Curved space Definition and 80 Threads

I understand some of the basic concepts of curved space, flat, positive, negative, spheres, saddles, etc. In flat space, if one measures the angles of a triangle, the sum adds to 180 degrees. In spherical space, the sum is greater than 180. OK, how do things work in spherical space? If I...

According to the Equivalence Principal, the effects of Gravity are locally indistinguishable from those of Acceleration. QUESTION: Since Gravity curves Space, a la the Flamm Paraboloid, does acceleration do the same ? Acceleration does impose a comparable Time Dilation effect, from the...

In curved space, can I raise an index on a tensor that is being differentiated? Ie, is the following true? g^{\mu\lambda}\partial^\nu(F_{\mu\nu})=\partial^\nu(F^\lambda_\nu)

I have become very interested in physics and astronomy recently and have started dabbling. I have been reading about curved space time and its association with gravity. I've also been reading about time as it is related to travel at the speed of light. Can anyone explain the concept of...

in diffeomorphism invariant theory, which is the meaning of the time in quantization? or in other words which is the right time for quantization?

1.a) Concider the 2-space consisting of a spherical shell at constan radius, r. In polar coordinates the line element on the surface can be written (a, b,∈ 1,2) Homework Equations ds2=gabdxadxb=r2dθ2+sin2θdφ2 calculate gab, Γabc, R1212, R2121, R11, R22, R The Attempt at a Solution...

It is just something i can't get my head around, how to picture how space is curved around large masses. Is space like uniform jelly with it being denser around the planets, or is it like a void where curvature flattens out the farther away from the gravity source. Id like to hear your...

Many of the formulas of physics assume a background of flat spacetime. But it's natural to think that this is just a special case of a more general formulation in curved spacetimes. So I'd like to develop a general procedure to transform flat space formulas and integrals, etc, into their curved...

[SOLVED] Area of curved space Homework Statement I have the following metric, which describes a 2D, positive curved space with flat geometry (ie. a sphere): ds^2\,=\,dr^2\,+\,R^2 \sin ^2 (r/R)d\theta ^2 Here ds is the distance between two points (r, theta) and (r + dr...

[SOLVED] Prove: Sum of angles > 180 in curved space Homework Statement If I have a positively curved space (i.e. a sphere) and I draw a triangle on it, the sum of the angles of the triangle exceed \pi, more precisely, v1 + v2 + v3 = pi + A/R^2 where v1, v2 and v3 are the angles of...

[SOLVED] Topology of curved space Homework Statement The distance between a point (r, theta) and a nearby point (r + dr, theta + d\theta) on a positively curved sphere is given by ds^2 = dr^2 + R^2 \sin ^2 (r/R)d\theta ^2 NOTE: I mean that ds^2 = (ds^2). My question is - how do I...

Hi, i just found this forum when trying to find an answer to a question. I am not a physicist, not even close, I'm in high school still. Anyway, i will try to explain my question the best i can. It would be a lot easier if i could draw it but alas i can not... I am trying to conceptualize...

The GR equ. tells us that a test particle will follow a geodesic line in spacetime, which is not a geodesic line in space. Usually space is flat, but that does not imply the geodesic line of a test particle in space is a straight line (right?). Since if I throw a ball the gravity of Earth makes...

Is there a general procedure to convert or transform a function that is defined on a flat space into an equivalent function in curves spaces?

JesseM wrote Light doesn't need to have mass to be affected by a black hole, since in general relativity you can explain the motion of light in terms of the the black hole curving spacetime, and light following a geodesic path in this curved spacetime. I replied as matter is...

Hi there: i have a question on geodesics in a Eculidean space equipped with a metric tensor \lambda(x)*I, where I is the identity matrix. Is any general statement that can be made towards the geodesic between two points in this modified space? My feel is that this space is quite special...

http://arxiv.org/PS_cache/arxiv/pdf/0706/0706.3239v1.pdf Black hole entropy, curved space and monsters Stephen D. H. Hsu and David Reeb 21 June 2007 Almost all of the entropy of a given black hole must result from a smaller black hole which has absorbed some additional mass. It is also...

If i have a volleyball and draw a circle around the centre, then draw a line between the top of the ball and the centre and measure the two line I find that the ratio circumference of the circle to diameter of the circles is 4, thus implying that in this case pi is 4, however if I drew a circle...

The GR equ. tells us that a test particle will follow a geodesic line in spacetime, which is not a geodesic line in space. Usually space is flat, but that does not imply the geodesic line of a test particle in space is a straight line (right?). Since if I throw a ball the gravity of Earth makes...

In trying to understand why matter curves space i thought up a model that has the curiosity of suggesting the concept of maximum gravity, suggesting that as the mass of an object increases gravity increases as well, until the mass reaches a point at which the gravity starts to increase more...

For a beginner (as I am since a long time), it is convenient to conceptualize curved spaces as embedded within a familar flat space with more dimensions. Of course the intrinsic point of view is more elegant and suffice to itself. Nevertheles, I am asking this question: are there some curved...

I want to start a discussion about black holes and curved space. From what i know (not including that article posted in another thread) black holes are created when stars can no longer burn and compress so much that it creates a gravitational pull that is so big even its own light can't evade...

The parabolic approximation was introduced by Leontovich and Fock in 1946 to describe the propagation of the electromagnetic waves in the Earth atmosphera (see Levy M. Parabolic equation methods for electromagnetic wave propagation, 2000). However, the parabolic equation was known long before...

I have some question that might be hard for me to phrase clearly, but I'm going to give it a try. So, as far as I understand it, according to GR gravity is a side effect of the way mass (or mass energy, or whatever) curves space-time. So that when an object "falls" to the Earth, it isn't...

I have sort of a vague question. Am I right in saying that only mass and not energy cause space to curve and have gravitational effects (and other affects that only depend on mass)? Or does the "relativistic mass" of a photon cause similar but reduced effects? That's sort of just a lead in...

Have I got it right this time? Red-shifting is determined by the difference between the space-time curvature at the light source and the observer's space-time curvature. For the light source, all that matters is the distance from the center of gravity -- I think the motion of the source...

if mass curves the space around it is mass perhaps curved space itself?

According to General Relativity, the presence of mass curves space, and this curvature causes the effects of "gravity". Do Einstein's equations give us a clue as to the mechanism by which mass is able to do this? In other words, how does mass curve space? How does it "know" to curve space? And...

gravity caused by curved spacetime - am I right? I went over this with someone here a while ago and I think they became exhausted with me. Anyway, I went away to think about it. Here is what I have so far. I was told that gravity is caused by warped space time (according to, is it GR or...

One of the things Astronomers get flak for is presuming that the universe is curved (or more precisely, their model permits the universe to curve). People think astronomers are losing touch by using these horribly abstract mathematical ideas that obviously can have no connection to physical...