Physicists observationally confirm Hawking’s black hole theorem for the first time

There are certain rules that even the most extreme objects in the universe must obey. A central law for black holes predicts that the area of their event horizons — the boundary beyond which nothing can ever escape — should never shrink. This law is Hawking’s area theorem, named after physicist Stephen Hawking, who derived the theorem in 1971.

Fifty years later, physicists at MIT and elsewhere have now confirmed Hawking’s area theorem for the first time, using observations of gravitational waves. Their results appear today in Physical Review Letters.

In the study, the researchers take a closer look at GW150914, the first gravitational wave signal detected by the Laser Interferometer Gravitational-wave Observatory (LIGO), in 2015. The signal was a product of two inspiraling black holes that generated a new black hole, along with a huge amount of energy that rippled across space-time as gravitational waves.

If Hawking’s area theorem holds, then the horizon area of the new black hole should not be smaller than the total horizon area of its parent black holes. In the new study, the physicists reanalyzed the signal from GW150914 before and after the cosmic collision and found that indeed, the total event horizon area did not decrease after the merger — a result that they report with 95 percent confidence.

Their findings mark the first direct observational confirmation of Hawking’s area theorem, which has been proven mathematically but never observed in nature until now. The team plans to test future gravitational-wave signals to see if they might further confirm Hawking’s theorem or be a sign of new, law-bending physics.

“It is possible that there’s a zoo of different compact objects, and while some of them are the black holes that follow Einstein and Hawking’s laws, others may be slightly different beasts,” says lead author Maximiliano Isi, a NASA Einstein Postdoctoral Fellow in MIT’s Kavli Institute for Astrophysics and Space Research. “So, it’s not like you do this test once and it’s over. You do this once, and it’s the beginning.”

Isi’s co-authors on the paper are Will Farr of Stony Brook University and the Flatiron Institute’s Center for Computational Astrophysics, Matthew Giesler of Cornell University, Mark Scheel of Caltech, and Saul Teukolsky of Cornell University and Caltech.

An age of insights

In 1971, Stephen Hawking proposed the area theorem, which set off a series of fundamental insights about black hole mechanics. The theorem predicts that the total area of a black hole’s event horizon — and all black holes in the universe, for that matter — should never decrease. The statement was a curious parallel of the second law of thermodynamics, which states that the entropy, or degree of disorder within an object, should also never decrease.

The similarity between the two theories suggested that black holes could behave as thermal, heat-emitting objects — a confounding proposition, as black holes by their very nature were thought to never let energy escape, or radiate. Hawking eventually squared the two ideas in 1974, showing that black holes could have entropy and emit radiation over very long timescales if their quantum effects were taken into account. This phenomenon was dubbed “Hawking radiation” and remains one of the most fundamental revelations about black holes.

“It all started with Hawking’s realization that the total horizon area in black holes can never go down,” Isi says. “The area law encapsulates a golden age in the ’70s where all these insights were being produced.”

Hawking and others have since shown that the area theorem works out mathematically, but there had been no way to check it against nature until LIGO’s first detection of gravitational waves.

Hawking, on hearing of the result, quickly contacted LIGO co-founder Kip Thorne, the Feynman Professor of Theoretical Physics at Caltech. His question: Could the detection confirm the area theorem?

At the time, researchers did not have the ability to pick out the necessary information within the signal, before and after the merger, to determine whether the final horizon area did not decrease, as Hawking’s theorem would assume. It wasn’t until several years later, and the development of a technique by Isi and his colleagues, when testing the area law became feasible.

Before and after

In 2019, Isi and his colleagues developed a technique to extract the reverberations immediately following GW150914’s peak — the moment when the two parent black holes collided to form a new black hole. The team used the technique to pick out specific frequencies, or tones of the otherwise noisy aftermath, that they could use to calculate the final black hole’s mass and spin.

A black hole’s mass and spin are directly related to the area of its event horizon, and Thorne, recalling Hawking’s query, approached them with a follow-up: Could they use the same technique to compare the signal before and after the merger, and confirm the area theorem?

The researchers took on the challenge, and again split the GW150914 signal at its peak. They developed a model to analyze the signal before the peak, corresponding to the two inspiraling black holes, and to identify the mass and spin of both black holes before they merged. From these estimates, they calculated their total horizon areas — an estimate roughly equal to about 235,000 square kilometers, or roughly nine times the area of Massachusetts.

They then used their previous technique to extract the “ringdown,” or reverberations of the newly formed black hole, from which they calculated its mass and spin, and ultimately its horizon area, which they found was equivalent to 367,000 square kilometers (approximately 13 times the Bay State’s area).

“The data show with overwhelming confidence that the horizon area increased after the merger, and that the area law is satisfied with very high probability,” Isi says. “It was a relief that our result does agree with the paradigm that we expect, and does confirm our understanding of these complicated black hole mergers.”

The team plans to further test Hawking’s area theorem, and other longstanding theories of black hole mechanics, using data from LIGO and Virgo, its counterpart in Italy.

“It’s encouraging that we can think in new, creative ways about gravitational-wave data, and reach questions we thought we couldn’t before,” Isi says. “We can keep teasing out pieces of information that speak directly to the pillars of what we think we understand. One day, this data may reveal something we didn’t expect.”

This research was supported, in part, by NASA, the Simons Foundation, and the National Science Foundation.

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Giving robots better moves

For most people, the task of identifying an object, picking it up, and placing it somewhere else is trivial. For robots, it requires the latest in machine intelligence and robotic manipulation.

That’s what MIT spinoff RightHand Robotics has incorporated into its robotic piece-picking systems, which combine unique gripper designs with artificial intelligence and machine vision to help companies sort products and get orders out the door.

“If you buy something at the store, you push the cart down the aisle and pick it yourself. When you order online, there is an equivalent operation inside a fulfillment center,” says RightHand Robotics co-founder Lael Odhner ’04, SM ’06, PhD ’09. “The retailer typically needs to pick up single items, run them through a scanner, and put them into a sorter or conveyor belt to complete the order. It sounds easy until you imagine tens of thousands of orders a day and more than 100,000 unique products stored in a facility the size of 10 or 20 football fields, with the delivery expectation clock ticking.”

RightHand Robotics is helping companies respond to two broad trends that have transformed retail operations. One is the explosion of e-commerce, which only accelerated during the Covid-19 pandemic. The other is a shift to just-in-time inventory fulfillment, in which pharmacies, grocery stores, and apparel companies restock items based on what’s been purchased that day or week to improve efficiency.

The robot fleet also collects data that help RightHand Robotics improve its system over time and enable it to learn new skills, such as more gentle or precise placement. Process and performance data feed into the company’s fleet management software, which can help customers understand how their inventory moves through the warehouse and identify bottlenecks or quality problems.

“The idea is that rather than looking at just the performance of a single operation, e-commerce firms can modify or overhaul the operational flow throughout the warehouse,” Odhner says. “The goal is to eliminate variability as far upstream as is feasible, making a simpler, streamlined process.”

Pushing the limit

Odhner completed his PhD in the lab of Harry Asada, MIT’s Ford Professor of Engineering in the Department of Mechanical Engineering, who Odhner says encouraged students to develop a broad familiarity with robotics research. Colleagues also frequently shared their work in seminars, giving Odhner a well-rounded view of the field.

“Asada is a very well-known robotics researcher, and his early work, as well as the projects I worked on with him, are very much fundamental to what we’re doing at RightHand Robotics,” Odhner says.

In 2009, Odhner was part of the winning team in the DARPA Autonomous Robotic and Manipulation Challenge. Many of the competing teams had MIT connections, and the entire program was eventually run by former MIT associate professor Gill Pratt. After making the semifinals of the MIT 100K competition in 2013 as “Manus Robotics,” the team was introduced to Mick Mountz ’87, founder of Kiva Systems (later acquired by Amazon), who encouraged the team to look at applications in supply chain and logistics.

Today, a significant amount of RightHand Robotics employees and leadership come from MIT. MIT researchers also accounted for many early customers, buying components Odhner’s team had invented during the DARPA program.

“Generally, we’ve been in such close proximity to MIT that it’s hard to avoid circling back there,” Odhner says. “It’s kind of a family. You don’t ever really leave MIT.”

At the core of the RightH and Robotics solution is the idea of using machine vision and intelligent grippers to make piece-picking robots more adaptable. The combination also limits the amount of training needed to run the robots, equipping each machine with what the company equates to hand-eye coordination.

“The technical part of what we do is we have to look at an unstructured presentation of consumer goods and semantically understand what’s in there,” Odhner says.

RightHand Robotics also utilizes an end-of-arm tool that combines suction with novel underactuated fingers, which Odhner says gives the robots more flexibility than robots relying solely on suction cups or simple pinching grippers.

“Sometimes it actually helps you to have passive degrees of freedom in your hand, passive motions that it can make and can’t actively control,” Odhner says of the robots. “Very often those simplify the control task. They take problems from being heavily over-constrained and make them tractable to run through a motion planning algorithm.”

The data the robots collect are also used to improve reliability over time and shed light on warehouse operations for customers.

“We can give people insights into their inventory, insights into how they’re storing their inventory, how they’re structuring tasks both upstream and downstream of any picking we’re doing,” Odhner says. “We have very good insight as to what may be a source of future problems, and we can feed that back to customers.”

Odhner notes that warehouse fulfillment could grow to be a much larger industry if throughput were improved.

“As consumers increasingly value the option of shopping online, more and more items need to get into a growing number of ‘virtual’ carts. The availability of people near order fulfillment centers tends to be a limiting factor for e-commerce growth. All of that is really indicative of a massive economic inefficiency, and that’s essentially what we’re trying to address,” Odhner says. “We are taking the least engaging tasks in the warehouse — things like sorter induction, where you’re just picking, scanning, and putting something on a belt all day long — and we’re working to automate those tasks to the point where you can take your people and you can direct them to things that are going to be more directly felt by the customer.”

Odhner also says more automated fulfillment centers offer improved measures to protect worker health and safety, such as ergonomic stations where goods are brought to workers for specialized tasks and increased social distancing. Rather than reducing the number of people employed in a warehouse, he says, “Ultimately, what you want is a system with people working in roles like quality control, overseeing the robots.”

Robots made easy

This year, the company is introducing the third version of its picking robot, which ships with standardized integration and safety features in an attempt to make deploying piece-picking robots easier for warehouse operators.

“People may not necessarily grasp the enormity of our progress in productizing this autonomous system, in terms of ease of integration, configuration, safety, and reliability, but it is huge because it means that our robot systems can be drop-shipped pretty much worldwide and get up and running with minimal customization,” Odhner says. “There is no reason why this can’t just come in a box or on a pallet and be set up by anyone. That’s our big vision.”

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Anders Sejr Hansen awarded prestigious Pew-Stewart Grant for Cancer Research

Anders Sejr Hansen, assistant professor of biological engineering at MIT, has been named a Pew-Stewart Scholar for Cancer Research for 2021. The Pew-Stewart Scholars Program for Cancer Research is a national initiative designed to support promising early-career scientists whose research will accelerate discovery and advance progress toward a cure for cancer.

The Hansen Lab will investigate how genetic elements, known as enhancers, control the expression of genes in cancer. Notably, enhancers can be quite far away from the genes they control. For example, the enhancers that regulate c-Myc, a gene commonly expressed in high levels in cancer, are amplified in lung and endometrial cancers. However, it is not well understood how having more copies of the enhancer drives the uptick in c-Myc expression.

Using a combination of single-molecule and super-resolution live-cell imaging methods and gene-editing tools, the lab will examine how long-range DNA loops are formed to promote functional interactions between enhancers and their target genes and how that drives their gene expression. This work will provide visual and real-time confirmation on how enhancers communicate with faraway genes and ultimately identify new therapeutic approaches to treat cancers driven by the overexpression of c-Myc.

“We are thrilled to receive this reward and honored to become a part of the Pew-Stewart Scholars in Cancer Research Program” says Hansen. “With the support of the Pew-Stewart Program, we will develop new super-resolution microscopy techniques to follow how enhancers communicate with oncogenes inside living cells at unprecedented spatiotemporal precision. Ultimately, we hope to use this new platform to understand the molecular mechanisms, and to identify molecular Achilles’ heels that we can target therapeutically in cancer”

Hansen joined MIT as an assistant professor in the Department of Biological Engineering in early 2020. He obtained his undergraduate and master’s degrees in chemistry at Oxford University in 2010 and received his PhD in chemistry and chemical biology from Harvard University in 2015. He worked with Erin O’Shea, applying systems biology approaches to understand how cells can encode and transmit information in the dynamics of transcription factor activation. For his postdoc at the University of California at Berkeley with Robert Tjian and Xavier Darzacq, Anders developed new imaging approaches for dissecting the dynamics of 3D genome organization with single-molecule resolution in living cells. 

In line with The Alexander and Margaret Stewart Trust’s mission to invest in innovative, cutting-edge cancer research that may accelerate and advance progress toward a cure for cancer, applications are from nominees conducting cancer research. The Pew-Stewart Scholars Program for Cancer Research is distinct from the Pew Scholars Program. It follows a different but parallel set of guidelines and procedures for nominating an applicant whose research is related to cancer. The award provides $300,000 in flexible support — $75,000 per year for four years.

Earlier this year, Anders was also awarded a grant from The G. Harold and Leila Y. Mathers Charitable Foundation to recognize innovative translational research.

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New approach could change how we track extreme air pollution events

When extreme and dangerous air pollution events strike and blanket the air with hazardous levels of pollution, it causes a major threat to public health and safety. It’s also exceedingly challenging to monitor. The pollutants move quickly through the atmosphere, and can undergo chemical transformations from one form to another, leaving it difficult to predict the level of human exposure. 

In the United States, the primary sources of outdoor air-quality data are from ground-based, government-regulated air-quality monitoring systems that measure pollutants such as ozone and particulate matter. Due to the high cost of these high-performing systems, the number of monitors measuring air quality across a geographic area is relatively sparse. As a result, these systems are not well-suited for monitoring extreme air-quality events, in which pollutant levels can be exceedingly high and variable over relatively short distances.  

In a new study, researchers in MIT’s Department of Civil and Environmental Engineering (CEE) demonstrate an alternate approach for monitoring extreme air-quality events with the use of low-cost sensor (LCS) networks. The work was carried out in mid-2018 on the Island of Hawaii, when the eruption of the Kilauea volcano filled the air with toxic sulfurous gases and particles (“volcanic smog” or “vog”). In response, the researchers developed and deployed a network of 40 low-cost sensors around the island to monitor the vog in real-time, which provided much higher resolution of localized levels of air pollution than existing air-quality measurements.
   
The paper, published in PNAS (Proceedings of the National Academy of Sciences), demonstrates the power of LCS networks in their ability to map pollution exposure and chemical transformation of air pollutants for air-quality research, public health monitoring, and emergency response. 

“There is a real demand for this kind of data and information about the air people are breathing,” says lead author Ben Crawford, assistant professor in the Department of Geography and Environmental Sciences at the University of Colorado at Denver, who deployed the sensors in Hawaii while a postdoc at MIT. “We need these low-cost sensors and the regulatory air monitoring systems to give us a better understanding of what's happening in the air we are breathing.”

Built for remote air quality sensing

The custom MIT sensors provided real-time levels of two toxic components of vog: sulfur dioxide gas (SO₂) and airborne particles, also known as particulate matter. The sensors are also solar powered, so they were deployed in remote areas of the island and communicated wirelessly over the cellular network. Because of the small size and low cost of the sensors, the researchers were able to place the sensors at different distances downwind of the volcano, to estimate the full distribution of pollution levels that people were exposed to in all areas around the island. 

“The data showed a wide range of pollutant exposure,” says co-author Jesse Kroll, professor in MIT’s departments of Civil and Environmental Engineering and Chemical Engineering. “Some residents were exposed to clean air the entire time, while people living in different points downwind of the volcano were exposed to different mixes of pollutants. This in itself isn’t surprising, but with the large number of sensors deployed we were able to quantify these exposures with much higher resolution than is normally possible.”

Capturing the pollutant exposure in the atmosphere around the island allowed the researchers to witness how the plume was chemically changing with time. “By having sensors at different distances downwind of the event we were able to estimate the rate at which one pollutant, sulfur dioxide, reacts in the atmosphere and converts into a different one, particulate matter,” adds Kroll. 

Prototypes of the sensors were originally developed as part of the CEE subject 1.091 (Traveling Research Environmental Experiences, or TREX), an annual undergraduate fieldwork project that takes students to Hawaii to conduct research over Independent Activities Period in January. Over the years, the students discovered limitations of LCS, especially their low accuracy relative to more expensive monitors. Prior to deployment, the researchers co-located all sensors with state monitoring stations run by the Hawaii Department of Health, providing an accurate calibration that was used throughout the entire eruption. 

Tracking smog and wildfires

Hawaii’s pristine environment, with its small number of pollutants, simple chemistry, and straightforward meteorology, was the ideal test environment to establish the viability of this approach. But this general approach could also be used for measuring urban smog and wildfires, according to the researchers. The low-cost, compact, solar-powered design of the sensors allows for the technology to be deployed in a number of configurations, allowing it to be linked to other air-quality data sources and technologies. 

People can use the information from sensors, together with other data sources, to make informed decisions about the health and safety of communities. It also provides an entryway into educating and bringing peace of mind to communities that live with the dangers and harmful effects from reoccurring extreme air-quality events.  

“One of the most exciting parts of this research project was using the sensors for both science and community engagement,” says Crawford. “Since we placed sensors at schools, we went into classrooms and talked about air quality and the ‘vog,’ and we had little demo sensors. It was a really fun way to engage with students about a global environmental issue that was relevant to them because they have lived through this eruption.”

Besides schools, the researchers also placed the MIT sensors at health clinics and some private residences. To provide public knowledge of Kilauea’s vog, the data were shared on a local website created by the researchers that continues to measure air quality on the island today. “These types of sensors provide a real opportunity for people and communities to engage in their own air-quality monitoring that's independent of government monitoring systems,” adds Crawford. 

Poor air quality is one of the largest environmental risk factors for premature mortality, heightened by extreme air-quality events that are becoming annual events in parts of the world. LCS networks provide a way forward for other communities to monitor air quality, especially resource-limited regions where air-quality monitoring systems are even more sparse or nonexistent.

“It's crucial from a public health perspective to improve our air quality worldwide. A key step in doing that is identifying the sources of the pollution, as well as the exact mix of pollutants that people are exposed to. Networks of low-cost sensors are great tools for providing such data,” says Kroll.  

Additional co-authors of the study include David Hagan, PhD ’20; Professor Colette Heald of MIT’s departments of Civil and Environmental Engineering and Earth, Atmospheric and Planetary Sciences; and collaborators from The Kohala Center, an independent, community-based center for research, conservation, and education.
 
The research study was funded by the U.S. Environmental Protection Agency (EPA), MIT’s Department of Civil and Environmental Engineering, and the Tata Center.

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Sweat-proof “smart skin” takes reliable vitals, even during workouts and spicy meals

MIT engineers and researchers in South Korea have developed a sweat-proof “electronic skin” — a conformable, sensor-embedded sticky patch that monitors a person’s health without malfunctioning or peeling away, even when a wearer is perspiring.

The patch is patterned with artificial sweat ducts, similar to pores in human skin, that the researchers etched through the material’s ultrathin layers. The pores perforate the patch in a kirigami-like pattern, similar to that of the Japanese paper-cutting art. The design ensures that sweat can escape through the patch, preventing skin irritation and damage to embedded sensors.

The kirigami design also helps the patch conform to human skin as it stretches and bends. This flexibility, paired with the material’s ability to withstand sweat, enables it to monitor a person’s health over long periods of time, which has not been possible with previous “e-skin” designs. The results, published today in Science Advances, are a step toward long-lasting smart skins that may track daily vitals or the progression skin cancer and other conditions.  

“With this conformable, breathable skin patch, there won’t be any sweat accumulation, wrong information, or detachment from the skin,” says Jeehwan Kim, associate professor of mechanical engineering at MIT. “We can provide wearable sensors that can do constant long-term monitoring.”

Kim’s co-authors include lead author and MIT postdoc Hanwool Yeon, and researchers in MIT’s departments of Mechanical Engineering and Materials Science and Engineering, and the Research Laboratory of Electronics, along with collaborators from cosmetics conglomerate Amorepacific and other institutions across South Korea.

A sweaty hurdle

Kim’s group specializes in fabricating flexible semiconductor films. The researchers have pioneered a technique called remote epitaxy, which involves growing ultrathin, high-quality semiconductor films on wafers at high temperature and selectively peeling away the films, which they can then combine and stack to form sensors far thinner and more flexible than conventional wafer-based designs.

Recently, their work drew the attention of the cosmetics company Amorepacific, which was interested in developing thin wearable tape to continuously monitor changes in skin. The company struck up a collaboration with Kim to fashion the group’s flexible semiconducting films into something that could be worn over long periods of time.

But the team soon came against a barrier that other e-skin designs have yet to clear: sweat. Most experimental designs embed sensors in sticky, polymer-based materials that are not very breathable. Other designs, made from woven nanofibers, can let air through, but not sweat. If an e-skin were to work over the long-term, Kim realized it would have to be permeable to not just vapor but also sweat.

“Sweat can accumulate between the e-skin and your skin, which could cause skin damage and sensor malfunctioning,” Kim says. “So we tried to address these two problems at the same time, by allowing sweat to permeate through electronic skin.”

Making the cut

For design inspiration, the researchers looked to human sweat pores. They found that the diameter of the average pore measures about 100 microns, and that pores are randomly distributed throughout skin. They ran some initial simulations to see how they might overlay and arrange artificial pores, in a way that would not block actual pores in human skin.

“Our simple idea is, if we provide artificial sweat ducts in electronic skin and make highly-permeable paths for the sweat, we may achieve long-term monitorability,” Yeon explains. 

They started with a periodic pattern of holes, each about the size of an actual sweat pore. They found that if pores were spaced close together, at a distance smaller than an average pore’s diameter, the pattern as a whole would efficiently permeate sweat. But they also found that if this simple hole pattern were etched through a thin film, the film was not very stretchable, and it broke easily when applied to skin.

The researchers found they could increase the strength and flexibility of the hole pattern by cutting thin channels between each hole, creating a pattern of repeating dumbbells, rather than simple holes, that relaxed strain, rather than concentrating it in one place. This pattern, when etched into a material, created a stretchable, kirigami-like effect.

“If you wrap a piece of paper over a ball, it’s not conformable,” Kim says. “But if you cut a kirigami pattern in the paper, it could conform. So we thought, why not connect the holes with a cut, to have kirigami-like conformability on the skin? At the same time we can permeate sweat.”

Following this rationale, the team fabricated an electronic skin from multiple functional layers, each which they etched with dumbbell-patterned pores. The skin’s layers comprise an ultrathin semiconductor-patterned array of sensors to monitor temperature, hydration, ultraviolet exposure, and mechanical strain. This sensor array is sandwiched between two thin protective films, all of which overlays a sticky polymer adhesive.

“The e-skin is like human skin — very stretchable and soft, and sweat can permeate through it,” Yeon says.

The researchers tested the e-skin by sticking it to a volunteer’s wrist and forehead. The volunteer wore the tape continuously over a week. Throughout this period, the new e-skin reliably measured his temperature, hydration levels, UV exposure, and pulse, even during sweat-inducing activities, such as running on a treadmill for 30 minutes and consuming a spicy meal.

The team’s design also conformed to skin, sticking to the volunteer’s forehead as he was asked to frown repeatedly while sweating profusely, compared with other e-skin designs that lacked sweat permeability, and easily detached from the skin.

Kim plans to improve the design’s strength and durability. While the tape is both permeable to sweat and highly conformable, thanks to its kirigami patterning, it’s this same patterning, paired with the tape’s ultrathin form, that makes it quite fragile to friction. As a result, volunteers had to wear a casing around the tape to protect it during activities such as showering.

“Because the e-skin is very soft, it can be physically damaged,” Yeon says. “We aim to improve the resilience of electronic skin.”

This research was supported by Amorepacific.

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Some brain disorders exhibit similar circuit malfunctions

Many neurodevelopmental disorders share similar symptoms, such as learning disabilities or attention deficits. A new study from MIT has uncovered a common neural mechanism for a type of cognitive impairment seen in some people with autism and schizophrenia, even though the genetic variations that produce the impairments are different for each condition.

In a study of mice, the researchers found that certain genes that are mutated or missing in some people with those disorders cause similar dysfunctions in a neural circuit in the thalamus. If scientists could develop drugs that target this circuit, they could be used to treat people who have different disorders with common behavioral symptoms, the researchers say.

“This study reveals a new circuit mechanism for cognitive impairment and points to a future direction for developing new therapeutics, by dividing patients into specific groups not by their behavioral profile, but by the underlying neurobiological mechanisms,” says Guoping Feng, the James W. and Patricia T. Poitras Professor in Brain and Cognitive Sciences at MIT, a member of the Broad Institute of Harvard and MIT, the associate director of the McGovern Institute for Brain Research at MIT, and the senior author of the new study.

Dheeraj Roy, a Warren Alpert Distinguished Scholar and a McGovern Fellow at the Broad Institute, and Ying Zhang, a postdoc at the McGovern Institute, are the lead authors of the paper, which appears today in Neuron.

Thalamic connections

The thalamus plays a key role in cognitive tasks such as memory formation and learning. Previous studies have shown that many of the gene variants linked to brain disorders such as autism and schizophrenia are highly expressed in the thalamus, suggesting that it may play a role in those disorders.

One such gene is called Ptchd1, which Feng has studied extensively. In boys, loss of this gene, which is carried on the X chromosome, can lead to attention deficits, hyperactivity, aggression, intellectual disability, and autism spectrum disorders.

In a study published in 2016, Feng and his colleagues showed that Ptchd1 exerts many of its effects in a part of the thalamus called the thalamic reticular nucleus (TRN). When the gene is knocked out in the TRN of mice, the mice show attention deficits and hyperactivity. However, that study did not find any role for the TRN in the learning disabilities also seen in people with mutations in Ptchd1.

In the new study, the researchers decided to look elsewhere in the thalamus to try to figure out how Ptchd1 loss might affect learning and memory. Another area they identified that highly expresses Ptchd1 is called the anterodorsal (AD) thalamus, a tiny region that is involved in spatial learning and communicates closely with the hippocampus.

Using novel techniques that allowed them to trace the connections between the AD thalamus and another brain region called the retrosplenial cortex (RSC), the researchers determined a key function of this circuit. They found that in mice, the AD-to-RSC circuit is essential for encoding fearful memories of a chamber in which they received a mild foot shock. It is also necessary for working memory, such as creating mental maps of physical spaces to help in decision-making.

The researchers found that a nearby part of the thalamus called the anteroventral (AV) thalamus also plays a role in this memory formation process: AV-to-RSC communication regulates the specificity of the encoded memory, which helps us distinguish this memory from others of similar nature.

“These experiments showed that two neighboring subdivisions in the thalamus contribute differentially to memory formation, which is not what we expected,” Roy says.

Circuit malfunction

Once the researchers discovered the roles of the AV and AD thalamic regions in memory formation, they began to investigate how this circuit is affected by loss of Ptchd1. When they knocked down expression of Ptchd1 in neurons of the AD thalamus, they found a striking deficit in memory encoding, for both fearful memories and working memory.

The researchers then did the same experiments with a series of four other genes — one that is linked with autism and three linked with schizophrenia. In all of these mice, they found that knocking down gene expression produced the same memory impairments. They also found that each of these knockdowns produced hyperexcitability in neurons of the AD thalamus.

These results are consistent with existing theories that learning occurs through the strengthening of synapses that occurs as a memory is formed, the researchers say.

“The dominant theory in the field is that when an animal is learning, these neurons have to fire more, and that increase correlates with how well you learn,” Zhang says. “Our simple idea was if a neuron fires too high at baseline, you may lack a learning-induced increase.”

The researchers demonstrated that each of the genes they studied affects different ion channels that influence neurons’ firing rates. The overall effect of each mutation is an increase in neuron excitability, which leads to the same circuit-level dysfunction and behavioral symptoms.

The researchers also showed that they could restore normal cognitive function in mice with these genetic mutations by artificially turning down hyperactivity in neurons of the AD thalamus. The approach they used, chemogenetics, is not yet approved for use in humans. However, it may be possible to target this circuit in other ways, the researchers say.

The findings lend support to the idea that grouping diseases by the circuit malfunctions that underlie them may help to identify potential drug targets that could help many patients, Feng says.

“There are so many genetic factors and environmental factors that can contribute to a particular disease, but in the end, it has to cause some type of neuronal change that affects a circuit or a few circuits involved in this behavior,” he says. “From a therapeutic point of view, in such cases you may not want to go after individual molecules because they may be unique to a very small percentage of patients, but at a higher level, at the cellular or circuit level, patients may have more commonalities.”

The research was funded by the Stanley Center at the Broad Institute, the Hock E. Tan and K. Lisa Yang Center for Autism Research at MIT, the James and Patricia Poitras Center for Psychiatric Disorders Research at MIT, and the National Institutes of Health BRAIN Initiative.

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The power of two

MIT’s Hockfield Court is bordered on the west by the ultramodern Stata Center, with its reflective, silver alcoves that jut off at odd angles, and on the east by Building 68, which is a simple, window-lined, cement rectangle. At first glance, Bonnie Berger’s mathematics lab in the Stata Center and Joey Davis’s biology lab in Building 68 are as different as the buildings that house them. And yet, a recent collaboration between these two labs shows how their disciplines complement each other. The partnership started when Ellen Zhong, a graduate student from the Computational and Systems Biology (CSB) Program, decided to use a computational pattern-recognition tool called a neural network to study the shapes of molecular machines. Three years later, Zhong’s project is letting scientists see patterns that run beneath the surface of their data, and deepening their understanding of the molecules that shape life.

Zhong’s work builds on a technique from the 1970s called cryo-electron microscopy (cryo-EM), which lets researchers take high-resolution images of frozen protein complexes. Over the past decade, better microscopes and cameras have led to a “resolution revolution” in cryo-EM that’s allowed scientists to see individual atoms within proteins. But, as good as these images are, they’re still only static snapshots. In reality, many of these molecular machines are constantly changing shape and composition as cells carry out their normal functions and adjust to new situations.

Along with former Berger lab member Tristan Belper, Zhong devised software called cryoDRGN. The tool uses neural nets to combine hundreds of thousands of cryo-EM images, and shows scientists the full range of three-dimensional conformations that protein complexes can take, letting them reconstruct the proteins’ motion as they carry out cellular functions. Understanding the range of shapes that protein complexes can take helps scientists develop drugs that block viruses from entering cells, study how pests kill crops, and even design custom proteins that can cure disease. Covid-19 vaccines, for example, work partly because they include a mutated version of the virus’s spike protein that’s stuck in its active conformation, so vaccinated people produce antibodies that block the virus from entering human cells. Scientists needed to understand the variety of shapes that spike proteins can take in order to figure out how to force spike into its active conformation.

Getting off the computer and into the lab

Zhong’s interest in computational biology goes back to 2011 when, as a chemical engineering undergrad at the University of Virginia, she worked with Professor Michael Shirts to simulate how proteins fold and unfold. After college, Zhong took her skills to a company called D. E. Shaw Research, where, as a scientific programmer, she took a computational approach to studying how proteins interact with small-molecule drugs.

“The research was very exciting,” Zhong says, “but all based on computer simulations. To really understand biological systems, you need to do experiments.”

This goal of combining computation with experimentation motivated Zhong to join MIT’s CSB PhD program, where students often work with multiple supervisors to blend computational work with bench work. Zhong “rotated” in both the Davis and Berger labs, then decided to combine the Davis lab’s goal of understanding how protein complexes form with the Berger lab’s expertise in machine learning and algorithms. Davis was interested in building up the computational side of his lab, so he welcomed the opportunity to co-supervise a student with Berger, who has a long history of collaborating with biologists.

Davis himself holds a dual bachelor’s degree in computer science and biological engineering, so he’s long believed in the power of combining complementary disciplines. “There are a lot of things you can learn about biology by looking in a microscope,” he says. “But as we start to ask more complicated questions about entire systems, we’re going to require computation to manage the high-dimensional data that come back.”

Before rotating in the Davis lab, Zhong had never performed bench work before — or even touched a pipette. She was fascinated to find how streamlined some very powerful molecular biology techniques can be. Still, Zhong realized that physical limitations mean that biology is much slower when it’s done at the bench instead of on a computer. “With computational research, you can automate experiments and run them super quickly, whereas in the wet lab, you only have two hands, so you can only do one experiment at a time,” she says.

Zhong says that synergizing the two different cultures of the Davis and Berger labs is helping her become a well-rounded, adaptable scientist. Working around experimentalists in the Davis lab has shown her how much labor goes into experimental results, and also helped her to understand the hurdles that scientists face at the bench. In the Berger lab, she enjoys having coworkers who understand the challenges of computer programming.

“The key challenge in collaborating across disciplines is understanding each other’s ‘languages,’” Berger says. “Students like Ellen are fortunate to be learning both biology and computing dialects simultaneously.”

Bringing in the community

Last spring revealed another reason for biologists to learn computational skills: these tools can be used anywhere there’s a computer and an internet connection. When the Covid-19 pandemic hit, Zhong’s colleagues in the Davis lab had to wind down their bench work for a few months, and many of them filled their time at home by using cryo-EM data that’s freely available online to help Zhong test her cryoDRGN software. The difficulty of understanding another discipline’s language quickly became apparent, and Zhong spent a lot of time teaching her colleagues to be programmers. Seeing the problems that nonprogrammers ran into when they used cryoDRGN was very informative, Zhong says, and helped her create a more user-friendly interface.

Although the paper announcing cryoDRGN was just published in February, the tool created a stir as soon as Zhong posted her code online, many months prior. The cryoDRGN team thinks this is because leveraging knowledge from two disciplines let them visualize the full range of structures that protein complexes can have, and that’s something researchers have wanted to do for a long time. For example, the cryoDRGN team recently collaborated with researchers from Harvard and Washington universities to study locomotion of the single-celled organism Chlamydomonas reinhardtii. The mechanisms they uncovered could shed light on human health conditions, like male infertility, that arise when cells lose the ability to move. The team is also using cryoDRGN to study the structure of the SARS-CoV-2 spike protein, which could help scientists design treatments and vaccines to fight coronaviruses.

Zhong, Berger, and Davis say they’re excited to continue using neural nets to improve cryo-EM analysis, and to extend their computational work to other aspects of biology. Davis cited mass spectrometry as “a ripe area to apply computation.” This technique can complement cryo-EM by showing researchers the identities of proteins, how many of them are bound together, and how cells have modified them.

“Collaborations between disciplines are the future,” Berger says. “Researchers focused on a single discipline can take it only so far with existing techniques. Shining a different lens on the problem is how advances can be made.”

Zhong says it’s not a bad way to spend a PhD, either. Asked what she’d say to incoming graduate students considering interdisciplinary projects, she says: “Definitely do it.”

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3 Questions: Anna Jagielska on printing artificial axons

Tens of millions of people worldwide suffer from neurodegenerative diseases such as Alzheimer’s, Parkinson’s, multiple sclerosis, and Lou Gehrig’s disease — but no effective treatments exist for these conditions.

Research Scientist Anna Jagielska of the MIT Department of Materials Science and Engineering thinks repairing the myelin wrapping around axons is key to preserving neurological function and slowing or stopping neurodegeneration. Her team, with support from the MIT Deshpande Center for Technological Innovation, the U.S. Department of Defense, Sanofi-Genzyme, and others, is developing artificial axons using advanced 3D printing, in the hopes of accelerating the discovery of drugs that stimulate myelin repair.

Q: What are the key barriers to developing drugs to treat neurodegenerative diseases?

A: The current lack of a predictive disease model and drug discovery tools results in more than 90 percent of neurological drug candidates failing in clinical trials. Having a predictive tool would save pharmaceutical companies time and costs in what is a long, multiyear process of drug development.

Our tools focus on myelin, and many neurological diseases are associated in some ways with damage or disorders of myelin, the protective sheath around axons. Each neuron has one long, thin fiber called an axon that transmits electrical impulses throughout the nervous system so we can move our limbs, see, and breathe. When the myelin coating around axons is damaged, a process known as demyelination, nerve conduction slows or is lost and axons can die. This can impact motor and cognitive functions, and lead to loss of vision and permanent disabilities. In many of these diseases, the body does not regenerate myelin sufficiently on its own. However, if a drug could stimulate the body to generate new myelin sheaths, a process known as remyelination, this could protect axons from dying and preserve their neurological function. We are developing artificial axons that mimic an environment where myelin grows and wraps around these axons as if they were in the brain. This tool would allow researchers to see how effectively different drugs spur the growth of myelin.

Q: How can artificial axons be potentially transformative for drug discovery?

A: Artificial axons fill an unmet need, providing the right tools to begin to address these neurological diseases. By supplying a sufficiently accurate representation of the neural environments for each of these illnesses, we’re hoping to help develop therapies that may alleviate them. Finding drugs that restore myelin would help slow the progression of illnesses like multiple sclerosis, which is marked by successive bouts of demyelination that lead to a progressive loss of nervous system function.

The early-stage development of such drugs is where this technology can be most helpful. The artificial axons mimic compliant brain cells and facilitate direct quantification of myelination. The 3D-printed platform balances the complexity of neurons’ biofidelic features with the simplicity of engineered polymer arrays to watch and quantify oligodendrocytes, the myelinating cells of the brain, as they grow, mature, and wrap myelin around the artificial axons, in the same way they would do so in the brain.

Our platform has many advantages over current tools. Traditional flat-tissue culture dishes made of hard, stiff plastic provide the wrong environment for neural cells, possibly altering cells’ responses to drugs as compared to how cells would respond in the body. Moreover, it is not possible to study myelination in these flat dishes, because this process requires the presence of three-dimensional, axon-like structures. The artificial axons, on the other hand, mimic real axons’ low mechanical stiffness, which is six orders of magnitude less stiff than plastic dishes, as well as axons’ geometrical properties, down to orders of micrometers. The artificial axons are also drug-agnostic, meaning they allow a variety of compounds to be tested on it. The platform is highly tunable. Artificial axons can be printed with different shapes, diameters, densities, mechanical properties, and surface ligands to model specific diseases.

Our format is compatible with pharmaceutical setups for drug screening. We have improved fabrication throughput to produce samples with high reproducibility in a short period of time, a 96-well plate within minutes.

Q: How is the composition of your team especially suited to creating these tools for the drug discovery process?

A: Our group in the Van Vliet Laboratory for Material Chemomechanics is diverse in expertise. We have people with experience in both cell biology and materials development. We also develop tools to study and characterize cells and their tissue environment, to understand how this environment drives cell behavior in health and disease. We worked for years to understand axon geometry and stiffness change in neurodegenerative diseases, and how this affects myelin repair. This knowledge of the interactions between neural cells and their environment allowed us to create artificial axons that mimic the key features of the brain environment that are important for biology of neural cells and myelination.

To mimic axons, we developed a novel biocompatible, ultraviolet-curable hydrogel. This material enabled the creation of very thin, freestanding fibers with extremely low stiffness, similar to real axons. To develop a reliable fabrication technology for our platform, graduate student Daniela Espinosa-Hoyos PhD ’20 and I then teamed up with the group of Professor Nicholas Fang in the Department of Mechanical Engineering, the experts in 3D printing. They built specialized 3D printers based on a technique called projection micro-stereolithography. Together, we developed a method that can reproducibly produce these complex micrometer-scale structures. This work built on an earlier collaboration with the group of Jennifer Lewis, a Harvard University professor, using direct inkjet printing of supported hydrogel fibers.

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Letter from President Reif: A new future for edX

To the members of the MIT community,

I write to share important news about the future of edX, the nonprofit that MIT and Harvard launched together in 2012 to offer the world an open-source online learning platform for university-level courses.

I will begin with the news and then offer some context and detail.

The news

After a thorough and thoughtful process, and with the support of the senior leadership of MIT and Harvard, the edX board has agreed to sell the assets of edX to 2U, Inc., a publicly traded company that provides a platform for lifelong learning.

Through this acquisition, edX will become a 2U subsidiary as a “public benefit company,” which will allow edX’s long-standing commitment to the public good to be embedded in its new charter. The overall agreement actively sustains the mission of edX through a series of provisions that protect learner data, ensure free and low-cost access to courses, preserve choice for partner universities and faculty, and continue the open-source platform Open edX.

The proceeds of the transaction – $800 million – will flow into a nonprofit entity with a refreshed educational mission and a new name. Governed by MIT and Harvard, this nonprofit will steward and enhance the Open edX platform and explore promising new ideas for making online learning more effective, engaging and personalized.

Why this move now?

In broad strokes, Covid drove an explosion in remote learning, which spurred huge investments into edX’s commercial competitors. This put edX, as a nonprofit, at a financial disadvantage. This new path recognizes this reality and offers a solution that allows edX to continue to support and maintain the key aspects of its mission.

I know this news is a surprise and will take some time to absorb. So I would like to provide some background and share the process behind this decision.

How edX began and grew

Nine years ago, when massive open online courses (MOOCs) were just becoming popular, we joined forces with Harvard to seize the opportunity to launch edX. Building on the spirit of MIT OpenCourseWare, we set out together to provide a clear public good: an open-source, nonprofit platform that we and other institutions could use to teach our own students and to provide free, interactive college-level course content for learners around the world.

Since then, with leadership from edX CEO and MIT professor Anant Agarwal and his team, edX has engaged 160 partner institutions, reached more than 39 million learners across nearly every nation, exceeded 110 million course enrollments and pioneered new online credentials including the MicroMasters.

Key aspects of edX’s founding vision have also become signature features of the educational landscape. By its very existence, edX established the expectation that online learning should include free access to rigorous college course content. edX also helped pioneer the idea of aggregating courses from many institutions.

All of us can take pride in what edX has accomplished, including – and perhaps most significant – edX’s role in helping create a thriving market for online learning.

A changing landscape

In recent years, as global demand for online learning rose sharply, the field was already drawing intense interest from investors. When Covid hit, and remote learning became the dominant avenue for delivering education everywhere, the commercial platform companies became magnets for outside investment on a startling scale.

This infusion of funds is fueling an arms race, in which competitors strive to out-do each other in improving their online platforms, in marketing to learners and in providing financial packages to recruit partner universities to supply course content.  

Observing this trend almost a year ago, the members of the edX board – including senior leaders from both MIT and Harvard – came to see that the scale of the dollars had radically tipped the playing field. As a nonprofit, edX could no longer keep up. So the board began a systematic review of alternative ways to try to sustain edX’s mission in the future.

In the midst of this review last fall, edX received a confidential inquiry from 2U, a well-established publicly traded platform company. (2U already works with MIT: The School of Architecture and Planning, the Sloan School of Management, the Media Lab and CSAIL all offer courses on 2U’s platform.) 2U was interested in a deal with edX.

A new pathway

The offer crystallized the board’s understanding that it was time to stop straining to keep up with supercharged commercial course-aggregation platforms and instead reembrace edX’s role as a channel for influential innovation in online learning.

Seeing the 2U proposal as a promising opening but not yet a finished solution, the board members shared their initial thinking with me and other senior leaders at MIT and Harvard.

I now understand that this path is very much in the best interests of MIT – but the idea took some getting used to. We had never set out to have edX become part of a commercial enterprise. We worked together with the board through a process of due diligence to assess alternatives, including philanthropy or a partnership.

A key concern was how to preserve the privacy of learner data. edX has long set a standard for protecting learner data; giving up those protections would be unacceptable. We knew it was also crucial to make sure faculty could choose the platform their courses would run on.

At the same time, the transformation of the landscape was undeniable. Finding a new path forward was a must – and focusing on educational innovation felt obviously right.

It took several months of reflection and negotiation to work through our questions and confirm that the board had indeed arrived at the best option. A great frustration through this period was that because 2U is a publicly traded company and therefore subject to securities regulations, we were legally prohibited from consulting our communities broadly. Given that, we were especially grateful to tap the wisdom of a small group of faculty leaders and experts on digital learning and data privacy.

Through this process, we were pleased to find a path agreeable to both founding universities, to edX and to 2U: a future for edX as a public benefit company that will pair the resources of a for-profit player with a formal mission to serve the public good.

Late last week, Provost Marty Schmidt and I met with a number of faculty leaders to share the high-level details and hear their thoughts.

Which brings us back to today’s announcement.

The transaction we announce today

Pending approval by the Office of the Massachusetts Attorney General and other government regulators, the transaction will have two major outcomes:

1. As a subsidiary of 2U, edX will become a “public benefit company.” The public benefit designation emerged about a decade ago as a way for a for-profit company to commit, in its charter, to focus on achieving one or more public benefits in addition to serving its shareholders. Familiar examples of public benefit corporations include Patagonia, Kickstarter, Ben and Jerry’s and, close to home, The Engine.

In this new incarnation, edX will operate under a set of guidelines that will preserve its mission to make rigorous university-level courses accessible and free for learners everywhere, and that also reflect MIT and Harvard’s standards and values around learner data.

Joining 2U will allow edX to offer learners a broad new array of benefits and services and to provide faculty members and universities with much greater reach and more options for how to share their classes, without restricting them to any one platform.
 
2. 2U will provide $800 million to fund a nonprofit governed by MIT and Harvard that will focus on reinventing digital learning. Except for funds edX will use to repay loans from MIT and Harvard, the proceeds from this transaction will flow directly to the nonprofit – not to Harvard and not to MIT.

Freed from competing in the course-aggregation race and equipped with these significant new resources, the nonprofit will have the power to do what edX could not: invest at the necessary scale to sustain Open edX as a fresh, vital, open-source learning platform for the world, and help tackle the next great research challenges in online learning.

It could, for example, invest in the potential of AI and other tools to make online learning more responsive and personalized to the individual learner; I believe this is a critical path to meet the needs of people that online learning often leaves behind, including students and workers of any age seeking the skills to keep pace with a shifting economy. We also expect the nonprofit to collaborate with and learn from organizations that have a direct, hands-on understanding of the learning needs of various communities.

The nonprofit’s detailed mission, name, research and activities will be developed following consultation with the faculty of both universities and edX partner institutions. I will work together with the chair of the faculty to develop a plan for engaging faculty on these important matters.

We also hope that it will be possible for faculty and other stakeholders to help shape the nonprofit’s agenda by applying to it for research grants. Its overall mandate, however, is already clear: to create a new public good commensurate with the legacy of edX.

As soon as we can, we will share more about how faculty will be engaged in contributing to the nonprofit’s focus and aspirations.

Learning more

Given the scale of these changes, I expect you will have many questions.

As a starting point, I urge you to read the complete story on MIT News, which summarizes the commitments at the heart of the arrangement that preserve the edX mission. There is also an FAQ that offers more detail.

As we begin this exciting new chapter, I would like to express my deep appreciation to edX CEO Anant Agarwal and the entire edX team for nearly a decade of creativity, perseverance and accomplishment against the odds, and to share my great admiration and gratitude for all the MIT faculty, instructors and staff who have built so many compelling courses on MITx.

I also want to recognize the exceptional efforts of everyone who helped define and improve this new path, including the MIT members of the edX board and their Harvard counterparts. Their thoughtful stewardship and creative thinking have been indispensable.

For me – and perhaps for many of you and our Harvard colleagues who envisioned, shaped and nurtured edX along with us – turning this corner is naturally bittersweet.

Yet at the same time, I am extraordinarily proud of edX and the impact it has had on learning, I am convinced that this decision represents the best path for MIT and I am extremely enthusiastic about what the future holds, for MIT, for online learning and for education as a whole.

With high hopes for how our community can continue to help advance the frontiers of online learning,

L. Rafael Reif

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LIGO and Virgo detect rare mergers of black holes with neutron stars for the first time

Today, an international team of scientists, including researchers at MIT, have announced the detection of a new kind of astrophysical system: a collision between a black hole and a neutron star — two of the densest, most exotic objects in the universe.

Scientists have detected signals of colliding black holes, and colliding neutron stars, but had not confirmed a merging of a black hole with a neutron star until now. In a study appearing today in The Astrophysical Journal Letters, the scientists report observing not just one, but two such rare events, each of which gave off gravitational waves that reverberated across a large swath of the universe before reaching Earth in January 2020, just 10 days apart.

The gravitational waves from both collisions were detected by the National Science Foundation’s Laser Interferometer Gravitational-Wave Observatory (LIGO) in the United States, and by Virgo in Italy. The events are named GW200105 and GW200115, for the date when each gravitational wave was observed. Both signals represent the final moments as a black hole and a neutron star spiraled in and merged together. For GW200105, the black hole is estimated to be about 9 times the mass of the sun, with a companion neutron star of about 1.9 solar masses. The the two objects are estimated to have merged around 900 million years ago. GW200115 is the product of a 6-solar-mass black hole, which collided with a neutron star about 1.5 times the mass of our sun, around 1 billion years ago. In both events, the black holes were large enough that they likely devoured their neutron stars completely, leaving very little to no light in their aftermath.

LIGO team member Salvatore Vitale, MIT assistant professor of physics, and a member of the Kavli Institute for Astrophysics and Space Research, spoke with MIT News about the rarity of both detections, and what the mergers of black holes and neutron stars may reveal about the evolution of stars in the universe.

Q: Tell us about these extreme, elusive systems. In general, what was known about collisions involving black holes and neutron stars prior to these detections?

A: Both neutron stars and black holes are left behind by massive stars once they run out of nuclear fuel. Since a large fraction of the stars in the universe are in binary systems, one would expect the existence of all possible pairwise combinations: two neutron stars, two black holes, or a neutron star and a black hole.

Neutron star binaries have been known for decades, discovered using electromagnetic radiation. Black hole binaries were observed for the first time in 2015, with the gravitational-wave detection GW150914. After that, gravitational-wave detectors such as LIGO and Virgo have discovered tens of binary black holes and two binary neutron stars. However, binaries with one neutron star and one black hole (NSBH) had never been found using electromagnetic radiation, nor with gravitational waves, at least until now.

Q: What can you tell from the signal about the possible scenarios that could have brought these objects together in the first place?

Sadly, not very much, at this stage! The most likely scenario is that the two objects in each binary have been together their whole life, as giant stars. As they ran out of fuel, they went through powerful explosions known as supernovae, leaving behind a neutron star and a black hole. The two objects in the binary then got closer and closer, since they lose energy through gravitational-wave emission, until they collide. LIGO and Virgo saw the last few seconds leading to the collision. 

Theoretically these mergers could produce light, which is extremely exciting! However, for that to happen, one needs some matter to be left around the system after the collision. Unfortunately, if the black hole is too massive, or if it doesn’t rotate fast enough around its axis, it will entirely swallow the neutron star before this has a chance to get torn apart. When this happens, no matter is left behind, and hence no light. This is what might have happened with both of these gravitational-wave detections.

However, it is also possible that light was, in fact, emitted but was not detected by the telescopes that followed-up these systems. This is because their position in the sky — based on the gravitational-wave data — was rather uncertain, which implies telescopes might not have had a chance to find the electromagnetic counterpart before it faded away.

Q: What is the overall significance of this new detection? And what avenues does this open up in our understanding of the universe? 

A: These two systems are important since they are the first clear discovery of neutron star black hole binaries, a type of source that had never been observed, with either electromagnetic or gravitational waves. It tells us that these systems do exist but are more rare than binary neutron stars. With only two sources, the numbers are still very uncertain, but roughly: for every 10 neutron star binaries, there is one NSBH merger. 

The merger rate that we have calculated using these two signals, and the properties of the compact objects, will be a tremendous help to astronomers and modelers trying to understand formation and the evolution of NSBHs.

In fact, since none had ever been observed before, there wasn’t a good way to refine theoretical and numerical models. Those models are complicated and depend on many of the physical parameters of the binary system, as well as its history. For example: How violent is the supernova explosion that leaves behind neutron stars and black holes? Is it so powerful that it can destroy the binary system altogether?

Finally having access to NSBH mergers will help refine these models, and hence our understanding of the formation and evolution of compact objects. 

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FAQs on agreement to sell edX to 2U, Inc. and fund nonprofit to reimagine digital learning

This set of FAQs offers information about today’s announcement of a transaction to sell edX as a public benefit company while funding a nonprofit dedicated to strengthening the impact of digital learning. 

General questions 

1. What is MIT announcing today? 

With the support of the senior leadership of MIT and Harvard University, the edX board has agreed to sell the assets of edX to 2U, Inc., a publicly traded company that provides a platform for life-long learning.

Through this acquisition, edX — the nonprofit MIT and Harvard launched together in 2012 to offer the world an open-source online learning platform for university-level courses — will become a 2U subsidiary as a “public benefit company,” which will allow edX’s long-standing commitment to the public good to be embedded in its new charter. The overall agreement actively sustains the mission of edX through a series of provisions that protect learner data, ensure free and low-cost access to courses, preserve choice for partner universities and faculty, and continue the open-source platform.

The proceeds of the transaction — $800 million — will flow into a remaining nonprofit entity with a refreshed educational mission and a new name. Governed by MIT and Harvard, this nonprofit will steward and enhance the Open edX platform and explore promising new ways to make online learning more effective, engaging, and personalized.

2. Is the transaction complete? 

No. The transaction is expected to close this fall, subject to customary closing conditions and certain regulatory and governmental approvals, including approval by the Office of the Massachusetts Attorney General.

3. What will happen to edX? 

If the transaction is approved as proposed, edX’s assets will be transferred to a public benefit company owned by 2U. As a subsidiary of 2U named edX, it will contain the current portfolio of edX course offerings, partner arrangements, and base of users. The public benefit designation emerged about a decade ago as a way for a for-profit company to commit, in its charter, to focus on achieving one or more public benefits in addition to serving its shareholders. Familiar examples of public benefit corporations include Patagonia, Kickstarter, Ben and Jerry’s, and The Engine. In this new incarnation, edX will operate under a set of guidelines that will preserve its mission.

4. What will happen to MITx? 

MITx — the Institute’s portfolio of massive open online courses (MOOCs) — will endure. Faculty will have several options for their MITx classes: continue to offer them on edX; move them to a new platform we are referring to as MITx Online; explore options like OpenCourseWare or the Open Learning Library; or remove them altogether. MIT Open Learning will work with faculty to help them understand their options in more detail.

5. What is MITx Online?

MIT Open Learning is building a new world-facing platform based on Open edX to serve as a platform for MITx MOOCs. We are referring to it as MITx Online. Unlike edX, MITx Online will not aggregate content generated by other institutions; it will serve as a home for MOOCs from MITx only.

The Transaction 

6. What prompted edX to do this now? 

Even before the pandemic, online learning was the subject of intense interest from investors. This past year, as remote learning became the dominant avenue for delivering education everywhere, commercial educational technology companies and platforms became magnets for outside investment. This infusion of funds gave them an advantage in improving their online platforms, marketing their content to learners, and signing up new partner universities.

Almost a year ago, recognizing this disruptive transformation of the market, the edX board, which includes representatives from both MIT and Harvard, began to explore alternatives for sustaining edX’s mission into the future. One of the options edX considered was a transaction with 2U, a publicly traded educational technology company with many partner institutions, including MIT and Harvard. Detailed discussions between the edX board and 2U began in earnest in February of this year.

7. Why not just let edX continue as long as possible in its current nonprofit form, with the hope that another solution will present itself?  

The edX board explored other options with the assistance of an outside investment advisor and nonprofit attorneys, and ultimately determined that those options were not as beneficial to edX, its learners, or its partner institutions as the transaction with 2U. The transaction with 2U allows edX, MIT, and Harvard to preserve much of the public good of edX and presents an opportunity to build on that success with a new initiative focused on shaping the future of digital learning. 

8. Is edX selling because a nonprofit model simply isn’t viable in the online learning space? 

As currently structured and funded, edX does not have the resources to compete in the rapidly evolving for-profit online learning marketplace as a platform that aggregates course content from other institutions. For several years, online learning has been the subject of growing investment by commercial firms. The pandemic accelerated that trend, with increasing investment enabling those companies to improve their online platforms and spend heavily on marketing to learners and universities.

9. Why wasn’t a transaction presented and discussed in an open setting? 

A standard condition of these types of transactions — involving a publicly traded company subject to securities regulations — is that the parties must maintain confidentiality while discussions are ongoing. Early in 2021, MIT leadership began consulting with the Executive Committee of the Corporation and then with MIT and Harvard faculty who have expertise in digital learning and data privacy. President L. Rafael Reif and Provost Martin Schmidt recently met with faculty leaders to brief them on the negotiations.

10. Will MIT profit from the transaction? 

No. Except for funds edX will use to repay a recent line of credit from MIT and Harvard, the full proceeds from the transaction will flow directly to the nonprofit the universities will govern together, and not to either university. Over the years, MIT and Harvard have contributed $80 million total ($40 million each) to edX; they will not recoup those funds from the sale.

Because edX is a public charity, the proceeds from its sale can only be distributed for a purpose consistent with edX’s mission, not to compensate those who contributed to the nonprofit. 

11. Did edX, MIT, and Harvard consider how this sale would affect low-income users? 

Yes. The transaction ensures that edX, as a public benefit corporation operated by 2U, will continue to offer free courses and certificates with modest fees — the current edX model. And the proceeds from the sale present an opportunity to reimagine the existing nonprofit to more effectively address inequities that exist in digital learning. 

12. How long has this been under consideration? 

Starting last fall, the edX board undertook an assessment of options to continue advancing the edX mission while also supporting its partners and learners. In the fall and winter, edX considered all options and entered into discussions with a number of potential partners. Discussions between 2U and the edX board began in earnest in February 2021. 

2U, Inc.

13. What is 2U? 

Launched in 2008, 2U is a publicly traded educational technology company that provides colleges and universities a cloud-based platform for their course offerings. It has more than 75 partners, including MIT and Harvard, and hosts and supports more than 500 digital educational offerings. 

14. Why 2U? 

2U’s mission defines it as “a diverse collection of more than 4,000 individuals who share a common belief in the power of education to transform lives for the better.” That mission resonates deeply with edX, as well as with MIT and Harvard. The provisions the edX board negotiated with 2U allow edX’s mission to be preserved. Among those provisions, which will remain in effect for five years, 2U will:

• guarantee affordability through the continuation of a free track to audit every course;
• protect the intellectual property rights of member partners that contribute massive open online courses;
• ensure that participating colleges and universities may continue under their standing agreements with edX;
• protect the privacy of individual data for all learners who use the edX platform;

• work toward launching affordable, stackable, modular bachelor’s degrees built from MicroBachelors programs;
• participate actively in improving the Open edX code to improve engagement, pedagogy, learning outcomes, and blended learning features;
• increase the number of courses available in non-English-speaking markets;
• continue to offer a broad range of courses, across disciplines;
• provide accessibility features for learners with disabilities;
• host all courses that a member institution chooses to put on the edX platform; and
• maintain quality for new courses across all member institutions.

2U has also agreed to limit its use of sensitive individualized information based on learner choice. Basic contact information would be available to 2U for learner communications, and learners will have the option to continue learning with edX or opt out and have all their information, including basic contact data, permanently deleted.

In addition, the proceeds of the transaction will allow the remaining nonprofit MIT and Harvard will govern to pursue new opportunities in digital learning, with a focus on promoting a more personalized learning experience and a commitment to creating learning opportunities for those from disadvantaged backgrounds. 

Nonprofit entity 

15. What is the nonprofit that MIT and Harvard will govern once the transaction is complete? 

The proceeds of the transaction — approximately $800 million — will flow into a remaining nonprofit entity with an updated educational mission and a new name. Governed by MIT and Harvard, this nonprofit will steward and enhance the Open edX platform and explore new ways to make online learning more effective, engaging, and personalized.

The nonprofit will aim to do what edX could not: invest at the necessary scale to sustain Open edX as a fresh, vital, open-source learning platform for the world, and tackle the next great research challenges in online learning. It could, for example, invest in the potential of artificial intelligence to make online learning more responsive and personalized to the individual learner.

The nonprofit’s detailed mission, name, and research program will be developed following consultation with the faculty of both MIT and Harvard, as well as with edX partner institutions. The input of faculty and other stakeholders will help the board of the new nonprofit shape its agenda. Further, the edX partners may be able to engage with the new nonprofit in the future through grant making and partnerships. President Reif will work with the chair of the faculty to develop a plan for engaging MIT faculty in contributing to the new nonprofit’s focus and aspirations. 

edX 

16. What is edX? 

In 2012, building on the success of MIT OpenCourseWare, MIT and Harvard jointly launched edX, an open-source technology platform for online courses. edX is an independent 501(c)(3) with a board of leaders who have a fiduciary responsibility to edX. 

Universities, including MIT, via MITx, work with faculty to develop courses for the edX platform. Over the last nine years, edX has reached more than 39 million learners and engaged more than 160 partner institutions. Its mission calls on it to increase access to high-quality education for everyone, everywhere; enhance teaching and learning on campus and online; and advance teaching and learning through research. 

17. Will MIT have any involvement with edX after the deal closes? 

MIT expects to continue to offer MITx courses both on edX as a public benefit subsidiary of 2U and on MITx Online, a new world-facing platform based on Open edX that MIT is creating for MITx MOOCs. MIT will not have an oversight or governance role with edX once the transaction is complete. However, the newly named nonprofit will remain engaged with edX in ensuring it follows the guiding mission and privacy commitments that have been agreed to.

18. What does this mean for edX employees? 

2U plans to retain all current edX employees who do not remain with the nonprofit continuing under Harvard and MIT’s leadership. Staff will remain in their current roles and teams for the immediate future as 2U determines the ideal timeline and plan for bringing the two organizations together.

19. What does this mean for edX CEO Anant Agarwal?

Anant Agarwal will continue to lead edX as the Massachusetts Attorney General’s Office conducts its review of the transaction. Professor Agarwal remains a tenured member of the MIT faculty and a leader in his field. In the months ahead, he will have many options and opportunities to consider, including potentially with the public benefit company edX or the nonprofit MIT and Harvard will govern.

Impact for edX stakeholders 

20. What will change and what will stay the same? 

The experience for edX learners should remain largely unchanged. They will retain access to their credentials, a free audit track, and a commitment to data privacy. Faculty will have several options for their MITx classes: continue to offer them on edX; move them to a new platform we are referring to as MITx Online; explore options like OpenCourseWare or the Open Learning Library; or remove them altogether. MIT Open Learning will work with faculty to help them understand their options in more detail.

21. What does this mean for MIT faculty whose classes are on edX? 

Faculty will retain all existing intellectual property agreements for all of their course content. Those who choose to continue to offer their courses on edX after the transaction closes will be able to decide what courses to offer and when, and will continue to control all decisions around course design. Those who choose not to offer their courses on edX will be able to move them to MITx Online — a new world-facing platform MIT is creating for MITx MOOCs — explore options like OpenCourseWare or the Open Learning Library; or request removal for any or no reason. All pricing decisions for MITx courses on the edX platform will continue to be made by MIT.

22. What does this mean for MITx learners? 

The user experience will be very similar, and learners will retain access to their credentials, a free audit track, and a commitment to data privacy.

23. Will learners have to pay to take courses with 2U after the transaction? 

edX as a public benefit company will continue to offer free courses for at least five years. 2U, which will own and operate edX, has also committed to continue to make available courses for which full participation is available at low cost, and make available a free audit track for every course. Individual faculty who wish to continue to offer a free audit track for their courses on edX will have the option to do so. Finally, any pricing decisions will continue to be made together with the institution where a course originated.

24. Does MIT still plan to use the Open edX platform? 

Yes. The nonprofit MIT and Harvard will govern together will continue to own and advance Open edX. In fact, Open edX will serve as the basis for a new world-facing platform we are referring to as MITx Online, for MITx MOOCs.

25. What does this mean for partner edX institutions? 

Under the terms of the transaction, partner edX universities will have the option of continuing to offer their courses under the same terms as their current agreements.

Data Privacy 

26. What steps have been taken to protect the data of edX users? 

Protections for learner data were central to the negotiation. 2U has agreed to data protections for everyone who has used edX to date as well as data-usage standards that will protect new edX users. 2U will not use the individual data edX has accumulated on courses taken, grades earned, and other sensitive individualized information, unless learners opt in to sharing that personal data. Learners can opt out at any time.

27. What data will 2U receive as part of the transfer of edX? 

Basic contact information for learners, such as their names and emails as well as information about courses taken — though not about performance — will be available to 2U as part of the transfer of edX assets. Even then, learners will be offered the option to opt out and have all of their information permanently deleted.

de MIT News https://ift.tt/3jpw2Gb

MIT and Harvard agree to transfer edX to ed-tech firm 2U

MIT and Harvard University have announced a major transition for edX, the nonprofit organization they launched in 2012 to provide an open online platform for university courses: edX’s assets are to be acquired by the publicly-traded education technology company 2U, and reorganized as a public benefit company under the 2U umbrella.  

The transaction is structured to ensure that edX continues in its founding mission, and features a wide array of protections for edX learners, partners, and faculty who contribute courses.

In exchange, 2U will transfer $800 million to a nonprofit organization, also led by MIT and Harvard, to explore the next generation of online education. Backed by these substantial resources, the nonprofit will focus on overcoming persistent inequities in online learning, in part through exploring how to apply artificial intelligence to enable personalized learning that responds and adapts to the style and needs of the individual learner.

The nonprofit venture will be overseen by a board appointed by MIT and Harvard, and its future work will draw on ideas from current edX partners, as well as MIT and Harvard faculty.

Celebrating the past, building a new future

In a letter to the MIT community sharing the news, President L. Rafael Reif noted that edX has engaged 160 partner institutions, reached more than 39 million learners, and exceeded 110 million course enrollments. “All of us can take pride in what edX has accomplished, including — and perhaps most significant — edX’s role in helping create a thriving market for online learning,” he wrote.

The transaction announced today was spurred by rapid and profound shifts in that online-learning market over the past 18 months. With the onset of the global pandemic and the accompanying surge in remote learning, publicly-traded ed-tech firms have attracted major investment, making it increasingly challenging for a nonprofit to keep pace.

Almost a year ago, recognizing this disruptive transformation of the market, the edX board began to explore what it would take to sustain edX’s mission in the future.

Reif acknowledged in his letter that the initial expression of interest from 2U “took some getting used to.” But following several months of reflection, debate, and negotiation, he said the parties found an agreeable path: “a future for edX as a public benefit company that will pair the resources of a for-profit player with a formal mission to serve the public good.”

Encoded into law in most states, benefit companies emerged about a decade ago as a legally protected way for companies to commit to the public good. The designation allows a commercial venture to seek to make positive impacts for societal stakeholders while also serving company shareholders. Familiar examples of benefit companies include Patagonia, Kickstarter, and Ben and Jerry’s. MIT’s own innovation fund, The Engine, is also a benefit company.

The future of Open edX

If the deal is approved by state regulators, 2U will pay $800 million for the right to adopt edX as a subsidiary and take on the current portfolio of edX course offerings, partner arrangements, and base of users.

However, the Open edX open-source software platform, upon which edX and more than 2,000 other learning sites around the world are based, would not be transferred to 2U. The nonprofit would own and enhance Open edX, ensuring its continued wide availability — including its ongoing use by edX.

MIT will continue to offer courses to learners worldwide via edX, as well as on a new platform now known as MITx Online. MIT’s Office of Digital Learning will build and operate MITx Online as a new world-facing platform, based on Open edX, that MIT is creating for MITx MOOCs.

MIT faculty may choose to continue to offer their courses through the new edX after the transaction is completed, or move them to MITx Online.

Under the terms of the transaction, partner edX universities would have the option of continuing to offer their courses under the same terms as their current agreements. The transaction imposes no restrictions on these institutions’ freedom to offer their courses through other means, or to depart edX.

Other protections for learners, partners, and staff

In an array of provisions within the negotiated agreement, 2U has embraced edX’s mission and agreed to data protections for everyone who has used edX to date — more than 39 million learners — as well as data-usage standards that would protect new edX users.

As part of these provisions, 2U has agreed to limit its use of sensitive individualized information based on learner choice. Basic contact information would be available to 2U for learner communications, and learners will have the option to continue learning with edX or opt out and have all their information, including basic contact data, permanently deleted.

Among other agreements as part of the deal, 2U has also committed to:

• guarantee affordability through the continuation of a free track to audit every course;
• protect the intellectual property rights of member partners that contribute MOOCs;
• ensure that participating colleges and universities may continue under their standing agreements with edX;
• protect the privacy of individual data for all learners who use the edX platform;
• work toward launching affordable, stackable, modular bachelor’s degrees built from MicroBachelors programs;
• participate actively in improving the Open edX code to improve engagement, pedagogy, learning outcomes, and blended learning features;
• increase the number of courses available in non-English-speaking markets;
• continue to offer a broad range of courses, across disciplines;
• provide accessibility features for learners with disabilities; and
• host all courses that a member institution chooses to put on the edX platform.

Finally, 2U plans to retain all current edX employees who do not remain with the nonprofit continuing under Harvard and MIT’s leadership. Staff will remain in their current roles and teams for the immediate future as 2U determines the ideal timeline and plan for bringing the two organizations together.

The transaction was approved by the edX board, as well as governance bodies at MIT and Harvard. It is expected to close this fall, subject to customary closing conditions and certain regulatory and governmental approvals, including approval by the Office of the Massachusetts Attorney General.

The launch of a refreshed mission to reimagine learning

As was the case with edX, the resulting nonprofit will continue to be a free-standing organization with a board appointed by MIT and Harvard. However, it will have significantly more funding, and its mission will differ: While edX will continue under 2U as an aggregator of university-level courses, the nonprofit will instead focus on the development of more personalized and responsive learning experiences that can be applied across the educational spectrum — from high school, to community college, to adults trying to create opportunity for themselves in a changing economy.

The nonprofit will invest in research, fund pilots, and promote the adoption of insights across the education spectrum. It will also seek out collaborations and aim to fund local partners to more effectively serve students from disadvantaged backgrounds, as well as identify how to most effectively blend digital tools with in-person support to help students learn — particularly those for whom online learning has been more a promise than a reality.

The continuation of a vision

Over its nine years, edX has achieved remarkable success in advancing its vision of making high-quality university courses available to people everywhere. With some 3,000 courses offered, and more than 1.4 million certificates issued to learners, edX has helped build a booming marketplace for college-level content. It has also pioneered formal university credit for some of its offerings, including innovations such as the MicroMasters and MicroBachelors credential programs.

“The willingness of 2U to help us create a unique deal presents exciting possibilities,” says Sanjay Sarma, MIT’s vice president for open learning and the Fred Fort Flowers and Daniel Fort Flowers Professor of Mechanical Engineering. “It gives us a chance to do something we had aimed to do from the start — create breakthroughs that advance how teaching and learning take place.”

“To be honest, as good as online education has become, it’s still not easy to sit in your kitchen or bedroom and take a college class,” Reif adds. “With this move, the educational nonprofit will develop new tools and techniques to make learning more personal, more meaningful, and easier for people all over the world at any stage in their lives, careers or preparation. That was the road we set out on with edX, and this represents the next stage in that journey.”

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