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Planeta este acoperită de apă în proporție de 71%, din care mai puțin de 1% este apă potabilă sau dulce și poate fi consumată în starea ei naturală. Mai concret spus, există aproximativ 1.5 miliarde de km cubi de apă pe Pământ, adică echivalentul a 800 de miliarde de piscine olimpice. Din aceasta, 97% este sărată, 2.1 % este închisă în calotele polare şi mai puţin de 1% este disponibilă ca apă potabilă. Cea mai mare parte din apa potabilă a planetei o putem găsi în ghețari.

360.864 replies on “Mai puțin de 1% din apa de pe Pământ este potabilă.”

GreggHersays:

A brief history of sunglasses, from Ancient Rome to Hollywood
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Sunglasses, or dark glasses, have always guarded against strong sunlight, but is there more to “shades” than we think?

The pupils of our eyes are delicate and react immediately to strong lights. Protecting them against light — even the brilliance reflected off snow — is important for everyone. Himalayan mountaineers wear goggles for this exact purpose.

Protection is partly the function of sunglasses. But dark or colored lens glasses have become fashion accessories and personal signature items. Think of the vast and famous collector of sunglasses Elton John, with his pink lensed heart-shaped extravaganzas and many others.

When did this interest in protecting the eyes begin, and at what point did dark glasses become a social statement as well as physical protection?
The Roman Emperor Nero is reported as holding polished gemstones to his eyes for sun protection as he watched fighting gladiators.

We know Canadian far north Copper Inuit and Alaskan Yupik wore snow goggles of many kinds made of antlers or whalebone and with tiny horizontal slits. Wearers looked through these and they were protected against the snow’s brilliant light when hunting. At the same time the very narrow eye holes helped them to focus on their prey.

In 12th-century China, judges wore sunglasses with smoked quartz lenses to hide their facial expressions — perhaps to retain their dignity or not convey emotions.

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