What makes a watch the most valuable in the world? It’s supercomplicated – literally. In 1925 banker Henry Graves Jr. (considered the greatest watch collector of the 20th century) commissioned Patek Philippe to create a unique gold pocket watch. When Graves finally received it – eight years later – it was the most complex timepiece ever created by human hands... (Photo by Suzanne Plunkett/Reuters)

Men help remove messages and prayers written by thousands of people addressed to God from the cracks in the Western Wall in preparation for the up coming Jewish Passover holiday on March 28, 2012 in Jerusalem's old city, Israel. All the notes once collected will be buried in a special place at the Mount of Olives.according tro Jewish law. Passover begins in the evening of Friday, April 6 and commemorates the story of the Exodus where the ancient Israelites were freed from slavery in Egypt. (Photo by Uriel Sinai/Getty Images)

(L-R) U.S. President Barack Obama, Queen Elizabeth II and First Lady Michelle Obama arrive at Winfield House, the residence of the Ambassador of the United States of America, in Regent's Park, on May 25, 2011 in London, England. The 44th President of the United States, Barack Obama, and First Lady Michelle are in the UK for a two day State Visit at the invitation of HM Queen Elizabeth II. Last night they attended a state banquet at Buckingham Palace and today's events include talks at Downing Street and the President will address both houses of Parliament at Westminster Hall. (Photo by Yui Mok - WPA Pool/Getty Images)

Joseph Szabo was a frustrated high-school teacher in need of inspiration – so he started photographing his students, and captured all the angst and excitement of being caught between childhood and adulthood. Here: “Priscilla”, 1969. (Photo by Joseph Szabo/Courtesy of Michael Hoppen Gallery/The Guardian)

REUTLINGEN, GERMANY - NOVEMBER 17: Students hang out finished parchment leather at the LGR (Lederinstitut Gerberschule Reutlingen) tannery school on November 17, 2010 in Reutlingen, Germany. Even in early antiquity and up their hair or dried goat and sheep skins were used as material for documents. In the small Asian city Pergamon these skins were processed in large quantities for this purpose, so they formed the main trading arm of the city, of which the name is parchment is derived. In medieval times, reached the parchment is of great importance, it was such as France's production under the supervision of the University of Paris. Even now, important documents, placed on their unlimited shelf life as possible large value (eg diplomas, addresses, memory, writings, documents for primary and keystones) written on parchment...

Sustainable development goal target 12.5 is to reduce waste. But with a planet increasingly dependent on technology, is that even possible? As of today, over 30m tonnes of electronic waste has been thrown out so far this year, according to the World Counts. Most e-waste is sent to landfills in Asia and Africa where it is recycled by hand, exposing the people who do it to environmental hazards. Kai Loeffelbein’s photographs of e-waste recycling in Guiyu, southern China show what happens to discarded computers. (Photo by Kai Loeffelbein/laif Agentur)

“The technology was designed to address the risk associated with head-on or nearly head-on motorcycle collisions, which account for a large percentage of motorcycle crashes. The airbag was designed to deploy during a severe frontal collision in which a rider could be thrown forward from the motorcycle. Once deployed, the airbag stands upright in front of the rider to help absorb the rider’s kinetic energy prior to leaving the motorcycle”. – Ohio.Honda.com

Photo: Honda Motor Co., Ltd.'s world's first production motorcycle airbag system is introduced at a press conference at Honda's HQ on September 8, 2005 in Tokyo, Japan. The motorcycle airbag system to be installed to lessen the injuries of the rider is comprised of the airbag module that include the airbag and the inflator, crash sensors that monitor acceleration changes and an ECU that performs calculation to determine when a collision is occuring. (Photo by Junko Kimura/Getty Images)

“Mario Armando Lavandeira, Jr. (born March 23, 1978), better known as Perez Hilton (a play on “Paris Hilton”), is an American blogger and television personality. His blog, Perezhilton.com (formerly PageSixSixSix.com), is known for posts covering gossip items about musicians, actors and celebrities. He is also known for posting tabloid photographs over which he has added his own captions or “doodles”. His blog has garnered negative attention for its attitude, its active “outing” of alleged closeted celebrities and its role in the increasing coverage of celebrities in all forms of media.” – Wikipedia

Photo: Blogger Perez Hilton poses with a wombat during a visit to Taronga Zoo on June 13, 2011 in Sydney, Australia. (Photo by Perezhilton.com via Getty Images)