Kritik sah

About a month ago, [Greenhill Forge] built a few solar panels to collect energy from the sun. Unlike solar photovoltaics, which turn sunlight directly into electricity, these were designed to gather solar thermal energy with air. These types of panels can gather a tremendous amount of energy for a very low cost, and although the first video only went into the theory of their operation, his latest video actually shows us how to use that energy in a practical way . The video starts by building a new solar panel, using upgraded materials and building methods compared to the previous versions which should improve the efficiency. There’s some data analysis of the performance, but at the end of the video [Greenhill Forge] actually hooks one of these up to a clothes dryer to explore its real-world efficacy. This process involves disconnecting the electric heater, removing one of the blower fans, and building a new flange to accept the heated air from the solar panel. A microcontroller k...

A fascinating aspect in evolutionary biology is that of convergent evolution — whereby similar structures and functions evolve independently from each other. The highly advanced nervous system of octopuses is a good example here, displaying levels of intelligence and capabilities far beyond those of other cephalopods and matching that of primates, despite no evolutionary link here. Exactly how octopuses developed this rather unique capability remained a mystery, though recent research by [Rishav Mitra] points at the rather unique ribosomes in these animals. Ribosomes are the molecular machinery at the core of each cell that enable the synthesis of proteins. Due to their highly crucial role, they tend to remain evolutionary unchanged, which makes the big change observed in the octopus (i.e. order Octopoda) in the form of this H88 rRNA break quite remarkable. Common octopus ( Octopus vulgaris ). (Credit: Albert Kok, Wikimedia ) This H88 break increases the accuracy of translate...

A problem facing the designers of event badges is this: what happens to the badge after the event? It’s one that designers have tried to solve in many ways with varying levels of success, whether that be by making it a dev board, a games console, a mesh-networked communicator, or as in the case of Electromagnetic Field, a continuing badge for future events. Ar BornHack 2026 they have taken a novel approach, by making it a useful desktop appliance . The BornHack Cyber Ægg is a half-egg-shaped badge with a 3D-printed case, and aside from its on-camp applications it’s both a desktop clock/calendar, and a MeshCore node. Produced with the assistance of the badge.team European badge makers, it’s an egg-shaped PCB with a Nordic nRF52840 at its heart, a Semtech LoRa module, and an e-paper display. On-site there’s a Tamagotchi-style virtual pet game, an event calender, and an RFID token game, but it’s the other two features that give it a life after the camp. The ...

In 1675, while transporting a barometer by night, the astronomer Jean Picard noticed a glow inside its glass tube, just above the mercury. As the mercury sloshed and splashed across the surface of the glass, a static electric charge had built up, which was discharging by ionizing the residual gas molecules inside the evacuated tube. [Styropyro] recreated this effect , and found that the dim glow could be made much stronger by adding some noble gas to the tube. It starts with a simple recreation: he took a volumetric flask, attached a narrow glass stem to the mouth, added some mercury to the flask, evacuated it with a vacuum pump, and sealed off the glass stem. This produced a faint glow when shaken, but it was only really visible under very low light. When [Styropyro] brought it near a Tesla coil, however, it did glow much more brightly. Backfilling an identical flask with neon to about 40 millitorr produced a much more spectacular result (a low pressure in the tube is necessary, bu...

Railroads might be a nineteenth century technology, but they’re still the backbone of cargo transportation in the 21st century. They’ve also far from run out of innovation, including this one which really just sounds like a hack: painting the rails white to beat the heat . In the old days, when rails were short and riveted together, this might have been unecesssary; all those joints allowed for a lot of flex. But when you have kilometers of continously welded rail, the thermal expansion starts to matter. A lot. Even if the rails haven’t bent and buckled from excess heat, their capacity goes down. Trains must therefore slow way, way down in hot weather, reducing the overall amount of freight the system can handle. So, how do you cool the million miles of metal that holds a country together? Paint. Simple white paint sprayed on the side of the rails can bring down temperatures 11 °C (20 °F), according to the Union Pacific Railroad, the first to try this in North Americ...

[Dr. Gough] bought a generic USB 3.0 hub on an Asian website. Surely, USB 3 is mature enough that even the cheapest hub will have some IC in it that will work well, right? You’d think so, but a little exploratory surgery showed that the only thing about this hub that was USB 3 were the blue port connectors . We have a few problem USB hubs ourselves, so it might be worth doing this to any you have lying around. The first clue: most of the connectors on the PCB only have four pins. On closer examination, the hub appears to be a USB 3.0 extension cable with a USB 2.0 hub made from two HS8836A chips. Not only are these USB 2-only, but all the ports on an HS8836A also share the same USB 1.1 bandwidth. Some hubs can provide multiple ports full 1.1 bandwidth, using the higher-speed USB protocol to the PC as a backhaul. There were quite a few other issues. Missing solder, cables soldered to the board directly, and no bypass capacitors. The per-port switches cut off USB power, but that...