Where else but Times Square on New Year's Eve could you get into a free party with Taylor Swift and “Gangnam Style” singer Psy? Of course, you'll be barricaded in with thousands of other people, unable to move your limbs, but it will surely be worth it to celebrate the annual ritual of a large ball moving down a pole. Just when did we start celebrating the new year with this sort of thing, and how is it timed to finish dropping at precisely midnight?


The New Year's Eve ball drop tradition traces its origins back to 19th-century timekeeping. In 1833, the Royal Observatory in Greenwich, England, installed a ball that would drop down a pole at 1 o'clock every afternoon to help ship captains calibrate their instruments. Other places besides Times Square use time-balls throughout the year, like the U.S. Naval Observatory, where a ball drops at noon every day.


But of course, the most famous ball drop these days happens in the city that never sleeps. The ball that will drop in Times Square Monday night is a geodesic sphere 12 feet across, sporting 2,688 Waterford Crystal triangles and illuminated by 32,256 LED lights.


It's a much more elaborate affair than the first New Year's Eve ball, used on the maiden voyage that marked the end of 1907 and the beginning of 1908. That was an iron and wood affair that weighed a comparatively svelte 700 pounds and was lit by 100 light bulbs. Throughout the decades, a succession of balls have made the trip down to herald the new year. A wholly iron ball was used starting in 1920, replaced in 1955 by a lighter aluminum one. In the 1980s, the ball was transformed into a Big Apple with the help of an artificial stem and red light bulbs.


In 1995, the ball, now back to a basic spherical shape, sported rhinestones and strobe lights and was also lowered with the aid of computers. In 2000, Waterford took the helm and invited revelers to gaze into the new millenium with the aid of a wholly crystal New Year's Eve Ball.


Though New York City Mayor Michael Bloomberg will push a button with a minute to go, that gesture doesn't actually initiate movement of the ball. A technician keeps an eye on the official time and, when the moment strikes, hits the real button that lowers the ball electronically.


“What we do is we get a global positioning system signal from the atomic clock in Colorado, which is the main clock the government uses to guide all of its electronic devices, whether it's missiles or planes or anything like that,” Tim Tomkins of the Times Square Business Improvement District told NY1 in 2003.


Once the electronic gears are set in motion, the ball will drop 70 feet in 60 seconds to ring in 2013.