Dark Matter --"The Tip of an Iceberg of Another World Unrelated to Ours" --New I
- An interesting post about dark matter from The Daily Galaxy.
Sent: 4/27/2013 6:25:30 P.M. Eastern Daylight Time
Subj: The Daily Galaxy: News from Planet Earth & Beyond
_The Daily Galaxy: News from Planet Earth & Beyond_
_Dark Matter --"The Tip of an Iceberg of Another World Unrelated to Ours"
--New Insights _
Posted: 27 Apr 2013 08:39 AM PDT
Answering the observation that the dark matter particle might not be
detectable at a colloquium organized by the Kavli Institute for Cosmological
Physics at the University of Chicago, _Michael Turner_
(http://en.wikipedia.org/wiki/Michael_Turner_(cosmologist)) , a theoretical cosmologist trained in
both particle physics and astrophysics who coined the term “dark energy,”
said that for 20 to 30 years, this idea that dark matter is part of a
unified theory has been our Holy Grail and has led to the WIMP hypothesis and
the belief that the dark matter particle is detectable. "But there’s a new
generation of physicists that is saying, 'Well, there's an alternative view.
Dark matter is actually just the tip of an iceberg of another world that is
unrelated to our world. And I cannot even tell you about that world. There
are no rules for that other world, at least that we know of yet."Ten years
ago," Turner says, "I don't think you would've found astronomers,
cosmologists, and particle physicists all agreeing that dark matter was really
important. And now, they do. And all of them believe we can solve the problem
soon. It's wonderful listening to particle physicists explain the evidence
for dark matter, and vice versa –astronomers explaining _WIMPs_
(http://en.wikipedia.org/wiki/Weakly_interacting_massive_particles) as dark matter. "
"As cosmologists," said _Rocky Kolb_
(http://en.wikipedia.org/wiki/Edward_Kolb) , who studies the application of _elementary-particle physics_
(http://en.wikipedia.org/wiki/Particle_physics) to the very early Universe, and is
the co-author with Michael Turner of The Early Universe, the standard
textbook on particle physics and cosmology, "one of our jobs is to understand
what the universe is made of. To a good approximation, the galaxies and
other structures we see in the universe are made predominantly of dark matter.
We have concluded this from a tremendous body of evidence, and now we need
to discover what exactly is dark matter. The excitement now is that we are
closing in on an answer, and only once in the history of humans will
someone discover it. "
"Nothing in cosmology makes sense without dark matter, says Turner. "We
needed it to form galaxies, stars and other structures in the Universe. And
so it's absolutely central to cosmology. We also know that none of the
particles known to exist can be the dark matter particle. So it has to be a new
particle of nature. Remarkably, our most conservative hypothesis right now
is that the dark matter is a new form of matter – out there to be
discovered and to teach us about particle physics."
"Dark matter is absolutely central to cosmology, said Turner, "and the
evidence for it comes from many different measurements: the amount of
deuterium produced in the big bang, the cosmic microwave background, the formation
of structure in the Universe, galaxy rotation curves, gravitational
lensing, and on and on."
"There is five times more dark matter than ordinary matter, and its
existence allows us to understand the history of the universe beginning from a
formless particle soup until where we are today," said Turner. "If you said,
'You no longer have dark matter,' our current _cosmological model_
(http://en.wikipedia.org/wiki/Physical_cosmology) would collapse. We would be back
to square one."
"Dark matter particles, or WIMPs," said Turner, "don’t interact with
ordinary matter often. It's taken 25 years to improve the sensitivity of our
detectors by a factor of a million, and now they have a good shot at detecting
the dark matter particles. Because of the technological developments, we
think we are on the cusp of a direct detection.
"Likewise for indirect detection. We now have instruments like the Fermi
satellite (the _Fermi Gamma-ray Space Telescope_
(http://fermi.gsfc.nasa.gov/) ) and the IceCube detector (the _IceCube Neutrino Observatory_
5556 (IceCube%20Neutrino%20Observatory)&t=h) at the South Pole, above)
that can detect the ordinary particles (positrons, gamma rays or neutrinos)
that are produced when dark matter particles annihilate, indirectly allowing
dark matter to be detected. IceCube is big enough to detect neutrinos that
are produced by dark matter annihilations in the sun."
Sadly, this point of view could be correct and might mean the solution to
the _dark matter problem_ (http://en.wikipedia.org/wiki/Dark_matter) is
still very far away, that discovering what dark matter actually is could be
100 years away.
The Daily Galaxy via http://www.kavlifoundation.org and AFP 2013 Related
in on the Mystery of Dark Matter --"We are on the Verge of Detecting a New
Particle of Nature"_
s-of-the-higgs-bos.html) _News Alert: LHC Data Confirms Higgs Boson --"But
Is it the Standard Model or Something Beyond?"_
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