Does anyone have the time?<\/h2>\n\n\n\n\n![\"Image](\"https:\/\/miro.medium.com\/max\/960\/1*zFR06mnd1lOcMDKyF3sn_A.jpeg\")
<\/i><\/a>The FOCS-1 atomic clock in Switzerland, seen here, is one of the most accurate timekeeping devices in the world, accurate to one second every 30 million years. Public domain image.<\/figcaption><\/figure>\n<\/div>\n<\/div>\n<\/div>\n<\/figure>\nAtomic clocks make it possible to measure the length of a day with unprecedented accuracy. Since their development in the 1960\u2019s, researchers have understood that the rotational rate of the <\/span>Earth<\/a> <\/span>changes over time. Due to these variations, leap seconds have been added 28 times over the last 48 years.<\/p>\nHowever, or the first time ever, scientists are now talking about the possible need for a negative leap second \u2014 officially removing a second this year, making up for the increased rotational speed of Earth.<\/p>\n
So why is the <\/span>Earth<\/a> <\/span>is spinning faster than normal?<\/p>\nOfficial measurements of time derive from comparing the time from a network of 400 hundred atomic clocks, to the position of stars in the sky. (Interestingly, stars produce a different measurement of the length of a day, known as sidereal time. But, astronomers convert as needed).<\/p>\n
Atomic clocks reveal that the time it takes for <\/span>Earth<\/a> <\/span>to rotate through a complete day changes regularly, driven by atmospheric and oceanic currents, movements in the molten core of our planet, and even changes in atmospheric pressure.<\/p>\nDue to these effects, Coordinated Universal Time (UTC) \u2014 the standard by which all clocks are set \u2014 needs to occasionally be updated. In 2016, an extra leap second was added to the UTC time to make up for this difference. Since 1972, leap seconds have been added 28 times, usually at the end of June or December.<\/p>\n
\u201cBefore UTC was introduced as the world time standard in 1972, GMT was a solar time standard that also acted as a reference point to determine local times worldwide. Today, GMT is a common time zone deriving its local time from UTC,\u201d <\/span>Konstantin Bikos<\/a> <\/span>explains for TimeandDate.com.<\/p>\nStrangely, 2020 didn\u2019t seem to go by quickly at all\u2026<\/h2>\n\n\n\n\n![\"Image](\"https:\/\/miro.medium.com\/max\/950\/1*q3JeJvQKoRfTCnLQaHUL7Q.jpeg\")
<\/i><\/a>Crystals of Cesium-133, trapped in argon gas. Image credit: Dennis S.K.<\/figcaption><\/figure>\n<\/div>\n<\/div>\n<\/div>\n<\/figure>\nHowever (believe it or not), 2020 was actually the shortest year on record. Each day was roughly 1\/20th of a millisecond shorter than normal. That difference, accumulated over the course of <\/span>2021<\/a>, would result in clocks drifting roughly 1\/50 of a second off of the rotational period of Earth.<\/p>\n\u201c\u2026[A]n average day in 2021 will be 0.05 ms shorter than 86,400 seconds. Over the course of the entire year, atomic clocks will have accumulated a lag of about 19 ms\u2026 In fact, the year 2021 is predicted to be the shortest in decades. The last time that an average day was less than 86,400 seconds across a full year was in 1937,\u201d Graham Jones and Konstantin Bikos report for <\/span>TimeandDate.com<\/a>.<\/p>\n[Read:
Atomic clocks make it possible to measure the length of a day with unprecedented accuracy. Since their development in the 1960\u2019s, researchers have understood that the rotational rate of the <\/span>Earth<\/a> <\/span>changes over time. Due to these variations, leap seconds have been added 28 times over the last 48 years.<\/p>\n However, or the first time ever, scientists are now talking about the possible need for a negative leap second \u2014 officially removing a second this year, making up for the increased rotational speed of Earth.<\/p>\n So why is the <\/span>Earth<\/a> <\/span>is spinning faster than normal?<\/p>\n Official measurements of time derive from comparing the time from a network of 400 hundred atomic clocks, to the position of stars in the sky. (Interestingly, stars produce a different measurement of the length of a day, known as sidereal time. But, astronomers convert as needed).<\/p>\n Atomic clocks reveal that the time it takes for <\/span>Earth<\/a> <\/span>to rotate through a complete day changes regularly, driven by atmospheric and oceanic currents, movements in the molten core of our planet, and even changes in atmospheric pressure.<\/p>\n Due to these effects, Coordinated Universal Time (UTC) \u2014 the standard by which all clocks are set \u2014 needs to occasionally be updated. In 2016, an extra leap second was added to the UTC time to make up for this difference. Since 1972, leap seconds have been added 28 times, usually at the end of June or December.<\/p>\n \u201cBefore UTC was introduced as the world time standard in 1972, GMT was a solar time standard that also acted as a reference point to determine local times worldwide. Today, GMT is a common time zone deriving its local time from UTC,\u201d <\/span>Konstantin Bikos<\/a> <\/span>explains for TimeandDate.com.<\/p>\n However (believe it or not), 2020 was actually the shortest year on record. Each day was roughly 1\/20th of a millisecond shorter than normal. That difference, accumulated over the course of <\/span>2021<\/a>, would result in clocks drifting roughly 1\/50 of a second off of the rotational period of Earth.<\/p>\n \u201c\u2026[A]n average day in 2021 will be 0.05 ms shorter than 86,400 seconds. Over the course of the entire year, atomic clocks will have accumulated a lag of about 19 ms\u2026 In fact, the year 2021 is predicted to be the shortest in decades. The last time that an average day was less than 86,400 seconds across a full year was in 1937,\u201d Graham Jones and Konstantin Bikos report for <\/span>TimeandDate.com<\/a>.<\/p>\n [Read: Strangely, 2020 didn\u2019t seem to go by quickly at all\u2026<\/h2>\n