A clock showing a countdown to the start of the London 2012 Olympics is unveiled on March 14, 2011 in London, England. The clock is starting five hours from midnight when 6.6 million tickets for the Olympics will become available and 500 days before the Games start. There is a six-week window to apply for tickets on the London 2012 website.

Artist Heather Dewey-Hagborg's 'Stranger Visions', comprising of 3D printed faces extracted from DNA taken from discarded cigarette butts and chewing gum, is displayed at the Big Bang Data exhibition at Somerset House on December 2, 2015 in London, England. The show highlights the data explosion that's radically transforming our lives. It opens on December 3, 2015 and runs until February 28, 2016 at Somerset House. (Photo by Peter Macdiarmid/Getty Images for Somerset House)

“Wells Cathedral is a Church of England cathedral in Wells, Somerset, England. Built between 1175 and 1490, Wells Cathedral has been described as “the most poetic of the English Cathedrals”. The Wells clock, an astronomical clock, is located in the north transept. The surviving mechanism, dated to between 1386 and 1392, was replaced in the 19th century, and was eventually moved to the Science Museum in London, where it continues to operate. It is the second-oldest surviving clock in England”. – Wikipedia

Photo: The clock face of world's oldest continually-working mechanical clock is seen as it is hand wound for the very last time on August 21, 2010 in Wells, England. (Photo by Matt Cardy/Getty Images)

An arm holding a giant gun appears to explode through a wall, while elsewhere a man walks a tiger on a leash. These breathtaking pencil drawings are the work of 31-year-old artist Ben Heine, who lives and works in Rochefort, Belgium. The “anamorphic illusions”, part of the artist's “Pencil Vs Camera” series, appear slightly distorted unless viewed from the exact same perspective in which they were created. Photo: Visual artist Ben Heine at work in his studio while he creates one of his “anamorphic illusions” in Rochefort, Belgium. (Photo by Ben Heine/Barcroft Media)

The Prague astronomical clock, or Prague orloj, is a medieval astronomical clock located in Prague, the capital of the Czech Republic. The clock was first installed in 1410, making it the third-oldest astronomical clock in the world and the oldest one still working.

“Ben Heine (born 12 June 1983 Abidjan, Ivory coast) is a Belgian multidisciplinary artist. Starting as a painter and political cartoonist, he became more widely known in 2011 for his “Pencil vs Camera” and “Digital Circlism” projects”. – Wikipedia (Photo by Ben Heine; Source: Flickr)