- City Council approves 5-year permit for MSG, shortest extension in venue’s history Gothamist
- Madison Square Garden gets 5-year extension amid push for Penn Station improvements Newsday
- City Council unanimously approves 5-year permit for Madison Square Garden Crain’s New York Business
- NYC officials set to give James Dolan five-year permit for Madison Square Garden — but battle over site is brewing New York Post
- City Council grants Madison Square Garden shortest operating permit ever in final vote New York Daily News
- View Full Coverage on Google News
Tag Archives: shortest
Astronomers spot a pair of stars with shortest orbit detected to date
Astronomers have discovered a pair of stars with such a short orbit they appear to circle each other in just 51 minutes.
The system seems to be one of a rare class of binaries known as a ‘cataclysmic variable,’ in which a star similar to our sun orbits tightly around a white dwarf — a hot, dense core of a burned-out star.
A cataclysmic variable occurs when the two stars draw close, over billions of years, causing the white dwarf to start accreting, or eating material away from its partner star.
This process can give off enormous, variable flashes of light that, centuries ago, astronomers assumed to be a result of some unknown cataclysm.
The ‘cataclysmic’ system, which resides about 3,000 light years from Earth in the Hercules constellation, has the shortest orbit detected to date of its type.
It was discovered by astronomers at MIT and has been named ZTF J1813+4251.
Astronomers have discovered a pair of stars with such a short orbit they appear to circle each other in just 51 minutes. The system is known as a cataclysmic variable, which occurs when two stars draw close, over billions of years, causing the white dwarf to start accreting, or eating material away from its partner star (as depicted above)
Unlike other such systems observed in the past, experts caught this cataclysmic variable as the stars eclipsed each other multiple times, allowing the team to precisely measure the properties of each star.
They then ran simulations of what the system is likely doing today and how it should evolve over the next hundreds of millions of years.
This led the researchers to theorise that the stars are currently in transition, and that the sun-like star has been circling and ‘donating’ much of its hydrogen atmosphere to the voracious white dwarf.
As time goes on, the astronomers say the sun-like star will eventually be stripped down to a mostly dense, helium-rich core.
In another 70 million years, the stars will then migrate even closer together, with an ultrashort orbit reaching just 18 minutes, before they begin to expand and drift apart.
Decades ago, researchers at MIT and elsewhere predicted that such cataclysmic variables should transition to ultrashort orbits — but is the first time such a transitioning system has been directly observed.
‘This is a rare case where we caught one of these systems in the act of switching from hydrogen to helium accretion,’ said Kevin Burdge, from MIT’s Department of Physics.
‘People predicted these objects should transition to ultrashort orbits, and it was debated for a long time whether they could get short enough to emit detectable gravitational waves. This discovery puts that to rest.’
Burdge and colleagues discovered the new system within a vast catalogue of stars, observed by the Zwicky Transient Facility (ZTF), a survey that uses a camera attached to a telescope at the Palomar Observatory in California to take high-resolution pictures of wide swaths of the sky.
The survey has taken more than 1,000 images of each of the more than 1 billion stars in the sky, recording each star’s changing brightness over days, months, and years.
Burdge combed through the catalogue, looking for signals of systems with ultrashort orbits, the dynamics of which can be so extreme that they should give off dramatic bursts of light and emit gravitational waves.
These appeared to flash repeatedly, with a period of less than an hour — a frequency that typically signals a system of at least two closely orbiting objects, with one crossing the other and briefly blocking its light.
The discovery was made by the Zwicky Transient Facility (ZTF), which operates at Caltech’s Palomar Observatory, with the help of the W. M. Keck Observatory in Hawaii (pictured)
Burdge used an algorithm to weed through over 1 billion stars, each of which was recorded in more than 1,000 images, an ultimately zeroed in on ZTF J1813+4251.
‘This thing popped up, where I saw an eclipse happening every 51 minutes, and I said, ok, this is definitely a binary,’ Burdge said.
He and his colleagues further focused on the system using the W.M. Keck Observatory in Hawaii and the Gran Telescopio Canarias in Spain.
They found that the first object was likely a white dwarf, at 1/100th the size of the sun and about half its mass.
The second was a sun-like star near the end of its life, at a tenth the size and mass of the sun (about the size of Jupiter).
However, something didn’t quite add up.
‘This one star looked like the sun, but the sun can’t fit into an orbit shorter than eight hours — what’s up here?’ Burdge said.
He realised that ZTF J1813+4251 was likely a cataclysmic variable — a discovery that means it is the shortest orbit cataclysmic variable detected to date.
‘This is a special system,’ Burdge added. ‘We got doubly lucky to find a system that answers a big open question, and is one of the most beautifully behaved cataclysmic variables known.’
The discovery has been published in the journal Nature.
Earth broke the record for the shortest day since atomic clocks were invented
Earth completed its normal 24-hour rotation 1.59 milliseconds fast on June 29, breaking the record for the shortest day in modern history. (NASA)
Estimated read time: 4-5 minutes
ATLANTA — If you feel like there’s less time in the day, you’re correct.
Scientists recorded the shortest day on Earth since the invention of the atomic clock.
Our planet’s rotation measured in at 1.59 milliseconds short of the normal 24-hour day on June 29, according to the International Earth Rotation and Reference Systems Service, an organization in charge of global timekeeping.
A rotation is the length of time the Earth takes to spin once on its axis, which is roughly 86,400 seconds.
The previous record was documented on July 19, 2020, when the day measured 1.47 milliseconds shorter than normal.
The atomic clock is a standardized unit of measurement that has been used since the 1950s to tell time and measure the Earth’s rotation, said Dennis McCarthy, retired director of time at the U.S. Naval Observatory.
Despite June 29 breaking a record for the shortest day in modern history, there have been much shorter days on Earth, he said.
When dinosaurs still roamed the planet 70 million years ago, a single day on Earth lasted about 23½ hours, according to a 2020 study published in Paleoceanography and Paleoclimatology.
Since 1820, scientists documented Earth’s rotation slowing down, according to NASA. In the past few years, it began speeding up, McCarthy said.
Why is the speed increasing?
Researchers do not have a definitive answer on how or why Earth is turning slightly faster, but it may be due to glacial isostatic adjustment, or the movement of land due to melting glaciers, McCarthy said.
Earth is slightly wider than it is tall, which makes it an oblate spheroid, he said. The glaciers at the poles weigh down on the Earth’s crust at the North and South poles, McCarthy said.
Since the poles are melting due to the climate crisis, there is less pressure on the top and bottom of the planet, which moves the crust up and makes the Earth rounder, he said. The circular shape helps the planet spin faster, McCarthy said.
It’s the same phenomenon that figure skaters use to increase and decrease their speed, he said.
When skaters stretch their arms away from their body as they spin, it takes more force for them to rotate, he said. When they tuck their arms close to their body, their speed increases because their body mass is closer to their center of gravity, McCarthy said.
As Earth becomes rounder, its mass becomes closer to its center, which increases its rotational speed, he said.
Our day-to-day existence doesn’t even recognize that millisecond.
–Dennis McCarthy, retired director of time at the U.S. Naval Observatory
Some have suggested a correlation with the Chandler wobble, McCarthy said. The axis our planet rotates on is not lined up with its axis of symmetry, an invisible vertical line that divides the Earth into two equal halves.
This creates a slight wobble as the Earth rotates, similar to how a football wobbles when it is thrown, he said.
When a player tosses a football, it wobbles slightly as it rotates since it often doesn’t spin around the axis of symmetry, he said.
“If you’re a really good passer in football, you line up the axis of rotation with the axis of symmetry of the football, and it doesn’t wobble,” McCarthy said.
However, McCarthy said the Chandler wobble likely does not affect the rotational speed of Earth because the wobble is due to the planet’s shape. If the planet’s shape changes, it changes the frequency of the wobble, not its rotation frequency, he said.
Removing a leap second
Since researchers began measuring the Earth’s rotational speed using atomic clocks, Earth had been slowing down its rotational speed, McCarthy said.
“Our day-to-day existence doesn’t even recognize that millisecond,” McCarthy said. “But if these things add up, then it could change the rate at which we insert a leap second.”
In the instances when the milliseconds build up over time, the scientific community has added a leap second to the clock to slow down our time to match Earth’s, he said. There have been 27 leap seconds added since 1972, according to EarthSky.
Because Earth is now rotating faster, a leap second would need to be taken away to catch our timekeeping up with Earth’s increasing rotational speed, McCarthy said.
If the planet continues this rotational trend, the removal of a leap second likely wouldn’t need to happen for another three to four years, he said.
×
Most recent Science stories
More stories you may be interested in
Earth had shortest day since atomic clock was invented
Scientists recorded the shortest day on Earth since the invention of the atomic clock.
A rotation is the length of time the Earth takes to spin once on its axis, which is roughly 84,600 seconds.
The previous record was documented on July 19, 2020, when the day measured 1.47 milliseconds shorter than normal.
The atomic clock is a standardized unit of measurement that has been used since the 1950s to tell time and measure the Earth’s rotation, said Dennis McCarthy, retired director of time at the US Naval Observatory.
Despite June 29 breaking a record for the shortest day in modern history, there have been much shorter days on Earth, he said.
When dinosaurs still roamed the planet 70 million years ago, a single day on Earth lasted about 23 1/2 hours, according to a 2020 study published in Paleoceanography and Paleoclimatology.
Since 1820, scientists documented Earth’s rotation slowing down, according to NASA. In the past few years, it began speeding up, McCarthy said.
Why is the speed increasing?
Researchers do not have a definitive answer on how or why Earth is turning slightly faster, but it may be due to glacial isostatic adjustment, or the movement of land due to melting glaciers, McCarthy said.
Earth is slightly wider than it is tall, which makes it an oblate spheroid, he said. The glaciers at the poles weigh down on the Earth’s crust at the North and South poles, McCarthy said.
Since the poles are melting due to the climate crisis, there is less pressure on the top and bottom of the planet, which moves the crust up and makes the Earth rounder, he said. The circular shape helps the planet spin faster, McCarthy said.
It’s the same phenomenon that figure skaters use to increase and decrease their speed, he said.
When skaters stretch their arms away from their body as they spin, it takes more force for them to rotate, he said. When they tuck their arms close to their body, their speed increases because their body mass is closer to their center of gravity, McCarthy said.
As Earth becomes rounder, its mass becomes closer to its center, which increases its rotational speed, he said.
Some have suggested a correlation with the Chandler wobble, McCarthy said. The axis our planet rotates on is not lined up with its axis of symmetry, an invisible vertical line that divides the Earth into two equal halves.
This creates a slight wobble as the Earth rotates, similar to how a football wobbles when it is thrown, he said.
When a player tosses a football, it wobbles slightly as it rotates since it often doesn’t spin around the axis of symmetry, he said.
“If you’re a really good passer in football, you line up the axis of rotation with the axis of symmetry of the football, and it doesn’t wobble,” McCarthy said.
However, McCarthy said the Chandler wobble likely does not affect the rotational speed of Earth because the wobble is due to the planet’s shape. If the planet’s shape changes, it changes the frequency of the wobble, not its rotation frequency, he said.
Removing a leap second
Since researchers began measuring the Earth’s rotational speed using atomic clocks, Earth had been slowing down its rotational speed, McCarthy said.
“Our day-to-day existence doesn’t even recognize that millisecond,” McCarthy said. “But if these things add up, then it could change the rate at which we insert a leap second.”
In the instances when the milliseconds build up over time, the scientific community has added a leap second to the clock to slow down our time to match Earth’s, he said. There have been 27 leap seconds added since 1972, according to EarthSky.
Because Earth is now rotating faster, a leap second would need to be taken away to catch our timekeeping up with Earth’s increasing rotational speed, McCarthy said.
If the planet continues this rotational trend, the removal of a leap second likely wouldn’t need to happen for another three to four years, he said.
Earth is spinning faster than usual and had its shortest day ever
The Earth is spinning faster, and recently recorded its shortest day ever, scientists say. June 29, 2022 was 1.59 millisecond less than the average day, scientist Leonid Zotov told CBS News.
The normal length of day is 24 hours, or 86,400 seconds. But in recent years, the Earth’s rotation has accelerated, shortening some days by milliseconds. “Since 2016 the Earth started to accelerate,” said Zotov, who works at works for Lomonosov Moscow State University and recently published a study on what might cause the changes in Earth’s rotation. “This year it rotates quicker than in 2021 and 2020.”
Zotov and his colleagues believe the fluctuation could be caused by the Earth’s tides.
He says not every day is shorter, but if the trend continues, atomic time – the universal way time is measured on Earth – may have to change. Some scientists propose introducing a negative leap second. “Since we can not change the clock arrows attached to the Earth rotation, we adjust the atomic clock scale,” he said.
As opposed to leap years, which have an extra day added, a negative leap second would mean clocks skip one second.
Some engineers oppose the introduction of a leap second, as it could lead to large-scale and devastating tech issues. Meta engineers Oleg Obleukhov and Ahmad Byagowi, who is also a researcher, wrote blog post about it for Meta, which is supporting an industry-wide effort to stop future introductions of leap seconds.
“Negative leap second handling is supported for a long time and companies like Meta often run simulations of this event,” they told CBS News. “However, it has never been verified on a large scale and will likely lead to unpredictable and devastating outages across the world.”
The concept, which was introduced in 1972, “mainly benefits scientists and astronomers as it allows them to observe celestial bodies using UTC [Coordinated Universal Time] for most purposes,” they wrote in the blog post.
“Introducing new leap seconds is a risky practice that does more harm than good, and we believe it is time to introduce new technologies to replace it,” they write.
While positive leap seconds could cause a time jump, resulting in IT programs crashing or even data being corrupted, a negative leap second would be worse, they argue.
“The impact of a negative leap second has never been tested on a large scale; it could have a devastating effect on the software relying on timers or schedulers,” they write. “In any case, every leap second is a major source of pain for people who manage hardware infrastructures.”
The pair believes one of many contributing factors to Earth’s faster spin could be the constant melting and refreezing of ice caps on the world’s tallest mountains.
“It is all about the law of conservation of momentum that applies to our planet Earth. Every atom on the planet contributes to the momentum of the earth’s angular velocity based on the distance to the rotation axis of the earth,” Obleukhov and Byagowi told CBS News. “So, once things move around, the angular velocity of the earth can vary.”
“This phenomenon can be simply visualized by thinking about a spinning figure skater, who manages angular velocity by controlling their arms and hands,” they said. “As they spread their arms the angular velocity decreases, preserving the skater’s momentum. As soon as the skater tucks their arms back in, the angular velocity increases. Same happens here at this moment because of rising temperatures on Earth. Ice caps melt and lead to angular velocity increase.”
Zotov and his colleagues Christian Bizouard and Nikolay Sidorenkov will present their research at this month’s Asia Oceania Geosciences Society conference for geosciences, according to Timeanddate.com, which first reported on Earth’s faster spin and shorter days.
Earth Just Set a New Record For Its Shortest Day In Recorded History
Since the 1960s, scientists have used atomic clocks to precisely monitor time. However, on June 29, scientists watching these clocks noticed an anomaly: it was Earth’s shortest day in recorded history.
According to a report by timeanddate, on June 29, Earth completed a rotation in 1.59 milliseconds less than 24 hours, highlighting a recent trend that has seen the planet’s rotation speed up. In 2020, the Earth achieved its 28 shortest days since daily measurements began.