Found: Bizarre form of water
2004-04-22 11:38
Stuttgart - A strange form of water has been discovered on frozen rocks, possibly explaining why glaciers slip down mountainsides and offering a solution to the problem of ice forming on aircraft wings, German scientists said on Wednesday.
High-density water, the bizarre new form of one of the commonest compounds on the planet, adds to the mysteries surrounding H2O.
Normal water achieves maximum density at four degrees Celsius and becomes less dense when it turns to ice. This is why frozen bottles and pipes containing water burst, and scientists prefer to describe ice as low-density water.
In an ordinary cup of water, the molecules are continually rearranging into sections of high- and low-density water. But scientists were not expecting to discover the high-density form below zero Celsius. But they did, as a thin film on frozen rocks.
Ice began to melt at minus 17 degrees in contact with silicium dioxide, one of the commonest components of the earth's crust.
The results of the experiments, which began in a walk-in refrigerator in the southern German city of Stuttgart, are shortly to appear in the journal Physical Review Letters under the title "Interfacial melting of ice in contact with silicium dioxide (SiO2)".
Announcing the findings, Germany's Max Planck Institute said the discovery was confirmed in experiments using X-rays at the European Synchrotron Radiation Facility (ESRF) in Grenoble, France. The water has a mass of 1.2 grams per millilitre.
The metric system is based on the assumption a millilitre of pure water has a mass of exactly one gram. The discovery by the Max Planck Institute for Metals Research could explain why glaciers move, why permafrost slips and possibly how cars lose traction on icy roads. - Sapa-dpa
- SAPA