At the start of peak Atlantic hurricane season, conditions in the Atlantic basin continue to indicate that this year’s will be an “above normal” one, federal scientists said Thursday. If those predictions play out, this will be the seventh consecutive year with an above-normal season.
The forecast indicates there could be 14 to 20 named storms, with six to 10 turning into hurricanes that sustain winds of at least 74 miles per hour, said Matthew Rosencrans, lead hurricane forecaster at the National Oceanic and Atmospheric Administration. Three to five of those could become major hurricanes, which have winds of 111 miles per hour or greater, corresponding to Categories 3, 4 and 5 on the Saffir-Simpson scale.
The updated forecast calculates a 60 percent chance of an above-normal season, down slightly from the preseason forecast in May.
The announcement follows a relatively quiet start to hurricane season, with no major storm developing in the Atlantic Ocean. All three of the named storms this year have been “shorties,” or short-lived storms that last less than 48 hours and have minimal impacts.
However, it’s not unusual for storms to ramp up later in the summer, after ocean waters have warmed more and can fuel large, swirling storms. The Atlantic hurricane season officially runs from June 1 to Nov. 30, though it peaks between mid-August and October, when 90 percent of tropical storm activity usually occurs.
Thursday’s forecast was in part informed by a climatic pattern called La Niña, which has been in place intermittently since 2020 and impacts various aspects of weather, including prolonging the drought in the Western United States. La Niña conditions can “enhance Atlantic hurricane activity,” Mr. Rosencrans said, in part because of changes in wind direction and speed.
Scientists have documented a number of ways that climate change is altering cyclonic storms, making them more powerful and more destructive. Hurricanes are unleashing higher amounts of rainfall, which can worsen flooding. And because warmer water fuels hurricanes, the zone in which these storms can form is also expanding out of the tropics and toward subtropics and the middle latitudes.
“It only takes one landfalling storm to devastate a community,” Mr. Rosencrans said, referring to when a storm’s eye crosses the shoreline. “Now is the time to know your risks, develop a plan and be prepared for potential tropical storms or hurricanes ahead.”
Tropical coastal ecosystems are among the most biodiverse areas on Earth. And they're also on the front lines of effects caused by human activity. That's why it's becoming increasingly important, especially as human populations increase, to manage the impacts of runoff and wastewater that flow into the sea.
"Tropical coastal ecosystems, such as coral reefs, are oligotrophic, meaning they are located in nutrient-poor waters and have therefore adapted to these conditions," said Madeline Berger, a researcher at UC Santa Barbara's National Center for Ecological Analysis & Synthesis (NCEAS). "An increased influx of nutrients can therefore disrupt ecosystem functioning."
In a paper that appears in the journal Ocean and Coastal Management, lead author Berger and her colleagues tackle the issue of nutrient pollution through a case study in coastal Central America. The result? Agricultural operations are responsible for the vast majority of nitrogen pollution that flows into the Mesoamerican Reef Region. Knowing where the pollution comes from, the researchers say, will help managers tailor solutions for mitigation.
"Our study highlights that different management strategies will need to be employed in different watersheds to help reduce nutrient input that can have detrimental impacts on coral reef and seagrass health in this area," Berger said.
The Mesoamerican Reef (MAR) is the largest barrier reef in the western hemisphere, second only to Australia's Great Barrier Reef in terms of size. Shared by Mexico, Belize, Guatemala and Honduras, it stretches for almost 700 miles and hosts a variety of creatures, including hundreds of fish species, critically endangered marine turtles, as well as mollusks, marine mammals and shorebirds. These habitats and communities, in turn, sustain local fishing as well as tourism. Millions of people flock each year to resorts and ports in Cancun, Cozumel, Belize City and other points along the coast on their Caribbean vacations.
But the reef is also in trouble. More than half of it is in poor condition due to various threats that include ocean warming, unsustainable fishing and pollution.
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"Nutrient pollution is a known threat to coral reef and seagrass," Berger said. Too much nitrogen, a common pollutant, results in a chain of events that results in oxygen-free "dead zones," and acidic conditions that can severely weaken or kill fish and other animals. Water quality issues are also among the main reasons for sindromé blanco, a pathogenic disease that leads to white lesions that spread over coral, leading to death in mere weeks. Nutrient pollution in this region, according to the researchers, "comes from four sources: agricultural production, human wastewater, atmospheric deposition and wild animal scat," with agriculture and human wastewater suspected of contributing the majority of the pollution.
To tell how much of the pollution came from upstream agriculture or human wastewater, the researchers dove into several models examining the watersheds that feed into the MAR. One was a global wastewater model that estimates the amount of nitrogen pollution based on population maps, protein consumption and known human nitrogen excretion rates, which was adapted to this specific region.
"Another group at NCEAS was also creating a spatially-explicit global model quantifying the ecological footprint of food production, so we saw an opportunity to synthesize both models to compare nutrient pollution from wastewater to nutrient pollution from crop and livestock production," Berger said.
The researchers also modelled impacts from the millions of tourists that roam up and down the coast using hotel location data, cruise ship location data and monthly statistics reported by tourism bureaus in each country. "Basically, we were trying to figure out where tourists were pooping, which turns out to be pretty tricky," she said.
The researchers found that agriculture was by far the largest contributor (92%) of nitrogen to the MAR, due to fertilizer and livestock waste runoff that make their way to the ocean via rivers and streams. Two rivers, the Rio Ulua in Honduras and Rio Motagua in Guatemala, contributed more than 50% of the modeled nitrogen pollution, collecting runoff from several upstream tributaries and draining into the ocean. Meanwhile, 90% of the modeled nitrogen pollution was attributed to 20 (out of 430) watersheds, of which 11 are located in Guatemala or Honduras. An estimated 80% of coral reefs and 68% of seagrass beds were exposed to nitrogen pollution from watershed plumes.
The results are indicative of the complexity of the pollution issue -- even land use changes and agricultural expansion very far inland can have impacts to marine ecosystems, Berger said. Additionally, the researchers found that high biodiversity habitats were more exposed to plumes originating from smaller, coastal watersheds. And while tourism represented a very small proportion of the overall pollution, the watersheds that contributed the most pollution tended to also have high number of tourists or be near those that did.
"The exercise also raised the questions of how tourists, or tourist demand, has larger impacts beyond just the physical presence of more people -- such as increased building or expanding agriculture -- that can also exacerbate pollution input," Berger said. The researchers hope that ultimately a granular approach that can be used to track the origins and paths of nitrogen and other nutrient runoff and their impacts will enable coastal managers to develop the sophisticated action plans necessary to mitigate the pollution of some of the world's most biodiverse coastal regions.
Plesiosaurs went extinct 66 million years ago, but evidence that the long-necked reptiles lived in freshwater, not just oceans, has offered hope to Nessie enthusiasts.
LONDON — Millions of years before the first (alleged) sighting of the Loch Ness monster, populations of giant reptiles swam through Jurassic seas in areas that are now Britain. Known as plesiosaurs, these long-necked creatures were thought to have dwelled exclusively in oceans.
But a discovery published in a paper last week by researchers in Britain and Morocco added weight to a hypothesis that some Loch Ness monster enthusiasts have long clung to: that plesiosaurs lived not just in seas, but in freshwater, too. That could mean, they reasoned excitedly, that Nessie, who is sometimes described as looking a lot like a plesiosaur, really could live in Loch Ness, a freshwater lake.
Local papers have celebrated the finding. It “gives further credit to the idea that Nessie may have been able to survive and even thrive in Loch Ness,” said an article on page 32 of the Inverness Courrier, a biweekly newspaper in the Scottish Highlands. “Loch Ness Monster bombshell,” blared a headline from Britain’s Daily Express tabloid. “Existence of Loch Ness Monster is ‘plausible’” read headlines in The Scotsman, The Telegraph and elsewhere, seizing on a phrase in the University of Bath’s announcement of the study’s findings.
This is not the first study to find that plesiosaurs lived in freshwater. “This new study is simply providing additional evidence for certain members of this group living in freshwater,” said Dean Lomax, a paleontologist and visiting scientist at the University of Manchester. “We’ve always known this.”
But Nick Longrich, the lead author of the study, said his team had one of the stronger cases for it because they found fossils of 12 plesiosaurs, proof that it was not just one plesiosaur that wandered into freshwater and then died there.
“The more plesiosaur fossils discovered in freshwater environments, the more this will further build the picture to explain why plesiosaurs might be turning up in freshwater environments around the world,” said Georgina Bunker, a student who was a co-author of the paper.
Dr. Longrich, a paleontologist and evolutionary biologist at the University of Bath, said it was “completely unexpected” to find the fossil of a plesiosaur that had lived in an 100-million-year-old freshwater river system that is now the Sahara.
While on a research trip to Morocco, he was sifting through a box in the back room of a shop when he spotted a “kind of chunky” bone, which turned out to be the arm of a five-foot long baby plesiosaur. Dr. Longrich paid the cashier no more than 200 Moroccan Dirham, or about $20, after bargaining to bring down the price, and brought the fossils back to Britain for further study.
Nick Longrich/University of Bath
“Once we started looking, the plesiosaur started turning up everywhere,” he said. “It reminds you there’s a lot we don’t know.” (The fossils will be returned to museums in Morocco at a later date, he said.)
As the news of the study made headlines last week, some Nessie fans were hopeful. George Edwards, who was for years the skipper of a Loch Ness tourism boat called the Nessie Hunter, said that for him the new study showed how creatures could adapt to survive in new environments — and that the world is full of mysteries. Take the coelacanth, a bony fish that was thought to have become extinct millions of years ago but was found in 1938 by a South African museum curator on a fishing trawler. “Lo and behold, they found them, alive and kicking,” Mr. Edwards said. “Anything is possible.”
Mr. Edwards said he had seen unexplained creatures in Loch Ness plenty of times: “There’s got to be a family of them.” From what he has seen, the creatures have a big arched back, no fins and are somewhat reminiscent of a plesiosaur.
But there is one detail that some Nessie lovers may have overlooked in their embrace of the plausibility of Nessie’s existence: Plesiosaurs became extinct at the same time as dinosaurs did, some 66 million of years ago. Loch Ness was only formed about 10,000 years ago, and before that it was ice.
Valentin Fischer, an associate professor of paleontology at the University of Liège in Belgium, said that it would currently be impossible for a marine reptile like the plesiosaur to live in Loch Ness.
Nick Longrich/University of Bath
The first recorded sighting of Nessie dates back to the sixth century A.D., when the Irish monk St. Columba was said to have driven a creature into the water. But global interest was revived in the 20th century, after a British surgeon, Col. Robert Wilson, took what became the most famous photo of the Loch Ness monster in 1934. Sixty years later, the photograph was revealed to be a hoax.
A famous photograph of the Loch Ness Monster taken in 1934 was later revealed to have been a hoax.Keystone/Getty Images
Steve Feltham, a full-time monster hunter who has lived on the shores of Loch Ness for three decades, said the British-Moroccan study was interesting, but that it was irrelevant to his search. Ever since it became clear that the famous 1934 photo of Nessie was fake, he has stopped believing that Nessie was a plesiosaur. Plesiosaurs have to come up for air, so he figures he would have seen it during the 12 hours a day that he scans the loch. Instead, he scans the water for giant fish that look like a boat turned upside down.
“I struggle to think of any bona fide Nessie hunter that still believes in the plesiosaur,” he said. “The hunt has moved on from that.”
The Danuri mission, lifting off on a SpaceX rocket, will help to study the moon’s magnetic field and some of its coldest and darkest places.
Joining the list of nations with ambitious plans in space, South Korea is aiming for the moon on Thursday.
Its first lunar spacecraft, named Danuri, is carrying scientific payload that will study the moon’s magnetic field, measure quantities of elements and molecules like uranium, water and helium-3, and photograph the dark craters at the poles where the sun never shines.
When is the launch, and how can I watch it?
Danuri will be carried to orbit by a SpaceX Falcon 9 rocket launching from Cape Canaveral Space Force Station in Florida. Liftoff is scheduled for 7:08 p.m. Eastern time. SpaceX will provide brief coverage of the launch beginning at 7 p.m., which you can watch in the video player embedded above. The South Korean space agency will also provide a Korean-language livestream.
Weather forecasts give an 80 percent probability of favorable conditions. If needed, SpaceX has an additional launch opportunity on Friday.
What is Danuri, and what will it study?
Originally known as the Korea Pathfinder Lunar Orbiter, the mission has now been given the name of Danuri, a portmanteau of the Korean words for “moon” and “enjoy.” It will be South Korea’s first space mission to go beyond low-Earth orbit.
Its scientific instruments include a magnetometer, a gamma-ray spectrometer and three cameras. NASA supplied one of the cameras, ShadowCam, which is sensitive enough to pick up the few photons that bounce off the terrain into the moon’s dark, permanently shadowed craters. These craters, located at the moon’s poles, remain forever cold, below minus 300 degrees Fahrenheit, and contain water ice that has accumulated over the eons.
The ice could provide a frozen history of the 4.5 billion-year the solar system and a bounty of resources for future visiting astronauts. Such ice can also be extracted and melted to provide water and broken apart into oxygen and hydrogen, which would provide both air to breathe for astronauts and rocket propellants for travelers looking to launch from the moon to other destinations.
What else has South Korea done in space?
South Korea is developing its own rockets. Its first design, Naro-1, successfully reached orbit on the third try, in 2013. Since then, the Korea Aerospace Research Institute — South Korea’s equivalent of NASA — has shifted its efforts to Nuri, a larger, three-stage rocket. The second Nuri flight in June successfully placed several satellites in orbit.
South Korea has several communications and earth observation satellites in low-Earth orbit. It also has an extensive military missile program.
How many countries have sent missions to the moon?
The United States and the Soviet Union sent numerous robotic spacecraft to the moon beginning in the 1960s. NASA’s Apollo program sent astronauts there from 1968 through 1972. The world then almost entirely lost interest in the moon for three decades, but a hubbub of activity has returned.
In the past few years, China has sent multiple successful robotic spacecraft, including three landers. NASA has sent several orbiters there and has enlisted commercial companies to send payloads to the lunar surface in the coming years.
Japan and the European Space Agency have launched moon missions, and India has sent two orbiters to the moon, although a lander accompanying the second orbiter, crashed as it descended toward the surface in 2019.
Another mission in 2019, Beresheet, a lander built by an Israeli nonprofit, SpaceIL, also crashed as it attempted to land on the moon.
“It’s not something you see every day on a sheep farm,” a farmer said of the pieces of debris that wound up in rural Australia. They are thought to be from a SpaceX spacecraft.
Mick Miners was herding sheep on a four-wheeler last week when he stumbled upon a pointy black object that looked more than nine feet tall. It reminded him of either a burned tree or a piece of farm machinery.
“Pretty frightening, actually,” Mr. Miners, 48, said by phone on Thursday from his roughly 5,000-acre property in a remote corner of southeastern Australia.
“I was quite surprised,” he added. “It’s not something you see every day on a sheep farm.”
Mr. Miners took a picture and sent it to a neighboring farmer, Jock Wallace, who happened to have discovered a similarly mysterious object on his farm a few days earlier.
It was space debris.
The U.S. space agency, NASA, said in a statement that SpaceX confirmed that the object was likely the remaining part of the jettisoned trunk segment from a Dragon spacecraft used during the Crew-1 mission’s return from the International Space Station in May last year. “If you believe you have identified a piece of debris, please do not attempt to handle or retrieve the debris,” NASA said.
Space debris refers to equipment in space that no longer works. Most space debris burns up while re-entering the atmosphere, and much of what’s left over often falls in the ocean. However, with more spaceships entering orbit — such as those from private companies like SpaceX, founded by Elon Musk — impacts on land may happen more frequently. SpaceX did not respond to a request for comment.
Jonathan McDowell, an astrophysicist at the Center for Astrophysics in Cambridge, Mass., said that it’s not unusual for space debris to be found on land after an uncontrolled re-entry.
“It was a bit surprising to me that so much of the trunk survived the heating process of re-entry,” Dr. McDowell said, but he added that there was no indication that there was anything particularly risky about the trunk. He said that in the new commercial era for space exploration, it has been much harder to get technical information from private companies to assess risk. With more information, “we could have a better assessment of, ‘Did we just get really unlucky, or should we expect this from all the trunk re-entries if they happen over land?’”
The trunk segment, which is used to carry cargo and also includes the spacecraft’s solar arrays and radiators, is jettisoned from the body of the capsule shortly after the burn is completed when it goes out of orbit. “It typically burns up in the atmosphere over the open ocean, posing minimal risk to public safety,” the Federal Aviation Administration said in a statement.
NASA said that SpaceX confirmed that the object that landed in Dalgety, Australia, was likely Dragon hardware from the jettisoned trunk segment of its Crew-1 spacecraft.Brad Tucker via Reuters
Last week, after debris from a large Chinese rocket re-entered Earth’s atmosphere over the Indian Ocean, the administrator of NASA, Bill Nelson, issued a rebuke, saying that China “did not share specific trajectory information as their Long March 5B rocket fell back to Earth.” He added that all countries should “share this type of information in advance to allow reliable predictions of potential debris impact risk, especially for heavy-lift vehicles, like the Long March 5B, which carry a significant risk of loss of life and property.”
The possibility that debris from the rocket could have struck a populated area led people around the world to track its trajectory for days. This was the third flight of Long March 5B, China’s largest rocket, which made what is called “uncontrolled re-entry” back to Earth.
The rural area of Australia where Mr. Miners discovered the space debris on July 25 lies about 100 miles south of the capital, Canberra.
Ron Lane, who owns a restaurant in the town of Dalgety, said that most people in the area — with the notable exception of himself — were not especially worried about additional space debris potentially landing on them or their homes.
“If there’s three we know about, there could be another 10 we don’t know about,” Mr. Lane said by phone from his restaurant, Tuscany In Dalgety.
Mr. Miners, who was born on the farm where he discovered the unidentified debris, said that his neighbor, Mr. Wallace, had called the authorities to report the other debris that he had found on his own property earlier in July. Public interest grew, Mr. Miners said, after Mr. Wallace called the Australian national broadcaster, which later reported on the farmers’ discoveries and said that three pieces of debris had been found.
“Then everybody found out, and I’ve had about 300 calls,” said Mr. Miners, who has about 5,500 sheep, 100 cattle and 30 horses on his farm in the district of Numbla Vale.
His own piece of debris is almost 10 feet tall by 1.3 feet, he said, and an official from the Australian Space Agency called on Thursday to say that its experts planned to visit his property next week to “have a look at it.”
Mr. Miners said he had so far enjoyed learning the preliminary details about how the debris had landed and that he was not sure what would happen next.
He said he would be “happy to keep it” but was also interested in “a bit of compensation,” if the space agencies or company wanted it back.
Sa’id Mosteshar, a professor of international space law and the director of the London Institute of Space Policy and Law, said that a person would be able to claim compensation only if the debris harmed him or her or caused any damage to his or her property.
“My guess is they’ll want it back,” Mr. Miner added. “I don’t know. I don’t know anything about it. As I said, I’m a sheep farmer.”
The Arizona Democrat had been her party’s last remaining holdout on the package, now slated to move forward on Saturday and pass the Senate within days.
WASHINGTON — Senator Kyrsten Sinema, Democrat of Arizona, announced on Thursday evening that she would support moving forward with her party’s climate, tax and health care package, clearing the way for a major piece of President Biden’s domestic agenda to move through the Senate in the coming days.
To win Ms. Sinema’s support, Democratic leaders agreed to drop a $14 billion tax increase on some wealthy hedge fund managers and private equity executives that she had opposed, change the structure of a 15 percent minimum tax on corporations, and include drought money to benefit Arizona.
Ms. Sinema said she was ready to move forward with the package, provided that the Senate’s top rules official signed off on it.
Ms. Sinema had been the final holdout on the package after Senator Joe Manchin III, Democrat of West Virginia, struck a deal with top Democrats last week that resurrected a plan that had appeared to have collapsed.
It brought Democrats one step closer to enacting the package and salvaging key pieces of their domestic agenda, beginning with a series of votes this weekend. It came just over a week after Mr. Manchin and Senator Chuck Schumer of New York, the majority leader, stunned their colleagues with an agreement to include hundreds of billions of dollars for climate and energy programs and tax increases in the legislation, on top of a proposal to reduce the price of prescription drugs and extend expanded health insurance subsidies.
With Republicans united in opposition, the measure needs the unanimous support of Democrats to move forward in the 50-50 Senate, so the party cannot afford even one defection.
Mr. Schumer confirmed in a statement that he had reached an agreement “that I believe will receive the support of the entire Senate Democratic conference.” He said the revised legislation would be released on Saturday.
“The agreement preserves the major components of theInflation Reduction Act, including reducing prescription drug costs, fighting climate change, closing tax loopholes exploited by big corporations and the wealthy, and reducing the deficit,” he said. The deal will “put us one step closer to enacting this historic legislation into law.”
Mr. Biden called on the Senate to quickly pass the measure, praising the deal as “another critical step toward reducing inflation and the cost of living for America’s families.”
Ms. Sinema insisted on the removal of a provision that would have limited the preferential tax treatment of income earned by some wealthy hedge fund managers and private equity executives. Democrats instead added a new 1 percent excise tax that companies would have to pay on the amount of stock that they repurchase, said one Democratic official, who disclosed details of the plan on the condition of anonymity.
That provision, the official said, would ensure that the package still reduces the federal deficit by as much as $300 billion, the same amount Democrats aimed for with the original deal and a key priority for Mr. Manchin.
Democrats also agreed to a request by Ms. Sinema to include billions of dollars to combat droughts, according to officials briefed on the emerging plan, something that is crucial to Arizona as it suffers from a devastating megadrought. They were expected to restructure the 15 percent minimum tax on corporations to make it less burdensome on manufacturers. Earlier this week, business leaders in Arizona appealed directly to Ms. Sinema to simplify that proposal, which was included in part because she had resisted increasing tax rates as part of the plan.
“Manufacturers remain concerned that this bill will stifle new cures and therapies,” Jay Timmons, the president and chief executive of the National Association of Manufacturers, said on Twitter, even while praising the removal of certain tax provisions. He added, “We remain skeptical and will be reviewing the revised legislation carefully.”
While most Democrats had been quick to rally around the deal Mr. Manchin reached with Mr. Schumer when it was announced last week, Ms. Sinema had refused to weigh in and privately signaled that changes, particularly to the tax proposals, would be needed to win her vote.
Even as she wrangled an unusually bipartisan vote margin on Thursday for a judge she supported for the U.S. Court of Appeals for the Ninth Circuit — securing the support of nearly 20 Republicans — Ms. Sinema was being lobbied by both sides of the aisle. She and Mr. Manchin huddled in the chamber at one point, speaking in hushed voices.
Ms. Sinema, an enigmatic centrist, had already forced her party to abandon their plans to overhaul much of the tax code, and her characteristic silence frustrated Democrats eager to take up the bill. After hearing that she had given the bill her support, several Democratic senators and aides celebrated, confident that final passage was within reach.
“We are about to pass monumentally necessary and popular legislation,” declared Senator Brian Schatz, Democrat of Hawaii, adding, “It’s happening.”
Mr. Schumer said that he planned to hold a test vote on the measure on Saturday afternoon, keeping the Senate from leaving for a planned five-week August recess to finish work on the legislation.
The package still must clear a series of hurdles before the Senate can pass it. Because Democrats are using the arcane budget reconciliation process to protect the measure from a filibuster, it must be blessed by the Senate parliamentarian to ensure that its elements adhere to the strict rules that govern the process. That process was expected to continue on Friday, and could result in further changes to the measure if certain pieces are deemed out of order.
Ms. Sinema left herself room to change course should those changes raise any concerns, saying she would move forward with the bill “subject to the parliamentarian’s review.”
Republicans will have an opportunity this weekend to try to force changes before final passage of the legislation during a marathon series of amendment votes known as a vote-a-rama. If all Republicans are present, all 50 senators who caucus with Democrats must remain united to protect the legislation as written.
In her statement, Ms. Sinema said she would work with Senator Mark Warner, Democrat of Virginia, on separate legislation to address the preferential tax treatment for hedge fund income, sometimes called the carried interest loophole. She said they would focus on “protecting investments in America’s economy and encouraging continued growth while closing the most egregious loopholes that some abuse to avoid paying taxes.”
But doing so outside of a reconciliation bill would require 60 votes to overcome an all-but-certain Republican filibuster, and it is unlikely that enough G.O.P. senators would join the effort to allow that to happen.
The following is an extract from our Lost in Space-Time newsletter. Each month, we hand over the keyboard to a physicist or two to tell you about fascinating ideas from their corner of the universe. Sign up for Lost in Space-Time here.
Clocks regulate our lives, dictating when we sleep and wake, whether we catch our flights home and who wins a fortune on Wall Street. And just as clocks govern us, they govern quantum devices.
Take quantum computers. A basic part of performing any computation is executing certain tasks at certain times. External classical control systems keep time for today’s quantum computers, but a control system that could operate entirely within the quantum realm would open up new possibilities. Giving our imaginations free rein, we might envision tiny quantum drones that can tinker with or deliver molecules. Such autonomous machines would have to carry their own clocks and those clocks would have to be quantum too to prevent the machines from losing their quantum character. For instance, quantum technologies benefit from entanglement, strong correlations that sync quantum particles. The more a quantum drone interacted with ordinary devices, the more its entanglement could dissipate.
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The question is, can we build such a quantum clock that would do the job?
Before we dive in, I should clarify that an autonomous quantum clock is not the same as the so-called atomic clocks that you can buy in stores. My grandparents bought such an “atomic clock” and hung it in their kitchen, but theirs would have been more accurately called a “radio-controlled clock”. Every day, the clock received radio signals from a Colorado outpost of the National Institute of Standards and Technology (NIST), synchronising it with a highly accurate clock operated by NIST.
NIST’s clock was an actual atomic clock – a quantum clock, but one whose controller didn’t exist entirely within the quantum realm. An atomic clock contains atoms that can absorb only certain amounts of energy in discrete packets – like someone who can eat one packet of crisps but not half a packet. A laser shines on the atoms, and an external controller measures how many atoms have, so to speak, eaten crisp packets from the laser. If many atoms have, then the laser’s light consists of particles with just the right amount of energy – an amount calculable with quantum theory. In addition to consisting of particles, the light has wave-like properties and so, in a sense, oscillates up and down. The time between oscillations is a calculable fraction of a second, which is defined in terms of the energy that the atoms can absorb. So we measure a second by waiting for the laser light to oscillate a certain number of times. The controller that measures the atoms’ energy isn’t quantum, so an atomic clock is not the only clock we’ll need for the quantum steampunk age.
Quantum physics pioneer Wolfgang Pauli spent time in the 1920s thinking about quantum clocks, among many other things. Pauli’s interests extended from quantum physics to psychology and philosophy, and his name is now tied to the Pauli exclusion principle that governs how electrons organise in atoms. He homed in on simple, yet fundamental concepts – and what is time, if not fundamental?
Pauli pointed out that an ideal quantum clock has a time “observable”. Observable is the physics name for a measurable property of a quantum system. Example observables include energy, position and momentum. An ideal quantum clock’s time observable has a well-defined value. How could an observable not have a well-defined value? After all, you have a well-defined energy, position, and momentum. But quantum position and momentum participate in an uncertainty relation. If a quantum particle has a well-defined position, the particle doesn’t have a well-defined momentum; in quantum lingo, the particle is in a superposition of all possible momenta. If you measure the momentum, your detector can read any positive number, any negative number or zero. Analogous to the particle’s well-defined position is an ideal quantum clock’s well-defined time; the clock would not be in a superposition of many times.
But time and energy participate in an uncertainty relation similarly to position and momentum. So a quantum system with a well-defined time would be in a superposition of all possible energies. Moreover, the superposition would be spread evenly across all possible energies: if you measured the clock’s energy, your probability of obtaining one possible outcome would equal your probability of obtaining any other possible outcome.
Infinitely negative energy
Pauli proved mathematically that no quantum system can have a time observable. If a system did, it could have an infinitely negative amount of energy. Having an infinitely negative amount of energy is impossible in our world. So, according to quantum mechanics, our world doesn’t accommodate time observables – or ideal quantum clocks.
Luckily, we don’t need an ideal quantum clock – a good-enough quantum clock could be, well, good enough. Just how drawing a round shape on a piece of paper can approximate a circle, so too can a quantum clock approximate an ideal one. And three colleagues of mine – Jonathan Oppenheim, Mischa Woods and Ralph Silva – have managed to design such a quantum clock.
As Jonathan and Mischa explained to me when I visited them in London one spring, their theoretical clock is in an approximation to the ideal time state, the superposition spread evenly across all energies. Their superposition is spread unevenly in a particular pattern: if you measure the clock’s energy, you’re more likely to obtain some outcomes than others. So the clock’s energy is still uncertain, just not maximally uncertain. The clock therefore doesn’t break the laws of physics à la Pauli.
Moreover, the clock is fairly stable. Reading a quantum clock is not like reading a classical one. The act of using it to determine the time would trigger a counterintuitive quantum phenomenon: measurement disturbance. You can observe an everyday clock without affecting which time it reports, just as a police officer can register your car’s speed without your noticing (hence the existence of speeding tickets). But quantum systems are more delicate than everyday systems. If you measure a quantum system – or interact with it any other way – you disturb it, changing its state. If you measure the system’s energy, you’ll likely change its energy.
Reading the time off a quantum clock wouldn’t interfere with timekeeping if the clock were ideal. But an imperfect clock would degrade with use, reducing our ability to distinguish instants. You might as well gaze at a grandfather clock through increasingly blurry glasses: 6 o’clock will blend into 5.59 and 6.01, then into 5.58 and 6.02. Disturbances also hinder the clock’s ability to initiate processes, such as logic gates in a computation, at desired times.
How well could Mischa, Ralph, and Jonathan’s clock withstand such disturbances? Not too poorly, you could say, if channelling my Britain-based colleagues. Imagine growing the clock – adding particles to it, although not so many particles that the clock loses its quantum nature. The bigger the clock, the greater its resilience. And giving a little gets you a lot: as the clock grows, its resilience grows exponentially.
So far, such properties remain theoretical, and scientists are hard-pressed to build even externally controlled quantum computers, let alone autonomous ones. But experiments’ control over quantum systems has advanced rapidly over the past three decades and shows no signs of slowing down. Will autonomous clocks enable quantum computers and other machines to operate independently? Whether measured on a quantum clock or an everyday one, time will tell.
Nicole Yunger Halpern, runs arguably the best-named research group in the universe: The Quantum-Steampunk Laboratory. Her work involves re-envisioning thermodynamics for the quantum age. The physics of steam engines and industrial machinery was worked out about a century before quantum theory was crystallised in the 1920s – and nearly two centuries before tech start-ups began using quantum physics to build computers and sensors – so she and her team believe thermodynamics is now due an update.
