Hackaday Links: June 29, 2025

In today’s episode of “AI Is Why We Can’t Have Nice Things,” we feature the Hertz Corporation and its new AI-powered rental car damage scanners. Gone are the days when an overworked human in a snappy windbreaker would give your rental return a once-over with the old Mark Ones to make sure you hadn’t messed the car up too badly. Instead, Hertz is fielding up to 100 of these “MRI scanners for cars.” The “damage discovery tool” uses cameras to capture images of the car and compares them to a model that’s apparently been trained on nothing but showroom cars. Redditors who’ve had the displeasure of being subjected to this thing report being charged egregiously high damage fees for non-existent damage. To add insult to injury, if renters want to appeal those charges, they have to argue with a chatbot first, one that offers no path to speaking with a human. While this is likely to be quite a tidy profit center for Hertz, their customers still have a vote here, and backlash will likely lead the company to adjust the model to be a bit more lenient, if not outright scrapping the system.
Have you ever picked up a flashlight and tried to shine it through your hand? You probably have; it’s just a thing you do, like the “double tap” every time you pick up a power drill. We’ve yet to find a flashlight bright enough to sufficiently outline the bones in our palm, although we’ve had some luck looking through the flesh of our fingers. While that’s pretty cool, it’s quite a bit different from shining a light directly through a human head, which was recently accomplished for the first time at the University of Glasgow. The researchers blasted a powerful pulsed laser against the skull of a volunteer with “fair skin and no hair” and managed to pick up a few photons on the other side, despite an attenuation factor of about 1018. We haven’t read the paper yet, so it’s unclear if the researchers controlled for the possibility of the flesh on the volunteer’s skull acting like a light pipe and conducting the light around the skull rather than through it, but if the laser did indeed penetrate the skull and everything within it, it’s pretty cool. Why would you do this, especially when we already have powerful light sources that can easily penetrate the skull and create exquisitely detailed images of the internal structures? Why the hell wouldn’t you?!
TIG welding aluminum is a tough process to master, and just getting to the point where you’ve got a weld you’re not too embarrassed of would be so much easier if you could just watch someone who knows what they’re doing. That’s a tall order, though, as the work area is literally a tiny pool of molten metal no more than a centimeter in diameter that’s bathed in an ultra-bright arc that’s throwing off cornea-destroying UV light. Luckily, Aaron over at 6061.com on YouTube has a fantastic new video featuring up-close and personal shots of him welding up some aluminum coupons. He captured them with a Helios high-speed welding camera, and the detail is fantastic. You can watch the weld pool forming and see the cleaning action of the AC waveform clearly. The shots make it clear exactly where and when you should dip your filler rod into the pool, the effect of moving the torch smoothly and evenly, and how contaminants can find their way into your welds. The shots make it clear what a dynamic environment the weld pool is, and why it’s so hard to control.
And finally, the title may be provocative, but “The Sensual Wrench” is a must-see video for anyone even remotely interested in tools. It’s from the New Mind channel on YouTube, and it covers the complete history of wrenches. Our biggest surprise was learning how relatively recent an invention the wrench is; it didn’t really make an appearance in anything like its modern form until the 1800s. The video covers everything from the first adjustable wrenches, including the classic “monkey” and “Crescent” patterns, through socket wrenches with all their various elaborations, right through to impact wrenches. Check it out and get you ugga-dugga on.