Term Definition and 742 Threads

In the context of cosmic rays?

Hello guys, Suppose a process 1+2--->3+4 proceeds thru 3 different intermediate particles and has 3 Feynman diagrams. When we compute the probability then what does the cross terms( interference ) mean? and do we have to always compute the cross terms? What I mean is that when you have 3...

well ... we are studying bethe and weiszacker semi empiric formula , and i am confused . specifically about the third term the asymmetry term and how it lowers the binding energy . so just so i know that i am getting this straight , originally the binding energy no matter the nucleus is...

Hi all, A question about the vacuum energy density and spectrum. The only spectrum that is frame invariant involves the cube of the frequency. Is it also possible to have a constant offset term (which would also be frame invariant), to 'adjust' the energy density so it doesn't turn out to be...

Hi, I am struggling to find the solution to the following equation. I can't account for the exponential term, so clearly something is going wrong... 1. Homework Statement Find the general solution to ##x' = tx + 6te^{-t^2}## where ##x(t)##. Homework EquationsThe Attempt at a Solution [/B]...

I'm an applying high school student. I know something about the field so don't worrying talking about the subject itself just assume I know how research works. I want to know how does it feel like to be a student in UCSB physics department if you want to have high-energy particle physics as...

First - I'm not medically trained - this question comes about because of a relative being prescribed these. As I understand it ant-acid drugs neutralize the natural acids in the stomach the body makes naturally in order to digest food. Given my limited knowledge of basic chemistry I can see...

Hello Guys, This is my first time posting here - just wondering if anyone has some insight on a project that I am working on. I want to be able to temperature control an insulated shoe box sized volume at ~5 degrees Celsius for about 20 minutes. The main constraints are that I would need the...

Is E=mc2 the potential energy of a mass m? Is it the maximum energy such a mass can have? What is the correct term used to denote E in this context? For example, if an object is traveling at 10% of the speed of light, could one say it has a kinetic energy of 0.5 x m x 0.1² = 1/200th of its...

In reading mathematical texts (especially on functions), I come across the term "pointwise". There seems to be a paucity of information explaining it on the internet, so I turn to the forum for an intuitive explanation. The context is when the term is used as in "pointwise addition" or...

Homework Statement [/B] If particles at B and C of equal mass m are connected by strings to each and to points A and D as shown, all points remaining in the same horizontal plane. If points A and D move with the same acceleration a along parallel paths, solve for the tensile force in each of...

When deriving the conserved currents from continuous symmetries, my book states that we can also add a 4-divergence to the lagrangian density which does not change the action under variation. The four divergence can be transformed into a boundary integral by stokes theorem. However, my book...

I always see the contribution of semiclassical scattering to the Bloch equations for a two-level system justified heuristically, using Fermi's Golden Rule to calculate the scattering rates. The resulting time evolution of the density matrix is clearly in the Lindblad form, but is it possible to...

@cabraham I recently posted a short derivation of Poynting's theorem in https://www.physicsforums.com/threads/work-done-by-magnetic-field.825806/ It reminded me of our conversations about Poynting's theorem in a motor. As we discussed earlier, the work term ##E \cdot J## includes all the...

How to explain the term quantum mechanics to a class in 10 minutes? I may need to do this in an oral exam where the professors are from English department. Whiteboard can be used. My presentation should include one or more of the following:· Examples (practical and/or personal)·...

$$5^{2}S_{\frac{1}{2}}$$ My guess is five-two-S-one-over-two. Any suggestion is appreciated. Thanks.

Is ther a term for the space that the expanding universe has not reached yet. Is it called a void or is it some other term. Also if you could link some articles about this space the universe hasnt reached yet I would love to read about it. Thank you all.

Homework Statement { 7/6 , 45/54 , 275/648, 1625/9720 ... } Problem from a practice exam. My instructions are to find an explicit formula for the above sequence.. The Attempt at a Solution Let An =7/6 , 45/54 , 275/648, 1625/9720 ... Allow An = Bn / Cn Bn = 7, 45, 275, 1625... (2n+5)...

I want to know the sign of the cosmological term. It seems that in the left hand side of the Einsetein equation the cosmological term is -\Lambda g_{ik} for (+---) convetion or +\Lambda g_{ik} for (-+++) convetion. Right? Best

What does the following statement below mean? "The excluded volume is not just equal to the volume occupied by the solid, finite-sized particles, but actually four times that volume. To see this, we must realize that a particle is surrounded by a sphere of radius 2r (two times the original...

In order to transfer on time from community college and prepare for the MCAT I have to really scrunch my classes. I was planning on taking Calc 3, Liner Algebra, O Chem 1, and Physics 1 (mechanics) at a whopping total of 19 units in 16 weeks. Is this doable? I would not be working and all of my...

Hi, I'm new to the forum, and I am very sorry if this has been asked before. I am Japanese and therefore my English might be a little bit awkward. I want to ask about term symbols and if they can be used to derive electron configuration in lanthanides. First of all, I do not major in Physics...

Homework Statement [/B] Here is an nth term test for determining divergence, I think I have it, but wanted another opinion -- 1/34 + 1/35 + 1/36+ … + 1/1,000,034 -- IHomework Equations ∑(upper limit ∞)(lower limit n=0) 1/(n+34) The Attempt at a Solution 1/34 + 1/35 + 1/36+ … + 1/1,000,034...

I go to a university that operates on a three quarter per year system, with 10 weeks per quarter. This quarter started out fine, but my dad's condition suddenly deteriorated and he passed away (I was led to believe he had at least 2 years left from doctor expectations about the development of...

We have the formula for the mass of an atom: From our class notes I have: Please could someone explain how he manages to get a single parabola from the pairing term? All I understand about the pairing term is that ap<0 for Z,N even, even. ap=0 for A odd and ap>0 for Z,N odd, odd. At a loss...

Why cosmological constant term ##\Lambda g_{uv}## in Einstein equation is proportional to ##g_{uv}##. Why it is even proportional to ##g_{uv}## in spacetime of MInkowski?

Homework Statement I'm looking at solving a simple theory of massive gravity for Scwarzchild type solutions. I've attatched the paper that I'm working with. I've tried to add the 3 possible cubic terms to L_mass parametrized by constants. It doesn't seem possible to solve for B as a function of...

consider a 1-D problem where a charged particle travels along +x with a bound state energy. the vertical potential energy axis is displaying information about the force that is parallel to the particle's axis of motion. is this correct? so then this would be an accurate representation? where...

Homework Statement for example: ##\frac{\partial(F^{ab}F_{ab})}{ \partial g^{ab}} ## where F_{ab} is electromagnetic tensor. or ##\frac{\partial N_{a}}{\partial g^{ab}}## where ##N_{a}(x^{b}) ## is a vector field. Homework EquationsThe Attempt at a Solution i saw people write ##F^{ab}F_{ab}##...

We know that Fourier Transform F(W) of function f(t) is summation from -infinity to +infinity product of f(t) and exp^{-j w t}Here, what does the exponential term mean?

Hi. First off, sorry if this is the wrong forum; this seems to be the most valid one, but if that's not the case please let me know. Anyway, I am writing a thesis, and in it I mention the Michel electron (electron created from muon decay) and note that it gets its name from Louis Michel. I was...

Homework Statement Derive the momentum for a charged particle going through matter. Homework Equations None. The Attempt at a Solution I understand the derivation but there's one step I am not clear about, and I'm probably being really stupid but this: if the -infinity term is squared then...

The sum of the first 100 terms of an arithmetic progression is 15050; the first, third and eleventh terms of this progression are three consecutive terms of a geometric progression. Find the first term, a and the non-zero common difference, d, of the arithmetic progression.

Terrm symbols are really letting me confused. A spectroscopic term or term symbol is used to identify different arrangments of a given electronic configuration. For example, to carbon in ground state (1s² 2s² 2p²) there are a lot of different possible values for ml and ms, and term symbols can...

Hey guys, So I'm reading a textbook which has the following equation: \dot{X}^{-}\pm X^{-\prime}=\dfrac{1}{4\alpha' p^{+}}\left( \dot{X}^{I}\pm X^{I\prime} \right)^{2}. Please note that the +,-,I are indices. Then the author says: \dot{X}^{-}= \dfrac{1}{4\alpha' p^{+}}\left(...

How do i go about deriving a general eqn for the nth term of a sequence provided an eqn of the sum to the nth term is given in terms of n?

Hi, I've been thinking about the Navier-Stokes equations and trying to build skill in implementing it in various situations. In a particular situation, if I have a fluid flowing down an inclined surface such that it forms a film of finite height which is smaller than the length of flow, there...

Where does the Stern Gerlach term in the Pauli equation come from? Taken from http://en.wikipedia.org/wiki/Pauli_equation. Following wikipedia's steps the Stern Gerlach term pops out when you apply the Pauli vector identity. I don't understand this step. It seems as if there should be no Stern...

Homework Statement Consider a uniform rod of mass 12 kg and length 1.0 m. At its end the rod is attached to a fixed, friction-free pivot. Initially the rod is balanced vertically above the pivot and begins to fall from rest. Determine a) the angular acceleration of the rod as it passes...

Please note that I'm asking about interlocking OF crystals not "interlocking crystals "

What do you mean by the term "energy density of radiation " between the frequency range f and f +df ?

Why 2-Bromopropane is called isopropyl bromide?I am concern about term iso.I have been told if there is one CH3 group as a substituent on the c atom next to end c atom then we use term iso but here in 2-Bromopropane there is no ch3 group on the c atom next to end c atom one ch3 group does...

I'm having trouble simplyfying this, I guess there's a trick but for the life of me can't remember what it is. Here is what I have so far: ##\omega ^{2} = f\left ( \frac{1}{m}+\frac{1}{M} \right )-f(( \frac{1}{m}+\frac{1}{M} \right ))^{2} - \frac{4q^{2} a^{2}}{mM})^{\frac{1}{2}}## so I divide...

I am trying to make a term for a function equipped on an image sensor. The term is to express "the upper limit of fluctuation allowance in image size which is specified in %" The value of percentage does not express the ratio of the enlarged image size compared to the original image size, so...

Homework Statement The ratio of sums of 2 AP for n terms each is ## \frac{3n + 8}{7n + 15}## that is $$ {\frac{s_a}{s_b}} = \frac{3n + 8}{7n + 15} $$ find the ratio of their 12th terms. $$ Required= \frac{a₁_a+(n-1)d_a}{a_b + (n-1)d_b}$$Homework Equations Tn = a + (n-1)dThe Attempt at a...

Hi, I am doing an introductory course on fluid mechanics, and I'd like some intuition (that's why I'm posting on the engineering forums and not on the math forums, even if I'm studying for a degree in math) about the concept of the total derivative and, particularly, its convective component...

I had a small question, which one contributes more to evolution: 1)short term adaptation and heritable 2)long term adaptation and heritable ?

How do you call of the digital image processing that simplifies an image by reducing the amount of pixels? I thought of the word “thinning”. But according to ”Fundamentals of Digital Image Processing” by Anil K. Jain, “Thinning algorithm transforms an object to a set of simple digital arcs...

Hi all, given the sum of a series and a single term how would one find the nth term? Any help appreciated.

I'm having trouble figuring out how the term below boxed in red was eliminated on the left side of the equation as shown below. I reviewed properties of exponential functions, and still can't understand how this term was cancelled. 1. Homework Statement Homework Equations Exponential laws...