Holes Definition and 1000 Threads

Is there agreement here or are all/most of the neutrons in the same state?

While watching the Discover Channel, they mentioned a jet of gas emitting from a black hole . . . . yet they say they are so powerful that not even light can escape them. So if not even light can escape the gravity, how would "jets of gas"? As a side note, . . . I realize that most of...

Sorry if someone already asked these, but I didn't see anything that was the same. A few of my friends are in a film class and we're working on a little indie movie, and the concept of it is a micro black hole is discovered at the edges of our solar system, and we want to make it somewhat...

I have a question that's been bothering me for a couple of days, and none of my professors have been able to answer it. Two observers, Alice and Bob, are initially at rest relative to each other. Bob begins a constant acceleration. I want to be specific; let's say his acceleration is g and...

If I take a plane with n holes, would the fundamental group be that of the "bouquet of n circles"? (http://en.wikipedia.org/wiki/Rose_(topology ).) The bouquet of circles is the same as the unit line with n-1 points identified. All three spaces initially appear quite different so it would be...

Gravitons are considered to be the mediating particles of gravitational force just as photons are considered to be the mediating particles of electromagnetic force. Both have zero rest mass. If extreme gravity of black holes does not allow photons of light to escape, why does it not do the same...

So... my first post, and bear in mind, all I know of Black Holes is what I've read of Black Hole and Penrose Effect articles on Wikipedia. (don't hate me) Would it be possible to use Black holes' Ergosphere for FTL travel? And this is all on the "if" that we, or some other race, achieved...

If Dark Matter is made of particles, then wouldn't it be possible to have clumps of it collapse into a black hole? Would there be any radiation from that collapse that we could see? Would that radiation be distinct from the formation of normal black holes? Shouldn't we be able to measure the...

I am believing that event horizons refer to where light can no longer escape the gravity of a black hole. What about everything else that moves at less than the speed of light? If a small moon winked into existence at some point further out than the event horizon with momentum that was sending...

Unlike other people, I find black holes puzzling. Let's consider some black holes of modest size, say a few solar masses: Suppose we have a smallish black hole rotating significantly (read: spinning like its angular momentum represents a large fraction of the energy equivalent of its rest mass...

How are black holes linked to worm holes, or are they the same thing, for example can you use any of them to transport through space, and if you can, would it go to a different location of the universe your in, or can it go to another universe as in another dimension?

I was checking the news this morning when I happened upon this shocking story: http://ste5ens.files.wordpress.com/2009/04/april-fool-illus.jpg

Some black holes may actually be "Quark Stars" http://www.usatoday.com/tech/science/space/2009-12-07-quarkstar07_ST_N.htm?utm_source=feedburner&utm_medium=feed&utm_campaign=Feed%3A+UsatodaycomScienceAndSpace-TopStories+%28Tech+-+Science+and+Space+-+Top+Stories%29": excerpts below: So how...

I have an issue I'm not quite sure how to approach. A customer is requesting that we prove that our battery pack chassis will not burst or deform if additional gases are introduced inside the enclosed box (the batteries could vent). The chassis is assumed to be a sealed .05" thick 5052 AL...

If black holes usually form when stars collapse, how do white holes form?

In GR, the strength of gravity goes to infinity at singularities. But what if in nature, gravity increases up to a certain cut-off, and does not continue to increase. If the cut-off is sufficiently low, could it be gravity is not strong enough to overcome pauli exclusion principle, and...

What are black holes? A theory I have is simple, and thus must be wrong. It seems to me that black holes are just extremely dense balls of matter, not holes at all, really. Just superdense balls. So, what is the real explanation, likely involving 105 vectors and 31 dimensions?

Hi All, So I'm a current physics grad student - who's supposed to give an outreach presentation (over skype) to some 5th graders who have been learning about Black Holes. I have no problem with the technical content - but does anybody have some good ways to explain things to elementary...

Hello everyone, I have a question that bothers me quite some time now,and it would be great to get an answer. I have been reading some time now about black holes,and photons,and how black holes attract photons and different theories says it can or cannot escape the black hole,and there`s...

Do we know the magnitude of gravitational force needed to violate the Pauli exclusion principle? Also, I my research has told me that violating the principle still isn't enough to turn the fallen star into a black hole. It could still become a neutrons star, so if that is the case, what...

What does quantum physics have to say about black holes?

according to special relativity the mass of an object increases with its velocity by the lorentz factor. the lorentz faktor would be 2.3 for when traveling at 90% the speed of light. as you go faster and faster the lorentz factor increases. it would be 22.4 when traveling at 99.9% the speed of...

So I'm watching this video: http://www.youtube.com/watch?v=TSOPq9rZYcU&NR=1 So it says that nothing, even light, can escape a black hole, "except for certain Quantum Mechanic situations" or something like that. What are these Quantum Mechanic situations they are talking about? Try to...

What will happen if two black holes are coming nearby? what will be the reaction (change in behavior)?

Homework Statement give a simple argument which will explain why holes in semiconductors are generally heavier and less mobile than electrons. Homework Equations The Attempt at a Solution Is it something to do with the fact that the hole represents the movements of a lot of...

I propose to collect here some links which may be over the head of most PF users, but which should be invaluable for SA/Ms who feel the need to quickly brush up before addressing some thorny question involving the concept of certain topics related to gtr. In this post, Useful Background...

Is it possible for a star and a black hole to rotate each other in a relatively stable way without the BH feeding on the star and if yes could that star have planets rotating around it?

Do positively charged holes have any other quantum numbers assigned to them? What are the similarities and differences between a hole and a positron?

Hi there, (i) What does BPS black hole mean? Under what conditions can they form and where does it come from? (ii) What is the difference between an AdS black hole and a ordinary Schwarzschild? Thanks a lot!

Today I was conversing online in a gaming community and we began talking about relativity. Eventually we started talking about the "fabric of space and time" and how the common model to represent this idea was the old 'ball on a trampoline' idea; a 2-d model. To get straight to the point, we...

Hello... If time stops at the event horizon of a black hole..which means there is no motion happening or can be observed..does that not mean that the centre of a black hole is a place of absolute rest? Could such a place of ab/rest 'move' thru the cosmos (basically a black hole which is a...

This is my first posting to PF, so I do apologise if my post does not adhere to the etiquette of the forum. I had been considering black holes recently, and I had a thought/question which I am interested to hear people's feedback on, as I have not found a lot of information specifically on...

Right, it's been a long time since I've done anything physics related, and I've never been an expert to begin with, just a level standard, but was having a bit of a chat with a friend earlier and wanted to see if what we were saying makes any sense atall? We were having a bit of an...

Hi, I have to say that I'm not sufficiently educated in physics but I'm very interested in it so please excuse my silly questions. First I'd like to ask what determines the quantity of space that the black hole occupies. Is it just the amount of matter that imploded during the super nova...

Black Holes are Singularities... or vice versa? Ok so a Singularity is a place in space time where gravity or the things used to determine gravity become infinite. So does this mean that Black Holes are types of Singularities or Black Holes have Singularities in the center, or Black Holes and...

lets say we had a black hole or something that created a large gravitational field , one that could accelerate something to near the speed of light , so we would have a certain amount of mass or energy that could accelerate our object to near the speed of light as close as we could get it , if...

Maybe a simple or stupid question so bear with me (it is late and I just thought of this). Assuming the existence of gravitons and assuming they are mass-less and travel the speed of light - how can they escape a black hole? Please point me in the right direction.

The majority view in the physics community is that black holes not only can exist, but do exist. I accepted this for a long time, but I recently came across a website that claims black holes cannot exist and provides references to a great many papers on the topic that don't seem at all to be...

Simple question to ask, but probably not so simple to explain an answer: Can an object moving faster than light (I would say a tachyon, but I don't want to since there are different theories about what a tachyon might be) escape from a black hole? Obviously a black hole isn't just about...

What actually are electron holes? I have come to read that electron holes are nothing but the blank space that is left behind when an electron is missing in a crystal where it ought to have been present. I have also learned that the movement of holes are due to adjacent electrons jumping into...

Hi all, Apologies if my understanding is a bit simplistic but even if my question turns out to be idiotic, I'm sure I'll learn from your replies. Thanks in advance! So the reason dark matter was postulated in the first place is because the observed gravitational effects in the known...

What I am posting here it is not an alternate theory nor a criticism of any accepted theory. I just have an idea born from what I know (like a non-specialist) about cosmology and I need your help to understand if it is a good idea or a wrong one. Related to expansion of Universe we can...

I would request for help in understanding why the drift speed of electrons in semiconductors is more than that of holes. Thanks.

When two black holes collide, do their singularities merge the instant their event horizons touch? Or is there a lag between the event horizons touching and the singularities merging when there are actually two singularities inside a single black hole?

Hello. I have been set a problem by a student. It appears to be fairly old, but I cannot find much info in the web. Here it is: A 1" cube has three holes drilled in it, each hole connecting the centres of opposite faces, thus forming a cavity in the centre joined to the surface by six holes...

Say our early Universe had a significant fraction of its mass in the form of a uniform dust of plank mass black holes, along with the visible matter of our present universe. How might you figure such a dust would evolve in our early universe to our present epoch? Would such a dust clump just...

2 black holes, 2*M --> 1 b.h., 2*M - f*2*M? For equal sized black holes of mass M, what fraction, f, of the energy typically gets lost as gravitational radiation when roughly equal sized black holes merge? If f were plotted verses mass would the function have a maximum? Thanks for any help!

Hi everyone. Does anyone know what would happen if two black holes got too close toghether? Would the merge and become a supermassive black hole?

One of the arguments for the existence of a minimum distance, the Planck distance, is (*) that in order to probe a smaller distance, you need a probe, e.g. a photon, of wavelength smaller than that distance, that is, of very high energy, and indeed such high energy that when it is localized it...

Hello all, I'm currently doing a research paper on the coalescence of two Supermassive black holes (Sagittarius A and the Supermassive black hole at the center of the Andromeda galaxy) and have come across some difficult quandaries. First since (to an outside observer) nothing ever comes...