Physical Definition and 1000 Threads

Hello, Just wondered what the correct way is to display physical units on chart axes. Let's say for example thermal resistance of a heatsink extrusion is plotted as a function of length, and so the units for the y-axis are K.W-1 My 'A' Level physics teacher always insisted on (in order...

Hi. So if you have \frac{d p_{\alpha}}{ds} = \frac{q}{c} F^{\alpha \beta} u_{\beta} how could you possibly go on proving this its form is invariant under all coordinate transformations? Or any physical law of any form, really? I guess my point is how do you represent "all possible...

Need a physical picture! The electric potential of some charge configuration is given by V(r) = A*e^(-λr) / r Its Electric field is E = A*[(λr+1)/(r^2)]*e^(-λr) \hat{r} And its charge density is ρ = 4*pi*A*ε0*δ(r) - [(ε0*(λ^2)*A*e^-λr) / r] , where δ(r) is delta function. The thing that...

I'm trying to understand the Heisenberg Uncertainty Principle, as it relates to experimental measurements, because it's kind of confusing me. We just learned the derivations for it in my QM class -- basically it's two standard deviations multiplied together (corresponding to measurements of...

Does anyone have a solutions manual for the biophysics textbook, Physical Biology of the Cell. Or a link/login info for an online copy?

What is the physical (i.e. molecular/chemical) difference between a normal star and a Cepheid Variable? Do we know and if so can we explain what gives rise to the specific period-luminosity tie? Thank you.

I've been searching for a good book on Calculus that is great for self-study, and at the same time, walks the reader through the WHY behind the math. I am farely upset at how today's educational institutions teach math as plug-n-chug subject without walking the students through the underlying...

Can someone give a physical meaning for imaginary numbers? The imaginary numbers, in my opinion, are truly imaginary. What do they even represent? Irrational numbers are, well, preposterous but I can accept them. √2, π and φ have some tangible meaning, but √(-1)? What does it mean? A solution...

Can all formulas be thought of intuitively/physically? For example, average speed is change in distance over change in time, that is intuitive and can easily be derived But when you have something like v^2 = u^2 + 2ax, or e=mc^2, how do you think of it intuitively? Specifically the squared...

It is an old idea that, at least in principle, hidden variables could be local if they are superdeterministic. However, so far this idea seemed too speculative for highly respectable journals such as Physical Review Letters to publish research on it. But now it seems that it has changed. The...

Homework Statement The distance between crystal planes in a KCl crystal is about 3.14 \times 10 ^{-10}m. Calculate the Bragg's reflexion angle of first order for electrons with kinetic energy of 4keV. Compare it with photons that have the same energy.Homework Equations \lambda n =2d \sin...

Mathematical Methods in the Physical Sciences (3rd edition) by Mary .L. Boas, Does this book has separate solution manual?

Dear all, is the relation between chemical composition of a material and its physical properties a peering relation or a relation of subordination？

So "A shell of uniform charge attracts or repels a charged particle that is outside the shell as if all the shell’s charge were concentrated at the center of the shell" and also, "If a charged particle is located inside a shell of uniform charge, there is no electrostatic force on the particle...

Homework Statement 1. Ideally, the handle of a frying pan should not get hot while you are cooking with it. Based on the information listed in Table 2.8 of your textbook (or 2.7 in 8th, 2.6 in 7th ed.) choose the substance below that would be the best frying pan handle material. Assume that...

Hi:) A question that I don't understand, and my feeble attempt to answer it. Can anybody give any heads up on this one? If a physical quantity is dimensionless, it has no units attatched to it. Determine if the following constant is dimensionless and show your reasoning" \alpha=...

I'm looking for what might be best for simulating various physical phenomena - some examples off the top of my head might be how to create an animation of a double-pendulum, or a system of 250 particles that are mutually interacting, confined within some box, in an arbitrary external field (like...

Strength, endurance, speed, control, etc. -- what measure of sport have you most excelled in?

Firstly hello, this is the first time I have posted here (although I have used the site to find info in the past). My query is best illustrated, I think, with an example. Suppose we have some physical system with corresponding state vector \left| \psi \right> = a \left| 0 \right> + b \left|...

How are the various physical laws enforced in the universe? Even if there was only physical law out of which other laws manifest, how is that one physical law enforced?

I've seen that in English you refer to the measurable physical properties as http://en.wikipedia.org/wiki/Physical_quantity" , but some sites call them "physical magnitudes". Are both of them correct?. Do you consider them as synonyms? In Spanish we say "magnitudes físicas", and I wonder if...

Hello! I have just rediscovered this place since a few years back when I first signed up. This will be my first post, so forgive me if it is a bit long. I have been thinking about this for a while. So I have been thinking about buoyancy. I have learned that the buoyancy force is caused by...

I have been self studying this book by Mary L.Boas for a while which is a treat to study for its great depth. However, the problem of mine is though I have been able to solve most of the problems of this book, there are some really tough Questions in this book which are very hard to solve. So...

i know that del.v=divergence of vector v and del x v=curl of vector v can anyone justify for the same? how dot product is physically connected to divergence property?

I know that the physical meaning of SU3 and SU2 - you can change the places of the quarks or/and leptons and you will get the same results. What is the physical meaning of U1, and O3,1 (Lorentz group if I am not wrong)? I know U1 is connect with the Polarization of the light. Thanks...

Homework Statement The problem is from Mathematical Methods in the Physical Sciences, 3rd Ed. Ch10, Sec. 10, Q4. My question is a bit subtle as I have actually figured out the problem, just that I don't understand my solution. The problem reads: 4) What are the physical components...

Hello friends, I am finding it a bit difficult to comprehend what the author of a famous textbook has written about TV signal band width. Here is the excerpt from his book. Could any of you please explain what exactly he means? I don’t get why the required bandwidth is around 5.5 MHz...

Hi, Could someone tell me, or refer me to a reference, about what the physical separable hilbert spaces are for the electroweak and strong forces. I'm looking for a defined inner product for the theories and a rigorous account of their hilbert spaces. Thanks a lot,

Hello, I was wondering what the true difference between Physical Chem and Chemical Physics was. And also, I would like to know if anyone knows a good undergrad school for either one? Thanks!

I understand how to calculate all three of these, but what is their physical function. How do they physically manipulate the environment we are trying to describe through mathematics? Please don't use any formulas to explain this. The formulas are easy, the physical meaning is what I'm...

"physical" interpretation of the Laplace operator Is there a "physical" interpretation of the Laplace operator, much like there exists a physical interpretation of the divergence and curl?

Does anyone have the Latex Model for Physical Riview Letters or Physical Riview B? If anyone have, can you send me the model to me? I really need it. Thank you very much!

physical interpretation of the "rotation" of a ket Homework Statement No problem statement. I'm just having trouble imagining what it means to "rotate" a quantum -ket, especially since not all -kets are eigenstates of position. I know what the rotation operator is. I also can picture...

I'm curious if anyone has and physical intuition that would lead to non commutative geometry? I mean on one hand we have NCG as a branch of math, which explores what mathematics you get if you try to replace som commutativity requirements in normal geometry etc. This may or many not interest...

Simple thought experiment I read and would like to hear what others think will the result will be: Let two spaceships A and B accelerate along a straight line. Observer C does not accelerate. The accelerations, as judged by C, are constant for both ships. Each ship is equipped with a...

Is there any physical significance of the matrix terms such as cofactors and minors? I state that this is used for finding the inverse but that is rather an abstract concept and does not motivate the student . Is there any real life applications of these terms.

A former sea captain recounts a stormy night in Atlantic when he observed waves with wavelengths of a few metres passing his 51m long ship in less than 3s. Should you believe him? How do we go about answering this question? I have no idea where to start from, well, we learned about group...

I am looking for copies of Physical Science: An Introductory Study by William A. Andrews (ISBN: 0136714463) to use as a lab manual. (Please see attachment for photo of book cover.) I tried to order 30 copies from BiggerBooks.com, but they were unable deliver on the contract. I have purchased...

These can be classical or quantum. There is no correct "answer" and everything is based on your preference. But in general let us stick to "elegant" processes which arise as "surprising" or "very easy to understand" solutions regardless of how complex the underlying equations and formulations...

I was reading the text of electricity and magnetism by griffiths. Here I read a term called magnetic potential but I did not completely understood the physical essence of the term, neither it is explained in the book. It should have some physical interpretation as it is named a potential. In...

I am majoring in physics with a minor in chemistry and I am wondering if taking two semesters of physical chemistry as an option for the minor would be redundant. From looking around I have seen that the first semester is watered down thermodynamics and the second semester is about quantum...

Hi my friends I'm Abdulrhman from KSA I just finished my BC degree at physics before 1 year Now I'm planing to continue my study (Ms &PHD) degree I've select Quantum Optics at TAMU (Texas A&M University) at USA to do my grad study But I'm worry because I fill my background is not good...

In special relativity physicists talk about time dilation, saying that as an object moves faster relative to another that its "clock" moves slower and therefore time slows down. Could it be fair to say that time doesn't actually slow down, but all matter and energy reactions slow down and...

Dear all, I'm trying to understand better why gravity makes impossible to physically define an inertial reference frame. Firstly, we must have an operational procedure that allows us to physically define an inertial reference frame. Secondly, we must show that gravity makes this procedure fail...

I recently learned that Kramers-Kronig relations can be applied to physical response functions, but I find it strange that for eg. the refractive index and absorption of a material cannot be independently defined, what is the explanation behind this from the point of view of the physics...

Hi, I am reading up on special relativity and I'm having some trouble understanding how tensors fit into the picture. Its my first contact with these concepts so please forgive me for being very muddled. My main problem is understanding how to see whether a physical law is compatible with...

Homework Statement A very light rigid rod with a length of 0.516 m extends straight out from one end of a meter stick. The combination is suspended from a pivot at the upper end of the rod as shown in the following figure. The combination is then pulled out by a small angle and released. a)...

I know that it corresponds to the 1/r^3 term in the Taylor series expansion of the gravitational force. But Taylor series expansions can't give me any physical intuition. By physical intuition, I mean that I want to know why the coefficients for the 1/r^3 term are the way they are.

Can someone give me examples of mathematical solution to the Maxwell’s equations that have no physical meaning?

When dealing with the Euler-Lagrange equation in a physical setting, one usually uses the Hamiltonian L=T-V as the value to be extremized. What is the physical interpretation of the extremizing of this value?