This is an interview with Duolingo engineer Franklin Ditzler. He's not a smooth marketing guy getting all rah-rah about the company and what it does, just a coder who enjoys his job and seems to like where he works and what he's doing. Note that Duolingo is a free language teaching tool, and they seem determined to keep it free for language students by selling crowdsourced translation services to companies like CNN and BuzzFeed.

Duolingo founder and CEO Luis von Ahn is an associate professor in the Carnegie Mellon University Computer Science Department, and was one of the original developers behind reCAPTCHA. Google acquired ReCAPTCHA in 2009 for "an undisclosed sum," a bit of history that led TechCrunch to speculate back in 2011 that Google would buy Duolingo within six months -- which didn't happen. But don't despair. It's still possible that Google (or another big company) might absorb Duolingo. We'll just have to wait and see -- and possibly improve our foreign language skills while we wait. (Alternate Video Link)

Project Tango is part of Google's Advanced Technology and Projects group (ATAP), which Wikipedia says was "...formerly a division of Motorola." Tango's goal is "to give mobile devices a human-scale understanding of space and motion." We humans and our forebears have spent millions of years learning to sense our surroundings, not as a set of static 2D images, but in 3D with motion. This YouTube video starring Johnny Lee, the Tango project lead Tim interviewed at Google I/O 2014, gives you some decent insight into Project Tango's goals -- in addition to our video, that is. (Alternate Slashdot Video Link)

The original Mayday PAC goal was to raise $1 million. Now Larry is working on a second -- and more ambitious -- goal: To raise $5 million by July 4. We called for your questions on June 23, and you sent a bunch of them. This time, instead of using email, we used Google Hangout to ask via video, with an attached transcript for those who can't or won't watch the video. In today's video, Larry tells us that some of the impetus for Mayday PAC came from the late Aaron Swartz, and goes deeper into the group's goals and hopes than he did in yesterday's video. (Alternate Video Link)

We've mentioned this interesting PAC more than once, including when Steve Wozniak endorsed it. The original Mayday PAC goal was to raise $1 million. Now Larry is working on a second -- and more ambitious -- goal: To raise $5 million by July 4. We called for your questions on June 23, and got a bunch of them. This time, instead of asking via email, we used Google Hangout to ask via video. Here's a quote from the Mayday website:'We are a crowdfunded Super PAC to end all Super PACs. Ironic? Yes. Embrace the irony. We’re kickstarting a Super PAC big enough to make it possible to win a Congress committed to fundamental reform by 2016. We set fundraising goals and then crowdfund those goals." Check the Mayday About page and you'll see that a whole bunch of Internet and coding luminaries are on board. You may also notice that they span the political spectrum; this is totally not a partisan effort. | Another quote from the website: "Wealthy funders are holding our democracy hostage. We want to pay the ransom and get it back." Is this an achievable goal? We'll never know if we don't try. | This is Part 1 of a 2-part video. (Alternate Video Link) Update: 07/02 23:42 GMT by T : Here's a link to part 2 of the video, too.

The Skysense website says, 'Save time and manage your drone operations remotely: whenever the batteries run out, land on a Skysense Charging Pad and take off as soon as the batteries are recharged. Without ever leaving the office.' That certainly sounds convenient. Since it looks like everybody and her dog is jumping on the flying drone bandwagon, the next step is obviously charging the things without human intervention. We're talking about battery-powered ones, of course, like the multicopter drones that are starting to be used for things like pipeline inspection, mapmaking, and security alarm response. Sadly, using drones for beer delivery is currently against the law in the USA, as are the Burrito Bomber and the much-ballyhooed Amazon Prime Air drone delivery system. All this may change in the next few years as the FAA figures out how to regulate the many commercial drones that will inevitably be zipping through our skies, landing on pads to recharge themselves, and continuing their missions without human intervention. The next step in drone automation will probably be using driverless ground vehicles as drone launching and control stations. Shockingly, there aren't a dozen Kickstarter projects raising money to build automated ground support systems for automated flying drones already, but surely they'll show up before long. (Alternate Video Link)

Their main claim: "Sigsense Sensors are field-switchable sensing modules which replace the current generation of single purpose instruments. All Sigsense Sensors connect to the Sigsense Wireless Dock through a common interface. This portability and convenience allows workers to always carry the right instrument for the job." In other words, a technician in a food manufacturing plant doesn't need to carry a humidity-measuring tool, a multimeter, a signal strength meter, and four or five other measuring tools, to the point where he's got a backpack full of instrumentation or a rolling a cart full of measuring devices. That technician can now (in theory) carry a single, wireless sensor body, and put the sensors he needs on it as easily as you change heads on an electric hair trimmer. Check their blurb on AngelList for more about what this company is up to, and note that they are going way beyond making one measurement at a time. They're talking about collecting instrument data, along with tracking technicians, and sending all this data to the cloud, where you can do with it as you wish. But not today. The website says they will have products available "soon." (Alternate Video Link)

"Otherlab," says their projects page, "is a private Research and Development company with a number of core competencies. We welcome industrial partnerships and commercialization partners. We have worked with dozens of companies globally from small start-ups to multi-nationals and Fortune 500 businesses. We develop enabling new technologies through an emphasis on prototyping coupled to rigorous physics simulation and mathematical models. We develop our own design tools because it's lonely at the frontier and to create new things and ideas, you often have to create the tools to design them." | One of their projects is building low-cost, inflatable exoskeletons that can be used as prosthetics or -- one presumes -- as strength multipliers for people who have working limbs. This is the project today's interviewee, Tim Swift, is working on. (Alternate Video Link)

Modular Science is something Tim Lord spotted at last month's O'Reilly Solid Conference in San Francisco. Its founder, Peter Sand, has a Ph.D. in Computer Science from MIT. He's scheduled to speak at this year's OSCON, and his speaker blurb for that conference says, "He is the founder of ManyLabs, a nonprofit focused on teaching math and science using sensors and simulations. Peter also founded Modular Science, a company working on hardware and software tools for science labs. He has given talks at Science Hack Day, Launch Edu, and multiple academic conferences, including SIGGRAPH." And now he's also been interviewed on Slashdot. Note that there are plenty of lab automation systems out there. Peter is working on one that is not only "an order of magnitude cheaper" than similar devices, but is also easy to modify and expand. It's the sort of system that would fit well not just in a college-level lab, but in a high school lab or a local makerspace. (Alternate Video Link)

Two gyros under the seat keep this vehicle standing up at a stop, which is easier on the driver's legs than putting a foot down the way you do while riding most motorcycles. And no vroom-vroom sound, either. This is an electric motorcycle. The prototype you see in the video gets up to around 20 MPH, but production models are supposed to hit 100 MPH, and go as far as a Tesla S on 1/6 the juice. So little tiny batteries are all the Lit C-1 needs to drive (up to) 200 miles with the gyros spinning merrily away -- keeping the C-1 upright even in crashes, as a simulation in this Lit Motors YouTube video shows. They claim to have more than 200 pre-orders against a projected retail price of $24,000, which is not shabby for a company that hasn't made a single production vehicle so far. (Alternate Video Link)

Steve Delaire is making a 3-D printer that uses steel instead of plastic. Specifically, he's using TIG welding to build up layers of steel, just as most 3-D printers build up layers of plastic. He says he's "still working it out," but eventually hopes to use 3-D welding to make larger than life art pieces that are strong enough to be placed safely in public areas such as parks, where children are likely to climb on them. Steve's blog is called Molten3D, and it's a diary of his work, including the problems he encounters and how he overcomes them. He's not the only one doing metal 3-D printing; a Texas company has even made a printed metal gun. So there's plenty of people working in the field of what we really should call "additive manufacturing" instead of "3-D printing." But whatever you call it, every year we see this kind of process being used to make stronger and more complicated shapes, using an ever-increased variety of materials in ways that have been developed since this seminal paper, Liquid Metal Jetting for Printing Metal Parts, was written in 1997. (Alternate Video Link)