Classical Definition and 1000 Threads

1. Homework Statement Question attached. I am looking at the second line limit ##\beta (h/2\pi) \omega << 1 ## 2. Homework Equations above 3. The Attempt at a Solution Q1)In general in an expansion we neglect terms when we expand about some the variable taking small values of the...

Good morning. The question of the "continuous" or "discrete" nature of the universe is the subject of diatribe among the greatest physicists in the world. I would like to discuss the same topic, but asking a question about the aspect of continuum in classical mechanics. The use of mathematical...

I am looking for an undergraduate textbook on Classical Mechanics that includes Hamiltonian and Lagrangian formulations. One reason for this is that I am interested in quantization and second quantization. It should include treatment of harmonics oscillators. Thanks!

Homework Statement Consider 2 balls A,B on the same line . and they are connected to a third one G with a rope L. AG, AB. now the system monves in the effect of the mass of G and its projection to the line AB is in the middle. No friction. mass of A=mass of B=m and mass of G=2m .FInd the time...

I'm reading "Division Algebras and Quantum Theory" by John Baez https://arxiv.org/abs/1101.5690 In the last paragraph of section 5 (Applications) he says the following "SU(2) is not the only compact Lie group with the property that all its irreducible continuous unitary representations on...

It is the resolution given by my thermal interpretation, and this resolution is valid (independent of the thermal interpretation) even without being accepted. Bell assumes that measurement outcomes follow strictly and with infinite precision Born's rule for a von Neumann measurement. But the...

Hi all, I recently learned the concept of Maxwell's speed distribution and became interested in how to use similar momentum distributions to study the probabilistic motion of a classical free particle. I have done some of my own reading on probabilities and distributions (no formal lessons yet)...

I am self studying Classical Mechanics and I am a bit confused about this. After reading Kleppner Kolenkow Mechanics can I read Symon's Mechanics or do I need to read anything in between like Fowels or Marion&Thornton? I already studied the Maths portion upto Multivariable Calculus,Real...

I need a book with exercises, to try to excel my next classical mechanics, I really to get a good grade. Thank you very much!

I’m felling demotivated because I had a bad grade, I don’t know how I got such kind of grade. However, I’m looking to get a very good grade in the next test, that will count 100%. I’m in the first year of physics, what advices do you have on how to study(CM), which exercises? What books should...

Hi at everyone, why on wiki there is written: " According to modern understanding, the electron is a point particle with a point charge and no spatial extent. Attempts to model the electron as a non-point particle are considered ill-conceived and counter-pedagogic " I don't understand this...

Mentor's note: this thread has been forked from https://www.physicsforums.com/threads/why-the-photon-has-no-mass.899792/#post-5912751 But momentum = mass x velocity so that part of the equation is E2 = c.(mv) If the mass is zero then that formulation also yields zero energy (which we know is...

Homework Statement Referring to the attached diagram, the object ABCD is kept in an isolated system where it is under no external influence of any kind. A· An instantaneous force F acts along the edge BC of the block ABCD, where M is its mass, with its center of mass located at O...

We obtain equations of motion by solving the Euler-Lagrange equations; along this path the action ##S## is an extremum. We are usually interested in the path ##x(t)## (in one dimension) connecting ##x(0)=x_0## and ##x(T)=x_1##. But does the numerical (extremal) value of the resulting action have...

Hi guys, I am having an issue with what my lecture is saying in these slides, I have attched my slides below. Here is my issue. I am very confused by the ##E<\Delta ## Beacuse I can't see how this has any momentum as it would produce an imagery number. And ye say that ##E<\Delta ## cannot...

is there a way for me see EVERY solution from goldstein's book? i already have some solutions, but not every one

A question I've had about the black body problem and classical physics in general has to do with the conservation of energy. One of the first things you can derive in classical mechanics is that for a conservative force the total energy of the system doesn't change. However, one of the typical...

Homework Statement (x^2 + y^2)/a^2 + z^2/c^2 = 1 Homework Equations [/B] The Attempt at a Solution the answer is : b(θ) = R / (f^2 * tan^2(θ/2) + 1)^0.5 I can't understand how to calculate this. My attempt : (x^2 + y^2)/a^2 + z^2/c^2 = 1 from this. b^2 + z^2/f^2 = a^2 , f = c/a, z =...

how is md^2r/dt^2 . dr/dt = d/dt (1/2 m (dr/dt)^2 ) Thank You

Homework Statement [/B] In this example, I know that I can define the horizontal contribution of kinetic energy to the ball as ##\frac{1}{2}m(\dot{x} + \dot{X})^2##. In the following example, Mass ##M_{x1}##'s horizontal contribution to KE is defined as ##\frac{1}{2}m(\dot{X} -...

Homework Statement I'm having some issues understanding a number of concepts in this section here. I attached the corresponding figure at the end of the post for reference. Issue 1) 1st of all, I understand that a Hamiltonian can be written as such $$H = T_2 - T_0 + U$$ whereby ##T_2##...

Homework Statement I have the answer for part a, which is: $$\theta '' + \frac{a}{r} \cos \theta + \frac{g}{r} \sin \theta$$ My issue lies with getting the following equation of motion for part b, $$\theta '' + \frac{g}{r} \cos \alpha \sin \theta = 0$$ Homework EquationsThe Attempt at a...

Homework Statement The skier is skiing without friction down the mountain, being all the time in a specified plane. The skier's altitude y(x) is described as a certain defined function of parameter x, which stands for the horizontal distance of the skier from the initial position. The skier is...

Homework Statement Homework EquationsThe Attempt at a Solution I have done part a, I have no idea on part b, here is my attempt,

I have no prior experience in physics, but I am a math undergrad so I know calculus, differential equations, linear algebra and stuff like that. So I'm ready to move from the conceptual "bedtime story physics" to stuff with real mathematical rigor. So, what is classical mechanics all about...

I came to know that time evolution in classical mechanics is highly non linear. Is there any case that it become linear?

In classical mechanics and EM, the energy carried by a wave is the amplitude squared. In QM the (complex) amplitude squared of the position-space wave function is the position probability density. Do physicists regard this as anything more than just an interesting coincidence? Has anybody...

The moon orbits Earth at a radius of 3.84E8 m. To do so as a classical particle, its wavelength should be small. But small relative to what? Being a rough measure of the region where it is confined, the orbit radius is certainly a relevant dimension against which to compare the wavelength...

Homework Statement Show that the classical path satisfying ##\bar{x}(t_a) = x_a##, ##\bar{x}(t_b) = x_b## and ##T = t_b-t_a## is $$\bar{x}(t) = x_b\frac{\sin\omega (t-t_a)}{\sin\omega T} + x_a\frac{\sin\omega (t_b-t)}{\sin\omega T}$$ Homework Equations The Lagrangian: ##L =...

We laymen and newbies are taught the Schrodinger equation was deterministic. So we tend to picture it’s like a classical thing.. some forever thinking it that way where the idea is etched deep in the mind. Yet when we are home with the idea it is deterministic (that is.. when not measured)...

I'm sophomore in physics looking for best free books for classical mechanics and for vibrations and waves. Anyone with references pleaseThank you

What are the very good books for practicing variety of and a lot of problems covering every concepts (analytical ,mathematically interpreted and intuitive )related to the topic .Books can be of physics or applied physics bcoz I have seen a book on applied mechanics like Housner-houdson .

I have been studying classical mechanics for a while from Goldstein book and can't go ahead of the following derivation. I understand the method of Lagrange's multipliers for getting extrima of a function subjected to equality constraints but can't understand it's relevance here because in that...

Hello, It is considered that the time is continuous in classical physics, but it sounds paradoxal to me, let me explain. Let a particle inside a galilean frame of reference. This particle can only be measured either at rest, either in motion, but never simultaneously at rest and in motion...

This is an interesting question that popped through my mind. Some of us should know what is meant by „gauge transformations”, „gauge invariance/symmetry” and are used to seeing these terms whenever lectures on quantum field theory are read. But the electromagnetic field in vacuum (described in a...

Hello PF, I am taking classical mechanics this fall and I am horrified. I am just not sure if I have the mathematics background for the class. I am still finishing differential equations (about half way done) and I am almost done with calculus 3. The pre-requisite for the class is DE...

Homework Statement Homework EquationsThe Attempt at a Solution My difficulty is : If electron with orbital motion is taken as a dipole, then since the magnetic field is uniform, the net force due to magnetic field is 0. But, in eqn. 6.6, while calculating force acting on it , e is taken as a...

According to classical electromagnetic theory,for acceleration a particle must not only change its direction but it should also increase its speed. But Maxwell said that a particle accelerates then it radiates energy.(this is with reference to Rutherford model). But actually the particle is not...

I'm working on semiconductor physics and cyclotrons. There's an article that I am trying to understand, but am having difficulties matching with experiment. I asked a question on an electronics site, but apparently the physics is too advanced. The relativity article which sparked my interest...

Hello! I would like to know what are some good resources for studying classical and quantum Yang-Mills(non-abelian QFT) such as textbooks, lecture notes etc. Thanks in advance!

Hello all. This is my first post. I am very passionate with physics even if i did not study them at university. I studied administation and another degree in economics and politics. However, i love physics so much and i decided to learn more about this subject. So, i searched MIT's undegraduate...

Hi everyone, I have a question that, when came to me, sounded a bit silly to me as well, but then I realized, I myself maybe don't understand the logic behind this 100%, so why not discussing with you about it. So my question is the following. Usually we are used to do quantum field theory...

In classical mechanics, if a system consisting of one particle suddenly became two particles, the entropy of the system would increase because the number of spatial degrees of freedom would double. But, in QM, I believe, when one particle decays into two particles, the two new particles would be...

It seems that most recently published analysis textbooks are written from a more abstract perspective, e.g., dealing with functions on general metric spaces or with spaces of functions. However, often solving a problem requires some "get your hands dirty" classical or "hard" analysis -- for...

Hello! How do I find how much energy does electron radiate during one revolution if the energy radiation rate is given by Larmor Formula: dE /dt = [(− 2/3)* e2* a2]/ c3. Should I use the chain rule? At the moment I only want a hint how to solve this. With best regards

1. In Classical Hamiltonian, it's equal to the kinetic energy plus potential energy.. but I read it that for a free particle, it doesn't even depend on position.. i thought the potential energy depends on position. If it doesn't depend on position, what does it depend on? 2. Since the...

Homework Statement A friend and I are going through Vladimir Arnold's Mathematical Methods of Classical Mechanics, but I think my lack of a background in pure math / proofs is seriously hampering my ability to do any of the problems in the first chapter. For example: PROBLEM. Show that if a...

Fusion is, in most cases (stars, etc.), considered probabilistic. The Gamow-Sommerfeld factor is used to calculate the probability that two colliding nuclei will undergo fusion, considering the fact that the particles have a chance of fusing by quantum tunneling. However, one can calculate an...

The Hamiltonian in classical mechanics is not always equal to the total energy of the system. I believe this is only true if there is only a potential field and no vector potential. However, in quantum mechanics for a particle in an EM field, even if a vector potential is used the energy...

Is classical physics more than just the quantum physics of a large number of particles and quanta? Thanks for your thoughts.