Tag Archives: atmospheric pressure

Martian salts must touch ice to make liquid water, study shows

ANN ARBOR — In chambers that mimic Mars’ conditions, University of Michigan researchers have shown how small amounts of liquid water could form on the planet despite its below-freezing temperatures.

Liquid water is an essential ingredient for life as we know it. Mars is one of the very few places in the solar system where scientists have seen promising signs of it – in gullies down crater rims, in instrument readings, and in Phoenix spacecraft self portraits that appeared to show wet beads on the lander’s leg several years ago. (more…)

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Fossil Raindrop Impressions Imply Greenhouse Gases Loaded Early Atmosphere

In ancient Earth history, the sun burned as much as 30 percent dimmer than it does now. Theoretically that should have encased the planet in ice, but there is geologic evidence for rivers and ocean sediments between 2 billion and 4 billion years ago.

Scientists have speculated that temperatures warm enough to maintain liquid water were the result of a much thicker atmosphere, high concentrations of greenhouse gases or a combination of the two. (more…)

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Disappearing and Reappearing Superconductivity Surprises Scientists

Washington, D.C. — Superconductivity is a rare physical state in which matter is able to conduct electricity—maintain a flow of electrons—without any resistance. This phenomenon can only be found in certain materials at low temperatures, or can be induced under chemical and high external pressure conditions. Research to create superconductors at higher temperatures has been ongoing for two decades with the promise of significant impact on electrical transmission. New work from a team including Carnegie’s Xiao-Jia Chen and Ho-kwang “Dave” Mao demonstrates unexpected superconductivity in a type of compounds called iron selenium chalcogenides. Their work is published online by Nature on February 22. (more…)

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Russian River Water Unexpected Culprit Behind Arctic Freshening

A hemispherewide phenomenon – and not just regional forces – has caused record-breaking amounts of freshwater to accumulate in the Arctic’s Beaufort Sea.

Frigid freshwater flowing into the Arctic Ocean from three of Russia’s mighty rivers was diverted hundreds of miles to a completely different part of the ocean in response to a decades-long shift in atmospheric pressure associated with the phenomenon called the Arctic Oscillation, according to findings published in the Jan. 5 issue of Nature. (more…)

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Searching for the “Perfect Glass”

Washington, D.C.— Glasses differ from crystals. Crystals are organized in repeating patterns that extend in every direction. Glasses lack this strict organization, but do sometimes demonstrate order among neighboring atoms. New research from Carnegie’s Geophysical Laboratory reveals the possibility of creating a metallic glass that is organized on a larger scale. Their results are published June 17 in Science.

Scientists have discovered glasses that demonstrate order among the nearest neighboring atoms, called short-range order, and a slightly wider range of atoms, called medium-range order. Most research about finding or creating a glass with a long-range, nearly crystalline, level of order—referred to as the perfect glass state—has been conducted on ice and the minerals silica and zeolite. But no research into long-range order glass has been successful until now. (more…)

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Mysteries of Unpredictable Tsunami Waves

One of the most terrible consequences of offshore quakes is giant tsunami waves, sweeping everything on their way. Until now, scientists cannot answer a simple question: why in some cases they happen, and in others they do not? If it was established, then a tragedy like the one that has recently occurred in Indonesia could have been avoided.

An earthquake measuring 7.5 points, which occurred late on Monday, October 25 in Indonesia, caused a tsunami, which affected Mentawai islands in the western part of the country. Interestingly, the epicenter of the aftershocks of this earthquake was located 78 km west of the South Island Pagai of the Mentawai archipelago, at a depth of 20 km below the bottom of the Pacific Ocean. Apparently, this is why the first few minutes after the earthquake the Indonesian government reported the tsunami threat, but later canceled the alert. (more…)

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Roller Coaster Superconductivity Discovered

Washington, D.C.— Superconductors are more than 150 times more efficient at carrying electricity than copper wires. However, to attain the superconducting state, these materials have to be cooled below an extremely low, so-called transition temperature, at which point normal electrical resistance disappears. Developing superconductors with higher transition temperatures is one of physics’ greatest quests.

(more…)

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