China on Monday released the first Mars global images obtained from its first Mars exploration mission, providing an improved quality base map for scientific and exploration tasks on the Red Planet, the Global Times learned from the China National Space Administration (CNSA) at the opening ceremony of this year's Space Day of China.
The color images, jointly issued by the CNSA and the Chinese Academy of Sciences (CAS), included orthographic, Robinson, Mercator and azimuthal projections of the eastern and western hemispheres of Mars with a spatial resolution of 76 meters.
The image maps will provide an improved quality base map for Mars exploration projects and scientific research, the CNSA said, and data obtained by the Tianwen mission will make key contributions to humanity's in-depth knowledge of the planet.
The medium-resolution camera onboard Tianwen-1 took 284 orbital remote sensing images from November 2021 to July 2022, so as to achieve global coverage of the Martian surface. Some 14,757 images were acquired by the ground-based application system, which were then processed to obtain the global color image map of Mars.
China's panoramic map of Mars is one of the most advanced in the field that is open to the public, experts noted, and it means that China is willing to share cutting-edge technology and information with its peers.
"This year's China Space Day underscores our willingness to share information with the world, showing that China's space achievements are entirely for the development of human scientific and technological progress. It also suggests our growing confidence in this field," Song Zhongping, a space analyst and TV commentator, told the Global Times on Monday.
"Technology has no borders, but the US has been constantly putting up shields and fences to block others from its technology, as well as engaging in technological monopolies, information hegemony and a Cold War in space," he said.
At the opening ceremony on Monday, the CNSA also disclosed that 22 sites on Mars have been given Chinese names.
China's research teams have identified a large number of geographical entities near the landing site of Tianwen through high-resolution images, and the International Astronomical Union has named 22 of them after villages in China with historical and cultural significance and a population of less than 100,000.
In this way, China's presence is permanently engraved on Mars' surface.
Tianwen-1, China's first Mars mission probe, embarked on its journey on July 23, 2020, and after 202 days of travel, it began to orbit Mars. On May 15, 2021, the land rover Zhurong landed in a designated spot on the Martian surface and started its trek. It completed its 90-Martian-day scientific exploration task and kept working for another 268 Martian days, and has remained in hibernation mode since.
As of June 29, 2022, the Mars orbiter had carried out global remote sensing for more than 1,000 days, and it is still carrying on its mission in fine condition.
China's first Mars mission, which orbits Mars, land and rove in one go, was completed successfully.
The 13 payloads carried by the mission have accumulated 1,800 gigabytes of scientific data and formed standard data products.
Over the past two years, Tianwen-1 has obtained first-hand detection data and achieved notable scientific research results, which analysts said would be continued with further multi-dimensional exploration missions being carried out.
In May 2022, a research team from the CAS detected water-bearing minerals on Mars by analyzing data collected by the Zhurong rover, marking a world first that water-bearing minerals on the planet were detected by a short-wave infrared spectrometer on a Mars rover. The findings have been published in detail in the journal Science.
Another major discovery by the Chinese Mars rover came when scientists used a ground-penetrating radar on Zhurong to find possible evidence of floods on the Red Planet billions of years ago. Though no direct evidence for liquid water was found in the shallow subsurface, the study lends weight to the theory that the rover's landing area - the Utopia Planitia - once hosted an ancient ocean, researchers from the CAS and Peking University said in a Nature paper published in September 2022.
China launched its largest solid propellant rocket Lijian-1 on Wednesday, successfully sending 26 satellites into preset orbit and setting the country's new record for launching multiple satellites in one go. The satellites will mainly provide commercial remote sensing information services.
The Wednesday launch marks the second flight of Lijian-1, indicating the maturity of the solid propellant rocket's technology and the continuous improvement of its reliability, which can further boost the commercialization of China's launch vehicles.
In an exclusive interview with the Global Times, chief engineer assistant on Lijian-1 Shi Xiaoning said he was quite confident about the rocket as its reliability has been verified. But he was still concerned about the separation of satellites from the rocket.
"This time, there were more satellites to send and we not only needed to ensure that each of them could be successfully separated, but also ensure the accuracy of the satellite's orbit insertion, which was quite challenging," Shi said. "Therefore, we closely monitored data for each satellite separation, but in the end we accurately delivered each satellite to the designated orbit."
Lijian-1 made its maiden flight on July 27, 2022, successfully sending six satellites into their preset orbits. According to its developer, the Chinese Academy of Sciences (CAS), the 2.65-meter-diameter and 30-meter-long new rocket is the largest of its kind in China.
It has achieved breakthroughs in six key technologies and utilized 13 domestic technologies for the first time, enriching China's spectrum of solid carrier rocket launch capabilities and making significant contributions to the technological transformation of China's carrier rocket industry.
Lijian-1 is a four-stage launch vehicle weighing 135 tons at launch with a thrust of 200 tons. It is capable of sending payloads of 1,500 kilograms into 500-kilometer Sun-synchronous orbits (SSO). Prior to that, the capacity of Chinese commercial space rockets in SSO was below 1,000 kilograms.
For the next step, the rocket developer Guangzhou Zhongke Aerospace Exploration Technology Co (CAS Space) will continue to enrich the spectrum of China's solid propellant launch vehicles. In addition to building a sea launch platform for Lijian-1, a new solid rocket with a diameter of 3.5 meters is also under development, the Global Times has learned.
The future of disease tracking is going down the drain — literally. Flushed with success over detecting coronavirus in wastewater, and even specific variants of SARS-CoV-2, the virus that causes COVID-19, researchers are now eyeing our collective poop to monitor a wide variety of health threats.
Before the pandemic, wastewater surveillance was a smaller field, primarily focused on testing for drugs or mapping microbial ecosystems. But these researchers were tracking specific health threats in specific places — opioids in parts of Arizona, polio in Israel — and hadn’t quite realized the potential for national or global public health. Then COVID-19 hit.
The pandemic triggered an “incredible acceleration” of wastewater science, says Adam Gushgari, an environmental engineer who before 2020 worked on testing wastewater for opioids. He now develops a range of wastewater surveillance projects for Eurofins Scientific, a global laboratory testing and research company headquartered in Luxembourg.
A subfield that was once a few handfuls of specialists has grown into more than enough scientists to pack a stadium, he says. And they come from a wide variety of fields — environmental science, analytical chemistry, microbiology, epidemiology and more — all collaborating to track the coronavirus, interpret the data and communicate results to the public. With other methods of monitoring COVID-19 on the decline, wastewater surveillance has become one of health experts’ primary sources for spotting new surges.
Hundreds of wastewater treatment plants across the United States are now part of COVID-19 testing programs, sending their data to the National Wastewater Surveillance System, or NWSS, a monitoring program launched in fall 2020 by the U.S. Centers for Disease Control and Prevention. Hundreds more such testing programs have launched globally, as tracked by the COVIDPoops19 dashboard run by researchers at the University of California, Merced.
In the last year, wastewater scientists have started to consider what else could be tracked through this new infrastructure. They’re looking at seasonal diseases like the flu, recently emerging diseases like bird flu and mpox, formerly called monkeypox, as well as drug-resistant pathogens like the fungus Candida auris. The scientists are even considering how to identify entirely new threats.
Wastewater surveillance will have health impacts “far broader than COVID,” predicts Amy Kirby, a health scientist at the CDC who leads NWSS.
But there are challenges getting from promise to possible. So far, such sewage surveillance has been mostly a proof of concept, confirming data from other tracking systems. Experts are still determining how data from our poop can actually inform policy; that’s true even for COVID-19, now the poster child for this monitoring. And they face public officials wary of its value and questions over whether, now that COVID-19 health emergencies have ended, the pipeline of funding will be cut off.
This monitoring will hopefully become “one of the technologies that really evolves post-pandemic to be here to stay,” says Mariana Matus, cofounder of Biobot Analytics, a company based in Cambridge, Mass., that has tested sewage for the CDC and many other health agencies. But for that to happen, the technology needs continued buy-in from governments, research institutions and the public, Matus and other scientists say.
How wastewater testing works Wastewater-based epidemiology has a long history, tracing back at least to physician John Snow’s 1850s observations that cholera outbreaks in London were connected to contaminated water. In the 1920s and ’30s, scientists began to take samples from sewage and study them in the lab, learning to isolate specific pathogens that cause disease. These early researchers focused on diseases that spread through contaminated water, such as polio and typhoid.
Today, automated machines typically retrieve sewage samples. The machines used to collect waste beneath maintenance hole covers are “like R2-D2 in terms of size” or smaller, says Erin Driver, an environmental engineer at Arizona State University in Tempe who works on collection methods.
Driver can plug this machine, or a larger version used for sampling at wastewater treatment plants, into a water pipe and program it to pull a small amount of sewage into an empty bottle at regular intervals, say, once an hour for 24 hours. She and colleagues are developing smaller versions of the automated sampler that could be better suited for more targeted sampling.
What happens in the lab to that bottle of waste depends on what scientists are testing for. To test for opioids and other chemicals, scientists might filter large particles out of the sample with a vacuum system, extract the specific chemicals that they want to test, then run the results through a spectrometer, an instrument that measures chemical concentrations by analyzing the light the chemicals give off.
To determine levels of SARS-CoV-2 or another virus, a scientist might separate liquid waste from solid waste with a centrifuge, isolate viral genetic material, and then test the results with a PCR machine, similar to testing someone’s nose swab. Or, if scientists want to know which SARS-CoV-2 variants are present, they can put the material through a machine that identifies a variety of genetic sequences.
Would the coronavirus even show up in waste? In the panicked early days of the pandemic, an urgent basic question loomed. “Will this even work?” remembers Marlene Wolfe, an environmental microbiologist at Emory University in Atlanta. While polio is spread through fecal matter, there were early hints that the coronavirus mostly spreads through the air; scientists initially weren’t even sure that it would show up in sewage.
On the same day in 2020 that the San Francisco Bay Area went on lockdown, Wolfe and colleagues at Stanford University, where she was based at the time, got a grant to find out. The team was soon spending hours driving around the Bay Area to collect sewage samples, “navigating lockdown rules” and negotiating special permissions to use lab space, she says.
“We were anxiously waiting to see if our first samples would show a positive result for SARS-CoV-2,” Wolfe says.
Not only did the sewage samples test positive, Wolfe and her colleagues found that coronavirus levels in the Bay Area’s wastewater followed the same trends as reported cases, the team reported in December 2020 in Environmental Science & Technology. When case counts went up, more virus appeared in the sewage, and vice versa. Early projects in other parts of the country showed similar results. More than three years later, data on reported cases have become much less reliable. Fewer people are seeking out lab-based PCR tests in favor of easier-to-access at-home tests — with results often not reported. Wastewater trends have become the best proxy to provide early warnings of potential new COVID-19 surges, such as the increased spread this summer, to health officials and the public alike.
Opening the tracking floodgates In summer 2022, wastewater tracking got a new chance to prove itself. Mpox was rapidly spreading globally, including in the United States. But tests were limited, and the disease, which was spreading primarily through intimate contact between men, quickly drew social stigma, leading some people to hesitate in seeking medical care.
Within a few weeks of the start of the U.S. outbreak, Wolfe and her colleagues, as well as research teams at Biobot and other companies, had developed tests to identify mpox in sewage.
Just as scientists had seen with COVID-19, mpox trends in wastewater matched trends in official case numbers. In California, wastewater results even suggested that the disease may have spread farther than data from doctors’ offices suggested, Wolfe and collaborators reported in February in the New England Journal of Medicine.
Like COVID-19, mpox doesn’t transmit through the water, but sewage testing still picked up the virus. The early results from that summer outbreak convinced some health officials that wastewater technology could be used for many diseases, no matter how they spread, Matus says. Scientists are starting to find more and more infectious diseases that can be tracked in sewage. “Honestly, everything that we’ve tried so far has worked,” says Wolfe, who is now a principal investigator of WastewaterSCAN, a national sewage testing project led by researchers at Stanford and Emory. The project team currently tests samples for six different viruses and is working on other tests that it can send out to the more than 150 sites in its monitoring network.
Through an informal literature review of pathogens important for public health, scientists at Biobot found that previous research had identified 76 out of 80 of them in wastewater, stool or urine, suggesting that those pathogens could be monitored through sewage. The list ranges from the chicken pox virus to the microbes that cause sexually transmitted diseases like chlamydia to the tickborne bacteria that cause Lyme disease.
Finding focus With this much opportunity, the question on many researchers’ minds is not, “What can we test for?” but “What should we test for?”
In January, a report put out by the National Academies of Sciences, Engineering and Medicine came up with three criteria. The pathogen should threaten public health. It should be detectable in wastewater. And it should generate data that public health agencies can use to protect their communities.
Given all the threats and hints of what can be found in wastewater, the first two criteria don’t narrow the field too much. So for now, researchers are taking cues from state and local public health officials on which pathogens to prioritize.
Biobot is working on tests for common diseases like the flu, RSV, hepatitis C and gonorrhea. And the CDC has its eye on some of the same common pathogens, as well as strategies for tracking antimicrobial resistance, a threat that has increased during the pandemic as health systems have been under strain.
Even if they choose the perfect targets, though, researchers also have to figure out how to generate useful data. For now, that’s a sticking point.
How to use the data Tracking pathogens is one thing. But determining how the results correspond to actual numbers of sick people is another, even in the case of COVID-19, where researchers now have years of detailed data. As a result, many public health officials aren’t yet ready to make policy decisions based on poop data.
In New York City over the last three years, for example, the local government has poured more than $1 million into testing for COVID-19, mpox and polio in sewage from the city’s water treatment plants. But the city’s health department hasn’t been using the resulting data to inform local COVID-19 safety measures, so it’s unclear what’s being done with the data. Health officials are used to one swab per person, says Rachel Poretsky, a microbiologist at the University of Illinois Chicago. She also heads wastewater monitoring for the city of Chicago and the state of Illinois.
Public health training relies on identifying individual sick people and tracing how they became ill. But in wastewater surveillance, one data point could represent thousands of sick people — and the data come from the environment, rather than from hospitals and health clinics. What to do next when positive results turn up isn’t as obvious.
Numbers collected from the health care system always represent patients, so a spike indicates a surge in cases. In the case of sewage data, however, environmental factors like weather, local industries and the coming and going of tourists also can create “weird outliers” that resist easy interpretation, Poretsky says. For instance, a massive rainstorm might dilute samples, or chemical runoff from a factory might interfere with a research team’s analytical methods.
Data interpretation only gets more complicated when scientists begin testing wastewater for an increasing number of health threats. Every pathogen’s data need to be interpreted differently.
With coronavirus data, for example, wastewater tests consistently come back positive, so interpreting the data is all about looking for trends: Are viral concentrations going up or down? How does the amount of virus present compare with the past? A spike in a particular location might signal a surge in the community that hasn’t yet been picked up by the health care system. The community might respond by boosting health resources, such as opening vaccine clinics, handing out free masks and at-home tests, or adding staff to local hospital emergency departments.
Mpox, on the other hand, has infected far fewer people, and positive tests have been rare after last summer’s outbreaks ended. Now, researchers are simply watching to see whether the virus is present or absent in a given sewershed.
“It’s more about having an early warning,” Matus says. If a sewershed suddenly tests positive for mpox after negative results for the last few months, health officials might alert local doctors and community organizations to look out for anyone with symptoms, aiming to identify any cases and prevent a potential outbreak.
Another complicated pathogen is C. auris, a fungus that has developed resistance to common drugs. It can spread rapidly in health care settings — and be detected in sewage. Researchers from Utah and Nevada reported in February in Emerging Infectious Diseases that it was possible to track C. auris in the sewage from areas experiencing outbreaks.
If hospitals or health officials could identify the presence of this fungus early, that information could guide public health actions to curb outbreaks, says Alessandro Rossi, a microbiologist at the Utah Public Health Laboratory in Salt Lake City. But interpreting the warnings isn’t as clear-cut for C. auris as for viruses.
The fungus can grow in sewage after it leaves health care facilities, Rossi says. The pathogen has “the potential to replicate, form biofilms and colonize a sewershed.” In other words, C. auris can create its own data interference, potentially making wastewater results seem worse than they really are. Moving wastewater into the future Most current testing programs are reactive. By looking at health threats one at a time using specific PCR tests, the programs mostly confirm that pathogens we already are worrying about are getting people sick.
But some scientists, like Wim Meijer, envision a future in which wastewater monitoring wades into the unknown and alerts us to unusual disease outbreaks. The microbiologist, of the University College Dublin, heads Ireland’s wastewater surveillance program. Ideally, in this ahead-of-the-curve future, after detecting something alarming in sewage, his team could closely collaborate with health officials to study the pathogen and, if necessary, start combating the threat.
One idea for turning the tech proactive is to prepare for new health threats that we can see coming. For example, Meijer and his colleagues are interested in screening Ireland’s sewage for the H5N1 bird flu, but they are not yet doing this testing.
Another approach takes advantage of genetic testing technology to look at everything in our waste. Kartik Chandran, an environmental engineer at Columbia University who has mapped sewers’ microbial ecosystems with this technique, describes it as “trying to shine the light more broadly” rather than looking where the light is already shining brightest.
Such an approach might identify new pathogens before sick people start going to the doctor’s office, potentially leading to an earlier public health response. But with health officials still unsure of how best to use wastewater data, much more basic research is needed first. “People think wastewater surveillance is the answer to everything, and clearly that’s not true,” says Kirby, of the CDC, reflecting concerns from the state and local officials that she collaborates with at NWSS. Before diving ahead into proactive surveillance, Kirby and her colleagues are working to set up basic wastewater standards and protocols for health agencies. Priorities include evaluating how sewage trends correlate to cases for different pathogens and developing standards for how to use the data.
The wastewater surveillance field also needs to keep growing if the goal is to monitor and contribute to global health, with more sites contributing data and more scientists to analyze it. All of this work requires sustained funding.
The CDC’s program so far has been funded by COVID-era legislation and will run out of money in 2025. While wastewater surveillance is more cost-effective than other types of testing, it still requires a lot of resources. Washington’s state health department, for example, paid Biobot more than $500,000 for a one-year sewage testing contract, while the CDC has paid the company more than $23 million since 2020 for its work with NWSS.
For the last few years, wastewater surveillance has been a giant, messy group project. Scientists have collaborated across fields and locations, across private and public institutions, through Zoom calls and through poop samples shipped on ice. They’ve shown that waste might hold the key to a new way of tracking our collective health.
A lot of unanswered questions remain, and it could be some time before your local sewer can tell you exactly what disease risks you might be facing. But COVID-19 pushed thousands of experts to look into their toilets and start asking those questions. “Now, everyone’s a believer,” says Driver, of ASU. “Everyone’s doing the work.”
Tianjin Customs recently seized 92 globes that mistakenly labeled China's Taiwan region alongside the name of countries, violating the one-China principle, according to China's General Administration of Customs (GAC) on Thursday.
The globes were discovered by on-site customs officers at North China's Tianjin's Xingang Customs, during the inspection of a declared imported shipment of globes in the import freight channel, according to the GAC.
The globes have been seized according to law and will be further processed.
The GAC said that maps are the main representation of the national territory. A correct national map is a symbol of national sovereignty and territorial integrity.
All printed matter and publications that do not comply with China's regulations on the content representation of open map are strictly prohibited from printing or importing/exporting, according to the GAC.
Additionally, relevant map or map product production and import-export enterprises should strictly comply with laws and regulations and carry out map business activities in accordance with the law.
China's Ministry of Natural Resources (MNR) issued the open map content representation specification in February, requiring open maps or the content representation of map graphics products, should comply with the specification. Detailed requirements have been specified to regulate the depiction of maps concerning China's Taiwan region, the South China Sea, and the Diaoyu Islands, among other areas.
Chinese President Xi Jinping on Saturday urged firmly grasping the strategic positioning of Xinjiang in the overall national situation and better building a beautiful Xinjiang in the process of pursuing Chinese modernization.
Xi, also general secretary of the Communist Party of China (CPC) Central Committee and chairman of the Central Military Commission, made the remarks when he was briefed in Urumqi about the work of the Party committee and government of northwest China's Xinjiang Uygur Autonomous Region, as well as the Xinjiang Production and Construction Corps.
He demanded thorough, meticulous, concrete and sustained efforts to develop a beautiful Xinjiang that is united, harmonious, prosperous, and culturally advanced, with healthy ecosystems and people living and working in contentment, in the process of pursuing Chinese modernization.
Xi was in Xinjiang after returning to China from the 15th BRICS Summit and a state visit to South Africa.
Recognizing Xinjiang's achievements in various aspects, Xi said the work related to Xinjiang is of special importance in the work of the Party and the country, and concerns the overall task of building China into a strong modern socialist country in all respects and promoting the rejuvenation of the Chinese nation.
Efforts should be made not only to address prominent problems currently constraining Xinjiang's development and stability, but also to make long-term arrangements to promote fundamental, basic and long-term work for enduring prosperity and stability in the region, he said.
Maintaining social stability is a top priority, Xi said, urging efforts to coordinate the work of maintaining stability and advancing development, the two aspects that are mutually promoted. He also called for efforts to enhance the rule of law to build a solid legal foundation for enduring stability.
The mechanism for forestalling and defusing major risks and potential dangers should be improved, Xi said, adding that the fight against terrorism and separatism should be integrated with law-based and constant work of maintaining stability.
Forging a strong sense of community for the Chinese nation is a focus of the CPC's work on ethnic affairs in the new era and all work in areas with large ethnic minority populations, Xi said.
He said the education on standard spoken and written Chinese must be resolutely carried out to enhance people's consciousness and capability to use it.
He also stressed the importance of strengthening the protection and use of cultural relics and heritage to help officials and the public develop an accurate understanding of state, ethnicity, history, and religions.
Xi called for enhanced education on modern civilization and science among the youth and teenagers and encourage them to get involved in modern life. He emphasized advancing people-centered new urbanization and promoting exchanges and interactions among all ethnic groups.
Xi said Xinjiang should take the initiative in grasping fresh opportunities arising from the nation's drive to create a new development pattern, advance high-quality development and push for Chinese modernization.
Xinjiang should advance innovation in science and technology, foster and develop industries with unique advantages, and actively develop emerging industries. Efforts should be made to accelerate the construction of a modern industrial system that reflects Xinjiang's characteristics and strengths, and help Xinjiang advance on the track of high-quality development, he said.
To achieve social stability and high-quality development in Xinjiang, the most arduous task is in rural areas, Xi said, emphasizing the work to consolidate and build on the achievements of poverty alleviation and promote rural revitalization.
He called for more industrial cooperation and personnel exchange between Xinjiang and the rest of the country, and encouraged people from Xinjiang to work outside the region and people in other parts of the country to start business and live in Xinjiang.
With unique geographical advantages, Xinjiang should accelerate the construction to make itself the gateway of China's westward opening up, Xi said.
Xi asked Party members and officials to stay engaged with the people and their communities. He said Party organizations at the primary level must be strengthened to learn about the people's concerns and timely respond to their difficulties and problems.
He stressed the need to better tell Xinjiang stories in the new era through multiple channels to show an open and confident Xinjiang, while refuting fake and baleful statements targeting Xinjiang.
Xinjiang will open more widely for tourism and encourage domestic and overseas tourists to travel in the region, he said.
Xi stressed upholding the Party's overall leadership and strengthening the Party building in Xinjiang. He underscored the importance of resolutely upholding the Party Central Committee's authority and its centralized, unified leadership.
Cai Qi, a member of the Standing Committee of the Political Bureau of the CPC Central Committee and a member of the Secretariat of the CPC Central Committee, attended the briefing.
Japanese great tits (Parus minor) communicate using at least 10 different notes on their own and in combination. Researchers played different calls for Japanese great tits in a forest in Nagano, Japan, to see how the birds responded — an indication of what the call might mean. The birds responded differently to individual notes than they did when played the same note in combination with other notes. And, when researchers reversed the note order, the birds didn’t respond the same way. By itself, a note means one thing to great tits, but in combination, it means something different, the team argues March 8 in Nature Communications. Similarly, among humans, the order of words in a sentence, its compositional syntax, matters.
Some primates combine calls to convey different messages, but individual notes don’t carry unique meaning in these species. Great tits are the first nonhuman species shown to use compositional syntax, the researchers write. In this recording, researchers played three types of calls for Japanese great tits: First, a call with three notes — A, B, and C — which signals danger; second, a one-note call (D), which attracts mates; and finally, a combination call, ABC-D, which causes the birds to scan the skies for predators and fly to the source of the sound. Researchers played an ABC-D call for great tits, and then reversed an ABC-D call. Birds responded differently in each case.
In a pair of twin sisters, a rare disease had damaged the brain’s structures believed necessary to feel fear. But an injection of a drug could nevertheless make them anxious.
The results of that experiment, described in the March 23 Journal of Neuroscience, add to evidence that the amygdalae, small, almond-shaped brain structures tucked deep in the brain, aren’t the only bits of the brain that make a person feel afraid. “Overall, this suggests multiple different routes in the brain to a common endpoint of the experience of fear,” says cognitive neuroscientist Stephan Hamann of Emory University in Atlanta. The twins, called B.G. and A.M., have Urbach-Wiethe disease, a genetic disorder that destroyed most of their amygdalae in late childhood. Despite this, the twins showed fear after inhaling air laden with extra carbon dioxide (an experience that can create the sensation of suffocating), an earlier study showed (SN: 3/23/13, p. 12). Because carbon dioxide affects a wide swath of the body and brain, scientists turned to a more specific cause of fear that stems from inside the body: a drug called isoproterenol, which can set the heart racing and make breathing hard. Sensing these bodily changes provoked by the drug can cause anxiety.
“If you know what adrenaline feels like, you know what isoproterenol feels like,” says study coauthor Sahib Khalsa, a psychiatrist and neuroscientist at the Laureate Institute for Brain Research in Tulsa, Okla.
After injections of isoproterenol, both twins felt shaky and anxious. B.G. experienced a full-blown panic attack, a result of the drug that afflicts about a quarter of people who receive it, says Khalsa. In a second experiment, researchers tested the women’s ability to judge their bodies’ responses to the drug. While receiving escalating doses, the women rated the intensity of their heartbeats and breathing. A.M., the woman who didn’t have a panic attack, was less accurate at sensing the drug’s effects on her body than both her sister and healthy people, researchers found.
It’s not clear why the twins responded differently, Khalsa says. Further experiments using brain scans may help pinpoint neural differences that could be behind the different reactions.
The results suggest that the amygdala isn’t the only part of the brain involved in fear and anxiety, but there’s more work to do before scientists understand how the brain creates these emotions, Khalsa says. “It’s definitely a complicated question and a debate that’s unresolved,” he says.
Despite massive public health campaigns, the rise in worldwide obesity rates continues to hurtle along like a freight train on greased tracks.
In 2014, more than 640 million men and women were obese (measured as a body mass index of 30 or higher). That’s up from 105 million in 1975, researchers estimate in the April 2 Lancet. The researchers analyzed four decades of height and weight data for more than 19 million adults, and then calculated global rates based on population data. On average, people worldwide are gaining about 1.5 kilograms per decade — roughly the weight of a half-gallon of ice cream. But the road isn’t entirely rocky. During the same time period, average life expectancy also jumped: from less than 59 years to more than 71 years, George Davey Smith points out in a comment accompanying the new study. Smith, an epidemiologist at the University of Bristol in England, boils the data down to a single, seemingly paradoxical sentence: “The world is at once fatter and healthier.”
Bees may need their own supplemental protein shakes as increasing carbon dioxide in the atmosphere saps the nutritional quality of pollen.
Pollen collected from plants gives bees their only natural source of protein (nectar is a sugar-shot for energy). Yet protein content in pollen of a widespread goldenrod species (Solidago canadensis) dwindled by a third, from about 18 percent to 12 percent, over 172 years, according to analysis of recently collected flowers and of preserved specimens at the Smithsonian Institution’s National Museum of Natural History. During those same years, CO2 concentrations in the atmosphere increased from about 280 parts per million to 398 ppm, researchers report April 12 in Proceedings of the Royal Society B. The same themes also showed up in two years of growing the goldenrod at CO2 concentrations up to 500 ppm. More CO2 meant less concentrated protein in pollen, say Lewis Ziska of the U.S. Department of Agriculture’s Bee Research Laboratory in Beltsville, Md., and his colleagues.
“It’s like you’re eating a starchier diet — what would that do to us?” says study coauthor Joan Edwards of Williams College in Williamstown, Mass. “Bees aren’t so different.”
Bees, wild or domesticated, need adequate protein to feed their larvae, maintain their immune systems and for many more functions, says bee biologist Cédric Alaux of the French agricultural research agency INRA in Avignon. Canada goldenrod is an example of a species known to offer pollen that can be stored to tide honeybees over the winter. The one-third decrease in protein concentration reported in the new study is big enough to shorten bee life spans, he says.
Lower quality in bee food sources could be contributing to global bee declines observed in recent years and the uncertain state of pollination for crops, Edwards says. “The health of the bee population is not just for the flowers and the bees and biodiversity, but also for human health and well-being.”
For beings that are supposedly alien to human culture, extraterrestrials are pretty darn common. You can find them in all sorts of cultural contexts, from comic books, sci-fi novels and conspiracy theories to Hollywood films and old television reruns. There’s Superman and Doctor Who, E.T. and Mindy’s friend Mork, Mr. Spock, Alf, Kang and Kodos and My Favorite Martian. Of course, there’s just one hitch: They’re all fictional. So far, real aliens from other worlds have refused to show their faces on the real-world Earth — or even telephone, text or tweet. As the Italian physicist Enrico Fermi so quotably inquired during a discussion about aliens more than six decades ago, “Where is everybody?” Scientific inquiry into the existence of extraterrestrial intelligence still often begins by pondering Fermi’s paradox: The universe is vast and old, so advanced civilizations should have matured enough by now to send emissaries to Earth. Yet none have. Fermi suspected that it wasn’t feasible or that aliens didn’t think visiting Earth was worth the trouble. Others concluded that they simply don’t exist. Recent investigations indicate that harsh environments may snuff out nascent life long before it evolves the intelligence necessary for sending messages or traveling through space. In any event, Fermi’s question did not launch humankind’s concern with visitors from other planets. Imagining other worlds, and the possibility of intelligent life-forms inhabiting them, did not originate with modern science or in speculative fiction. In the ancient world, philosophers argued about the possibility of multiple universes; in the Middle Ages the question of the “plurality of worlds” and possible inhabitants occupied the deepest of thinkers, spawning intricate and controversial philosophical, theological and astronomical debate. Far from being a merely modern preoccupation, life beyond Earth has long been a burning issue animating the human race’s desire to understand itself, and its place in the cosmos.
Other worlds, illogical From ancient times Earth’s place was widely regarded to be the center of everything. As articulated by the Greek philosopher Aristotle, the Earth was the innermost sphere in a universe, or world, surrounded by various other spheres containing the moon, sun, planets and stars. Those heavenly spheres, crystalline and transparent, rotated about the Earthly core comprising four elements: fire, air, water and earth. Those elements layered themselves on the basis of their essence, or “nature” — earth’s natural place was at the middle of the cosmos, which was why solid matter fell to the ground, seeking the inaccessible center far below.
On the basis of this principle, Aristotle deduced the impossibility of other worlds. If some other world existed, its matter (its “earth”) would seek both the center of its world and of our world as well. Such opposite imperatives posed a logical contradiction (which Aristotle, having more or less invented logic, regarded as a directly personal insult). He also applied further reasoning to point out that there is no space (no void) outside the known world for any other world to occupy. So, Aristotle concluded, two worlds cannot both exist.
Some Greeks (notably those advocating the existence of atoms) believed otherwise. But Aristotle’s view prevailed. By the 13th century, once Aristotle’s writings had been rediscovered in medieval Europe, most scholars defended his position. But then religion leveled the philosophical playing field. Fans of other worlds got a chance to make their case.
In 1277, the bishop of Paris, Étienne Tempier, banned scholars from teaching 219 principles, manny associated with Aristotle’s philosophy. Among the prohibited teachings on the list was item 34: that God could not create as many worlds as he wanted to. Since the penalty for violating this decree was excommunication, Parisian scholars suddenly discovered rationales allowing multiple worlds, empowering God to defy Aristotle’s logic. And since Paris was the intellectual capital of the European world, scholars elsewhere followed the Parisian lead. While several philosophers asserted that God could make many worlds, most intimated that he probably wouldn’t have bothered. Hardly anyone addressed the likelihood of alien life, although both Jean Buridan in Paris and William of Ockham in Oxford did consider the possibility. “God could produce an infinite [number of] individuals of the same kind as those that now exist,” wrote Ockham, “but He is not limited to producing them in this world.” Populated worlds showed up more prominently in writings by the renegade thinkers Nicholas of Cusa (1401–1464) and Giordano Bruno (1548–1600). They argued not only for the existence of other worlds, but also for worlds inhabited by beings just like, or maybe better than, Earth’s humans.
“In every region inhabitants of diverse nobility of nature proceed from God,” wrote Nicholas, who argued that space had no center, and therefore the Earth could not be central or privileged with respect to life. Bruno, an Italian friar, asserted that God’s perfection demanded an infinity of worlds, and beings. “Infinite perfection is far better presented in innumerable individuals than in those which are numbered and finite,” Bruno averred.
Burned at the stake for heretical beliefs (though not, as often stated, for his belief in other worlds), Bruno did not live to see the triumph of Copernicanism during the 17th century. Copernicus had placed the sun at the hub of a planetary system, making the Earth just one planet of several. So the existence of “other worlds” eventually became no longer speculation, but astronomical fact, inviting the notion of otherworldly populations, as the prominent Dutch scientist Christiaan Huygens pointed out in the late 1600s. “A man that is of Copernicus’ opinion, that this Earth of ours is a planet … like the rest of the planets, cannot but sometimes think that it’s not improbable that the rest of the planets have … their inhabitants too,” Huygens wrote in his New Conjectures Concerning the Planetary Worlds, Their Inhabitants and Productions.
A few years earlier, French science popularizer Bernard le Bovier de Fontenelle had surveyed the prospects for life in the solar system in his Conversations on the Plurality of Worlds, an imaginary dialog between a philosopher and an uneducated but intelligent woman known as the Marquise.
“It would be very strange that the Earth was as populated as it is, and the other planets weren’t at all,” the philosopher told the Marquise. Although he didn’t think people could live on the sun (if there were any, they’d be blinded by its brightness), he sided with those who envisioned inhabitants on other planets and even the moon.
“Just as there have been and still are a prodigious number of men foolish enough to worship the Moon, there are people on the Moon who worship the Earth,” he wrote.
From early modern times onward, discussion of aliens was not confined to science and philosophy. They also appeared in various works of fiction, providing plot devices that remain popular to the present day. Often authors used aliens as stand-ins for evil (or occasionally benevolent) humans to comment on current events. Modern science fiction about aliens frequently portrays them in the role of tyrants or monsters or victims, with parallels to real life (think Flash Gordon’s nemesis Ming the Merciless, a 1930s dictator, or the extraterrestrials of the 1980s film and TV show Alien Nation — immigrants encountering bigotry and discrimination). When humans look for aliens, it seems, they often imagine themselves.
Serious science While aliens thrived in fiction, though, serious scientific belief in extraterrestrials — at least nearby — diminished in the early 20th century, following late 19th century exuberance about possible life on Mars. Supposedly a network of lines interpreted as canals signified the presence of a sophisticated Martian civilization; its debunking (plus further knowledge about planetary environments) led to general agreement that finding intelligent life elsewhere in the solar system was not an intelligent bet. On the other hand, the universe had grown incredibly vaster than the early Copernicans had imagined. The sun had become just one of billions of stars in the Milky Way galaxy, which in turn was only one of billions of other similar galaxies, or “island universes.” Within a cosmos so expansive, alien enthusiasts concluded, the existence of other life somewhere seemed inevitable. In 1961, astronomer Frank Drake developed an equation to gauge the likelihood of extraterrestrial life’s existence; by the 1990s he estimated that 10,000 planets possessed advanced civilizations in the Milky Way alone, even before anybody really knew for sure that planets outside the solar system actually existed.
But now everybody does. In the space of the last two decades, conclusive evidence of exoplanets, now numbering in the thousands, has reconfigured the debate and sharpened Fermi’s original paradox. No one any longer doubts that planets are plentiful. But still there’s been not a peep from anyone living on them, despite years of aiming radio telescopes at the heavens in hope of detecting a signal in the static of interstellar space.
Maybe such signals are just too rare or too weak for human instruments to detect. Or possibly some cosmic conspiracy is at work to prevent civilizations from communicating — or arising in the first place. Or perhaps civilizations that do arise are eradicated before they have a chance to communicate.
Or maybe the alien invasion has merely been delayed. Fermi’s paradox implicitly assumes that other civilizations have been around long enough to develop galactic transportation systems. After all, the universe, born in the Big Bang 13.8 billion years ago, is three times as old as the Earth. So most analyses assume that alien civilizations had a head start and would be advanced enough by now to go wherever they wanted to. But a new paper suggests that livable galactic neighborhoods may have developed only relatively recently. In a young, smaller and more crowded universe, cataclysmic explosions known as gamma-ray bursts may have effectively sterilized otherwise habitable planets, Tsvi Piran and collaborators suggest in a paper published in February in Physical Review Letters.
A planet near the core of a galaxy would be especially susceptible to gamma-ray catastrophes. And in a young universe, planets closer to the galactic edge (like Earth) would also be in danger from gamma-ray bursts in neighboring satellite galaxies. Only as the expansion of the universe began to accelerate — not so long before the birth of the Earth — would galaxies grow far enough apart to provide safety zones for life.
“The accelerated expansion induced by a cosmological constant slows the growth of cosmic structures, and increases the mean inter-galaxy separation,” Piran and colleagues write. “This reduces the number of nearby satellites likely to host catastrophic” gamma-ray bursts. So most alien civilizations would have begun to flourish not much before Earth’s did; those aliens may now be wondering why nobody has visited them.
Still, the radio silence from the sky makes some scientists wonder whether today’s optimism about ET’s existence will go the way of the Martian canal society. From one sobering perspective, aliens aren’t sending messages because few planets remain habitable long enough for life to develop an intelligent civilization. One study questions, for instance, how likely it is that life, once initiated on any planet, would shape its environment sufficiently well to provide for lasting bio-security.
In fact, that study finds, a wet, rocky planet just the right distance from a star — in the Goldilocks zone — might not remain habitable for long. Atmospheric and geochemical processes would typically drive either rapid warming (producing an uninhabitable planet like Venus) or quick cooling, freezing water and leaving the planet too cold and dry for life to survive, Aditya Chopra and Charles Lineweaver conclude in a recent issue of Astrobiology. Only if life itself alters these processes can it maintain a long-term home suitable for developing intelligence.
“Feedback between life and environment may play the dominant role in maintaining the habitability of the few rocky planets in which life has been able to evolve,” wrote Chopra and Lineweaver, both of the Australian National University in Canberra.
Yet even given such analyses — based on a vastly deeper grasp on astronomy and cosmology than medieval scholars possessed — whether real aliens exist remains one of those questions that science cannot now answer. It’s much like other profound questions also explored in medieval times: What is the universe made of? Is it eternal? Today’s scientists may be closer (or not) to answering those questions than were their medieval counterparts. Nevertheless the answers are not yet in hand.
Maybe we’ll just have to pose those questions to the aliens, if they exist, and are ever willing to communicate. And if those aliens do arrive, and provide the answers, humankind may well discover how medieval its understanding of the cosmos still is. Or perhaps the aliens will be equally clueless about nature’s deepest mysteries. As Fontenelle’s philosopher told the Marquise: “There’s no indication that we’re the only foolish species in the universe. Ignorance is quite naturally a widespread thing.”
