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Denmark's Crown Prince Frederik waves while participating in the KMD Ironman Copenhagen 2013 triathlon in Copenhagen on Aug.
Top 20 Happiest Countries in The World
Denmark's Crown Prince Frederik waves while participating in the KMD Ironman Copenhagen 2013 triathlon in Copenhagen on Aug. 18, 2013.
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View Caption + #2: Troll with Norwegian Flag advertising for a shop in Oslo.
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A giant light installation of the flag of Switzerland, by Swiss artist Gerry Hofstetter, illuminates the north face of the Jungfrau mountain above the city of Thun (bottom), as seen from Oberbuetschel, near Bern on Jan. 1, 2012. The light to the left of the flag is Europe's highest railway station, the Jungfraujoch station, at an altitude of 3,454 meters (11,332 feet).
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People take part in a 2013-meter swim through Amsterdam canals, on Sept. 8, 2013, as part of a charity event to finance research for underexposed diseases.
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Sweden's Princess Madeleine, 30, and U.S.-British banker Christopher O'Neill, 38, leave in a carriage after their wedding ceremony at the royal chapel in Stockholm June 8, 2013.
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Rosanne Howell in Toronto, is a former foster care child. She is shown in this photo on Sept. 6, 2013, after receiving a scholarship through post-secondary studies from Children's Aid Foundation.
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Finnish ice hockey fan Minna Westman puts on contact lenses with the finnish flag prior to the Ice Hockey game France vs Slovakia at the 2013 IIHF World Championships on May 3, 2013 in Helsinki.
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An elderly man speeds down a water chute at Kongressbad public swimming park in Vienna on Aug. 8, 2013.
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Gymnasts do handstands on walkway at Iceland's geothermally heated Blue Lagoon natural swimming pool.
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The Sydney Opera House is lit in a colorful display during a lights and music festival in the city on May 29, 2013.
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A woman smiles as she takes part in a water fight on Rabin Square in Tel Aviv on July 5, 2013. Thousands of people took part in the popular annual event.
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Men carry a crocodile out of the Palma River during a tradition to celebrate Good Friday in Ortega de Santa Cruz, 156 miles (250 km) north of San Jose on April 22, 2011. People of this small town catch a crocodile while hundreds watch from the riverbank during Holy Week celebrations, a tradition going back more than 200 years. The ritual reminds the people of Ortega that the crocodile is the main symbol of their culture.
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New Zealand's Valerie Adams celebrates after winning the women's shot put final at the 2013 IAAF World Championships at the Luzhniki stadium in Moscow on Aug. 12, 2013.
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A Ferrari police car is seen as police officers Badrya Salem AlSowaidi (R) and Maryam Abdulhameed Zarooni laugh in Dubai June 4, 2013. The Dubai Police fleet includes cars from Aston Martin, Bentley Continental GT Coupe, Ferrari, and a recently added Bugatti Veyron.
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A Miss Senorita Panama beauty pageant contestant displays her costume at the Sheraton Hotel in Panama on July 8, 2010.
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Mariachis in Guadalajara on Sept. 5, 2013, take cover from the rain before breaking the Guinness World Record for the largest number of mariachis (700) performing the same song.
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Serena Williams of the United States holds the trophy as she celebrates her win over Victoria Azarenka of Belarus during their 2013 U.S. Open women's singles final match at the USTA Billie Jean King National Tennis Center Sept. 8, 2013 in New York.
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Rory McIlroy of Northern Ireland reacts after becoming golf's new world No. 1 player on the 18th green with his win in the Honda Classic PGA golf tournament at PGA National Golf Club in Palm Beach Gardens March 4, 2012.
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Luxembourg's Andy Schleck rides during the 195 km eighth stage of the 100th edition of the Tour de France cycling race on July 6, 2013 between Castres and Ax 3 Domaines, southwestern France.
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An miner named Ramon flashes a gold letter 'R' on his tooth as he smiles after working in a mine in the southern state of Bolivar on Nov. 15, 2012.
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There are tears of joy and tears of exhaustion. Tears of a clown and crocodile tears. Tears caused by chopping onions and wild monkey tears of the most refined pain.
But, scientifically speaking, a tear is a tear is a tear, right?
Not quite.
Tears come in three types distinct types– basal, reflex and emotional – and they each serve unique functions.
Basal tears – Basal tears are being constantly produced by the eye. They form a thin layer over the iris that protects it from dirt, debris and corneal damage. When everything is functioning normally, basal tear production should go unnoticed, with the exception of adding it to your gratitude list. “Another day without an eye infection? Thanks, basal tears!”
Reflex tears – These are produced in much larger amounts than basal tears because their job is to wash away invaders, like foreign particles or chemical irritants. One of those pesky irritants is syn-propanethial-S-oxide, the chemical in onions that causes you to sob over the cutting board.
Compositionally, reflex tears are distinct from basal tears. They contain special antibodies that help fight off microorganisms. They’re also the type of tear that springs to the corners of the eyes when coughing hard, squinting in bright light, or, god forbid, hit with pepper spray.
Emotional tears – These are the tears you cry at the end of “Out of Africa” or the birth of your first child. They have a different chemical composition than the other two types of tears – they contain stress hormones and a natural painkiller – and experts thinkthey help people return to a calmer, more stable state during times of intense sadness or happiness.
Emotional crying is also part of what makes us human. No other species appears to shed anguished tears or to cry in response to a sublime work of art. This type of weeping may have evolved as a way to signal distressto others without attracting predators.
But never mind all that. Let’s get to the real question: do crocodiles really cry? Yep, but not the tears of faux remorse they’re said to shed.
“Crocodiles appear to produce tears all the time,” reptile expert Adam Britton told National Geographic.”Their function is — like our own tears — to lubricate the eye. This may be even more relevant for crocodiles because they have a third eyelid.”