Workers demonstrate outside the factory of Hua Yang Printing Holdings Co Ltd on October 30, 2007 in Shenzhen of Guangdong Province, China. Over 1,000 workers of the company have blocked the 107 State Highway where the firm is located, to protest against their employer, who owed half a month's salary to the workers. (Photo by China Photos/Getty Images)

“Contrails (short for “condensation trails”) or vapour trails are artificial clouds that are the visible trails of condensed water vapour made by the exhaust of aircraft engines. As the hot exhaust gases cool in the surrounding air they may precipitate a cloud of microscopic water droplets or, if the air is cold enough, tiny ice crystals”. – Wikipedia

Photo: An airplane leaves a vapor trail as it flies in front of he moon on January 17, 2007 above Hanover, Germany. (Photo by Alexander Hassenstein/Getty Images)

Female Chimpanzee “Fifi” eats carrots as she sits in her enclosure at Taronga Zoo on her 60th birthday May 21, 2007 in Sydney, Australia. Fifi is the oldest of the Zoo's chimp population, which consists of 19 individuals. (Photo by Ian Waldie/Getty Images)

Myoung Ho Lee‘s 2007 Tree series is about as peaceful and serene as the scenery itself. In the series, the young South Korean photographer touches upon the subjects of physical isolation and visual confirmation. By placing the tree in front of a stark white background, Lee creates a false separation that plays a delightful game with the mind’s eye.

Li Yuming, a local farmer who is interested in scientific invention, works on his unfinished miniature submarine “Xiaguang V” on the outskirts of Wuhan, capital of central China's Hubei province August 24, 2007. “Xiaguang V”, which is 3-metre long, 1.2-metre in height, has a maximum diving depth of 20 metres, and can hold two adults and one child at the same time. The submarine will be used for tour after safety test, local media said. (Photo by Reuters/Stringer)

American soldiers with the 173rd Airborne Brigade Battle Company, on a battalion-wide mission in the Korengal Valley, looking for caves, weapons caches and known Taliban leaders, 2007. Tanner Stichter tends to Spc. Carl Vandeberge in the bushes moments after Vandeberge was shot in the stomach during a Taliban ambush, which killed one soldier and wounded two others. (Photo by Lynsey Addario)

File photo taken on July 24, 2011 shows the scenery of karst landform in Dacai Township under Maonan Autonomous County of Huaijiang, south China's Guangxi Zhuang Autonomous Region. The World Heritage Committee on Monday inscribed an extension of South China Karst, a natural World Heritage Site since 2007, into the UNESCO's World Heritage List. (Photo by Wang Xiufa/Xinhua)

“The National Portrait Gallery, London's annual photographic portrait prize was established in 2003 as the Schweppes Photographic Portrait Prize. In the years 2006 and 2007 it was referred to simply as the Photographic Portrait Prize, while from 2008 new sponsors have resulted in the name, Taylor Wessing Photographic Portait Prize”. – Wikipedia. Photo: “Tic Tac and Tootsie (twin sisters Carrol and Shelly McKean)”. Taylor Wessing photographic portrait prize 2010. (Photo by Jeffrey Stockbridge)