Category Archives: Science

A Prime Seat to a Once-in-a-Lifetime Spectacle

Hosted by world-renowned astrophotographer Adam Block at the UA’s Mount Lemmon SkyCenter, a group of sky and astronomy enthusiasts watched Venus cross the sun from the highest vantage point in Southern Arizona.

On Nov. 24, 1639, in the tiny village of Much Hoole not far from Liverpool, England, a poor farmer’s son and self-taught astronomer affixed a sheet of paper in front of a makeshift telescope pointed at the sun and waited.

Thirty-five minutes before sunset, a dark, round spot appeared right next to the bright disc that was the sun’s face projected on the paper, and made Jeremiah Horrocks, only 20 years old at the time, the first known human to predict, observe and record a transit – the passage of a planet across the sun as seen from Earth.

Almost 373 years later, a group of sky enthusiasts is gathered beneath the dome of one of the University of Arizona’s observatories on Mount Lemmon just north of Tucson, Ariz. (more…)

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A New Tool to Attack the Mysteries of High-Temperature Superconductivity

Berkeley Lab researchers use an ultrafast laser to better understand high-temperature superconductors

Superconductivity, in which electric current flows without resistance, promises huge energy savings – from low-voltage electric grids with no transmission losses, superefficient motors and generators, and myriad other schemes. But such everyday applications still lie in the future, because conventional superconductivity in metals can’t do the job.

Although they play important roles in science, industry, and medicine, conventional superconductors must be maintained at temperatures a few degrees above absolute zero, which is tricky and expensive. Wider uses will depend on higher-temperature superconductors that can function well above absolute zero. Yet known high-temperature (high-Tc) superconductors are complex materials whose electronic structures, despite decades of work, are still far from clear. (more…)

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How Ion Bombardment Reshapes Metal Surfaces

Ion bombardment of metal surfaces is an important, but poorly understood, nanomanufacturing technique. New research using sophisticated supercomputer simulations has shown what goes on in trillionths of a second. The advance could lead to better ways to predict the phenomenon and more uses of the technique to make new nanoscale products.

PROVIDENCE, R.I. [Brown University] — To modify a metal surface at the scale of atoms and molecules — for instance to refine the wiring in computer chips or the reflective silver in optical components — manufacturers shower it with ions. While the process may seem high-tech and precise, the technique has been limited by the lack of understanding of the underlying physics. In a new study, Brown University engineers modeled noble gas ion bombardments with unprecedented richness, providing long-sought insights into how it works. (more…)

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Ceramics Tell the Story of an Ancient Southwest Migration

Another look at a nearly 80-year-old pottery collection at the Arizona State Museum is yielding new information about migrants who abandoned the Four Corners region.

Approximately eight centuries ago, people living along the Colorado Plateau in what is now the Four Corners area faced a crisis. Environmental changes that devastated their agricultural practices and likely aggravated social unrest forced significant numbers of these people to move away. (more…)

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Climate Change Led to Collapse of Ancient Indus Civilization, Study Finds

A new study combining the latest archaeological evidence with state-of-the-art geoscience technologies provides evidence that climate change was a key ingredient in the collapse of the great Indus or Harappan Civilization almost 4000 years ago. The study also resolves a long-standing debate over the source and fate of the Sarasvati, the sacred river of Hindu mythology.

Once extending more than 1 million square kilometers across the plains of the Indus River from the Arabian Sea to the Ganges, over what is now Pakistan, northwest India and eastern Afghanistan, the Indus civilization was the largest—but least known—of the first great urban cultures that also included Egypt and Mesopotamia. Like their contemporaries, the Harappans, named for one of their largest cities, lived next to rivers owing their livelihoods to the fertility of annually watered lands. (more…)

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