Griffiths Definition and 227 Threads

I am self-studying quantum mechanics from Griffiths' textbook and some other sources. I have come across this derivation shown in the photo. I've taken all three major calculus courses for physics, linear algebra, ODE, PDE, Complex Analysis, etc. However, I do still struggle with rules for...

I am reading Electrodynamics by Griffiths, and in section 2.5, he mentions that one of the properties of a conductor is that the electric field just outside the conductor is perpendicular to the surface of the conductor, and gives the following image: However, I don't understand why the...

Is it really possible to explain the concepts of vectors and pseudovectors (differencies) only using the simple mathematical structure used by authors like Griffiths (Introduction to electrodynamics), as the claim to do, without using more deep mathematics like group theory, etc? Reading the...

I'm looking to brush up on my knowledge of electrodynamics and am trying to decide between Jackson and Griffiths. I have a fairly advanced math background and am comfortable with differential geometry, special and general relativity. I'm leaning toward Jackson but wanted to get input from...

I don't understand anything about how 1.18 came to be (Red Rectangle), any help would be greatly appreciated!

Robert Griffiths version of consistent histories can be presented as a quantum logic, which is "intentionally" incomplete as an interpretation of QM. The advantage is that one can just require the exact decoherence condition ##D(\alpha,\beta)=0## for all ##\alpha\neq \beta## (with the...

Hi. I believe I have what may be both a silly and or a weird query. In many Griffiths Problems based on Electric Field I have seen that a coordinate system other than Cartesian is being used; then using Cartesian the symmetry of the problem is worked out to deduce that the field is in (say) z...

I'm currently studying Griffiths electrodynamics on my own and I want to be done with it once and for all. I however don't know if all the chapters are important for the rest of physics and which ones can be skipped without loss of continuity. Can someone give me some insight?

Hi. I have solved the problem below as shown in the attached image. However I'm at a loss to figure out where I am making a mistake, and I know it is indeed a big goof up. Requesting guidance over identification and rectification of this big goof up. (Edit- I can solve this problem in the...

I apologise if this has been answered before. I am about half way through the mechanics chapters in the classic University Physics I am wondering when I get to the chapters on electromagnetism is it worth reading them if I’m going to be reading Griffiths anyway? Would it be best just to get...

Griffiths "introduction to elementary particles" serves a great introduction as a first course on particle physics for undergraduate students. But what are the possible alternatives of this textbook? Like being more beneficial in the long run, more time-consuming, for aspired students. But it...

I am a undergraduate student and have done some studying from Resnik book (principles of physics). I have also got Feynman lectures vol1 which I am planning to study with Resnik. I think it will give me a solid grasp on theory. I am getting bored now after doing some chapters from...

While I was doing a problems of chapter 9 of DJ griffith electrodynamics I came across this problem 4 Problem statement Obtain eq 20(show in the below picture) Directly from the waves equation by separation of variable Could I have a straight solution in your word Thank you

Summary:: The problem solutions contain a lot of unjustified steps, making them pointless. I am trying to use Griffiths Introduction to Quantum Mechanics. He states that the wave function ##\psi## approaches 0 as x approaches infinity to make normalization work. I can accept that. But then I...

intermolecular distance means distance between particles. So, I imagine a sphere. $$\frac{4}{3} \pi d^3 = \frac{V}{N}$$ However, Griffitfhs pictures a box instead, where $$d^3 = \frac{V}{N}$$ And the difference between both models is a factor of ##(4\pi/3)^{2/5} \approx 1.8##, which is...

Hi! Does anybody know if, and if so where, to find solutions for the textbook on elementary particle physics by David Griffith? I would like to compare my results to check if I am doing it alright. Thanks gluon

Griffith's says this, and I'm not exactly sure why... If you had a solid, spherical, and externally induced conductor... Does this mean that IMMEDIATELY outside, when you're infinitesimally close to the surface, E looks like this? If you surround the entire conductor with a Gaussian surface...

In the 3rd edition of the Introduction to Quantum Mechanics textbook by Griffiths, he normally does the notation of the expectation value as <x> for example. But, in Chapter 3 when he derives the uncertainity principle, he keeps the operator notation in the expectation value. See the pasted...

In Griffiths Quantum Mechanics 2nd edition, in Chapter 8 he calculates the following integral on page 323 and he gets I disagree with this result, I think the integral should be since Maybe somebody can explain why I am wrong? Also, from equation 8.24 to 8.25, he makes the assumption that...

Hello! I was wondering if there'd be any problems using another QM book (like Shankar, Ballentine etc) in a course where the standard literature is Griffiths Introduction to Quantum Mechanics? By that I mean is there ever any disadvantages to going to a more advanced textbook (assuming you...

Summary:: Griffiths problem 8.5 Problem 8.5 of Griffiths (in attachment) I already solved part (a), and found the momentum in the fields to be $$\textbf{p}=Ad\mu_0 \sigma^2 v \hat{\textbf{y}}$$ In part (b), I am asked to find the total impulse imparted on the plates if the top plate starts...

Firstly, apologies for the latex as the preview option is not working for me. I will fix mistakes after posting. So for ##<x>## = (##\sqrt{\frac{\hbar}{2m\omega}}##) ##(< \alpha | a_{+} + a_{-}| \alpha >)## = (##\sqrt{\frac{\hbar}{2m\omega}}##) ##< a_{-} \alpha | \alpha> + <\alpha | a_{-}...

In "Introduction to Quantum Mechanics", Griffiths derives the following formulae for counting the number of configurations for N particles. Distinguishable particles... $$ N!\prod_{n=1}^\infty \frac {d^{N_n}_n} {N_n !} $$ Fermions... $$ \prod_{n=1}^\infty \frac {d_n!} {N_n!(d_n-N_n)!}$$...

Hi folks, I'm currently working through Griffith's E&M text for school. It is my favorite subject and I am hoping to find another textbook or problem book on electrodynamics or electromagnetics. I was hoping for something at the level of Griffiths or slightly above, something that'll prepare me...

Although Stokes Theorem says that the line integral of a closed surface equals to zero why do we get a non-zero value out of this question 1.11 (and figure 1.33) in the Griffits Introduction to Eletrodynamics Book?

I worked out the expectation values of the components of a 1/2 spin particle. However, I'm confused about Griffiths notation for the x and y components. For the x component I got, ## \left< S_x \right> = \frac \hbar 2 (b^*a+a^*b)## which is correct, but Griffiths equates this to ##...

I have a copy of Griffiths Introduction to Elementary Particles (1st Edition) and was thinking of beginning to work through it. I was curious if anyone knows if this text is sufficiently up to date or if there have been any major developments in particle physics that would make it worth getting...

Attempt:

Hello, In Griffiths Intro To Quantum (second edition) example 4.3 page 180 ... Calculating the expectation of <Sx>, equation 4.164. I'm sure I am wrong, but it seems like after using Euler's for the e^i terms there should be 2cos(yB0t)'s terms. I agree the sin's cancel (After using Euler)...

Hello, again. My current interest is quantum computation. I've finished Griffiths' QM for the first time. Because it only takes me a month studying the book, I may have study it superficial, so I plan to study it again and complete all the problems after each chapter. Then is this book...

Hello, In Griffiths (2nd edition) pgs 110-111 - deriving the uncertainty principle I have 2 questions 1) I am stuck on a point ... (h = ^ hat ) <f | g > = < ( Ah - <A>) ψ | ( Bh - <B>) ψ > = <Ψ | ( Ah - <A>) ( Bh - <B>) Ψ> FOIL = <ψ | AhBh ψ> - <B><ψ | Ah ψ> - <A>< ψ | Bh ψ> +...

Hello,I have been going through Griffiths’ Intro To Quantum Mechanics in an attempt to self-teach myself some quantum mechanics. I am currently in section 3.4 (Generalized Statistical Interpretation) I am seeing a “step” occur more than once. When I first came across it, while I didn’t...

Why from Φ eq in page 136, he did not derive the solution in this form $Ae^{imφ}+Be^{-imφ}$https://drive.google.com/open?id=1thokDDIVDytck1-2HI3qyiG07mAMO1nc

Hello! I am reading about image charges for an infinite plane and a charge above the plane. In the book I am reading (Griffiths) the author says (and uses this results several times) that the field below the plane is 0. How do we know this? The method of the mirror charges gives the V above the...

Homework Statement Hello, This is not a homework help problem but I believe this question belongs here more so than in the other forums. I would like to (for personal benefit) duplicate / generate the plots in Figure 2.6 of Griffiths Quantum Mechanics book - page 55, 2nd edition. Homework...

Hello, I will be starting my junior year this August, I shall be having the dreaded advanced electromagnetism course that follows Jackson's book the coming semester. Unfortunately, I didn't work very hard during my freshman year e/m course (which uses Griffiths' book) and have a few gaps in my...

Homework Statement Hi, I was reading Griffiths and stumble upon some questions. This is from 5.1.2 Exchange Forces. The section is trying to work out the square of the separation distance between two particles, $$\langle (x_1 - x_2)^2 \rangle = \langle x_1^2 \rangle + \langle x_2^2 \rangle -...

Homework Statement Homework Equations This is solution of Griffith problem 11.16 The Attempt at a Solution This is procedure to get a 1-D integral form of Schrodinger equation. I don't understand why that contour integral include only one pole for each contour?

In Griffiths fourth edition, page 413, section 9.4.1. Electromagnetic Waves in Conductors, the complex wave number is given according to equation (9.124). Calculating the real and imaginary parts of the complex wave number as in equation (9.125) lead to equations (9.126). I have done the...

I have a few issues with understanding a section of Griffiths QM regarding Hermitian Operators and would greatly appreciate some help. It was first stated that, ##\langle Q \rangle = \int \Psi ^* \hat{Q} \Psi dx = \langle \Psi | \hat{Q} \Psi \rangle## and because expectation values are real...

Homework Statement [/B] 1) I don't quite understand what 2.94 means on its own. It was derived from 2.93, yet it doesn't show a superposition of any sort. The author then takes 2.94, and attempts to normalise it by stating ##\int \Psi_k^* \Psi_k dx = \mid A^2 \mid\int dx = \infty ## What...

I try to learn electrodynamics as theoretical physicist, Now I study from Griffiths, I find it very good book and do the job! but the problem I need to learn electrodynamic to do future topics like Quantum Electrodynamics, and Pollack I find it good and modern, so my question is what is the best...

Hi, I recently ordered the fourth edition of "Introduction to Electrodynamics" by Griffiths. However, I received the international version of the textbook. In my upcoming course, our homework will be made up of problems coming directly from the original version. So, are the problems in the...

Homework Statement A few questions: Q1) How does 1.29 flow to 1.30 and 1.31? How was the integral-by-parts done? Q2) The author states that <v> = d<x>/dt represents the expectation value of velocity. What does this actually mean? I tried to rationalise that d<x>/dt represented the velocity...

Homework Statement construct ψ(x,t)^(2) where ψ(x,t) = 1/5(3ψ_0(x)e^(-iE_0t/ħ)+4ψ_1(x)e^(-iE_1t/ħ). I know we square it but we have to find E_0 and E_1 and put it in. Homework Equations E_n = (ħ^(2)k_n^(2))/2m = (n^(2)π^(2)ħ^(2))/2ma^(2) The Attempt at a Solution E_0 = 0 and E_(1) =...

Hi. I'm going over the discontinuity aspects of the electric field as we cross the surface charge. A pillbox Gaussian surface was drawn and the electric field for "below" is throwing me off. Can someone explain why the electric field is pointing in the same direction from both sides of the...

1. Amazon link: https://www.amazon.com/dp/0131118927/?tag=pfamazon01-20 ISBN: 978-0131118928 This is the book that my class syllabus suggests based off ISBN number, however it is $119.00 to buy off Amazon. 2. Amazon Link: https://www.amazon.com/dp/1107179866/?tag=pfamazon01-20 ISBN...

Hi, I've 2 em texts: Purcell, ( Electricity&magnetism ) and the Griffiths (intro to electrod.) On which of the two, is best to study ?

Hello all! You'll see, I am self studying physics, and have already finished with Kleppner - Kolenkow mechanics (complemented with Morin) and Griffiths electrodynamics. Now I think I am prepared for QM, but I do not know which textbook is better for me. I have reduced my options to Griffiths...

Homework Statement Starting from the Lorentz force law, in the form of Fmag = ∫ I (d× B), show that the torque on any steady current distribution (not just a square loop) in a uniform field B is m × B. Homework Equations I looked at the solution I found in this thread here, but I don't...