Two Caltech Alumni Receive Breakthrough Prize

Two Caltech alumni, Arthur McDonald (PhD '70) and Ian Agol (BS '92), have been named recipients of 2016 Breakthrough Prize awards. The prizes, which each carry a monetary award of $3 million, are given annually for achievements in mathematics and science to "encourage more pioneering research and celebrate scientists as the heroes they truly are," says Mark Zuckerberg, one of the prizes' founders.

The 2016 Breakthrough Prize in Fundamental Physics was awarded collectively to a community of more than 1,300 physicists who participated in five experiments investigating neutrinos, one of the most abundant particles in the known universe. McDonald—a 2015 Nobel laureate—was one of the seven scientists who led these experiments, heading the Sudbury Neutrino Observatory collaboration in Ontario. Neutrinos are unaffected by the two strong fundamental forces of nature—electromagnetism and the strong nuclear force—and are thus elusive, traveling through the universe essentially unimpeded and near the speed of light.

McDonald is currently Professor Emeritus at Queen's University and earlier this year shared the Nobel Prize in Physics for "the discovery of neutrino oscillations, which shows that neutrinos have mass."

Ian Agol received the 2016 Breakthrough Prize in Mathematics for his "spectacular contributions to low-dimensional topology and geometric group theory, including work on the solutions of the tameness, virtual Haken and virtual fibering conjectures." Low-dimensional topology is a field that focuses on manifolds—objects that seem flat when observed at a small scale—in four or fewer dimensions. Earth is one example of a manifold—while it is actually spherical, we humans are too small to be able to perceive Earth's curvature, and thus Earth appears flat to us.

Agol is a professor of mathematics at UC Berkeley and is currently a visiting researcher at the Institute for Advanced Study in Princeton, New Jersey.

The Breakthrough Prize was founded by Sergey Brin of Google, and Anne Wojcicki of 23andMe; Jack Ma of Alibaba, and Cathy Zhang; Yuri Milner, a venture capitalist and physicist, and Julia Milner; and Mark Zuckerberg of Facebook, and Priscilla Chan. The awards were presented at a ceremony in San Francisco on November 8.

Previous Caltech winners include Alexei Kitaev, the Ronald and Maxine Linde Professor of Theoretical Physics and Mathematics, and John H. Schwarz, the Harold Brown Professor of Theoretical Physics, Emeritus, who won the Fundamental Physics prize in 2012 and 2014 respectively. Alexander Varshavsky, the Howard and Gwen Laurie Smits Professor of Cell Biology, received the Breakthrough Prize in Life Sciences in 2014.

Written by Lori Dajose

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Simon Receives Lifetime Achievement Award

Barry M. Simon, the International Business Machines (IBM) Professor of Mathematics and Theoretical Physics at Caltech, has been awarded the 2016 Leroy Steele Prize for Lifetime Achievement of the American Mathematical Society (AMS) for his "tremendous impact on the education and research of a whole generation of mathematical scientists through his significant research achievements, highly influential books, and mentoring of graduate students and postdocs," according to the prize citation.

In conferring the award, the AMS noted Simon's "career of exceptional achievement," which includes the publication of 333 papers and 16 books. Simon was specifically recognized for proving a number of fundamental results in statistical mechanics and for contributing to the construction of quantum fields in two space‐time dimensions—topics that, the AMS notes, have "grown into major industries"—as well as for his "definitive results" on the general theory of Schrödinger operators, work that is crucial to an understanding of quantum mechanics and that has led to diverse applications, from probability theory to theoretical physics. He has also made fundamental contributions to the theory of orthogonal polynomials and their asymptotics.

"Barry Simon is a powerhouse in mathematical physics and has had an outstanding career which this award attests to," says Vladimir Markovic, the John D. MacArthur Professor of Mathematics. "Caltech is lucky to have him."

"Barry is a driving force in mathematics at Caltech and has had enormous influence as a scholar, a teacher, and a mentor," says Fiona Harrison, the Benjamin M. Rosen Professor of Physics and holder of the Kent and Joyce Kresa Leadership Chair for the Division of Physics, Mathematics and Astronomy.

Simon spoke at the International Congress of Mathematics in 1974 and has since given almost every prestigious lecture available in mathematics and physics. He was named a fellow of the American Academy of Arts and Sciences in 2005, and was among the inaugural class of AMS fellows in 2012. In 2015, Simon was awarded the International János Bolyai Prize of Mathematics by the Hungarian Academy of Sciences, given every five years to honor internationally outstanding works in mathematics, and in 2012, he was given the Henri Poincaré Prize by the International Association of Mathematical Physics. The prize is awarded every three years in recognition of outstanding contributions in mathematical physics and accomplishments leading to novel developments in the field.

Simon received his AB from Harvard College in 1966 and his doctorate in physics from Princeton University in 1970. He held a joint appointment in the mathematics and physics departments at Princeton for the next decade. He first arrived at Caltech as a Sherman Fairchild Distinguished Visiting Scholar in 1980 and joined the faculty permanently in 1981. He became the IBM Professor in 1984.

Written by Kathy Svitil

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Veterans Day 2015, Caltech

On Wednesday, November 11, in commemoration of Veterans Day, Caltech honored its veterans with a breakfast and panel discussion held at the Athenaeum. "I'm so happy that Caltech is recognizing veterans," said Ciro Diaz, associate director of IT support services in IMSS.

The event commenced with the National Anthem sung by the Caltech chorale members in the presence of cadets from Blair High School's Junior ROTC program and color guard. After a breakfast during which President Rosenbaum welcomed the veterans, Ken Hargreaves, assistant vice president for strategy implementation and a veteran himself, moderated a panel discussion in which four other veterans—Mike Miranda, BBE division administrator; Kathy Carpenter, security technical operations manager; Larry D. James, deputy director of JPL; and Jon Paparsenos, executive director of development, academic divisions and regions—shared stories of how their experience in the military has molded their lives and careers.

"I want to personally thank the president for having this," said Shane Egan, an electrician from Caltech's electrical shop. "This is the first time I've had an employer officially host an event for us."



Credit: Jon Nalick/Caltech
A color guard of students from Blair High School's Junior ROTC program enter the Athenaeum at the start of the Veterans Day event.

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Where the orthodox and unorthodox meet ( Poet and musician Alicia Jo Rabins to read and perform at Harvard Hillel)

By Sarah Sweeney, Harvard Staff Writer

Alicia Jo Rabins stood looking at the girls in long skirts waiting outside the locked doors of her Barnard College dorm and wondered what was going on. It was a Saturday, Shabbat, and though Rabins was technically Jewish, she had been raised in a secular household in a Baltimore suburb, mostly clueless about her religious heritage.

“Finally, I asked one of the girls, and she said, ‘Oh, we don’t use electricity on Shabbat, so we’re waiting for someone to come through the doors first,’” since they were powered, remembered Rabins, a poet and musician who will speak and perform Monday at Harvard Hillel.

That dorm moment was one in a series of accidental exposures to orthodoxy. “It seemed so exotic, actually,” she said, “the idea that a rule from a spiritual tradition would be so detailed as to cause such a specific behavior. I was drawn to the idea of religious law as a sort of mindfulness practice.”

Rabins had always been fascinated by “the sacred,” a filmy and roving sense of holiness that she had pinned down in nature, and in brushes with Catholicism and James Joyce. “I had a pan-spiritual interest,” she said.

But still curious about those girls in long skirts, Rabins homed in on Judaism, showing up late for a Wednesday-night Torah study at Columbia University, where she was paired with an ultra-Orthodox girl of the same age.

“We would have these amazing conversations. I would be like ‘Do animals have souls?’ … these elementary-school questions, and she would be like, ‘Do you just have sex on a first date if you’re not religious?’ We had no idea about each other’s worlds, and it was an amazing way to encounter Jewish texts with someone who was also making this journey, but in a different direction.”

Rabins was well-versed in different directions. At age 3, her mother enrolled her in Suzuki method violin lessons, which Rabins loved though she eventually drifted away from the classical world to punk rock and folk music.

Exploring Judaism and differences further, after Barnard she enrolled in New York’s Jewish Theological Seminary, where for her thesis she composed a song cycle with lyrics about the lives of Biblical women. This sparked the formation of her current band, Girls in Trouble.

Along with music, there had always been poetry. Rabins earned an M.F.A. from Warren Wilson College, and her manuscript “Divinity School” was chosen by the poet C.D. Wright for the 2015 APR/Honickman First Book Prize.

The quotidian and the spiritual collide in Rabins’ work. A brief poem titled “How to Confess an Affair” reads like a cheeky extended haiku:

Details are fishhooks that will remain in the lip of the small fish
that lives inside your spouse and swims sometimes towards
you, sometimes away from you. If you love the fish, be careful.

In “Birth,” Rabins’ speaker is in labor:

Then the demons found me,
And one by one,
they placed their hands on my belly
and began to chant.

The newborn is a gift, but also a kind of terror: “And so it was that you were born, / little monster with my face.”

Now married and a mother of two, Rabins said that motherhood has broken her open: “It shows me strengths I didn’t know I had, weaknesses I didn’t know I had … it’s both revealing and psychedelic how far you can travel during one hour in a room with a 3-year-old.”

Rabins resides now in Portland, Ore., working as a Jewish educator, integrating art to help her students connect to Jewish texts. Along with Girls in Trouble, she occasionally tours with her one-woman chamber rock opera, “A Kaddish for Bernie Madoff,” and is hard at work on a second collection of poems.

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What’s past is prologue ( During Harvard appearance, Coates probes ongoing problems in criminal justice system)

By Christina Pazzanese, Harvard Staff Writer

Ongoing racial discrimination and institutional failures to dampen such abuses are roiling many college campuses, amid the larger national conversation spurred by the Black Lives Matter movement. In the swirl, few writers have so artfully articulated their era as the influential, best-selling author Ta-Nehisi Coates.

The national correspondent for The Atlantic and a 2015 MacArthur Foundation fellowship recipient, Coates’ article “The Case for Reparations” and his new book, “Between the World and Me,” are deeply powerful exhortations on the present-day manifestations of the nation’s fraught racial history.

Appearing before an electrified crowd at Harvard Kennedy School (HKS) Wednesday evening for a discussion about race and criminality, Coates was joined by moderator Bruce Western, director of the Malcolm Wiener Center for Social Policy at HKS; sociologist William Julius Wilson, the Lewis P. and Linda L. Geyser University Professor at Harvard; and Kathryn Edin, a former professor at HKS and now Distinguished Bloomberg Professor of Sociology and Public Health at Johns Hopkins University.

Coates argued that America’s practice of disproportionately criminalizing and incarcerating African-American men is a direct extension of our history of using the criminal justice system to address social problems, and of whites sometimes labeling black people as criminals in order to justify limiting their rights and “plundering” their labor.

“I believe that as much as George Washington matters, as much as the American Revolution matters, the heritage of telling ourselves certain things about black people also matters,” said Coates.

The country has a long history of defining black people, especially those who sought freedom, as criminals. For a century after Emancipation, white Americans mounted a “terrorist campaign” against blacks through lynching and other violence that was somehow justified by this “notion of criminality,” he said.

“It was common when African-Americans made demands for political rights to point to criminality as a response,” he said, noting that in their day, Frederick Douglass, Harriet Tubman, and even Martin Luther King Jr. often were seen not as heroes, but as troublemakers. King “was treated by the highest powers in this country like a criminal, and I think that heritage has some sort of effect” on why the rate of incarceration of black men is so high today, Coates said.

It’s not enough simply to free large numbers of non-violent prisoners in order to roll back the nation’s incarceration rate to the levels of the 1970s, as the Obama administration announced earlier this year it intends to do, said Coates. There needs to be a coherent plan to assist with their transition.

“So reparations, to me, is to push the idea that it’s not enough to just stop wounding someone; you actually have to heal someone. You actually have to do something about the harm that you produced. It’s not enough to simply say, ‘I’ve stopped harming,’” he said.

Changing the dynamics between blacks and whites will demand that people revise their self-definition. “I think it requires a critical mass of people in this country to give up a real interest” in their identity and standing in relation to one another, said Coates.

Coates said he’s been “shocked” at the reception to his book, which has been critically acclaimed and named a National Book Award finalist. The book recalls his upbringing in West Baltimore, where violence or the threat of violence was a constant fact of life, and appearing tough or “hard” was a logical response.

“One of the arguments I made in ‘Between the World and Me’ is that much of what people look at in black America and construe as anger is, in fact, deep, deep fear,” he said.

As a writer, Coates said he feels he has an obligation not to argue for what could realistically happen in the near future, but for what needs to happen over the long term, and hope that it moves the needle more substantively.

Asked to weigh in on the Yale University protest over racial discrimination and free speech, Coates said he didn’t feel sufficiently informed to render an opinion. But he characterized a debate there over offensive Halloween costumes and emails as undoubtedly a symptom of far deeper issues.

“I think, in these cases, we’re like five questions too late,” he said. “By the time that has become important, something else has really, really gone wrong.”

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New exoplanet in our neighborhood

Though likely uninhabitable, planet is rocky, Earth-sized, and near enough for study of its atmosphere.

Jennifer Chu | MIT News Office
November 11, 2015

Scientists have discovered a new exoplanet that, in the language of “Star Wars,” would be the polar opposite of frigid Hoth, and even more inhospitable than the deserts of Tatooine. But instead of residing in a galaxy far, far away, this new world is, galactically speaking, practically next door.

The new planet, named GJ 1132b, is Earth-sized and rocky, orbiting a small star located a mere 39 light-years from Earth, making it the closest Earth-sized exoplanet yet discovered. Astrophysicists from MIT and elsewhere have published these findings today in the journal Nature.

Based on their measurements, the scientists have determined that the planet is a roasting 500 degrees Fahrenheit, and is likely tidally locked, meaning that it has a permanent day and night side, presenting the same face to its star, much like our moon is locked to the Earth.

Because of its scorching temperatures, GJ 1132b most likely cannot retain liquid water on its surface, making it uninhabitable for life as we know it. However, scientists say it is cool enough to host a substantial atmosphere.

The planet is also close enough to Earth that scientists may soon be able to find out much more about its characteristics, from the composition of its atmosphere to the pattern of its winds — and even the color of its sunsets.

“If we find this pretty hot planet has managed to hang onto its atmosphere over the billions of years it’s been around, that bodes well for the long-term goal of studying cooler planets that could have life,” says Zachory Berta-Thompson, a postdoc in MIT’s Kavli Institute for Astrophysics and Space Research. “We finally have a target to point our telescopes at, and [can] dig much deeper into the workings of a rocky exoplanet, and what makes it tick.”

A nearby solar neighbor

Berta-Thompson and his colleagues discovered the planet using the MEarth-South Observatory, a Harvard University-led array of eight 40-centimeter-wide robotic telescopes located in the mountains of Chile. The array monitors small, nearby stars called M dwarfs, which are scattered all over the night sky. Scientists have determined that these kinds of stars are frequently orbited by planets, but haven’t yet found Earth-sized exoplanets that are close enough to study in depth.

Since early 2014, the telescope array has been gathering data almost every night, taking measurements of starlight every 25 minutes in search of telltale dips in brightness that may indicate a planet passing in front of a star.

On May 10, one telescope picked up a faint dip from GJ 1132, a star located 12 parsecs, or 39 light-years, from Earth.

“Our galaxy spans about 100,000 light-years,” Berta-Thompson says. “So this is definitely a very nearby solar neighborhood star.”
The robotic telescope immediately started observing GJ1132 at much faster 45-second intervals to confirm the measurement — a very slight dip of about 0.3 percent of the starlight. The researchers later pointed other telescopes in Chile at the star, and found that indeed, GJ 1132’s brightness dimmed by 0.3 percent every 1.6 days — a signal that a planet was regularly passing in front of the star.

“We didn’t know the planet’s period from one single event, but when we phased many of them together, this signal popped out,” Berta-Thompson says.
“Burnt-cookie hot”

Based on the amount of starlight the planet blocks, and the radius of the star, scientists calculated that planet GJ 1132b is about 1.2 times the size of Earth. From measuring the wobble of its host star, they estimate the planet’s mass to be about 1.6 times that of Earth. Given its size and mass, they could determine its density — and they believe it to be rocky, like Earth. However, size and composition are where the comparisons to our planet end.

By calculating the size of and proximity to its star, the group came up with an estimate of the planet’s average temperature: a scorching 500 kelvins, or 440 F.
“The temperature of the planet is about as hot as your oven will go, so it’s like burnt-cookie hot,” Berta-Thompson says. “It’s too hot to be habitable — there’s no way there’s liquid water on the surface. But it is a lot cooler than the other rocky planets that we know of.”
That’s good in terms of scientific study: Most rocky exoplanets that have been discovered so far are essentially fireballs, with surface temperatures in the thousands of degrees — far too hot to hold onto any kind of atmosphere.

“This planet is cool enough that it can retain an atmosphere,” Berta-Thompson says. “So we think this planet probably still has something of a substantial atmosphere, in its current state.”
Berta-Thompson hopes that astronomers will use the James Webb Space Telescope (JWST), the much larger successor to the Hubble Space Telescope that is launching in 2018, to identify the color and the chemical makeup of the planet’s atmosphere, along with the pattern of its winds.
“We think it’s the first opportunity we have to point our telescopes at a rocky exoplanet and get that kind of detail, to be able to measure the color of its sunset, or the speed of its winds, and really learn how rocky planets work out there in the universe,” Berta-Thompson says. “Those will be exciting observations to make.”

The MIT-led NASA Transiting Exoplanet Survey Satellite (TESS) will search the entire sky for nearby planets, and may find many more that would serve as good targets for JWST.
“Of the billions of star systems in the Milky Way galaxy, about 500 are closer than GJ1132,” Berta-Thompson says. “TESS will find planets around some of these stars, and those planets will be valuable comparisons for understanding GJ1132b and rocky planets in general.”

Jonathan Fortney, a professor of astronomy and physics at the University of California at Santa Cruz, says the new planet is a good deal cooler than other nearby rocky planets that have been discovered so far. This means that GJ1132b likely has a substantial atmosphere.


“What is tremendously exciting to me is that this planet could be a real ‘cousin’ of Venus and Earth,” says Fortney, who was not involved in the research. “I think that this planet’s atmosphere, when we are able to try to determine what it is made of, will be an interesting data point in understanding the diversity in atmospheric composition for Earth-sized planets. In our solar system, we only have two data points: Earth and Venus. Before we can understand habitability, I think we need to understand the range of atmospheres that nature makes, and why.”

This research was supported, in part, by the MIT Torres Fellowship for Exoplanet Research, the Harvard-Smithsonian Center for Astrophysics, the National Science Foundation, the David and Lucile Packard Foundation, and the John Templeton Foundation.

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DOE’s Kenderdine outlines nation’s energy priorities

Former executive director of MIT Energy Initiative describes roadmap for averting devastating climate change.
David L. Chandler | MIT News Office
November 10, 2015

Melanie Kenderdine, as the first executive director of the MIT Energy Initiative (MITEI), helped to launch an international program to increase women’s participation and leadership in the energy field called Clean Energy Education and Empowerment, or C3E, in 2012.

Last Thursday, Kenderdine, now the director of the Office of Energy Policy and Systems Analysis at the U.S. Department of Energy, returned to MIT to give the keynote address at the fourth annual U.S. C3E Women in Clean Energy symposium and awards program. Creating this event to recognize women in a variety of energy disciplines at all stages of their careers, she said, “was one of the most rewarding experiences I’ve ever had.”

In her talk at the two-day MITEI event, Kenderdine focused on the DOE’s recently released Quadrennial Energy Review, a project initiated by Secretary of Energy Ernest Moniz, MITEI’s former director, to outline priorities for the nation’s energy research and policies over the coming years. The report, she said, gives a sense of the “key drivers and challenges” in the field of energy.
Kenderdine began by recapping the scientific understanding of the threat of climate change, using a depiction of the probabilities of various outcomes developed by Ronald Prinn, co-director of MIT’s Joint Program on the Science and Policy of Global Change.

Prinn used a pair of roulette wheels to starkly communicate the dangers of inaction: The wheel reflecting the probabilities under a “business as usual” scenario shows a significant probability of an average temperature increase of 7 degrees Celsius by the century’s end — an outcome that Kenderdine deadpanned would be “shall we say, transformational for the planet.” (Most scientists agree that any increase of more than 2 C could produce catastrophic results.)
But that outcome is far from predetermined, she emphasized. In the corresponding roulette wheel, assuming that the world’s nations agree to substantial curbs in greenhouse gas emissions, the probability of exceeding that limit drops substantially. And there are indeed many options available to make such reductions practical, Kenderdine said.

Showing a chart of the sources and uses of the world’s various kinds of energy, Kenderdine pointed out that almost half of the world’s energy is wasted. Curbing even a fraction of that waste could make substantial dents in emissions.

That’s only one piece of the puzzle, since with growing population and rising standards of living, the world will consume a projected four times as much energy by 2100 as is used today, Kenderdine said. But there are some encouraging signs already.

Greenhouse gas emissions have actually been declining slightly, for example, even as world GDP has increased — providing a stark refutation of claims that the two measures change in lockstep. This is partly due to a dramatic shift from coal to natural gas, she said — a change largely enabled by DOE-funded innovations: “The DOE invested heavily in shale gas technology,” Kenderdine said.

But because energy industries are capital-intensive, with expensive plants built to operate for many decades, it is essential to have clear priorities for future development, so as to avoid huge investments in plants whose energy may grow incompatible with future economic and regulatory conditions.
One key need, Kenderdine said, to enable the new energy developments that are most needed, is a drastic modernization of the electric grid, which has grown up piecemeal over the last century. Another priority is to enhance the resiliency and reliability of the nation’s existing energy systems, she said.

For example, Kenderdine pointed out, 10 percent of the nation’s oil supply — the Strategic Petroleum Reserve — is held in tanks at a single location in Cushing, Oklahoma — right in the middle of “Tornado Alley.” And over 50 percent of the nation’s refining capacity is along the Gulf Coast, an area susceptible to intense hurricanes.

Some needed changes are in the regulatory domain, Kenderdine said. For example, current federal laws on replacing energy infrastructure after a natural disaster require replacing a facility as it was before the disaster, rather than allowing for modernization or improvement.

Another area where modernization is desperately needed, she said, is in natural gas delivery: Many gas lines in cities are decades old. Recent explosions in major cities have shown the dangers of leaking gas pipes, and the need for replacing those old pipes: An explosion that leveled an apartment complex in New York last year, for example, involved a pipe system that was 104 years old. Boston, Kenderdine pointed out, has had thousands of gas leaks reported in the last few years, compared with just a handful in similarly sized Indianapolis, which modernized its pipes a few years ago.

The DOE’s Quadrennial Energy Review, Kenderdine said, includes 63 specific recommendations, which would likely have a total cost of $10 billion to $12 billion over the next decade. But there are great opportunities for improvements, particularly in the developing world, she said, where in many cases it may be possible to move directly into more efficient, modern generating and distribution systems.

Such developments, Kenderdine said, can “make a huge difference in people’s lives.”
The C3E symposium and awards program is a partnership of DOE and MITEI, under the auspices of the multi-governmental Clean Energy Ministerial.

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Streamlining mobile image processing MIT News Office

Technique for mobile image processing in the cloud cuts bandwidth use by more than 98 percent.
Larry Hardesty | MIT News Office 
November 13, 2015

As smartphones become people’s primary computers and their primary cameras, there is growing demand for mobile versions of image-processing applications.

Image processing, however, can be computationally intensive and could quickly drain a cellphone’s battery. Some mobile applications try to solve this problem by sending image files to a central server, which processes the images and sends them back. But with large images, this introduces significant delays and could incur costs for increased data usage.

At the Siggraph Asia conference last week, researchers from MIT, Stanford University, and Adobe Systems presented a system that, in experiments, reduced the bandwidth consumed by server-based image processing by as much as 98.5 percent, and the power consumption by as much as 85 percent.
The system sends the server a highly compressed version of an image, and the server sends back an even smaller file, which contains simple instructions for modifying the original image.

Michaël Gharbi, a graduate student in electrical engineering and computer science at MIT and first author on the Siggraph paper, says that the technique could become more useful as image-processing algorithms become more sophisticated.

“We see more and more new algorithms that leverage large databases to take a decision on the pixel,” Gharbi says. “These kinds of algorithm don’t do a very complex transform if you go to a local scale on the image, but they still require a lot of computation and access to the data. So that’s the kind of operation you would need to do on the cloud.”

One example, Gharbi says, is recent work at MIT that transfers the visual styles of famous portrait photographers to cellphone snapshots. Other researchers, he says, have experimented with algorithms for changing the apparent time of day at which photos were taken.

Joining Gharbi on the new paper are his thesis advisor, Frédo Durand, a professor of computer science and engineering; YiChang Shih, who received his PhD in electrical engineering and computer science from MIT in March; Gaurav Chaurasia, a former postdoc in Durand’s group who’s now at Disney Research; Jonathan Ragan-Kelley, who has been a postdoc at Stanford since graduating from MIT in 2014; and Sylvain Paris, who was a postdoc with Durand before joining Adobe.
Bring the noise

The researchers’ system works with any alteration to the style of an image, like the types of “filters” popular on Instagram. It’s less effective with edits that change the image content — deleting a figure and then filling in the background, for instance.

To save bandwidth while uploading a file, the researchers’ system simply sends it as a very low-quality JPEG, the most common file format for digital images. All the cleverness is in the way the server processes the image.

The transmitted JPEG has a much lower resolution than the source image, which could lead to problems. A single reddish pixel in the JPEG, for instance, could stand in for a patch of pixels that in fact depict a subtle texture of red and purple bands. So the first thing the system does is introduce some high-frequency noise into the image, which effectively increases its resolution.
That extra resolution is basically meaningless — just some small, random, local variation of the pixel color in the compressed file. But it prevents the system from relying too heavily on color consistency in particular regions of the image when determining how to characterize its image transformations.
Patch work

Next, the system performs the desired manipulation of the image — heightening contrast, shifting the color spectrum, sharpening edges, or the like.

Then the system breaks the image into chunks — of, say, 64 by 64 pixels. For each chunk, it uses a machine-learning algorithm to characterize the effects of the manipulation according to a few basic parameters, most of which concern variations in the luminance, or brightness, of the pixels in the patch. The researchers’ best results came when they used about 25 parameters. So for each 64-by-64 pixel patch of the uploaded image, each pixel of which could have one of three values, the server sends back just 25 numbers.

The phone then performs the modifications described by those 25 numbers on its local, high-resolution copy of the image. To the naked eye, the results are virtually indistinguishable from direct manipulation of the high-resolution image. The bandwidth consumption, however, is only 1 to 2 percent of what it would have been.

Applying the modifications to the original image does require some extra computation on the phone, but that consumes neither as much time nor as much energy as uploading and downloading high-resolution files would. In the researchers’ experiments, the energy savings were generally between 50 and 85 percent, and the time savings between 50 and 70 percent.

“There are a lot of things that we’re coming up with at Adobe Research that take a long time to run on the phone,” says Geoffrey Oxholm, a research and innovation engineer at Adobe who was not involved in the project. “Or it’s a big hassle to optimize them for every single mobile platform, so it’s attractive to be able to optimize them really well on the server. It’s almost like cheating: You get to use a big huge server and not pay as much to use it.”

“On the stuff that we’ve tried it on, it’s working great,” Oxholm adds. “The fact that they look good enough is troublesome to me. I don’t really understand how this is possible. I think there’s probably some lesson buried deep in here about what realistic images look like.”

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