Everyone loves themes. Doesn’t matter if it’s a text editor or a smart display in the kitchen, we want to be able to easily customize its look and feel to our liking. When setting up a new device or piece of software, playing around with the available themes may be one of the first things you do without giving it much thought. After all, it’s not like picking the wrong one is going to do something crazy like silently delete all the files on your computer, right?
Unfortunately, that’s exactly what happened a few days ago to [JeansenVaars] while trying out a Plasma Global Theme from the KDE Store. According to their Reddit post, shortly after installing the “Gray Layout” theme for the popular Linux graphical environment, the system started behaving oddly and then prompted for a root password. Realizing something didn’t seem right they declined, but at that point, it was already too late for all of the personal files in their home directory.
With the recent string of lunar landing attempts, it’s interesting to consider how much things have changed – or stayed the same – since the first soft landing attempts in the 1960s with the US Ranger and USSR Luna landers. During the 1950s the possibility of landing a spacecraft on the Moon’s surface was investigated and attempted by both the US and USSR. This resulted in a number of lunar lander missions in the 1960s, with the US’s Ranger 3 and 5 missing the Moon, Ranger 4 nearly missing it but instead crashing into the far side of the Moon, and eventually the USSR’s Luna 9 making the first touchdown on the lunar surface in 1966 after a string of USSR mission failures.
What’s perhaps most interesting was how these first US and USSR spacecraft managed to touch down, with Luna 9 opting to inflate a landing airbag and bounce until it came to a halt. This approach had doomed Luna 8, as its airbag got punctured during inflating, causing a hard crash. Meanwhile the US’s Surveyor 1 was the first US spacecraft to land on the Moon, opting to use a solid-fuel retrorocket to slow the craft down and three liquid-fueled vernier thrusters to prepare it for a drop down from 3.4 meters onto the lunar surface.
Now, nearly 60 years later, the landers we sent regularly make it to the lunar surface, but more often than not end up crashing or toppling over into awkward positions. How much have lunar landings really changed?
Nerf blasters are fun toys, to be sure. However, they’re limited by factors like price and safety and what Hasbro thinks parents will put up with. Few caregivers would ever countenance a build like this one from [ItllProbablyWork].
It’s a blaster designed to fire 48 darts in a second or so, or a truly ludicrous 288 Nerf balls. Like so many rapid fire blaster designs, it’s based on a pair of rotating wheels which fling darts out at rapid speed. The trick to the rapid fire ability is the delivery of ammunition. In this case, the blaster has a rotating drum of 12 barrels, which can each be loaded with 4 darts or 24 balls. As the drum rotates into position, a trigger mechanism unlatches a spring which forces the contents of the barrel out through the wheels and on to the target.
It’s mostly pretty good with darts, but with balls, it tends to send them flying everywhere, including jamming a bunch into the blaster’s internals. It is very funny to watch, though.
It used to be that nearly every home had at least one decent high-voltage power supply. Of course, it was dedicated to accelerating electrons and slamming them into phosphors so we could bathe ourselves in X-rays (not really) while watching Howdy Doody. These days the trusty tube has been replaced with LEDs and liquid crystals, which is a shame because there’s so much fun to be had with tens of thousands of volts at your disposal.
That’s the impetus behind this inexpensive high-voltage power supply by [Sebastian] over at Baltic Labs. The heavy lifting for this build is done by a commercially available power supply for a 50-watt CO2 laser tube, manufactured — or at least branded — by VEVOR, a company that seems intent on becoming the “Harbor Freight of everything.” It’s a bold choice given the brand’s somewhat questionable reputation for quality, but the build quality on the supply seems decent, at least from the outside. [Sebastian] mounted the supply inside a rack-mount case, as one does, and provided some basic controls, including the obligatory scary-looking toggle switch with safety cover. A pair of ammeters show current and voltage, the latter with the help of a high-voltage resistor rated at 1 gigaohm (!). The high-voltage feedthrough on the front panel is a little dodgy — a simple rubber grommet — but along with the insulation on the high-voltage output lead, it seems to be enough.
The power supply’s 30 kV output is plenty for [Sebastian]’s current needs, which from the video below appear to mainly include spark gap experiments. He does mention that 50 kV commercial supplies are available too, but it would be tough to do that for the $150 or so he spent on this one. There are other ways to go, of course — [Niklas] over at Advanced Tinkering recently shared his design for a more scratch-built high-voltage supply that’s pretty cool too. Whatever you do, though, be careful; we’ve been bitten by a 50 kV flyback supply before and it’s no joke.
Who’d have thought that $30 doorbell cameras would end up being security liabilities? That’s the somewhat obvious conclusion reached by Consumer Reports after looking at some entry-level doorbell cameras available through the usual outfits and finding glaring security gaps which are totally not intentional in any way.
All these cameras appear to be the same basic hardware inside different enclosures, most supporting the same mobile app. Our favorite “exploit” for these cameras is the ability to put them into a pairing mode with the app, sometimes by pressing a public-facing button. Slightly more technically challenging would be accessing images from the app using the camera’s serial number, or finding file names being passed in plain text while sniffing network traffic. And that’s just the problems CR identified; who knows what else lurks under the covers? Some retailers have stopped offering these things, others have yet to, so buyer beware.
Speaking of our techno-dystopian surveillance state, if you’ve had it with the frustrations and expense of printers, has Hewlett-Packard got a deal for you. They want you to never own a printer again, preferring that you rent it from them instead. Their “All-In Plan” launched this week, which for $6.99 a month will set up up with an HP Envy inkjet printer, ink deliveries, and 24/7 tech support. It doesn’t appear that paper is included in the deal, so you’re on your own for that, but fear not — you won’t go through much since the entry-level plan only allows 20 prints per month. Plans scale up to 700 prints per month from an OfficeJet Pro for the low, low price of $36. The kicker, of course, is that your their printer has to be connected to the Internet, and HP can pretty much brick the thing anytime they want to. The terms of service also explicitly state that they’ll be sending your information to advertising partners, so that’ll be fun. This scheme hearkens back to the old pre-breakup days of AT&T, where you rented your phone from the phone company. That model made a lot more sense when the phone (probably) wasn’t listening in on everything you do. This just seems like asking for trouble.
It’s been a while since Ingenuity‘s final rough landing on Mars permanently grounded the overachieving helicopter, long enough that it’s time for the post-mortem analyses to begin. The first photographic evidence we had was a shadowgram from one of the helicopter’s navigational cameras, showing damage to at least one of the rotor tips, presumably from contact with the ground. Then we were treated to a long-distance shot from Ingenuity‘s rover buddy Perseverance, which trained its MASTCAM instruments on the crash zone and gave us a wide view of its lonely resting place.
Now, geovisual design student [Simeon Schmauβ] has taken long shots made with the rover’s SuperCam instrument and processed them into amazingly detailed closeups, which show just how extensive the damage really is. One rotor blade sheared clean off on contact, flying 15 meters before gouging a hole in the regolith. Another blade looks to be about half gone, while the remaining two blades show the damaged tips we’ve already seen. That the helicopter is still on its feet given the obvious violence of the crash is amazing, as well as an incredible piece of luck, since it means the craft’s solar panel is pointing in roughly the right direction to keep it powered up.
There are many benefits to learning to fly an airplane, drive a racing car, or operate some complex piece of machinery. Ideally, you’d do so in a perfectly safe environment, even when the instructor decides to flip on a number of disaster options and you find your method of transportation careening towards the ground, or the refinery column you’re monitoring indicating that it’s mere seconds away from going critical and wiping out itself and half the refinery with it.
Still, we send inexperienced drivers in cars onto the roads each day as they either work towards getting their driving license, or have passed their driving exam and are working towards gaining experience. It is this inexperience with dangerous situations and tendency to underestimate them which is among the primary factors why new teenage drivers are much more likely to end up in crashes, with the 16-19 age group having a fatal crash nearly three times as high as drivers aged 20 and up.
After an initial surge in car driving simulators being used for students during the 1950s and 1960s, it now appears that we might see them return in a modern format.
Imagine you’re a commando, doing some big secret mission on the continent in the midst of World War II. You need to hook up some wires to your explosive charges, and time is of the essence. Do you bust out the trusty Weller and see if those petulant Axis chaps will let you plug it in somewhere? No! You use a pyrotechnic self-soldering sleeve, as [Our Own Devices] explains.
Like so many British inventions during the war, the sleeves really are ingenious. They were developed by the Special Operation Executive, an organization charged with sabotage and subversion operations in then-occupied Europe.
The soldering sleeves were designed to make electrical connections between detonators and firing wires for explosives. The sleeves consist of a copper tube through which wires to be joined are fed, with a lump of solder in the middle. The assembly is covered in pyrotechnic material with a safety match-style starter chemical dosed on top. Using the sleeves is simple. First, two stripped wires are fed into either end of the copper tube. The starter the sleeve is then ignited using the box, just like striking a match. The pyrotechnic material then gets red hot, melting the solder and making the connection.
It’s well worth watching the video to see how these field-expedient devices actually work. We’ve explored the use of more-typical solder sleeves before, too. Video after the break.
