Larry Tesler, a computer scientist who created the terms "cut," "copy," and "paste," has passed away at the age of 74. Gizmodo reports: Born in 1945 in New York, Tesler went on to study computer science at Stanford University, and after graduation he dabbled in artificial intelligence research (long before it became a deeply concerning tool) and became involved in the anti-war and anti-corporate monopoly movements, with companies like IBM as one of his deserving targets. In 1973 Tesler took a job at the Xerox Palo Alto Research Center (PARC) where he worked until 1980. Xerox PARC is famously known for developing the mouse-driven graphical user interface we now all take for granted, and during his time at the lab Tesler worked with Tim Mott to create a word processor called Gypsy that is best known for coining the terms "cut," "copy," and "paste" when it comes to commands for removing, duplicating, or repositioning chunks of text.

Xerox PARC is also well known for not capitalizing on the groundbreaking research it did in terms of personal computing, so in 1980 Tesler transitioned to Apple Computer where he worked until 1997. Over the years he held countless positions at the company including Vice President of AppleNet (Apple's in-house local area networking system that was eventually canceled), and even served as Apple's Chief Scientist, a position that at one time was held by Steve Wozniak, before eventually leaving the company.

In addition to his contributions to some of Apple's most famous hardware, Tesler was also known for his efforts to make software and user interfaces more accessible. In addition to the now ubiquitous "cut," "copy," and "paste" terminologies, Tesler was also an advocate for an approach to UI design known as modeless computing, which is reflected in his personal website. In essence, it ensures that user actions remain consistent throughout an operating system's various functions and apps. When they've opened a word processor, for instance, users now just automatically assume that hitting any of the alphanumeric keys on their keyboard will result in that character showing up on-screen at the cursor's insertion point. But there was a time when word processors could be switched between multiple modes where typing on the keyboard would either add characters to a document or alternately allow functional commands to be entered.

Slashdot readers fahrbot-bot and operator_error share a report from Phys.Org: Scientists at the University of Massachusetts Amherst have developed a device that uses a natural protein to create electricity from moisture in the air, a new technology they say could have significant implications for the future of renewable energy, climate change and in the future of medicine. As reported today in Nature, the laboratories of electrical engineer Jun Yao and microbiologist Derek Lovley at UMass Amherst have created a device they call an "Air-gen," or air-powered generator, with electrically conductive protein nanowires produced by the microbe Geobacter. The Air-gen connects electrodes to the protein nanowires in such a way that electrical current is generated from the water vapor naturally present in the atmosphere.

The new technology developed in Yao's lab is non-polluting, renewable and low-cost. It can generate power even in areas with extremely low humidity such as the Sahara Desert. It has significant advantages over other forms of renewable energy including solar and wind, Lovley says, because unlike these other renewable energy sources, the Air-gen does not require sunlight or wind, and "it even works indoors." The Air-gen device requires only a thin film of protein nanowires less than 10 microns thick, the researchers explain. The bottom of the film rests on an electrode, while a smaller electrode that covers only part of the nanowire film sits on top. The film adsorbs water vapor from the atmosphere. A combination of the electrical conductivity and surface chemistry of the protein nanowires, coupled with the fine pores between the nanowires within the film, establishes the conditions that generate an electrical current between the two electrodes. "We are literally making electricity out of thin air," says Yao. "The Air-gen generates clean energy 24/7." Lovely adds, "It's the most amazing and exciting application of protein nanowires yet."

The current generation of Air-gen devices can power small electronics, and they are expected to be brought to commercial scale soon.

Samsung Electronics semiconductor manufacturing division has won a contract to make new Qualcomm 5G chips using its most advanced chip-making technology, Reuters reported Tuesday, citing sources familiar with the matter said, boosting the Korean firm's efforts to gain market share against rival Taiwan Semiconductor Manufacturing. From the report: Samsung will fabricate at least some of Qualcomm's X60 modem chips, which will connect devices such as smart phones to 5G wireless data networks. The X60 will be made on Samsung's 5-nanometer process, the sources said, which makes the chips smaller and more power-efficient than previous generations. One of the sources said TSMC is also expected to fabricate 5-nanometer modems for Qualcomm. Samsung and Qualcomm declined to comment, and TSMC did not immediately respond to a request for comment. Best known among consumers for its phones and other electronic devices, Samsung is the world's second-biggest chip manufacturer through its foundry division, self-supplying many of its own mobile phone parts and also fabricating chips for outside customers such as IBM and Nvidia, among others.

The Trump administration is considering changing U.S. regulations to allow it to block shipments of chips to Huawei from companies such as Taiwan's TSMC, the world's largest contract chipmaker. Reuters reports: New restrictions on commerce with China's Huawei are among several options to be considered at high-level U.S. meetings this week and next. The chip proposal has been drafted but its approval is far from certain, one of the sources said. The measure would be a blow to the world's no. 2 smartphone maker as well as to TSMC, a major producer of chips for Huawei's HiSilicon unit and mobile phone rivals Apple and Qualcomm.

"What they're trying to do is make sure that no chips go to Huawei that they can possibly control," the second source said. To target global chip sales to Huawei, U.S. authorities would alter the Foreign Direct Product Rule, which subjects some foreign-made goods based on U.S. technology or software to U.S. regulations. Under the draft proposal, the U.S. government would force foreign companies that use U.S. chipmaking equipment to seek a U.S. license before supplying Huawei -- a major expansion of export control authority that could anger U.S. allies worldwide.

An anonymous reader quotes a report from Ars Technica: YouTuber JerryRigEverything regularly does destructive durability tests on phones, partly by attacking a device with a set of Mohs picks. These pointy metal tools that are calibrated to the Mohs scale of mineral hardness allow a user to determine the hardness of a surface by doing a scratch test. You start with the softest pick and work your way up the set until you find something that can scratch the surface you're testing. A modern smartphone with Corning's Gorilla Glass scratches at level 6 on the Mohs hardness scale. The Galaxy Z Flip features a first-of-its-kind flexible glass cover that Samsung calls "Ultra-Thin Glass." Until now, foldables have had to suffer through life with plastic display covers, which scratch easily, don't provide much protection, and just like a resistive touchscreen, feel bad to swipe around on, thanks to the squishy pliability of the display. With this new invention of flexible glass, the Z Flip promised a return to a hard, smooth, scratch-resistant display surface.

So how did the Z Flip fare against JerryRigEverything's Mohs picks? It scratches at level 2, the same level as the plastic-covered Galaxy Fold and Moto Razr. You can actually leave marks on the surface with a fingernail! This is not what Samsung was promising. Samsung sent The Verge a response to the video, reiterating that the display is actually "glass." "Galaxy Z Flip features an Infinity Flex Display with Samsung's Ultra Thin Glass (UTG) to deliver a sleek, premium look and offer an immersive viewing experience," Samsung told the site. "Samsung's first-of-its-kind UTG technology is different from other Galaxy flagship devices. While the display does bend, it should be handled with care. Also, Galaxy Z Flip has a protective layer on top of the UTG similar to Galaxy Fold." In Samsung's official Z Flip videos, the company shows a plastic "protective layer" going on top of the glass display. But as Ars Technica notes, this layer is not removable and JerryRigEverything's video shows that the underlying "glass" layer doesn't provide protection from punctures, either.

With that said, "One Twitter user cracked their Galaxy Z Flip on the first fold, possibly due to cold weather," reports Ars. "So we know it can shatter, at least."

Recently a well-respected UI consulting firm (the Nielsen Norman Group) published their analysis of academic studies on the question of whether Dark Mode or Light Mode was better for reading? Cosima Piepenbrock and her colleagues at the Institut für Experimentelle Psychologie in Düsseldorf, Germany studied two groups of adults with normal (or corrected-to-normal) vision: young adults (18 to 33 years old) and older adults (60 to 85 years old). None of the participants suffered from any eye diseases (e.g., cataract)... Their results showed that light mode won across all dimensions: irrespective of age, the positive contrast polarity was better for both visual-acuity tasks and for proofreading tasks...

Another study, published in the journal Human Factors by the same research group, looked at how text size interacts with contrast polarity in a proofreading task. It found that the positive-polarity advantage increased linearly as the font size was decreased: namely, the smaller the font, the better it is for users to see the text in light mode. Interestingly, even though their performance was better in the light mode, participants in the study did not report any difference in their perception of text readability (e.g., their ability to focus on text) in light versus dark mode — which only reinforces the first rule of usability: don't listen to users...

While dark mode may present some advantages for some low-vision users — in particular, those with cloudy ocular media such as cataract, the research evidence points in the direction of an advantage of positive polarity for normal-vision users. In other words, in users with normal vision, light mode leads to better performance most of the time... These findings are best explained by the fact that, with positive contrast polarity, there is more overall light and so the pupil contracts more. As a result, there are fewer spherical aberrations, greater depth of field, and overall better ability to focus on details without tiring the eyes...

That being said, we strongly recommend that designers allow users to switch to dark mode if they want to — for three reasons: (1) there may be long-term effects associated with light mode; (2) some people with visual impairments will do better with dark mode; and (3) some users simply like dark mode better.
The long-term effects associated with light mode come from an "intriguing" 2018 study they found which argued that reading white text from a black screen or tablet "may be a way to inhibit myopia, while conventional black text on white background may stimulate myopia..."

The researchers wrote that myopia "is tightly linked to the educational status and is on the rise worldwide."

Long-time Slashdot reader lkcl writes: Michael Larabel, of Phoronix, writes that the OpenPower Foundation has released a license agreement for Hardware Vendors to implement the Power ISA RISC instruction set in their processors. Hugh Blemings, the Director of OpenPower, was responsible for ensuring that the EULA is favourable and friendly towards Libre and Open Hardware projects and businesses.

Of particular interest is that IBM's massive patent portfolio is automatically granted, royalty-free as long as two conditions apply: firstly, the hardware must be fully and properly Power ISA compliant, and secondly, the implementor must not "try it on" as a patent troll.

Innovation in the RISC space just got a little more interesting.
"Amidst the fully free and open RISC-V ISA making headway into the computing market, and ARM feeling pressured to loosen up its licensing, it seems they figured that it's best to join the party early," argues Hackaday.

"Billionaire Bill Gates has not commissioned a hydrogen-powered superyacht from designer Sinot," reports the BBC, citing their direct confirmation from the company itself. It has been widely reported that Mr Gates ordered a £500m ($644m) luxury vessel, based on the concept which was displayed in Monaco in 2019. Sinot said it had "no business relationship" with Bill Gates. It added that that the concept yacht, called Aqua, was "not linked" to either him or any of his representatives.

"Aqua is a concept under development and has not been sold to Mr. Gates," a spokeswoman said.
The Guardian has now removed their original article. But here's what they'd originally reported: Bill Gates has ordered the world's first hydrogen-powered superyacht, worth an estimated £500m ($644m) and featuring an infinity pool, helipad, spa and gym...

The boat has five decks and space to accommodate 14 guests and 31 crew members. In a further environmentally friendly feature, gel-fuelled fire bowls allow guests to stay warm outside without having to burn wood or coals.

But its most cutting-edge feature is tucked away below decks – two 28-tonne vacuum-sealed tanks that are cooled to -423F (-253C) and filled with liquid hydrogen, which powers the ship. The fuel will generate power for the two one-megawatt motors and propellors via on-board fuel cells, which combine hydrogen with oxygen to produce electricity. Water is a byproduct.

Ben Zhao and his wife, Heather Zheng, computer science professors at the University of Chicago, designed what they are calling a "bracelet of silence" that will jam the Echo or any other microphones in the vicinity from listening in on the wearer's conversations. The New York Times reports: The bracelet is like an anti-smartwatch, both in its cyberpunk aesthetic and in its purpose of defeating technology. A large, somewhat ungainly white cuff with spiky transducers, the bracelet has 24 speakers that emit ultrasonic signals when the wearer turns it on. The sound is imperceptible to most ears, with the possible exception of young people and dogs, but nearby microphones will detect the high-frequency sound instead of other noises. "It's so easy to record these days," Mr. Lopes said. "This is a useful defense. When you have something private to say, you can activate it in real time. When they play back the recording, the sound is going to be gone." During a phone interview, Mr. Lopes turned on the bracelet, resulting in static-like white noise for the listener on the other end. At this point, the bracelet is just a prototype. The researchers say that they could manufacture it for as little as $20, and that a handful of investors have asked them about commercializing it. "The 'bracelet of silence' is not the first device invented by researchers to stuff up digital assistants' ears," the report notes. "In 2018, two designers created Project Alias, an appendage that can be placed over a smart speaker to deafen it. But Ms. Zheng argues that a jammer should be portable to protect people as they move through different environments, given that you don't always know where a microphone is lurking."

"Other precursors to the bracelet include a 'jammer coat' designed by an Austrian architecture firm in 2014 to block radio waves that could collect information from a person's phone or credit cards," reports The New York Times. "In 2012, the artist Adam Harvey created silver-plated stealth wear garments that masked people's heat signature to protect them from the eyes of drones, as well as a line of makeup and hairstyles, called CV Dazzle, to thwart facial recognition cameras."

An anonymous reader quotes a report from Ars Technica: A 3D model is sliced up into hundreds of 2D horizontal layers and slowly built up, one layer at a time. This layer-by-layer process can take hours or even days, but what if we could print the entire model at once? A new technique demonstrated by researchers from Switzerland's Ecole polytechnique federale de Lausanne (EPFL) -- and further detailed in this Nature article -- does just that and can print an entire model in seconds. The new technique builds a model by hardening a photosensitive resin with a laser, not unlike existing stereolithography (SLA) printers. The big difference here is the application of tomographic techniques, the same used in x-rays and ultrasounds, that allows for rotational printing. Laser light is modulated with a DLP chip (just like in old rear-projection HDTVs) and is blasted into a container full of resin. The laser covers the entire build volume, and the container of resin actually rotates while it's being exposed to the light. The laser projects the model at different rotational perspectives, which is synced up with the spinning resin, and a whole 3D model can be produced in seconds.

The EPFL writes, "The system is currently capable of making two-centimeter structures with a precision of 80 micrometers, about the same as the diameter of a strand of hair. But as the team develops new devices, they should be able to build much bigger objects, potentially up to 15 centimeters." In this first public demonstration, the build volume is 16mm x 16mm x 20mm, making it one of the smallest 3D printers on earth. An 80 um resolution is also nothing to write home about and can be bested by ~$500 consumer SLA printers. It is very fast, though, and the technique is just getting started. The researchers have set up a spin-off company called "Readily 3D" to develop and market the technology.

Thelasko shares a report from Automotive News Europe: Jaguar Land Rover is pausing production of the Jaguar I-Pace electric SUV due to battery supply issues from LG Chem's Poland plant. JLR said it has adjusted production schedules of the model due to temporary supplier scheduling issues. "We are working with the supplier to resolve this and minimize impact on customer orders," JLR said. JLR did not name the supplier [A source familiar with the matter told Automotive News Europe that the battery supplier is LG Chem]. It also did not say when the production pause would start. The I-Pace is a rival to the Tesla Model X, featuring a large 90kWh battery and a range of about 377 km (234 miles). According to The Times newspaper, production of the I-Pace will stop for a week starting on Monday, Feb. 17.

An anonymous reader quotes a report from IEEE Spectrum: A test by Penumbra Brands to measure how much radiofrequency energy an iPhone 11 Pro gives off found that the phone emits more than twice the amount allowable by the U.S. Federal Communications Commission. The FCC measures exposure to RF energy as the amount of wireless power a person absorbs for each kilogram of their body. The agency calls this the specific absorption rate, or SAR. For a cellphone, the FCC's threshold of safe exposure is 1.6 watts per kilogram. Penumbra's test found that an iPhone 11 Pro emitted 3.8 W/kg.

Ryan McCaughey, Penumbra's chief technology officer, said the test was a follow up to an investigation conducted by the Chicago Tribune last year. The Tribune tested several generations of Apple, Samsung, and Motorola phones, and found that many exceeded the FCC's limit. Penumbra used RF Exposure Labs, an independent, accredited SAR testing lab for the tests (The Tribune also used the San Diego-based lab for its investigation). Penumbra was conducting the test, which also included testing an iPhone 7, to study its Alara phone cases, which the company says are designed to reduce RF exposure in a person. It's worth noting that when the FCC conducted a follow-up investigation they did not find evidence that any of the phones exceed SAR limits. "That said, while the Tribune and Penumbra both used off-the-shelf phones, the FCC largely tested phones supplied by the manufacturers, including Apple," adds IEEE Spectrum.

Joel Moskowitz, a researcher at UC Berkeley, says that could be because there's a systematic problem with RF Exposure Lab's testing methods, or Apple rigged the software in the provided test phones to ensure they didn't put out enough power to exceed the SAR limit. Either way, both McCaughey and Moskowitz agree that the FCC's RF exposure testing is woefully out of date, as the limits reflect what the FCC deemed safe 25 years ago.

An anonymous reader shares a report: It comes as no surprise that the guidance computers aboard the Apollo 11 spacecraft were impossibly primitive compared to the pocket computers we all carry around 50 years later. But on his website, an Apple developer analyzed the tech specs even further and found that even something as simple as a modern USB charger is packed with more processing power. Forrest Heller, a software developer who formerly worked on Occipital's Structure 3D scanner accessory for mobile devices, but who now works for Apple, broke down the numbers when it comes to the processing power, memory, and storage capacity of Google's 18W Pixel charger, Huawei's 40W SuperCharge, the Anker PowerPort Atom PD 2 charger, and the Apollo 11 guidance computer, also referred to as the AGC. It's not easy to directly compare those modern devices with the 50-year-old AGC, which was custom developed by NASA for controlling and automating the guidance and navigation systems aboard the Apollo 11 spacecraft.

In a time when computers were the size of giant rooms, the AGC was contained in a box just a few feet in length because it was one of the first computers to be made with integrated circuits. Instead of plopping in an off the shelf processor, NASA's engineers designed and built the AGC with somewhere around 5,600 electronic gates that were capable of performing nearly 40,000 simple mathematical calculations every second. While we measure processor speeds in gigahertz these days, the AGC chugged along at 1.024 MHz. By comparison, the Anker PowerPort Atom PD 2 USB-C charger includes a Cypress CYPD4225 processor running at 48 MHz with the twice the RAM of the AGC, and almost twice the storage space for software instructions.

An anonymous reader quotes a report from CNET: Nevada's Democratic Party said Thursday it plans to use iPads loaded with survey app Google Forms to calculate voting results in next week's caucuses. The system is an effort to avoid a repeat of the Iowa caucus chaos. The app will be loaded onto 2,000 iPads purchased by the party and distributed to precinct chairs, according to a memo signed by party Executive Director Alana Mounce seen by the Associated Press Thursday. Google's app will calculate and submit results electronically, while a second step will rely on submissions also being made by phone. Nevada's caucuses will be held on Feb. 22.

Qualcomm is making the case for why it didn't hurt competition in the smartphone chip business. "The company, represented by attorney Thomas Goldstein of the firm Goldstein & Russell, on Thursday appeared before the U.S. Court of Appeals for the Ninth Circuit in downtown San Francisco," reports CNET. "Qualcomm is hoping the appeals court will overturn a ruling by a district court judge that declared it to be a monopoly and ordered it to renegotiate its licensing contracts." From the report: Qualcomm during the hearing didn't dispute that it has a monopoly in 3G and 4G LTE chips. But it maintains that it didn't wield that power to harm competition. "What has gone wrong in the competitive process?" Goldstein said. "The answer is nothing." He noted that Qualcomm's business practices could be an issue of contract violations but not an antitrust issue. The US Federal Trade Commission, meanwhile, tried to make it clear how Qualcomm's "no license, no chip" policy undercut rivals and caused handset makers to shift business to Qualcomm. Brian Fletcher, an attorney who teaches at Stanford University, spoke for the FTC. He said Qualcomm is making it harder for competitors not because its policies have meant lower chip prices but "because it's demanding customers pay Qualcomm even when they decide to buy from rival suppliers."

The hearing is the latest twist in a legal saga that began three years ago when the FTC accused Qualcomm of operating a monopoly and forcing Apple and other customers to work with it exclusively. The FTC also accused the company of charging excessive licensing fees for its technology. As part of the district court's ruling, Qualcomm must submit compliance and monitoring reports for the next seven years and report to the FTC annually. Thursday's hearing marks Qualcomm's attempt to have that ruling overturned. The three appeals court judges likely won't make a decision for three months to over a year as they weigh the evidence.

They beat us at chess and trivia, supplant jobs by the thousands, and are about to be let loose on highways and roads as chauffeurs and couriers. Now, fresh signs of robot supremacy are emerging on Wall Street in the form of machine stock analysts that make more profitable investment choices than humans. From a report: At least, that's the upshot of one of the first studies of the subject, whose preliminary results were released in January. Buy recommendations peddled by robo-analysts, which supposedly mimic what traditional equity research departments do but faster and at lower costs, outperform their flesh-and-blood counterparts over the long run, according to Indiana University professors.

"Using this type of technology to make investment recommendations or to conduct investment analyses is going to become increasingly important," Kenneth Merkley, an associate professor of accounting and one of the authors, said by phone. Whether getting stock calls right is a critical mission of human analysts is debatable. Wall Street research departments serve a variety of functions, among them connecting investors with company executives and gathering earnings and other corporate data. While their buy, sell and hold recommendations still garner attention and can move stocks, the number of clients premising investment decisions off them is probably limited. The study looked at a small and still largely experimental branch of fintech, firms founded on the premise that digital technology does a better job than humans in making equity recommendations. While all analysts use computers, a handful of start-ups has been seeing if programs can handle every aspect of the stock-picking process.

An anonymous reader quotes a report from Ars Technica: A Philadelphia man has been freed after a federal appeals court ruled that his continued detention was violating federal law. Francis Rawls, a former police officer, had been in jail since 2015, when a federal judge held him in contempt for failing to decrypt two hard drives taken from his home. The government believes they contain child pornography.

After losing that appeal, Rawls raised another challenge: the federal statute that allows judges to hold witnesses in contempt for refusing to testify, passed in 1970, states that "in no event shall such confinement exceed eighteen months." The government argued that this provision didn't apply to Rawls because he was a suspect, not a witness. Also, the rule applies to a "proceeding before or ancillary to any court or grand jury." But because the government hadn't formally charged Rawls with a crime, the government argued, there was no court proceeding under way. Last week, a three-judge panel of the 3rd Circuit rejected this argument in a 2-1 vote. The court's two-judge majority held that Congress had intended for the 18-month limitation to apply broadly to any legal proceeding, not just a formal trial. And while Rawls was a suspect in the case, he was also a witness. The practical result is that, at least in federal court, someone can only be imprisoned for 18 months for refusing to open an encrypted device. The government says it has other evidence suggesting that Rawls possessed child pornography, "so prosecutors may be able to piece together enough evidence to convict him, even without access to his encrypted hard drives," the report adds. "One of the two judges who formed the 3rd Circuit's majority urged the trial court judge to consider the four years of imprisonment Rawls has already served if he eventually has to sentence Rawls after a child pornography conviction."

Nikola Motors on Monday unveiled a concept for a new electric pickup truck called the Badger. Engadget reports: Nikola plans to offer the Badger as both a purely battery-electric vehicle and as an electric/fuel-cell hybrid. The company claims the hybrid powertrain model will feature a maximum range of approximately 600 miles, while the battery model will be limited to 300 miles. It also claims the pickup will be able to tow up to 8,000 pounds and accelerate from 0 to 60 miles per hour in approximately 2.9 seconds. Those capabilities, if Nikola can deliver on them, would make the Badger mostly comparable to Tesla's Cybertruck. Since hydrogen fuel stations are few and far between, Nikola says it plans to build 700 hydrogen filling stations in the near future. "The company claims it has the first locations secured, but it won't announce them until later this quarter," adds Engadget.

Nikola will fully detail the Badger at its upcoming Nikola World 2020 event in September, at which point it will start accepting limited reservations as well.

Surprising absolutely nobody, Samsung officially announced the Galaxy Z Flip, its second stab at foldable phone, at its Unpacked event in San Francisco on Tuesday. From a report: The Z Flip is markedly different foldable than the Galaxy Fold, which launched to lukewarm reception and a whopping $1,980 price. Instead of a phone that unfolds open to a larger tablet-sized screen, the Galaxy Z Flip is a regular smartphone that folds closed into a smaller device. It's similar to the Motorola Razr. The Z Flip has a 6.7-inch OLED display that bends in half. Samsung says the "Infinity Flex Display" is the first one that is made of glass. Every foldable phone display has used plastic, which is more malleable, but less durable and scratch-resistant than glass. Underneath the folding screen, there's a Snapdragon 855+ chip. It's priced at $1,380 and starts shipping this Friday.

An anonymous reader quotes a report from New Atlas: Organic solar cells (OSCs) have a few advantages over other designs. They still collect energy from sunlight, but can be made more flexible, transparent (or at least semi-transparent) and can be tuned to only absorb certain wavelengths of light. That potentially makes them perfect for greenhouse roofing -- they can let most light through for the plants, while harvesting enough to offset a decent chunk of the facility's energy needs. "Plants only use some wavelengths of light for photosynthesis, and the idea is to create greenhouses that make energy from that unused light while allowing most of the photosynthetic band of light to pass through," says Brendan O'Connor, corresponding author of the study [from North Carolina State University]. "However, until now it wasn't clear how much energy a greenhouse could capture if it was using these semitransparent, wavelength selective, organic solar cells."

To begin to answer that question, the researchers modeled how much energy would be coming in from a greenhouse with OSCs in the roof, versus the amount of energy it would normally consume. The idea was to find the point where the greenhouse becomes energy neutral -- that is, it generates enough energy from the Sun to completely power itself. For this study, the theoretical greenhouses were modeled on the energy needed to grow tomatoes in three locations with different climates -- Arizona, North Carolina and Wisconsin. As a bonus, the OSCs are effective insulators too, helping maintain the right temperature. The team found that there would be a small hit to the amount of usable light the plants inside would receive, but the benefits would be worth it. In the famously sunny Arizona, for example, a greenhouse with OSCs installed could become energy neutral while blocking just 10 percent of the light the plants need. This shouldn't negatively affect the plants, the team says. In fact, the energy output could be doubled with just a little more light blocked. In North Carolina, sunlight is a little more sparse, so a greenhouse would need to block 20 percent of the photosynthetic light to become energy neutral. Chilly Wisconsin winters would be too much to ever achieve neutrality though, but these greenhouses could still generate almost half of their energy needs. The new study was published in the journal Joule.