Connect with us

Science

Event Horizon Telescope captures new view of black hole in polarized light

Published

on

Two years ago, the Event Horizon Telescope (EHT) made headlines with its announcement of the first direct image of a black hole. Science magazine named the image its Breakthrough of the Year. Now the EHT collaboration is back with another groundbreaking result: a new image of the same black hole, this time showing how it looks in polarized light. The ability to measure that polarization for the first time—a signature of magnetic fields at the black hole’s edge—is expected to yield fresh insight into how black holes gobble up matter and emit powerful jets from their cores. The new findings were described in three papers published in The Astrophysical Journal Letters.

“This work is a major milestone: the polarization of light carries information that allows us to better understand the physics behind the image we saw in April 2019, which was not possible before,” said co-author Iván Martí-Vidal, coordinator of the EHT Polarimetry Working Group and a researcher at the University of Valencia, Spain. “Unveiling this new polarized-light image required years of work due to the complex techniques involved in obtaining and analyzing the data.”

As Ars’ John Timmer reported back in 2019:

The Event Horizon Telescope isn’t a telescope in the traditional sense. Instead, it’s a collection of telescopes scattered around the globe. In its current iteration, it includes hardware from Hawaii to Europe, and from the South Pole to Greenland, though not all of these were active during the initial observations. The telescope is created by a process called interferometry, which uses light captured at different locations to build an image with a resolution similar to that of a telescope the size of the most distant locations.

Interferometry has been used for facilities like ALMA, the Atacama Large Millimeter/submillimeter Array, where telescopes can be spread across 16km of desert. In theory, there’s no upper limit on the size of the array, but there are several challenges. To know which photons originated at the same time at the source, you need very precise location and timing information on each of the sites. And you still have to gather sufficient photons in order to see anything. In general, that means atomic clocks (which had to be installed at many of the locations) and extremely precise GPS measurements built up over time. For the Event Horizon Telescope, the large collecting area of ALMA, combined with choosing a wavelength where supermassive black holes are very bright, ensured sufficient photons. The net result is a telescope that can do the equivalent of reading the year stamped on a coin in Los Angeles from New York City—assuming the coin was glowing at radio wavelengths. There’s no way we can do better without relying on hardware that’s not located on Earth.

Those multiple imaging methods resulted in the first direct image ever taken of a black hole at the center of an elliptical galaxy. Located in the constellation of Virgo, some 55 million light years away, the galaxy is called Messier 87 (M87). The collaboration’s findings were published on April 10, 2019 in six different papers featured in The Astrophysical Journal Letters. It’s a feat that would have been impossible a mere generation ago, made possible by technological breakthroughs, innovative new algorithms, and of course, connecting several of the world’s best radio observatories. The image confirmed that the object at the center of M87 is indeed a black hole.

The EHT captured photons trapped in orbit around the black hole, swirling around at near the speed of light, creating a bright ring around it. From this, astronomers were able to deduce that the black hole is spinning clockwise. The imaging also revealed the shadow of the black hole, a dark central region within the ring. That shadow is as close as astronomers can get to taking a picture of the actual black hole, from which light cannot escape once it crosses the event horizon. And just as the size of the event horizon is proportional to the black hole’s mass, so too is the black hole’s shadow: the more massive the black hole, the larger the shadow. (The M87 black hole’s mass is 6.5 billion times that of our Sun.) It was a stunning confirmation of the general theory of relativity, showing that those predictions hold up even in extreme gravitational environments.

However, what was lacking was insight into the process behind the powerful twin jets produced by the black hole gobbling up matter, ejecting a portion of the material falling into it away at nearly light speed. (The black hole at the center of our Milky Way is less ravenous, i.e., relatively quiet, compared to M87’s black hole.) For example, astronomers don’t yet agree about how those jets get accelerated to such high speeds. These new results place additional constraints around the various competing theories, narrowing the possibilities.

In much the same way that polarized sunglasses reduce glare from bright surfaces, the polarized light around a black hole provides a sharper view of the region around it. In this case, the polarization of light isn’t due to special filters (like the lenses in sunglasses) but the presence of magnetic fields in the hot region of space surrounding the black hole. That polarization enables astronomers to map the magnetic field lines at the inner edge and to study the interaction between matter flowing in and being blown outward.

“The observations suggest that the magnetic fields at the black hole’s edge are strong enough to push back on the hot gas and help it resist gravity’s pull. Only the gas that slips through the field can spiral inwards to the event horizon,” said co-author Jason Dexter of the University of Colorado Boulder, who is also coordinator of the EHT Theory Working Group. That means that only theoretical models that incorporate the feature of a strongly magnetized gas accurately describe what the EHT collaboration has observed.

DOI: “First M87 Event Horizon Telescope Results VII: polarization of the ring,” Astrophysical Journal Letters, 2021. 10.3847/2041-8213/abe71d.

DOI: “First M87 Event Horizon Telescope Results VIII: Magnetic Field Structure Near The Event Horizon,” Astrophysical Journal Letters, 2021. 10.3847/2041-8213/abe4de.

DOI: “Polarimetric properties of Event Horizon Telescope targets from ALMA,” Astrophysical Journal Letters, 2021. 10.3847/2041-8213/abee6a (About DOIs).

Listing image by EHT Collaboration

Continue Reading

Science

Early omicron data finds vaccine protection stumbles—but recovers with boosters

Published

on

Enlarge / Pedestrians walk in front of a COVID-19 vaccination site in Brooklyn, New York, on Nov. 19, 2021.

The first batch of preliminary laboratory data on the omicron coronavirus variant has come out, and the results are largely what health experts have anticipated: protective antibodies from two doses of the Pfizer-BioNTech vaccine are considerably less effective at thwarting the new variant than older versions of the virus. However, antibody potency appears to rebound to fight omicron after a booster dose.

The results suggest that people who have only two doses of the mRNA vaccine may not be protected from infection but would likely remain protected from severe disease. The findings also suggest that maintaining high levels of protection against omicron will require a booster dose of the current vaccines—or even an omicron-specific shot in the future.

The top-line findings and conclusions come from three separate sets of laboratory experiments—all of which are extremely preliminary, involve small sample numbers, and have not been peer-reviewed or published in scientific journals.

Pfizer and BioNTech data

The freshest data comes from preliminary results reported online Wednesday morning by Pfizer and BioNTech. The companies conducted laboratory experiments that pitted antibodies from the blood serum of vaccinated people against a pseudovirus engineered to mimic the omicron variant. The experiments specifically measured the activity of neutralizing antibodies, which are a subset of antibodies that can bind to SARS-CoV-2 virus particles in such a way that the virus is prevented from entering human cells. Neutralizing antibodies are the most potent at preventing infection, but the immune system also produces a diverse array of other antibodies that can help fight an infection. Additionally, the immune system has protective cell-based responses that are not captured in these types of laboratory experiments.

In experiments using the blood sera of people fully vaccinated with the Pfizer-BioNTech vaccine (two doses), neutralizing antibody levels fell 25-fold against the omicron-mimicking pseudovirus compared with levels seen against a pseudovirus mimicking an older version of the virus. But when the companies looked at blood sera from fully vaccinated people one month after they received a vaccine booster shot (three doses), neutralizing antibody levels rebounded 25-fold against omicron, making them comparable to neutralizing antibody levels seen against older versions of the virus.

“Although two doses of the vaccine may still offer protection against severe disease caused by the omicron strain, it’s clear from these preliminary data that protection is improved with a third dose of our vaccine,” Pfizer CEO Albert Bourla said in a statement. “Ensuring as many people as possible are fully vaccinated with the first two-dose series and a booster remains the best course of action to prevent the spread of COVID-19.”

The companies also reported that they are still working on an omicron-specific vaccine dose in case it is needed. The timeline for the first batches to be available is still within 100 days from now, the companies said.

Continue Reading

Science

Some “true believers” in space settlement are starting to make it happen

Published

on

Enlarge / Dylan Taylor listens as former astronaut Nicole Stott speaks during a Space For Humanity event in early 2020. The organization’s executive director, Rachel Lyons, is in the background.

Editor’s Note: This is the first in an occasional series of profiles of people helping to lead the commercial space industry, which NASA Deputy Administrator Pam Melroy has called “the envy of the world.” Everyone knows who Elon Musk and Jeff Bezos are. But there are many other people working to usher in a future in which spaceflight is sustainable and economic activity in space is profitable. These are some of their stories.

Dylan Taylor seemed almost in shock when we spoke by telephone in late October.

“This,” he said, his voice breaking, “has been a dream of mine for almost my entire life.”

Taylor had called to say the crew lineup for the third human flight of Blue Origin’s New Shepard flight had been finalized, and he was among four paying passengers. The flight, launching on Saturday from West Texas, will include higher-profile crew members. Notably, Good Morning America co-anchor Michael Strahan and Laura Shepard Churchley, the eldest daughter of Alan Shepard, are both flying as guests alongside Taylor, Evan Dick, Lane Bess, and Cameron Bess.

But for commercial space, Taylor is one of the most consequential space entrepreneurs yet to go to space, perhaps second only to Blue Origin founder Jeff Bezos and Virgin Galactic’s Sir Richard Branson, who both flew earlier this summer.

Flying on New Shepard this week is an important step in Taylor’s personal journey, and he hopes to share the experience with others. In 2017, he founded Space For Humanity, which is buying seats on New Shepard and Virgin Galactic’s VSS Unity spacecraft to create opportunities for “citizen astronauts.” The goal is to sponsor people from all over the world to go to space, experience the overview effect, and return to Earth to share it with their communities.

But his impact goes far beyond simply spreading awareness of spaceflight. In recent years, Taylor has had an increasingly important, if quiet, influence on the development of commercial space. He is chairman and founder of Voyager Space Holdings, which has built a portfolio of new space companies. One small Voyager company, Nanoracks, recently won a $160 million contract from NASA to begin developing a commercial space station in low Earth orbit.

For Taylor, this marked a hugely validating moment. He counts himself as one of “Gerry’s kids,” a cohort of idealistic space cadets who believe humans should settle space and that the best place to do so is in massive O’Neill cylinders—first theorized by physicist Gerry O’Neill—orbiting Earth and the Moon. Privately developed space stations represent a concrete first step toward this goal.

“I’m a true believer,” Taylor, 51, said. “If the end state is O’Neillian, the way my brain works is—what are the obstacles and what are the constraints, and how do we overcome them?”

There are already plenty of companies building rockets, he believes. So the biggest constraint now is the development of economic activity in space, giving humans a purpose to go there.

His answer ultimately has come in the form of Voyager, which he describes as a “sustainable and benevolent” operating company. It seeks to acquire promising small space companies focusing on in-space activities, such as habitats, mitigating orbital debris, and satellite servicing. Taylor looks at the new space industry and sees a lot of companies struggling, even though they have good ideas. Maybe they have capital constraints or can’t scale easily.

Through Voyager, Taylor wants space entrepreneurs to do what they do best: innovate. So Voyager acquires their companies, provides the funding they need to scale, and helps with the business side of things. In this way, Taylor might best be seen as someone who helps promising new space companies survive the “valley of death” most startups go through.

Getting into business

Taylor grew up in Idaho and is the son of a metallurgical engineering professor at the University of Idaho. He was an avid baseball player and enjoyed the social side of school more than academics. Still, he got good enough grades to go to almost any school in the country, eventually choosing the University of Arizona because he liked the sunshine. Taylor followed in his father’s footsteps and studied engineering, but he knew he wanted to eventually become a lawyer or businessman.

After graduating from college in 1993, Taylor took a job with a Switzerland-based electronics company, Saia-Burgess, in Chicago. He got in at the right time as just one of a handful of employees in North America. Seven years later, Taylor was a general manager at a company with a few thousand people in the United States. By the turn of the century, he was not yet 30 years old, and he was already a sharp young engineer who had earned an MBA and understood the fundamentals of global business.

At the time, Saia-Burgess moved its North American operations to Troy, Michigan, to be closer to its automotive customers. Taylor disliked the new location and moved back to Chicago to be with his friends and a girlfriend who became his wife. He took a job with LaSalle Partners, which offered investment banking and real estate services. Taylor received several promotions and eventually hired on with Colliers International, a private equity firm in Toronto, in 2009.

Again, he caught a company on the upswing. Over the next six years, Colliers’ annual revenue increased from $400 million to about $3 billion. Taylor also rose to become CEO of the Americas. In 2015, the company went public, and Taylor owned “a significant part” of it. “That was a pretty life-changing event for me,” he said.

But then, in 2019, Colliers fired Taylor for “insider trading.” He was working as CEO of its real estate services division. This could have been another life-changing event, albeit not in a good way. A subsequent investigation, however, found there had been no improper dealings. “Long story short, I had decided to leave,” Taylor said. “And then as I was leaving, there was a disagreement that was completely resolved.” Taylor and Colliers issued a joint statement, amicably settling the matter.

Taylor had wanted to leave Colliers after about a quarter-century in the business world because he was increasingly interested and passionate about spaceflight. He had first started to engage in space as far back as 2007, when he met Space Adventurers co-founder Eric Anderson at the World Economic Forum in Davos, Switzerland.

By then, Taylor was already financially set for life. “I’m sitting at the World Economic Forum, and supposedly you’re king of the world,” he said. “You have more money than you need. Yet, you’re not feeling fulfilled. I started to think about my purpose.” Taylor soon realized that his purpose was to help humanity extend its reach into space to become a spacefaring species. Taylor ended up investing in Anderson’s ventures, and the aerospace engineer began introducing Taylor to his network.

Continue Reading

Science

Anime convention of 53K is first US case study for omicron spread, CDC says

Published

on

Enlarge / Costumed attendees take a break during Anime NYC at the Jacob K. Javits Convention Center in New York City on November 20, 2021. Anime NYC is an annual three-day anime convention held in New York City.

An anime convention held in New York City last month may inadvertently offer the US its first case study on the spread of the omicron coronavirus variant, according to the Centers for Disease Control and Prevention.

Fifty-three thousand anime fans from all 50 states, the District of Columbia, Puerto Rico, and 27 other countries traveled to New York City for the Anime NYC convention, which ran from November 19 and 21 in the city’s Javits Center. Organizers reported afterward that they were overwhelmed by the large attendance and struggled with packed rooms and crowding—conditions ideal for coronavirus transmission.

Last week, officials in Minnesota reported that a resident tested positive for the omicron variant after attending the convention. At the time, it was only the second omicron case detected in the US. But since then, officials have identified cases in at least 18 other US states, as well as over 50 countries worldwide.

The discovery of omicron at a large, tightly packed event with far-flung travelers is concerning. The variant is thought to be ultratransmissible. Preliminary reports from South Africa suggest omicron may spread more than twice as quickly as the already hypertransmissible delta variant. In such a crowded convention, omicron could swiftly spread among attendees and be carried back to home states and countries for further spread.

Spotting spread

Omicron is, in all likelihood, rapidly escalating in the US. Despite this, health officials have been relatively slow in detecting the variant. Genomic surveillance of variants is patchy and limited across states, though it has improved since the pandemic began. Another factor working against the country is the still extremely high levels of delta transmission. Any relatively small rise in omicron cases could easily be washed out by the massive delta wave.

But the anime convention provides a specific source of transmission that health investigators can use to get a clearer look at how omicron is spreading. The CDC has teamed up with the Minnesota and New York City health departments to retrace omicron’s steps through the massive event.

In a press briefing Tuesday, CDC director Rochelle Walensky said that the CDC has reached out to all states, territories, and countries with residents who attended the convention and hopes to reach all of the reported 53,000 attendees. So far, health officials have contacted more than 35,000 of them.

“Data from this investigation will likely provide some of the earliest looks in this country on the transmissibility of the variant,” Walensky said during the briefing.

Contact tracers will likely have their work cut out for them. On December 4, Connecticut announced that it had detected its first omicron case in a man in his 60s. The man had a family member who had tested positive for COVID-19 days earlier after returning from the anime convention in New York.

In a New York Times article published December 5, the Minnesota man first found to have an omicron infection after the convention said that roughly half of the 30 vaccinated people he recalls socializing with have tested positive. He told the paper that he had spent his time in New York attending discussion panels at the convention, chatting with strangers, and singing karaoke.

Continue Reading

Trending