If it hasn't been discovered yet, how do you - or anyone else - know it's a fact?GOD wrote:No, literature of manner you're asking for does not exist, because this fact about dark matter hasn't been discovered yet. Like most things still to be discovered, literature currently available only exists in the form most would consider to be rantings of individuals who are out of their mind.Nereid wrote:I haven't heard of such an idea, nor read of any such in the literature; do you have a paper you can cite where we can read more?GOD wrote: Your guess about what dark matter being tiny is correct, however it's not tiny black holes. It's simply matter that's smaller and vibrating faster than we can currently detect.
Dark matter, dark energy
Re: Dark matter, dark energy
Not quite sure what you're asking, Superdoc ...Superdoc wrote:Nereid said
have telescopes observed and sent evidence images of a white dwarf eating up the remains of a star after it dies or is this another dark matter?The other kind of supernova (Type Ia) is where a white dwarf acquires enough mass (hydrogen), from its companion, to detonate; there is neither a neutron star nor a black hole left ... all that's left of the star is an expanding shell of (mostly) 'unburned' oxygen and the heavier products of the carbon and oxygen fusion that 'blew' the star up.
Direct images of stars are very few (goredsox asked about this recently elsewhere in The Asterisk, IIRC) - the Sun, Mira, Betelgeuse, and that's about it - so there are none of white dwarfs.
But perhaps you are referring to accretion disks around white dwarfs, or of binary stars with one filling its Roche lobe, or of the matter streaming from a red giant (in a close binary) onto its white dwarf companion? Perhaps something like this?
in the above post "link" it shows the white dwarf's disk is pulling some of hot gas from its nearby star that is still not run out of hydrogen and is on its own right? but what i meant to ask was, does this Type Ia supernova becomes itself a dwarf star cuz it didn have enough mass to transform into either neutron or black hole, Or after supernova explosion the left out material and gases r pulled by accretion disk of a white dwarf that is surrounding it? so i was wondering if This has been observed or not discovered yet.
I'm still not quite clear on what you're asking, but ...Superdoc wrote:in the above post "link" it shows the white dwarf's disk is pulling some of hot gas from its nearby star that is still not run out of hydrogen and is on its own right? but what i meant to ask was, does this Type Ia supernova becomes itself a dwarf star cuz it didn have enough mass to transform into either neutron or black hole, Or after supernova explosion the left out material and gases r pulled by accretion disk of a white dwarf that is surrounding it? so i was wondering if This has been observed or not discovered yet.
Type Ia supernovae are thought to occur in binary systems in which there is a white dwarf acquiring mass (hydrogen) from its companion. Mira is such a system, but I don't think it's known (yet) whether the white dwarf will, one day, explode as a supernova.
When a white dwarf goes supernova, as a Type Ia, it is completely destroyed ... all of its mass (other than that which was converted into energy) becomes hot gas (plasma), expanding away; after a while, this becomes a supernova remnant (SNR), like this one.
An interesting question, still being researched, is: What happens to the (giant) companion, which 'donated' all the hydrogen that caused the white dwarf to go supernova?
This is a quite different fate from a core collapse supernova, which does end up as either a neutron star or black hole.
I feel I still haven't answered your question, sorry; would you mind re-phrasing it?
-
- Asternaut
- Posts: 4
- Joined: Sat Oct 20, 2007 5:51 pm
No source
Sorry, I didn't read about the existence of small black holes. I thought of it while out on a walk.
Re: No source
At one level, lots and lots of small black holes could account for the observed properties of dark matter.Larry Turner wrote:Sorry, I didn't read about the existence of small black holes. I thought of it while out on a walk.
However, at another level, it can't. Why? If the black holes originated after nucleosynthesis (when H, He, and a little Li were first formed), then they'd have to have come from these ('baryonic') components. However, if they did, then the consistency between the observed (primordial) abundance of the light nuclides and the CMB angular power spectrum would be lost (as well as several other consistencies). IOW, solve one puzzle, unsolve a dozen previously solved ones.
Of course, if the small black holes were formed before nucleosynthesis, then the inconsistencies would not arise ....
-
- G'day G'day G'day G'day
- Posts: 2881
- Joined: Fri Nov 18, 2005 8:04 am
- Location: Sydney Australia
Hello All
Our own Milky Way has millions of stellar black holes and a swarm of larger ones near the centre.
Than again what is a black hole?
We will never know.
Some think its a compact core of Neutrons that creates EM?g fields so trong that not even EMR can escape.
Why Neutrons and not protons (H+). The difference is an additional electron.
Neutrons have a neutral charge that enables them to be compacted to 10^17.
but! The repulsive forces stop the break down of Neutrons to Quarks. Thats one opinion.
The other is that extreme heat and EM/G fields break down the Neutrons to quark composites allowing a compaction from 10^17 to 10^25.
Our own Milky Way has millions of stellar black holes and a swarm of larger ones near the centre.
Than again what is a black hole?
We will never know.
Some think its a compact core of Neutrons that creates EM?g fields so trong that not even EMR can escape.
Why Neutrons and not protons (H+). The difference is an additional electron.
Neutrons have a neutral charge that enables them to be compacted to 10^17.
but! The repulsive forces stop the break down of Neutrons to Quarks. Thats one opinion.
The other is that extreme heat and EM/G fields break down the Neutrons to quark composites allowing a compaction from 10^17 to 10^25.
Harry : Smile and live another day.
harry, it seems you have a very confused understanding of the topic.harry wrote:Hello All
Our own Milky Way has millions of stellar black holes and a swarm of larger ones near the centre.
Than again what is a black hole?
We will never know.
Some think its a compact core of Neutrons that creates EM?g fields so trong that not even EMR can escape.
Why Neutrons and not protons (H+). The difference is an additional electron.
Neutrons have a neutral charge that enables them to be compacted to 10^17.
but! The repulsive forces stop the break down of Neutrons to Quarks. Thats one opinion.
The other is that extreme heat and EM/G fields break down the Neutrons to quark composites allowing a compaction from 10^17 to 10^25.
How did you decide "Our own Milky Way has [...] a swarm of larger [than stellar mass black holes] near the centre"?
Who thinks a stellar mass black hole is a "compact core of Neutrons that creates EM?g fields so trong that not even EMR can escape"?
What do the 10^17 and 10^25 refer to?
-
- G'day G'day G'day G'day
- Posts: 2881
- Joined: Fri Nov 18, 2005 8:04 am
- Location: Sydney Australia
Hello Neried
It is not I who is confused it is you.
I want you to do some research before I give you information on black holes in our milky way.
Making statements like:
I am surprised that you lack that information.
================================
Black Holes in my opinion are Neutron cores greater than 2.5 sun masses that prevent light from escaping. I have picked Neutrons for the simple reason they are able to be compacted to 10^17.
Some may argue that Neutrons are not the final compaction and maybe quark or preonparticles ranging 10^18 to 10^35. In theory it maybe so.
Neried as a moderator you must make your comments a little better.
It is not I who is confused it is you.
I want you to do some research before I give you information on black holes in our milky way.
Making statements like:
I have read thousands of papers. I'm not confused.harry, it seems you have a very confused understanding of the topic.
I am surprised that you lack that information.
================================
Black Holes in my opinion are Neutron cores greater than 2.5 sun masses that prevent light from escaping. I have picked Neutrons for the simple reason they are able to be compacted to 10^17.
Some may argue that Neutrons are not the final compaction and maybe quark or preonparticles ranging 10^18 to 10^35. In theory it maybe so.
Neried as a moderator you must make your comments a little better.
Harry : Smile and live another day.
Perhaps this one?makc wrote:Perhaps harry refers to that old APOD where we were asked to come up with funny name for black holes group found somewhere there?Nereid wrote:How did you decide "Our own Milky Way has [...] a swarm of larger [than stellar mass black holes] near the centre"?
If so, then the relevant paper would be "An Overabundance of Transient X-Ray Binaries within 1 Parsec of the Galactic Center":What do you call a group of black holes ... a flock, a brace, a swarm? Monitoring a region around the center of our Galaxy, astronomers have indeed found evidence for a surprisingly large number of variable x-ray sources - likely black holes or neutron stars in binary star systems - swarming around the Milky Way's own central supermassive black hole. Chandra Observatory combined x-ray image data from their monitoring program is shown above, with four variable sources circled and labeled A-D. While four sources may not make a swarm, these all lie within only three light-years of the central supermassive black hole known as Sgr A* (the bright source just above C). Their detection implies that a much larger concentration of black hole systems is present. Repeated gravitational interactions with other stars are thought to cause the black hole systems to spiral inward toward the Galactic Center region.
If so, then yet again harry seems to have misunderstood what he read!During 5 years of Chandra observations, we have identified seven X-ray transients located within 23 pc of Sgr A*. These sources each vary in luminosity by more than a factor of 10 and have peak X-ray luminosities greater than 5×1033 ergs s-1, which strongly suggests that they are accreting black holes or neutron stars. The peak luminosities of the transients are intermediate between those typically considered outburst and quiescence for X-ray binaries. Remarkably, four of these transients lie within only 1 pc of Sgr A*. This implies that, compared to the numbers of similar systems located between 1 and 23 pc, transients are overabundant by a factor of >~20 per unit stellar mass within 1 pc of Sgr A*. It is likely that the excess transient X-ray sources are low-mass X-ray binaries that were produced, as in the cores of globular clusters, by three-body interactions between binary star systems and either black holes or neutron stars that have been concentrated in the central parsec through dynamical friction. Alternatively, they could be high-mass X-ray binaries that formed among the young stars that are present in the central parsec.
Or, much worse, deliberately mis-stated.
I can't really decide, but given the vehemence of so many of his posts here, it's hard to avoid the latter conclusion.
Let's be charitable; let's interpret "Our own Milky Way has millions of stellar black holes and a swarm of larger ones near the centre." as merely sloppy, with 'larger ones' referring to the inferred 'swarm' of (possibly) low-mass X-ray binaries or (possibly) high-mass X-ray binaries. Let's also be charitable and overlook harry's omission of SgrA* (which would, in the same vein as his statement, read something like 'and a million-sol super-massive black hole at its gravitational centre').
But notice the vertiginous switch from (unscientific) dead certainty ("has millions of ...") to radical scepticism ("We will never know."). Notice the absence of a definition (in this case, black hole), with the implied 'consensus use' of the term, immediately followed by a (we now see) disingenuous mention of harry's own pet theory ("Some think ...").
See my previous post.harry wrote:Hello Neried
It is not I who is confused it is you.
I want you to do some research before I give you information on black holes in our milky way.
Making statements like:
I have read thousands of papers. I'm not confused.harry, it seems you have a very confused understanding of the topic.
I am surprised that you lack that information.
I look forward to your response.
What is this "10^17"?================================
Black Holes in my opinion are Neutron cores greater than 2.5 sun masses that prevent light from escaping. I have picked Neutrons for the simple reason they are able to be compacted to 10^17.
[snip]
May we conclude, from this statement of your pet theory, that you have strong evidence that neither General Relativity nor the Standard Model (of particle physics) are applicable to objects with masses of 2.5 sols and composed of neutrons?
Nereid ask:
"What is this "10^17"?
May be he dont know what a "unit" mean. Or he also cant read it since it's a "unit". Hmmm then he dont understand the question and that's why he is answering:
Quote:
"I want you to do some research before I give you information on black holes in our milky way."
Search google???? Gee, is that a top secret information?
So you mean, you dont know what Nereid ask you?
Babbling again!
Try to keep smiling!
"What is this "10^17"?
May be he dont know what a "unit" mean. Or he also cant read it since it's a "unit". Hmmm then he dont understand the question and that's why he is answering:
Quote:
"I want you to do some research before I give you information on black holes in our milky way."
Search google???? Gee, is that a top secret information?
So you mean, you dont know what Nereid ask you?
![Shocked :shock:](./images/smilies/icon_eek.gif)
Babbling again!
![Rolling Eyes :roll:](./images/smilies/icon_rolleyes.gif)
Try to keep smiling!
-
- G'day G'day G'day G'day
- Posts: 2881
- Joined: Fri Nov 18, 2005 8:04 am
- Location: Sydney Australia
Hello All
Hello Doum with an attitude like that,,,,,,,,,,,,,,,,get a life.
http://hypertextbook.com/facts/1998/AnthonyColgan.shtml
Kg/m3
I have given this before. I would have expected Neried and MakC to know.
As for Doum, he is too busy trying to be a smart cookie.
Neired I have given an opinion. If you have other information, please let us all know rather than trying to join a gang bang.
Information of Neutron stars and the so called black holes are all based on opinion.
Hello Doum with an attitude like that,,,,,,,,,,,,,,,,get a life.
http://hypertextbook.com/facts/1998/AnthonyColgan.shtml
Kg/m3
I have given this before. I would have expected Neried and MakC to know.
As for Doum, he is too busy trying to be a smart cookie.
Neired I have given an opinion. If you have other information, please let us all know rather than trying to join a gang bang.
Information of Neutron stars and the so called black holes are all based on opinion.
Harry : Smile and live another day.
Perhaps you would have so expected; does this mean that you expect only "Neried" and "MakC" to read your posts?harry wrote:Hello All
Hello Doum with an attitude like that,,,,,,,,,,,,,,,,get a life.
http://hypertextbook.com/facts/1998/AnthonyColgan.shtml
Kg/m3
I have given this before. I would have expected Neried and MakC to know.
What about the hundreds of others, both registered users and guests, who read them?
Elsewhere, harry, you stated that you love science, and that you've read thousands of papers. Let's take both statements at face value. You will have noticed, I'm sure, that units are always stated in scientific papers. And, as makc has pointed out, it is but a mere 5 keystrokes extra to add the units in this case.
May I suggest that if you wish readers to treat what you write with respect then you should respect them too?
Indeed, harry, you have given many of your opinions, including the one that you love science.As for Doum, he is too busy trying to be a smart cookie.
Neired I have given an opinion. If you have other information, please let us all know rather than trying to join a gang bang.
What was troubling me, in my first post commenting on what all readers now understand to be merely your opinions, is that you didn't indicate which were merely your opinions, which were your attempts to summarise what you'd read (in scientific papers and elsewhere), and so on.
My requests for clarification generated obfuscation (and more) but no clarification.
In this post of yours that I am quoting it seems clear that you have no intention of explaining your post; it seems you are, again, trying to shift the discussion elsewhere (a common tactic).
This, again, is curious (or not); if you love science, I'd've expected you to welcome the opportunity to provide sources, to explain, to clarify, and so on; after all, that's what scientists do, isn't it?
May one ask your opinion of SgrA*? In your opinion, what is its mass?Information of Neutron stars and the so called black holes are all based on opinion.
-
- G'day G'day G'day G'day
- Posts: 2881
- Joined: Fri Nov 18, 2005 8:04 am
- Location: Sydney Australia
Hello All
News Release - heic0116: First image and spectrum of a Dark Matter object
05-Dec-2001:
=======================================
News Release - heic0701: First 3D map of the Universe's Dark Matter scaffolding
http://www.spacetelescope.org/news/html/heic0701.html
News Release - heic0309: Hubble tracks down a galaxy cluster's dark matter
http://www.spacetelescope.org/news/html/heic0309.html
http://www.spacetelescope.org/news/html/heic0709.html
News Release - heic0709: Hubble finds ring of dark matter
15-May-2007:
News Release - heic0116: First image and spectrum of a Dark Matter object
05-Dec-2001:
This is close to the markFor the past ten years, active search projects have been underway for possible candidate objects for Dark Matter. One of many possibilities is that the Dark Matter consists of weakly interacting, massive sub- atomic sized particles known as WIMPs. Alternatively Dark Matter may consist of massive compact objects (MACHOs), such as dead or dying stars (neutron stars and cool dwarf stars), black holes of various sizes or planet-sized collections of rocks and ice.
=======================================
News Release - heic0701: First 3D map of the Universe's Dark Matter scaffolding
http://www.spacetelescope.org/news/html/heic0701.html
What standards and what reference?07-Jan-2007: By analysing the COSMOS survey – the largest ever survey undertaken with Hubble – an international team of scientists has assembled one of the most important results in cosmology: a three-dimensional map that offers a first look at the web-like large-scale distribution of dark matter in the Universe. This historic achievement accurately confirms standard theories of structure formation.
Fantastic info.The map provides the best evidence yet that normal matter, largely in the form of galaxies, accumulates along the densest concentrations of dark matter. The map reveals a loose network of filaments, intersecting in massive structures where clusters of galaxies are located.
This milestone takes astronomers from inference to direct observation of dark matter's influence in the Universe. Mapping dark matter's distribution in space and time is fundamental to understanding how galaxies grew and clustered over billions of years. Tracing the growth of clustering in the dark matter may also eventually shed light on dark energy, a force which repels matter rather than attracts it as gravity does, which may have influenced how dark matter clumps.
News Release - heic0309: Hubble tracks down a galaxy cluster's dark matter
http://www.spacetelescope.org/news/html/heic0309.html
Tracing dark matter is not an easy task because it does not shine. To make a map, astronomers must focus on much fainter, more distant galaxies behind the cluster. The shapes of these distant systems are distorted by the gravity of the foreground cluster. This distortion provides a measure of the cluster mass, a phenomenon known as "weak gravitational lensing".
http://www.spacetelescope.org/news/html/heic0709.html
News Release - heic0709: Hubble finds ring of dark matter
15-May-2007:
Astronomers have long suspected the existence of the invisible substance of dark matter as the source of additional gravity that holds together galaxy clusters. Otherwise, astronomers say, the clusters would fly apart if they relied only on the gravity from their visible stars. Although astronomers don't know what dark matter is made of, they hypothesize that it is a type of elementary particle that pervades the Universe.
Harry : Smile and live another day.
-
- G'day G'day G'day G'day
- Posts: 2881
- Joined: Fri Nov 18, 2005 8:04 am
- Location: Sydney Australia
Hello All
Cosmic degenerate matter: a possible solution to the
problem of missing mass
Cosmic degenerate matter: a possible solution to the
problem of missing mass
Abstract
Spontaneous symmetry breaking of a neutral scalar field coupled to gravity
leads directly to ultra-low mass bosons, with a critical temperature far above
the temperature of the Universe, for most of its duration. The particles are
therefore expected to condense into a degenerate Bose–Einstein gas, providing
a potential candidate for nonbaryonic nonluminous matter.
In conclusion, we have presented the simplest field model in which the prediction of
ultra-low mass bosons emerges naturally, given the currently accepted values of cosmological
parameters and fundamental constants. More elaborate models involving either greater
spacetime dimensions or additional particle interactions can be envisioned, and we are presently
considering some. These alternative models could very well lead to WIDGET masses different
by some orders of magnitude from the mass arrived at in this letter, but thatwould not affect our
principal conclusion—the possible existence of a Bose–Einstein condensate of cosmic extent—
since this phenomenon could occur throughout a very wide range of WIDGET masses. For
example, it follows from (22) that particles with masses as large as 10−6 eV—which are still
lower than any hypothesized for massive neutrinos—would form a Bose–Einstein condensate at critical temperatures below 1000 K, which is a temperature still far beyond any to be found
in the vacuum of interstellar space and the outskirts of galaxies.
Besides determining the cosmological constant, WIDGETs also add new interactions to
the gravitational field equations (13) through their contribution to the energy-momentum tensor
(14). An examination of specific modifications of the gravitational field equations engendered
by WIDGETs is beyond the scope of this present letter and will be discussed elsewhere.
When, after many years of experimentation, the first Bose–Einstein gas was finally
prepared in a terrestrial laboratory in 1995 [13], project co-director Eric Cornell remarked:
‘This state could never have existed naturally anywhere in the universe. So the sample in
our lab is the only chunk of this stuff in the universe, unless it is in a lab in some other solar
system’ [14]. It is interesting to contemplate that, if the conclusions presented in our letter
are confirmed, then the new state of matter, which even today can be created on Earth only in
relatively minute quantities under conditions of extraordinarily low temperatures, may well be
the most abundant form of matter in the cosmos.
Harry : Smile and live another day.
Dark matter or light matter
Maybe the answer is as simple as........
It´s light...
Not dark matter....
It´s the light and it´s forward projectory from every angle arround
multiple sun´s that makes it expand......
That´s why we cannot see it... because there´s nothing to bounce of from between matter. Once it hits matter then it becommes visible.
Take a look at al galaxy´s it is being brightend from every angle, but gravity keeps it from going faster..... Our sun makes very very very many stars light up, just like the rest of the sun´s we can see...
If we can sail solar wind, than it has power to move
And if you think about black holes, there just a multitude of solar winds
passing each other making a wirlpool of solar wind.... You never know.... We still have not proven this theory....
Be kind and remember this is only brainstorming form someone who´s
understanding is limmited by somewhat brainstorming sessions of this subject... no training of some sort..
Greetings from holland..
![Shocked :shock:](./images/smilies/icon_eek.gif)
It´s light...
![Idea :idea:](./images/smilies/icon_idea.gif)
Not dark matter....
![Exclamation :!:](./images/smilies/icon_exclaim.gif)
It´s the light and it´s forward projectory from every angle arround
multiple sun´s that makes it expand......
That´s why we cannot see it... because there´s nothing to bounce of from between matter. Once it hits matter then it becommes visible.
Take a look at al galaxy´s it is being brightend from every angle, but gravity keeps it from going faster..... Our sun makes very very very many stars light up, just like the rest of the sun´s we can see...
If we can sail solar wind, than it has power to move
![Wink :wink:](./images/smilies/icon_wink.gif)
And if you think about black holes, there just a multitude of solar winds
passing each other making a wirlpool of solar wind.... You never know.... We still have not proven this theory....
Be kind and remember this is only brainstorming form someone who´s
understanding is limmited by somewhat brainstorming sessions of this subject... no training of some sort..
Greetings from holland..
I think the reasoning as stated is this. Photonic pressure waves, interacting with each other, is what endy is theorizing as the cause of the expansion. We see barionic matter because it reflects photonic energy and we see this reflection, however we do not directly view photons. Is a photon the invisible "Dark Matter" and is Photonic energy the invisible "Dark Energy"?
Last edited by BMAONE23 on Tue Apr 22, 2008 4:55 pm, edited 1 time in total.