Seawater

Seawater, or salt water, is water from a sea or ocean. On average, seawater in the world's oceans has a salinity of about 3.5% (35 g/L, or 599 mM). This means that every kilogram (roughly one litre by volume) of seawater has approximately 35 grams (1.2 oz) of dissolved salts (predominantly sodium (Na+
) and chloride (Cl−
) ions). Average density at the surface is 1.025 kg/l. Seawater is denser than both fresh water and pure water (density 1.0 kg/l at 4 °C (39 °F)) because the dissolved salts increase the mass by a larger proportion than the volume. The freezing point of seawater decreases as salt concentration increases. At typical salinity, it freezes at about −2 °C (28 °F). The coldest seawater ever recorded (in a liquid state) was in 2010, in a stream under an Antarctic glacier, and measured −2.6 °C (27.3 °F). Seawater pH is typically limited to a range between 7.5 and 8.4. However, there is no universally accepted reference pH-scale for seawater and the difference between measurements based on different reference scales may be up to 0.14 units.

Water

Water (chemical formula: H₂O) is a transparent fluid which forms the world's streams, lakes, oceans and rain, and is the major constituent of the fluids of organisms. As a chemical compound, a water molecule contains one oxygen and two hydrogen atoms that are connected by covalent bonds. Water is a liquid at standard ambient temperature and pressure, but it often co-exists on Earth with its solid state, ice; and gaseous state, steam (water vapor). It also exists as snow, fog, dew and cloud.

Water covers 71% of the Earth's surface. It is vital for all known forms of life. On Earth, 96.5% of the planet's crust water is found in seas and oceans, 1.7% in groundwater, 1.7% in glaciers and the ice caps of Antarctica and Greenland, a small fraction in other large water bodies, and 0.001% in the air as vapor, clouds (formed of ice and liquid water suspended in air), and precipitation. Only 2.5% of this water is freshwater, and 98.8% of that water is in ice (excepting ice in clouds) and groundwater. Less than 0.3% of all freshwater is in rivers, lakes, and the atmosphere, and an even smaller amount of the Earth's freshwater (0.003%) is contained within biological bodies and manufactured products. A greater quantity of water is found in the earth's interior.

Sea (astronomy)

The Sea or the Water is an area of the sky in which many water-related, and few land-related, constellations occur. This may be because the Sun passed through this part of the sky during the rainy season.

Most of these constellations are named by Ptolemy:

Sometimes included are the ship Argo and Crater the Water Cup.

Some water-themed constellations are newer, so are not in this region. They include Hydrus, the lesser water snake; Volans, the flying fish; and Dorado, the swordfish.

See also

References

Water (Elitsa & Stoyan song)

"Water" (Bulgarian script: Вода) was the Bulgarian entry in the Eurovision Song Contest 2007, performed in Bulgarian by Elitsa Todorova & Stoyan Yankoulov. This was the first occasion on which the Bulgarian language was used on the Eurovision stage, previous Bulgarian entries being performed in English. Originally titled "Voda", the song had its title translated to English for the Contest.

The song is an up-tempo number with techno influences, as well as a jaw harp and traditional percussion. Todorova sings folk-inspired lyrics dealing with a young girl meeting a young boy riding a horse.

The performance in the semi-final featured the duo wearing what looked like armour, while they were wearing more mainstream clothes in the final. The performances were also notable for the high-energy percussion performances of both musicians.

As Bulgaria had not finished the previous Contest in the top ten, the song was performed in the semi-final. Here, it was performed first (preceding Israel's Teapacks with "Push The Button"). At the close of voting, it had received 146 points, placing 6th in a field of 28 and qualifying Bulgaria for its first final.

Collins-class submarine replacement project

Identified as the most expensive defence procurement project to date in Australian history, the Collins-class replacement will provide Australia with a submarine capability deep into the twenty-first century. With the Royal Australian Navy's (RAN's) Collins-class submarines scheduled to begin leaving service from 2025 onwards, plans to replace them began in 2007 with the commencement of the defence acquisition project SEA 1000, also referred to as the Future Submarine Programme. Australia's unique operating environment (including significant variations in ocean climate and conditions) and rejection of nuclear propulsion had previously driven it to operate in the Collins-class the world's largest diesel-electric submarines, capable of transiting the long distances from HMAS Stirling to their deployment areas.

In the early phases of the replacement project, four design options were identified: purchase a Military-Off-The-Shelf (MOTS) design, modify a MOTS design for Australian conditions, design an evolution of the Collins-class, or create a new design. Nuclear propulsion has been ruled out due to the lack of an indigenous nuclear industry in Australia and public opposition to nuclear technology.