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Dark Matter Thoughts

Posted: Fri Feb 26, 2010 8:33 pm
by The Code
I Awoke this morning with Dark Matter On Mind. With I hope a very interesting thought.

http://asterisk.apod.com/vie ... 31&t=18499

Black Holes, Dark Matter, Dark energy, All Dark? Or Unseen?

This is to inspire other thoughts, And invoke discussion. My thoughts this morning at 4am where About the possible relationship between Dark Matter, Dark Energy, and Black Holes. What happens, when matter passes into a black hole?
To us, A hadron, Is a small particle, But to a black hole, does it go even further? Can a hadron be split into a billion smaller particles. And then on and on, to the extent Matter is there but can not be detected by instruments. Matter becomes so small, it does not give of energy or reflect light. Yet it still exists, and still has a gravity signature. But then it struck me. Dark matter, Unknown process inside a black hole, Jets, A Galaxy, A 20th of what we see, to its gravity weight. Dark Matter must be as old as the galaxy. And increasing in size. But here,s where it gets interesting. The Matter we see on a daily basics must have these, DM And DE locked together in normal atoms/particles. Why? Because the early universe said so. The pressure and heat of the so called BB Fused the smallest of particles, to make bigger ones, and this went on and on and on until you get the hydrogen filled early universe. and even then it did not stop. Heavier and heavier particles as you all know. But when matter falls into a black hole. The process is reversed, Atoms/particles are stripped back down to the unknown matter. And released in the jets. Dark Matter And Dark Energy.

Any Ideas on this?

Re: Dark Matter Thoughts

Posted: Fri Feb 26, 2010 9:24 pm
by Chris Peterson
mark swain wrote:I Awoke this morning with Dark Matter On Mind. With I hope a very interesting thought...
Do you have a specific question? Otherwise, I think this belongs on the Cafe forum. This one is more for asking questions and getting answers; The Cafe is for looser discussions.

Re: Dark Matter Thoughts

Posted: Sat Feb 27, 2010 9:25 am
by harry
G'day from the land of ozzzz

Mark you note is a bit rough and yet has a logic that many scientists are searching.

Keep reading up on this topic.

I would post links, but you can search Axions 2010 on arXiv

and also the formation of jets from condensed matter.

Re: Dark Matter Thoughts

Posted: Sat Feb 27, 2010 10:46 am
by harry
G'day Mark

I thought you may find this link quite interesting. This axion particle was first noted some 30 odd years ago within the standard model of particle physics. These thoughts are mainstream.

Dark Matter Axions
00/2010

NASA ADS
http://adsabs.harvard.edu/abs/2010IJMPA..25..554S

arXiv
http://adsabs.harvard.edu/cgi-bin/nph-d ... db_key=PHY
The hypothesis of an 'invisible' axion was made by Misha Shifman and others, approximately thirty years ago. It has turned out to be an unusually fruitful idea, crossing boundaries between particle physics, astrophysics and cosmology. An axion with mass of order 10-5 eV (with large uncertainties) is one of the leading candidates for the dark matter of the universe. It was found recently that dark matter axions thermalize and form a Bose-Einstein condensate (BEC). Because they form a BEC, axions differ from ordinary cold dark matter (CDM) in the non-linear regime of structure formation and upon entering the horizon. Axion BEC provides a mechanism for the production of net overall rotation in dark matter halos, and for the alignment of cosmic microwave anisotropy multipoles. Because there is evidence for these phenomena, unexplained with ordinary CDM, an argument can be made that the dark matter is axions.

Re: Dark Matter Thoughts

Posted: Thu Apr 15, 2010 7:11 pm
by livemind
Dark Matter, if it exists, is incredibly dense matter on the subatomic scale,each speck spaced miles apart. Dark Matter has mass or it would not bend light .. it must be an incredibly dense particle if such a large percentage of it fills the universe yet allows light to flow through the universe .. each particle must be seperated by huge distances or light would be stopped (mass stops or deflects or absorbs light .. there is no passing through of light through mass). Mostly though, Dark Matter has just as much chance of not existing as it does existing. It is a flip of the coin. There are other explanations well established and worked out including different gravity theories. So there.

Re: Dark Matter Thoughts

Posted: Fri Apr 16, 2010 9:41 am
by harry
G'day

Bystander posted two links from wiki on dark matter and dark energy.

It basically defines the terms although still we are in limbo in understanding the terms.

Dark/Enery matter is nuclear matter in various phase forms and this could be from extreme light to ultra dense matter found in the centres of stars and galaxies. The nuclear matter can have a neutral charge, positive or negative charge or spins.

The quantum dynamics of this ultra dense matter holds the secrets to the formation and evolution of the parts within the universe.

Re: Dark Matter Thoughts

Posted: Fri Apr 16, 2010 10:30 am
by makc
harry wrote:Dark/Enery matter is nuclear matter in various phase forms and this could be from extreme light to ultra dense matter found in the centres of stars and galaxies. The nuclear matter can have a neutral charge, positive or negative charge or spins.
Why don't you edit those wiki pages to include this statement? See how it goes there. If it gets reverted, promise not to post it here also, ok?

Re: Dark Matter Thoughts

Posted: Sat Apr 17, 2010 8:07 am
by harry
G'day MakC

Refering to wiki

http://en.wikipedia.org/wiki/Dark_Matter
Composition
Unsolved problems in physics What is dark matter? How is it generated? Is it related to supersymmetry?

Although dark matter was inferred by gravitational lensing in August 2006,[27] many aspects of dark matter remain speculative. The DAMA/NaI experiment and its successor DAMA/LIBRA have claimed to directly detect dark matter passing through the Earth, though most scientists remain skeptical since negative results of other experiments are (almost) incompatible with the DAMA results if dark matter consists of neutralinos.


Estimated distribution of dark matter and dark energy in the universeThe dark matter component would have much more mass than the "visible" component of the universe.[40] Only about 4.6% of the mass of Universe is ordinary matter. About 23% is thought to be composed of dark matter. The remaining 72% is thought to consist of dark energy, an even stranger component, distributed diffusely in space.[41]

Some hard-to-detect baryonic matter is believed to make a contribution to dark matter but would constitute only a small portion.[42][43]

Determining the nature of this missing mass is one of the most important problems in modern cosmology and particle physics. It has been noted that the names "dark matter" and "dark energy" serve mainly as expressions of human ignorance, much like the marking of early maps with "terra incognita."[41]

At present, the most common view is that dark matter is primarily non-baryonic, made of one or more elementary particles other than the usual electrons, protons, neutrons, and known neutrinos. The most commonly proposed particles are axions, sterile neutrinos, and WIMPs (Weakly Interacting Massive Particles, including neutralinos).

None of these are part of the standard model of particle physics, but they can arise in extensions to the standard model. Many supersymmetric models naturally give rise to stable dark matter candidates in the form of the Lightest Supersymmetric Particle (LSP). Heavy, sterile neutrinos exist in extensions to the standard model that explain the small neutrino mass through the seesaw mechanism.

Data from a number of lines of evidence, including galaxy rotation curves, gravitational lensing, structure formation, and the fraction of baryons in clusters and the cluster abundance combined with independent evidence for the baryon density, indicate that 85-90% of the mass in the universe does not interact with the electromagnetic force. This "nonbaryonic dark matter" is evident through its gravitational effect.

Historically, three categories of nonbaryonic dark matter have been postulated[44]:

Hot dark matter – nonbaryonic particles that move ultrarelativistically[45]
Warm dark matter – nonbaryonic particles that move relativistically
Cold dark matter – nonbaryonic particles that move non-relativistically[46]
Davis et al. wrote in 1985:

Candidate particles can be grouped into three categories on the basis of their effect on the fluctuation spectrum (Bond et al. 1983). If the dark matter is composed of abundant light particles which remain relativistic until shortly before recombination, then it may be termed "hot". The best candidate for hot dark matter is a neutrino ... A second possibility is for the dark matter particles to interact more weakly than neutrinos, to be less abundant, and to have a mass of order 1eV. Such particles are termed "warm dark matter", because they have lower thermal velocities than massive neutrinos ... there are at present few candidate particles which fit this description. Gravitinos and photinos have been suggested (Pagels and Primack 1982; Bond, Szalay and Turner 1982) ... Any particles which became nonrelativistic very early, and so were able to diffuse a negligible distance, are termed "cold" dark matter (CDM). There are many candidates for CDM including supersymmetric particles.[47]

Hot dark matter consists of particles that travel with relativistic velocities. One kind of hot dark matter is known, the neutrino. Neutrinos have a very small mass, do not interact via either the electromagnetic or the strong nuclear force and are therefore very difficult to detect. This is what makes them appealing as dark matter. However, bounds on neutrinos indicate that ordinary neutrinos make only a small contribution to the density of dark matter.

Hot dark matter cannot explain how individual galaxies formed from the Big Bang. The microwave background radiation as measured by the COBE and WMAP spacecraft, while incredibly smooth, indicates that matter has clumped on very small scales. Fast moving particles, however, cannot clump together on such small scales and, in fact, suppress the clumping of other matter. Hot dark matter, while it certainly exists in our universe in the form of neutrinos, is therefore only part of the story.

The Concordance Model requires that, to explain structure in the universe, it is necessary to invoke cold (non-relativistic) dark matter. Large masses, like galaxy-sized black holes can be ruled out on the basis of gravitational lensing data. However, tiny black holes are a possibility.[48] Other possibilities involving normal baryonic matter include brown dwarfs or perhaps small, dense chunks of heavy elements; such objects are known as massive compact halo objects, or "MACHOs". However, studies of big bang nucleosynthesis have convinced most scientists that baryonic matter such as MACHOs cannot be more than a small fraction of the total dark matter.
What makes up nuclear matter is one of the LHC experiments.

Re: Dark Matter Thoughts

Posted: Sat Apr 17, 2010 2:20 pm
by Chris Peterson
harry wrote:What makes up nuclear matter is one of the LHC experiments.
Your point? There's is nothing in the discussion of dark matter about "nuclear matter". You are using a term that has no single definition, and which you haven't defined for us. What is "nuclear matter"? The term is usually used to describe a phase state, and one that is likely to have no physical meaning at all, or to describe matter only in extreme environments, like the core of neutron stars. Again, nothing to do with dark matter, which most likely is made of of non-baryonic particles.

Re: Dark Matter Thoughts

Posted: Sat Apr 17, 2010 3:02 pm
by bystander
What's the (dark) matter? We may not know for 10 years!
Scientific American Observations - 17 Apr 2010
Maybe science really is back in vogue. Or maybe "dark matter" is a case of remarkably successful scientific branding—who wouldn't be drawn in by a name like that? Then again, maybe people just want to know what the heck makes up the vast majority of the universe, a question to which science has provided only sketchy answers.

Whatever the reason, a dark matter lecture by physicist Peter Fisher at the American Museum of Natural History in New York City drew a sellout crowd April 12 in a theater that seats more than 400, with museum staff turning away disappointed comers and at least one gentleman trying to talk his way in as if he were working to get past the velvet rope at a nightclub.

Re: Dark Matter Thoughts

Posted: Sat Apr 17, 2010 10:26 pm
by harry
G'day

Thank you for the link bystander.

http://www.scientificamerican.com/blog/ ... 2010-04-17

In comes back to what makes up an atom, how does it form. Does subatomic particles (dark matter/energy) have a memory to reform atoms.

Signals could be from dark matter
http://news.bbc.co.uk/2/hi/science/nature/7977102.stm

The instrument that recorded this signal was measuring the ratio of positrons - the anti-particles of electrons that have a positive rather than a negative charge - to electrons.

It found a relatively high ratio of positrons within a "high energy level".

"The ratio [of positrons to electrons] should decrease with increasing energy," said Piergiorgio Picozza, a professor at the University of Rome Tor Vergata, Italy, and one of the authors of the research.

"But we found that, at one particular energy range, it increases, and that's not what we expected."
Spinning stars

"Since we know a lot about the background sources of positrons and electrons, we know what fraction we would expect to see at this particular energy level," explained Nigel Smith, who carries out research into dark matter at the UK's Rutherford Appleton Laboratory but was not involved in this research.

THE PAMELA MISSION

Pamela stands for: Payload for Antimatter Matter Exploration and Light-nuclei Astrophysics
The satellite carries instruments to identify particles and anti-particles
It is expected to orbit the Earth for a minimum of three years
"It's like light; when you see different colours, you're looking at photons - light particles - with different energies."

However, there could be another explanation for the positrons. They may come from pulsars - rapidly rotating, super-dense, dead stars that release lots of energy into the cosmos.

Nasa's Fermi Gamma-ray Space Telescope, which was launched in June 2008, is already taking measurements from pulsars and should produce data that could clarify the mysterious signal.

Professor Smith thinks pulsars provide the most likely explanation.

"It's the simplest solution," he said. "I think everyone will be waiting for the Fermi data to come in."

Professor Picozza agrees that pulsars offer a plausible, if less exciting, origin.

"Many leading theoreticians think this signal must come from dark matter," he continued.

"But I don't think this data alone is enough to claim that discovery. What we have found is another primary source of positrons."

He believes that the particles thought to constitute dark matter could be reproduced in the Large Hadron Collider (LHC) in Switzerland.

Re: Dark Matter Thoughts

Posted: Sat Apr 17, 2010 11:12 pm
by bystander
harry wrote:Signals could be from dark matter
http://news.bbc.co.uk/2/hi/science/nature/7977102.stm
UCI: Link between excess positrons and dark matter doubted
http://asterisk.apod.com/vie ... 31&t=19094

Re: Dark Matter Thoughts

Posted: Sun Apr 18, 2010 8:00 pm
by alter-ego
Chris Peterson wrote:
harry wrote:What makes up nuclear matter is one of the LHC experiments.
Your point? There's is nothing in the discussion of dark matter about "nuclear matter". You are using a term that has no single definition, and which you haven't defined for us. What is "nuclear matter"? The term is usually used to describe a phase state, and one that is likely to have no physical meaning at all, or to describe matter only in extreme environments, like the core of neutron stars. Again, nothing to do with dark matter, which most likely is made of of non-baryonic particles.
In defense of harry, I have a comment. The use of "nuclear matter" has also confused me for reasons that Chris has mentioned, but at generic level of discussion, I think I might know what harry's point is. Basically he's supporting the LHC's (high-energy particle physics) importance in solving the DM mystery. Barring details of how DM might show itself or how it is even identified (!), a byproduct of hadron collisions can be / is non-baryonic matter. One of the simplest, collision-free example, is the free neutron (beta) decay to a proton + electron + antineutrino. The latter two byproducts are non-baryonic (do not interact with the strong force). Therefore, I think it is correct to say hadrons can play a critical role generating DM candidates. So in a broad-brush description, DM secrets could be uncovered by subjecting "nuclear matter", i.e. hadrons, to extreme energy conditions (LHC and "centers of stars").

In my mind, this is the level to which harry's comments apply to main-stream thinking. Personally, I'm more excited about being close to DM breakthroughs than about what I think DM is. And just to be clear, I'm keeping Dark Energy out of the discussion. Until there is bona fide corroborating observational evidence, trying to link DE and DM together is going too far.

Re: Dark Matter Thoughts

Posted: Sun Apr 18, 2010 9:50 pm
by hstarbuck
I have been reading Origins by Neil DeGrasse Tyson and Donald Goldsmith and like the simplicity of this:
All matter has mass>>all mass has gravity>>Does all gravity have mass?
Until further notice it's all speculation (albeit educated speculation). Neutrinos oscillate, therefore vary over time, therefore do not move at the speed of light, therefore have mass (most people will agree to this at this point, right? A Nobel prize was given out for this.) However, as far as I know neutrinos are never even close to being static--they zing around all over all the time in many directions (Earthly or heavenly sources). I believe dark matter/dark gravity is more static--or at least located in the same places over time--not randomly distributed. My current thoughts are that if something "like" neutrinos is a candidate for DM it must be very different--able to glob up or attach to regular matter--yet never interact with light. It might not be mass at all! Physics would be boring if we knew all the answers.

Re: Dark Matter Thoughts

Posted: Mon Apr 19, 2010 1:18 am
by alter-ego
hstarbuck,

It's funny, for some reason every time I see you post, I think of coffee...

Anyway, you've asked several questions, and details abound. All great questions!
First of all, everything has a wavelength whose value depends on energy. Quantum Mechanics dictates that only at Absolute Zero Temperature (a state of zero energy) does a particle NOT oscillate.
1. Does gravity have mass? Of course I don't know for sure. Mass and gravity go hand in hand, but ultimately, General Relativity defines gravity as curvature of space, any Energy (rest mass or otherwise) contained within that space affects curvature. Do the theoretical particles Higgs boson and Gravitons have mass? I can only guess.
2. Neutrinos supposedly are very light particles that travel near the speed of light. The fact they oscillate is not the reason they travel fast. They travel fast because they are byproducts of high energy reactions, and the conservation of energy requires they travel VERY fast. You're right, if particles have non-zero (but real) mass, the most accurate theory to date (GR) says they must travel < c.
3. DM randomly distributed (ultra)relativistic particles or not? Of the little I've read, the thoughts appear to support slow-moving particles to help explain the observed clumpiness. If that's the claim, I have questions myself. For a region in space, where for a snapshot in time it takes hundreds of million of years for light to traverse, and more than enough time for life-cycles of high-energy cosmoslogical events to occur, I can see relativistic particles producing clumpiness. This concept only works for transient, non-steady state phenomena occurring over vast regions of space. This is all speculation on my part. If there are random high-energy phenomena that generate random high-energy byproducts in random locations and directions in space (galaxy collisions, star formation and death, black-hole creation, etc) at random times, then I would expect to not only see inhomogeneity in the distribution of the byproduct energy distributions, but also a changing distribution of this energy distribution over a long enough observation time. To me this is thought provoking. Maybe DM is NOT slow-moving particles (relative to human time scale). I've not seriously considered any consistency to existing theories for this "hot" high velocity particle discussion. Very likely the whole thing falls apart and only "static" heavy particles work for DM. I'm just thinking out loud here. If neutrinos are the DM particles (I believe current theory predicts there is not enough neutrinos to account for all DM believed to exist), then my thoughts are they don't have to coagulate or clump, exept due to self-gravity from the self-induced space curvature. There are other reasons why DM may appear to clump.

Take my last item with a grain of salt. As I said earlier, I'm looking forward to what the next breakthroughs are, not what I believe today. For today, having enough self-confidence to share possibly outlandish ideas in a public forum is my personal breakthrough.

Re: Dark Matter Thoughts

Posted: Mon Apr 19, 2010 9:12 am
by hstarbuck
alter-ego,
Thank you for entertaining my post. I have a few comments/clarifications myself which I will insert into the quote.
alter-ego wrote: First of all, everything has a wavelength whose value depends on energy. Quantum Mechanics dictates that only at Absolute Zero Temperature (a state of zero energy) does a particle NOT oscillate.
By oscillate I was referring to changing "flavors" of neutrinos (like from tau to muon). An electron (yes, and everything else no matter how massive) has a de Broglie wavelength but does not change to positron. But, I think this is now slightly off the track of dark matter.
1. Does gravity have mass? Of course I don't know for sure. Mass and gravity go hand in hand, but ultimately, General Relativity defines gravity as curvature of space.
I was actually not asking if gravity had mass, but if all gravity was tied to mass. According to Newton's law or Einstein's theory (I am told) the quick answer is yes. Can we actually prove that all gravity is tied to matter? or at least matter from this visible universe? By observing gravitational effects we infer dark matter/mass but there could be a totally different connection. Kind of funny to think that black holes are like familiar objects (from the outside) compared to dark matter at the present.
2. Neutrinos supposedly are very light particles that travel near the speed of light. The fact they oscillate is not the reason they travel fast. They travel fast because they are byproducts of high energy reactions, and the conservation of energy requires they travel VERY fast. You're right, if particles have non-zero (but real) mass, the most accurate theory to date (GR) says they must travel < c.
Neutrinos are cool.
3. DM randomly distributed (ultra)relativistic particles or not? Of the little I've read, the thoughts appear to support slow-moving particles to help explain the observed clumpiness. If that's the claim, I have questions myself. For a region in space, where for a snapshot in time it takes hundreds of million of years for light to traverse, and more than enough time for life-cycles of high-energy cosmoslogical events to occur, I can see relativistic particles producing clumpiness. This concept only works for transient, non-steady state phenomena occurring over vast regions of space. This is all speculation on my part. If there are random high-energy phenomena that generate random high-energy byproducts in random locations and directions in space (galaxy collisions, star formation and death, black-hole creation, etc) at random times, then I would expect to not only see inhomogeneity in the distribution of the byproduct energy distributions, but also a changing distribution of this energy distribution over a long enough observation time. To me this is thought provoking. Maybe DM is NOT slow-moving particles (relative to human time scale). I've not seriously considered any consistency to existing theories for this "hot" high velocity particle discussion. Very likely the whole thing falls apart and only "static" heavy particles work for DM. I'm just thinking out loud here. If neutrinos are the DM particles (I believe current theory predicts there is not enough neutrinos to account for all DM believed to exist), then my thoughts are they don't have to coagulate or clump, exept due to self-gravity from the self-induced space curvature. There are other reasons why DM may appear to clump.

Take my last item with a grain of salt. As I said earlier, I'm looking forward to what the next breakthroughs are, not what I believe today. For today, having enough self-confidence to share possibly outlandish ideas in a public forum is my personal breakthrough.
I will be waiting with you and everyone else.

As for the coffee connection there is no relation and I have to pay full price like everyone else.

Re: Dark Matter Thoughts

Posted: Mon Apr 19, 2010 2:18 pm
by bystander
alter-ego wrote:In defense of harry, I have a comment ... at generic level of discussion, I think I might know what harry's point is.

I think you give harry too much credit. In view of harry's history, I'm not sure harry had a point and even if he did I'm not at all sure that even he could tell you what it was. He could, however, provide you a long, unrelated reading list. :wink:
this is the level to which harry's comments apply to main-stream thinking.
harrry's comments almost never apply to main-stream or even to the topic at hand. He seems to live in a different world. Maybe it comes from being upside down all the time. :wink:
  • Pay no attention to that man behind the curtain.

Re: Dark Matter Thoughts

Posted: Tue Apr 20, 2010 4:25 am
by alter-ego
Hello hstarbuck,
Thank you for the clarification on neutrino oscillation. I was in left field and a decade behind! I still thought there was a still solar deficit of neutrino production, so you helped me learn something new.
hstarbuck wrote:I was actually not asking if gravity had mass, but if all gravity was tied to mass. According to Newton's law or Einstein's theory (I am told) the quick answer is yes. Can we actually prove that all gravity is tied to matter? or at least matter from this visible universe? By observing gravitational effects we infer dark matter/mass but there could be a totally different connection. Kind of funny to think that black holes are like familiar objects (from the outside) compared to dark matter at the present.
Proving that gravity is tied to matter? Another good fundamental question. As I understand it, there is no direct, independent proof for this. This is one of those self-consistent cases where GR describes the relationship precisely, and observation backs up the theory so accurately every time there is a new test, that the ONLY conslusion is that the mass / gravity relationship is true! So far, Einstein's theory is right, always right to the precision of measurement and analysis at the time. Here we are 100 years later, still conducting veryification tests only to find Einstein space-time descriptions and predictions still pan out. I mean, we are striving to see gravity waves, and I'm sure there is a strong feeling that they WILL be there. Now, I expect someday that experiments will reveal consistent descrepancies, and maybe an extended GR will be needed to fill the hole. And back to your question, there may be a day where a new, more complete theory will evolve which will "prove" in line-item fashon that there has to be a constraint on the speed of light, e.g. equals a constant in all reference frames. I mention this because that one concept exists ONLY as a postulate in a theory that has proven so powerful, and is the fundamental foundation to GR. To my knowledge, there is no "proof" that this must be so. So this one postulate that c = constant, has led to GR and all that it explains and predicts, and from this, the almost certain truth that mass gravity are connected through space-time. But I have to admit, that when there is a new test, part of me hopes something new and unexplained is revealed. When nothing new is revealed, I just am amazed. Right now, GR seems to confirm Dark Matters existence, as well as the right range of quantity too I believe. But GR can't tell us what DM is.

You are right, it seems we are pretty accepting of the now familiar black holes. I'm waiting for a new player: Dark Black Holes :wink: .

Re: Dark Matter Thoughts

Posted: Tue Apr 20, 2010 4:58 am
by bystander
alter-ego wrote:I'm waiting for a new player: Dark Black Holes.
Did 'Dark Stars' Spawn Supermassive Black Holes?
http://asterisk.apod.com/vie ... 31&t=18335

Why Black Holes May Constitute All Dark Matter
http://asterisk.apod.com/vie ... 31&t=18818

Dark Matter May Give Neutron Stars Black Hearts
http://asterisk.apod.com/vie ... 31&t=19141

Re: Dark Matter Thoughts

Posted: Tue Apr 20, 2010 12:19 pm
by harry
G'day Bystander

Thank you for your kind comments.

If you only read 1% of the papers that I go through maybe you may get some idea.

I try to inform by posting links and maybe get out of the fantasy world.

Science is not a club.

Re: Dark Matter Thoughts

Posted: Fri Apr 30, 2010 12:31 pm
by makc
this seems to be last post by harry. his profile says he was visiting us today, but did not post anything for 10 days now. no wonder that neufer surpassed him in 1000 posts club.
Image

Re: Dark Matter Thoughts

Posted: Mon May 31, 2010 5:01 am
by astrolabe
Hello hstarbuck,
hstarbuck wrote:All matter has mass>>all mass has gravity>>Does all gravity have mass?
The short answer is no. There are, of course, definitions for Gravity that on the surface seem plausible enough in telling us what it is but, truth be told, all that gets described are the effects of gravity, where it might be found and what properties have been observed. Gravity only describes the phenom- not the thing itself. So, if we don't honestly KNOW what Gravity is we are left with an observation of an effect seemingly caused by a force(?) that needed a name. Isaac called the force(?) Gravity but he, like us don't know what it is. It's no wonder we struggle with DM. We know it's nature and that's all- just like Gravity.

If, however, particles lose energy via radiation (heat loss) and therefore become colder matter is formed. High energy particles seek low energy states or at least equilibrium and these lower energy states or balanced partnerships (atoms?) fall into larger collected states and become for the most part visible. Einstein stated that space was merely an extension of matter which makes a ton of sense to me. A Black Hole especially the larger ones can actually be colder than the CMBR by a Kelvin or two, nearly absolute zero, whereas the surrounding matter such as a Galaxy is relatively warm. matter that falls into a BH only does so when it's energy level drops low enough to allow it. I feel that the jets that result are made up of the high energy given off as the matter breaks down which spirals around the BH and gets ejected at the poles.

I have learned that a lot about our Universe in not intuitive but it is logical and since I'm not any thoughts, corrections or insights are always welcome and- in the interest of learning- appreciated

Re: Dark Matter Thoughts

Posted: Mon May 31, 2010 9:46 am
by makc
astrolabe wrote:So, if we don't honestly KNOW what Gravity is we are left with an observation of an effect seemingly caused by a force(?) that needed a name. Isaac called the force(?) Gravity but he, like us don't know what it is. It's no wonder we struggle with DM. We know it's nature and that's all- just like Gravity.
Is there anything then that we do know what it is? As it has been pointed out many times in this forum, elementary particles are also just a theory that fits observations. Also see recent double slit experiment thread.

Re: Dark Matter Thoughts

Posted: Mon May 31, 2010 10:41 am
by harry
G'day

Did someone call?

I have being around in one form or another.

Keep Cool

Busy reading

Re: Dark Matter Thoughts

Posted: Mon May 31, 2010 3:40 pm
by astrolabe
Hello makc,

I guess the LHC has based it's entire reason for being on the info built up over the eons that particles do indeed exist, to which I totally agree and who wouldn't. But, alas, Gravity is an entirely different matter (no pun intended of course) to which some scientist believe that the graviton does not exist. So I don't know where to go from there except towards what we do know which is energy levels and densities. For all else, like you say, are just names for observations. Peace.