An Introductory Approach to Physical Cosmology as a Means of Understanding the Universe

The Cosmic Microwave Background temperature fluctuations from the 5-year Wilkinson Microwave Anisotropy Probe data seen over the full sky. The average temperature is 2.725 Kelvin (degrees above absolute zero; absolute zero is equivalent to -273.15 C or -459 F

 "Observations suggest that the universe as we know it began around 13.7 billion years ago. Since then, the evolution of the universe has passed through three phases. The very early universe, which is still poorly understood, was the split second in which the universe was so hot that particles had energies higher than those currently accessible in particle accelerators on Earth. Therefore, while the basic features of this epoch have been worked out in the big bang theory, the details are largely based on educated guesses.

"Following this, in the early universe, the evolution of the universe proceeded according to known high energy physics. This is when the first protons, electrons and neutrons formed, then nuclei and finally atoms. With the formation of neutral hydrogen, the cosmic microwave background was emitted. Finally, the epoch of structure formation began, when matter started to aggregate into the first stars and quasars, and ultimately galaxies, clusters of galaxies and superclusters formed. The future of the universe is not yet firmly known, but according to the ΛCDM model it will continue expanding forever," according to Wikipedia.

The above illustration addresses "Physical cosmology, as a branch of astronomy," which concerns "the study of the largest-scale structures and dynamics of our universe and is concerned with fundamental questions about its formation and evolution.[1] Cosmology involves itself with studying the motions of the celestial bodies and the first cause. For most of human history, it has been a branch of metaphysics and religion. Cosmology as a science originates with the Copernican principle, which implies that celestial bodies obey identical physical laws to those on earth, and Newtonian mechanics, which first allowed us to understand those motions. This is now called celestial mechanics. Physical cosmology, as it is now understood, began with the twentieth century development of Albert Einstein's general theory of relativity and better astronomical observations of extremely distant objects.

"The twentieth century advances made it possible to speculate about the origins of the universe and allowed scientists to establish the Big Bang as the leading cosmological model, which most cosmologists now accept as the basis for their theories and observations. Vanishingly few researchers still advocate any of a handful of alternative cosmologies, but professional cosmologists generally agree that the big bang best explains observations. Physical cosmology, roughly speaking, deals with the very largest objects in the universe (galaxies, clusters and superclusters), the very earliest distinct objects to form (quasars) and the very early universe, when it was nearly homogeneous (hot big bang, cosmic inflation, cosmic microwave background radiation and the Weyl curvature hypothesis).

"Cosmology is unusual in physics for drawing heavily on the work of particle physicists' experiments, and research into phenomenology and even string theory; from astrophysicists; from general relativity research; and from plasma physics. Thus, cosmology unites the physics of the largest structures in the universe with the physics of the smallest structures in the universe," according to Wikipedia.



"Light elements, primarily hydrogen and helium, were created in the Big Bang. These light elements were spread too fast and too thinly in the Big Bang process (see nucleosynthesis) to form the most stable medium-sized atomic nuclei, like iron and nickel. This fact allows for later energy release, as such intermediate-sized elements are formed in our era. The formation of such atoms powers the steady energy-releasing reactions in stars, and also contributes to sudden energy releases, such as in novae. Gravitational collapse of matter into black holes is also thought to power the most energetic processes, generally seen at the centers of galaxies (see quasars and in general active galaxies).

"Cosmologists are still unable to explain all cosmological phenomena purely on the basis of known conventional forms of energy, for example those related to the accelerating expansion of the universe, and therefore invoke a yet unexplored form of energy called dark energy[2] to account for certain cosmological observations. One hypothesis is that dark energy is the energy of virtual particles (which mathematically must exist in vacuum due to the uncertainty principle).

"There is no unambiguous way to define the total energy of the universe in the current best theory of gravity, general relativity. As a result it remains controversial whether one can meaningfully say that total energy is conserved in an expanding universe. For instance, each photon that travels through intergalactic space loses energy due to the redshift effect. This energy is not obviously transferred to any other system, so seems to be permanently lost. Nevertheless some cosmologists insist that energy is conserved in some sense" according to Wikipedia.

"Thermodynamics of the universe is a field of study to explore which form of energy dominates the cosmos - relativistic particles which are referred to as radiation, or non-relativistic particles which are referred to as matter. The former are particles whose rest mass is zero or negligible compared to their energy, and therefore move at the speed of light or very close to it; the latter are particles whose kinetic energy is much lower than their rest mass and therefore move much slower than the speed of light.

"As the universe expands, both matter and radiation in it become diluted. However, the universe also cools down, meaning that the average energy per particle is getting smaller with time. Therefore the radiation becomes weaker, and dilutes faster than matter. Thus with the expansion of the universe radiation becomes less dominant than matter. In the very early universe radiation dictates the rate of deceleration of the universe's expansion, and the universe is said to be 'radiation dominated'. At later times, when the average energy per photon is roughly 10 eV and lower, matter dictates the rate of deceleration and the universe is said to be 'matter dominated'. The intermediate case is not treated well analytically. As the expansion of the universe continues, matter dilutes even further and the cosmological constant becomes dominant, leading to an acceleration in the universe's expansion." according to Wikipedia.



"Modern cosmology developed along tandem observational and theoretical tracks. In 1915, Albert Einstein developed his theory of general relativity. At the time, physicists were prejudiced to believe in a perfectly static universe without beginning or end. Einstein added a cosmological constant to his theory to try to force it to allow for a static universe with matter in it. The so-called Einstein universe is, however, unstable. It is bound to eventually start expanding or contracting. The cosmological solutions of general relativity were found by Alexander Friedmann, whose equations describe the Friedmann-Lemaître-Robertson-Walker universe, which may expand or contract.

"In the 1910s, Vesto Slipher (and later Carl Wilhelm Wirtz) interpreted the red shift of spiral nebulae as a Doppler shift that indicated they were receding from Earth. However, it is notoriously difficult to determine the distance to astronomical objects: even if it is possible to measure their angular size it is usually impossible to know their actual size or luminosity. They did not realize that the nebulae were actually galaxies outside our own Milky Way, nor did they speculate about the cosmological implications.

"In 1927, the Belgian Roman Catholic priest Georges Lemaître independently derived the Friedmann-Lemaître-Robertson-Walker equations and proposed, on the basis of the recession of spiral nebulae, that the universe began with the "explosion" of a "primeval atom"—what was later called the big bang.

"In 1929, Edwin Hubble provided an observational basis for Lemaître's theory. Hubble proved that the spiral nebulae were galaxies and measured their distances by observing Cepheid variable stars. He discovered a relationship between the redshift of a galaxy and its luminosity. He interpreted this as evidence that the galaxies are receding in every direction at speeds (relative to the Earth) directly proportional to their distance. This fact is known as Hubble's law. The relationship between distance and speed, however, was accurately ascertained only relatively recently: Hubble was off by a factor of ten.

 

"Given the cosmological principle, Hubble's law suggested that the universe was expanding. This idea allowed for two opposing possibilities. One was Lemaître's Big Bang theory, advocated and developed by George Gamow. The other possibility was Fred Hoyle's steady state model in which new matter would be created as the galaxies moved away from each other. In this model, the universe is roughly the same at any point in time.

"For a number of years the support for these theories was evenly divided. However, the observational evidence began to support the idea that the universe evolved from a hot dense state. Since the discovery of the cosmic microwave background in 1965 it has been regarded as the best theory of the origin and evolution of the cosmos. Before the late 1960s, many cosmologists thought the infinitely dense singularity at the starting time of Friedmann's cosmological model was a mathematical over-idealization, and that the universe was contracting before entering the hot dense state and starting to expand again. This is Richard Tolman's oscillatory universe. In the sixties, Stephen Hawking and Roger Penrose demonstrated that this idea was unworkable, and the singularity is an essential feature of Einstein's gravity. This led the majority of cosmologists to accept the Big Bang, in which the universe we observe began a finite time ago," according to Wikipedia

Primordial Earth Most Likely Was Populated by Numerous Colonies of Arsenic-Eating Bacteria

Examples of "lowly bacteria found in a foul-smelling hot spring near Mono Lake, California is a living window into Earth’s early history, a time when photosynthesis was barely evolved and the atmosphere non-existent."

Image: Science

The photos above provide evidence that: "Arsenic(III) Fuels Anoxygenic Photosynthesis in Hot Spring Biofilms from Mono Lake, California."

Science Magazine has written that: "Phylogenetic analysis indicates that microbial arsenic metabolism is ancient and probably extends back to the primordial Earth. In microbial biofilms growing on the rock surfaces of anoxic brine pools fed by hot springs containing arsenite and sulfide at high concentrations, we discovered light-dependent oxidation of arsenite [As(III)] to arsenate [As(V)] occurring under anoxic conditions. The communities were composed primarily of Ectothiorhodospira-like purple bacteria or Oscillatoria-like cyanobacteria. A pure culture of a photosynthetic bacterium grew as a photoautotroph when As(III) was used as the sole photosynthetic electron donor. The strain contained genes encoding a putative As(V) reductase but no detectable homologs of the As(III) oxidase genes of aerobic chemolithotrophs, suggesting a reverse functionality for the reductase. Production of As(V) by anoxygenic photosynthesis probably opened niches for primordial Earth's first As(V)-respiring prokaryotes."

That points to the discovery of: "A new kind of photosynthesis that uses arsenic instead of water to harvest light promises to rewrite evolutionary history - at least that of arsenic metabolism on Earth.

It is well known that: "The evolution of efficient, oxygen-based photosynthesis has been hard to explain. Primitive forms gathered energy from light by using it to free electrons from sulphur and iron in an oxygen-free environment. Oxygenic photosynthesis, which involves freeing electrons from water, takes more energy and produces oxygen. But oxygen was deadly to most primitive life on Earth. "The first organisms to do this would die," says Hyman Hartman of the Massachusetts Institute of Technology." This realization has lead some scientists to look to arsenic using bacteria as an answer to this vexing problem because "arsenic metabolism could have evolved much earlier, giving plenty of time for bacteria to diversify."

"Some bacteria use arsenate (a deadly poison) - arsenic with four oxygen atoms attached - as an energy source. It was thought that this form of metabolism didn't get going until long after photosynthesis filled the atmosphere with oxygen about 2.7 billion years ago. When this happened, naturally occurring arsenite would be transformed into arsenate."

"Ronald Oremland and colleagues at the US Geological Survey in Menlo Park, California," believe "arsenic metabolism could have evolved much earlier, giving plenty of time for bacteria to diversify."

"Mono Lake in California, USA NASA Landsat 7 image," Furthermore: "In the warm, bubbling pools of Mono Lake in California, scientists have isolated a bacterium that fuels itself on arsenic."

The team of American scientists explained: "Once you spit out oxygen, all kinds of things arise," said Ronald Oremland, a United States Geological Survey biogeochemist and co-author of the bacteria’s description, published today in Science. "It’s Part One of the evolution of Earth."

Regarding Mono Lake, which lies near the Sierra Nevada mountain range, Dr Oremland explained: "These lakes are fed by hydrothermal waters that leach out arsenic-containing minerals from the surrounding rocks."

The arsenic fueled bacteria "had colonised small, hot pools, forming colourful "biofilms"."

Dr Oremland explained their findings: "We suspected that these bacteria were using arsenic to make a living, so we scraped the biofilms off the rock and studied them under laboratory conditions."

Bacteria living in Mono Lake, California can survive the high levels of arsenic. BBC NEWS

The original study
T.R. Kulp, S.E. Hoeft, M. Asao, M.T. Madigan, J.T. Hollibaugh, J.C. Fisher, J.F. Stolz, C.W. Culbertson, L.G. Miller, R.S. Oremland, Arsenic(III) Fuels Anoxygenic Photosynthesis in Hot Spring Biofilms from Mono Lake, California, Science, 321 (2008) 967-970. DOI: 10.1126/science.1160799

NASA’s Interstellar Boundary Explorer satellite, IBEX, Provides Evidence That a Narrow Ribbon Structure of Densely Packed Neutral Atoms Bounds our Solar System

A map of neutral atoms, generated by NASA's Interstellar Boundary Explorer, shows a ribbonlike structure near the edge of the heliosphere, the boundary between the solar system and interstellar space. The ribbon is not predicted by any model. Blue denotes the lowest intensity of atoms, red the highest.
Credit: Image from Southwest Research Institute

Ron Cowen, writing for the October 16, 2009 edition of ScienceNews reveals that: "New observations reveal a dense ribbon structure that current models don’t explain.

ScienceNews' Cowen summarizes recent observations: "The edge of the solar system is tied up with a ribbon, astronomers have discovered. The first global map of the solar system reveals that its edge is nothing like what had been predicted. Neutral atoms, which are the only way to image the fringes of the solar system, are densely packed into a narrow ribbon rather than evenly distributed."

Herbert Funsten of the Los Alamos National Laboratory in New Mexico, who along with Stephen Fuselier of the Lockheed Martin Advanced Technology Center in Palo Alto, Calif.have produced a paper detailing their findings to which co-author Funsten says: "Our maps show structure and energy spectra that are completely different from what any model has predicted.”

Cowen, of ScienceNews, adds that: "NASA’s Interstellar Boundary Explorer satellite, or IBEX, discovered the narrow ribbon, which completes nearly a full circle across the sky. The density of neutral atoms in the band is two to three times that in adjacent regions.

"IBEX is a NASA mission that will for the first time take a picture of the edge of our solar system. This video explains the way IBEX will create a global map of the boundaries of our solar system. IBEX uses energetic neutral atoms to map these boundaries. The Voyagers spacecraft launched in the 1970s is looking at two points only, while IBEX images the global structure of the boundaries that surround our solar system."

"IBEX will study the interaction between the solar wind and the material beyond our Solar System called the interstellar medium. The solar wind flowing out of the sun inflates a bubble that we call the heliosphere. IBEX's job is to study those boundaries and understand how they really work and tell us how the heliosphere is able to do the important job of protecting us here on Earth as well as astronauts in space from the dangerous galactic cosmic rays."

"These and related findings, reported in six papers posted online October 15 in Science," Cowen explains "will not only send theorists back to the drawing board, researchers say, but may ultimately provide new insight on the interaction between the heliosphere — the vast bubble in which the solar system resides — and surrounding space."

Tom Krimigis of Johns Hopkins University’s Applied Physics Laboratory in Laurel, Md.developes further on the concept of the solar system bounded by a huge bubble explains: "The bubble is inflated by solar wind, the high-speed stream of charged particles blowing out from the sun to the solar system’s very edge. For 48 years, researchers have assumed that the solar wind sculpted the structure at the heliosphere’s boundary with interstellar space."

Theorist Nathan Schwadron of Boston University, a lead author of one of the studies, says: "...the newly found ribbon’s orientation suggests that the galaxy’s magnetic field, just outside the heliosphere, seems to be the chief organizer of structure in this region."

ScienceNews writer Cowen adds that: "It’s not known whether the ribbon lasts for just a few years or is a permanent feature.

He continues: "Equally puzzling are observations of the same boundary region with an instrument on the Cassini spacecraft, which recorded the density of atoms at higher energies, above 6,000 electron volts. From its vantage point at Saturn, Cassini sees a belt rather than a ribbonlike structure, a team led by Krimigis also reports in Science. The belt is substantially broader than the ribbon seen by IBEX but is in the same general area."

Schwadron's observations are summarized by Cowen: "The heliosphere shields the solar system from 90 percent of energetic cosmic rays — high-speed charged particles that would otherwise bombard the planets and harm life. Understanding more about the heliosphere and its ability to filter out galactic cosmic rays could be critical for assessing the safety of human space travel. The new findings may also help predict how the heliosphere varies in shape and size as it moves through the galaxy and encounters regions of space having different densities and magnetic field strengths."

David McComas of the Southwest Research Institute in San Antonio, notes: "The ribbon found by IBEX, recorded at energies between 200 and 6,000 electron volts, is brightest at about 1,000 electron volts and lies between about 100 and 125 astronomical units from the sun." Cowen explains: "One astronomical unit is the distance between the Earth and the sun. The atoms recorded by IBEX, which orbits Earth, took a year or two, depending on their energies, to reach the craft from the outer edge of the heliosphere.

 

Image: Walt Feimer/Goddard Space Flight Center

"The IBEX ribbon runs perpendicular to the direction of the galaxy’s magnetic field at the interstellar boundary, an indication that the field has a much stronger than expected influence on the sun’s environs," Cowen includes that a report (issued by) Schwadron and his colleagues regarding the ribbon adds: "One possibility is that pressure from this external magnetic field has forced particles just inside the heliosphere to bunch together into a ribbon."

“First and foremost, this is a big surprise because we thought we know a lot about this region, the edge of the heliosphere,” McComas says. Cowen cites previous ScienceNews articles and reminds readers that: "The Voyager 1 craft in 2004 (SN: 1/3/04, p. 7) and the Voyager 2 craft in 2007 (SN: 8/2/08, p. 7) journeyed to opposite sides of this fringe region of the solar system and crossed the termination shock — where the solar wind encounters a shock that precedes the influx of particles drifting into the solar system from interstellar space. Both craft recorded the density of particles and the strength of the magnetic fields."

McComas points out: "Both Voyager 1 and 2 missed seeing the newly found ribbon because it spans a region between their flight paths,... No existing model can explain the ribbon, he adds, which was found independently by two instruments on IBEX."

Krimigis notes: "Researchers had assumed that the pressure from the solar wind would compress in the heliosphere in the direction that the solar system was moving through space and create a cometlike tail in the opposite direction." Krimigis adds further perspective: "Now we know that’s wrong..”

Study coauthor Stephen Fuselier of the Lockheed Martin Advanced Technology Center in Palo Alto, Calif., notes: "IBEX has also generated the first maps of neutral hydrogen and oxygen atoms entering the solar system from interstellar space. Previous observations had traced only incoming helium atoms. The sensitivity of the IBEX instruments allowed researchers to record the relatively small number of oxygen atoms that travel from beyond the termination shock, about 16 billion kilometers from Earth, to the spacecraft."

Fuselier adds further: "Hydrogen atoms are more abundant than either helium or oxygen but their low mass means they are easily swept aside by the high-speed solar wind and can’t readily be detected. The sun’s unusually low activity during the current minimum in the solar cycle allowed more of the hydrogen atoms from the outer heliosphere to travel unimpeded to the inner solar system, enabling IBEX to record those atoms."

An artists rendering of IBEX in proximity of a ribbon structure and energy spectra that nearly encircles the solar system.

10/17/09 President Barack Obama Weekly Radio Address

SATURDAY, OCTOBER 17TH, 2009 AT 12:01 AM
Weekly Address: Taking the Insurance Companies on Down the Stretch
Posted by Jesse Lee
As the health insurance reform debate enters into its final stages in Congress, the President denounces the desperate and deceptive last-ditch efforts of the health insurance companies to derail it.

read the transcript

THE WHITE HOUSE

Office of the Press Secretary

________________________________________________
For Immediate Release            October 17, 2009

WEEKLY ADDRESS: President Obama Calls Hails Progress on Health Insurance Reform Despite Defenders of the Status Quo

WASHINGTON – In his weekly address, President Barack Obama praised the progress that has been made on health insurance reform, and spoke out against those who defend the status quo in order to score political points and protect their profits.  With reform the closest it has ever been to becoming law, the insurance companies are rolling out deceptive ads, paying for misleading studies, and flooding Capitol Hill with lobbyists.  Now, Washington needs to serve the American people, not the special interests.

  October 17, 2009 , 10:44 am

The Saturday Word: Health Care Battles

By Janie Lorber

"President Obama defended his health care overhaul against the health insurers with renewed gusto Saturday morning after a week in which insurance companies circulated reports and ran advertisements deeply critical of his plans.

“They’re filling the airwaves with deceptive and dishonest ads. They’re flooding Capitol Hill with lobbyists and campaign contributions. And they’re funding studies designed to mislead the American people,” Mr. Obama said adding firepower to Congressional Democrats’ already hostile responses. “It’s smoke and mirrors. It’s bogus. And it’s all too familiar. Every time we get close to passing reform, the insurance companies produce these phony studies as a prescription and say, “Take one of these, and call us in a decade.”

"His comments were the latest sign that the relationship between insurance companies and the administration has deteriorated after months of cooperation.

"On Friday the White House backed away from restrictions laid in September that prohibited insurance companies from warning Medicare recipients of potential cuts to their program in the health care overhaul. The administration also cited one company in particular, Humana, for violating Medicare rules, saying the company had misled its beneficiaries to derail the plan."

Obama Chastises "Dishonest" Health Insurers

By REUTERS

Published: October 17, 2009

 WASHINGTON (Reuters) - "U.S. President Barack Obama lashed out on Saturday against the "deceptive and dishonest" efforts of health insurance companies, who he said are trying to kill healthcare reform, no matter the cost to the country.

The Democratic president's push to overhaul the $2.5 trillion (1.528 trillion pound) U.S. healthcare industry, his top domestic policy priority, received a big boost this week when the Senate Finance Committee approved its version of a reform measure with the support of Republican Senator Olympia Snowe.

"Many experts expect some version of a healthcare bill will pass this year, but there are still major disagreements on details including whether the measure will include a government-run insurance program, the "public option."

"For the first time ever, all five committees in Congress responsible for health reform have passed a version of legislation," Obama said in his weekly radio address. "As I speak to you today, we are closer to reforming the health care system than we have ever been in history."

"However, he acknowledged the overhaul still must clear significant hurdles before becoming law. "And there are still those who would try to kill reform at any cost," he said.

"The history is clear: for decades rising health care costs have unleashed havoc on families, businesses and the economy. And for decades, whenever we have tried to reform the system, the insurance companies have done everything in their considerable power to stop us."

BATTLE LEAPED IN INTENSITY THIS WEEK

"The battle over reform between angry Democrats and health insurers leaped in intensity when the industry trade group America's Health Insurance Plans issued a report on Monday, on the eve of the finance committee's vote, saying Senate healthcare legislation would lead to increases in annual insurance premiums of as much as $4,000 by 2019.

"Democrats denied the findings, citing a report by the nonpartisan Congressional Budget Office that said the Finance Committee bill would make health coverage affordable to millions of Americans who do not have it and slow the growth of healthcare costs.

"In fact, the insurance industry is rolling out the big guns and breaking open their massive war chest -- to marshal their forces for one last fight to save the status quo," Obama said.

"They're filling the airwaves with deceptive and dishonest ads. They're flooding Capitol Hill with lobbyists and campaign contributions. And they're funding studies designed to mislead the American people," he said.

Democratic leaders in Congress began work this week on merging the various committees' proposals on healthcare while keeping party liberals and moderates -- and Snowe -- happy.

"Senate Republicans demanded Democrats allow more time to debate the details of the sweeping plan. Obama has set the end of the year as his goal for passing a measure that would begin to slow increases in healthcare costs, regulate the insurance market and expand health coverage without increasing the federal budget deficit.

"Health insurers' shares dropped this week after news of the finance committee's vote.

"Obama vowed an overhaul will go through.

"Every time we get close to passing reform, the insurance companies produce these phony studies as a prescription and say, 'Take one of these, and call us in a decade.' Well, not this time," Obama said.

(Editing by Todd Eastham)

Obama Praises Senate Committee's Health Care Vote

By THE ASSOCIATED PRESS 

Published: October 17, 2009 

 

 

 WASHINGTON (AP) -- "Pushing back against his critics, President Barack Obama says overhauling the health care system, while helping millions of people, also will test whether policy makers can ''serve the national interest despite the unrelenting efforts of the special interests.''

"The administration is trying to build momentum for the president's overhaul effort after the Senate Finance Committee voted 14-9 this week for a bill that would extend health care coverage to millions of people. One Republican, Maine Sen. Olympia Snowe, supported the bill, and the measure faces considerable opposition from the health care industry, labor unions and large business organizations.

''The history is clear: For decades rising health care costs have unleashed havoc on families, businesses and the economy,'' the president said Saturday in his weekly radio and Internet address. ''And for decades, whenever we have tried to reform the system, the insurance companies have done everything in their considerable power to stop us.''

"The health insurance industry released a study earlier this week concluding that the Finance Committee bill -- one of five competing House and Senate health care measures -- would raise premiums significantly for millions of people who already have health coverage.

"The report drew intense criticism from the White House, congressional Democrats and other advocates of the bill who deemed the study a last-ditch effort to sway public opinion against the measure.

"Obama said he would not abide ''those who would bend the truth or break it to score political points and stop our progress as a country.'' He accused the industry of ''filling the airwaves with deceptive and dishonest ads,'' sending money and lobbyists to Capitol Hill and paying for studies ''designed to mislead the American people.''

"The insurance industry responded Saturday, saying it supports a comprehensive, bipartisan overhaul of the system but that separate studies recently found that some of the existing proposals will increase significantly health care costs for families and employers.

''Reform needs to work and deliver on the promise made to the American people that everyone will have quality, affordable coverage,'' Karen Ignagni, president of the industry group America's Health Insurance Plans, said in a statement.

"The bills moving through Congress generally would require most Americans to buy insurance, provide federal subsidies to help lower-income people afford coverage and help small businesses defray the cost of extending coverage to their workers.

"The measures would bar insurers from denying coverage because of pre-existing medical conditions and limit their ability to charge higher premiums based on age or family size. Expanded coverage would be paid for by cutting hundreds of billions of dollars from future Medicare payments to health care providers. Higher taxes also are included in the bills.

"Republican opponents say the bills will increase costs for patients, further job losses and give the government more of a say in who gets medical care, and what kind.

''Americans inherently know government interference drives costs up, not down,'' Rep. Kevin Brady, R-Texas, said in the GOP's weekly message. ''The massive health care plans being crafted behind closed doors in Washington will ultimately allow the government to decide what doctors we can see, what treatments the government thinks you deserve and what medicines you can receive.''

 

                                                                                                                                                                                                          White House Photo, Pete Souza_10-17-09

Researchers Investigate the Connection Between the Diminishment of Biodiversity and the Weakening of Global Economic Development

Yellow banded dart frog. Amphibians are facing some of the worst threats to their biodiversity. A report in the journal Science highlights how biodiversity loss is weakening efforts to tackle global poverty.

PHYSORG.COM writes: "Biodiversity loss is undermining global development, leading scientists warn. The paper brings together a broad group of scientists and policy makers, including Natural History Museum plant expert Dr Sandra Knapp."

Global economic development is being threatened by the sustained loss of biodiversity according to a group of respected scientists: Jeffrey D. Sachs, Jonathan E. M. Baillie, William J. Sutherland, Paul R. Armsworth, Neville Ash, John Beddington, Tim M. Blackburn, Ben Collen, Barry Gardiner, Kevin J. Gaston, H. Charles J. Godfray, Rhys E. Green, Paul H. Harvey, Brett House, Sandra Knapp, Noëlle F. Kümpel, David W. Macdonald, Georgina M. Mace, James Mallet, Adam Matthews, Robert M. May, Owen Petchey, Andy Purvis, Dilys Roe, Kamran Safi, Kerry Turner Matt Walpole, Robert Watson, Kate E. Jones who published an article, "Biodiversity Conservation and the Millennium Development Goals," to publish their findings in the September 18, 2009 issue of Science.

The summary that appears in Science condenses the main thrust of the collaborative article: "The Millennium Development Goals (MDGs) are designed to inspire efforts to improve people's lives by, among other priorities, halving extreme poverty by 2015 (1). Analogously, concern about global decline in biodiversity and degradation of ecosystem services (2) gave rise in 1992 to the Convention on Biological Diversity (CBD). The CBD target "to achieve by 2010 a significant reduction of the current rate of biodiversity loss" was incorporated into the MDGs in 2002. Our lack of progress toward the 2010 target (3, 4) could undermine achievement of the MDGs and poverty reduction in the long term. With increasing global challenges, such as population growth, climate change, and overconsumption of ecosystem services, we need further integration of the poverty alleviation and biodiversity conservation agendas."

The main thrust of the article argues that "Biodiversity loss is undermining global development."

The authors of the article explain that: "Goals set to alleviate extreme poverty will not be met unless we address the accelerating rate of biodiversity loss,.., and new achievable targets are needed urgently."

The authors of the study contend that: "Poverty and environmental degradation have many of the same fundamental causes, such as the pressures of unsustainable human population growth."

The group of authors are in accord that: "More research is needed into the links between biodiversity and poverty, the team says, so that better decisions can be made about how the environment is used in future. The outcomes should benefit both poverty alleviation and conservation."

‘Degradation of the natural diversity of our planet will inevitably bring problems for our own species,’ says Dr Sandra Knapp.

Dr Knapp explains, ‘The integration of conservation and development goals will be difficult, and will require new interactions between scientific communities and with the public at large’.

‘We hope the newly opened Darwin Centre at the Natural History Museum can be a focal point for discussion of issues that confront all of us as we integrate the Millennium Development Goals with our concern for the natural world,’ Dr Knapp concluded.

PHYSORG.COM explains that: "The 8 Millennium Development Goals were agreed by all the world’s countries and one of the goals is to halve extreme poverty by 2015. The Convention on Biological Diversity, signed by 150 governments at the 1992 Rio Earth Summit, is dedicated to promoting sustainable development. However, the goals of both of these will not be met unless humans begin living in a more sustainable way."

Dr Kate Jones, Senior Research Fellow at ZSL concludes: ‘The global issues are now so intense we will only succeed if we have an integrated environment and development agenda - our children’s environment is an essential part of their welfare.’

Provided by American Museum of Natural History (news : web)

Global development and biodiversity

Scientists Feel Confident That They Have Finally determined that the flatworm Acoelomorpha Belongs as a Sister Clade to Other Bilateral Animals

An international research team led by Brown University has determined that the flatworm Acoelomorpha belongs as a sister clade to other bilateral animals. The finding means the worm is a product of the deepest split within the bilateral animals, the first evolutionary divergence within the group. 

Credit: Eric Rottinger/Kahikai.org

An article in PHYSORG.COM explains: "When it comes to understanding a critical junction in animal evolution, some short, simple flatworms have been a real thorn in scientists' sides. Specialists have jousted over the proper taxonomic placement of a group of worms called Acoelomorpha. This collection of worms, which comprises roughly 350 species, is part of a much larger group called bilateral animals, organisms that have symmetrical body forms, including humans, insects and worms. The question about acoelomorpha, was: Where do they fit in?"

Acoelomorpha, the most primitive bilateral animals, has held the fascination of researchers for a number of years. It as been referred to as an "enigmatic,... rogue animal,." As it has been studied: "It has been wandering throughout the animal tree of life," said Casey Dunn, an evolutionary biologist at Brown University. Acoelomorpha are "tiny, cryptic worms that many consider to be the most primitive of all bilaterally symmetrical animals."

  

Acoelomorpha, a tiny, primitive flatworm

The reason why Acoelomorpha are a disputed phylum of animals with planula-like features (free-swimming or crawling larval type common in many species of the phylum Cnidaria (e.g., jellyfish, corals, and sea anemones). The Acoelomorpha has recently been classified by Jaume Baguñà and Marta Riutort as a separate phylum, basal, forming a basis; fundamental; basic form among the Bilateria."There are two or more superphyla (main lineages) of Bilateria" including ... "the protostomes (which) include most of the rest, such as arthropods, annelids, mollusks, flatworms, and so forth.... There are a number of differences, most notably in how the embryo develops. In particular, the first opening of the embryo becomes the mouth in protostomes."

Acoelomorpha are very primitive flatworms

PHYSORG.COM explains: "The worm wanders no more. Through a laborious genetic sequencing analysis, Dunn and an international team of scientists have settled the long-standing debate and determined that acoelomorpha belongs as a sister clade to other bilateral animals. The finding is significant, Dunn said, because it shows the worm is a product of the deepest split within the bilateral animals, the first evolutionary divergence within the group. Because of that, scientists have gained a key insight into the most recent common ancestor to bilaterians, a species that remains unknown.

The flatworm is "as distant as an animal can be in bilateria and still be a bilaterian," said Dunn, "So, now we have two perspectives to (find out about) this common ancestor, the acoelomorphs and all the other bilateral animals."

A team of 17 scientists from the United States, France Germany, Sweden, Spain and the United Kingdom, published the results of their research recently in the Proceedings of the Royal Society B, and produced two interesting findings that stood out:

"The debate appears to be over for Xenoturbella, a type of marine worm whose ancestral affiliation had been tossed between worms and mollusks. The researchers reported their genetic analysis shows diminishing evidence for placing xenoturbella within Deuterostomia, one of the major groups within the animal kingdom. Coincidentally, it also shows that xenoturbella may be a close relative to acoelomorpha.

"Cycliophora, a single species discovered in 1994 that lives on the bristles surrounding the mouth of the Norway lobster Nephrops norvegicus, has found a home with Entoprocta and Ectoprocta. The researchers base their findings on an analysis that reached further into the genetic makeup of cycliophora than previous studies had done."

"The team used a genetic sequencing technique called expressed sequence tags to carry out the phylogenetic studies. The aim of this approach, discussed in a study led by Dunn that appeared in Nature last year, is to analyze a large number of genes from a large number of animals. For this paper, the researchers looked at 1,487 genes, a 10-fold increase in the number of genes analyzed in previous studies. In all, the researchers logged 2.25 million processor hours on a supercomputer in California to obtain the results. Dunn called the effort the most computationally intensive phylogenetic analysis to date."

A color enhanced photo of the primitive flatworm Acoelomorpha

A Thick, Misty Haze of Organically Rich Compounds Filled the Atmosphere of a Young Earth and Contributed to the Development of Terrestrial Life Forms on the Surface of our Home Planet

The photochemistry of methane and carbon dioxide may have produced an organic haze layer on early Earth.. Credit: NASA

Anuradha K. Herath of PHYSORG.COM summarizes the view that: "Haze in the early Earth atmosphere could have played a crucial role in the origin of life. By forming a protective shield, the haze would have safeguarded organic substances from harmful ultraviolet (UV) radiation."

H. Langley DeWitt of the Department of Chemistry and Biochemistry at the University of Colorado at Boulder, adds his conjecture that "Knowing more about the atmospheric conditions right before life began to develop could give researchers clues to how exactly life developed.”

There was a global blanketing of organic haze across the young planet Earth according to a group of research scientists led by H. Langley DeWitt.

"Haze is produced when sunlight comes in contact with certain gases in the atmosphere," Herath explained. "The types of aerosols formed through this photochemical reaction depend on the specific composition of the atmosphere.

"The amount and the composition of the haze would determine whether it produced a warming or cooling effect for the planet. This new study shows that the amount of haze on early Earth was inadequate to have the type of cooling effect that scientists had previously predicted.The amount and the composition of the haze would determine whether it produced a warming or cooling effect for the planet. This new study shows that the amount of haze on early Earth was inadequate to have the type of cooling effect that scientists had previously predicted," concluded Herath.

Two other scientists; Armen Mulkidjanian of the University of Osnabrueck, Germany and Michael Galperin of the U.S. National Institutes of Health have advanced their view: "that life on Earth originated at photosynthetically-active porous structures, similar to deep-sea hydrothermal vents, made of zinc sulfide (more commonly known as phosphor). They argue that under the high pressure of a carbon-dioxide-dominated atmosphere, zinc sulfide structures could form on the surface of the first continents, where they had access to sunlight. Unlike many existing theories that suggest UV radiation was a hindrance to the development of life, Mulkidjanian and Galperin think it actually helped.

“The problem of the origin of life is such that you have to answer a set of different questions to explain how life has originated,” says lead author Mulkidjanian. “We just provide answers to the problem of energetics of the origin of life.”

Most scientists agree today that the atmosphere primarily originated from the accumulation of carbon dioxide mixed with smaller amounts of other gases. Living organisms originated by using some form of energy flow—solar radiation or chemical reactions to contribute to the development of life has also led some researchers to the conjecture that "zinc sulfide may have played a major role in the development of life" on Earth.."Its ability to store light makes zinc sulfide an important factor in the discussion on life’s origin." Mulkidjanian explains that, "once illuminated by UV light, zinc sulfide can efficiently reduce carbon dioxide, just as plants do."

Mulkidjanian and Galperin "suggest that life on Earth originated at photosynthetically-active porous structures, similar to deep-sea hydrothermal vents, made of zinc sulfide (more commonly known as phosphor). They argue that under the high pressure of a carbon-dioxide-dominated atmosphere, zinc sulfide structures could form on the surface of the first continents, where they had access to sunlight. Unlike many existing theories that suggest UV radiation was a hindrance to the development of life, Mulkidjanian and Galperin think it actually helped.

“The problem of the origin of life is such that you have to answer a set of different questions to explain how life has originated,” says lead author Mulkidjanian. “We just provide answers to the problem of energetics of the origin of life.”

"Included in these recent theories concerning the developments of terrestrial life is the proposal "that there was plate-tectonic activity in the first 500 million years of Earth's history," said geochemistry professor Mark Harrison, director of UCLA's Institute of Geophysics and Planetary Physics and co-author of the Nature paper. "We are reporting the first evidence of this phenomenon."

"Unlike the longstanding myth of a hellish, dry, desolate early Earth with no continents, it looks like as soon as the Earth formed, it fell into the same dynamic regime that continues today," Harrison said. "Plate tectonics was inevitable, life was inevitable. In the early Earth, there appear to have been oceans; there could have been life — completely contradictory to the cartoonish story we had been telling ourselves."

"We're revealing a new picture of what the early Earth might have looked like," said lead author Michelle Hopkins, a UCLA graduate student in Earth and space sciences. "In high school, we are taught to see the Earth as a red, hellish, molten-lava Earth. Now we're seeing a new picture, more like today, with continents, water, blue sky, blue ocean, much earlier than we thought."

"The research by Harrison, Hopkins and Craig Manning, a UCLA professor of geology and geochemistry, is based on their analysis of ancient mineral grains known as zircons found inside molten rocks, or magmas, from Western Australia that are about 3 billion years old. Zircons are heavy, durable minerals related to the synthetic cubic zirconium used for imitation diamonds and costume jewelry. The zircons studied in the Australian rocks are about twice the thickness of a human hair.

"... Analysis determined that some of the zircons found in the magmas were more than 4 billion years old. They were also found to have been formed in a region with heat flow far lower than the global average at that time.

"The global average heat flow in the Earth's first 500 million years was thought to be about 200 to 300 milliwatts per meter squared," Hopkins said. "Our zircons are indicating a heat flow of just 75 milliwatts per meter squared — the figure one would expect to find in subduction zones, where two plates converge, with one moving underneath the other."

"The data we are reporting are from zircons from between 4 billion and 4.2 billion years ago," Harrison said. "The evidence is indirect, but strong. We have assessed dozens of scenarios trying to imagine how to create magmas in a heat flow as low as we have found without plate tectonics, and nothing works; none of them explain the chemistry of the inclusions or the low melting temperature of the granites."

"Evidence for water on Earth during the planet's first 500 million years is now overwhelming, according to Harrison.

"You don't have plate tectonics on a dry planet," he said.

"Strong evidence for liquid water at or near the Earth's surface 4.3 billion years ago was presented by Harrison and colleagues in a Jan. 11, 2001, cover story in Nature.

"Five different lines of evidence now support that once radical hypothesis," Harrison said. "The inclusions we found tell us the zircons grew in water-saturated magmas. We now observe a surprisingly low geothermal gradient, a low rate at which temperature increases in the Earth. The only mechanism that we recognize that is consistent with everything we see is that the formation of these zircons was at a plate-tectonic boundary. In addition, the chemistry of the inclusions in the zircons is characteristic of the two kinds of magmas today that we see at place-tectonic boundaries."

"We developed the view that plate tectonics was impossible in the early Earth," Harrison added. "We have now made observations from the Hadean (the Earth's earliest geological eon) — these little grains contain a record about the conditions under which they formed — and the zircons are telling us that they formed in a region with anomalously low heat flow. Where in the modern Earth do you have heat flow that is one-third of the global average, which is what we found in the zircons? There is only one place where you have heat flow that low in which magmas are forming: convergent plate-tectonic boundaries."

"Three years ago, Harrison and his colleagues applied a technique to determine the temperature of ancient zircons.

"We discovered the temperature at which these zircons formed was constant and very low," Harrison said. "You can't make a magma at any lower temperature than what we're seeing in these zircons. You look at artists' conceptions of the early Earth, with flying objects from outer space making large craters; that should make zircons hundreds of degrees centigrade hotter than the ones we see. The only way you can make zircons at the low temperature we see is if the melt is water-saturated. There had to be abundant water. That's a big surprise because our longstanding conception of the early Earth is that it was dry."

"Scientists have looked to Titan, Saturn’s largest moon," Herath explained, "to try to better understand the organic haze that may have existed on early Earth. Titan has a thick atmosphere containing 95 percent nitrogen, three percent methane and two percent of hydrogen and other hydrocarbons, and an atmospheric pressure about 1.6 times that of Earth. Titan is also the only planetary body other than Earth with surface liquid (on Earth that surface liquid is water, while on Titan the surface liquid is ethane and methane.)

"In a 2006 NASA study, a group of researchers that included DeWitt replicated the atmospheres of Titan and early Earth. They then compared the aerosols produced in the laboratory to the haze observed in Titan’s atmosphere during NASA’s Cassini mission. The group concluded that the two atmospheres were similar.

"But there was one troubling result. An important distinction between the atmospheres of Titan and Earth is the carbon dioxide that is present in the Earth’s atmosphere. The laboratory results in the 2006 study suggested that the reaction of carbon dioxide and methane would produce more haze on early Earth than the amount found on Titan. That implies that the Earth would have been subjected to a large anti-greenhouse or cooling effect.

"The current study puts that concern to rest. DeWitt and her colleagues did additional laboratory experiments that expanded upon the 2006 study. They added hydrogen to the atmospheric composition and found that it reduced aerosol formation to the point where any potential anti-greenhouse effect would be negligible.

A colorized image of Titan’s haze taken during the Cassini mission. Credit: NASA/JPL/Space Science Institute

"DeWitt’s team also looked at how varying quantities of the three main substances—hydrogen, methane and carbon dioxide—may have affected the haze that formed on Earth billions of years ago.

“Many models calculate the amount of haze that would be present at the different ratios of these chemicals,” DeWitt explains. “However, the models don’t always include experimental data in their calculations and instead use assumptions about the chemistry.”

"The new study used a simplified version of an atmospheric model to examine two scenarios. One mixture contained high quantities of hydrogen and carbon dioxide with low amounts of methane. In the second simulation, the team analyzed the effects of hydrogen in a mixture that contained high amounts of methane. After the gas mixtures were exposed to UV radiation, the scientists measured the aerosols that were formed.

"Their findings showed that an increase in hydrogen levels reduced the haze formation rate. They also concluded that the amount of hydrogen present in the early Earth atmosphere most likely resulted in warmer surface temperatures.

“If an organic haze did form on early Earth, the consequences of its presence beg all sorts of interesting questions,” says co-author Christa Hasenkopf of the Cooperative Institute for Research in Environmental Sciences, also at the University of Colorado at Boulder.

"A question for astrobiologists is what role haze would have played in the formation of life. The scientists stated that the aerosols produced on early Earth provided a major source of organic substances to the Earth’s surface. Scientists think these organics played an important role in the origin of life on our planet. Understanding the characteristics of haze that make a planet’s surface ripe for organic material could be immensely helpful in the quest for life on other planetary bodies.

"Hasenkopf says some scientists believe that the early Earth atmosphere was “virtually oxygen-free when life first formed.” That allows astrobiologists to think more broadly about what types of environments on other planets could possibly support life.

“We only know of one place in the entire universe that life was able to initially form and develop, and that was on the early Earth,” says Hasenkopf. “The climactic conditions on early Earth provide clues to our own origins.”

"Scientists don’t know enough about our planet’s environment approximately four billion years ago to be able to precisely mimic the atmospheric conditions back then. The laboratory re-creation of early Earth therefore was based on many assumptions.

"The study model used simplified calculations for determining surface temperature, and the chemical reactions were based on shorter reaction times than what would have occurred under actual conditions. Additionally, the researchers only focused on three gases: methane, carbon dioxide and hydrogen. While these are believed to be the major constituents of the early Earth atmosphere, there could have been other components, such as sulfur dioxide, which were not taken into account in this study. Still, DeWitt says their study could improve the accuracy of models that predict chemical reactions in the atmosphere.

"Hasenkopf says the findings also can contribute to the understanding of the current effects of climate change.

"Some scientists believe that the early Earth atmosphere contained higher levels of carbon dioxide and methane than current atmospheric levels. Hasenkopf explains that the interaction between the gases that produce greenhouse warming and the haze that brings about the anti-greenhouse cooling is similar to the present-day emissions caused by human activity.

“On one hand, humans emit greenhouse gases, such as carbon dioxide, causing warming,” Hasenkopf says. “Yet humans also emit large amounts of particulate pollution, which may have a net cooling effect, similar to the early Earth haze.”

Recent Research in Humanity's Migration Out of Africa Took Place More Recently Than Previously Believed

Humans spread out of Africa later

Modern humans spread out of Africa 20,000 years later than previously thought, according to new genetic research just published. Detailed world map showing directions and times of major migration of modern humans. New research shows they spread out of Africa 20,000 years later than previously thought at around 55-60,000 years ago.

© Trends in Ecology & Evolution

Research scientists are constantly developing new approaches to developing innovative methods  to examine information obtained from mitochondrial DNA (mtDNA). Professor Chris Stringer has been studying the various methods scientists use to determine chronologies for important points in human evolutionary history.

"Mitochondria are the tiny structures in each human cell that produce the cell’s power. They contain their own DNA and this is inherited through the mother."

‘We tried alternative ways to date recent episodes in human evolution, such as our split from Neanderthals, and we found these events occurred more recently in time,’ says Prof Stringer.

It is now believed that modern humans and Neanderthals underwent a species separation approximately 300-400,000 years ago; this is much earlier than the previously accepted era 500-600,000 years ago.

It is believed that: "modern humans migrated out of Africa between 55-60,000 years ago rather than the previous dates of 70-80,000 years."

Researchers have also ascertained "more recent dates for other crucial events such as the age of our African ancestral mother, known as mitochondrial Eve, from who all recent humans (Homo sapiens) descended. She was found to have lived around 110-130,000 years ago, rather than previous estimates of 150,000-200,000 years ago.

‘The new dates are consistent with the most recent fossil and archaeological data for Neanderthal evolution, our exit from Africa and our arrival in Asia, Australia, Europe and the Americas,’ says Prof Stringer.

‘And they also cast doubt on ideas of an early exit from Africa towards China and Australia.’

Sources: PHYSORG.COM; Chris Stringer, Phillip Endicott, Simon Y.W. Ho, and Mait Metspalu's Evaluating the Mitochondrial Timescale of Human Evolution paper is published in the journal Trends in Ecology and Evolution; American Museum of Natural History (news : web)