Maintenance engineer Darren Unsworth cleans one of the crystal Edwardian chandeliers that illuminate Blackpool Tower Ballroom on January 16, 2012 in Blackpool, England. Blackpool's famous Tower Ballroom is undergoing an annual spring clean which includes lowering the ornate chandeliers where each shard of crystal is cleaned for the coming season of dancing. The dance floor consisting of 30,602 blocks of mahogany, oak and walnut is also sanded and polished to give the perfect dance floor. (Photo by Christopher Furlong/Getty Images)

Wanwisa, a Lao Yi Lai Heng Chinese opera performer waits backstage at the Plub Plachai temple on January 25, 2012 in Bangkok, Thailand. The traditional Chinese art form involving music, singing, martial arts and acting has a history of more than 500 years. There are about 30 members working with the group doing specials shows all week to celebrate the Chinese New year. The Chinese opera is popular in many parts of China, Malaysia, Singapore, Thailand and Macau. (Photo by Paula Bronstein/Getty Images)

Marcos Trujillo cleans the engines of a boat made by Contender in preparation for tomorrow's opening day of the four day long Progressive Insurance Miami International Boat Show at the Miami Beach Convention Center on February 15, 2012 in Miami Beach, Florida. The boat show features more than 3,000 boats and 2,000 exhibitors from all over the globe. (Photo by Joe Raedle/Getty Images)

Local actor Colin Retallick plays the role of St. Piran during the annual processional play to celebrate St. Piran, patron saint of tinners and regarded by many as Cornwall's premier saint, on March 4, 2012 in Perranporth, England. (Photo by Matt Cardy/Getty Images)

These photographs are the work of urban explorer Dr Bradley Garrett who made headlines back in 2012 when he posted a series of snaps from the top of The Shard skyscraper while it was still under construction. Garrett, now a researcher at the University of Oxford, took these shots during his time with the London Consolidation Crew (LCC), a loose collection of urban explorers based in the English capital. Photo: Bradley Garrett stands on the edge of the Ritz-Carlton Chicago as lightning strikes in the distance in Chicago, US. (Photo by Bradley L. Garrett/Barcroft Media)

This picture taken on December 17, 2013 shows people taking photos of a pole dancer (R) practising after it snowed in Tianjin during a promotional event by members of China's national pole dancing team and students of the sport. China set up its first national pole dancing team in Tianjin in 2012 in order to compete in the World Pole Dancing Championships. (Photo by AFP Photo)

Members of Germany's elite police unit, the Spezialeinsatzkommando, or SEK, demonstrate an abseil deployment from a helicopter during a media event on March 20, 2012 in Minden, Germany. The SEK is the special response team of Germany's state police force and typically deploys in high-risk situations, such as bank robberies, hostage takings and the arrest of armed and dangerous fugitives. (Photo by Thomas Starke/Getty Images)

Space shuttle Discovery sits atop NASA's 747 Shuttle Carrier Aircraft (SCA) ready to transport it from Kennedy Space Center to the Washington D.C., on April 17, 2012 in Cape Canaveral, Florida. Following the retirement of the shuttle fleet, Discovery will fly to Washington for display at the Smithsonian's National Air and Space Museum. (Photo by Lofty Ambitions)