Classical Definition and 1000 Threads

Hi, I was wondering if someone could point me to a textbook or easy to read paper (or website) that briefly describes/proves the differences here. What I mean is if I do classical (continuous energies) statistical mechanics where my initial state is a volume (greater than or equal to h-bar)...

In quantum mechanics one can convert the wave function of one variable into the wave function of its conjugate pair (e.g., momentum and coordinate) using a Fourier transform. Now consider the classical case. Suppose there is a particle in a potential well with insufficient energy to escape...

Homework Statement I have a problem regarding to lagrangian. If L is a Lagrangian for a system of n degrees of freedom satisfying Lagrange's equations, show by direct substitution that L' = L + \frac{d F(q_1,...,q_n,t)}{d t} also satisfies Lagrange's equations where F is any ARBITRARY BUT...

i learned that we have to consider quantum effects at low temperatures and classical effects at high temperatures but i do not the physics behind it can anyone explain it for me? thanks in advance :)

i need someone to explain me the aberration of light , i tried to read i from my book its a bit more complicated than i thought i mean when we move the microcope we make a tilt what do you mean by that? all in all i didnt understand this concept and i need a really clear explanation especially...

This has been nagging me in the background of my mind for many years and I've decided to get it sorted. I note that I'm not sure if this should be in the classical or quantum forum. I have heard it mentioned by many and often when referring to the inherent uncertainty when measuring...

The gold standard for generating random numbers is the quantum effect of nuclear decay -- particles and photons being emitted from the atomic nucleus -- and unless you are one of those Hidden Variables types this is really random. The silver standard is thermal noise. There is a nice article in...

When we setup the Schrodinger equation for the hydrogen atom we use the classical electric potential. It seems that we would need a new potential instead of mixing QM and classical. Is this just a very good approximation or is there something subtle.

Trying to get the idea behind this, but it's kind of new thinking all this rotational dynamics. The classical example of conservation of angular momentum is when a ballerina pulls in her arms as she spins to spin faster. The angular momentum theorem tells us: I1*α1 = I2*α2 So as she decreases...

I've just seen this article: http://www.newscientist.com/article/dn21235-entangled-diamonds-blur-quantumclassical-divide.html Was published yesterday (or today?). Makes interesting news.

I've heard it said that 'we don't really understand turbulence', and that it is one of the biggest outstanding problems in classical physics right now. (Or at least Feynman thought so back in his day) But what is there to understand about turbulence and why don't we understand it? I thought...

I do not know but I do not know if Ampers law is valid for short conductors passing through a loop. I did integrate and my integral was different from the expected I*U. The law seems to be valid only when long conductors pass through a loop but not short ones. Can anyone explain what am missing?

I like your explanation, and I agree. However, why does it not work for the case of gravity? To be more specific, I'm talking about the mainstream classical justification for the equivalence principle as it applies to active gravitational mass. Let me give an analogy that applies to the OPs...

Hello. I'm trying to understand why, in terms of Maxwell's Equations, the ratio of the number of turns in a transformer converts an input voltage to an output voltage. EE explanations only seem to go as deep as this article: http://en.wikipedia.org/wiki/Transformer#Basic_principles They state...

I'm learning mechanics right now via an extension course. In the absence of an "on-demand" teacher I've found multiple textbooks and online resources to be useful. When I studied calculus, Paul's online calculus notes (http://tutorial.math.lamar.edu/Classes/CalcII/CalcII.aspx) were a great...

Homework Statement A mass, m, is attached to a support by a spring with spring constant, k. The mass is hanging down from the spring, so there is a gravitational force on the mass as well. Neglect any resistive or frictional force. The support is then oscillated with an amplitude of A and...

Hey guys, First time posting. I was thinking of starting an extra credit paper for my Physics 1A course, and was wondering if anybody could think of any noteworthy and recent applications of classical mechanics that I could do some research on. I was thinking of maybe pursuing dark matter as...

Hi, I'm a bit confused wit the concept Configuration Space. First, the professor defined generalised coordinates as such: U got a system of n particles, each particle has 3 coordinates(x,y,z), so u got 3n degrees of freedom. If the system has k holonomic constraints, u got 3n-k degrees...

This is really simple but I can't figure it out. I was on a bus when I thought of this: Say I'm sitting in the back of a bus which is traveling on a flat surface, and accelerating with a constant acceleration (forward). Now I get up from my seat in the back and make my way to the front of the...

This is problem 9.2 in solid state physics by Ibach and Luth. Homework Statement Using the stationary Boltzmann equation, show that the mobility of the charged particles in a classical gas is given by \mu = \frac{e \langle v^2 \tau(\mathbf{k}) \rangle}{m \langle v^2 \rangle}...

Has there been work done exploring the possible connection between chaotic systems and quantum mechanics? Chaos basically tells us that an infinitesimal change in initial conditions, given enough time, will lead to complete different solutions - another way of stating that is over enough...

Homework Statement Set up the equations of motion for the system shown in Fig. 4.16. The relaxed lengths of the two springs are l1, l2 . Separate the problem into two problems, one involving the motion of the center of mass, and the other involving the "internal motion" described by the two...

How the Deutsch's algorithm outperforms a classical algorithm? In both algorithms we need two particles (two bits and two qubits). In the quantum case the two qubits are processed by the FCNOT gate simultaneously but it's equivalent to two classical "black boxes". So if we take two classical...

I am interested to know everyones favourite piece of classical music! I am a hopeless musician, but i love listening to classical music whilst i do mathematics, its like transcending to another plane of existence.

First of all, I haven't the slightest idea how a quantum computer actually works but I understand that it is theoretically possible to make them and they could, in theory, be used to compute things that a classical computer would take too long to compute. (i.e. large combinatorial problems like...

in the literature, people are talking about 'quantum systems without a classical limit' could anyone give me an example?

Will taking a course is continuum mechanics give me the same background as in classical mechanics or would I need to take both separately? Can anyone explain the difference if there is one between classical mechanic vs continuum mechanics in simple nontechnical terms.

Im pretty good at Mechanics but I need a "feel good" book which can complement and help me strengthen my concepts of mechanics very well. I like thorough explanations so I can be conceptually good and in a position to attempt most questions. Also needs to have good worked examples. Please let me...

Homework Statement Consider the bead threaded on a cicular hoop of example 7.6 (pg 260), working in a frame that rotates with the hoop. find the equation of motion of the bead, and check that your result agrees with eq 7. 69. Using a free body diagram explain the result 7.71 for...

Not sure whether to put this in the QM forum or the classical forum, you'll see why-- I was thinking about the http://grad.physics.sunysb.edu/~amarch/ version of the double slit experiment, in which the information about which slit the particle went through is obtained in a somewhat unusual...

Hello PF group. Long time reader, first time poster. Can someone please make some recommendations for a good classical physics textbook, particularity suited to self-learning classical physics? I'd also like the recommendation to not be calculus based. My preferences are for something...

Homework Statement A particle of mass "m" whose motion start with downard velocity V0 in a constant gravitational field. The drag force is quadratic and proportional to kmv2. What is the distance s through which the particle falls in accelerating from v0 to v1. Give your expression for s in...

Homework Statement show that y=ex-vt)7/8 Homework Equations d2y/dt2= d2y/dx2 The Attempt at a Solution i don't understand how they solve this. in the book they have dy/dt=ezdz/dt=-7/8vez(x-vt)-1/8 I thought it would be -7/8veex-vt)7/8 not sure what they did any. thanks

After studying both areas of classical and quantum physics in some depth, I've reached the conclusion classical physics is more elegant and ingenious than quantum physics. Newton's law of gravitation is elegant because its sheer simplicity allows us to map the trajectory of satellites...

When does quantum "take over" classical? There's seems to be a lot of information about how relativity "takes over" classical mechanics when certain speeds are reached, like at a certain % of speed of light, etc. I haven't found much information regarding when quantum mechanics takes over for...

Can someone explain to me how an atom can absorb the energy of an incident photon without being ionised? What is the photon energy transformed into and how is it transferred between the photon and the atom (what part of the atom absorbs the energy?). I can't find anything helpful online - the...

According to the usual way of applying determinism in physics:- If we know all the intitial conditions of a closed system at time t0, we can fully specify the the system at a time t1>t0. This seems natural and obvious within classical physics, but is it really true? I have never heard of a...

Suppose I solve the Schrodinger wave equation described in terms of position (as opposed to momentum based description), it gives me the wave function from which I can determine the probability distribution function (pdf) for position with a parameter as time. I view it as the following, the...

Hi! I am a very mathematically-oriented physicist. Since I never plan in making contact with "dirty" mechanics like robotics, structural problems or force diagrams, I want a book that prepares me for the mathematical/theoretical foundations of mechanics so that I can transition more smoothly to...

The principle of least action applicable in an uniform field can be obtained as follows: Particle A \vec{a}_A = \vec{a}_A \int \vec{a}_A \cdot d\vec{r}_A = \int \vec{a}_A \cdot d\vec{r}_A \int \vec{a}_A \cdot d\vec{r}_A = \Delta \; {\textstyle \frac{1}{2}}\vec{v}_A^2 \int \vec{a}_A...

So I want to get all the Equations that describe classical Physics together because I think it would make a kick *** poster. Tell me if I am missing anything or if you don't think one should be on here. [PLAIN]http://img694.imageshack.us/img694/9646/classicalequations.gif

I'm working on a project for a space habitat, and I want to have the math to back it up. Sorry if some of these seem obvious or too simple, but I'm here to learn. By the way this is not homework, it's just something I do in my spare time. And if you have the links where I can learn more about...

hey, This question is about a system where one mass is on an incline and another hanging of it. They are connected with a rope.. Its a classical mass rope mass problem. My reasoning was that since the mass hanging of the cliff is pulling on the rope with a force of mg, the rope will be...

Terminal Velocity In Glycerin 2.10 in "Classical Mechanics" Homework Statement For a steel ball bearing (diameter 2mm and density 7.8g/cm3) dropped in glycerin (density 1.3g/cm3 and viscosity 12 N s/m2 at STP) the dominant drag force is linear drag given by flin = 3*pi*n*D*v where D is the...

Homework Statement This is a fairly general problem that came up while trying to model a system. Given a rotating disk and an inertially fixed object, how is the fictional coriolis force handled? For example, if there is a dot on the ground below a sheet of transparent plastic rotating at...

Homework Statement "A passenger (mass m) initially at rest steps out of an airplane. Assume down is the positive x-axis and put the origin at the airplane. Assume the air resistance force is linear in the velocity so F(air)= -mbv. Find the distance D he has fallen when his velocity is...

I have spent lot of time trying to understand scattering from Goldstein but in vain. The general equation of an orbit is, 1/r = K[1 + e*cos(θ - θ')] where e=eccentricity I refer to a sentence in goldstein which says, if θ'=pi then θ = 0 corresponds to the periapsis. What is θ'...

Homework Statement A particle has a velocity u = -V0 i + V0 j and position (d,0) at t=0. At any time t its position in polar coordinates is (r,theta) and velocity V = V0 cos theta i + (V0-V0sin theta) j. At t =t, angular velocity of the particle at the origin will be -----------------...

Hi, I'm currently a physics major attempting to earn my bachelor's degree. I was just told by the tiny physics department at my school that they won't be offering the classical mechanics course that I need in order to graduate before that fateful date, they suggested that I add an additional...

reading this http://uk.arxiv.org/abs/1004.2529 about supposed parallels between the mathematical structure of probability in QM and some problems in economics question is that are there really any violations of classical probability theory, such as Pr(A) > Pr(A \cup B) in QM? The supposed...