Theme of the month

hi everybody, is the month of June and who say June say the beginin of the summer, vacation season, sun, that's why I have chosen as the theme of the month the beach, so you gonna find all articles which are related to that theme hope you will enjoy it and don't forget to leave a comment

Sand

Sand is a naturally occurring granular material composed of finely divided rock and mineral particles.
As the term is used by geologists, sand particles range in diameter from 0.0625 (or 1⁄16 mm) to 2 millimeters. An individual particle in this range size is termed a sand grain. The next smaller size class in geology is silt: particles smaller than 0.0625 mm down to 0.004 mm in diameter. The next larger size class above sand is gravel, with particles ranging from 2 mm up to 64 mm (see particle size for standards in use). Sand feels gritty when rubbed between the fingers (silt, by comparison, feels like flour).
ISO 14688 grades sands as fine, medium and coarse with ranges 0.063 mm to 0.2 mm to 0.63 mm to 2.0 mm. In USA, sand is commonly divided into five sub-categories based on size: very fine sand (1/16 - 1/8 mm diameter), fine sand (1/8 mm - 1/4 mm), medium sand (1/4 mm - 1/2 mm), coarse sand (1/2 mm - 1 mm), and very coarse sand (1 mm - 2 mm). These sizes are based on the Φ sediment size scale, where size in Φ = -log base 2 of size in mm. On this scale, for sand the value of Φ varies from -1 to +4, with the divisions between sub-categories at whole numbers.
·
Constituents of Sand
he most common constituent of sand, in inland continental settings and non-tropical coastal settings, is silica (silicon dioxide, or SiO2), usually in the form of quartz, which, because of its chemical inertness and considerable hardness, is resistant to weathering.
The composition of sand is highly variable, depending on the local rock sources and conditions. The bright white sands found in tropical and subtropical coastal settings are eroded limestone and may contain coral and shell fragments in addition to other organic or organically derived fragmental material.[1] The gypsum sand dunes of the White Sands National Monument in New Mexico are famous for their bright, white color. Arkose is a sand or sandstone with considerable feldspar content, derived from the weathering and erosion of a (usually nearby) granite. Some sands contain magnetite, chlorite, glauconite or gypsum. Sands rich in magnetite are dark to black in color, as are sands derived from volcanic basalts and obsidian. Chlorite-glauconite bearing sands are typically green in color, as are sands derived from basalt (lava) with a high olivine content. Many sands, especially those found extensively in Southern Europe, have iron impurities within the quartz crystals of the sand, giving a deep yellow colour. Sand deposits in some areas contain garnets and other resistant minerals, including some small gemstones.
Sand is transported by wind and water and deposited in the form of beaches, dunes, sand spits, sand bars and related features.
Study of Sand
Study of individual grains can reveal much historical information as to the origin and kind of transport of the grain. Quartz sand that is recently weathered from granite or gneiss quartz crystals will be angular. It is called sharp sand in the building trade where it is preferred for concrete, and in gardening where it is used as a soil amendment to loosen clay soils. Sand that is transported long distances by water or wind will be rounded, with characteristic abrasion patterns on the grain surface. Desert sand is typically rounded.
People who collect sand as a hobby are known as arenophiles or psammophiles.
Uses of Sand
.
Sand is often a principal component of concrete.
Molding sand, also known as foundry sand, is moistened or oiled and then shaped into molds for sand casting. This type of sand must be able to withstand high temperatures and pressure, allow gases to escape, have a uniform, small grain size and be non-reactive with metals.
It is the principal component in glass production.
Graded sand is used as an abrasive in sandblasting and is also used in media filters for filtering water.
Brick manufacturing plants use sand as an additive with a mixture of clay and other materials for manufacturing bricks.
Sand is sometimes mixed with paint to create a textured finish for walls and ceilings or a non-slip floor surface.
Sandy soils are ideal for certain crops such as watermelons, peaches, and peanuts and are often preferred for intensive dairy farming because of their excellent drainage characteristics.
Sand is used in landscaping, it is added to make small hills and slopes (for example, constructing golf courses).
Beach nourishment - transportation to popular beaches where seasonal tides or artificial changes to the shoreline cause the original sand to flow out to sea.[2]
Sandbags are used for protection against floods and gun fire. They can be easily transported when empty, then filled with local sand.
Sand castle building is a popular activity. There are competitive sand castle building competitions (See sand art and play).
Sand animation is a type of performance art and a technique for creating animated films.
Aquaria are often lined with sand instead of gravel. This is a low cost alternative which some believe is better than gravel.
Railroads use sand to improve the traction of wheels on the rails.
Weights can use sand in pulley and gear systems as weights.

sunrise

Reportage realised by me and sanaa sallou about the group sunrise (group of ballet and coregraphie)

watch

The Sea Spirit by Lucy Maud Montgomery (poem)

I smile o'er the wrinkled blue­
Lo! the sea is fair,
Smooth as the flow of a maiden's hair;
And the welkin's light shines through
Into mid-sea caverns of beryl hue,
And the little waves laugh and the mermaids sing,
And the sea is a beautiful, sinuous thing!

I scowl in sullen guise­
The sea grows dark and dun,
The swift clouds hide the sun
But not the bale-light in my eyes,
And the frightened wind as it flies
Ruffles the billows with stormy wing,
And the sea is a terrible, treacherous thing!

When moonlight glimmers dim
I pass in the path of the mist,
Like a pale spirit by spirits kissed.
At dawn I chant my own weird hymn,
And I dabble my hair in the sunset's rim,
And I call to the dwellers along the shore
With a voice of gramarye evermore.

And if one for love of me
Gives to my call an ear,
I will woo him and hold him dear,
And teach him the way of the sea,
And my glamor shall ever over him be;
Though he wander afar in the cities of men
He will come at last to my arms again.

animal of the month: dolphin

Did you know that ...
Unlike any other mammal, dolphin babies are born tail first.
Dolphins have very little sense of smell.
A mother dolphin will stay with a calf for two to three years.
Dolphins, like cows, have two stomachs — one for storing food and one for digesting it.
Some dolphins have been known to dive as deep as 1,000 feet.
A dolphin's dorsal fin is as distinctive as a person's face.
Some dolphin species can swim up to 25 miles an hour for long periods, more than three times faster than the best human swimmers.
In the wild, dolphins can live to be 50 years old, although the average age is 17 years.
Some dolphins can hold their breath for as long as 30 minutes, while others have to breathe every 20 seconds.
Bonds form between individual dolphins that may last a lifetime. They've been observed physically supporting sick or dying pod members.
Dolphins can be quite aggressive and even brutal. Dominant members of a pod have been known to abuse weaker members.
Thanks to a very sensitive retina that efficiently gathers light, a dolphin can see as well beneath the water as above it.
A dolphin's brain, in relation to the size of its body, is larger than the brains of chimpanzees and great apes.
An adult dolphin may consume 30 pounds of fish or more in a single day.
Dolphins swallow fish whole, despite the 100 teeth in their mouths. The teeth are used to grasp prey.
Dolphins can jump as high as 20 feet out of the water.
The largest member of the dolphin family is the killer whale, which can grow to 30 feet long.
A dolphin's skin is extremely delicate and easily injured by rough surfaces — much like human skin.
The largest of the freshwater dolphins is the boto, found in the Amazon River. It can grow 10 feet long.

What makes dolphins so smart?
Well, their brains, of course. Dolphins have large brains for their bodies — in fact, a bottlenose dolphin is second only to humans in the ratio of brain size to body size. Researchers have also pointed to the parallels in the organization of dolphin and primate brains as more evidence of high intelligence in dolphins. Some have gone so far as to suggest that dolphins actually have a language that humans simply cannot comprehend.
But others say that in our enthusiasm to anthropomorphize dolphins, we give them powers they just don't possess. A closer look suggests that much of the dolphin's large brain is taken up with echolocation and handling acoustical information — processes at which they excel. But dolphins tend to rank at about the level of elephants in "intelligence" tests and haven't shown any unusual talent at problem solving.
They are excellent mimics of sounds and clearly communicate with one another, but does that mean they "talk?" No one less than Aristotle once wrote, "The voice of the dolphin in the air is like that of the human in that they can pronounce vowels and combinations of vowels, but have difficulties with the consonants." But a more scientific analysis of dolphin sounds suggests that for all their communication skills, dolphins lack the repertoire to have anything approaching language as we know it.
So what have researchers learned about dolphin intelligence?Dolphin researcher Pieter Arend Folkens tells this story: "Since trash can be dangerous to dolphins if ingested, some of the animals at Marine World Africa USA were trained to retrieve the trash and return it to the trainer for a reinforcement reward.
"A trainer would come out onto the floating stage and a dolphin would perform a tail stand with a piece of trash in its mouth. The trainer would then reward the dolphin with a bit of fish.
"One day the lead trainer went through the routine only to notice that the dolphin kept coming back with a piece of trash even though the tank appeared clean. The trainer asked a colleague to go below to the engineer's port to observe what the dolphin was doing when a trainer came out on the float. The trainer came out on the float and sure enough, the dolphin quickly showed up with a piece of trash and got his reward.
"The scam was revealed! This dolphin had established a savings account of sorts. He collected all the trash and stuffed it in a bag wedged in a corner of the tank near the intake of the filtering system. In there was paper, rope, and all sorts of trash. The amazing thing is that when he went to the bank he did not simply take a piece, rather he would tear a bit off to maximize the return.
"This behavior is particularly interesting because it shows that the dolphin had a sense of the future and delayed gratification. He had enough presence to realize that a big piece of trash got the same reward as a small piece, so why not deliver only small pieces to keep the extra food coming? He in effect had trained the humans."
How complex is dolphin communication?In a noted experiment Dr. Javis Bastian found that dolphins could communicate about abstract ideas. Two dolphins in captivity, Buzz and Doris, were trained to push different switches to earn a fish. When a light came on and stayed on, they were supposed to push the right switch. When it blinked on and off, they were to push the left switch. No problem. But then the test became more complicated. They were taught to follow a sequence — Doris had to wait for Buzz to press the signal first. Then they were separated so they could only hear each other. Finally, Buzz was blocked from seeing the light.
When the light came on under those conditions and stayed on, Doris waited for Buzz to hit his signal. When he didn't, Doris eventually made a sound, and soon after Buzz pushed the right signal. Doris followed suit, and they got their fish. Almost every time the experiment was repeated Buzz pushed the correct switch, leading Dr. Bastian to conclude that dolphins can communicate abstract ideas, such as left and right.
More recently, researchers at the Sea Life Park in Hawaii have been testing dolphins through an underwater touchscreen attached to a computer. There are no food rewards, so the dolphins use the touchscreen solely for intellectual stimulation. The scientists found that the dolphins weren't particularly interested in abstractions, such as geometric patterns or artificial sounds. But they were very excited about touching the screen if it resulted in their seeing videos of other dolphins or hearing dolphin sounds. The next step will be to let dolphins choose video or audio sequences and then try to analyze why they're making those decisions.

Where do the biggest waves in the world break?

The easy answer is Hawaii. These islands are the most isolated land mass on earth surrounded by ample ocean surface for the great storms of the Pacific to generate giant, perfect waves that pulse from deep water into the shallow reefs and lava rock of the Hawaiian island chain (e.g. Jaws, Waimea, Pipeline) However, there are several surf spots that have been discovered and/or exploited in recent years that rival any Hawaiian wave. Mavericks, California is a freezing cold 30 foot beast while Teahupo, Tahiti gives new meaning to the word "thick." Let us not forget Cortes Bank located hundreds of miles off the California coast and the bizarre reefs off the coast of France producing enormous waves for jet-ski tow in surfers

sport of the month: surf

The history of surfing is shrouded in the mists of time, as the origins of surfing are unknown. The art of surfing was first observed by Europeans in 1767, by the crewmembers of the Dolphin at Tahiti. Later, Jackson Crane, an American serving under explorer Captain Cook, was the first American to witness surfing, in Hawaii in 1778.
Surfing was a central part of ancient Polynesian culture. The chief was the most skilled wave rider in the community with the best board made from the best tree. The ruling class had the best beaches and the best boards, and the commoners were not allowed on the same beaches, but they could gain prestige by their ability to ride the surf on their extremely heavy boards.
When the missionaries from Scotland and Germany arrived in 1821, they forbade or discouraged many Polynesian traditions and cultural practices, including, on Hawaii, leisure sports such as surfing and holua sledding. By the 20th century, surfing, along with other traditional practices, had all but disappeared. Only a small number of Hawaiians continued to practice the sport and the art of crafting boards

Around the beginning of the 20th century, Hawaiians living close to Waikiki began to revive surfing, possibly in protest to the illegal overthrow of the Hawaiian Kingdom, and soon re-established surfing as a sport. Duke Kahanamoku, "Ambassador of Aloha," Olympic medalist, and avid waterman, helped expose surfing to the world. Kahanamoku's role was later memorialized by a 2002 first class letter rate postage stamp of the United States Postal Service [1]. Author Jack London wrote about the sport after having attempted surfing on his visit to the islands. Surfing progressed tremendously in the 20th century, through innovations in board design and ever increasing public exposure.
Surfing's development and culture was centered primarily in three locations: Hawaii, Australia, and California. Until the 1960s, it had only a small following even in those areas. The release of the film Gidget boosted the sport's popularity immensely, moving surfing from an underground culture into a national fad and packing many surf breaks with sudden and previously unheard of crowds. B-movies and music based on surfing and Southern California beach culture (Beach Party films) as it exploded, formed most of the world's first ideas of surfing and surfers. {Factdate=June 2007} This conception was revised again in the 1980s, with newer mainstream portrayals of surfers represented by characters like Jeff Spicoli from Fast Times at Ridgemont High.
Regardless of its usually erroneous portrayal in the media, true surfing culture continued to evolve quietly by itself, changing decade by decade. From the 1960s fad years to the creation and evolution of the short board in the late 60s and early 70s to the performance hotdogging of the neon-drenched 1980s and the epic professional surfing of the 1990s (typified by Kelly Slater, the "Michael Jordan of Surfing").
Surfing Documentaries have been one of the main ways in which surfing culture grows and replenishes itself, not just as a sport but as an art form, the style and quality of surf films have often tracked well the evolution of the sport