Einstein Definition and 788 Threads

Homework Statement I have E(v) = (m*c^2)/sqrt(1-v^2/c^2). I also have a second-order Taylor-polynomial around v = 0, T_2_E, which is mc^2+½mv^2. I have to use Taylors formula with restterm to show that E is bigger than T_2_E for all v in the interval [0,c). The Attempt at a Solution...

Hi all, In my last thread on phonons and aether, I was prompted to look up some stuff of modern aether. I will leave it up to you to interpret as i know little of this, but basically, there are a few guys out there there that firstly think Einstein and others are wrong with relativity etc...

I have E(v) = (mc^2)/(sqrt(1-(v^2/c^2)). I have found the second-order Taylor-polynomial for v=0, and I get: T_2_E(v) = mc^2 + ½mv^2. My teacher asks me, why this equation must be true - what is so special about the second order Taylor-polynomial for v = 0 for E(v)?

Can anyone tell me how far cosmology has advanced beyond Enstein?

Homework Statement I am a bit new to Einstein notation. Why is this true: \eta_{\mu \nu} \frac{d \delta x ^ {\mu}}{d \tau} \frac{d x ^ {\nu}}{d \tau} = \frac{d \delta x ^ {\mu}}{d \tau} \frac{d x _ {\nu}}{d \tau} How can you go from 16 terms on the LHS to just 4 terms on the RHS. If it is...

Hello, As with a lot of people, I have been excited and fascinated by the field equations Einstein described, revealing the curvature of spacetime. I would like to create a computer simulation which simulates the effects of the Einstein Field Equations, in other words, the curvature of...

Car 1 is traveling at 3/4c. Car 2 in behind Car 1 is traveling at 1/2c. Car2 fires a bullet that travels at 1/3 c. OK. In order to determine whether the bullet reaches Car 1 or not we need to use Einsteins velocity addition rule and determine whether the relative velocity of the bullet...

A few questions about BEC: A) When these bosons condensate, many particles fill the ground state. I read from textbooks that this would imply that they occupy the same position. -1- experiments are done with Rb atoms, which consist of protons, neutrons and electrons. Wouldn't the electrons...

http://arxiv.org/abs/0706.4400 Albert Einstein - a Pious Atheist V. Djokovic, P. Grujic 21 pages (Submitted on 29 Jun 2007) "We consider Einstein's attitude with regard to religion both from sociological and epistemological points of view. An attempt to put it into a wider...

if we consider the Group structure of [ \pi _{ij} , g_{ab}]= \delta _{ia,jb} of the Einstein equation for the momenta and metric, could we obtain its Casimir Operator, conserved quantities and so on?

what y'all think about that portuguese guy (joão magueijo) and his colleagues who have proposed that the speed of light has varied since the big bang (it has slowed down according to this new stream)...do you agree with this?

On this site http://www.geocities.com/physics_world/mass_paper.pdf It states that the 3 force can be written as... F = M1 x A1 + M2 x A2 Where 1 is the longitudinal component of acceleration and 2 is the transverse component of acceleration. It appears that if there is no...

Was Einstein Wrong? In Chapter 9, The Relativity of Simultaneity, of Einstein’s book Relativity (http://www.marxists.org/reference/archive/einstein/works/1910s/relative/index.htm), Einstein said: “Hence the observer will see the beam of light emitted from B earlier than he will see that...

The New York Review of Books got Lee Smolin to do a 10-page review of a handful of recent Einstein books. It's definitely stereoscopic (3D). with a sense of the complex personality. nice to see the oversimplified popular images countered http://www.nybooks.com/articles/20279 Mark Trodden of...

The Einstein cross (G2237+030) shows 4 reasonably symmetrically spaced images of the very distant quasar, indicating that our alignment with the galactic nucleus to quasar line is fairly good. How is that it does not show an Einstein ring instead of the cross?

Please help to find the answer of this question.

Can someone explain to me why this is the appropriate action?It makes some sens that that would be used, but I'd like a detailed explanation from someone familiar with the topic. Why is it the one that yields the proper equations?

Hey, Can anyone help me to understand einstein notation and permutations? I have a book, but it's not very clear. I really don't understand how you can write A_ij = e_ijk a_k out as a matrix? To start with I understand that a matrix can be represented as A_ij where i is the row and j is the...

Einstien was a brilliant scientist and he made great advances in our understanding of the world around us. His theories are works of beauty (what I understand of them anyway), but other than that, what really is the big deal? There are documentaries on his life. He had the kind of celebrity...

I do not understand Einstein's thought experiment explaining special relativity. If I understand it correctly, you have two people. One is on the center of a moving train, and the other is on the ground next to the tracks. As the one on the train and the observer pass each other, lightning...

Matt Visser - Lorentzian wormholes. From Einstein to Hawking (Springer) (1996) Just opened this book. Does anybody know it, and if you do, do you recommend it? Any feedback on this book.

Can someone explain to me what Einstein Hilbert action is? and how it relates to the variational principle? I appreciate any help that I can get!

Einstein views on gravitation,please. help! Hi all, If someone may explain in simplest manner the views of Einstein on gravitation?.Particularly I'm much confused about 'geodesics' & 'curved space time'.Thanks.

Has anyone evaluated the Einstein Field Equation purely in partial derivatives wrt x,y,z,t? What does it look like?

In Landau's bok "Classical Field Theory" pages: 372-373-374 they manage to get the Einstein-Hilbert action (after integrating by parts and use divergence theorem) \mathcal L = \int dx^{4} \sqrt (-g) g^{ik}(\Gamma^{m}_{il}\Gamma^{l}_{km}-\Gamma^{l}_{ik}\Gamma^{m}_{lm}) from this and...

The Einstein field equation relates the curvature of space to the distribution of matter, representing the latter with a tensor T. The components of this tensor have been interpreted as representing the volume-density of mass-energy together with the "pressure" in each spatial direction. Can...

Einstein was wrong, and should be Cartanized! (:D this is professional research) that's what I get from Derek's paper----classical 1915 Gen Rel is wrong because it uses a vintage 1850s manifold which has flat tangent spaces that don't roll. It should be moved over and put on a Cartan manifold...

Ref: http://en.wikipedia.org/wiki/Principle_of_locality" I don't have this article, so my first request is that if anyone has it and can either post it or (if concerned about copyright issues) you could email it to me, that would be appreciated. I may need it as a reference for a paper I'm...

Light on math, heavy on the man. Strangely, a search of these forums revealed no topics dedicated to this question. It would be swell to put yer thoughts in one place for me or anyone. What would you recommend? THANKS!

I'm reading a text on tensor analysis (on R³), and I don't understand the following exemple... P=\frac{1}{2}(a_{ij}+a_{ji})x_ix_j=\frac{1}{2}(a_{ij}x_ix_j+a_{ij}x_jx_i)=a_{ij}x_ix_j To pass from the second to the last equality, he commuted the second pair of x_jx_i into x_ix_j. But he...

If you can derive the Eisntein equations from: L=\int_{V} d^{4}x\sqrt (-g)R but does L has a potential term so we can do Qm with it?..:confused: :confused:

The constancy of the speed of ligth is a result of the Maxwell's equations. And the Lorentz transformation is an invariance of Maxwell's theory that was known before the special theory of relativity was discovered. Why and how did the physics of the 19th century (particularly Maxwell) built...

Recently, I have realized how much did Einstein contributed, indirectly, to the field of QM. I mean, using his two famous relations E=mc^2 (relativity) and E=hf (photoelectric effect), we derived the relation p = \frac{h}{\lambda}. Then, by the help of a keen insight from de Broglie, we...

That is, why did he use signals whose speed is invariant?

In "Frozen Light" an article written by Lene Vestegaard Hau, it talks about Lene's experiments with, literally, slowing down light by way of passing it through "ultra-cold clouds of atoms." The experiment was undertaken at Cambridge and Lene and a group of researchers were able to get light's...

[PLAIN][/URL] marlon

Just wondered if anyone had any good links or recommended books on Einstein's unification theory. I've tried searching the web but usually all that pops up was that his theory was a failure. My interest is where exactly he went wrong & perhaps even some of his mathematics. I figure the...

If we have the Einstein Lagrangian... L= \sqrt (-g)R my question is how do you get the Hamiltonian?..the approach by Wheeler-De Witt is to consider the line element: ds^2 = N(t)dt^^2 + g_ij dx^i dz^ j (Einstein sum convention) and then substitute it into the Lagrangian above and perform...

This issue came up in a recent thread and I recall that it came up in another thread about a year ago. I think it deserves its own thread. If it already has one and you know of it, please direct me to it. Does acceptance of Einstein's theory entail rejection of Newton's? On page 98 of...

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Dear friends, I have asked the following question before, but I am not still satisfied with the answer given by the experts of this forum. In Einstein equation E=m/c2 ¿ Does E equal to the thermodynamic internal energy of matter plus kinetic energy plus potential energy of a system?. ¿...

...had taken up the offer of becoming president of Israel in 1952, would things have been different? I think so. Imagine, he could do some theoretorising on higher dimensions, finding a way in which space could be inhabited by both parties at the same time... Of course, this wouldn't be...

Who is more important for Physics World, Newton or Einstein? And why? Who do you think is more intelligent based on each one's contributions to science and level of difficulty they discovered?

http://www.scienceagogo.com/news/19980907140525data_trunc_sys.shtml :smile: That's strange.

are there any posters of both Albert einstein and neils bohr? being two of the greatest minds of the 20th century, and the dichotomy between them... i think the poster would say a lot. plus, einstein is my favorite physicist. so, if you know of any, id like to buy one. thanks!

hi! i have a question. can you help me answer it? i have studied physics about the equation E=mc^2. i know that everybody who studying physics know it. can some body show me how he got there? what maths mean that he used to reach that? i wonder if it is really complex? thanks!

http://arxiv.org/PS_cache/gr-qc/pdf/0505/0505099.pdf Franklin Felber says in this paper that for the first time has obtained the solution of the orbits of a particle near an ultrarelativistic central field (in second order of aproximation). This leads to the gravitomagnetic...

Hello, I am trying to teach myself quantum mechanics so take it easy on me. In 1905, Einstein proposed that light is made of photons and that each photon carries energy E = hf (f is frequency) and momentum p = h/w (where w is wavelength) My question is how did he go from the...

What do you guys think of this site? http://www.relativitychallenge.com/mistakes.htm" Is there anything to this?

The famous Einstein quiz: Einstein said that 98% of the people in the world cannot solve his riddle. Facts: 1: There are 5 houses in 5 different colors 2: In each house lives a person with a different nationality. 3: These 5 owners drink a certain beverage, smoke a certain brand of...