of the system. That is why, the Father of Information theory Claude Elwood Shannon believed that the words *entropy* and *information* are synonyms. He defined entropy as the ratio of the lost information to the whole of information volume.
In the quantum physics, this is the number of orbitals for the same (macro)-state parameters.
In the management theory, the entropy is the measure of uncertainty of the system behavior.
In the theory of the dynamic systems, it is the measure of the chaotic deviation of the transition routes.
In the thermodynamics, the entropy presents the measure of the irreversible energy loss. In other words, it presents system’s efficiency (capacity for work). This provides the additivity properties for two independent systems.
Gnoseologically, the entropy is the inter-disciplinary measure of the energy (information) devaluation (not the price, but rather the very devaluation).
This way, the entropy is many-sided Concept. This provides unusual features of entropy.
What is the entropy dimension? The right answer depends on the approach. It is dimensionless figure in the information approach (Shannon defined it as the ratio of two uniform values; therefore it is dimensionless by definition). On the contrary, in the thermodynamics approach it has a dimension (energy to temperature J/K)
Is entropy parameter (fixed number) or this is a function? Once again, the proper answer depends on the approach (point of view). It is a number in the mathematical statistics (logarithm of the number of the admissible (unprohibited) system states, well-known sigma σ). At the same time, this is the function in the quantum statistics. Etc., etc.
So, be very cautious when you are operating with entropy.
Best wishes,
Emeritus Professor V. Dimitrov vasili@tauex.tau.ac.il
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Dear Fellows I checked very recent literature for the P-T phase diagram by means of exp. measurements on Metallic Hydrogen.
I found several interesting papers that show its metallic phase at high pressure: Any comments please? are there any new DFT calculations for a Metallic Hydrogen P-T Phase Diagram?
1. Metallic hydrogen F Silvera et al 2018 J. Phys.: Condens. Matter in press https://doi.org/10.1088/1361-648X/aac401
Figures 6 and 8
2. Insulator-metal transition in liquid hydrogen and deuterium
Shuqing Jiang, Nicholas Holtgrewe, Zachary M. Geballe, Sergey S. Lobanov, Mohammad F. Mahmood, R. Stewart McWilliams, Alexander F. Goncharov arXiv:1810.01360v1
Fig. 5
3. Theory of high pressure hydrogen, made simple Ioan B Magd˘au, Floris Balm and Graeme J Ackland
IOP Conf. Series: Journal of Physics: Conf. Series 950 (2017) 042059 doi :10.1088/1742-6596/950/4/042059
Fig. 1
4. Observation of the Wigner-Huntington transition to metallic hydrogen Ranga P. Dias, Isaac F. Silvera
Science  17 Feb 2017: Vol. 355, Issue 6326, pp. 715-718 DOI: 10.1126/science.aal1579
Fig 1
The following publication deserves special attention in this thread:
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Dear Sirs,
The 1st law in Newton`s principia are now understood as two statements: the determination of inertial frame reference (if F=0 then a=0 and if F is not equal 0 then there is some body accelleration "a"); there is in nature at least one inertial frame reference. Theoretically I can understand it a little bit. As we have such a determination of inertial frame reference then the 2 nd Newton law is not directly followed from the 1 st law, or this determination is partly independent of the 2nd law. So it looks like logically good.
But what we have in experiment? I do not know whether there is any research on experimental determination of any particular inertial system (like International Celestial Reference System) using the 1 st Newton law. So in practice we use the 2 nd law (e.g. school example - foucault pendulum plane rotation). Could you clarify on the experimental and theoretical determination of inertial frame reference. You know there are teachers that see the 1st law as the consequence of the 2nd law.
The Galilean invariance, Dr. Anatoly A Khripov, the laws of motion are the same in all inertial frames if there is no acceleration due to an external force. But sometimes a conservation law (momentum, or energy) is needed experimentally to be tested.
For example, the capillary movement without viscosity of the 4He isotope is based on the Galilean invariance of energy and momentum, despite it is a quantum liquid, showing how general is the Galilean invariance.
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We are living in a world that sometimes two brothers or sisters may not understand each other. In such a situation, a number of historical records, literature phrases, and similar subjects may get confused or misused.
The question is here how physics may solve those kinds of difficulties.
Sure. For example, the emissions of night lights maps contribute to an understanding of the geographic distribution of the population. The spectral emissions based on physical foundations.
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The basics of electronic conductivity can be explained without inciting quantum mechanics or brillouin zone- simply by virtue of outermost free electrons of metallic elements (from electronic configuration) and overlapping of energy bands as many metal atoms come close to one another. The similar approach for electrical conductivity does not apply too good for ceramics, because it is nearly impossible to explain delocalized electrons in ionic/covalent bonded material in terms of basic chemistry (say 10th to 12th grade level) without inciting QM, VBT-MOT and Brillouin zone; and it is hopeless task to locate position of electronic band for ceramics with simple Bohr theory of Atom (e.g. Rydberg ionization equation).
So, How can I preliminarily explain electrical (both ionic and electronic) conductivity of ceramics in a language familiar with (preliminary) origin of band structure in metals? I do not want deep Quantum Mechanics or Brillouin Zone explanation at this level.
Dear Sumit Bhowmick, you can use the semiclassical and geometrical approach of Lifshitz and Kaganov to explain conductivity in normal metals.
I don't know any related works in ceramics, where the Fermi surfaces can be open. However, there are the so-called molecular conductors.
Electron theory of metals and geometry by M. I. Kaganov and I. M. Lifshits Usp. Fiz. Nauk 129, 487 529 (November 1979)
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Considering the context of the COVID-19 pandemic that requires remote teaching activities. In the case of Chemical Education, which requires a high degree of abstraction and the use of visualizations can effectively contribute to the student's learning process, how does the teacher deal with the relationship of macro, micro and symbolic representations, in online teaching?
I think that the teacher can use some applications that are online intended for learning the nomenclature, elaboration and spatial representation of molecules. There are also reaction simulators and laboratory practices where through color change you can explain and discuss with students the causes of a color change or a gas release. Also the teacher and students can make representations through animation programs that are useful to represent (model) some change or transformation of the matter.
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What is the best way to teach physics? And what methodology could be adopted? Share your opinion or experience so that we can enhance our teaching whether in the classroom or even in the daily life of our social relationships.
To teach only distinguished students by any way even if you are failing Teacher. Such students are independents
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I am referring to the use of computer science for education purposes.
Indeed it does Dear Prof. Mukesh Kumar,
Computational science increase students' and teachers' knowledge.
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Could you please suggest me some articles with these preconceptions discussed?
In addition to all interesting answers in this thread, there is a book on physics education and misconceptions of students regarding many topics in elementary physics including preconceptions on kinetics and dynamics:
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One of the consequences of relativistic physics is the rejection of the well-known concepts of space and time in science, and replacing them with the new concept of Minkowski space-time or simply space-time.
In classical mechanics, the three spatial dimensions in Cartesian coordinates are usually denoted by x, y and z. The dimensional symbol of each is L. Time is represented by t with the dimensional symbol of T.
In relativistic physics x, y and z are still intactly used for the three spatial dimensions, but time is replaced by ct. It means its dimension has changed from T to L. Therefore, this new time is yet another spatial dimension. One thus wonders where and what is time in space-time?
Probably, due to this awkwardness, ct is not commonly used by physicists as the notion for time after more than a century since its introduction and despite the fact that it applies to any object at any speed.
The root of this manipulation of time comes directly from Lorentz transformations equations. But what are the consequences of this change?
We are told that an observer in any inertial reference frame is allowed to consider its own frame to be stationary. However, the space-time concept tells us that if the same observer does not move at all in the same frame, he or she still moves at the new so-called time dimension with the speed of light! In fact, every object which is apparently moving at a constant speed through space is actually moving with the speed of light in space-time, divided partially in time and partially in spatial directions. The difference is that going at the speed of light in the time direction is disassociated with momentum energy but going at the fraction of that speed in the other three dimensions accumulates substantial momentum energy, reaching infinity when approaching the speed of light.
Dear Prof. Ziaedin Shafiei
As a conservative physicist & non-expert in relativity, I would like to answer your question in the following way, as it is elaborated in Landau & Lifschitz classical book: the Classical Theory of Fields. They introduced the idea of the light cone many years ago to described events in space-time in a general way. For them: time is an axis, space is another axis & 1/c the inverse speed of light is the slope of the plot. Hereby, my answer is: t is the time.
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It is noticed recently, that a considerable number of physics Lecturers rely mainly on IT technology in their lectures and conduct all examinations online. I think, their action is not acceptable as far as a good asessement were concerned. Since Physics exams should contain Both Multiple choice and detailed questions of Physics.They do not bother marking the exam papers, because it is done by computer.
For the actual crisis, online physics examinations can be adopted Prof. Fakhri Abdul Salam Al-Ramadhan
To adapt appropriately, there are some VLP such as Khan Academy that offer physics courses with proven paths to examinations:
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Einstein, based on his argument in section 6 of 1905 paper, claimed:
“If a unit electric point charge is in motion in an electromagnetic field, the force acting upon it is equal to the electric force which is present at the locality of the charge, and which we ascertain by transformation of the field to a system of co-ordinates at rest relatively to the electrical charge.”
Simply, total electromagnetic forces, acting on a moving charge, claimed to be equal calculated in any inertial reference frame; F’ = F.
Using an example, Feynman, in his lectures, failed to prove that electromagnetic forces are equal if calculated in the two inertial frames suggested by Einstein.
His result was F’ = γ F
Why did Feynman fail? Can you find an example to support Einstein’s claim?
Attached file presents and reviews Feynman’s analysis and calculation.
It is an interesting point Prof. Ziaedin Shafiei
Prof. R. Feynman has some issues about some applications of electromagnetism.
For example: According to Prof. Paulo Roberto Silva, in his famous lectures Prof. Feynman didn´t derive the Drude model for the electrical conductivity. We know that he worked a lot on superconductivity, and in the section called: Tensors chap 31. of 2 Volume Feynman Lectures, he briefly talks about the conductivity tensor j=σ E, but he calls it as tensor of inertia in analogy to the moment of inertia & there he stops to elaborate further. No mention to the Drude model.
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I am investigating any study to make new views for me about education in nuclear. For example some training courses may be effective for students or their parents. So  i need some help.
Nice Dear Panji Aji
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What are the main factors associated with physical activity during middle or high school physical education?
Nice Dear Harshvardhan Singh
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Other than single relaxation time how Debye type behaviour effects the electrical properties of amorphous semiconductors particularly chalcogenide glasses?
Following.
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My question is Can we attain 50-60 Hz Sound frequency on flowing water through tubes? while in background pump is working or other sounds are there (no noise cancellation).
What happens if we have high crossflow velocity of the water lets say 2 to 3 m/s.
Nice Cotribution Franklin Felber
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Dear Sirs,
Everybody knows plane and spherical wave solutions of Maxwell equations, e.g for decaying plane wave E=E0*exp(-kx)*cos(w(t-x/v)). But seems to me they give the unreal situation that the wave amplitude is nonzero at different points of space at given time moment. Could you advise the experiment or natural phenomenon which produces such a wave in nature?
Maybe we have infinte speed of the EM interaction? Do you know any real solution of Maxwel equations which exists only in one space point at the given time moment? Maybe using delta function? Or maybe there is my mistake?
Nice Dear Joaquin Diaz-alonso
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In my microbal fuel cell work, when I am running MFC I measure output by using a multimeter and I am able to measure only current or only Voltage at one time. When I measure both at a onetime the voltage suddenly falls to zero, and the current drops also.
Can any one help me understanding this concept?
How can i solve this problem?
thank you.
Following
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Current undergraduate project to determine effects of equipment manipulation in physical education lessons in badminton for 10-12 year old on; physical activity levels, perceived physical competence, motivation and physical education enjoyment.
Following
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Physics students achievement.
Nice Dear Yahaya Isa Bunkure
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I want to learn from this group
Following
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On the internet, we find several options of smartphones & tablets apps for playing games with physics and mathematical concepts. Which ones have you already used and would recommend for the use in the basic & high schools?
Some researchers on 'Science Education' have been studying their use already and have made public some of their presentations about these works. Would you have some recommendation of researchers to be contacted that have been working on this topic?
I can recommend to look at Khan Academy appl Dear Prof. Jair Ricardo De Moraes
In my humble opinion KA-VLP is a good one, it has several online tools for teaching & learning: for instance, I directly quote an external web link [1]:
• Khan Academy allows for students to self-pace through material, and scales material based on student progress, something that is impossible in a traditional classroom.
• Students can be linked to “coaches” who can be their classroom teacher, a parent, a tutor, or a peer-tutor.
• The coach can track student progress and intervene and make suggestions based on student progress.
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In the theory of relativity the upper bound of velocity is included by using the Lorentz transformation. Therefore the theory of relativity can give no answer to my why question. However, in my preprint I explain why:
In theoretical electrical engineering you learn that the group velocity of electromagnetic waves in wave guides can not exceed c. The reason is the electromagnetic properties of empty space and the group velocity of electromagnetic waves. This is derived without needing the Lorentz transformation.
Dear Colleagues,
This point is treated in electromagnetic wave propagation. The speed is limited by the transfer of energy from the magnetic form to the electric form and vice verse.
It is so that the wave is propagated by when the magnetic field collapses it builds the electric rings in the side space and when the electric rings collapse they build
magnetic rings beside them. This this build and collapse lasts some time then the waves takes time to propagate a specific distance.
Best wishes
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One remembers, first, that all matter used in anything is constructed of atoms, where atoms are made of particles, where quantum mechanics (QM) physically works.
Any physics, chemistry, engineering, computer science, even mathematics -- where the electrons, light, wave, and number behaviors are determining these fields by Nature -- will obey quantum rules, such as NO "law of the excluded middle" and NO "axiom of choice", and where QM principles play main roles.
One reads, for example, at Stanford U. that: the concepts and techniques of quantum mechanics are essential in many areas of engineering and science such as materials science, nanotechnology, electronic devices, and photonics.
Nominations by participants here (in order of appearance) include:
Superfluidity, superconductivity, HVDC with QM rectification by a thyristor (semiconductor), incandescence, laser, quantum decoherence, entanglement, P-type or N-type semiconductors, transistor radio, and the entire known universe for 13.8 billion years so far.
What is your reasoned opinion? What is your best example of QM having visible effects on microscopic and macroscopic scales?
One thing that comes to mind in regards to your primary question is hydrodynamic quantum analogs. These experiments were done at MIT in July of 2013 published in Physical Review Letters E. Dr. Daniel M. Harris displayed that "a coherent wavelike statistical behavior emerges from the complex underlying dynamics and that the probability distribution is prescribed by the Faraday wave mode of the corral." I hope this helps!
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Having announced that I am preparing a new Physics text
Update 2 is a tentative chapter list.
I would be interested in hearing from people as to Freshman mechanics topics you would like to hear discussed.
With a slight invocation of LaTeX, the book is based on two equations.
\vec{F} = \frac{d \vec{P}}{dt}
PHYSICS - CALCULUS = TOTAL NONSENSE
What will be new?
First, the book will be affordable. I am targeting $15 or$20 as a final price for a paper book that covers a semester of mechanics including harmonic motion. The possibility of a lower price in the third world is not ruled out.
Second, the text will be based on symbolic reasoning. Yes, there will be folks saying that their students haven't learned how to work symbolic problems yet. Well, it is time that they learned, isn't it? By the way, how are they passing calculus?
At more length, my text will actually be calculus based. "Calculus-based" means that students will need to use calculus to work homework problems and solve exam questions. As 'calculus-based' is required by some accrediting agencies, textbooks that pretend to be calculus-based but in which students only do numerical work buried under masses of unit conversions are now going to be challenged to be acceptable.
Hidden in symbolics and calculus is the use of vectors. Space is three-dimensional, and problems will match. Momentum and angular momentum are axial and polar vectors, not scalars, and will be treated as such.
In a certain sense, the book will represent a radical change in how physics is taught, at least relative to many places that now teach freshman physics.
Interesting Prof. George Phillies Thanks for sharing. I saw the Project Log. Two questions. First Q. what about conservation laws in mechanics? Second Q. simbolic manipulation with a math GNU tool or a physics tool? Regards.
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Dear Sirs,
The setup for the dispersion measurement is as follows. Hg lamp, collimator, goniometer with triangular prism. We measure the light dispersion using the prism. To do so we determine the minimal deviation angle of the particular color line and then calculate the refraction coefficient (the wavelengths are known from the standard source). To find the minimal deviation angle we rotate the prism.
In the above setup does anybody know whether the smooth minimum of the deviation angle (as a function of incidence angle) can increase the error of the measurement of the minimal deviation angle? Please correct me if there is a mistake.
For the general case of refraction in a prism spectrometer, the angle of deflection depends on the refractive index of the prism, the vertex angle of the prism, and the orientation of the prism with respect to the incident beam.
The angle of deviation is a minimum when the prism is aligned symmetrically with respect to incident and refracted output beam directions. In this orientation the deviation depends only weakly on the rotation of the prism. To calculate the refractive index, we need only the deviation angle φ, and the prism vertex angle, θ.
n = sin( (θ+φ)/2 ) / sin(θ/2)
A small error, ε, in the prism orientation gives rise to a much smaller error in the deflection angle, proportional to the square of the orientation error ε2. In practice, with reasonably careful adjustment, this error can be neglected.
I don't see how the minimum deviation angle could be made more sensitive to prism rotation, but if this were possible, it would increase the errors arising from measurements of the prism alignment.
The deviation angle does become extremely sensitive to incident angle when the internal refracted ray approaches the critical angle at either the entrance or exit face of the prism. The deviation angle is a maximum at the critical angle, where the beam will mostly be reflected rather than refracted through the prism.
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Do the theories of education suitable for scientific subjects such as math, physics, chemistry, etc...?
It seems clear that most of the developing countries and some of the developed ones use the theories of educations and obligate their teachers to train on some of these theories, Do these theories suitable for non-literature such scientific subjects? Some trainers say that these theories could be used for scientific subjects with little modifications. However, from my experience in the real classroom, the 21st-century methodologies of education which based on gaming much more than traditional education show bad results in the students' knowledge and their academic background. In my opinion, the bad results are due to unsuitable or incomplete educational environments such as apathy of students as well as teachers toward education -teaching and learning-, teacher ability to control the classroom, and number of students per classroom versus the period length of the lesson and the activities amount that required to deliver the lesson.
What are the particular strengths of developed countries such as Singapore’s instructional regime that helps it perform so well? What are its limits and constraints? Is Singapore’s teaching system transferable to other countries?
I taught at the National Institute of Education in Singapore from 2003 to 2008. All Singapore science teachers are trained at the National Institute. My area of interest was in primary science education (grades K-6) . The training of primary teachers focused on preparing them to teach a specific curriculum, the national curriculum. The Singapore primary science curriculum model aligned closely with the Science Curriculum Improvement Study (SCIS) developed in the US in the 1960's. Science Content, Science Process Skills and Science Themes gave structure to the K-6 curriculum. Singapore adapted the SCIS model to make the science content more rigorous and strengthened both the science content and process skills by adding accountability through assessment. I believe the structure of the Singapore's primary science curriculum can be successfully adapted and implemented in other countries. One particular strength of the Singapore primary science curriculum is its success in preparing students to pass the high stakes, national, 6th grade leaving test. The problem solving ability required in this test correlates highly and often surpasses that required in many international exams such as the TIMMS. There are limitations, such as the narrowing of the curriculum to what is covered in tests, and cultural constraints. As you point out, educational environments and resources play a large factor in the successful transfer of such structured curricula and their underlying theories.
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Dear Sirs,
Could anybody help to solve the following task?
Let us have two different inertial masses, say different in 2 times. Point masses are good also. Each of them is pulled by a string (constant force). To solve the problem we should use Einstein equations as every inertial mass possesses a kinetic energy and therefore curve space-time around itself. Did we receive the accelerations of each body which differs in 2 times? So maybe here we get a contradiction in GR?
Thank you very much
I badly explained my question. I mean the following task. A spring pulls some mass. The mass here is inertial one but according Einstein will curve space-time. The question is in that whether this curvature explains the body inertia (resistance to the velocity change) or NOT?
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Dear Sirs,
I would like to find out more precisely whether the 2nd Newton law is valid or not in wide range of masses, accelerations, forces. Particulary I have a question whether the inertial property of body (inertial mass) is able to stop the body for small external forces or not. I have found in the Internet the fresh articles with tests of the 2nd Newton law for small accelerations (10^-10), small forces (10^-13) and SMALL masses (about 1 kg). The articles deal with the question of dark matter and MOND theory in astrophysics.
But I am interested in BIG masses. Could the test be carried out in planetary scale? Maybe for the Moon or asteroids? Or for masses like 1000 kg? Thank you very much for any references.
- When calculating ephemeris in the most accurate models of EPM and in some DE models, only miserable corrections are obtained from the PPN formalism. The Newtonian gravitation remains in the basement of celestial mechanics and of the GR. To my point of view, and stem from the fact, that geodetic lines in the presence of masses get bent, the Newton’s gravitation law suffers from a fundamental flaw due to violation of the inverse square law, underlying it. Let's try to go down from generalizations to specifics.
For example, discussing the modification of the law of Newton, I will argue that the mass is not an invariant, and the APPARENT gravitational mass depends on the distance to the observer Ma = M (1+ KR), where, for particular body, K = const. To verify the validity of the modified law, one will have to a) recalculate the masses of all celestial bodies in accordance with modified law, and b) get the Shapiro amendment, which will also depend on the (apparent) mass. As a result, using appropriate Shapiro delay values, we may get confirmation of the modified law.
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Dear Sirs,
1, 2, 3 laws of Newtons need closed system (net force is zero). How do we practically realize, create such closed system?
One example. Let us look at a body motion. One can say If the body velocity is constant, e.g. zero then no forces act to it. Is it true? I think no. According to the 1st Newton law the velocity constance is the CONSEQUENCE of F=0.
So are there precise ways to construct closed system? Or all physical theory is just a mean to generate a hypothesis which has more higher probability to be true then other random thought?
Dear Sir,
To the point how to construct.
Let us take component wise
Forces = Air frictional force if your relative velocity is high like 1m/s, frictional force from ground and touching surfaces, EM forces, Temperature gradients, Electrical Gradients, Gravitational forces.
Maintain constant Temperature that is generally room temperature- If temperature gradients exist then, source of it should be eliminated or considered in the system.
Use Glass material polished with talcum powder.
If any EM material Exist that is taken care by glass itself.
If high velocity Evacuate the chamber i.e. create vacuum.
Cover other surfaces also with talcum powder.
X & Z components are taken care by these.
Y component gravity is left that comes vey expensive.
So to eliminate gravity either use Archemedies Principle or do it simulation if real is not compulsory.
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Could you give references on mass measurement from the 3rd law (with different forces: gravitational, elastic, etc)? E.g. old articles by Saint-Venant.
Dear Preston,
Thank you very much for your papers
Anatoly
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How is it possible? What physics is behind it?
Dear Dr. Khripov:
Matching High permittivity with low dielectric loss
Both questions should be approached with significant careful. See, there are no rule and several exceptions.
If a homogeneous and single phase ceramic is the prototype material of this analysis, we should have grain and grain boundary regions, in which bulk or grain really interest.
The concept of High permittivity and low dielectric loss match when specific defects are further engineered in crystallographic way. In this sense, such defects are represented as sub-levels in gap.
The parameter dielectric loss is ascribed to electrical conduction; in fact a low level electric current is operational, with direct effect under aging of material.
The defect associated to development of high permittivity; in a broad sense are intrinsic and extrinsic defects that are not involved with long range moving carrier, electrons, but with charge density and electron-lattice kind coupling. Here, typically a new set of defect with distinct level in gap are formed.
On the possibility
Both phenomena are ascribed to distinct type of defect and its eventual interaction with crystalline lattice. In a gross manner, crystalline structure with more low symmetry, complex structures with great set of distinct crystallographic sites, ferroelectrics and materials that exhibits combinations of these characteristics is further candidate.
On the necessary physics
Materials Physics combined with Physical of Dielectrics and further characterization techniques, as Impedance spectroscopy or Dielectric spectroscopy.
In addition, as comment, major part of condition to attain the perfect response of material should involve advanced techniques of ceramic processing.
with best regards
Marcos Nobre
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Is there any body which is at rest but not in equilibrium?
There are two conditions for a body to be in equilibrium:
(i) Sum of forces acting on body= 0
(ii) Resultant torque = 0
If a body is in at rest, resultant force is zero. If a body is moving with uniform velocity, still the resultant force is zero. These bodies will be in equilibrium. Similarly a rotating ceiling fan is in equilibrium as net torque acting on it is zero.
Some physicists/teachers present the following two examples as bodies at rest but not in equilibrium:
1. Body at highest point when thrown upward against gravity.
2. Pendulum at its extremes.
But I'm not satisfied with these examples and the related explanations. I think that there is no body which is at rest but not in equilibrium. What do you say? Are the above examples correct as an answer to my question?
At rest means velocities vanish; at equilibrium means forces (and torques) vanish. Newton's second law implies that IF forces (and torques) vanish, velocities don't change; so if the velocities are zero they stay zero, if they're non-zero, they remain non-zero.
This is a homework assignment in elementary mechanics...
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I have data on a specific concept inventory (CI) from various cohorts. These cohorts can be categorised into group 1 with instruction type 1 and group 2 with instruction type 2. I know that the categorisation into these groups is reflected in the CI data, i.e. the performance is similar within the groups and different between the groups.
Would it be appropriate to perform a psychometric analysis on the combined data? Or should one treat both cases individually? In the latter case, the result could be that validity depends on the type of instruction.
What is the common practise? How did you choose your data?
Analytical approach, or analytical skill, which is characterized by each person, but this remedy is varying degrees vary according to the mental capacity of the person as well as the percentage of cognitive knowledge possessed by each person in addition to that cultural role in general; analysis is the fee to collect information and detail, analysis and dismantling; Resulting from the psychological reference, or other ... with thanks
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Example:
Our citrus industry can be related to the concept of ecosystem in Biology course. Here, I can explain that the citrus tree is a home to various insect and a substrate to some mosses; in which these insects and mosses may develop ecological relationship with one another.
If you can share me teaching materials or researches that relates science teaching with your local industry, that would be of great help to my study as well.
In our country, the pharmaceutical industry can be considered as a "true" chemical industry which has become reputable & succeeded in selling medicines to Europe as well as covering many local market demands.
While teaching industrial chemistry, I explain that most of the pharmaceutical industries "worldwide" are of the batch type so as our industries here. Students are required to understand, through examples, the characteristics of an industrial batch industry together with what items of equipment it will have & how these tools are operated.
A typical chemical industry must have a section for R&D "research & development" and our local pharmaceutical industries do have that from information I gathered from our graduates who work there. Therefore, students are required to know examples of the duties of the R&D section in an industry and the type of "applied" research that is carried out there.
Students of the industrial chemistry course ought to know the chemical names, the structural formulas, and the function of the most famous drugs such as Aspirin, Panadol, paracetamol , penicillin, amoxicillin…etc.
Even though it is an introductory course, students do not appreciate its value until they graduate & become fortunate enough to be employed in a chemical industry "pharmaceutical or other industries such as paints, plastics…etc.".
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I would like to know if it makes sense to perform a statistical analysis to evaluate how to improve the learning process and the teaching process during teaching. When teaching physics, chemistry or mathematics, does it have any utility to evaluate additional data to test scores and to the fulfillment of the program in class? How does the teaching process in the best teaching centers, the statistics that work for them, make sense, or is it simply a matter of quality in the knowledge and appropriate strategies? Greetings.
Doing a statistic analysis on the student answers to test questions can tell you what portions of the curriculum that the students are not grasping well. This can be used as a tool to strengthen those areas in you lessons.
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An atomic clock emits a nano-bullet that moves at a given speed through a vacuum pipe to another atomic clock at a given moment. The other atomic clock records the instant at which the bullet reaches and calculates the time of another atomic clock based on the known speed and distance. Sync the clock and repeat the back and forth comparisons. The data match shows that the clock time coincides.
With such a synchronous clock, can we measure the unidirectional speed of light unchanged?
To the original question: the two-way speed of light can clearly be measured with no issues: a light beam goes from source A to mirror B at distance L and then back to source A. A clock at A measures the time elapsed and always finds 2L/c, with c independent of reference frame.
So far, this is experiment, well confirmed in many different ways.
One-way speed of light always has some kind of problem, since we need to say when two distant clocks mark the same time. It turns out that it is a consistent convention to assume that clocks can be synchronised in such a way as to make the one-way speed of light constant.
However, to make contact with those who mentioned the Sagnac effect, this consistency only holds in *inertial* reference frames, not in rotating ones. In rotating reference frames, or other non-inertial frames, you generally cannot consistently synchronise clocks in such a way as to have a constant one-way speed of light.
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"I thought about quantum mechanics a hundred times more than general relativity, but I still don't understand," Einstein said.
Perhaps the most difficult to understand is the wave-particle duality, which may be because the understanding of it is only in the form of mathematics.In fact, no one can actually verify the wave-particle duality, because the experiment can't verify a single photon.
Electrons orbiting the nucleus of the cycle and the volatility of the particles there are closely linked, we can think of chemical bonds between atoms and atomic are fluctuating, at a certain moment because electronic is only a position on the orbit, and from the time a constantly changing position, the this kind of change has the regularity.When two atoms of electrons near each other, two atoms repel each other, and when electrons in an atom near the nucleus of another atom when they will attract each other, so that can form regularity of volatility.
Inner surface cracks in the double-slit experiment of atom has been in a regular wave conditions, when the particle is trying to through the gap, when near the atom will be fluctuations in the perforated of atomic bomb, a reflection of photonic and electronic electromagnetic ejection in such a state of regular fluctuations, as the accumulation of time and the number of regular interference fringes are formed.The smaller the momentum of a particle is, the larger the Angle of the ejection is, the greater the spacing of the stripes, the longer the wavelength is.
Electronic counter near the double slit to observe, emitting a large number of photon hits the aperture inner surface of atoms, and makes the surface atomic wave interference, can be seen as inhibits such a state of regular wave, the particles will no longer through double slit by regular reflection and ejection, which in turn has emerged two bright stripe.
This is why increasing gap width will not cause interference and diffraction, because of the emitted particles and gap edge contact and collision probability becomes a matter of fact interference and diffraction and crack width, crack of fluctuations, particle momentum, launch position and the Angle of aperture.
No there isn't. All this is understood and taught in physics courses, so it would be useful to actually study quantum mechanics, instead of trying to guess.
These lectures: http://www.feynmanlectures.caltech.edu/III_toc.html might be a good place to start.
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The general idea I have is, when we have photo ionised a molecule, vacancy will be created at the core and this vacancy could be filled by the electron in the outer shell (usually transition elements, which have unpaired electron), so we would have multiplet splitting. But why is this not considered Auger?
1. Is this not the same principle that happens during Auger spectroscopy?
2. It is reported in multiple papers that transition metals show multiplet. eg, NiO is reported to show multiplet, but one of the multiplet also overlaps with Ni3+. Is there a way to exactly differentiate it?
Multiplet splitting arises when an atom contains unpaired electrons (e.g. Cr(III), 3p63d3). When a core electron vacancy is created by photoionization, there can be coupling between the unpaired electron in the core with the unpaired electrons in the outer shell. This can create a number of final states, which will be seen in the photoelectron spectrum as a multi-peak "envelope".
[1] J.F. Moulder, W.F. Stickle, P.E. Sobol, K.D. Bomben, Handbook of X-ray Photoelectron Spectroscopy, Perkin-Elmer Corp, Eden Prairie, MN, 1992. [2] R.P. Gupta, S.K. Sen, Phys. Rev. B 12 (1975) 15. [3] A.P. Grosvenor, M.C. Biesinger, R.St.C. Smart, N.S. McIntrye, Surf. Sci. 600 (2006) 1771. [4] N.S. McIntyre, D.G. Zetaruk, Anal. Chem. 49 (1977) 1521. [5] M.C. Biesinger, C. Brown, J.R. Mycroft, R.D. Davidson, N.S. McIntyre, Surf. Interface Anal. 36 (2004) 1550. [6] A.P. Grosvenor, B.A. Kobe, M.C. Biesinger, N.S. McIntyre, Surf. Interface Anal. 36 (2004) 1564. [7] M.C. Biesinger, L.W.M. Lau, A.R. Gerson, R.St.C. Smart, Physical Chemistry Chemical Physics, 14 (2012) 2434. [8] F. de Groot, A. Kotani, Core Level Spectroscopy of Solids, CRC Press, Boca Raton, 2008. [9] M.C. Biesinger, L.W.M. Lau, A.R. Gerson, R.St.C. Smart, Appl. Surf. Sci. 257 (2010) 887. [10] M.C. Biesinger, B.P. Payne, A.P. Grosvenor, L.W.M. Lau, A.R. Gerson, R.St.C. Smart, Appl. Surf. Sci. 257 (2011) 2717. [11] M.C. Biesinger, B.P. Payne, L.W.M. Lau, A.R. Gerson, R.St.C. Smart, Surf. Interface Anal. 41 (2009) 324.
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The Bermuda Triangle is one of the amazing landmarks in the world And there are strange, interesting and horrible events in that area. Events such as the crash of planes, the sinking of ships, the collapse of the compass, and etc. Scientists express different ideas for these events Like hexagonal clouds, deep earthquakes, atmospheric disturbances, methane gas and etc. And each of these reasons justifies part of the events in that area . What really happens in this area ? Could this be the cause of the extraterrestrials? Is there another area like the Bermuda Triangle?
It is time for someone to do a serious study of these events. Not just one investigator, but many of various disciplines and specialties.
People have already solved the disappearance of dinosaurs, why not these phenomena?
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What is the possibility that I'll get a PhD job for research in String Theory and Particle Physics? I'm currently in my 3rd Year of Undergraduate Studies and have done research work in Photonics. Due to unavailability of faculty specialized in relativity, cosmology, particle physics etc., I chose to do research in Photonics. To manage my interests, I studied relativity, particle physics from online resources. What are the chances that I'll get a PhD job at institutes like Perimeter Institute of Theoretical Physics, Institute of Theoretical Physics, Stanford, Kavli IPMU etc.?
Before you start investigating textbooks and study programs in fields of science, you should seriously contemplate whether you want to invest your life and talents in these areas.
The Standard Model of Particle Physics were completed in the mid-1970's. Try to explore which new, experimentally verified, ideas have emerged in the field of theoretical particle physics since then. Likewise, string theory was invented in the late 1960's and superstring theory during 1970's. Try to find out what these theories have contributed to observed physics.
The recent discovery of gravitational waves have opened new ways to explore cosmology and astro(particle) physics. This will hopefully lead to new insights and increased activity, both observationally and theoretically.
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There are pedagogical tendencies to teach applied physics in engineering careers
Having graduated in engineering physics and also obtained a graduate certificate in teaching science, I think the subject is of interest for me.
I think linking with practice is essential for engineers. Go to the essential and never rush materials, listening to student and asking question. Providing clear practical demonstration with analogies.
Also this could help
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As a Brazilian Portuguese native speaker, I am teaching since the last 3 years Mathematics and Physics in German (I am currently at the level C1/C2) in the city of Berlin. What I have noticed so far: most of the fast learners did not feel the impact of my accent and in few times the lack of native language expressions to explain a certain topic from my side was quickly complemented by these students. They are the minority in all classes I have been teaching. However, the slow learners gave up very quickly and used as an excuse for it the fact of a small lack of my languages skills, even if some of them had already a history of deficiency in their learning processes. I would be interested in quantitative studies that compares the impact of a foreign language teacher teaching in the mother language of children. Is there something remarkable on it to pay attention?
Jair,
Science - Non Mother tongue teachers
The only barrier that may exist is students not being able to understand the teacher  because of the language linguistic difference. I have personally witness this and it can be frustrating to students who have difficulties reading and writing. Otherwise, the science classroom is no longer the science teacher lecturing in front of the class but utilizing the 5E Model, with interactive smart board games and experiments, and PhET simulations.
Robin Ruiz
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¿How to promote phenomenon based learning in a curriculum organized by disciplines?
I am inclined to say phenomenon based learning is good for physics teaching as it is a challenging subject and from my experience in other content areas, students are fascinated by new experiences and happenings. You have by nod here!
Best regards,
Debra
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All spectra I've been able to find are taken above 400 nm. This is probably due to the fact that a spectrograph + ICCD is needed to be able to do this.
I wonder instead if  the filter leaks more easily in the near IR; anyway it seems to me normal that you measure the highest intensity around the yellow because the detector has possbly the highest sensitivity in that range and the flame has actually a relevant yellow emission, even if lower compared with NIR
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Dear Colleagues,
I am looking for AER colleagues in Europe, i.e. researchers or others that are doing astronomy education research. I myself is an astronomy education researcher in Sweden and looking for possible connections and contacts in, firstly, Europe, but also elsewhere.
I, together with a colleague of mine from Brasil, am trying to build a network to get a possible overview of the activities and efforts that have been done and are being done in Europe (thesis, articles, book, presentations, etc.). We are involved in an ambitious project to creating a world wide network of AER persons.
If you are a astronomy education researcher and feel that such network could be important and useful for you, please contact me via ResearchGate or email: urban.eriksson (at) fysik.lu.se.
Also, feel free to forward this information to any colleague of yours that might  be interested in such network.
Many thanks!
Urban
------------------------------
Urban Eriksson, Ph.D
Dr. Urban Eriksson Reader in Physics and Astronomy Education Research (PAER)
Assoc. Professor in physics with specialization in Physics Education Research Director for the National Resource Center for Physics Education
Chair for the IAU working group for Astronomy Education Research and Methods
Lund University  |  Faculty of Science  |  Department of Physics Box 118, SE 221 00 Lund, Sweden  |  Visiting address: Sölvegatan 14 urban.eriksson@fysik.lu.se  |  Mobile/WhatsApp: +46 73-059 39 62‬ www.lunduniversity.lu.se  |  www.fysik.org https://www.researchgate.net/profile/Urban_Eriksson
Dear Urban,
as mentioned above, this is very good idea to have such a kind of network!
If you need someone from Czech Republic, let me know. I am not for full time job a astronomy education researcher, but astronomy education as general is one of my area of interest.
To contact me, please, use ResearchGate or email kehar@kmt.zcu.cz
Best Regards
Ota Kehar
Faculty of Education
University of West Bohemia in Pilsen
Czech Republic
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The Schrodinger experiment (intended to illustrate what he thought was the implausibility of a half-live half-dead cat state function, but now taken seriously by many) is modified to examine the question of whether physical processes collapse the wave function, or whether consciousness is required as I understand von Neumann suspected.
The AI (artificial intelligence) is not assumed to be conscious, just a sophisticated but deterministic program, or expert system, with motors attached robot-like. We assume from quantum mechanics calculations that the room contains a state function which is a 50-50 live-cat, dead-cat. When we open the room we expect to find one of the following:
• Live cat, with AI having recorded an observation of opening the smaller box and finding a live cat.
• Dead cat, with AI having recorded an observation of opening the smaller box and finding a dead cat.
There is nothing to collapse the wavefunction until you and I open the box, according to von Neumann. As I understand him. The AI is a physical process, just like the cat's internal biological processes are physical, and if the cat itself doesn't collapse the wave function, neither can the AI.
However, notice that the AI has the same subjective experiences that we do. There is no cross-state mixing between the AI and the cat. The AI which found the live cat never mixes with the dead cat state, and vice versa.
There, in an interview with the AI, it will insist that it never found any contradiction to the notion that it collapsed the wave function, even though our mathematics informs us otherwise.
Charles Francis,
I am sorry for any provocative or challenging statements – or perhaps not! My experience is that being provocative (within limits of course) often brings out engaged and honest responses that could provide a deeper understanding even if not ending in full agreement.
I have always been careful to define in each case what I mean with quantum, classical, frequentist, Bayesian etc. probability before concluding anything while you always refer to probability as a god-given concept always applicable.
At the end of the day, we could reduce measured results indefinitely perfecting our subjective information of the experiment using whatever statistics available, but still not knowing, when sending the next silver atom through the S-G apparatus, on which sceen the atom will be collected.
QM is an axiomatic deductive theory that has a unique mathematical formulation. One of the axioms concerns the wavefunction and defines a probability concept that is unlike any classical probability version.
The physical interpretation is a separate process from the mathematical formulation. In e.g. the Bohr interpretation the experimental apparatus is classical and the task is to equate a quantum measurement with classical end results, after the experiment is finished and documented.
The novel development of quantum cryptology, quantum computing, interferometry, teleportation etc. show that the notion of measurement evolves in subtle but fundamental ways imparting exacting references to concepts like properties carried by quantum particles, the meaning of localization, or the violation of Bell’s inequality, and the fundamental assumption of realism, i.e. can reality and information be separated from each other.
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Many QM text books say that because one can obtain interference patterns even when only one particle passes through the equipment at a time, this is proof of wave-like behaviour and that each particle must therefore pass through both slits and interfere with itself.
The brighter physics undergraduate then says ah yes, but sound or water waves also show interference with twin slits.
In the case of sound waves when viewed at the molecular level, they are just gas particles that collide, and there is no need to assume that a molecule passes through both slits to interfere with itself. Particularly if pressure is reduced so at any one time only one collision takes place at a point in time. (the equivalent of one photon passing through the experiment at a time).
The explanation has to be able to define the logic that leads to the assertion that in the photon case, the particle passes through both slits to interfere with itself, whereas in the sonic case it does not.
To @Paul and to the other users:
You cannot explain that one photon goes through both slits, because we don't know this. We don't know what is the wave-function. The standard quantum mechanics tells us only what we can get if we measure. All the rest is speculations.
What you can tell the students is that in order to get interference, both slits should be open. If only one slit is open we don't get interference. Therefore, whatever we can infer is that something passes through both slits, and in consequence we get interference. But what passes and through which slit, we don't know.
This is exactly the domain of research named fundaments of QM. We try to investigate these issues but for the moment we don't have answers. We don't know what we have in our apparatus before we measure.
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I work with supervised training in Brazil, especially with physics formation teachers' students. I want understand how occur this moment in your country: when its happens (starting in the middle of the course like here), who supervised (at school and from university) and how happen this supervision. If you can list some papers, I thank you.
Practice teaching of Education students in the Philippines is usually done on the first semester of the fourth (and final) year of their bachelor's degree program. Usually, there are two training / practice teaching supervisors assigned for each practice teacher: one from the sending school and another from the host school. Some relevant papers are provided in the links below:
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especially for Physics teaching
si por supuesto le recomiendo el sitio de la Universidad TEcnológica de Monterrey México donde utilizan simuladores también las universidades marítimas tienen  simuladores para la enseñanza de tripulaciones en escenarios difíciles.
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The majority of the undergraduate physics students are familiar with length contraction, time dilation, relativistic mass and energy, relativistic electric and magnetic fields. But, they have no idea about relativistic temperature, heat, and the form of the thermodynamics laws in special theory of relativity,
We have recently also come to the topic of relativistic thermodynamics. It is surprising that it is not included in the basic courses. It is not difficult to combine these two approaches and one obtains interesting consequences. It is interesting that one intensive variable, pressure, is invariant, while temperature is contracting.
On the other hand, it is clear that entropy must be invariant, since it is equal to log W(n) and also from the second law of TD.
Going to statistical mechanics, it is clear that Mawell-Boltzman distribution cannot be true, because it would allow particles with v > c. Thus, a straightforward generalization is Maxwell-Jüttner distribution, still equal to exp(-E/kT), but with relativistic energy.
These points are important enough to be discussed in some courses on advanced thermodynamics or relativity courses.
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Given the difficulty in measuring socially just behaviours, I am hoping to find a tool to specifically measure if an intervention might increase education students willingness to engage in social issues. I am aware of questionnaires used in both psychology and social work, but have not seen anything specifically for tailored to education.
Thanks
Bonjour Dr Lee!  Social Justice Through Teaching Practices and Activities (Brian O’Sullivan, Reva Joshee & John MacDonald, 2005). https://www.oise.utoronto.ca/cld/UserFiles/File/Social%20Justice%20Through%20Teaching%20Practices%20and%20Activities.pdf  - It may be dated. Best regards: James
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I'm looking for program/model that effectively improves physical abilities/skills of elementary and high school students, and if possible free one:-). I'm aware of SPARK, which is a commercial program, but I would like to see something that is available to everybody.
Thanks.
Here are some weblink(s) or pdf files that I searched on the internet that might assist with your research in physical education.
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Teaching based intuition/graphical/applications or teaching based demonstrations/technical language/excercises?
I think no single teaching method/technique would help you. Actually, I tried both methods with one of my colleagues who has difficulties in understanding statistics and I failed. To me, graphical method works fine;I can cover the black areas and move on. However, this technique does not work with my colleagues.
In general, I may share some points of my own experience:
• Don't assume that students understand anything about statistics, even if they had a basic course or something like that before. In my experience, most of the students forget the basic rules of statistics all the time. So, it is better to quickly review the basics before presenting any new idea.
• Let students explain the same concepts you have just said. In other words, don't assume that students understand what you are saying. I always see students understanding a completely different thing than what I say.
• Let students think of the problem and the solution before you present the rule. This will save your time repeating the same idea over and over again. Give students one moment of silence to think. Let them infer by themselves; or at least try.
• Repeat or re-display the same concept with different methods. As I said, no one technique with serve all students.
This is my own experience. Please search for scientific papers that may give you more trusted results.
Best Regards,
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Models are very important as they enable aspects of the system, i.e., objects, events, or ideas which are either complex, or on a different scale to that which is normally perceived, or abstract to become either visible or more readily visible.
Models are also very important in scientific research in formulating hypotheses to be tested and describing scientific phenomena.
Recently, the need of a theory of model-based teaching and learning (MBTL) came out due to the cognition of the importance of models in physics education and research.
One of the challenges up to now is that there is no coherent theory that outlines the cognitive processes involved in model-based learning and even there are no any coherent theories of how model-based teaching should be approached.
Ausubel is a good source for that piece in regard to previewing ("(priming" in behavior theory, "activation" in neuroscience).  Previewing can be a stage/tool in the input stage of a system (increase in receptivity/relevance to curriculum).  A point here: as much as possible make the analysis and discussion generic, and separate diligently the topics of instruction (process and process tools) vs. curriculum (content).  Generic language may seem abstract at first but exemplary specific content can be used in your subject area.  Generics apply to all teachers and content at every level.  Be clear at the outset about the context of your inquiry:  instruction or curriculum, but not both.  Instruction theory applies to any and all processes used to convey curriculum content, but curriculum theory applies only to content understanding.
A good second-order Cybernetics article is:
Second-Order Economics as an Example of Second-Order Cybernetics Cybernetics and Human Knowing. Vol. 18, nos. 3-4, Cybernetics and Human Knowing. Vol. 18, nos. 3-4, pp?
The "First principles" thread is also very good in education:
Merrill, M. D. (2002). First principles of instruction. Educational Technology Research and Development, 50(3), 43-59.
Merrill, M.D. (1994). Instructional design theory. Englewood Cliffs: Educational Technology Publica- tions.
Reigeluth, C.M. (1999). The elaboration theory: guidance for scope and sequence decisions. In C.M. Reigeluth (Ed.), Instructional design theories and models: A new paradigm of instructional theory (Vol. II) (pp. 425–453). Mahwah, NJ: Lawrence Erlbaum Associates.
Typical courses on "Learning," "education" and "teaching" deal with curriculum and almost never on "instruction" per se.  This confusion leads to thinking that each curriculum area has its own way of teaching, but the deep structure of principles are the same.  Once one understands the deep structure framework then any curriculum can be hung on that framework.  A kindergarten teacher and a teaching neurosurgeon us the same cybernetic framework for instruction.
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Which could be the best examples to explain Inertial Reference Frame in the High School?
The best way to begin with, is to tell people what is a non-inertial frame. For illustrating this, one can place a piece of chalk on a gyroscope, then make the gyroscope to rotate. The chalk would fly off the gyroscope surface, although no force acts on it.
The chalk tends to maintain its state at rest with respect to the lab, but with respect to the gyroscope surface it has a velocity that changes direction - wherefrom there appears an acceleration with respect to the gyroscope, as if a force acts on the chalk.
This is a so-called pseudo-force, i.e. a force that appears without the action of another body or field on the chalk. Coordinate frames in which act such forces are named non-inertial, because a body left free, not attached tightly to the frame, doesn't preserve its state of motion - state of rest in our case.
To the difference, a frame in which a free body preserves its state of movement in absence of action of bodies or fields, i.e. there are no pseudo-forces, is named an inertial frame.
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I am interested in the teaching modality for high school physics with minimal or no ICT capability.  How physics concepts are brought to the learner and what challenges were commonl;y met.
Here, teaching Physics is challenging because our high school students find it hard to relate to concepts in Physics.  ICT helps to connect the concepts to the minds of students with appropriate examples.  But without ICT, it requires all the abilities of the teacher to describe and explain so that students can grasp the concepts.  (We even have students who say that Physics is boring, just because they aren't able to understand it.  Actually Physics is interesting.)
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I have some feedback from a referee at Physics Education (PED) on the draft paper linked below, Leading Clocks Lag - A Pedagogical Memory Aide.
The reviewer comments (below, 1 referee for apparently preliminary review) can be summarized as:
1. Liked the heuristic "leading clocks lag."
2. Didn't know about and enjoyed reading the de Broglie wavelength derivation.
3. Eliminate well known (textbook-ish) derivations.
4. Include some comments on use of the material in student discussions.
Item #4 I cannot do myself. Do you teach this level of physics, or are you involved with a student physics club, and find the idea sufficiently interesting to try with some students? I would of course be happy to accept a co-author who could help meet the referee's requirements.
Yours,
Robert
REFEREE REPORT(S):
Referee: 1