Airline Seats Are For Dummies

September 18, 2024 by 10 Comments

You normally don’t think a lot would go into the construction of a chair. However, when that chair is attached to a commercial jet plane, there’s a lot of technology that goes into making sure they are safe. According to a recent BBC article, testing involves crash dummies and robot arms.

Admittedly, these are first-class and business-class seats. Robots do repetitive mundane tasks like opening and closing the tray table many, many times. They also shoot the seats with crash dummies aboard at up to 16 Gs of acceleration. Just to put  that into perspective, a jet pilot ejecting gets about the same amount of force. A MiG-35 pilot might experience 10 G.

We didn’t realize how big the airline seat industry is in Northern Ireland. Thompson, the company that has the lab in question, is only one of the companies in the country that builds seats. Apparently, the industry suffered from the global travel slowdown during the pandemic but is now bouncing back.

While people worry about robots taking jobs, we can’t imagine anyone wanting to spend all day returning their tray table to the upright and locked position repeatedly. We certainly don’t want to be 16 G crash dummies, either.

Crash dummies have a long history, of course. Be glad airliners don’t feature ejector seats.

Catching The BOAT: Gamma-Ray Bursts And The Brightest Of All Time

September 18, 2024 by 12 Comments

Down here at the bottom of our ocean of air, it’s easy to get complacent about the hazards our universe presents. We feel safe from the dangers of the vacuum of space, where radiation sizzles and rocks whizz around. In the same way that a catfish doesn’t much care what’s going on above the surface of his pond, so too are we content that our atmosphere will deflect, absorb, or incinerate just about anything that space throws our way.

Or will it? We all know that there are things out there in the solar system that are more than capable of wiping us out, and every day holds a non-zero chance that we’ll take the same ride the dinosaurs took 65 million years ago. But if that’s not enough to get you going, now we have to worry about gamma-ray bursts, searing blasts of energy crossing half the universe to arrive here and dump unimaginable amounts of energy on us, enough to not only be measurable by sensitive instruments in space but also to effect systems here on the ground, and in some cases, to physically alter our atmosphere.

Gamma-ray bursts are equal parts fascinating physics and terrifying science fiction. Here’s a look at the science behind them and the engineering that goes into detecting and studying them.

Continue reading “Catching The BOAT: Gamma-Ray Bursts And The Brightest Of All Time” →

Bringing The Horror Of Seaman Into The Real World

September 18, 2024 by 13 Comments

A little under 25 years ago, a particularly bizarre game was released for Sega’s Dreamcast. In actually, calling it a “game” might be something of a stretch. It was more of a pet simulator, where you need to feed and care for a virtual animal as it grows. Except rather than something like a dog or a rabbit, your pet is a talking fish with a human face that doesn’t seem to like you very much. Oh, and Leonard Nimoy is there too for some reason.

Most people in the world don’t even know this game ever existed, and frankly, their lives are all the better for it. But for those who lovingly cared for (or intentionally killed) one of these rude creatures back in the early 2000s, it’s an experience that sticks with you. Which we assume is why [Robert Prest] decided to build this incredibly faithful physical recreation of Seaman. 

Continue reading “Bringing The Horror Of Seaman Into The Real World” →

From High Level Language To Assembly

September 18, 2024 by 24 Comments

If you cut your teeth on Z-80 assembly and have dabbled in other assembly languages, you might not find much mystery in creating programs using the next best thing to machine code. However, if you have only used high level languages, assembly can be somewhat daunting. [Shikaan] has an introductory article aimed to get you started at the “hello world” level of x86-64 assembly language. The second part is already up, too, and covers control structures.

You can argue that you may not need to know assembly language these days, and we’ll admit it’s certainly not as important as it used to be. However, there are unusual cases where you really need either the performance or the small footprint, which is only possible in assembly language. What’s more, it is super useful to be able to read assembly from your high-level tools when something goes wrong.

Of course, one of the problems is that each assembly language is different. For example, knowing that the x86 assembly doesn’t completely transfer to ARM instructions. However, in most cases, the general concepts apply, and it is usually fairly easy to learn your second, third, or fourth instruction set.

We’ve had our own tutorials on this topic. You can also debate if you should learn assembly first or wait, although in this case, the audience is people who waited.

A Brand New USB Modem In The 2020s

September 17, 2024 by 11 Comments

The dulcet tones of a modem handshake may be a thing of the distant past for most of us, but that hasn’t stopped there being a lively hacking scene in the world of analogue telephones. Often that’s achieved using old devices resurrected from a parts bin, but sometimes, as with [Brian]’s USB modem, the devices are entirely new.

A surprise is that modem chips are still available, in this case the SkyWorks IsoModem chips. It uses an M.2 module format to allow the modem and support circuitry to be separated enough to place it in another project if necessary, along with a clear warning on the PCB not to put it in the identical-looking PC slot. It also comes with tips for experimenting if you don’t have access to a landline too, given that POTS is fast becoming a thing of the past itself in so many places.

If you’ve got nowhere to show off your modem, we’d like to suggest you try a hacker camp. There you’ll often find a copper network you’re positively expected to hack.

Thermal Runaway: Solving The Bane Of Electric Vehicles

September 17, 2024 by 86 Comments

Although battery fires in electric cars and two-wheeled vehicles are not a common phenomenon, they are notoriously hard to put out, requiring special training and equipment by firefighters. Although the full scope of the issue is part of a contentious debate, [Aarian Marshall] over at Wired recently wrote an article about how the electric car industry has a plan to make a purportedly minor issue even less of an issue. Here the questions seem to be mostly about what the true statistics are for battery fires and what can be done about the primary issue with batteries: thermal runaway.

While the Wired article references a study by a car insurance company about the incidence of car fires by fuel type (gas, hybrid, electric), its cited sources are dubious as the NTSB nor NHTSA collect statistics on these fires. The NFPA does, but this only gets you up to 2018, and they note that the data gathering here is spotty. Better data is found from European sources, which makes clear that battery electric vehicles (BEVs) catch fire less often than gasoline cars at 25 per 100,000 cars sold vs 1529/100k for ICE cars, but when BEVs do burn it’s most often (60%) from thermal runaway, which can be due to factors like a short circuit in a cell, overcharging and high ambient temperatures (including from arson or after-effects of a car crash). Continue reading “Thermal Runaway: Solving The Bane Of Electric Vehicles” →

Ferrites Versus Ethernet In The Ham Shack

September 17, 2024 by 33 Comments

For as useful as computers are in the modern ham shack, they also tend to be a strong source of unwanted radio frequency interference. Common wisdom says applying a few ferrite beads to things like Ethernet cables will help, but does that really work?

It surely appears to, for the most part at least, according to experiments done by [Ham Radio DX]. With a particular interest in lowering the noise floor for operations in the 2-meter band, his test setup consisted of a NanoVNA and a simple chunk of wire standing in for the twisted-pair conductors inside an Ethernet cable. The NanoVNA was set to sweep across the entire HF band and up into the VHF; various styles of ferrite were then added to the conductor and the frequency response observed. Simply clamping a single ferrite on the wire helped a little, with marginal improvement seen by adding one or two more ferrites. A much more dramatic improvement was seen by looping the conductor back through the ferrite for an additional turn, with diminishing returns at higher frequencies as more turns were added. The best performance seemed to come from two ferrites with two turns each, which gave 17 dB of suppression across the tested bandwidth.

The question then becomes: How do the ferrites affect Ethernet performance? [Ham Radio DX] tested that too, and it looks like good news there. Using a 30-meter-long Cat 5 cable and testing file transfer speed with iPerf, he found no measurable effect on throughput no matter what ferrites he added to the cable. In fact, some ferrites actually seemed to boost the file transfer speed slightly.

Ferrite beads for RFI suppression are nothing new, of course, but it’s nice to see a real-world test that tells you both how and where to apply them. The fact that you won’t be borking your connection is nice to know, too. Then again, maybe it’s not your Ethernet that’s causing the problem, in which case maybe you’ll need a little help from a thunderstorm to track down the issue. Continue reading “Ferrites Versus Ethernet In The Ham Shack” →