Latest news with #EarthRotation
Daily Mail
11 hours ago
- Science
- Daily Mail
Scientist warns shortest day in history is coming in WEEKS as Earth's rotation unexpectedly speeds up
A scientist has warned that Earth's rotation is unexpectedly accelerating, leading to the shortest day in history in just a few weeks. Graham Jones, an astrophysicist at the University of London, says Earth's rotation could speed up noticeably on one of three dates this summer, either July 9, July 22, or August 5. On those days, time is predicted to drop by 1.30, 1.38, or 1.51 milliseconds, respectively. Researchers say that although this change will be tiny, it can affect everything from satellite systems and GPS accuracy to how we measure time itself. Leonid Zotov, a scientist at Moscow State University, said: 'Nobody expected this, the cause of this acceleration is not explained.' Since 2020, scientists have noticed that Earth has been spinning slightly faster than usual, but the cause remains a mystery to this day.. Before that, the planet was slowing down over time, due to the moon's gravitational pull, which stretched days into the 24-hour cycle we now live by. Earth normally takes 24 hours, or exactly 86,400 seconds, to complete one full rotation, which is called a solar day. Earth's rotation is not always perfect, as it can shift by a tiny amount over time, a few milliseconds. That is likely due to the Earth's spin being influenced by natural forces, like earthquakes and ocean currents. Melting glaciers, movement in Earth's molten core, and large weather patterns like El Niño can also slightly speed up or slow down the planet's rotation. These changes are measured using atomic clocks, which track time more accurately than regular watches. The recent spin-up has surprised researchers. The fastest day recorded so far was on July 5, 2024, when Earth spun 1.66 milliseconds faster than the standard 24 hours. Although the scientist does not know the exact reason for the acceleration, they are studying what's happening inside the Earth. That includes shifting molten layers in the core, ocean currents, and high-altitude winds as they affect the Earth's spin. Earth is not solid all the way through. Its core is made of hot, swirling liquid metal. As that molten metal moves, it can change the planet's shape and balance, similar to how a figure skater spins faster by pulling in their arms. Ocean currents and jet streams, fast-moving ribbons of air in the atmosphere, also shift mass around the planet, causing small wobbles or changes in spin speed. Scientists are looking at all these pieces together, the moon's orbit, core activity, ocean flow, and wind patterns, to figure out what's going on. Starting in 2020, Earth began breaking its records for the shortest day. That year, July 19 came in 1.47 milliseconds short. On July 9, 2021, there was a 1.47 millisecond drop. In 2022, Earth recorded its shortest day on June 30, shaving off 1.59 milliseconds from the usual 24 hours. In 2023, the rotation slowed slightly, and no new records were set. But in 2024, the speed picked up again. Several days broke the previous records, making it the year with the most consistently short days ever measured. These estimates are based on past observations and computer models, and include systematic corrections and smoothing to account for natural fluctuations. Jones used information from the US Naval Observatory and international Earth rotation services. Atomic clocks track the numbers, and the tools measure what's called 'Length of Day,' or LOD. That's the time it takes Earth to rotate once, down to the millisecond. Even tiny changes in day length matter. GPS, phone networks, and financial systems rely on split-second accuracy. A shift of just a few milliseconds can cause tech glitches. Right now, the world keeps time using Coordinated Universal Time, or UTC. Sometimes we add a leap second to stay in sync with Earth's slow shifts. If the Earth keeps rotating faster, experts may have to remove a second, called a negative leap second. It's never happened before. The long-term trend is more familiar. Billions of years ago, Earth spun so fast that a day lasted only a few hours. It happened due to the moon's gravitational pull. Now, something inside Earth may be speeding it back up. But researchers say current models of the atmosphere and oceans don't explain what's happening. 'Sooner or later, Earth will decelerate,' Zotov said. But for now, the spin continues to speed up.
Yahoo
5 days ago
- Science
- Yahoo
Earth's Rotation Is Speeding up This Summer—but Just for 3 Days
Here's what you'll learn when you read this story: Although the Earth completes one full rotation in 86,400 seconds on average, that spin fluctuates by a millisecond or two every day. Before 2020, the Earth never experienced a day shorter than the average by much more than a millisecond, but in the past five years, it's been more likely to see days during the summer than are nearly half-a-millisecond shorter than pre-2020s levels. In 2025, the Earth will continue this trend, and scientists predict that three days—July 9, July 22, and August 5—could be atypically short compared to historical averages. While many of the astronomical truths of existence feel like immutable facts compared to our relatively puny lifespans, the movement of the heavens is constantly changing and evolving. Take the Earth's rotation, for example. During the Mesozoic, dinosaurs actually experienced 23 hours days, and as early as the Bronze Age, the average day was 0.47 seconds shorter. 200 million years from now, a standard Earth day will actually be 25 hours long (and it remains to be seen whether or not humans will still complain about there not being enough hours in the day). While the Earth's rotation changes over cosmic timescales, it also fluctuates on daily ones. We all know that a day lasts 24 hours, or 86,400 seconds, but that's not perfectly accurate. Earthquakes, volcanoes, tidal forces, subterranean geology, and many other mechanisms can cause the planet's rotation to slow down or speed up, and those micro-adjustments can trend over time. Although Earth's overall rotational trend is to slow down, since 2020, scientists have noticed—thanks to the International Earth Rotation and Reference Systems Service (IERS) at the U.S. Naval Observatory in Washington D.C.—that Earth's rotation is speeding up. So much so, in fact, that experts expect we'll need to subtract a leap second for the first time ever in 2029. A new report from claims that this fast-rotating trend won't be slowing down in 2025, either. According to IERS data, the three shortest days (mathematically speaking) this year will be July 9, July 22, and August 5. These are the dates when the Moon will be furthest from the equator, which will impact the speed of Earth's rotation. Current predictions place the shortest day, August 5, at roughly 1.51 milliseconds shorter than average. That doesn't quite beat out the recent record holder—July 5, 2024, which clocked in at 1.66 milliseconds shorter than average—but it's still a full half-millisecond faster than when this rotational trend began in 2020 (and, technically, it could still break the record once scientists measure the actual rotation on the day). 'Nobody expected this,' Leonid Zotov, an Earth rotation expert from Moscow State University, told Zotov co-authored a study in 2022 analyzing the cause of Earth's recent rotational uptick. 'The cause of this acceleration is not explained […]. Most scientists believe it is something inside the Earth. Ocean and atmospheric models don't explain this huge acceleration.' Scientists will continue to study the reasons behind the Earth's rotational fluctuation, and we'll all endure at least one leap second skip before abandoning leap seconds completely by 2035. However, Zotov also tells that this acceleration is not a new trend. In other words, we're not traveling back toward back toward the Mesozoic in terms of rotation. The planet will eventually continue its steady deceleration—this is, of course, it's natural tendency, but surface changes like polar ice melt can also contribute to the Earth's rotation slowing down. The only constant is change. You Might Also Like The Do's and Don'ts of Using Painter's Tape The Best Portable BBQ Grills for Cooking Anywhere Can a Smart Watch Prolong Your Life?
WIRED
5 days ago
- Science
- WIRED
Space Elevators Could Totally Work—If Earth Days Were Much Shorter
Jun 27, 2025 9:00 AM What would it take to run a cable from the ISS to Earth? Depends how fast you want the Earth to rotate. Illustration:Suppose you could speed up Earth's rotation so that a day was only half as long? What would happen? Well, for starters we'd have to make new clocks that only have hours 1 to 6 for am and pm. If you had tickets to an 8 o'clock concert, you'd be out of luck: 8 o'clock no longer exists. But maybe a more germane question is, why do physicists ask nutty questions like this? It's never going to happen—just move on, right? Well, here's the deal. Thinking about counterfactual scenarios gives us insight into how things work here in reality. Plus, it's fun! Need I say more? OK, it might even help us build a working space elevator. Oh, you don't know what a space elevator is? It's a sci-fi staple, a tether from Earth up to an orbiting space station in geosynchronous orbit. A cable-climbing car would ride up and down, just like a regular elevator. Basically it's a way of getting out to space as easily and routinely as you ride an elevator to your office in the morning—no rockets required. Let's start off with some basic questions and build up to some more complicated physics. What Is a Day? You can't get more basic than that. But the answer isn't simple. If you said a day is 24 hours, you're right—and wrong. If you're standing outside, the time at which the sun is at its highest point in the sky is called local noon. If you stand there until the next local noon, the amount of elapsed time is defined as 24 hours. So an hour is 1/24th of the time between two local noons. But wait! This isn't the same as a complete revolution of the Earth. If you measured the time of a complete revolution, you'd find that it's not exactly 24 hours. The reason is that the Earth is doing two things at once: It's spinning on its axis, which causes the sun to appear to move across the sky. But it's also orbiting the sun over the course of a year, which means a complete rotation will not result in the sun being in the same position in the sky. There are actually two different types of days. The solar day is the one you are thinking of, and it's the one described above. The other type is called a sidereal day . Here's a totally not-to-scale diagram that will help you understand the difference: In position 1, there is a stick marking a location. That stick is pointing toward the sun so that this would be local noon. As the Earth moves to position 2, it makes one complete rotation. However it's not yet local noon, because the relative position of the sun has changed due to the Earth's orbital motion. This is called a sidereal day. Finally, the Earth moves a little bit beyond one complete revolution, so the stick again points towards the sun for a second local noon. The sidereal day is just a little bit shorter—approximately 23 hours and 56 minutes. Why does that matter? Well, if we are going to make a day half as long, we need to decide which one to divide by 2. Just for simplicity, let's say the solar day is 12 hours instead of 24 hours, but the orbit around the sun (and the length of a year) is the same. You'd Feel Lighter at the Equator There are many things that would change with a 12-hour day. Like, how long would you sleep? Would we still work 40 hours a week? Would a week still be seven days (and still named after objects in the sky?). But let's focus on some of the physics stuff. Here's the fun part. If you stood on a scale at the north pole and then did the same thing at the equator, the scale would give a higher value at the north pole. Actually, it's true for both a 24-hour day and a 12-hour day—but it's more noticeable with a shorter day. Let's start at the north pole. Here is a force diagram for a normal human standing on a scale: There are two forces acting on the person. First, there is the downward pulling gravitational force due to the interaction with the Earth. (This is the mass, m, multiplied by the gravitational field, g.) Second, there is the upward-pushing force from the scale (we call this a normal force since it's perpendicular to the ground). The reading on the scale is actually the magnitude of the normal force and not the weight. Newton's second law states that the net force on an object is equal to the product of the mass and acceleration. For a person at the north pole, the acceleration would be zero (they are just standing there). That means that the normal force is equal in magnitude to the gravitational force. What if you are instead standing on the equator? Here's a force diagram for that. Isn't it the same except sideways? No, it's different. Notice that in this case the normal force isn't as strong as the gravitational force (the arrow is shorter). This is because a person standing at the equator is not stationary. They're moving in a circular path as the Earth rotates. When an object moves in a circle, it has an acceleration toward the center. This centripetal acceleration has a magnitude that increases with the angular velocity (ω) as well as the radius of the circular path (r). The sum of the two forces (gravity and the scale) must equal the mass multiplied by the acceleration. This means that the force of the scale will be: Why is the north pole different? Yes, you are still rotating, but you are ON the axis of rotation, so the radius (your distance from the axis) is zero, and that gives you a zero acceleration. If you use an angular velocity for a 24-hour day, your effective weight at the equator is 99.7 percent of the value at the north pole. With a 12-hour day (which means the Earth is spinning twice as fast and your angular velocity is twice as high), the scale would read a value that's 98.6 percent of the actual gravitational force. The faster you spin, the lighter you are. Would you notice that in real life? I think that if you flew straight from the north pole to the equator, you might feel a change in effective weight of over 1 percent. With this lower weight, you could jump just a little bit higher and walk around with a lighter step. Space Elevators Let's think about orbits for a moment. If you put an object near the Earth, there will be a downward-pulling gravitational force. As you get farther away from the surface of the Earth, this gravitational force gets weaker. However, if you have an object in space that's initially at rest, the gravitational force will cause it to fall down and crash. But wait! If we use the same circular motion trick for the effective weight we can make the object move in a circle such that the mass multiplied by the centripetal acceleration is equal to the gravitational force. It would be the same as standing on a scale with an effective weight of zero. We call this a circular orbit. The rate that an object orbits depends on the distance from the center of the Earth (r). We can calculate that as: Here G is the universal gravitational constant and M is the mass of the Earth. If you put in a value of r that is 400 kilometers above the surface of the Earth, you get an angular velocity that would take the object 92 minutes to complete an orbit. Note: This is pretty much what the international space station (ISS) does. Wouldn't it be cool if the International Space System had a cable running down to the Earth? Unfortunately, the dangling cable would be whipping around the Earth so fast, you wouldn't be able to embark or disembark. Well, it's possible to fix this problem. Suppose you move the space station up to a distance of 36,000 kilometers instead of 400 kilometers? In that case, the angular velocity of the ISS would be the same as the rotation rate of the Earth. As seen from the surface of the Earth, the ISS would remain in the same spot in the sky because they would both take 24 hours to rotate. We call this a geostationary orbit—but it has to be directly over the equator so that the direction of the rotations are the same. With an object in geostationary orbit, you could run a cable down to the Earth. Boom —there's your space elevator. But wait! There are some problems. Can you imagine a cable that's 36,000 kilometers long? That's a LOT of cable. It's so much that you'd also have to counterbalance the weight of the cable with some big mass a little past the geostationary level. This system would require a tension in the material that exceeds the maximum value for the strongest steel cables. It could only work with something like a carbon nanotube cable—which we don't have (yet). OK, but what if we make the Earth spin twice as fast with a 12-hour day? In that case, a geostationary orbit would have a larger angular velocity (to match the faster Earth). If you crunch the numbers, the geostationary distance would be only 20,000 kilometers, or around 45 percent shorter. What if the Earth rotated so fast that the ISS was in a geostationary orbit just 400 kilometers above the surface? That might make the space elevator possible. Of course now we are going to have a MUCH shorter day of only 92 minutes. That's not worth it. Can you imagine having to get out bed every 92 minutes? I might even get dizzy. It's too bad because I really want a space elevator.
Yahoo
7 days ago
- Science
- Yahoo
The shortest day of your life could be this summer – here's when
If you purchase an independently reviewed product or service through a link on our website, BGR may receive an affiliate commission. We could soon be living through the shortest day of our lives. According to reports, Earth is continuingly spinning faster on its axis. While we've known about this phenomenon for a few years now, scientists are paying close attention to the length of the days this summer. According to a report from Time and Date, July 9, July 22, or August 5 could be the shortest days in recent years. We know for a fact that Earth's rotational speed has been increasing since at least 2020. And each year, we see slightly shorter days during the middle of the year. Today's Top Deals Best deals: Tech, laptops, TVs, and more sales Best Ring Video Doorbell deals Memorial Day security camera deals: Reolink's unbeatable sale has prices from $29.98 Now, it's worth noting that the shortest day of our lives won't be noticeably shorter in the grand scheme of things. In fact, the difference in the Earth's rotational speed that day won't even be noticeable, except when looking at it through the perspective of the atomic clock. That's because while technically shorter, the day will only be around 1.51 milliseconds shorter, at most. Exactly why the Earth's rotation has accelerated is unclear, but scientists believe it could have a lasting impact. Not only will it shorten our days, but that can also affect a slew of other things, like the global climate and more. While we don't know the exact reason why, we do know that tidal forces from the Moon and Sun contribute to the Earth's rotation. However, the list of things that can affect the speed of the Earth's rotation, and thus the length of the day, is longer than you'd expect. Most believe that the change is driven by forces within the Earth, but it's impossible to completely rule out atmospheric conditions, too. Still, knowing when the shortest day of our lives will occur is important information if we want to stay up to date with how the Earth is doing as a whole. It's no secret that the Earth will one day be swallowed up by the Sun. However, until that happens, the Earth will continue to survive as it has for billions of years. And as it survives, the rotational speed that drives our days will shorten and even increase as the forces affecting it change and evolve. While we don't know which of the three days listed above will turn out to be the shortest day of our lives, we know it's very likely to happen again, at least until the Earth slows down. More Top Deals Amazon gift card deals, offers & coupons 2025: Get $2,000+ free See the
Forbes
20-06-2025
- Science
- Forbes
Get Ready For The Shortest Day Since Records Began As Earth Spins Faster
Earth could be about to record its fastest-ever rotation. Since 2020, Earth has been rotating faster than at any point since records began in 1973, with each successive year producing the shortest day. Last year, the shortest day was recorded on July 5, and Earth is expected to get close to this again on or close to July 9, July 22 and August 5, according to "Rapidly spinning globe. Symbolic of time passing, travel and other metaphors of space and time." Earth takes a nominal 24 hours to rotate once on its access, which is equal to 86,400 seconds. Until 2020, Earth's rotation had been gradually slowing down, and the shortest ever day recorded was just 1.05 milliseconds under 86,400 seconds. However, on July 19, 2020, Earth rotated 1.47 milliseconds less than 86,400 seconds. Last year, on July 5, it was even shorter at 1.66 milliseconds. Since 2020, Earth has seen 28 of its fastest days and predictions from International Earth Rotation and Reference Systems Service and U.S. Naval Observatory indicate that Earth will again rotate faster on July 9, July 22 or August 5. The uncertainty comes from the exact position of the moon, which acts as a drag factor, particularly when it's close to the equator. In the long-term, the moon is gradually slowing down the Earth's rotation, its gravitational pull causing tides and making Earth's orbital path around the sun slightly elliptical. Precise measurements of the length of a day come from atomic clocks and monitoring by the IERS. Scientists do not know why Earth's rotation has been speeding up since 2020. various factors are likely at play, including the motion of Earth's core and mantle, a shifting of mass due to the melting of ice sheets and glaciers, and variations in ocean currents and air movement. All of these could influence the day length by milliseconds. It could also be down to the 'Chandler wobble' — the movement of Earth's geographical poles across its surface. Historically, international timekeepers have added leap seconds to keep atomic time aligned with Earth's spin. However, since Earth is now rotating faster, not slower, so leap seconds are redundant. Instead, negative leap seconds— i.e., removing a second) — are being considered. IERS confirmed earlier this month that no leap second would be added in 2025. The last leap second was positive and used at the end of December 2016. Scientists are unsure what to do because the current speeding-up may be a blip in a longer trend of Earth's rotation slowing. It may seem trivial, but the fact that Earth is spinning faster in 2025, shaving milliseconds off the day, is critical for maintaining time accuracy worldwide. Maintaining alignment between Earth time and atomic time is crucial for GPS and satellite navigation, financial systems reliant on precise timestamps and synchronizing networks across the world.
