Einstein Definition and 788 Threads

When Einstein spent the last years of his lofe looking for a theory of everything, what was he looking for? Was he looking for a single equation to sum up all things in the universe? Or a set of rules? Or was he just trying to find something in common with the very small and the very big?

Hi! I want to write the following expression in Einstein notation: (a_1+\ldots+a_n)(b_1+\ldots+b_n) I tried it by introducing the term I^{ij}=1 and writing: a_ib_jI^{ij} Are you aware of another, more convenient form for this?

Hi there, I have a few queries and they are as follows: (i) What is the difference between the Einstein metric and the Space-time metric? (ii) What does the curvature of the metric really mean? Does one calculate the Riemann curvature tensor, but what does that really tell you if it...

An article in Wired concerning a new atomic clock has as part of its lead sentence "The new timekeeper could one day ... detect the slowing of time predicted by Einstein’s theory of general relativity." See http://www.wired.com/wiredscience/2010/02/quantum-logic-atomic-clock/#ixzz0f1IPhJLR...

"Cranks" vs Einstein I see a lot of stuff on the internet from people that some would call "cranks", disputing SRT etc. (Personally, I try very hard to keep an open mind.) My question regards the fact that I have never yet seen any of those "cranks" directly discuss or dispute Einstein's...

So, all I ever keep reading is that virtual particles don't HAVE to satisfy E2 = p2 + m2. Should it instead be that they don't satisfy the energy relation. Also, can someone show the general case mathematically how the energy relation is violated. If it's easier maybe a simple example of an...

Schwarzschild metric: c^{2} d\tau^{2} = e^{\nu(r)} dt^{2} - e^{\lambda(r)} dr^{2} - r^2 d\theta^{2} - r^2 \sin^2 \theta d\phi^2 According to reference 1, the Maple 13 'tensor' package generated this solution for the G_{11}[/tex] component: G_{11} = \frac{- r \nu' + e^{\lambda} - 1}{r^2}...

Hello... I have heard that the speed of light is 300,000km/s. Planks constant is another number and so on and so on and so on. Alot of these numbers seem to be very 'arbitrary' figures... Is there a subject in physics called "parameter" analysis where the various arbitrary numbers and...

The most recent version of the theorem, as stated by Nikonorov in 2004 Let G a connected compact semisimple Lie group, which acts almost effectively on a seven-dimensional simply-connected homogeneous space M^7=G/H. If (G/H,\rho) is a homogeneous Einstein manifold, then it is either a symmetric...

Dear everyone can anyone help me with the euler lagrange equation which is stated in d'inverno chapter 11? in equation (11.26) it is said that when we use the hilbert-einstein lagrangian we can have: ∂L/(∂g_(ab,cd) )=(g^(-1/2) )[(1/2)(g^ac g^bd+g^ad g^bc )-g^ab g^cd ] haw can we derive...

Hello friends, I am now interested in Einstein scalar field equations with a very little knowledge about Physics. I would like to ask why vacuum Einstein equations are hyperbolic equations? As far as I know that for 3+1-dimensional manifold V, we can convert the vacuum Einstein equations as a...

show that in the thermodynamic limit the bose gas condensate does not contribute to pressure for ideal bose gas in volume V with N particles.and physically explain. how to get it start?and what will b its physicsl explanation? kindly reply soooooooooooon

In http://www.bartleby.com/173/12.html" Einstein says the following: But what is he saying here? That 1 proper second in the reference frame K is equal to gamma proper seconds in the moving frame K0, leading to the conclusion that the seconds in K are larger than the seconds in K0 and...

Having a Lorentzian 4-manifold, the Einstein vacuum equations of general relativity read \overline R_{\alpha \beta} - \frac{1}{2}\overline g_{\alpha\beta}\overline R=0 where \overline R the scalar curvature, \overline g_{\alpha\beta} the metric tensor and \overline R_{\alpha\beta} the Ricci...

Homework Statement In the Einstein model of a particular solid, one quantum of vibrational energy is ΔE=0.050 eV. This means an energy equal to ΔE is needed to raise an oscillator from one energy level to the next highest level. Assume this solid is at room temperature. What is the...

As a layman, I'm having a problem with understanding the search at LHC for the Higgs Boson. As I understand Einstein, all mass is nothing but energy. In that case, why are we looking for a particle which imbues mass? For example, in Rutherford's experiment, at least in my mind's eye, when...

I'm just getting a taste of computational GR, and I have a question regarding the metric for the single point mass solution for the einstein equation. The metric in spherical coordinates for a point mass at r=0 is \eta=\left(\begin{matrix}-\left(1-\frac{2GM}{c^2r}\right) & 0 & 0 & 0 \\ 0 &...

I'm reading GR on http://www.bartleby.com/173/29.html" quoting "Hereupon we introduce a hypothesis: that the influence of the gravitational field on measuring-rods, clocks and freely-moving material points continues to take place according to the same laws, even in the case when the...

I was reading about Eisteins theories and had a question. If light can not escape the gravitational pull of a black hole, then assuming that the black hole accelerates (at a constant acceleration) all matter and energy into its event horizon, then if the gravitational pull overcomes the speed...

Can a photon gas undergo a Bose Einstein condensation ?

Can any 1 tell me what is the derivation for worm holes(equation)?

Hi i tried in the other section with no luck. Let me try here if there are anyone here that can help me. the question is: Suppose one catches in 5000-Na atoms in a spherical-shaped cloud with diameter of 2mm. And suppose that the atoms are uniformly distributed in that sphere. At what...

I don't know if it has been asked before - if so, I'm sorry :) I was just sitting and thinking. Are there any "Einsteins" alive here in 2009 ? I mean... 100 years ago you had Newton who came up with the laws for mechanics, then you had Maxwell who came up with the laws of electrmagnetism...

The quote “The only reason for time is so that everything doesn't happen at once” is attributed both to A. Einstein and Woody Allen. Does anyone know which one is the true source?

An interesting question maybe, but only in so far as the equations: y' = y and z' = z are concerned. In http://www.bartleby.com/173/11.html" Einstein demonstates that if x= ct then x' = ct' in which he is absolutely correct, but if one were to try and do the same for y' and z' the result...

Homework Statement Using the Einstein summation convention, prove: A\bulletB\timesC = C\bulletA\timesB Homework Equations The Attempt at a Solution I tried to follow an example from my notes, but I don't entirely understand it. Would it be possible to find out if what I've...

Homework Statement Evaluate the following sums, implied according to the Einstein Summation Convention. \begin{array}{l} \delta _{ii} = \\ \varepsilon _{12j} \delta _{j3} = \\ \varepsilon _{12k} \delta _{1k} = \\ \varepsilon _{1jj} = \\ \end{array} The Attempt at a...

didn't time dilation concept known before einstein relativity theory? there were ancient story saying that time runs differently on different planes of existence. i will relate one of ancient hindu mythology in which time dilation was referred. Story of King Kakudmi and his lovely...

Okay, I have heard that Albert Einstein wasn't really into this whole idea of quantum mechanics. What was some of the reasons for this?

Homework Statement Plot the heat capacity as a function of temperature for aluminium, using the Einstein model. Homework Equations The Einstein model for heat capacity: The Attempt at a Solution The model assumes that the frequencies of all the harmonic oscillators in the material are...

Rencently, I found myself confused by some fundamental concepts in GR. I hope someone can help me with that. We all know the vacuum Einstein equation (VEE) without the cosmological constant \Lambda is Rab=0. Since I learn GR the words " matters bend the spacetime " been told again and...

Hi, I have recently been delving into Quantum gravity related material... and I came across a paper by Ted Jacobson "Thermodynamics of Spacetime: The Einstein Equation of State" http://arxiv.org/abs/gr-qc/9504004 and as far as I understand the argument it is very impressive who would have...

Hi, i have read a introduction book to general relativity and i want to ask a question: how do physicists use the Einstein equation to solve problems? I mean how can we, starting with a given energy-momentum tensor, find the metric? Thanks!

I've only just begun reading about relativity, and am finding Einstein's popular level book "Relativity: The Special and General Theory" quite satisfying. This particular example, from Section X (ON THE RELATIVITY OF THE CONCEPTION OF DISTANCE) has me a bit confused, though: 1 [SIZE="2"]the...

From what I'm reading, Xj = aijXi (X is a vector and the subscript for a is i)...though I'm not sure where the aijXi came from. Would this by any chance be a relation for the transformation equations from Xj to Xi?

What is Einstein temperature? I know how to calculate it but I don't understard what it means...

Can someone explain the equation G_{\mu\nu}+\Lambda g_ {\mulnu}={8\ pi G\over c^4} T_{\mu\nu}\ by Albert Einstein?

I was wondering why Einstein picked C for this equation. C is just one spot on the energy spectrum, the high end of which we are probably not yet aware. A nuclear explosion, for example, produces energy in the full range, sound, microwave, radio, etc., (we assigned names for identifying...

Homework Statement Hi, I need to know the correct SI units for Einstein Coefficients (A and B) for stimulated emission (say laser). The equation I'm on about is Homework Equations \frac{A}{B} = \frac{8\pi h\nu^{3}}{c^{3}}The Attempt at a Solution after some scribbling I got to \frac{A}{B}...

I'm wondering if there are any good programs to calculate the various tensors that one needs to solve the Einstein field equations for a very general metric i.e. metric components are not specified explicitly, only their functional dependence on the coordinates e.g. ds^2=-n^2(\tau,y)d\tau^2 +...

If both Isaac Newton and Albert Einstein are still alive today, imagine the world we will be living in and the impact on all theories of physics! Can you imagine what the world will be like with them still around?

Hi everyone I need the historical articles that bose and fermi integrals were defined for the first time. Can anyone help me?

Before I begin, I stress that this is NOT a homework question but rather a self-study question. In any case, I calculated the Einstein Tensor of a body with the metric diag[{2GM/r-1,0,0,0},{0,1+2GM/r,0,0},{0,0,1+2GM/r,0},{0,0,0,1+2GM/r}]. What does the Einstein Tensor represent? Does its...

The following is the Einstein’s train but instead of train consider two airships of equal in lengths. http://www.youtube.com/watch?v=wteiuxyqtoM&feature=related Both are moving with same speed but opposite in direction. After certain time they cross each other such that one is exactly...

Gµv + Λgµv = (8πG/c4)Tµv I have several questions. what is the µv? when we use it today do we use the cosmological constant even though the universe isn't static or does it mean something different than einstein orignally thought? what are we measuring when we use this if theyre all constants?

i heard it was becuase it was to over the heads of the Committee is this true?

Subject: A Baffling Quote from Einstein, badly requiring explanation All sources I've consulted indicate that Einstein reconceived gravity in General Relativity by discarding the prevailing, intuitive, Newtonian view of it as a 'force' accelerating objects, and daringly envisioned it purely...

Homework Statement Show that the multiplicity of an Einstein solid with large N and q is \frac{\left(\frac{q+N}{q}\right)^q\left(\frac{q+N}{N}\right)^N}{\sqrt{2\pi q\left(q+N\right)/N}} Homework Equations N! \approx N^N e^{-N} \sqrt{2 \pi N} The Attempt at a Solution Well...

Although Albert Einstein had explained the new picture of gravity through his theory of general relativity, by explaining that gravity is the warping of spacetime, did he explain why mass actually warps this fabric of spacetime?

If I have a (1,1) tensor, eg a Lorentz transform, how do I write its inverse? For example: x'^\mu=\Lambda^\mu_\nu x^\nu Would I multiply on the left by: (\Lambda^{-1})^\nu_\mu? It seems to make sense, but I'm not 100% sure. I'd prefer to not use anything from matrix multiplication...