9. Cosmos Begins & Ends


Non-chronological links:

The 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.

2020-10-28. The universe teems with weird black holes, gravitational wave hunters find. By Adrian Cho, Science Magazine. Excerpt: Less than 5 years ago, physicists rocked the scientific world when they first spotted gravitational waves—fleeting ripples in space and time—set off when two gargantuan black holes billions of light-years away swirled into each other. Since then, scientists have detected a scad of similar events, mostly reported event by event. Today, however, researchers with a global network of gravitational wave detectors announced the first major statistical analyses of their data so far, 50 events in all. Posted online in four papers, the analyses show that black holes—ghostly ultraintense gravitational fields left behind when massive stars collapse—are both more common and stranger than expected. They also shed light on mysteries such as how such black holes pair up before merging.... [https://www.sciencemag.org/news/2020/10/universe-teems-weird-black-holes-gravitational-wave-hunters-find

2020-08-12. Extremely young galaxy is Milky Way look-alike. By Science Daily. Excerpt: Astronomers using the Atacama Large Millimeter/submillimeter Array (ALMA), in which the European Southern Observatory (ESO) is a partner, have revealed an extremely distant and therefore very young galaxy that looks surprisingly like our Milky Way. The galaxy is so far away its light has taken more than 12 billion years to reach us: we see it as it was when the Universe was just 1.4 billion years old. It is also surprisingly unchaotic, contradicting theories that all galaxies in the early Universe were turbulent and unstable. This unexpected discovery challenges our understanding of how galaxies form, giving new insights into the past of our Universe. "This result represents a breakthrough in the field of galaxy formation, showing that the structures that we observe in nearby spiral galaxies and in our Milky Way were already in place 12 billion years ago," says Francesca Rizzo, PhD student from the Max Planck Institute for Astrophysics in Germany, who led the research published today in Nature [https://www.nature.com/articles/s41586-020-2572-6].... [https://www.sciencedaily.com/releases/2020/08/200812115304.htm]  

2020-08-11. This is the way the universe ends: not with a whimper, but a bang. By Adam Mann, Science Magazine. Excerpt: In the unimaginably far future, cold stellar remnants known as black dwarfs will begin to explode in a spectacular series of supernovae, providing the final fireworks of all time. That’s the conclusion of a new study, which posits that the universe will experience one last hurrah before everything goes dark forever. ...The known laws of physics suggest that by about 10100 (the No. 1 followed by 100 zeros) years from now, star birth will cease, galaxies will go dark, and even black holes will evaporate through a process known as Hawking radiation, leaving little more than simple subatomic particles and energy. The expansion of space will cool that energy nearly to 0 kelvin, or absolute zero, signaling the heat death of the universe and total entropy. ...The particles in a white dwarf stay locked in a crystalline lattice that radiates heat for trillions of years, far longer than the current age of the universe. But eventually, these relics cool off and become a black dwarf. ...over long time periods, quantum mechanics allows particles to tunnel through energetic barriers, meaning fusion can still occur, albeit at extremely low rates. When atoms such as silicon and nickel fuse toward iron, they produce positrons, the antiparticle of an electron. These positrons would ever-so-slowly destroy some of the electrons in a black dwarf’s center and weaken its degeneracy pressure. For stars between roughly 1.2 and 1.4 times the Sun’s mass—about 1% of all stars in the universe today—this weakening would eventually result in a catastrophic gravitational collapse that drives a colossal explosion similar to the supernovae of higher mass stars, Caplan reports this month in the Monthly Notices of the Royal Astronomical Society. Caplan says the dramatic detonations will begin to occur about 101100 years from now, a number the human brain can scarcely comprehend. The already unfathomable number 10100 is known as a googol, so 101100 would be a googol googol googol googol googol googol googol googol googol googol googol years. The explosions would continue until 1032000 years from now, which would require most of a magazine page to represent in a similar fashion.... [https://www.sciencemag.org/news/2020/08/way-universe-ends-not-whimper-bang

2020-04-24. Hubble Marks 30 Years of Seeing a Universe Being Born and Dying. By Dennis Overbye, The New York Times. Excerpt: As shown in a new picture of stormy star birth in a nearby galaxy, captured by the Hubble Space Telescope, the cosmos is keeping up the tradition of both birth and death. Stars are being born out of the ashes of old ones, forever refreshing the universe. The picture was released Friday by the Space Telescope Science Institute in Baltimore, keepers of the Hubble, in honor of the 30th anniversary of the launch of that telescope on April 24, 1990.... [https://www.nytimes.com/2020/04/24/science/hubble-telescope-30th-birthday.html

2020-03-06. This Black Hole Blew a Hole in the Cosmos. By Dennis Overbye, The New York Times. Excerpt: If there were ever sentient beings in the Ophiuchus cluster, a faraway conglomeration of galaxies in the southern sky, they are long gone. A few hundred million years ago, a mighty cosmic storm swept through that region of space. Hot gas suffuses the cluster, but the storm blew a crater through it more than a million light-years wide, leaving just a near-vacuum, a nattering haze of ultrahot electrical particles. The culprit, astronomers suspect, was a gigantic outburst of energy from a supermassive black hole — the biggest explosion ever documented in the universe, according to Simona Giacintucci, a radio astronomer at the Naval Research Laboratory and the leader of the research team.... [https://www.nytimes.com/2020/03/06/science/black-hole-cosmos-astrophysics.html

2019-04-10. The first picture of a black hole opens a new era of astrophysics. By Lisa Grossman and Emily Conover, ScienceNews. 

2018-10-31. This ball of gas is racing around the black hole at our galaxy’s heart. By Daniel Clery, Science Magazine. 

2018-10-29. Move over, Hubble: Discovery of expanding cosmos assigned to little-known Belgian astronomer-priest. By Daniel Clery, Science Magazine. 

2018-05-01. Gaia’s Map of 1.3 Billion Stars Makes for a Milky Way in a Bottle. By Dennis Overbye, The New York Times. 

2017-10-16. LIGO Detects Fierce Collision of Neutron Stars for the First Time. By Dennis Overbye, The New York Times. 

2017-06-28. Greetings, E.T. (Please Don’t Murder Us). By Steven Johnson, The New York Times. 

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 dark matter."

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...