Explain Definition and 1000 Threads

http://www.youtube.com/watch?feature=player_embedded&v=3W-FSqRATgw"

This is what I want to say: The squeeze theorem may be used when direct substitution and factoring (or simplification of any sort) doesn't help in finding a limit. An example would be lim x->0 of x2sin(pi/x). Limit laws wouldn't work and we can't simplify the expression. What we can do is...

For retarded scalar potential of arbigtrary source around origin: V(\vec r, t) = \frac 1 {4\pi\epsilon_0}\int \frac { \rho(\vec r\;',t-\frac {\eta}{c}) }{\eta} d\;\tau' \;\hbox { where }\;\eta =\sqrt{r^2 + r'^2 - 2 \vec r \cdot \vec r\;' } Where \;\vec r \; point to the field point where V...

Can/do relativistic effects explain select quantum "phenomena" Can/do relativistic effects explain select quantum "phenomena"? A photon (a mass less "particle" that travels at the speed of light) experiences space-time in a different manner. A photon does not experience time. Would the sun...

I am recently reading the articles "Search for squarks and gluinos using final states with jets and missing transverse momentum with the ATLAS detector in sqrt s=7 TeV proton-proton collisions". However, as my limited knowledge, many technical terms that I am understanding as a result I am now...

Im having a little bit of trouble with SuperSymmerty. I understand all the basics with the sparticles and gauginos being -1/2 less and how their properties change to boson-like and fermion-like respectively. What i don't understand is how do the interact exactly. i know none have been found in...

this problem was discussed by our professor . but I am a lil bit confused on it ! thanks ! help ! FIVE COPLANAR FORCES ACT ON AN OBJECT AND THEIR RESULTANT ! our prof use this formula ! Bx=Bsin(degree) By=Bcos(degree) ANSER: VECTORS X-COMPONENTS...

I've gotten quite used to that light is both a wave and particle but how does it interact with objects?

I fail to understand a step made in this proof: http://en.wikipedia.org/wiki/Convolution_theorem" more specifically the last step where the integral is written as a product of 2 separate integrals (each equal to a Fourier transform): from: to: I'm quite rusty on my integration, but as far I...

Homework Statement n2<=2n n is a natural number For what values of n is the statement true and prove by induction. Homework Equations The Attempt at a Solution I tried 1 and it worked, I tried 2 and it worked, just for fun I tried 3 and it didn't work, so I assumed the...

Please teach me this: How to understand the smallness of mass while the mass parameter diverge rapidly in renormalization group flow because the mass term in Lagrangian is the relevant operator.By the way,are there always exist the fix point of renormalization group flow in any QTF Theory,or in...

How would you in few words explain 'force'? Could you say: A force is the acceleration of mass.

Like has anyone ever said a reason to how matter and energy came into existence?

Homework Statement A truck start from a place with an acceleration of 2m/second square.A car passes the same place after 5s with uniform speed of 20m/s. Find the time taken in which car overtakes truck? Homework Equations The Attempt at a Solution Answer given is 10 seconds...

I am studying the multi variable Inverse Function Theorem and the Implicit Function Theorem. I think my brain is rebelling against understanding them and I would appreciate if someone here could explain the two theorems semi rigorously as well as explain when they are used, and why they are...

What is a non-inertial reference frame? how is it defined?

OK, so recently I have learned that in the early 20th century, while Max Planck was attempting to explain the quantum nature of light, two men named Philip Lenard and Heinrich Hertz discovered the photoelectric effect. They found that an electron must absorb a specific amount of energy...

[PLAIN]http://blog.bfg9000.co.uk/wp-content/uploads/2010/11/pi_equals_4.png Could someone explain the error here?

While reading about Minkowski's description of the fourth dimension time axis, I saw that by taking the product of the speed of light and time, he was able to give it a "spatial" geometric character of distance (i.e. light-years, light-seconds, or whatever). I then saw that he set c (the speed...

This might be a bit of a naive question but I am only just starting to learn the very basics of this stuff. I'm hearing about being able to account for the mass of, well, massive particles, by saying that in our cool universe, there is this field pervading all of space that certain...

I am trying to figure how the pins of 8086 are connected to different elements in the circuit? I don't understand how at this level the pins can be connected. can you explain? Is the second diagram suppose to be the internal view of the first diagram? The figure shows that there are 40 pin on...

"The meter is the length of the path traveled by light in vacuum during a time interval of 1/299,792,458 of a second.Note that the effect of this definition is to fix the speed of light in vacuum at exactly 299,792,458 m/s." I don't understand this because how can you use a number based on...

So to determine the position of an object you can scatter light off of it. Fine. But then my textbook says you can't know the exact position of the object because of diffraction effects. We've covered the diffraction of light through narrow slits but I don't know why if you were scattering light...

Hello everyone. I'm not a physicist however have been doing some research on the concepts behind dark energy and string theory and it has presented me with a question: Is it possible that dark matter could be the components of quarks that haven't pulled together to form the quarks. We can't...

Can someone please explain this concept for me? As I understand it, you have a, let's say, a three-level atom with two hyperfine states and an excited state. Then you apply a pump source (perhaps a laser) to transfer the atom from one of the hyperfine states (say |g1>) to the excited state...

could anyone explain to me that why: let u=E[X]. then E[u]=E[X]? I am a bit confused. Thanks.

Can someone explain to me "Locality" in field theory? I know that two fields have to commute at space-like separations so that observations don't affect each other at these separation. what about the thing where the Lagrangian can't couple fields at different locations and time, is it so...

I was watching one of Susskind's videos and I had some questions: Briefly summarizing from the video: E = hf (Planck's constant times frequency) E = cp (speed of light times momentum) or p = E/c = hf/c And we know that if we have wavelength lambda, then if t = 1/f and vel = dist/time...

Anybody here who could explain to me in the simplest terms what is so special about the Lie group SO(8) and what is meant by triality? I know some Lie and representation theory, mostly from physics books. As I understand there are vector and spinor representations for so(n). If n is even...

so just about finishing a report on x ray abosprtion on different materials, generally the linear attneuation coefficent increases with atominc number Z. However silver(47) had a lower attenuation coefficent then zirconium(40) despite having the significantly higher value of Z. With some...

A local velocity-dependence of local curvature of space would violate the notion that space is given a curvature only by surrounding matter. Any arbitrary test particle or object moving at some velocity isn't going to experience a different gravitational "force" under the same curvature...

I saw this physics joke somewhere and didn't understand it. Could someone explain it to me? Don't be a d^3x/dt^3 Thanks!

As revealed by the CIA analysts they noticed that the suspicious house had no phone and Internet connections. Could Osama have a CELLULAR phone with Internet (registered for somebody living far away) and use it (for reception only) outside of any means of detection?? Many thanks for...

Can you please explain how to factorize x4+2x2+9 If i do it by quadratic formula, i get complex roots ... in my book, it has been factorized to (x2+2x+3)(x2-2x + 3)

I was bored last night and look at Wikipedia's article on Feynman when I saw this quote: http://en.wikipedia.org/wiki/Richard_feynman#Challenger_disaster (bottom of top paragraph) Can anyone put this into some context and explain what he was talking about?

Homework Statement Prove that the geometric series \sum_{n=1}^{\infty} r^n if -1 < r < 1 2. The Solution s_n = r + r^2 + ... + r^n rs_n =r^2 + r^3 ... + r^{n+1} s_n - rs_n = r - r^{n+1} s_n = \frac{r - r^{n+1}}{1 -r} For |r|<1 As\;n\to\infty\;,r^{n+1}\to \infty...

If anyone could help, that would be amazing. its not homework, its a personal project i am undertaking and just wondered if anyone could give me an explanation or any help if they had any understanding of this circuit! thanks guys! Samm

The question was: A solid cylinder or radius 10cm (.1m) and mass 12kg starts from rest and rolls without slipping a distance L=6m down a roof that is inclined at the angle 30 degrees. What is the angular speed of the cylinder about its center as it leaves the roof? Step 1: I got the...

Homework Statement explain why the vectors a=(-2,3) and b=(3,-1) = (13,9) how do i do this

Homework Statement Indicate whether sech(x) is invertible for [0, infinity) and explain why.The Attempt at a Solution Sooo... I know that: sech(x) = 2 / ( ex + e-x ) I know that to get the inverse equation I'd need to swap the y and the x... but I'm trying to show whether it's invertible...

Can someone explain Laplace transformations! i don't understand ittttt. [edit] sorry. i hadnt even heard of laplace transformations until i found it in my assignment. basically i want to know how to use them so, some simple, well explained examples perhaps?

I work in a laser lab and I'm constantly hearing about electronic components that I don't understand (my background is materials science). This is one example. Could someone either explain or point me to an introductory level reference on what a discriminator is in the context of light...

So I understand local realism (the moon is there when we aren't seeing it) and the notion that Bell's Theorem says that if local realism is true, then we could perform experiments that show observation is independent of reality and that we should expect certain probabilities to arise. But we...

Please explain Euler's theorem. :cry: I don't get how he got this formula and how it can be used instead of trigonometry. Thanks :confused:

can anyone explain Fresnels equations to me ?? Hi members I am undergraduate student , this term I study optics course but there are some things I don't understand it as Fresnels equations ! can anyone explain Fresnels equations to me in details ?? or give me link take about...

Homework Statement The question pertains to hydrostatic lifts. So, assuming you have a lift and you're applying pressure to one side and the other side is rising: P0 + P1 = P0 + P2 + (rho)gh Now, when we look at the equation, why is it (rho)gh? I'm thinking it's something like mgh, so to...

Do you ever get asked to explain concepts of physics in your offline life? Do you find it difficult or easy to explain topics when the person will not listen to a single piece of maths? At this stage if anyone with zero background of maths asks me something I have to promise to email...

The very likely explanation of the apparent Pioneer anomaly through improved heat radiation models (https://www.physicsforums.com/showthread.php?t=486509". As luck would have it, just today I stumble upon an article on improved measurements of the Earth's gravitational field by the...

Explain this MIT problem?? Homework Statement http://web.mit.edu/course/8/8.02-esg/Spring03/www/8.02pset9sol.pdf Problem 4 31-9 Why are they using x for the B-field? Isn't the distance from the rod to the loop h + w?? I don't understand on step 4.2

Explain how an atom may have a permanent magnetic dipole moment? Many thanks...