Black hole formation

[Jacques]

To have a blakhole we need enought mass in a small volume. A neutron star with more than 3 solar mass will do. The gravity is strong enought to overcome the repulsion of neutron

http://hyperphysics.phy-astr.gsu.edu/hbase/astro/blkhol.html

 

But something is bugging me. Relativity tells us that the more intense the gravity the slower time is going. From our point of view we would see the collapse of the neutron star going slower and slower until the Schwarzchild radius is attained. At this radius from our point of view time will almost be stopped: it will take an infinite amount of time for the collapse to finish.

 

If the universe have existed a finite time how can blackhole have formed?

[ed84c]

It is relative to the viewer on the outside.

 

Again you can say the same 'how can somthing ever have fallen into a hole', well to our eyes, it hasnt, it would fade slowly as the wavelengths became longer and longer, until we could no longer see it.

 

Imagine it in the sense that space time is falling into a hole at the speed of light.

 

Hope that sheds some light on the matter, so to speak.

[Jacques]

Ed84c

We are viewer on the outside and I understand that the radiation from an object falling in the hole will be more and more redshifted. Also we will see the object going slower and slower. Do you agree with that ?

Imagine it in the sense that space time is falling into a hole at the speed of light.

Can you elaborate a little more. I am trying to imagine but I need more informations to figure what you mean.

[ed84c]

hmm ill have a look for 'Black Holes a travellers guide', if i do ill scan in the pages about this and post them on OK?

[RawThinkTank]

Formation of an balck hole is any ways impossible.

 

Before formation of blackhole the density of matter near the surface of the star will blow up any star into supernova as the G is maximum at surface of any object.

[Sayonara]

Formation of an balck hole is any ways impossible.

 

Before formation of blackhole the density of matter near the surface of the star will blow up any star into supernova as the G is maximum at surface of any object.

What?

[RawThinkTank]

At least someone without ego problem used the word "WHAT?"

[Sayonara]

That doesn't really answer my question.

[Dave]

Formation of an balck hole is any ways impossible.

 

Before formation of blackhole the density of matter near the surface of the star will blow up any star into supernova as the G is maximum at surface of any object.

 

I think you may need to think a little more about this, because it doesn't really seem to make sense.

[RawThinkTank]

if what is the question then I must answer it with

 

"Please be more elaborative about it"

[Dave]

What could possibly make you think that black holes don't exist when we have evidence that they actually do?

 

(I'm presuming that's what you meant by your previous post, because it didn't make a whole lot of sense to me).

[Sayonara]

if what is the question then I must answer it with

 

"Please be more elaborative about it"

Very well:

 

"Please explain all of that again, using sentences and physics, including a demonstration of why our observations of black holes are not, in fact, observations of black holes."

[RawThinkTank]

Very well:

 

"Please explain all of that again' date=' using sentences and physics, including a demonstration of why our observations of black holes are not, in fact, observations of black holes."[/quote']

 

There are no such observations of which I am aware of.

[[Tycho?]]

Formation of an balck hole is any ways impossible.

 

Before formation of blackhole the density of matter near the surface of the star will blow up any star into supernova as the G is maximum at surface of any object.

 

The part that makes sense is wrong, not sure about the part that doesn't make sense.

[Sayonara]

There are no such observations of which I am aware of.

I'm sure there are a lot of things that have been observed you aren't aware of; that doesn't mean none of them were observed.

[Ophiolite]

There are no such observations of which I am aware of.

Are there any grammars of whose you am awares of?

[Jacques]

Sayonara

There is no direct observation of black hole. By definition a black hole can not be observe. Black hole were predicted by theory and when astronomer found some hight energy phenomena that were not explainable otherwise, they assigned that to the effect of a blackhole. THe center of galaxy where the stars goes to fast, the X-ray comming from these region are all attributed to the effect of a black hole.

These effect could also be attributed to a very very dense object, but an object that doesn't go to the limit of the blackhole predicted by theory. My questionning is that from the general relativity principle how can a black hole ever form.

[us.2u]

And not to forget our opposites doe's any one know of white holes?

[Sayonara]

There is no direct observation of black hole. By definition a black hole can not be observe. Black hole were predicted by theory and when astronomer found some hight energy phenomena that were not explainable otherwise' date=' they assigned that to the effect of a blackhole. THe center of galaxy where the stars goes to fast, the X-ray comming from these region are all attributed to the effect of a black hole.

These effect could also be attributed to a very very dense object, but an object that doesn't go to the limit of the blackhole predicted by theory. My questionning is that from the general relativity principle how can a black hole ever form.[/quote']

I don't know enough about relativity to answer your question - I am simply refuting RawThinkTank's post.

 

Regarding observation: if something has all the attributes of a duck, and no extra attributes, we call it a duck - because we consider a duck to be something that has those attributes. It doesn't matter if the duck is powered by toffees, or came from the planet Blizzle.

If it has extra attributes that we can observe, such as a propellor or eighty-three heads, it's probably not a duck, because we don't call things with those attributes 'ducks'.

 

 

Look RTS! Mysterious reports of real scientists, doing real science!

 

http://news.bbc.co.uk/1/hi/england/leicestershire/3787671.stm

http://news.bbc.co.uk/1/hi/sci/tech/3626535.stm

http://news.bbc.co.uk/1/hi/sci/tech/3501313.stm

http://news.bbc.co.uk/1/hi/sci/tech/3303855.stm

http://news.bbc.co.uk/1/hi/sci/tech/2888081.stm

http://news.bbc.co.uk/1/hi/sci/tech/2868149.stm

 

Now stop evading the question and explain post #5.

[Sayonara]

And not to forget our opposites doe's any one know of white holes?

Yes, we call them "stars".

[timo]

That´t not correct Sayonara. The Schwarzschild solution which is usually used for spherical symmetrical mass distributions is only valid outside the distribution or, if the total mass distributions end up behind the evnet horizont, outside the event horizont. The Schwarzschild coordinates have a coordinate singularity at the event horizont. You can however find coordinate systems (Kuskal coordinates) that do not have a singularity at the event horizont. They are nessecary to show that a particle falling in a black hole actually does reach the singularity and does not stop at the event horizont as is would appear in a Schwarzschild coordinate system. Due to the lack of a coordinate singularity one could see the Kruskal coordinates as the better coordinate system for describing the spacetime of a spherical symmetrical mass distribution.

 

In Kruskal coordinates you suddenly map areas of spacetime you didn´t even see in Schwarzschild coordinates. You get two causally not connected areas of free space (parallel universes) and two regions inside an event horizont. One of those regions inside an event horizont has the strage behavior that all particles inside it must leave the area. So it´s quite the contradiction of the common behavior of a black hole where all particles inside must end up in the singularity. Because of this this area is called a White Hole.

I found a picture of this on the bottom of this page:

http://scholar.uwinnipeg.ca/courses/38/4500.6-001/Cosmology/Black_Holes.htm

The area called "time reversal black hole" is the white hole, The areas called "outside black hole" and "inside black hole" are the areas covered by the Schwarzschild coordinates. The unnamed area is the parallel universe. The geodesic equations for light is given by eq (2.18) as u+-v = const. A few of the light cones where the time-like geodesics must lie in are also shown.

 

As for us-2u´s question: No, afaik there is no observations of or hint towards the existence of a White Hole.

[Sayonara]

What's not correct? That we call white holes stars? If so, I'm aware of that - I was being oblique.

[ed84c]

Oblique?

 

I looked it up on dictionary.com and got collateral, i didnt know what that meant, so i looked up that and got concomitant I looked up that and got One that occurs or exists concurrently with another. but i dont think thats right

[us.2u]

Well done ed84c that was good effort; through this week I'll try to unravel these enigmas unless anyone else can enlighten us how about Ophiolite if anyone can it's you let's not hope we're in the dark for too long.....

[Sayonara]

I looked it up on dictionary.com and got collateral, i didnt know what that meant, so i looked up that and got concomitant I looked up that and got One that occurs or exists concurrently with another. but i dont think thats right

lol

 

Get a dictionary that's made out of paper.