A couple of weeks ago you had the chance to ask Khan Academy lead developer Ben Kamens about the future of online education and the academy itself. Below you'll find his answers to the questions we sent and a few extra that he found interesting.

Imagine not being able to move a mouse or use a keyboard to control your computer. Frustrating, right? A company Timothy Lord found at CES named Eyetech has a solution for this problem: an eye tracker system that can control your computer or TV (or whatever) purely through eye movements. This isn't something you buy on a whim; the system costs $3000. That's a lot, but Eyetech claims they were the first ones to produce a high-accuracy eye tracker for less then $20,000. Obviously, this is a boon to profoundly disabled people. But Eyetech's Keith Jackson says, in the video, that they also have customers who use Eyetech instead of a mouse because of carpal tunnel syndrome, and that with voice recognition and on-screen keyboards -- and Eyetech, of course -- you can use your computer without (literally) lifting a finger.

Last week you had a chance to ask former Republican staffer Derek Khanna about his well publicized firing, copyright law, and the state of the government. Read below to see his answers to your questions.

Bennett Haselton writes "Evgeny Morozov's forthcoming book To Save Everything, Click Here describes how an overly helpful 'kitchen of the future' might stifle the learning process and threaten culinary innovation. True, but we could certainly do better than the current state of how-to directions (in cooking and most other subjects) that you can find today on Google. I suggest that the answer lies not in intelligent kitchen technology, but in designing an algorithm that would produce the best possible how-to directions -- where the 'best' directions are judged according to the results that are achieved by genuine beginners who attempt to follow the directions without help." Read below for the rest of Bennett's review.
Editor's Note: This article was not intended as a full review, but rather a commentary on one point in the book. The author's actual review of the book will appear in March.

William Volk may not be the world's oldest game designer, but he's up there. He started out as a play tester for Avalon Hill in 1979, and since then has worked for Activision and other major players in the game space. His current job is with PlayScreen, where he's working on their Word Carnivale iOS game, which is not violent at all. But over the years Volk has worked on slightly violent video games and has watched public outcries over video game violence since 1976. He's also tracked how much less violence we've seen since lead was removed from gasoline. (Editorial interjection: Aren't most remaining pockets of massive gun violence in cities where many poor kids grow up in apartments that have lead paint?) Due to technical problems during the interview, some of the conversation is missing, primarily about the recent spate of multiple murders. It seems, for instance, that Newtown shooter Adam Lanza was heavily into violent video games, which is sure to spark plenty of new discussion about how they affect players. But then again, as Volk reminded me in an email, "If people were influenced by video games, a majority of Facebook users would be farmers by now," a meme that has been floating around Facebook since last year, if not earlier.

Many of us have plug-in external batteries of one sort to recharge our smart phones when we're away from power outlets. Or we have gigantic aftermarket batteries that make our phones so fat they barely fit in our pockets. So there is this company, Lilliputian Power Systems, that is just starting to market a tiny, butane-powered fuel cell they call the Nectar that plugs into your cell phone (or whatever) through a USB port and supposedly charges it for up to two weeks. That's a lot better than an add-on battery. It looks expensive, although the power "pods" aren't too pricey at $19.99 for two. But wait a minute: Why aren't fuel cells, not internal combustion engines, the "range extenders" in plug-in hybrid cars? A decade back, fuel cells were going to revolutionize our power delivery and consumption systems. A cell phone charger is cute, but is that really all we can get fuel cells to do?

Republican staffer Derek Khanna was thrust into the spotlight in December for being fired after submitting a controversial brief titled: Three Myths about Copyright Law and Where to Start to Fix it. In the brief Khanna said: "Current copyright law does not merely distort some markets – rather it destroys entire markets," a view not very popular with Republicans in the House of Representatives. Since the firing, Khanna has continued to speak out on the need for copyright reform and most recently on the law against unlocking cellphones. Derek has graciously agreed to take some time to answer your questions about copyright reform and IP law. As usual, ask as many questions as you'd like, but please, one question per post.

"It uses a totally different process called Stereolithography," says Max Lobovsky, while other low-cost 3D printers use a process called FDM (fused deposition modeling). Max explains the differences between the two processes in the video, but what it comes down to in the real world is that his process can "do features down to 0.3 mm," which, he says, is much finer than you can get with FDM. It also seems that structures made with Stereolithography can be made stronger and can be machined more accurately than those made by the FDM process. So this is another step toward fully-useful home fabrication of... almost anything. So Formlabs and the company's initial product, the Form 1, are interesting. And surely there will be other "consumer" Stereolithography machines in the market before long, and prices for both the machine and the chemicals they use as raw materials will come down. Meanwhile, a company called 3D Systems is suing Formlabs for patent infringement. This isn't a nickel and dime deal; Formlabs raised $2,945,885 through Kickstarter, says TechCrunch in a story about the suit. And since their 3D printer is an order of magnitude less expensive than earlier Stereolithography machines and the company's future looks bright, 3D Systems might be better off taking a stock settlement than going for cash. They've settled with other alleged infringers before, so there's a precedent for that idea. Suit or no suit, Formlabs is going forward, building and shipping 3D printers as fast as they can -- and President Obama mentioned 3D printing in his State of the Union speech last night, which will surely help boost the entire industry, including Formlabs.

A few weeks ago you had the chance to ask Jack Horner about dinosaurs, science funding, and extinction level events. He's sent back his responses and commented: "Very impressive audience you have!" Read below for more flattery and his answers to your questions.

The Southern California Linux Expo (SCALE) is a venerable and-well regarded volunteer-run, regional Linux conference that draws over 2000 attendees and an amazing array of speakers and open source projects displaying their goodies in the exposition area. The tutorial and speech schedule is crazy-dense, with as many as 10 tracks going at once. Conference Chair Ilan Rabinovitch admits that there is no way you can take in all of SCALE. On the other hand, you are certain to find something new and interesting to learn if you have any interest at all in Open Source. And yes, we mean Open Source, not just Linux. This show has grown far beyond its humble roots as a get-together for a few local students interested in Linux. One last thing: When you register, if you use the promo code SLASH, the $70 pass for all three days is magically reduced to $35. And there are many other ways to get that discount or another one just like it, including affiliation with virtually any Southern California Open Source group or almost any Open Source project. SCALE is 100% non-profit, and wants to "spread the word," not make money.

Ben Kamens spent over 5 years at Fog Creek, eventually working his way up to VP of engineering. However, after watching one of Salman Khan's talks he started to volunteer his time at Khan Academy, and is now the lead developer. In-between providing a free world-class education for anyone anywhere, he's graciously agreed to answer some of your questions. As usual, ask as many questions as you'd like, but please, one question per post.

Nerval's Lobster writes "Gavin Newsom, former mayor of San Francisco and current lieutenant governor of California, argues in his new book Citizenville that citizens need to take the lead in solving society's problems, sidestepping government bureaucracy with a variety of technological tools. It's more efficient for those engineers and concerned citizens to take open government data and use it to build apps that serve a civic function—such as Google Earth, or a map that displays crime statistics—than for government to try and provide these tools itself. But Newsom doesn't limit his attacks on government bureaucracy to politicians; he also reserves some fire for the IT departments, which he views as an outdated relic. 'The traditional IT department, which set up and maintained complex, centralized services—networks, servers, computers, e-mail, printers—may be on its way out,' he writes. 'As we move toward the cloud and technology gets easier to use, we'll have less need for full-time teams of people to maintain our stuff.' Despite his advocacy of the cloud and collaboration, he's also ambivalent about Wikileaks. 'It has made government and diplomacy much more challenging and ultimately less honest,' he writes at one point, 'as people fear that their private communications might become public.' Nonetheless, he thinks WikiLeaks and its ilk are ultimately here to stay: 'It is happening, and it's going to keep happening, and it's going to intensify.' In the end, he feels the benefits of collaboration and openness outweigh the drawbacks." Keep reading for the rest of Nick's review.

Jon Brodkin writes "I’ve been a longtime fan of Brain Age. Mixed in among the standard-issue kill-everything-you-see/race/sports types of games that dominate gaming, Brain Age on the Nintendo DS always provided something unique, fun, and mentally stimulating. Doing math problems, counting syllables, recognizing patterns, and memorizing stuff was far more enjoyable than anyone would have expected in Brain Age: Train Your Brain in Minutes a Day, the game that kicked off the series seven years ago. Based on the research of neuroscientist Ryuta Kawashima, the exercises are designed to improve brain function—or at least give players the illusion that they’re getting smarter. Nintendo developed several sequels and spinoffs for the DS after that first game, and now a Nintendo 3DS-exclusive entry is here with Brain Age: Concentration Training, released as a download and physical media this past weekend for $30. Some improvements in gameplay are readily apparent. Handwriting recognition is significantly better. You play the game by holding the 3DS upright, rather than sideways like a book, and it works so well I wonder why previous Brain Age games used the wacky book-like layout at all." Read below to see what Jon thinks of the 3DS-exclusive version.

Simon Phipps is President of the Open Source Initiative (OSI) at least until March 31, 2013. He is one of 11 Directors, with Legal Counsel Mark Radcliffe and OSI President Emeritus Eric Raymond serving as advisers. The main function of the OSI is to safeguard The Open Source Definition and to make sure that all software licenses it approves adhere to it. Over the years, license approvals have become contentious more than once. Lately, however, the OSI has avoided acceptance of new licenses that substantially duplicate existing ones, so a lot of the license approval furor has died down. Several recent improvements in the OSI include opening the organization to individual memberships, and setting up the FLOSS Competence Center Network, both of which will no doubt help the OSI carry out and expand its primary mission: "Open Source community-building, education, and public advocacy to promote awareness and the importance of non-proprietary software."

With his trademark hat and beard, Dr. Robert Bakker is one of the most recognized paleontologists working today. Bakker was among the advisers for the movie Jurassic Park, and the character Dr. Robert Burke in the film The Lost World: Jurassic Park is based on him. He was one of the first to put forth the idea that some dinosaurs had feathers and were warm-blooded, and is credited with initiating the ongoing "dinosaur renaissance" in paleontology. Bakker is currently the curator of paleontology for the Houston Museum of Natural Science and the Director of the Morrison Natural History Museum in Colorado. He is also a Christian minister, who contends that there is no real conflict between religion and science, citing the writings and views of Saint Augustine as a guide on melding the two. Dr. Bakker has agreed to take some time from his writing and digging in order to answer your questions. As usual, ask as many questions as you'd like, but please, one question per post.

CES is not a political show, so it only drew one visible protester: Kelly Chong, who is mad at camera manufacturers for (he says) destroying his camera repair business. He managed to get mentioned in Forbes, in an article headlined CES: One Man's Protest Against The World's Camera Makers. And now he's getting three minutes and five seconds of fame on Slashdot. Is his protest justified? According to a 2012 article headlined How Nikon Is Killing Camera Repair, at least one major camera manufacturer now refuses to sell parts to independent repair shops. So Kelly Chong seems to have a legitimate beef. Will anyone listen to him? Will major, multinational camera manufacturers start selling parts to independent repair people again? And what about those of us who do (at least some of) our own repairs? Labor charges aside, it's often lots faster and easier to do a simple repair yourself than to box your camera up and send it somewhere, not to mention the waiting time for it to get back to you.

Reducing various items to a fine powder in one of his blenders earned Blendtec CEO Tom Dickson a cult following. One of, if not the greatest viral marketing campaigns of all time, the "Will It Blend?" series has been watched almost 221,000,000 times on YouTube. In addition to receiving many marketing awards, Tom and his blenders have been featured on The Tonight Show and the History Channel series Modern Marvels. He has agreed to take a break from pureeing household objects and answer your questions. As usual, you're invited to ask as many questions as you'd like, but please divide them, one question per post.

Shane Chen is an inventor who likes to make all kinds of things. For instance, he designed the frame and invented a special reflective surface for the screen you see in the background of the video below. But many of his inventions have to do with transportation, especially the kind of transportation that doubles as personal thrill ride, like a sail for paddleboats and an electric surfboard. At this year's CES, I spoke with Chen's daughter Ywanne about his latest rideable invention, which is for obvious reasons called the Solowheel. Her father's the one you can see demonstrating the device in the background; you can see trickier riding in this YouTube video. She says that of all her father's inventions, this is the one that came together most easily: his first stab at a powered unicycle just worked, and since then it's been polishing the experience and getting it to market. And "to market" isn't a dream; for about $1800, you can have an experience that's a bit more intense than a Segway. The Solowheel can climb hills of surprising steepness, as long as the rider is up for it. Coming down looks more challenging, though.

Better known by his stage name "The Amazing Randi", James Randi has made it his quest to "debunk psychic nonsense, disprove paranormal fakers, and squash claims of pseudoscience in order to bring the truth to the forefront." Randi worked as a popular magician most of his life and earned international fame in 1972 when he accused the famous psychic Uri Geller of being a fraud and challenged him to prove otherwise. In 1996 Randi founded The James Randi Educational Foundation (JREF) a non-profit organization whose mission includes "educating the public and the media on the dangers of accepting unproven claims, and to support research into paranormal claims in controlled scientific experimental conditions." He began offering $1000 in 1964 to anyone who could demonstrate proof of the paranormal. That amount has grown over the years, and the foundation's prize for such proof is now $1M. Around 1000 people have tried to claim the prize so far without success. Randi has agreed to take a break from busting ghostbusters and giving psychic healers a taste of their own medicine in order to answer your questions. As usual, you're invited to ask as many questions as you'd like, but please divide them, one question per post.

Jakob Perry, today's interviewee, is a volunteer who helps make LinuxFest Northwest happen. This is an event produced by the Bellingham Linux Users Group that "has been a tradition in Bellingham, WA since 2000." Bellingham is a small town about a 1.5 hour drive away from Seattle, and a shorter distance from Vancouver, Canada. Last year they had 1200 people. They have a core group of about 10 year-round volunteers, with as many as 60 participating in the event itself, many of whom are students at Bellingham Technical College, which is where LinuxFest Northwest is held.