Vantablack is a special coating material, moreso than a paint. It’s well-known as one of the blackest possible coatings around, capable of absorbing almost all visible light in its nanotube complex structure. However, it’s complicated to apply, delicate, and not readily available, especially to those in the art world.
It was these drawbacks that led Stuart Semple to create his own incredibly black paint. Over the years, he’s refined the formula and improved its performance, steadily building a greater product available to all. His latest effort is Black 4.0, and it’s promising to be the black paint to dominate all others.
The Earth’s ionosphere is the ionized upper part of the atmosphere, and it’s also the most dynamic as it swells and ebbs depending on whether it’s exposed to the Sun or not. It’s the ionosphere that enables radio frequency communications to reach beyond the horizon, its thickness and composition also affects the range and quality of these transmissions. Using this knowledge, a group of ham radio operators used the October 14 solar eclipse to crowdsource an experiment, as part of the Ham Science Citizen Investigation (HamSCI) community.
A solar eclipse is an interesting consideration with ionospheric RF transmissions, as it essentially creates a temporary period of night time, which is when the ionosphere is the least dense, and thus weakening these transmissions and their total range. As with previous solar eclipses, they turned it into a kind of game, where each ham operator attempts to contact as many others as possible within the least amount of time. Using the collected data points on who was able to talk to whom on the globe, the event’s effect on RF transmissions could be plotted over time. For the August 21, 2017 solar eclipse, the results were published in a 2018 paper by N. A. Frissell et al. in Geophysical Research Letters.
One point which they wished to examine during the 2023 solar eclipse were the plasma bubbles that form near the Earth’s magnetic equator, in regions like Brazil. These plasma bubbles cause a lot of interference, which in the preliminary data can be seen as a clear Doppler shift of the signal due to the diffusion of the ionosphere as the eclipse’s effect took hold. For the next solar eclipse in April 2024 another experiment is scheduled, which will give even more ham radio operators the chance to sign up and contribute to ionospheric science.
Top image: A schematic representation of the different ionospheric sub-layers and how they evolve daily from day to night periods. (Credit: Carlos Molina)
While it might not seem like it today, there was a time in the not-too-distant past where Motorola was the processor manufacturer. They made chips for everything, but the most popular was arguably the 68000 or 68k. It’s still has a considerable following today, largely among retrocomputing enthusiasts or those maintaining legacy hardware. For those wanting to dip their toes into this world, this Motorola 68000 emulator created by [Ted Fried] may be the thing needed to discover the magic of these once-ubiquitous chips.
The emulator itself runs on a Teensy 4.1, a 32-bit ARM microcontroller running at 600 MHz — giving it enough computing power to act as a cycle-accurate emulator not only for the 68000 CPU but also the local bus interface, in this case for a Mac 512K. This capability also makes it a drop-in replacement for the 68000 in these older Macs and the original hardware in these computers won’t notice much of a difference. A few tricks are needed to get it fully operational though, notably using a set of latches to make up for the fact that the Teensy doesn’t have the required number of output pins to interface one-to-one with the original hardware.
While the emulator may currently be able to replace the hardware and boot the computer, there is still ongoing development to get every part of the operating system up and working. The source code is available on the project’s GitHub page though so any updates made in the future can be found there. And if you have a Mac 128k and still haven’t upgraded to the 512k yet, grab one of these memory switching modules for the upgrade too.
Every hacker appreciates how off-the-shelf parts can be combined into something greater, and [bryan.lowder] demonstrates this beautifully with his organ-playing skeleton, a wonderful entry to our 2023 Halloween Contest!
Skelly the 3-foot-tall novelty skeleton animatedly plays Bach’s Toccata and Fugue in D Minor while perched at an old (and non-functional) Hammond organ. The small animatronic skeleton has canned motions that work very well for mock organ playing while an embedded MP3 player takes care of playing the music.
That’s not to say the project didn’t have its challenges. Integrating off-the-shelf components into a project always seems to bring its own little inconveniences. In this case, the skeleton the MP3 player both expect to be triggered with button pushes, but taping the button down wasn’t enough to get the skeleton moving when power was applied. [bryan] ended up using relays to simulate button pushes, and a 555 timer circuit to take care of incorporating a suitable delay.
As [bryan] puts it, “a technical tour de force it ain’t, but it is practical and it works and it was done on time” which is well said. Watch Skelly in action in the video, embedded below. There’s also a second video showing the homebrewed controller and MP3 player, both concealed under Skelly’s robe.
[Useful Sensors] aims to embed a variety of complementary AI tools into a small, private, self-contained module with no internet connection with AI in a Box. It can do live voice recognition and captioning, live translation, and natural language conversational interaction with a local large language model (LLM). Intriguingly, it’s specifically designed with features to make it hack-friendly, such as the ability to act as a voice keyboard by sending live transcribed audio as keystrokes over USB.
Based on the RockChip 3588S SoC, the unit aims to have an integrated speaker, display, and microphone.
Right now it’s wrapping up a pre-order phase, and aims to ship units around the end of January 2024. The project is based around the RockChip 3588S SoC and is open source (GitHub repository), but since it’s still in development, there’s not a whole lot visible in the repository yet. However, a key part of getting good performance is [Useful Sensors]’s own transformers library for the RockChip NPU (neural processing unit).
The ability to perform things like high quality local voice recognition and run locally-hosted LLMs like LLaMa have gotten a massive boost thanks to recent advances in machine learning, and it looks like this project aims to tie them together in a self-contained package.
Perhaps private digital assistants can become more useful when users can have the freedom to modify and integrate them as they see fit. Digital assistants hosted by the big tech companies are often frustrating, and others have observed that this is ultimately because they primarily exist to serve their makers more than they help users.
You may know William Blake as a poet, or even as #38 in the BBC’s 2002 poll of the 100 Greatest Britons. But did you know that Blake was also an artist and print maker who made illuminated (flourished) books?
Blake sought to marry his art with his poetry and unleash it on the world. To do so, he created an innovative printing process, which is recreated by [Michael Phillips] in the video after the break. Much like etching a PCB, Blake started with a copper sheet, writing and drawing his works backwards with stopping varnish, an acid-resistant varnish that sticks around after a nitric acid bath. The result was a raised design that could then be used for printing.
Cleaning up the ink smudges before printing.
Blake was a master of color, using few pigments plus linseed or nut oil to create pastes of many different hues. Rather than use a brayer, Blake dabbed ink gently around the plate, careful not to splash ink or get any in the etched-away areas. As this was bound to happen anyway, Blake would then spend more time wiping out the etched areas than he did applying the ink.
Another of Blake’s innovations was the printing process itself. Whereas traditionally, illuminated texts must be printed in two different workshops, one for the text and the other for the illustrations, Blake’s method of etching both in the same plate of copper made it possible to print using his giant handmade press.
Have you ever looked at a guitar and thought “Nah, that’s way too easy to play.”[Mattias Kranz] seems to have done, so he built the 360 Guitar, a new instrument with a circular, rotating neck. The rotating neck means that it can have more strings than most: we think that it has sixteen, but it’s hard to tell. Anyway, it has a lot of strings and looks utterly impractical, which makes it an exciting project.
The basic idea is intriguing: take a conventional guitar design and replace the fretboard with a rotating pillar. Perhaps even stick a motor in there to rotate it on command. Each of the strings is mounted along this pillar using standard string retainers and tuning pegs, with frets along the pillar. Because you can fit so many strings, you can use all of the standard strings for a bass and treble guitar, plus a few extra like the thickest bass string available and the thinnest guitar strings. It’s like a four-dimensional Chapman Stick.
[Mathias] is still working on the project as you can see in the video below the break, so we will be interested to see what new design aspects he comes up with, like the plan to use a motor to rotate the neck. [Mattias] has built a few instruments that we have featured before, like the Helium guitar, which replaces the resonant cavity with a helium balloon, and the Plasma Piano, a combination of piano and tuned plasma coil.
