This year will have an extra ‘leap second’ added to the end of it, making it ever-so-slightly longer than 2015.
While one second may not seem like much, it needs to be added because the Earth does not move with a regular rotation. Sometimes it speeds up and sometimes it slows down. This shift is the result of the braking action of the ocean tides caused by the gravitational forces of the moon. This gradually slows down the Earth’s spin over time and causes astronomical time to differentiate from atomic time.
To make up for this, leap seconds have been added to the clock as needed since 1972. This helps bridge the gap between the both systems and creates one cohesive time.
“Historically, time was based on the mean rotation of the Earth relative to celestial bodies and the second was defined in this reference frame,” explained Geoff Chester, a public affairs officer at the U.S. Naval Observatory, according to The Huffington Post.
One second may not seem like much, but that gap needs to be filled. If the extra seconds were not added, the clocks would have a three-minute by 2100 and a 30-minute difference by 2700.
Though the changes do not mean much to the average person, they are important for digital systems and telecommunication technology across the world. For example, a leap second discrepancy in 2012 caused problems on many popular websites, such as Instagram, Reddit, and Netflix. In addition, discrepancies have implications for the way scientists map planets, as well as the universe itself.
“Think about Juno in orbit around Jupiter,” said Jean Dickey, a researcher at NASA’s Jet Propulsion Laboratory, according to Tech Times. “With all our antennas on Earth, an error in time means an error in Earth rotation, which would end up being a navigation error. It could really wreak havoc with the mission.”