Water falls all over the planet, but when it passes through soil and rocks it slowly dissolves bits of minerals, including sodium chloride (salt). This means rivers and lakes have tiny fragments of salt in them, which — little by little — are carried into the sea.
Why is the sea salty and rivers and lakes aren't? - The Boston Globe - 1 views
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Rivers and lakes are replenished with fresh rainwater, but oceans are a sort of dumping ground where water with accumulated salt keeps adding to the salinity. There are also vents and volcanoes under the ocean that increase the amount of minerals, especially salt.
Sleep Facts: 20 Facts about Sleep you didn't know ←FACTSlides→ - 1 views
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Humans spend a third of their life sleeping. That's about 25 years.
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The record for the longest period without sleep is 11 days.
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Sleeping less than 7 hours each night reduces your life expectancy.
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Knowledge To Kids: Why Is The Sea Water Salty? - 1 views
Why is the ocean salty, but rivers flowing into it are not? - 1 views
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In the beginning, the primeval seas were probably only slightly salty. But over time, as rain fell to the Earth and ran over the land, breaking up rocks and transporting their minerals to the ocean, the ocean has become saltier.
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Rain replenishes freshwater in rivers and streams, so they don’t taste salty. However, the water in the ocean collects all of the salt and minerals from all of the rivers that flow into i
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It is estimated that the rivers and streams flowing from the United States alone discharge 225 million tons of dissolved solids and 513 million tons of suspended sediment annually to the ocean. Throughout the world, rivers carry an estimated four billion tons of dissolved salts to the ocean annually.
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What do Dolphins Eat? - Dolphin Facts and Information - 0 views
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While some dolphins eat fishes like herring, cod or mackerel, some others eat squids.
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Even more, large dolphins like the killer whales, eat some other marine mammals like seals or sea lions and sometime even turtles.
Neptune -- Britannica School - 0 views
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The planet that Voyager uncovered is a stormy, windswept world with a vivid blue hue. Its highly active atmosphere is surprising, since it receives so little sunlight to power its weather systems. Like the other giant outer planets, Neptune has no solid surface. It also has a system of rings and more than a dozen moons.
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Neptune is the smallest of the four giant outer planets. The diameter at its equator is about 30,775 miles (49,528 kilometers), as measured at a level of the atmosphere where the pressure is 1 bar (the pressure at sea level on Earth). This makes it slightly smaller than Uranus but nearly four times as big as Earth. Neptune’s mass is about 1.2 times greater than Uranus’, however, and more than 17 times greater than Earth’s. It is the third most massive planet in the solar system, after Jupiter and Saturn. Like the other outer planets, Neptune has a low density—only about 1.6 times the density of water. However, it is the densest of the four, being roughly 25 percent denser than Uranus.
Dolphin - Wikipedia, the free encyclopedia - 0 views
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Dolphins are cetacean mammals closely related to whales and porpoises. There are almost forty species of dolphin in 17 genera. They vary in size from 1.2 m (4 ft) and 40 kg (90 lb) (Maui's dolphin), up to 9.5 m (30 ft) and 10 tonnes (9.8 long tons; 11 short tons) (the orca or killer whale). They are found worldwide, mostly in the shallower seas of the continental shelves and are carnivores, eating mostly fish and squid. The family Delphinidae, the largest in the order Cetacea, evolved relatively recently, about ten million years ago during the Miocene.
Uranus -- Britannica School - 0 views
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Uranus is the third largest planet in the solar system, after Jupiter and Saturn. Uranus is about four times bigger than Earth. Its diameter at the equator is about 31,763 miles (51,118 kilometers), as measured at the level of the atmosphere where the pressure is the same as at sea level on Earth. The planet is slightly larger than Neptune, but Neptune is about 1.2 times more massive. Uranus’ density is quite low—only about 1.3 times that of water, compared with 1.6 for Neptune and 5.5 for rocky Earth.
Why is the Ocean Salty? - 1 views
Why is the sea salty? - 1 views
Christopher Columbus Discovers America, 1492 - 0 views
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Columbus led his three ships - the Nina, the Pinta and the Santa Maria - out of the Spanish port of Palos on August 3, 1492. His objective was to sail west until
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he reached Asia (the Indies) where the riches of gold, pearls and spice awaited. His first stop was the Canary Islands where the lack of wind left his expedition becalmed until September 6.
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Why are Oceans Salty? - EnchantedLearning.com - 0 views
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As water flows in rivers, it picks up small amounts of mineral salts from the rocks and soil of the river beds.
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but the salt remains dissolved in the ocean - it does not evaporate. So the remaining water gets saltier and saltier as time passes.
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This very-slightly salty water flows into the oceans and seas. The water in the oceans only leaves by evaporating (and the freezing of polar ice),
How birds fly | Sciencelearn Hub - 0 views
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Birds have many physical features, besides wings, that work together to enable them to fly. They need lightweight, streamlined, rigid structures for flight. The four forces of flight – weight, lift, drag and thrust – affect the flight of birds.
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Flying birds have: lightweight, smooth feathers – this reduces the forces of weight and drag a beak, instead of heavy, bony jaws and teeth – this reduces the force of weight an enlarged breastbone called a sternum for flight muscle attachment – this helps with the force of thrust light bones – a bird’s bones are basically hollow with air sacs and thin, tiny cross pieces to make bones stronger – this reduces the force of weight a rigid skeleton to provide firm attachments for powerful flight muscles – this helps with the force of thrust a streamlined body – this helps reduce the force of drag wings – these enable the force of lift.
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WingsThe shape of a bird’s wing is important for producing lift. The increased speed over a curved, larger wing area creates a longer path of air. This means the air is moving more quickly over the top surface of the wing, reducing air pressure on the top of the wing and creating lift. Also, the angle of the wing (tilted) deflects air downwards, causing a reaction force in the opposite direction and creating lift.Larger wings produce greater lift than smaller wings. So smaller-winged birds (and planes) need to fly faster to maintain the same lift as those with larger wings.Wing loading tells you how fast a bird or plane must fly to be able to maintain lift: wing loading = weight/wing area (kilograms per square metre).A smaller wing loading number means the bird/plane can fly more slowly while still maintaining lift and is more manoeuvrable.
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The Mariners' Museum | EXPLORATION through the AGES - 0 views
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d. He had brothers, Thorvald and Thorstein, and a half-sister, Freydis. In the year 999 BCE, Ericsson sailed to Norway to visit King Olaf Trygvson. On his way the ship was blown off course and he landed on one of the Hebrides islands. Continuing poor weather made it impossible for him to leave so he spent the summer on the island.
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. She gave birth to his son and as his departure date drew near, she asked that he take her with him. He refused, citing her family connections. Thorgunna had a reputation for being able to predict the future, and vowed that even though Leif was leaving them, one day she and their son would journey to find him and the experience would not be a good one.
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, while other sources claim that when the boy was old enough to travel, he found Leif.
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