Singularity Definition and 422 Threads

Homework Statement Determine the electric field and the charge density associated with the potential ##\displaystyle{V(r)=A\frac{\exp{-\lambda r}}{r}}##, where ##A## and ##\lambda## are constants. Homework Equations The Attempt at a Solution The electric field is easy to determine...

What happens to the Singularity when a Black Evaporates out of existence?

Hello, i am not sure where to discuss it but here maybe proper for this thread. I just want to discuss about DC's Tv show Flash and physics on it like singularity or parallel universes?

If a star with enough mass to become a black hole is rotating before it becomes a black hole, then the singularity of the black hole will actually be a ring singularity. How is it possible?

I seem to have missed the opportunity to post my questions on a related thread so I hope this is okay. First, a request. I have read on this forum that ["Singularity" is just shorthand for "the place where the math model breaks down and we don't know WHAT is/was happening".]. Since the wiki...

The singularity before the big bang, was it anything like the singularities in the universe today? Did it have a black hole around it, with an event horizon? And what caused the singularity to expand? Why did it expand when the singularities in our universe don't do anything besides suck stuff in?

I am trying to solve the poisson equation with neumann BC's in a 2D cartesian geometry as part of a Navier-Stokes solver routine and was hoping for some help. I am using a fast Fourier transform in the x direction and a finite difference scheme in the y. This means the poisson equation becomes...

I always has the impression that the density of the universe is infinite at the singularity because its just amount of stuff divided by volume and if the distance between stuff is 0 then the volume is 0. So divide by zero and you get infinity. But I have been told by others that dividing by zero...

In the big bang model the singularity is all ways quoted as being the start of the universe, but AFAIK scientists do not accept the singularity as real, the same with the black hole singularity, what is proposed to be in their place? from Wiki. The initial singularity was the gravitational...

Homework Statement http://me.erciyes.edu.tr/mkapalak/MKA-COURSES/STRENGTH-2/EXAMS/STR2-39-2.pdf How can (w/24)( <x-0.5L>^4 )= 0 ? by doing so, the author assume x <0.5L ? so that <x-0.5L> = 0 How do we know that? Homework EquationsThe Attempt at a Solution

A new paper on arXiv today claims that relationsism allows one to evolve the universe through the big bang. Alas I am not familiar with relationsism, is it related to shape dynamics? can anyone explain? https://arxiv.org/pdf/1607.02460v1.pdf

A significant number of physicists today postulate that the universe we reside in is infinite in size. It's also thought that if we extrapolate back in time to the big bang that the universe was a singularity of infinite density. Singularities are commonly thought of as a dimensionless point...

Hello Friends... I just need a help... I want to kno what happens to the Singularity inside the black hole when it evaporates... Help me out[emoji5] [emoji5] [emoji5]

As I understand it, the crux of the issue is: how is information preserved across the event horizon, in this case, the arrangements of subatomic particles, atoms, etc right on up through the individual parts, etc., of the creature in question. That, and the relativistic escape velocity required...

What has a higher density? Black Holes or Singularities? I looked online and all I saw was that they both have infinite densities.

I know this thread, about why the Universe can't expand inward, is fairly old; but I stumbled across it today and there was something mentioned here that sparked a question I feel like people here would be qualified to answer. What was mentioned, was that a singularity is a point at which our...

It seems I remember hearing (either on tv or mag) that there was a theory that the original singularity which resulted in the big bang could have been created from essentially nothing by ripples or something in the space energy...or something like that. Can anyone point me toward any articles...

Can someone point me to the seminal (or any other) paper explicitly showing and proving the formation of singularities in black holes? I'd like to learn about the exact physical processes which occur during the collapse of a star into a black hole and how the progress of those physical...

A good year ago, quantum corrections have been proposed to the very early Universe. It was concluded that these quantum corrections contain a precise estimation for the cosmological constant and the so-called radiation term. The authors even have interpreted the latter as evading the big-bang...

I need the symbol that discribes a singularity for a novel I am writing. Can anyone help? Many thanks Mark

In the schwarzschild metric, inside the event horizon the r coordinate becomes timelike, and when when r=0 the coefficient of dr^2 is also 0. So time stops at the singularity, yet somehow it can move around and emit gravitons, i.e. "evolve" even when it's supposed to be frozen like a video...

https://en.wikipedia.org/wiki/Gravitational_singularity The two most important types of spacetime singularities are curvature singularities and conical singularities.[4] Singularities can also be divided according to whether or not they are covered by an event horizon (naked singularities are...

Please have pity for the idiot in the room. I've tried to look into this concept through a few papers I've found on-line, but the mathematics involved is too far over my head. I'm trying to wrap my head around the general concept of entropy as it applies to a singularity. In a singularity of...

A singularity is a region in which the curvature of space-time becomes infinite. But according to standard big bang models, at the initial point (at which T = 0) the pre-expansion space - as miniscule as it was - was filled uniformly with all energy that ever existed or will exist. But if all...

I've read Hawking's introduction: http://arxiv.org/abs/hep-th/9409195v1, which are nice. I would like something that explains the other singularity theorems and how they are related to Big Bang. I've tried reading Hawking & Ellis but I can't understand most of the definitions.

Does anyone know of an example, preferably a simple one, that can be used to demonstrate that we can have a curvature singularity without a singularity in the Kretschmann scalar?

Hello, I have a question to the singularities of spacetime (where the metric tensor is infinite, but not the coordinate singularities which can be removed be a change of coordinate) It's easy to show that a singularity of the riemanian tensor scalar RαβμνRαβμν leads to a singularity of the...

At any instant in time, for an atomic particle, are its characteristics singular?

Do black hole singularities have 0 volume? What forces are keeping the particles from being in the same place?

So, according to physicsoftheuniverse.com, "In the centre of a black hole is a gravitational singularity, a one-dimensional point which contains infinite mass in an infinitely small space, where gravity become (sic) infinite and space-time curves infinitely, and where the laws of physics as we...

It seems to me that the Schwarzschild singularity is generated by the metric function which is an invariant and so has the same value in any coordinate system, so why is it not equally valid?

Homework Statement Find and classify the singular point for f(z) = 1/ ( sin z - sin a) Where a is an arbitrary real constant. Homework Equations f(z) = 1/ ( sin z - sin a) Where a is an arbitrary real constant. The Attempt at a Solution There will be infinite number of singularities of sin z...

In general, what methods are there for proving that something is a non-curvature singularity? As a specific example, take the 1+1-dimensional version of the NUT metric, ##ds^2=t^{-1}dt^2-t d\theta^2##, which is discussed in Hawking and Ellis in two places. H&E's treatment is long and...

I thought of posting this on astrophysics or general relativity forums since it seems completely classical, but given the extraordinary claim, I am posting here. Note that one of the guys is a notable string theorist. http://arxiv.org/abs/1510.03396v1 Journey Beyond the Schwarzschild Black...

Hi, I am trying to design a lifting platform for light duty loads (3d printing build platform) that only uses rotation for its actuation. I have a design that uses a mechanism similar to the slider crank and I want to maximize the total height the platform can travel. This is a sketch of my...

Well, it's physics friday! (carpe diem etc, what else) :) 1. Homework Statement I present to you this (not so) pleasant expression that seemingly appeared on a page out of nowhere. \vec{F}(r, \theta, \varphi) = \frac{F_0}{ar \sin\theta}[(a^2 + ar \sin\theta \cos\varphi)(\sin\theta \hat{r} +...

Would it always be identical? Would it ever be identical? Essentially with the current state of physics and taking quantum fluctuations into consideration, would it always be the same? Is there motion at T=0?Another question: If we restarted the Universe from the big bang and let it play out...

When an neutrino is observed, it becomes a point particle, but it has mass. Is that mass not concentrated into a point? Why doesn't it collapse down to a micro black hole? What's the difference between a neutrino and a micro black hole of the same mass? I know it has 1/2 spin and other...

What is a nonscalar curvature singularity, in the context of "the https://en.wikipedia.org/w/index.php?title=Wave_of_death&action=edit&redlink=1 is a gravitational plane wave exhibiting a strong nonscalar null...

Hello people, I have a question regarding black holes. The way i understand it, black holes form in supernovas, and they occur because the gravitational pull of the stellar remnant is so great that nothing can stop it, and it basically collapses down to a singe point, virtually nothing... Now...

what is the nature of singularity of the function f(x)=exp(-1/z) where z is a complex number? now i arrive at two different results by progressing in two different ways. 1) if we expand the series f(z)=1-1/z+1/2!(z^2)-... then i can say that z=0 is an essential singularity. 2) now again if i...

I read this book called How To Teach Relativity to Your Dog by Chad Orzel. In the book he discusses how an electron is known to have mass but is also considered a point like particle. He said that some interpretations consider the electron thus to have an infinitely dense mass which should...

Following on from this thread. If the universe is infinite and was at the time of the big bang does that not mean that the size and contents was infinite? In other words at the BB there was already infinite amount of galaxies. I had understood that at, or just after, the BB the mass of the...

Predicted Heat Death of the Universe In his thought provoking documentary “Wonder of the universe” ( ) Professor Brian Cox explains the thinking behind current predictions for the “Heat death of the universe”. He explains the predictions through the effect of the second law of thermodynamics...

What is the size of the singularity? 1. Is it 0 cm? 2. Is it below Planck length? 3. Is "the size of singularity" the wrong question, such as asking "what is the length of 500 celcius"? What does that mean? From event horizon all the way, just before, the centre, is vacuum? And suddenly there...

Dear PF Forum, I have a question about the size of "singularity" This question has already been asked here, Question about Schwarzschild radius But what I want to know is this density thing that I'd like a confirmation. Actually it's 2.9511896078372906 KM according to his...

What is space-time singularity? How it formed...? Is singularity possible..?

First off, I want to say hello. I have been interested in gravity for most of my life, I've just taken forever to do anything about it. Better late than never. That's my story and I'm sticking to it. :) By no means do I consider myself a professional by any means, but I have been putting out an...

If the Big Bang created space time, what did the singularity of the Big Bang "rest" on?

What would happen if there was a supernova explosion near a black hole ? Would it just sit there and absorb all the energy incident on it ? Or would it simply vaporize into elementary particles ? And if it does vaporize, could the remnants give us a clue as to the quantum state of matter inside...