Kritik sah

Sometimes claimed to give you wings, energy drinks can, at the very least, be used to make rockets fly. This is what [Nate Scovill] did in a recent video , where cans of the sugary stuff are processed to give a rocket its proverbial wings. The basic concept is so-called rocket candy , which uses the fact that sugar is a pretty decent fuel type that — when combined with an oxidizer like potassium nitrate — can be turned into solid rocket fuel. Naturally it’d be easiest to start off with a pure source of sucrose or sorbitol for the sugar, but what if you only have access to cans of sugary soda? Removing the moisture from the energy drink was the obvious first step, as water and rocket fuel aren’t a great mix. Adding and mixing potassium nitrate to the resulting thick syrup created the fuel-oxidizer mixture, also known as rocket fuel. This did take a detour involving removing the carbonation using a vacuum chamber, as CO 2 and fire do not really like each other e...

Steam power is a staple of the steampunk aesthetic, thermodynamics, and a checkpoint for the budding mechanical engineer studying heat cycles. But because food is largely made of water, steam is also common in the culinary arts. So it’s no surprise that when thermodynamics is applied to cooking, exciting things can happen.  This particular example of steam-powered culinary happenings is inspired by industrial potato-peeling machines. By adding high-pressure, high-temperature steam to a pressure vessel with potatoes inside, heat can transfer more easily to the inside of the potatoes. Because the pressure is so high, however, the water in the skin won’t boil. This is fundamentally the same concept as a pressure cooker. However, what’s different is that instead of a pressure cooker’s slow release, these industrial peeling machines rely on explosive decompression, flash boiling the water underneath the potato’s skin. This rapidly expanding steam rips away the ...

It’s a sci-fi trope that you can ‘scan for life signs’ and detect if there are humans — or suspiciously human-shaped aliens — present, but in real life it’s harder than that. [The Masked Bear]’s wifisense-pi project isn’t really scanning for signs of life, either, unless you happen to consider breathing a sign of life. Even then, it’s not detecting breathing per se, but the subtle motion that goes with it: it’s a very sensitive motion detector that relies on the fact that we fleshy bags of goo disturb WiFi signals with our presence, and motion alters those disturbances. We’d probably waste a lot of time watching the signal graphs on the WifiSense-Pi dashboard. The device uses an ESP32-S3 to measure the radio channel 100 times per second, while a Raspberry Pi 4 provides the signal processing muscle. It can detect the slightest motions, and even determine the presence of a perfectly still human by their breathing, though...

Remember Animusic? They were these incredible animated music videos with original tunes being played by computer-generated robots. Well, the MegCell Pulse might be the coolest robots-playing-music thing we’ve seen since Animusic . Built by [Bruce] over six years’ time, this futuristic wonder features two robots working in concert to play acoustic guitar, just like a pair of human hands would. You just feed them digital tablature, and off go the fraternal twins, with one doing the fretting, and the other doing the plucking via six individual plectrum. It’s digital music producing analog sound from a physical instrument. How does MegCell Pulse work? It’s essentially a system of gears, magnetic actuators, and arms, contained in a 3D-printed structure. The only real limitations are that it can’t traverse the entire fretboard, nor can it slide between frets. That said, you can absolutely buy one for your own guitar via [Bruce]’s modestly-goaled Kickstar...

After the Nintendo 3DS handheld console saw most its online services including the online store (eShop) taken offline not too long ago, it was only a matter of time before the demise of even the remaining paid services, such as the Pokémon Bank which Nintendo has now announced will be shutting down on February 25 of 2027. The ability to transfer the digital pocket monsters, or Pokémon, between physical systems has been a staple of the series since the early Gameboy days when a link cable would be all you needed to trade and catch’em’all, as they say in the trade. Naturally over time this Cloud-based aspect wormed its way into this series as well, starting with the 3DS and this continuing on the Nintendo Switch in the form of the Pokémon HOME app. With this paid service an avid Pokémon fan could collect up to 3,000 of these digital critters, move them between various Pokémon games and generally allow players to keep the same Pokémon with them across games. As noted by [K...

Doing anything on a frozen lake can carries some amount of risk. Nevertheless, every year events ranging from car racing to ice skating are held on them. As such, proper safety precautions are needed, the most important of which is ensuring the ice is thick enough to withstand the weight of whatever may be on it. This is done by cutting holes into the ice and measuring its depth in several locations. But this is a dangerous and imperfect process only giving a rough picture of actual thickness. So to solves these problems, a team of students at ETH Zurich made an ice measuring submersible drone.  The concept of ice measurement employed is, on paper, reasonably simple. When a sonar pulse is sent out, some of the energy will return off the bottom of the ice sheet, but some of it will pass through creating a second return. By measuring the difference in these two returns, the thickness can be calculate with a high degree of precision. Attach the sonar to a submersible and give it a positi...