Christian Science Monitor: The first experiment in “melting pot” politics in North America appears to have emerged nearly 1,000 years ago in the bottom lands of the Mississippi River near today’s St. Louis, according to archaeologists piecing together the story of the rise and fall of the native American urban complex known as Cahokia.

During its heyday, Cahokia’s population reached an estimated 20,000 people – a level the continent north of the Rio Grande wouldn’t see again until the eve of the American Revolution and the growth of New York and Philadelphia.

Cahokia’s ceremonial center, seven miles northeast of St. Louis’s Gateway Arch, boasted 120 earthen mounds, including a broad, tiered mound some 10 stories high. In East St. Louis, one of two major satellites hosts another 50 earthen mounds, as well as residences. St. Louis hosted another 26 mounds and associated dwellings.

These are three of the four largest native-American mound centers known, “all within spitting distance of one another,” says Thomas Emerson, Illinois State Archaeologist and a member of a team testing the melting-pot idea. “That’s some kind of large, integrated complex to some degree.”

Where did all those people come from? Archaeologists have been debating that question for years, Dr. Emerson says. Unfortunately, the locals left no written record of the complex’s history. Artifacts such as pottery, tools, or body ornaments give an ambiguous answer.

Artifacts from Cahokia have been found in other native-American centers from Arkansas and northern Louisiana to Oklahoma, Iowa, and Wisconsin, just as artifacts from these areas appear in digs at Cahokia.

“Archaeologists are always struggling with this: Are artifacts moving, or are people moving?” Emerson says.

Emerson and two colleagues at the University of Illinois at Urbana-Champaign tried to tackle the question using two radioactive forms of the element strontium found in human teeth. They discovered that throughout the 300 years that native Americans occupied Cahokia, the complex appeared to receive a steady stream of immigrants who stayed. [Continue reading…]

Music: Roberta Sá & Yamandu Costa — ‘Modinha’

Music: Roberta Sá and Trio Madeira Brasil — ‘Mandingo’

Music: Buika — ‘Por El Amor De Amar (Necesito Amor)’

Music: Mayra Andrade — ‘Dispidida’

Music: Buika — ‘No Habrá Nadie En El Mundo’

Music: René Aubry — ‘Salento’

Music: Mayra Andrade — ‘Tchapu na bandera’

Music: Dhafer Youssef — ‘In The Name Of Love’

Music: Dhafer Youssef — ‘Odd Elegy’

The beginning of everything — when our universe expanded faster than the speed of light

Space.com: Astronomers announced Monday (March 17) that they have discovered a telltale signature of gravitational waves in the cosmic microwave background radiation (CMB), the light left over from the universe’s birth 13.8 billion years ago.

The new results suggest that space-time really did expand at many times the speed of light in the first few tiny fractions of a second after the Big Bang, as predicted by the theory of cosmic inflation, researchers say.

That may seem impossible, since Albert Einstein’s theory of special relativity holds that nothing can travel faster than light. That rule, however, applies only to matter and information moving through space, not to the expansion of space-time itself. [Continue reading…]

Space.com: The new research also lends credence to the idea of a multiverse. This theory posits that, when the universe grew exponentially in the first tiny fraction of a second after the Big Bang, some parts of space-time expanded more quickly than others. This could have created “bubbles” of space-time that then developed into other universes. The known universe has its own laws of physics, while other universes could have different laws, according to the multiverse concept.

“It’s hard to build models of inflation that don’t lead to a multiverse,” Alan Guth, an MIT theoretical physicist unaffiliated with the new study, said during a news conference Monday. “It’s not impossible, so I think there’s still certainly research that needs to be done. But most models of inflation do lead to a multiverse, and evidence for inflation will be pushing us in the direction of taking [the idea of a] multiverse seriously.” [Continue reading…]

Click “Read more” link to see a “Cosmic Inflation” infographic.
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In unseen worlds, science invariably crosses paths with fantasy

Philip Ball writes: For centuries, scientists studied light to comprehend the visible world. Why are things colored? What is a rainbow? How do our eyes work? And what is light itself? These are questions that preoccupied scientists and philosophers since the time of Aristotle, including Roger Bacon, Isaac Newton, Michael Faraday, Thomas Young, and James Clerk Maxwell.

But in the late 19th century all that changed, and it was largely Maxwell’s doing. This was the period in which the whole focus of physics — then still emerging as a distinct scientific discipline — shifted from the visible to the invisible. Light itself was instrumental to that change. Not only were the components of light invisible “fields,” but light was revealed as merely a small slice of a rainbow extending far into the unseen.

Physics has never looked back. Today its theories and concepts are concerned largely with invisible entities: not only unseen force fields and insensible rays but particles too small to see even with the most advanced microscopes. We now know that our everyday perception grants us access to only a tiny fraction of reality. Telescopes responding to radio waves, infrared radiation, and X-rays have vastly expanded our view of the universe, while electron microscopes, X-ray beams, and other fine probes of nature’s granularity have unveiled the microworld hidden beyond our visual acuity. Theories at the speculative forefront of physics flesh out this unseen universe with parallel worlds and with mysterious entities named for their very invisibility: dark matter and dark energy.

This move beyond the visible has become a fundamental part of science’s narrative. But it’s a more complicated shift than we often appreciate. Making sense of what is unseen — of what lies “beyond the light” — has a much longer history in human experience. Before science had the means to explore that realm, we had to make do with stories that became enshrined in myth and folklore. Those stories aren’t banished as science advances; they are simply reinvented. Scientists working at the forefront of the invisible will always be confronted with gaps in knowledge, understanding, and experimental capability. In the face of those limits, they draw unconsciously on the imagery of the old stories. This is a necessary part of science, and these stories can sometimes suggest genuinely productive scientific ideas. But the danger is that we will start to believe them at face value, mistaking them for theories.

A backward glance at the history of the invisible shows how the narratives and tropes of myth and folklore can stimulate science, while showing that the truth will probably turn out to be far stranger and more unexpected than these old stories can accommodate. [Continue reading…]