Weird Substances: Hagfish Slime

In the cold, dark recesses of ocean floors around the world, hagfish slither around like sea snakes, searching for food. When a hagfish finds a suitable carcass, it devours the dead fish in two different ways. As it burrows face-first through the tissue, eating with its jaw-less, tentacled mouth, the hagfish also absorbs nutrients through its skin.

Hagfish are not the unholy result of dumping toxic waste in the ocean. They’re one of the oldest creatures on Earth, having been around for more than 300 million years. How have they lasted this long?

A coiled hagfish reveals its slime ports. Image via Oregon Coast Aquarium

These ancient creatures have no eyes, no backbones, and no scales. They are often misidentified as eel, and often called ‘slime eels’, but they are definitely fish. They just don’t look like conventional fish. In fact, when conventional, gill-faced fish come after hagfish, those guys are in for a surprise, because hagfish have a disgusting but ingenious defense mechanism.

Whenever hagfish are attacked or even just stressed by nearby fish or curious grabby humans, they immediately emit amazing amounts of mucus at an alarming rate. At the same time, the hagfish shoots out silky strands of protein that hold the slime together in a cohesive blob. Any predator that tries to bite down on one of these velvety frankfurters of the deep sea will find its mouth and gills covered in a wad of suffocating slime.

How is it that hagfish haven’t slimed themselves out of existence? Whenever they get get a taste of their own medicine, these boneless noodles quickly twist themselves into a pretzel. In the same motion, they use their paddle-shaped tails to squeegee off the slime.

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Open-Source Satellite Propulsion Hack Chat

Join us on Wednesday, December 11 at noon Pacific for the Open-Source Satellite Propulsion Hack Chat with Michael Bretti!

When you look back on the development history of any technology, it’s clear that the successful products eventually reach an inflection point, the boundary between when it was a niche product and when it seems everyone has one. Take 3D-printers, for instance; for years you needed to build one if you wanted one, but now you can buy them in the grocery store.

It seems like we might be getting closer to the day when satellites reach a similar inflection point. What was once the province of nations with deep pockets and military muscles to flex has become far more approachable to those of more modest means. While launching satellites is still prohibitive and will probably remain so for years to come,  building them has come way, way down the curve lately, such that amateur radio operators have constellations of satellites at their disposal, small companies are looking seriously at what satellites can offer, and even STEM programs are starting to get students involved in satellite engineering.

Michael Bretti is on the leading edge of the trend toward making satellites more DIY friendly. He formed Applied Ion Systems to address one of the main problems nano-satellites face: propulsion. He is currently working on a range of open-source plasma thrusters for PocketQube satellites, a format that’s an eighth the size of the popular CubeSat format. His solid-fuel electric thrusters are intended to help these diminutive satellites keep station and stay in orbit longer than their propulsion-less cousins. And if all goes well, someday you’ll be able to buy them off-the-shelf.

Join us for the Hack Chat as Michael discusses the design of plasma thrusters, the details of his latest testing, and the challenges of creating something that needs to work in space.

join-hack-chatOur Hack Chats are live community events in the Hackaday.io Hack Chat group messaging. This week we’ll be sitting down on Wednesday, December 11 at 12:00 PM Pacific time. If time zones have got you down, we have a handy time zone converter.

Click that speech bubble to the right, and you’ll be taken directly to the Hack Chat group on Hackaday.io. You don’t have to wait until Wednesday; join whenever you want and you can see what the community is talking about.

Teardown: 168-in-1 Retro Handheld Game

The holidays are upon us, and that can mean many furrowed brows trying to figure out what token gift they can give out this year as stocking-stuffers. Something that’s a bit more interesting than a coupon book or a lotto scratcher, but also affordable enough that you can buy a few of them without having to take part in that other great holiday tradition: unnecessary credit debit.

Includes the NES classic Super Militarized Police Bros 3

Which is how I came to possess, at least temporarily, one of these cheap handheld multi-games that are all over Amazon and eBay. The one I ordered carries the brand name Weikin, but there are dozens of identical systems available, all being sold at around the same $20 USD price point. With the outward appearance of a squat Game Boy, these systems promise to provide precisely 168 games for your mobile enjoyment, and many even include a composite video out cable and external controller for the less ambulatory classic game aficionado.

At a glance, the average Hackaday reader will probably see right through this ploy. Invariably, these devices will be using some “NES on a Chip” solution to emulate a handful of legitimate classics mixed in with enough lazy ROM hacked versions of games you almost remember to hit that oddly specific number of 168 titles. It’s nearly a foregone conclusion that at the heart of this little bundle of faux-retro gaming lies a black epoxy blob, the bane of hardware tinkerers everywhere.

Of course, there’s only one way to find out. Let’s crack open one of these budget handhelds to see what cost reduction secrets are inside. Have the designers secured their place on the Nice List? Or have we been sold the proverbial lump of coal?

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Hackaday Links: December 8, 2019

Now that November of 2019 has passed, it’s a shame that some of the predictions made in Blade Runner for this future haven’t yet come true. Oh sure, 109 million people living in Los Angeles would be fun and all, but until we get our flying cars, we’ll just have to console ourselves with the ability to “Enhance!” photographs. While the new service, AI Image Enlarger, can’t tease out three-dimensional information, the app is intended to sharpen enlargements of low-resolution images, improving the focus and bringing up details in the darker parts of the image. The marketing material claims that the app uses machine learning, and is looking for volunteers to upload high-resolution images to improve its training set.

We’ve been on a bit of a nano-satellite bender around here lately, with last week’s Hack Chat discussing simulators for CubeSats, and next week’s focusing on open-source thrusters for PocketQube satellites. So we appreciated the timing of a video announcing the launch of the first public LoRa relay satellite. The PocketCube-format satellite, dubbed FossaSat-1, went for a ride to space along with six other small payloads on a Rocket Lab Electron rocket launched from New Zealand. Andreas Spiess has a short video preview of the FossaSat-1 mission, which was designed to test the capabilities of a space-based IoT link that almost anyone can access with cheap and readily available parts; a ground station should only cost a couple of bucks, but you will need an amateur radio license to uplink.

We know GitHub has become the de facto standard for source control and has morphed into a collaboration and project management platform used by everybody who’s anybody in the hacking community. But have you ever wished for a collaboration platform that was a little more in tune with the needs of hardware designers? Then InventHub might be of interest to you. Currently in a limited beta – we tried to sign up for the early access program but seem to have been put on a waiting list – it seems like this will be a platform that brings versioning directly to the ECAD package of your choice. Through plugins to KiCad, Eagle, and all the major ECAD players you’ll be able to collaborate with other designers and see their changes marked up on the schematic — sort of a visual diff. It seems interesting, and we’ll be keeping an eye on developments.

Amazon is now offering a stripped-down version of their Echo smart speaker called Input, which teams up with speakers that you already own to satisfy all your privacy invasion needs on the super cheap — only $10. At that price, it’s hard to resist buying one just to pop it open, which is what Brian Dorey did with his. The teardown is pretty standard, and the innards are pretty much what you’d expect from a modern piece of surveillance apparatus, but the neat trick here involved the flash memory chip on the main board. Brian accidentally overheated it while trying to free up the metal shield over it, and the BGA chip came loose. So naturally, he looked up the pinout and soldered it to a micro-SD card adapter with fine magnet wire. He was able to slip it into a USB SD card reader and see the whole file system for the Input. It was a nice hack, and a good teardown.

Hackaday Podcast 045: Raspberry Pi Bug, Rapidly Aging Vodka, Raining On The Cloud, And This Wasn’t A Supercon Episode

Hackaday editors Mike Szczys and Elliot Williams talk over the last three weeks full of hacks. Our first “back to normal” podcast after Supercon turns out to still have a lot of Supercon references in it. We discuss Raspberry Pi 4’s HDMI interfering with its WiFi, learn the differences between CoreXY/Delta/Cartesian printers, sip on Whiskey aged in an ultrasonic jewelry cleaner, and set up cloud printing that’s already scheduled for the chopping block. Along the way, you’ll hear hints of what happened at Supercon, from the definitive guide to designing LEDs for iron-clad performance to the projects people hauled along with them.

Take a look at the links below if you want to follow along, and as always tell us what you think about this episode in the comments!

Take a look at the links below if you want to follow along, and as always, tell us what you think about this episode in the comments!

Direct download (60 MB or so.)

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This Week In Security: Tegra Bootjacking, Leaking SSH, And StrandHogg

CVE-2019-5700 is a vulnerability in the Nvidia Tegra bootloader, discovered by [Ryan Grachek], and breaking first here at Hackaday. To understand the vulnerability, one first has to understand a bit about the Tegra boot process. When the device is powered on, a irom firmware loads the next stage of the boot process from the device’s flash memory, and validates the signature on that binary. As an aside, we’ve covered a similar vulnerability in that irom code called selfblow.

On Tegra T4 devices, irom loads a single bootloader.bin, which in turn boots the system image. The K1 boot stack uses an additional bootloader stage, nvtboot, which loads the secure OS kernel before handing control to bootloader.bin. Later devices add additional stages, but that isn’t important for understanding this. The vulnerability uses an Android boot image, and the magic happens in the header. Part of this boot image is an optional second stage bootloader, which is very rarely used in practice. The header of this boot image specifies the size in bytes of each element, as well as what memory location to load that element to. What [Ryan] realized is that while it’s usually ignored, the information about the second stage bootloader is honored by the official Nvidia bootloader.bin, but neither the size nor memory location are sanity checked. The images are copied to their final position before the cryptographic verification happens. As a result, an Android image can overwrite the running bootloader code. Continue reading “This Week In Security: Tegra Bootjacking, Leaking SSH, And StrandHogg”

Retrotechtacular: The Gyro-X

In the 1950s, American automobiles bloomed into curvaceous gas-guzzlers that congested the roads. The profiles coming out of Detroit began to deflate in the 1960s, but many bloat boats were still sailing the streets. For all their hulking mass, these cars really weren’t all that stable — they still had issues with sliding and skidding.

One man sought to fix all of this by re-imagining the automobile as a sleek torpedo that would scream down the road and fly around turns. This man, Alex Tremulis, envisioned the future of the automobile as a two-wheeled, streamlined machine, stabilized by a gyroscope. He called it the Gyro-X.

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