Einstein Definition and 809 Threads

Homework Statement First, let's derive the predictions for He-4 atoms at very low temps given the MB distr. Homework Equations The Attempt at a Solution Given the MB distr., if the ground state of the system is assumed to be at zero energy, then the ratio of occupation numbers...

Based on the wiki article: http://en.wikipedia.org/wiki/Einstein%E2%80%93Cartan_theory Cartan gravity is not just “possible extension” of GR, but it is absolutely necessary and unavoidable (search for “proof” in the article). As wiki is not a 100% trusted source, I wanted to ask: How...

I have two questions. Why did Einstein think the Universe was steady (unchanging)? What were his motives? And two: To make his universe steady (static) Einstein added the cosmological constant to his Theory of Relativity. Later he said that adding the cosmological constant was his...

So, I can't really find this limit: \lim_{T \to \infty} \ 3Nk {(\epsilon/kT)}^2 \frac{e^{(\epsilon/kT)}}{{(e^{(\epsilon/kT)}-1)}^2} This is actually the formula for the specific heat of an Einstein solid, which is pretty easy to derive but I haven't been able to calculate the limit to show it...

Einstein synchronization, as it is conventionally defined, depends on subtle issues like the one-way speed of light. But the slow transport of clocks produces the same simultaneity convention. And I would think that the slow transport convention is a tautology. After all, if time only changes...

So I am an engineering graduate trying to teach myself some general relativity. I have tried to solve the Einstein Field equations for a wormhole metric and some others. After pages and pages of calculating Christoffel Symbols, Riemann Tensors, Ricci Tensors and Scalars, and so on, I end...

For Minkowski spacetime, the metric is: ds^2 = -dt^2 + dx^2 + dy^2 + dz^2 I have read there is a solution when the time dimension is "rolled" into a cylinder forming a closed timelike curve. So the BC is t -> [0,T] with t = 0 identical with t = T. The Field Equation is: Rab - 1/2...

This has been bothering me for a while. In Einstein's original derivation of the Lorentz transformations, he finds... \epsilon=\frac{c^2}{c^2-v^2}x' Here, \epsilon is what we would normally call x', and x'=x-vt (sorry if that's a bit confusing). He then says, "Substituting for x' its...

Hi, I am just starting to learn vector algebra with Grad, Div, Curl etc and have in passing come across Einstein notation which seems to make things much more concise. The problem I have is in Finding Div(rn r) where r =xi + yj + zk. The unbold r is the magnitude of r. I have used...

Many popular-physics books mention that Einstein searched for a unified theory of all interactions, and that he failed in his research. However, they never say what exactly the Einstein ideas were (and why exactly these ideas didn't work). Does anybody know a source (in english) were more...

I asked this in one of my previous topics, but I just cannot find where I asked it, so here I am asking it again. Can someone give me a link to a web version of Einstein's GR. I want the one with Einstein's OWN WORDS, not reworded (other than simple language translation, if he did not write...

1. I can't understand one step in the derivation of the Einstein tensor from the Bianchi identity.I have looked in a lot of books and all over the internet and everyone glosses over the same point as if its obvious, but it isn't obvious to me. 2. Below is the entire derivation. It seems...

How did Einstein come to the conclusion that nothing can go faster than the speed of light? Did he base it on the failure of the Michelson-Morley Experiment to determine a difference in the speed of light based on the measurement?

1) What exactly does the metric tensor expand into? Since it describes general space-time, shouldn't it be more like a vector like R = √(x^2+y^2+z^2) Why even should we use tensors in relativity when we can just stick with vectors? 2) Are the equations all theoretical? Have they been...

1) Consider that one way light speed is anisotropic. 2) Use the Einstein method to synchronize all the watches by the watch located at (x,y,z)=(0,0,0). Now, all the watches are synchronized by the watch at (0,0,0) but they are not necessarily synchronized with each-other (Consider watches...

Hi ! I'm trying to understand the Dark matter problem, because it scares me if clever people tell me they don't know out of what 23% of the universum is consisting. But let's start with a simple question on GR: GR is stating that a body moving at a speed close to c holds an almost...

I'm reading Einstein's book on relativity (aptly named Relativity), and trying to follow his "simple" derivation of the Lorentz transformation in Appendix 1. However, since Einstein feels it acceptable to skip over important steps, it leaves me to figure them out, but I am lost on one step...

Suppose I am simple man, who studies in home and read some scientific journals . Could I be able to deliver some theories(and would it be possibly correct ?. Would I have to be engaged in big laboratories consiting super computers, advance telescopes etc? How was eeinstein became able to...

As many of you have already guessed I refer to Einstein and his famous quote that the only way to win at roulette will be to steal money from the casino...obviously meaning that you can't devise a mathematical strategy to beat roulette. Over the years of course some people have tried to beat the...

I just recently came across this idea, outlined in http://arxiv.org/abs/1005.3497" ). I've looked for some discussion here, but couldn't find any, so I thought I'd start one (if I missed some previous discussion, I'd appreciate a link). The basic idea is simple: to probe transplanckian...

After reading the Bad Nauheim debate (1920) between Albert Einstein and http://en.wikipedia.org/wiki/Philipp_Lenard" , there are three critical points raised by Lenard against relativity (see also the following descriptions of the debate by Hermann Weyl, Gehrcke, Körner)...

I have recently learned the basics special relativity and it is amazing!, but I still have a few questions and I will be thankful if one can answer me. (I will rather open an extra thread for each question that bothers me, so each question can be handled independently.) So I would like to...

When Albert Einstein published the general theory of relativity he predicted that light would bend. But before the measurement experiment was executed he changes that prediction. The last prediction was a factor 2 larger. So far I remember he claimed that this was because also the whole...

Three simple experiments put to question Einstein's Special Relativity interpretation. It has nothing to do with the formulas. Formulas work pretty well; the BIG problem is interpretation! 1.The most recent particle collisions at CERN: Two Proton Beams at 3.5 TeV, traveling in opposite...

Im currently reading Entanglement by Amir D. Aczel. It explains the arguments for and against quantum theory at the Solvay Conference in 1930. At the conference Einstein told Bohr that he could refute the uncertainty principle for energy and time. Einstein said he designed a box with an opening...

Hello all! I'm wracking my brain - I could swear I once read that Einstein had decided to have a bunch of his work sealed for 75 years after his death. Scientific work - not the personal letters that were sealed for 20 years. I can't find any reference to this on the web... Maybe it was...

I'm trying to understand the Einstein field equations conceptually, and one of the things that I'd like to understand is why Einstein decided that the left side of the GR equation should be the Einstein tensor instead of the Ricci tensor, I heard that initially he entertained the idea of...

Homework Statement Sketch all the possible microstates for an Einstein solid using dots to represents units of energy and lines to separate oscillators. In addition, identify all possible macrostates of the system. Let N=3 (oscillators) and q=3 (units of energy). Homework Equations...

Einstein Field Equations? I have not been able to comprehend the Einstein Field Equation, the Stress Energy Tensor, the Ricci Tensor, the Einstein Tensor, and Christoffel Symbols. Though I am reasonably proficient at working with nested loops in programming, and I have a rudimentary knowledge...

Found this quote years ago...can anyone help me understand it? I don't think it is out of context, just a bit vague to my pea brain. I think it can be found in more than one place; I might have gotten it from "Meaning of Relativity", but I loaned it and it's still out. Einstein on Space...

I am interested in pursuing the modernized redesign of the eistein refrgeration system. It is a refrigeration system using anhydrous ammonia, liquid butane, and water. It is contained in a closed pressurized system, has no moving parts or compressor, and requires no maintenance. Sounds like a...

I first learned of this paper in a FAQ by Benjamin Crowell which gave a link to Einstein's handwritten manuscript, but no English translation, so I had a go at making http://www.oe.eclipse.co.uk/nom/aether.htm . Some of the physics is above my head, especially the stuff on radiation and...

I have arrived at what appears to be a different equation(from Einstein's original work equation, W= mc^2(1/sqrt(1 − vt^2/c^2)+1). ) for the total energy of a particle of rest mass m,moving at speed Vt. My derivation using a universal 2D transformational model is as follows W =...

Hello, I am supposed to prove that the determinant of a second order tensor (a matrix) is equal to the following: det[A] = \frac{1}{6} \epsilon_{ijk} \epsilon_{pqr} A_{pi} A_{qj} A_{rk} anyone have any idea how i would go about this? any method is welcome where the determinant of the...

In the PBS documentary on Einstein's E=MC^2, the story makes it seem as if Planck called on Einstein in response to Einstein's paper on E=MC^2 which was published in 1905. But Einstein wrote an earlier paper on the photoelectric effect and the quantization of energy, also in 1905. Was it for...

Why should we trust the Reissner–Nordström solution of charged black holes? It relies on coupling between Einstein tensor and EM stress-energy tensor, which has NO experimental support whatsoever. Is there any chance we can test this?

So, is there a torsionon? I tried to sort out something, but the only thing I could find was paranormal stuff, unfortunately. So, I at least I came up with this, although no mention to torsion as a particle: http://arxiv.org/abs/gr-qc/0505081 (equation 4) Physical effects of the Immirzi...

Hi, In attempt to understand SR, a moving mirror clock is often given as part of a thought experiment, which leads to the dismissal of absolute time. To save people reading, the short version of my question is this: This experiment assumes light is wave-like, right? The long version of...

What was the conflict between Newton and Einstein? what they division Classical and Modern Physics after after theory of relativity?

Hi, I'm rather confused about the procedure in which people obtain gravity from gauged (super)-Poincare algebras. Let me outline what this procedure is. *First you gauge the Poincare algebra with generators P and M *You obtain two gauge fields: the vielbein (associated with P) and the...

i've heard several teachers talk about ideas being ripe at certain times, and while we often attribute amazing progress to certain individuals, really, the scientific community at large was pretty close to the results. Newton/leibniz, for example. one teacher talked about how archimedes was...

So my grade 12 physics teacher asked our class this question which he didn't have an answer to. Suppose I am in a spaceship traveling at 0.9c around the Earth. Because of time dilation, let's say 50 years (relative to me) have passed. Let's also say, for simplicity, that 100 years have...

Could somebody explain me what conformally flat is? How to prove a 2D geometry as conformally flat, for example: ds^2 = \phi(dx^2-dy^2) ; phi(x,y) What is class of Einstein Geometry? How to classify Einstein Geometry in 2D?

"Everything should be made as simple as possible, but not simpler" What I understood is we should not improve the old things, instead we should find an entirely new and easier way of doing the same thing. Does he mean that progress should not be made step by step like improving the age old...

Hello My name is Peter I know that so far some couple of people manage to make a Bose -Einstein condensate from a metal and from hydrogen, I would like to ask your opinion about what do you believe will happen if not the full atom will be brought to the Bose Einstein condensate state or...

I can't help but think that e=mc2 has a flaw. One mass is not defined to its simplest form and the speed of light has no vector accounted for. Any thoughts about this?

Homework Statement Ok so I'm meant to answer: To what scalar or vector quantities do the following expressions in suffix notation correspond? (expand and sum where possible). 1) aibjci 2) aibjcjdi 3) dijaiaj 4) dijdij 5) eijkaibk 6)eijkdij Homework Equations The...

I thought that when you used a roman letter such as v that you started at 1 instead of 0. For instance if you had: A^v C_{\mu v} Wouldn't that just be: A^1C_{\mu 1} + A^2C_{\mu 2} + A^3C_{\mu 3} ? (this is one of the problems with a solution from Schutz's book and the solution starts...

I have been reading over the two theories, and cannot figure out what Einstein meant when he termed something a 'mollusc'. Can someone please explain?

Hello I am looking for a certain paper by Albert Einstein (sometime between 1905 and 1920), where Einstein discusses Entropy - in this paper, he presents entropy, but then says that the term in the exponential or logarithm (cant remember which) need to be dimensionless. So he divides the term...