Posted on 01/02/2009 11:46:33 PM PST by LibWhacker
The first stars to light the early universe may have been powered by dark matter, according to a new study. Researchers from the University of Michagan, Ann Arbor call these very first stars "Dark Stars," and propose that dark matter heating provided the energy for these stars instead of fusion. The researchers propose that with a high concentration of dark matter in the early Universe, the theoretical particles called Weakly Interacting Massive Particles(WIMPs), collected inside the first stars and annihilated themselves to produce a heat source to power the stars. "We studied the behavior of WIMPs in the first stars," said Katherine Freese and her team in their paper, "and found that they can radically alter the stellar evolution. The annihilation products of the dark matter inside the star can be trapped and deposit enough energy to heat the star and prevent it from further collapse."
The philosophy behind this research is that 95% of the mass in galaxies and clusters of galaxies is in the form of an unknown type matter, dark matter. The researchers say, "The first stars to form in the universe are a natural place to look for significant amounts of dark matter annihilation, because they form at the right place and the right time. They form at high redshifts, when the universe was still substantially denser than it is today, and at the high density centers of dark matter haloes."
The concentration of dark matter at that time would have been extremely high meaning that any ordinary stars would naturally contain large amounts of dark matter.
Dark stars would have been driven by the annihilation of dark matter particles releasing heat but only in stars larger than 400 solar masses. That turns out to be quite feasible since stars containing smaller amounts of dark matter would naturally grow as they swept up dark matter from nearby space.
The stars continued, and may still continue to be powered by dark matter annihilation as long as there is dark matter for fuel. When the dark matter runs out, they simply collapse to form black holes.
If they exist, Dark Stars should be able to be detected with future telescopes, and if found, would enable the study of WIMPs, and therefore be able to prove the existence of dark matter.
OK, Although I think my theory is no good, lets go with galaxies are held in place by orbital dynamics. If orbital dynamics include the bending of space, this can cause the galaxies to collide. Einstein's theory says to stretch fabric out tightly, place a bowling ball in the middle, place a marble at the edge of the fabric, and the marble rolls toward the bowling ball because the fabric is pushing on it, not because of the gravitational pull of the bowling ball. The smaller galaxies would eventually collide with the larger galaxies for the same reason. The moon will collide with the earth, the earth with the sun. It would all work the same. This may be why the stars are not moving farther apart with the expansion of the universe. I don't know, I am just running with the ball. Most likely in the wrong direction.
We don’t disagree. I called “dark matter” a place holder for a more consistent theory. MOND is one candidate.
Nope. Every part of the universe is moving away from every other part as space-time itself expands. It's often described as raisins moving away from each other in a rising loaf of bread, the raisins representing galaxies and other such objects in space.
The hubble is not showing this to be true.
Oops! Didn't catch the part until later. :)
Oops! Didn't catch that part until later. :)
This is not good because the Milky Way would have to be the biggest galaxy.
Sure it is.
From your earlier post:
The Hubble is showing the universe expanding in all four directions from the the Milky Way. The funny thing is, the stars are not expanding further away from each other. If all of the universe is expanding the stars would be getting further away from each other as they expand. Some Scientists say there is another force stronger then gravity that is holding the universe together. They think it is the dark matter that is doing this job.
On 'local' scales, such as those within galaxies, gravity fights off the Hubble expansion (universal expansion), and so isn't much at all of a factor, if at all. The Hubble expansion can only be observed on much larger scales, where entire galaxies become 'pinpoints' in comparison.
Also, you wrote "in all four directions"? I think you meant "in every direction".
Astronomers Aim to Grasp Mysterious Dark Matter (In search of WIMPs)
Space.com on Yahoo | 12/29/08 | Clara Moskowitz
Posted on 12/29/2008 2:46:01 PM PST by NormsRevenge
http://www.freerepublic.com/focus/f-chat/2155772/posts
Cosmic-ray hot spots puzzle researchers
- Proton discovery may cast doubt on dark-matter...
Nature News | 26 November 2008 | Philip Ball
Posted on 11/29/2008 1:24:32 PM PST by neverdem
http://www.freerepublic.com/focus/f-chat/2140118/posts
Discovered: Cosmic Rays from a Mysterious, Nearby Object
NASA | Nov 19th, 2008
Posted on 11/20/2008 11:23:12 AM PST by TaraP
http://www.freerepublic.com/focus/f-chat/2135448/posts
Dark star crashes, pouring its light into ashes.
Reason tatters, the forces tear loose from the axis.
Searchlight casting for faults in the clouds of delusion.
Shall we go, you and I while we can
Through the transitive nightfall of diamonds?
Mirror shatters in formless reflections of matter.
Glass hand dissolving to ice petal flowers revolving.
Lady in velvet recedes in the nights of good-bye.
Shall we go, you and I while we can
Through the transitive nightfall of diamonds?
And in Positron Emission Tomography scanners at your local cancer hospital.
/
Yea, I was hoping that would cover it all. :-)
I had not read that yet about the hubble.
Thanks,
Stars inside galaxies maintain their distance from each other by being in common rotation around a central core.
But the distance between galaxies is increasing. That’s what “expanding universe” means.
The distance between earth and other stars in our galaxy isn’t increasing, but the distance between our galaxy and all other galaxies is increasing.
And, it’s increasing at an increasing rate.
The rate of expansion is getting bigger.
The expansion not only shows no signs of slowing down, but seems instead to be speeding up.
It seems to any observer in any galaxy that his galaxy is “at the center of the universe” because the expanding universe is not like the expansion of an exploding powder keg but rather the expansion of space itself.
I'd like to a little of the Mind Of God.
But we presumably live in a universe now in which the overall net mass is thought dark matter. Why wouldn't it seem to so interact now? HAPPY NEW YEAR, ALL!
thanks!
So, my next neantherthal-recessive question is, are blackholes a two-way machine? is a black hole a dark matter (WIMP) consumer AND generator? could the ejected plasma/matter/dust combo ( plasma's sanitizing, de-isotoping and/or ‘etching’ effects on objects it encounters as it travels out hundreds of light years) create conditions for (re)formation (bonding) of WIMPS, replenishing/increasing the dark matter in the universe?
I'm not sure how all this fits together, but plasma jets created on earth from gases, have sanitizing and anti-radiation properties (degrading radio isotopes)
http://www.p2pays.org/ref/14/0_initiatives/init/spring01/plasma.htm
and also of etching surfaces to enhance bonding:
http://www.corotec.com/products/product3.html?id=1138127088
according to this article, the black hole ejects matter into the plasma stream - would that matter be de-isotoped by the plasma?:
http://uk.reuters.com/article/scienceNews/idUKN2338757920080423?sp=true
“”A black hole is a concentration of mass so dense that little can escape its gravitational pull. Aller said in a telephone interview that as objects fall into the black hole, others get shot out at very high velocities.”
according to this article, it must be pretty extreme magnetic field bending for an escape velocity of 99.9% the speed of light (are there sonic booms?):
http://www.sciam.com/article.cfm?id=black-hole-plasma-jets-trace-corkscrew-path
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