Fireworks explode over Elizabeth Tower housing the Big Ben clock in London. (Photo by Kirsty Wigglesworth/Associated Press)

People cheer as the ball drops at midnight in Times Square on January 1, 2015 in New York City. An estimated one million people from around the world are expected to pack Times Square to ring in 2015. (Photo by Andrew Theodorakis/Getty Images)

Craig Jobbins, first buyer of the new iPad to leave the Apple Store, poses for photographers in Covent Garden on March 16, 2012 in London, England. (Photo by Matthew Lloyd/Getty Images)

Chinese archaeologists announced the discovery of 110 life-sized terracotta warriors, guarding the tomb of Qin Shi Huang, China's first emperor.

Photo: Archaeologists work on a terracotta warrior in the third excavation of pit one at the Terracotta Warriors and Horses Museum in Xi'an in northwest China's Shaanxi province Saturday, June 9, 2012. (Photo by AP)

Actor Jack Black attends the New York premiere of “Kung Fu Panda 2” at Ziegfeld Theatre on May 24, 2011 in New York City. (Photo by Stephen Lovekin/Getty Images)

United States Marines perform a fighting demonstration in Times Square as part of Fleet Week festivities May 27, 2011 in New York City. Fleet Week, which has been held in New York since 1984, brings thousands of military members to the city where they engage the public with numerous activities, demonstrations, tours and contests. Fleet Week concludes on Memorial Day with a military flyover to honor those killed while serving in the military. (Photo by Spencer Platt/Getty Images)

Two De Brazza's monkeys stand together at Port Lympne Wild Animal Park on June 21, 2011 in Hythe, England. Port Lympne has welcomed a host of new arrivals this year with wildebeest, colobus monkeys, gorillas and rhinos all adding to the current stock. Port Lympne and Howletts Wild Animal parks were set up by the late John Aspinall to protect and breed rare and endangered species and, where possible, return them to safe areas in the wild. The Aspinall Foundation which runs the parks also manages two gorilla rescue and rehabilitation projects in the central African countries of Gabon and Congo where they have successfully reintroduced over 50 gorillas to the wild. (Photo by Dan Kitwood/Getty Images)

Reenactors playing the roll of Kentucky volunteers, fighting for the United States, fire muskets during a reenactment of the Battle of New Orleans in the War of 1812, marking its bicentennial in Chalmette, Louisiana, January 10, 2015. The participants, some of whom have travelled thousands of miles to join in the event, recreated the five clashes that comprise the battle, which some historians say was key in making the British honor the terms of a peace treaty signed in late 1814. (Photo by Lee Celano/Reuters)