The headline
Tuesday, January 15, 2013
"Galaxies have a voracious appetite for fuel "
From the mymymy department, we have
The headline
Galaxies have a voracious appetite for fuel -- in this case, fresh gas -- but astronomers have had difficulty finding the pristine gas that should be falling onto galaxies.
The headline
Wednesday, January 9, 2013
Dark Matter Mysteries Deepen
Wired has a nice article on recent research reporting surprising observations that may relate to dark matter. A brief excerpt:
..
. dark matter is thought to barely interact with itself. The dark matter should just coast through itself and move at the same speed as the hardly interacting galaxies. Instead, it looks [with the recent observations] like the dark matter is crashing into something — perhaps itself – and slowing down faster than the galaxies are. But this would require the dark matter to be able to interact with itself in a completely new an unexpected way, a “dark force” that affects only dark matter. This would be a new fundamental force of the universe, in addition to the four known forces: gravity, electromagnetism, and the strong and weak forces.
...[If this new property is correctly supposed] in particular it would help solve the core/cusp problem, an outstanding mystery seen in dwarf galaxies and star clusters. If dark matter only feels the force of gravity, it should tend to clump in the center of these objects. But astronomers over and over observe the opposite: The dark matter in dwarf galaxies and star clusters is evenly distributed. If dark matter can interact through some sort of dark force, it can bump into itself and puff out, like a hot gas.
..
. dark matter is thought to barely interact with itself. The dark matter should just coast through itself and move at the same speed as the hardly interacting galaxies. Instead, it looks [with the recent observations] like the dark matter is crashing into something — perhaps itself – and slowing down faster than the galaxies are. But this would require the dark matter to be able to interact with itself in a completely new an unexpected way, a “dark force” that affects only dark matter. This would be a new fundamental force of the universe, in addition to the four known forces: gravity, electromagnetism, and the strong and weak forces.
...[If this new property is correctly supposed] in particular it would help solve the core/cusp problem, an outstanding mystery seen in dwarf galaxies and star clusters. If dark matter only feels the force of gravity, it should tend to clump in the center of these objects. But astronomers over and over observe the opposite: The dark matter in dwarf galaxies and star clusters is evenly distributed. If dark matter can interact through some sort of dark force, it can bump into itself and puff out, like a hot gas.
Tuesday, January 8, 2013
Evidence of Gamma ray bursts still puzzling
From an article reposted in spaceref we find that although --
Theorists expect gamma-ray outbursts occur only in close proximity to a galaxy's central black hole, the powerhouse ultimately responsible for the activity...[, a] few rare observations suggested this is not the case.
The 2011 flares from a galaxy known as 4C +71.07 now give astronomers the clearest and most distant evidence that the theory still needs some work. The gamma-ray emission originated about 70 light-years away from the galaxy's central black hole.
Theorists expect gamma-ray outbursts occur only in close proximity to a galaxy's central black hole, the powerhouse ultimately responsible for the activity...[, a] few rare observations suggested this is not the case.
The 2011 flares from a galaxy known as 4C +71.07 now give astronomers the clearest and most distant evidence that the theory still needs some work. The gamma-ray emission originated about 70 light-years away from the galaxy's central black hole.
Thursday, January 3, 2013
A Coherent Pathway
Quoting from a preview of an article in Cell:
A coherent pathway which starts from no more than rocks, water and carbon dioxide and leads to the emergence of the strange bioenergetic properties of living cells has been traced for the first time in a major hypothesis paper in Cell this week.
The preview we link to goes into detail about these latest ideas on the origin of life.
How was the early earth warm enough for life to develop
The evidence for these two facts about the early Earth–a dim sun and liquid oceans–were already strong in the 1960s.
Various solutions are reviewed in this National Geographic article; none so far has majority acceptance among scientists.
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