Latest news with #ShortestDay
The Independent
6 days ago
- Science
- The Independent
Why are we about to have one of the shortest days ever?
The Earth is currently spinning at its fastest rate since records began, with 5 August predicted to be one of the shortest days ever measured. The shortest day on record occurred on 5 July 2024, measuring 1.66 milliseconds shorter than the average 24-hour rotation. While the Moon's gravity typically slows Earth's rotation, there is no conclusive reason for the current acceleration, though melting polar ice caps are a suggested factor. Scientists have proposed introducing a 'negative leap second' to compensate for the lost time, which would require adjusting all global clocks. This would be the first time a second has been subtracted, raising concerns among experts about potential unprecedented problems for current computing infrastructure.
The Independent
6 days ago
- Science
- The Independent
Earth is spinning faster and is about to see one of its shortest days ever
The Earth is spinning at its fastest rate since records began, and astronomers predict that 5 August will be one of the shortest days ever measured. New estimates released this month suggest that the first Tuesday of August will be around 1.25 milliseconds shorter than it should be. The average rotation of our planet is 24 hours, or 86,400 seconds, however there are several variables that cause Earth to spin faster or slower. The Moon's gravitational influence on Earth typically causes it to slow time over time and for days to lengthen. There is no conclusive reason for why Earth's rotation is accelerating, though a 2024 study suggested that melting polar ice caps and rising sea levels could be influencing it. The shortest day ever recorded was on 5 July, 2024, measuring 1.66 milliseconds shorter, with recent years seeing the rotation speeding up. Scientists have proposed a negative leap second to compensate for the lost time, meaning all of the world's clocks will need to be adjusted. 'This is an unprecedented situation and a big deal,' said geophysicist Duncan Agnew from the University of California, who wrote about the issue in a paper published in the journal Nature last year. 'It's not a huge change in the Earth's rotation that's going to lead to some catastrophe or anything, but it is something notable. It's yet another indication that we're in a very unusual time.' There have been 27 leap seconds added to Coordinated Universal Time (UTC) since 1972, when the present form of the time standard was adopted, in order to match atomic time to astronomical time. This would be the first time that a second has been subtracted, and it is not clear how current computing infrastructure would cope with the shift. Patrizia Tavella from the Time Department at the International Bureau of Weights and Measures, wrote in an accompanying article to the Nature paper that any potential risks should be assessed before a negative leap second is applied. 'A negative leap second has never been added or tested,' she said, 'so the problems it could create are without precedent.'
Yahoo
7 days ago
- Science
- Yahoo
July 22 will be the second-shortest day of the year, scientists say
Tuesday, July 22 will be the second-shortest day of the year, as Earth completes a full rotation in less time than usual. The planet on Tuesday will experience a shorter rotation than the typical 24 hours, though not by much: 1.34 milliseconds less than usual, according to MORE: Climate change is altering the length of days on Earth, according to new research Typically, we think of the shortest day in the Northern Hemisphere as Dec. 21 or 22, which coincides with the winter solstice – July 21 or 22 in the Southern Hemisphere – which is the point at which the hemisphere is tilted farthest away from the sun. In those instances, however, it's only the number of hours of daylight that are affected, and not the length of time it takes for the Earth to make a full rotation on its axis. The 1.34-millisecond discrepancy in Tuesday's length is explained by differences in the gravitational pull between the Earth and the moon, which causes the Earth to spin more quickly, according to the Lunar and Planetary Institute. In recent years, Earth has broken its own speed records several times, including on July 5, 2024 – the shortest day ever measured, when the planet's full rotation was completed 1.66 milliseconds faster than usual, according to PHOTO: Spinning Globe This year, July 10 was measured as the shortest day of the year, with a full rotation occurring 1.36 milliseconds faster than normal. Aug. 5 is expected to be the third-shortest day of the year, projected to be 1.25 milliseconds shorter than usual. Earth completes one full rotation on its axis in 24 hours, or about 86,400 seconds, plus or minus a millisecond or so, according to Before 2020, Earth's shortest length of day was just 1.05 milliseconds shorter than usual. MORE: What to know about the winter solstice, the shortest day of the year If current trends continue, a full second may need to be subtracted from atomic clocks in the near future to accommodate for a "negative leap second," according to The system of leap seconds was introduced in the 1970s, according to Time and Date. While there have been dozens of positive leap seconds, in which a second was added, there has never been a negative leap second. The International Earth Rotation and Reference Systems Service, which monitor's the Earth's rotation, also determines whether to add or subtract a second. In its early days – about 4.5 billion years ago – Earth was spinning at a much faster rate, according to the Lunar and Planetary Institute. A full rotation only lasted between three and six hours. MORE: Melting polar ice is changing the Earth's rotation and affecting how we measure time: Study During the mid-Proterozoic period – between 2.5 billion years ago and 543 million years ago – the Earth had slowed such that a day lasted about 19 hours, according to a 2023 study published in Nature Geoscience. Since then, the length of an Earth day has slowed to its present 24 hours due to the fact that the moon's gravitational pull "steals" some of energy Earth uses to spin, in addition to causing tidal friction, according to the Institute. Additionally, climate change is causing days on Earth to become longer due to the melting of ice at the poles, according to a study published in the Proceedings of the National Academy of Sciences. As the poles melt, the redistribution of mass from the resulting sea-level rise also is increasing the length of a day, the researchers found.
Yahoo
7 days ago
- Science
- Yahoo
Is Earth's rotation speeding up? July 22 will be second shortest day in history
Earlier this month, the Earth spun just a bit faster than usual on July 9 and is expected to do so again on July 22 and Aug. 5, according to the website TimeAndDate. Over a millisecond was reportedly shaved off the clock on July 9, but the shortest day out of all three predicted will be in August. This shortening is due to the moon's position relative to Earth and its influence on the planet's rotation. Here's what to know about why Earth's rotation is speeding up, and how it is shortening three days this summer. Is Earth's rotation speeding up? Earth takes 24 hours to complete a full rotation in a standard day, equal to exactly 86,400 seconds. If a standard day is shortened or lengthened by a number of milliseconds, that added or detracted time is referred to as "length of day," according to the website TimeAndDate. Until 2020, the shortest "length of day" ever recorded by atomic clocks was -1.05 ms, meaning that Earth completed one daily rotation in 1.05 milliseconds less than 86,400 seconds. "Since then, however, Earth has managed to shatter this old record every year by around half a millisecond," astrophysicist Graham Jones wrote for TimeAndDate. That culminated on July 5, 2023, with the shortest day of all time, with a "length of day" of -1.66 ms, according to Jones. While the variations are expected, recent research suggests that human activity is also contributing to Earth's changing rotation. Researchers at NASA calculated that dwindling ice and groundwater and rising seas have actually increased the length of our days since 2000 by 1.33 milliseconds per century . A photo of Earth rising over the moon's horizon taken in 1968 by astronaut Bill Anders How short will the day be on July 22 On July 22, scientists predicted a -1.38 ms "length of day." This is a little bit faster than July 9, , which had about a -1.30 ms "length of day," according to TimeAndDate. August 5 is expected to the most truncated at -1.51 ms "length of day." On these days, the moon will be at its furthest from the Earth's equator, changing its gravitational pull and causing our planet to spin just a tiny bit faster on its axis, according to science news website LiveScience. Will the sped-up day be noticeable? Of course, you're unlikely to notice such a minuscule difference in your standard 24-hour day. But scientists who track and operate atomic clocks may be facing a bit of a predicament. First introduced in the 1950s, atomic clocks replaced how scientists previously measured the length of a day by tracking the Earth's rotation and the position of the sun. The clocks are also capable of measuring in billionths of a second, or nanoseconds, which are synchronized globally to Coordinated Universal Time (UTC.) If the clocks are thrown off even a tiny amount, it could also throw off computers, servers, GPS signals, and other networks that rely on accurate times, David Gozzard, an experimental physicist at the University of Western Australia, told the Guardian. This article originally appeared on The Providence Journal: Earth will spin faster today, creating second shortest day in history
Yahoo
22-07-2025
- Science
- Yahoo
World set for second shortest day on record on Tuesday
Anyone trotting out the well-worn "it's been a long day" line on July 22 might end up having to rephrase, as Earth is set for its second shortest day on record due to an inexplicable recent acceleration of the planet's rotation. The latest estimate is that July 22 will end an imperceptible 1.34 milliseconds off the full 86,400 seconds or 24 hours, according to the US Naval Observatory and the International Earth Rotation and Reference Systems Service (IERS). That's a fraction of a blink of an eye, which lasts around 100 milliseconds. Blink and you'll miss it, in other words. But there is even a chance that July 22 could end up breaking the record for the shortest-ever day, which was clocked on July 5 last year. Either way, July 22 is just the latest in a series of shorter days this year as Earth spins faster than usual. If the trend continues, it will require an adjustment to clocks sometime down the line, perhaps by shaving off a second by 2029. After all, real time and time recorded on atomic clocks has to match up as best as can be achieved, as communications devices and satellites could otherwise be thrown off-kilter. Records have only been kept since 1973, following the invention of atomic clocks accurate and precise enough to allow for such detailed and intricate timekeeping. Why Earth is spinning more quickly remains unknown, though scientists have said the most likely explanation lies deep inside the planet - in the inner and outer cores. Earth's inner core, which is believed to be a solid ball of iron and nickel with its own rotation, was last year reported to have slowed down, according to research published in the journal Nature. Other researchers have detected changes to the Earth's magnetic field, such as a potential weakening that could leave the planet more vulnerable to solar storms. The field is thought to be generated by the Earth's outer core, which appears to be made up of molten metals and acts like a giant dynamo. Solve the daily Crossword
