The Walls Don’t Have Ears, But Fiber Optic Does

May 11, 2026 by Al Williams 8 Comments

You normally think of fiber optic as something used in network cables. However, scientists employ dedicated fibers to detect earthquakes. In simple terms, they fire a laser down the fiber and watch reflections caused by imperfections. When vibrations hit the cable, it changes the defects, which show up in the return pattern. However, with the right techniques, those vibrations could just as easily be from people speaking near the cable.

If you are alarmed, there’s good news and bad news. The good news is that the technique seems to be limited to coils of fiber that are not buried, and you have to be within about 5 meters of the fiber. The bad news is that there is plenty of dark cable all over the place. Besides, if researchers can do this successfully, you would imagine three-letter agencies around the world could do it even better.

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Honda Wants To Complicate Your E-Motorcycle

May 11, 2026 by Al Williams 51 Comments

If you ride a motorcycle, you know it is a bit of an art to manage the transmission on a typical bike. Electric motorcycles lose some of that. You usually just have a throttle and a brake. No transmission and, crucially, no clutch. Honda just patented a simulated clutch for those who want the old-school experience, according to [Ben Purvis], writing for Australian Motorcycle News.

This isn’t just a do-nothing lever on the handlebar. There’s haptic feedback to feel when the clutch engages. The motor responds to your actions on the lever. If you pull the clutch in part of the way, the motor loses power up to the point where there is no engine power with the clutch fully in.

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It’s A Water Clock, Jim, But Not As We Know It — It Has Digits

May 11, 2026 by Tyler August 12 Comments

Guess what time it is– that’s right, clock time! It’s always clock time, and when it’s clock time at Hackaday the weirder the better. So, how about a water clock that’s not actually a water clock? The water here has nothing to do with timekeeping, but is what’s driving the display. Fair to say that [Strange Inventions] is living up to the name of his YouTube channel.

You can get the idea from the header image: each digit is formed by a fifteen-segment display made up of glass bottles. A stepper-driven peristaltic pump and some membrane-pump boosters fills the bottles as needed with dyed water, while emptying is accomplished simply by having a servo dump the water into a trough. It’s an interesting, albeit messy, way to generate a display.

It wasn’t the original idea– well, the bottles were the original concept, but flipping them was not. Dumping the bottles has the advantage of not needing oodles of pumps or taking five minutes to sequentially fill and drain the bottles at each digit. The linkage to get the servo to flip all nine bottles in one go took some troubleshooting– we can relate, since the physical half of such projects usually is the hard part– but after many modifications the 3D printed mechanism worked, and we think the results are worth it.

If you’re looking for the other kind of water clock, we featured one of those before, too. This one is also of ancient style, but makes use of modern electronics. It occurs to us that if one was really, really ambitious, they could expand this [Strange] project into a very damp flip-dot style display. Continue reading “It’s A Water Clock, Jim, But Not As We Know It — It Has Digits” →

This Credit Card Computer Follows All Dimensions

May 11, 2026 by Jenny List 8 Comments

A computer the size of a credit card is nothing new. There have been many single-board computers following the familiar dimensions. [Krauseler]’s credit card computer is different, though. It packs an ESP32-C3, e-paper display, NFC reader, and, incredibly, a Li-Po battery into a credit card form factor in three dimensions rather than two. That’s right, this computer is only 1mm thick.

To ensure perfect compliance with the form factor, the enclosure, if that’s what it can be called, is a real NFC card with the middle cut out to take the electronics. The PCB is flexible, and the battery is the thinnest available. The e-paper display is an ultra-thin, flexible variant. A display connector would have been too thick, so a very fine wire-and-solder job was required.

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Want Driving Simulator Feedback? Make The Robot Do It

May 11, 2026 by Donald Papp 27 Comments

Humanoid robots are a thing now, and here’s an interesting research project that explores using one as a form of haptic media. Specifically, using a humanoid robot to move a chair while one plays a VR driving simulator.

Here’s how it works: a Unitree G1 robot sits behind a player’s chair and grasps it with its hands. Spherical markers on the chair help the robot’s depth camera know the chair’s position, and real-time G-force signals fed from the simulator (Assetto Corsa, running on PC) tell the robot how much and in what direction to shift the chair to match in-simulator events.

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The Vacuum Tube’s Last Stand(s)

May 11, 2026 by Al Williams 76 Comments

When most people think about vacuum tubes, they picture big glass bottles glowing inside antique radios or early computers. History often treats tubes as a dead-end technology that was suddenly swept away by the transistor in the 1950s. But the reality is much more interesting. Vacuum tube technology did not simply stop evolving when the transistor appeared. In fact, some of the most sophisticated and technically impressive tube designs emerged after the transistor had already been invented.

During the final decades of mainstream tube development, manufacturers pushed the technology in remarkable directions. Tubes became smaller, faster, quieter, more rugged, and more specialized. Designers experimented with exotic geometries, ceramic construction, metal envelopes, ultra-high-frequency operation, and even hybrid tube-semiconductor systems. Devices such as acorn tubes, lighthouse tubes, compactrons, and nuvistors represented a last gasp of thermionic electronics.

Ironically, many of these innovations arrived just as solid-state electronics were becoming commercially practical. Vacuum tubes were improving rapidly right up until the market abandoned them.

The Pressure to Improve

By the 1930s and 1940s, vacuum tubes dominated electronics. Radios, radar systems, military communications, industrial controls, and the first digital computers all depended on them. But everyone was painfully aware of their problems.

Traditional tubes were fragile, generated heat, consumed significant power, and suffered from limitations at high frequencies. Internal lead lengths created parasitic inductance and capacitance. At radio frequencies and especially microwave frequencies, those unwanted effects made design difficult.

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Making Big Dry Ice Blocks With Low Pressure CO2

May 11, 2026 by Maya Posch 9 Comments

Although the term ‘dry ice’ is generally used for solid CO₂, it’s much more accurate to call this ‘dry snow’, as, rather than being actual solid blocks, they are effectively snow that’s been compressed really tightly. While not really necessary for most applications of dry ice, it is possible to make blocks of actual CO₂ ice, and thus [Hyperspace Pirate], as someone with a healthy obsession with cold things had to make some of his own.