Singularity Definition and 422 Threads

For a physical singularity I think it is sufficient that anyone scalar quantity blows up, Why is it not a necessary condition that all blow up? For a curvature singularity am I correct in thinking that it is a sufficient condition to find a coordinate system in which the metric coefficient no...

Question TO: Physics Forums – March 17, 2015 Various sources I have read talk about the big bang origin as a point singularity. Here is one example:

considering the Earth as a sphere, at the centre of the earth, by the equation F = G*m1*m2/r^2 , the gravitational pull experienced would be infinite . so assuming that we built a tunnel from 2 ends of the Earth through the centre, and a person jumps into the tunnel. till the centre of the...

I'm curious about what others think. As I believe that you fall indefinitely in a black hole, and since you don't feel the gravity when falling, you fall until your incinerated by faster moving electromagnetic radiation falling on you. But you can only see what is above you, assuming your eyes...

If the Singularity Has Infinite Mass, How Does Merging With Another Black Hole Create "Suoermassive" Black Holes? Infinite Plus Infinite Is Infinite. No Increase.

Hello everyone! I'm having some troubles when I try to solve improper integrals exercises that have singularities on the real axis. I have made a lot of exercises where singularities are inside a semicircle in the upper half side, but I don't know how to solve them when the singularities are on...

Can a singularity expand in volume?

Hi guys, Is it right to say that a simple pole (pole of order 1) is a removable singularity (and vice versa)?

Just a quick question. How big was the current observable universe at the point in time where we reach 'singularity conditions' in the early universe? I'm assuming it can't be a single point, as there is no way that I know of to make a zero-dimensional point into a 3-dimensional object or space.

Hey Guys, so i was reading Hawking&Ellis a bit and still encounter always problems with the Penrose-Diagrams. Looking at the Penrose-Diagram for the rotating Kerr-Black hole (just one illustrating picture at the end) i come up the following question: Why are there TWO regions III and III ? In...

I have been pondering black holes for some time and have had trouble with the problems presented simply because there is very little we can do to study the phenomena. I have always thought of a black from the outside looking in, or basically the only way we can hope to see a black hole. However...

I have a problem with the concept of a singularity, defined as something that has a property which is infinite. Infinities do not belong in our reality, and in my opinion are just hints that our understanding of the phenomenon is incomplete or wrong. From my understanding, during the collapse...

Information that is ordered can be compacted down to a single repeating unit i,e; 110055110055110055110055 down to just 110055 and this meant that it must have been highly ordered to be compacted down this far. So could it be that matter is also highly ordered somehow and it can be compacted...

From Unger and Smolin's new The Singular Universe and the Reality of Time: A Proposal in Natural Philosophy, e-book page 403/576 "It is important to dispel some false impressions about the cosmological singularity theorems which are widely spread due to misleading accounts in some...

I always wanted to create a toolbox of critical analysis tools for young people to analyze, debate, and anticipate the near term future given our human nature and our history, especially since the scientific revolution. This is what my novel is intended to do, but writing a first (crap) edition...

Could the mass of a singularity be described or defined as an empty set, or else what is the term to describe it (in at least one sentence).

I just saw The Theory of Everything, which is a Hollywood biopic about Stephen Hawking. Of course the physics content had to be watered down and made to serve dramatic and thematic purposes, but a couple of historical points seemed interesting and made me wonder whether they were real: 1...

Consider a flat Robertson-Walker metric. When we say that there is a singularity at $$t=0$$ Clearly it is a coordinate dependent statement. So it is a "candidate" singularity. In principle there is "another coordinate system" in which the corresponding metric has no singularity as we...

How exactly would one show that [z^(c-1)]/[exp(z)-1]has a removable singularity at z=0? I tried using the methods introduced in my complex analysis book, but nothing seemed to work. Thanks!

Homework Statement Determine the points for which ##f(z) = \frac{z^2 + 3}{(z-3)^2(z^2 - 4z + 5)}## is analytic and singular. Homework Equations Theorem 133: Suppose c is a complex constant and suppose the derivatives of the complex functions f and g exist at z. Then 1. Sums ##\frac{d}{dz}...

Much has been said about the universe expanding from a point of singularity (POS). But why can't the POS be a shell of singularity (SOS) such that the expansion would take place inside the SOS without breaking it. Did anybody thought about that?

I know it is very unlikely such thing exists because QM can prevent CTLs However, what observer would see near such singularity? As ring is timelike, for an observer it won't be a ring at all, but a point, correct? That point should be visible (naked) because there are no horizons between an...

Homework Statement could someone explain why the terms in red represent the red distributed load in the attached diagram? Homework Equations http://postimg.org/image/3x0wywr4v/ The Attempt at a Solution the only term I think I understand is the -3<x-0>^0 but I'm not sure of the rest

I keep hearing that QM and GR don't play well together. For example, a singularity, a result of GR, is small enough for QM to apply but...it doesn't. I was hoping someone could explain exactly where the "equations fail." Unfortunately I'm so ignorant in this subject matter that I can't be...

Homework Statement Can someone explain how the expression for V(x) is plotted? Homework Equations The Attempt at a Solution I understand the plots for the dotted lines but not how they got the actual plot for V(x)

Homework Statement Given the function f(x_1,x_2) = (x_1 - x_2^2)(x_1 - px_2^2) where p is a constant parameter, for what value of p will the origin (0,0) be a singular point of this function? Homework Equations The Attempt at a Solution I thought that singular meant...

The Big Bang is often associated with the concept of a singularity. A singularity is defined as a point in space-time. A common interpretation is that the concept of a point is meant to capture the notion of a unique location in an Euclidean space. This seems to me very misleading in as much...

Hi, I am struggling for some time to solve the following integral: $$ \int_{-n}^{N-n} \left( \frac{e^{-j\pi(\alpha-1)\tau}}{\tau} - \frac{e^{-j\pi(\alpha+1)\tau}}{\tau} \right) d\tau $$ N is a positive integer, n is an integer, \alpha can be a negative or positive rational number. I want to...

Hello. Can you check this for me, please? Find the singularity of $\frac{e^{z^2}}{(1-z)^3}$ and find the residue for each singularity. My solution: There is a triple pole at z=i, therefore...

Hello. Can someone check if I got the answer right? $f(z)=\frac{e^{-2z}}{(z+1)^2}$ My solution: $f(z)=\frac{e^{-2z}}{(z+1)^2}$ $$Resf(z)_{|z=-1|}=\lim_{{z}\to{-1}}\frac{d}{dz}((z+1)^2\frac{e^{-2z}}{(z+1)^2})$$ $$\lim_{{z}\to{-1}}-2e^{-2z}=-2e^{2}$$

Hello. Can someone check if I got the answer right? Find the singularity and the residue. ##f(z)=\frac{e^{-2z}}{(z+1)^2}## My solution: ##f(z)=\frac{e^{-2z}}{(z+1)^2}## $$Resf(z)_{|z=-1|}=\lim_{{z}\to{-1}}\frac{d}{dz}((z+1)^2\frac{e^{-2z}}{(z+1)^2})$$...

Hello. I'm a layperson curious about physics. I've read that Quantum Gravity could eliminate the predicted singularity inside a black hole based on General Relativity. If that's true, what would happen from the frame of reference at the center of a black hole? Would that cause a tremendous...

Why, at the center of a black hole, does the need to be a point where space-time curvature is infinite? I understand that black holes scale with consumed matter, and that the point has 0 density but how do we get infinite G? I'm just an amateur but because this might just be a mathematical...

Homework Statement Hello, I'm having trouble understanding this, seemingly simple, concept. Any help or input is appreciated. Evaluate the following derivatives: $$\frac{d}{dt} u(t-1)u(t+1)$$ $$\frac{d}{dt} r(t-6)u(t-2)$$ $$\frac{d}{dt} sin(4t)u(t-3)$$Homework Equations The Attempt at a...

Although the subject line might seem to put this question inside general relativity, the reason I put it in quantum physics is because I would like to know what happens when one treats a singularity as a particle. Obviously from outside the event horizon, one cannot do this, but inside the event...

I am reading this paper http://arxiv.org/pdf/1111.4837.pdf and I came across under eq12 that the new metric is degenerate... How can someone see that from the metric's form? Degeneracy for a metric means that it has at least 2 same eigenvalues (but isn't that the same for the Minkowski metric...

"Cosmic inflation" and singularity Hi. I saw this on Wikipedia: http://en.wikipedia.org/wiki/Chronology_of_the_universe#Planck_epoch Later: If there was no "traditional Big Bang" with inflationary cosmology, would this remove the singularity at the beginning of the universe? If so...

Hi, everybody. I have the question about initial, gravitational big bang singularity. My first question is if the universe was created from dimensionless singularity, is singularity truly dimensionless? Can extreme gravity truly destroy all that is (space, time, matter, energy, just about...

Homework Statement Find and determine the type of singularity points for ##f(z)=\frac{\sin(3z)-3z}{z^5}##. Also calculate the regular and main part of Laurent series around those points.Homework Equations The Attempt at a Solution I am already having troubles with the first part. Singularity...

I was given the problem to: express the following signal in terms of the singularity function g(t)= t-1, 1<t<2 1, 2<t<4 4-t, 4<t<5 0, otherwise I graphed this function it is attached in below. My final answer for this function is g(t)=...

hello everyone like the prevailing theory now on how our universe origin has taken is THE BIG BANG. BUT i am studying in 11th and one of my lecturer told me that our universe when exploded from the big bang singularity it's size was 10^-36 m any idea on that? like how scientists...

Hey, so I've been wondering about this question for a while and was wondering if anyone could support the Big Bang theory in this respect or anything else. Just wondering if anyone has an answer that might aid me in understanding this, thanks.

Hi everyone. Suppose we consider an electron in a two dimensional lattice, whose dispersion relation is given by: $$ \epsilon(k_x,k_y)=-J(\cos(k_x a)+\cos(k_y a)), $$ and where the wave vectors belong to the first Brillouin zone (k_i\in [-\pi/a,\pi/a]). In this case it turns out that the...

I have a couple of questions I cannot find a good answer to in the internet, so I ask you guys. I have heard about singularity as a infinite small point with infinite gravity - I talk about what I assume is the center of black holes. The scientist are talking about quantum gravity - the...

I've read that there's a point in a black hole where matter is infinitely dense. There is zero volume but infinite density. How is it possible for something to have zero volume but have an infinite density at the same time?

Does a FRW universe with the equation of state: $$p = -\frac{\rho c^2}{3}$$ have a singularity at the Big Bang? I was looking at: http://en.wikipedia.org/wiki/Penrose%E2%80%93Hawking_singularity_theorems and trying to decide if such a Universe obeys the "dominant energy condition"...

Gravity is zero at the center of the earth. how come the same set of equations predict the gravity to be infinity at the center of a black hole? where does the singularity really come into picture? how is a black holes center different from Earth's center?

Is there evidence of space surrounding the BB singularity?

in a text a read that " \oint \nabla A \cdot dl = 2 \pi n wich implies that the gradient of A has a pole singularity" why there is a singularity? I thing that this is a contidion to integral is nonzero but ¿what is the theorem used?

Singularity Spin Mechanics Okay I within the last week too a look at a article about black hole spin and in this article it was said by a scientist that black hole's spin near the speed of light that are supermassive blazars I was thinking if a object is spinning wouldn't that make this...