Robotics

An army of microrobots can wipe out dental plaque

visit to the dentist typically involves time-consuming and sometimes unpleasant scraping with mechanical tools to remove plaque from teeth. What if, instead, a dentist could deploy a small army of tiny robots to precisely ...

Other

NOAA satellites helped rescue 340 people in 2018

The pilot of the rowboat Alba had a noble goal – to raise awareness and funds for the Scottish Association for Mental Health. And he was going to row 3,400 nautical miles, from Norfolk, Va., to his home in Scotland, to ...

Robotics

Researchers create 3-D-printed soft mesh robots

Researchers at North Carolina State University have created 3-D-printed flexible mesh structures that can be controlled with applied magnetic fields while floating on water. The structures can grab small objects and carry ...

Energy & Green Tech

Low-cost catalyst boosts hydrogen production from water

A future powered by carbon-free fuel depends on our ability to harness and store energy from renewable but intermittent sources, such as solar and wind. Now, a new catalyst developed at University of Toronto Engineering gives ...

Engineering

Sun-soaking device turns water into superheated steam

MIT engineers have built a device that soaks up enough heat from the sun to boil water and produce "superheated" steam hotter than 100 degrees Celsius, without any expensive optics.

Engineering

Geckos filmed to find out how they walk on water

Anyone who's seen a gecko will likely know they can climb walls. But these common lizards can also run across water nearly as fast as they can move on solid ground. Yet while we know how geckos scale smooth vertical surfaces ...

Robotics

Aquatic animals that jump out of water inspire leaping robots

Ever watch aquatic animals jump out of the water and wonder how they manage to do it in such a streamlined and graceful way? A group of researchers who specialize in water entry and exit in nature had the same question and ...

Energy & Green Tech

Water out of thin air: California couple's device wins $1.5M

It started out modestly enough: David Hertz, having learned that under the right conditions you really can make your own water out of thin air, put a little contraption on the roof of his office and began cranking out free ...

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Water

Water is a ubiquitous chemical substance, composed of hydrogen and oxygen, that is essential for the survival of many known forms of life. In typical usage, water refers only to its liquid form or state, but the substance also has a solid state, ice, and a gaseous state, water vapor or steam. Water covers 71% of the Earth's surface. On Earth, it is found mostly in oceans and other large water bodies, with 1.6% of water below ground in aquifers and 0.001% in the air as vapor, clouds (formed of solid and liquid water particles suspended in air), and precipitation. Saltwater oceans hold 97% of surface water, glaciers and polar ice caps 2.4%, and other land surface water such as rivers, lakes and ponds 0.6%. A very small amount of the Earth's water is contained within biological bodies and manufactured products. Other water is trapped in ice caps, glaciers, aquifers, or in lakes, sometimes providing fresh water for life on land.

Water moves continually through a cycle of evaporation or transpiration (evapotranspiration), precipitation, and runoff, usually reaching the sea. Winds carry water vapor over land at the same rate as runoff into the sea. Over land, evaporation and transpiration contribute to the precipitation over land.

Clean, fresh drinking water is essential to human and other lifeforms. Access to safe drinking water has improved steadily and substantially over the last decades in almost every part of the world. There is a clear correlation between access to safe water and GDP per capita. However, some observers have estimated that by 2025 more than half of the world population will be facing water-based vulnerability. Water plays an important role in the world economy, as it functions as a solvent for a wide variety of chemical substances and facilitates industrial cooling and transportation. Approximately 70 percent of freshwater is consumed by agriculture.

This text uses material from Wikipedia, licensed under CC BY-SA