A new LED light fixture is secured to the side of a lift as crews replace existing street lights August 1, 2011 in Las Vegas, Nevada. The new energy-efficient fixtures are expected to reduce the city's annual electricity use by eight million kilowatt hours, saving about USD 400,000. The city estimates the LEDs will last about 15 years, nine years longer than the current lights. Funding for the project comes from federal energy conservation bonds and an American Recovery & Reinvestment Act grant. The city plans to replace all of its 50,000 streetlights after more funding is secured. (Photo by Ethan Miller/Getty Images)

“Thor Heyerdahl (October 6, 1914, Larvik, Norway – April 18, 2002, Colla Micheri, Italy) was a Norwegian ethnographer and adventurer with a background in zoology and geography. He became notable for his Kon-Tiki expedition, in which he sailed 8,000 km (4,300 miles) by raft from South America to the Tuamotu Islands. All his expeditions are shown in the Kon-Tiki Museum, Oslo”. – Wikipedia

Photo: Norwegian anthropologist Thor Heyerdahl with a model of the balsa raft “Kon-Tiki” on which he drifted 4,300 miles from Peru to the Tuamotu Islands, proving his theory that Polynesia could originally have been populated by South Americans. (Photo by Express/Express/Getty Images). 1950

“Burning Man is a week-long annual event held in the Black Rock Desert in northern Nevada, in the United States. The event starts on the Monday before the American Labor Day holiday, and ends on the holiday itself. It takes its name from the ritual burning of a large wooden effigy on Saturday evening. The event is described by many participants as an experiment in community, radical self-expression, and radical self-reliance”. – Wikipedia

Photo: A fireball billows up from a 52-foot tall wooden man as it goes up in flames September 2, 2000 during the15th annual Burning Man festival in the Black Rock Desert near Gerlach, Nevada. Despite high winds, dust storms, and a bit of rain, some 27,000 people camped out on a remote desert playa, or dry lake, for the week-long counter-cultural celebration of art and “radical self-expression”. (Photo by David McNew/Newsmakers)

“Jacob «Jack» Kevorkian (May 26, 1928 – June 3, 2011), commonly known as “Dr. Death”, was an American pathologist, euthanasia activist, painter, composer and instrumentalist. He is best known for publicly championing a terminal patient's right to die via physician-assisted suicide; he said he assisted at least 130 patients to that end. He famously said, «dying is not a crime»”. – Wikipedia

Photo: The “Thanatron”, often referred to as the “Death Machine”, is displayed during a press preview of an auction of the personal effects of Dr. Jack Kevorkian at the New York Institute of Technology on October 27, 2011 in New York City. The device was reportedly used by over 100 of Dr. Kevorkian's patients to terminate their lives. (Photo by Mario Tama/Getty Images)

“A Double Eagle is a gold coin of the United States with a denomination of $20. (Its gold content of 0.9675 troy oz was worth $20 at the then official price of $20.67/oz). The coins are made from a 90% gold (0.900 fine = 21.6 kt) and 10% copper alloy”. – Wikipedia

Photo: A “Double Eagle” gold twenty dollar coin is displayed above a catalogue picture showing the reverse side of the coin at Goldsmith's Hall on March 2, 2012 in London, England. Nearly half a million of these coins were originally minted in the midst of the Great Depression in the US. Only 13 are known today after the rest were melted down before they ever left the US Mint, sacrificed as part of a strategy to stabalise the American economy. In 2002 a Double Eagle sold at auction for $7.6 million. (Photo by Peter Macdiarmid/Getty Images)

“By 1969, the fashion choices of tens of millions of young American men and women were as variegated and ever-evolving as the world around them. Cultural transformation was an irresistible force during the Sixties, and across America and around the globe civil rights, women’s and gay liberation, the sexual revolution and, of course, the explosive soundtrack of R&B, soul and rock and roll informed everything from politics to fashion”. – LIFE. Photo: Corona del Mar High School students Kim Robertson, Pat Auvenshine and Pam Pepin wear “hippie” fashions, 1969. (Photo by Arthur Schatz/Time & Life Pictures)

A 19th century bicycle safety lock is displayed in an old frame in the Museum of Domenico Agostinelli in Dragona, near Rome October 30, 2014Italian collector Domenico Agostinelli, 74, has a passion that has led him over the past 60 years to pick up and collect things of all types, from antique art to everyday objects of the past and present. His collection includes a 65-million-year-old dinosaur egg, meteor fragments, a car that once belonged to American mob boss Al Capone, a lock of hair of Italian national hero Giuseppe Garibaldi, toys, weapons, musical instruments of all kinds and many more. (Photo by Tony Gentile/Reuters)

Shoppers wrestle over a television as they compete to purchase retail items on “Black Friday” at an Asda superstore in Wembley, north London November 28, 2014. Britain's high streets, malls and online sites were awash with discounts on Friday as more retailers than ever embraced U.S.-style “Black Friday” promotions, seeking to kickstart trading in the key Christmas period. In the United States the Friday following the Thanksgiving Day holiday is called Black Friday because spending usually surges and indicates the point at which American retailers begin to turn a profit for the year, or go “into the black”. (Photo by Luke MacGregor/Reuters)