Dark matter comes out of the cold

[rogers_buck]

http://news.bbc.co.uk/1/hi/sci/tech/4679220.stm <br /><br />So it is the WIMPS that rule the universe! <br />

 

[kmarinas86]

I wouldn't be surpised or disturbed if cosmology turned yet another way.<br /><br />We've hardly explored outside our own solar system yet (Voyager 1). Some think we can fathom it using imagination and first prinicples like we build towers of cards. But a real exploration of deep space could blow down such towers.<br /><br />Moons like Io and objects like Sedna surpise astronomers. Cosmologists will be more surpised, more than they are right now, given that a handful of "first principles" supported by the mainstream cosmology are errorenous. That is not out of the question, it is a fact that it is possible.

 

[bonzelite]

^^^ +10<br />

 

[silylene old]

I am still skeptical about accepting the dark matter hypothesis, even as I understand why this hypothesis was invoked to describe several observations. Perhaps it is true, as the hypothesis is consistent with observation. Or perhaps we cling to tightly to incomplete mathematical descriptions of gravity which apply best over shorter distance, and yet fails over huge distances due to additional (undescribed) terms which increase its very long-range attraction. Dark matter still seems strikes me to be a bit like like aether theories of the 19th century.<br /><br />I am still a skeptic on dark matter, and await more observations and description. (same goes for dark energy) <div class="Discussion_UserSignature"> <div class="Discussion_UserSignature" align="center"><em><font color="#0000ff">- - - - - - - - - - - - - - - - - - - - - -</font></em> </div><div class="Discussion_UserSignature" align="center"><font color="#0000ff"><em>I really, really, really miss the "first unread post" function.</em></font> </div> </div>

 

[kmarinas86]

A homogeneous universe proposed by the big bang implies that diversity does not increase with distance. The reality of heterogeneity from scales of the subatomic to the galaxial implies that diversity is compounded as distance increases, with diversity existing on these scales. It is not hard to imagine that the farther we see, the more different the universe will look, and indeed that is what we observe.<br /><br />Because of observations, three categories can be defined:<br /><br />1. A universe that is homogeneous throughout space and heterogeneous throughout time. (Evolving homogenous universe, e.g. big bang)<br /><br />2. A universe that is heterogeneous throughout space and homogeneous throughout time. (Animated fractal universe whose generic appearance is the same for all times, e.g. universe is a self-similar fractal)<br /><br />3. A universe that is heterogeneous throughout space and heterogeneous throughout time. (A chaotic universe where the laws change - an unpredictable universe submissible to mysticisms and such - where time travel is possible - where "anime" physics becomes a possibility, and so on) <br /><br />What we know from observation is that you can't have both space and time be homogeneous.

 

[bonzelite]

#3<br /><br />

 

[rogers_buck]

Our ability to imagine outstrips our ability to observe. Our ability to observe outstrips our ability to explain. When our imaginations do the explaining we will have arrived at a perfect theory - many, many, perhaps never years from now.

 

[bonzelite]

good words.

 

[mikeemmert]

I get a density of 1.13 micrograms/cubic kilometer. Anybody want to check that figure?

 

[bonzelite]

the article overall is vague and explains nothing. <br /><br />it mentions the flat radial velocity of galaxy rotation as a vague oversimplification: <br /><font color="yellow"> "its presence, though, can be inferred from the way galaxies rotate: their stars move so fast they would fly apart if they were not being held together by the gravitational attraction of some unseen material."</font><br /><br />that does not explain jack shanola. or the idea that if "dark matter" were there, it would have to **perfectly graduate in mass**, from lesser to greater, from center to the edge of the galaxy ---impossible! <br /><br />yet they will <i>never consider that something other than gravity is acting upon the galaxy, or that they do not fully understand the nature of gravity --they will never admit to this in a million years. they would rather re-engineer a fruitcake that nobody likes to eat but must tolerate at christmas than admit that they don't know their a from a hole in the ground.</i><br />------------------<br />and more vagueness here:<br /><br /><font color="orange">"The distribution of dark matter bears no relationship to anything you will have read in the literature up to now," explained Professor Gilmore. If this 'temperature' for the dark matter is correct, then it has huge implications for direct searches for these mysterious particles <br /> <br />Prof Bob Nichol<br />Institute of Cosmology and Gravitation, Portsmouth<br /><br />"It comes in a 'magic volume' which happens to correspond to an amount which is 30 million times the mass of the Sun.<br /><br />"It looks like you cannot ever pack it smaller than about 300 parsecs - 1,000 light-years; this stuff will not let you. That tells you a speed actually - about 9km/s - at which the dark matter particles are moving because they are moving too fast to be compressed into a smaller scale.<br /><br />"These are the first properties other than existence that we've been able determine."</font><br /><br />huh? fi

 

[rogers_buck]

At 10,000 degrees, you'll need to adjust out the mass equivalence...<br />