2016-06-02. Universe expanding faster than expected.
By Robert Sanders, UC Berkeley News.
2015-10-22. Hubble spies Big Bang frontiers.
NASA heic1523 — Science Release.
2015-06-17. Traces of Earliest Stars That Enriched Cosmos Are Spied.
By Dennis Overbye, New York Times.
2014-09-03. The Laniakea supercluster of galaxies. For GSS A Changing Cosmos chapter 9. Abstract excerpt: Galaxies congregate in clusters and along filaments, and are missing from large regions referred to as voids. These structures are seen in maps derived from spectroscopic surveys that reveal networks of structure that are interconnected with no clear boundaries. Extended regions with a high concentration of galaxies are called ‘superclusters’, although this term is not precise. ...We define a supercluster to be the volume within such a surface, and so we are defining the extent of our home supercluster, which we call Laniakea.... http://www.nature.com/nature/journal/v513/n7516/full/nature13674.html. By R. Brent Tully et al, Nature 513. See also article in Huffington Post - http://www.huffingtonpost.com/2014/09/05/laniakea-supercluster-galaxy-tully_n_5763274.html
2014-03-17. Gravitational Waves from Big Bang Detected. Excerpt:
Physicists have found a long-predicted twist in light from the big bang
that represents the first image of ripples in the universe called
gravitational waves, researchers announced today. The finding is direct
proof of the theory of inflation, the idea that the universe expanded
extremely quickly in the first fraction of a nanosecond after it was
born. What’s more, the signal is coming through much more strongly than
expected, ruling out a large class of inflation models and potentially
pointing the way toward new theories of physics, experts say. “This
is huge,” says Marc Kamionkowski...“It’s not every day that you wake up
and find out something completely
new about the early universe. To me this is as Nobel Prize–worthy as it
gets.” ...researchers have reported a surprisingly large number for r,
the ratio of the gravitational wave fluctuations in the CMB to the
fluctuations caused by perturbations in the density of matter. ...Such a
high value of r, for instance, indicates that inflation
began even earlier than some models predicted, at one trillionth of a
trillionth of a trillionth of a second after the big bang. The timing of inflation, in turn, tells physicists about the energy
scale of the universe when inflation was going on. BICEP2’s value of r
suggests that this was the same energy scale at which all the forces of
nature except gravity (the electromagnetic, strong and weak forces)
might have been unified into a single force—an idea called grand unified
theory. The finding bolsters the idea of grand unification and rules
out a number of inflation models that do not feature such an energy
scale. ...“This measurement is allowing us to use the early universe as a lab for
new physics in energy ranges that are otherwise inaccessible to us,”
Kamionkowski says. http://www.scientificamerican.com/article/gravity-waves-cmb-b-mode-polarization/. Clara Moskowitz, Scientific American. See also: http://www.nytimes.com/2014/03/18/science/space/detection-of-waves-in-space-buttresses-landmark-theory-of-big-bang.html and http://www.nytimes.com/2014/03/25/science/space/ripples-from-the-big-bang.html
2013-10-25. Earliest Known Galaxy Formed Stars at a Breakneck Pace. Excerpt: In the beginning was the big bang; then, hundreds of millions of years later, the universe was full of galaxies. This week, astronomers report taking another step into the unexplored time in between: They have imaged the earliest galaxy yet, dating from just 700 million years after the big bang. The galaxy—one of dozens imaged in a Hubble Space Telescope survey designed to pick up faint, distant galaxies—is aglow with hot, newborn stars, the researchers say, pointing to a rate of star formation that they estimate to be a hundred times that of the modern Milky Way. The find may offer a glimpse of an unexpected period of frenetic star birth in the early universe.... http://www.sciencemag.org/content/342/6157/411.short. Yudhijit Bhattacharjee, Science.
2013-03-20. Planck Mission Brings Universe into Sharp Focus | NASA RELEASE: 13-079. Excerpt: ...The Planck space mission has released the most accurate and detailed map ever made of the oldest light in the universe, .... The map results suggest the universe is expanding more slowly than scientists thought, and is 13.8 billion years old, 100 million years older than previous estimates. The data also show there is less dark energy and more matter, both normal and dark matter, in the universe than previously known. ...Planck launched in 2009 and has been scanning the skies ever since, mapping the cosmic microwave background, the afterglow of the theorized big bang that created our universe. This relic radiation provides scientists with a snapshot of the universe 370,000 years after the big bang. Light existed before this time, but it was locked in a hot plasma similar to a candle flame, which later cooled and set the light free. ...The newly estimated expansion rate of the universe, known as Hubble's constant, is 67.15 plus or minus 1.2 kilometers/second/megaparsec. ...The new estimate of dark matter content in the universe is 26.8 percent, up from 24 percent, while dark energy falls to 68.3 percent, down from 71.4 percent. Normal matter now is 4.9 percent, up from 4.6 percent. ...For more information about Planck, visit: http://www.nasa.gov/planck and http://www.esa.int/Our_Activities/Space_Science/Planck .... See full article at http://www.nasa.gov/home/hqnews/2013/mar/HQ_13-079_Planck_Mission.html.
2008 Aug 18. The Struggle to Measure Cosmic Expansion. By DENNIS OVERBYE, NY Times. Excerpt:
Hoping to understand why the universe seems to be coming apart at its
seams, a young astronomer and his colleagues have embarked on one of
the oldest quests in cosmology, to measure how fast the universe is
growing, how big it is and how old it is. That information is encoded
in the value of an elusive number known as the Hubble constant that has
led astronomers on a merry chase for three-quarters of a century. "It
is the most fundamental number in cosmology," said Adam Riess, 38, an
astronomer at the Space Telescope Science Institute and Johns Hopkins
University, and one of the discoverers 10 years ago that some kind of
"dark energy" is speeding up the expansion of the universe.
This spring, in what he called "a triumph of metrology," Dr. Riess
announced that he and his comrade, Lucas Macri of Texas A&M
University, had used the Hubble Space Telescope to make the newest and
most precise measurement yet of this parameter.
Expressed in the quaint terms astronomers favor, the Hubble constant,
Dr. Riess reported, is 74 kilometers per second per megaparsec. It
means that for every additional million parsecs (about 3.26 million
light-years) a galaxy is from us, it is going 74 kilometers per second
faster. ... with...an uncertainty of only 4.3 percent.
Only 30 years ago, distinguished astronomers could not agree within a
factor of two on the value of Hubble's constant, leaving every other
parameter in cosmology uncertain by at least the same factor and
provoking snickers from other fields of science.
...Dr. Riess's distance ladder has only three rungs and one telescope,
leaping from the Milky Way's neighborhood to supernova explosions as
distant as a billion light-years.
It starts with a galaxy known as NGC 4258 (a k a Messier 106 in Ursa
Major), where astronomers have found clouds emitting radio waves at a
frequency characteristic of water vapor circling the center of the
galaxy, as well as the all-important Cepheid stars. By tracking the
speeds and motion across the sky of these clouds with high resolution
radio observations, a team led by James Herrnstein of the National
Radio Astronomy Observatory in Socorro, N.M., in 1999 determined its
distance as 23.5 million light-years.
Knowing the distance to that galaxy allowed Dr. Riess and his team to
calibrate the Cepheids, which they then used to calibrate supernovas....
2008 May. Underground Astronomy. By Kathleen M. Wong, ScienceMatters@Berkeley. Excerpt:
Most scientists who study the cosmos keep their eyes fastened firmly on
the sky. Not so Bernard Sadoulet. A Berkeley professor of physics,
Sadoulet is stalking dark matter, the elusive material that forms the
scaffolding of the universe. And the place he's laid his traps is just
as shadowy-a former iron mine more than 2,300 feet underground.
Speculations about dark matter's identity range from the side effects
of additional dimensions to ultralight particles known as neutrinos.
But several lines of thinking have converged on heavy particles known
as WIMPs (weakly interacting massive particles).
"If these particles are the dark matter, they form a dark halo around
the galaxy. We are in this halo, and there are billions of these
particles going through us all the time," Sadoulet says.
Sadoulet leads an experiment to find these particles within Minnesota's
Soudan Mine. His Cryogenic Dark Matter Search employs detectors made of
silicon or germanium crystals cooled to nearly absolute zero.
"Within five years, three totally different approaches to catching
WIMPS should be in operation, and we may be at the brink of a
discovery" says Sadoulet. "It's an interesting time to be searching for
2008 Jan 4. NASA Scientists Identify Smallest Known Black Hole. NASA Release No. 08-28. Excerpt:
GREENBELT, Md. - Using a new technique, two NASA scientists have
identified the lightest known black hole. With a mass only about 3.8
times greater than our Sun and a diameter of only 15 miles, the black
hole lies very close to the minimum size predicted for black holes that
originate from dying stars.
"This black hole is really pushing the limits. For many years
astronomers have wanted to know the smallest possible size of a black
hole, and this little guy is a big step toward answering that
question," says lead author Nikolai Shaposhnikov of NASA's Goddard
Space Flight Center in Greenbelt, Md.
...lowest-mass known black hole belongs to a binary system named XTE J1650-500...
Articles from 2008–present
Mysteries of the Cosmos - a panel discussion with astronomers Phil Plait,
Mike Brown, Debra Fischer, Andrea Ghez, and
Saul Perlmutter. Topics: newly discovered solar
system objects; the black hole in our galaxy;
expansion of our universe.