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Odd properties of water and ice explained: Water exists as two different liquids

We normally consider liquid water as disordered with the molecules rearranging on a short time scale around some average structure. Now, however, scientists at Stockholm University have discovered two phases of the liquid with large differences in structure and density. The results are based on experimental studies using X-rays, which are now published in Proceedings of the National Academy of Science.

Pictured is an artist’s impression of the two forms of ultra-viscous liquid water with different density. On the background is depicted the x-ray speckle pattern taken from actual data of high-density amorphous ice, which is produced by pressurizing water at very low temperatures.

Most of us know that water is essential for our existence on planet Earth. It is less well-known that water has many strange or anomalous properties and behaves very differently from all other liquids. Some examples are the melting point, the density, the heat capacity, and all-in-all there are more than 70 properties of water that differ from most liquids. These anomalous properties of water are a prerequisite for life as we know it. Read more

Acidified ocean water widespread along North American West Coast

A three-year survey of the California Current System along the West Coast of the United States found persistent, highly acidified water throughout this ecologically critical nearshore habitat, with “hotspots” of pH measurements as low as any oceanic surface waters in the world.

Tidepool organisms are threatened by acidification.

The researchers say that conditions will continue to worsen because the atmospheric carbon dioxide primarily to blame for this increase in acidification has been rising substantially in recent years.

One piece of good news came out of the study, which was published this week in Scientific Reports. There are “refuges” of more moderate pH environments that could become havens for some marine organisms to escape more highly acidified waters, and which could be used as a resource for ecosystem management. Read more

Milk better than water to rehydrate kids, study finds

Active children need to be watered with milk. It’s a more effective way of countering dehydration than a sports drink or water itself, say researchers at McMaster University.

McMaster University graduate student Kim Volterman monitors research participant Paige Leonard’s heart rate in the climate chamber at the Children’s Exercise and Nutrition Centre of McMaster University and the McMaster Children’s Hospital.

That’s particularly important during hot summer weather, says Brian Timmons, research director of the Child Health and Exercise Medicine Program at McMaster and principal investigator of the study.

“Children become dehydrated during exercise, and it’s important they get enough fluids, particularly before going into a second round of a game. Milk is better than either a sports drink or water because it is a source of high quality protein, carbohydrates, calcium and electrolytes.” Read more

Water and Radiation on Saturn’s Moon Enceladus Can be Conditions for Life

Specialists of the University of Texas at San Antonio (USA) have found that microorganisms can live in water that has been exposed to radiation. Suitable conditions are on several celestial bodies, including Enceladus, the satellite of Saturn.

The source of radioactive radiation on Enceladus can be rocks that are close in composition to chondrites – the most common type of meteorites that contain uranium, potassium and thorium. And the existence of the oceans of water on Enceladus is very likely. Read more

Water balance creates a threshold in soil pH at the global scale

Soil pH regulates the capacity of soils to store and supply nutrients, and thus contributes substantially to controlling productivity in terrestrial ecosystems.

However, soil pH is not an independent regulator of soil fertility—rather, it is ultimately controlled by environmental forcing. In particular, small changes in water balance cause a steep transition from alkaline to acid soils across natural climate gradients.

Although the processes governing this threshold in soil pH are well understood, the threshold has not been quantified at the global scale, where the influence of climate may be confounded by the effects of topography and mineralogy. Here we evaluate the global relationship between water balance and soil pH by extracting a spatially random sample (n = 20,000) from an extensive compilation of 60,291 soil pH measurements. Read more