Black holes Definition and 1000 Threads

2 closely orbiting massive objects are predicted to deserve the fabric of spacetime so much that they will release a ripple of gravitational waves. When geavitational waves are released, they slowly loose velocity energy and spiral into one another. 2 pulsars were discovered orbiting each other...

are black holes just dead stars with lots of mass which shrunk to small size and got lots of gravity, or an actual hole in space-time? if they're actually holes, where do they lead stuff that gets in them? if they're just dead stars with lots of gravity, their mass must grow over time because of...

the time for crossing the event horizon is infinite,so no singularity,no evaporation and no loss of information could be observed?

I wish to take up a discussion between Elroch and DrStupid in RossiUK’s topic “First Post – a question about Black Holes and Gravity”. My post is essentially an exposition of Elroch’s view, which I have shared for many years. Elroch’s exposition was very sedate, and I feel it needs to be shouted...

If light is transmitted by photons and photons are massless and gravity only affects particles with mass, then why can't light escape black holes' giant gravitational force?

how long do black holes last before they vaporize?

I was on Youtube the other day and found a series of videos that explain the four fundamental forces in terms of a basic particle called the kaon. I basically understood the first 13 videos, but at video 14 I was lost. In the first few videos, they explain gravity, basically stating that it is...

Hi there, First post, so be gentle. I'm currently doing a project on Kerr black holes, part of which is based on a project in Edwin F. Taylor's book "Exploring Black Holes" (the chapter is found here) as well as some of Hartle's book (chapter 15). Part of my project, and as a way of better...

If nothing can escape black holes, how are relativistic jets of particles and radiation emitted from the supermassive variety of the same? Are they emitted from the BH proper or from something else? IH

Are they really black? And are they really holes? I'd say they are actually neither. Would I be right?

If a black hole is a center of unbelievable gravitational force why is it always illustrated as a hurricane? These depictions remind me of a drain in one's bath where the water swirls in from the sides and drops in through the top of the drain. Wouldn't objects be drawn in centrally from all...

I'm a fan. Not a physicist or astronomer.. But this question is bothering me. If the mass of an object increases to infinity as it approaches the speed of light, does that also create infinite gravity at the object? And if so, if we consider the gas swirling around the black hole is very...

In a brief history of time it says theft 'according to the uncertainty principle rotating black holes should emit particles'. However I do not understand why rotating black holes need to emit particles according to the uncertainty principle. I do understand why black holes emit particles it...

[Correct me if I'm wrong about anything ;) ] We once though that the rate of expansion over that universe was slowing down. However, we now see that it's actually speeding up and the present theory is that matter will eventually move so fast that current laws of attraction will devolve and...

First time poster, more of a nerd than an academic. So virtual particles, can they pop into and out of existence inside the event horizon of a black hole? What about in the black hole itself? If nothing can escape and matter is torn apart, what happens to those quantum particles? Or maybe...

In General Relativity gravity is described as being a consequence of spacetime geometry. In Quantum Mechanics the different forces are described as being mediated by quanta. One of the predictions of QM is the existence of a particle that mediates gravity, namely the graviton. What I do not...

Now, I must preface this by saying that my understanding of QFT is limited, and my understanding of GR is even more so. Nevertheless, I was reading about the No Hair Theorem, and it seemed to me to be suggestive of the indiscernibility of Quantum Particles. Obviously, for a macroscopic black...

Assuming that black holes do in fact evaporate via Hawking Radiation, how can an infalling observer ever get inside the event horizon if the black hole evaporates in a finite time from an outside observers frame?

Can black holes be disintegrated by a sufficiently powerful explosion? If an explosion from various types of astrophysical phenomena occurs near a black hole, can the explosion disintegrate the black hole if the force of the explosion is greater than the gravitational force of the black hole?

Sorry, new here, and my actual mathematical training is v.limited, so I have to restrict myself mostly to thought experiments, alas. Anyway... Whenever I study up on black holes, it doesn't take very long before the text or discussion quickly devolves into how impossibly abberant...

Ok so I am in an argument with my mother about the nature of black holes. She is religious and has classical physics knowledge up to degree level (she has a master's in mechanical engineering) and is very, very stubborn. Ok so she has a theory that physicists have simply arrogantly overlooked...

I'm curious - once an object passes the event horizon the image of that object remains on the event horizon only to become more redshifted rather than dissipating. two questions: 1) why does the image remain if the light stops traveling? if the light cannot travel to the observer, than there...

Hi, I've been thinking about the concept of charged black holes. What I'm wondering is this; if light cannot escape a black hole, and photons are the bosons of the EM force, then is it meaningful to describe a black hole as having a 'charge'? If the photons can't escape the black hole, then no...

Good evening. I have been reading that the repulsion generated by the Pauli exclusion principle barely prevents neutrons in neutron stars from occupying the same quantum states (after all, they are fermions). However, the principle seems to be violated in a black hole, given that fermions are...

Hi, I'm doing some research on sound. I'm interested in finding out what happens to a sound wave just BEFORE it reaches a black hole and what happens when it ACTUALLY reaches a black hole ? Can someone direct me to the right place for this ? Thanks for the help

Black holes only emit hawking radiation which is black body radiation. If black holes only emit photons then the black hole can never get rid of charge which means it can never get rid of all its mass. Does this means black holes also emit charged particles?

I want to clarify some stuff about black holes and have some questions: 1) From the perspective of a hovering near the event horizon observer an external universe evolve at very fast rate. But from the perspective of a free falling observer an external universe slows down. Correct? 2) If...

Do Planck units apply inside of black holes? Are they modified? Or are they irrelevant? If some Planck units remain unchanged and applicable in black holes, which ones would those be?

I understand that a gravity well bends space-time such that, close to it, time passes "slower" than further away. The archtypical example is that if a chronometer were dropped into a black hole, we would observe it to tick slower and slower as it approached the event horizon. Based on this, I...

So imagine your on Earth at a latitude of 30 to 45° N, between two rotating Kerr Metric Blackholes with detached event horizons (dual singularities) allowing you to be shielded from the crushing force of the black holes. Which way do the rotating black holes need to rotate for the past and...

So from what I understand, virtual particles that are created at the edge of a black hole can become the small detectable radiation (hawking radiation) if one of the particles falls into a black hole, becoming a real particle (its partner now no longer has to annihilate with it) and the second...

I'm a huge noob and I don't know much about physics and space and stuff, but I was thinking about this in the shower today.. Anyone care to comment? Or correct me on anything? Ok, so I was talking about to Daniel about Gravity, the Sun, and Black Holes.. (Yes we are ghetto nerdy xD) And i...

In another topic, a member dave13214321323 or whatever his name is :p said that the popular opinion is that in the early universe gas contracted into denser spaces forming galaxies and black holes were consequences of galaxy formation, not the other way around; Black holes at centers of galaxies...

I often see, when people talk about black holes, someone claim that since there are no huge tidal effects at the supermassive black hole's event horizon, that someone on a spaceship falling into such a black hole would not be destroyed and would survive, continuing inwards, until, after some...

Does how black holes inside galaxies orbit around the central black hole tell us anything useful? Could be my noobness, but the idea of a bunch of black holes orbiting a central black hole just seems messy. ha. Have we got the jist of what would happen if a black hole ate another black hole? if...

I'm asking because some of you state that flat spacetime can't model black holes... meaning even between the Planck scale and event horizon, but yet atyy said spin-2 field in flat spacetime is equivalent to General Relativity for spacetime that is covered by harmonic coordinates which atyy...

Do black holes become larger and larger with all the matter and light they consume? And is it possible for a black hole too merge with other black holes?

Is it possible that a particle traveling so close to c from its reference frame observes objects within their schwarzschild radius? In other words is it possible that in these particles reference frames is a universe primarily comprised of black holes? If so then would gravity be relative?

Is there any theory for which "elementary" particles are "small" black holes or/and for which the electron and the proton would be a pair of associated black holes? Does such question even be meaningful ? Or is it just science-fiction, the fruit of any crazzy imagination?

I'm a newbie, and I've got some questions that are raised by Leonard Susskind's "The Black Hole War," a fascinating non-technical book about his argument with Stephen Hawking about whether or not information is conserved even if it is dropped into a black hole. I've read several threads and the...

Hi all, While the articles I have been reading are about a year old (which can be considered relatively outdated in terms of particle physics) I have been looking at the possibility of Neutrinos being able to travel at FTL (Experiments conducted by CERN and OPERA). I understand in the articles...

I understand that there may be no answer to the question "Why is Pauli Exclusion Principle not applied beyond a Neutron Star's mass?" since there may not be a full quantum gravity theory yet, however, I'm thinking, what if Pauli Exclusion Principle is not really a principle, but an indication...

I need to know when did the first black holes appear?

Hey guys, I'm a new guy in this forum. I've been visiting it for 1 year actually but never decided to register and so I did. I am having a presentation on black holes at school and I want some clariffication of what's going on when falling into a black hole. Well let's assume that an...

1. Photons approaching a black hole will initially a. all of the above are possible depending on distance from the event horizon b. pass by with their direction changing (bending/curving) c. fall into the black hole d. go into orbit around the black hole e. pass by without...

Hello, Let me first start off by saying that I have no formal Education or background in Physics or Astronomy save for one course during college. This is simply posing an idea I had while reading an article on the acceleration of the expanding universe and how it could have a correlation with...

hi, i was wondering, for a black hole, as everyone knows,the escape velocity is greater than light. this means that the information about the existence of the black hole in terms of light never reaches the observer. so if the black hole were the cease to exist at an instant of time, the...

My question is this: Does the direction of spin of a supermassive black hole exert an affect on the spin of its surrounding galaxy (given that the above described black hole is at the center of such a galaxy)? Is there a direct or correlative effect? If so, can an in-depth explanation be...

Hey everyone, I have some questions about quantum physics and black holes. For starters, what happens to an entangled particle as it enters a super massive black hole? Would gravity just break the entangled state because of the extreme forces? The only issue i see with that is that...

Suppose two black holes graze one another in a high speed encounter. The collision is glancing such that the event horizons merge and then separate. Q1) I assume this is possible? Now suppose that the collision is nearly but not completely collinear. Q2) Is it true in this case that...