ARCTURUS was a research computer system developed on a shoestring budget at Sydney University in the 1960s, and was in service until 1975. Particularly the system was developed by [David Wong] as a part of his PhD thesis: The design and construction of the digital computers snocom, nimbus and arcturus (PDF). [David] worked in collaboration with [Kevin R. Rosolen] who is interviewed in the video.
It turns out, that mold is everywhere. The problem is when it becomes too much, as mold infestations can have serious health effects on both humans and animals. Remediation is extremely expensive, too. So there are plenty of benefits to finding mold early. Now, German researchers are proposing an electronic “nose” that uses UV-activated tin oxide nanowires that change resistance in the presence of certain chemicals, and they say it can detect two common indoor mold species.
The nanowire sensors can detect Staachybotrys chartarum and Chaetominumglobosum. The real work, though, is in the math used to determine positive versus negative results.
You’ve heard of wind tunnels– get some airflow going over a thingy, put some some smoke on, and voila! Flow visualization. How hard could it be? Well, as always, the devil is in the details and [toast] is down in there with him with this Hot-Wheels sized wind tunnel video.
To get good, laminar flow inside of a wind tunnel, there are important ratios to be followed– the inlet and outlet diameters must relate to the interior size to get the correct slope on the contraction and exhaust cones. You need a flow straightener on both ends. All of it can be easily 3D printed, as [toast] shows, but you have to know those design rules and pay attention to, which [toast] does… this time. One of his “don’t do this” examples in this video is previous build of his where he did not follow all the rules, and the difference is clear.
Now, unless you’re hooked on flow visualizations —guilty— or are a Hot-Wheels aficionado, since that’s what this wind tunnel is sized for, you probably won’t rush to gumroad to buy [toast]’s STLs. On the other hand, if you pay attention to the lessons [toast] has learned in this video you can apply them to wind tunnels of whatever size and construction technique you need, be it cardboard or junk box plastic and get a more stable result.
Over the decades the number of Linux distributions has effectively exploded, from a handful in the late ’90s to quite literally hundreds today, not counting minor variations. There lately seems to be a counter-movement brewing in response to this fragmentation, with Project Bluefin’s Distroless project being the latest addition here. Also notable are KDE’s efforts, with KDE Linux as its own top-down KDE-based distro, but now with a switch to BuildStream from Arch likely as a distroless move.
It should be clear that there is no obvious course here yet, and that opinions are very much divided. The idea of ‘Linux’ becoming a more singular OS appeals to some, while to others it’s the antithesis of what ‘Linux’ is about. This much becomes clear in [Brodie Robertson]’s exploration of this topic as well.
The way to think about ‘distroless’ is that there is a common base using the Freedesktop SDK on which the customization layer is applied, such as Bluefin, KDE or Gnome’s environments. You could think of this base as the common runtime, using the Freedesktop standards for interoperability for a user-selected layer that’s installed on top. This way the idea of basing a distro on a specific distro is tossed out in favor of something that’s vaguely reminiscent of the Linux Standard Base attempt at standardization.
We suspect there are three kinds of people in the world. People who have access to a Michelson Interferometer and are glad, those who don’t have one and don’t know what one is, and a very small number of people who want one but don’t have one. But since [Longest Path Search] built one using 3D printing, maybe the third group will dwindle down to nothing.
If you are in the second camp, a Michelson interferometer is a device for measuring very small changes in the length of optical paths (oversimplifying, a distance). It does this by splitting a laser into two parts. One part reflects off a mirror at a fixed distance from the splitter. The other reflects off another, often movable, mirror. The beam splitter also recombines the two beams when they reflect back, producing an interference pattern that varies with differences in the path length between the splitter and the mirror. For example, if the air between the splitter and one mirror changes temperature, the change in the refraction index will cause a minute difference in the beam, which will show up using this instrument.
The device has been used to detect gravitational waves, study the sun and the upper atmosphere, and also helped disprove the theory that light is transmitted through a medium known as luminiferous aether.
All right, I’ll cut to the chase: Cheap03xD is mainly so cheap because the PCB falls within a 10 x 10 cm footprint. The point was to make a very affordable keyboard — all the parts come to ~40 Euro (~$47). So it would seem that [Lander03xD_] succeeded.
Image by [Lander03xD_] via redditCheap03xD is all the things — 36-key, split, column-staggered, wireless, hot-swappable, and uses ZMK. The batteries are easily replaceable, and no they don’t get in the way.
Those are MMD Princess silent switches, which I wouldn’t choose, but [Lander03xD_] is taking this board to the office, so I get it. They sure are a nice shade of pink, anyway, and they go really well with the pastels of the DSA keycaps and the bezel.
One cool thing to note is that the PCBs are reversible, like the ErgoDox. This isn’t [Lander03xD_]’s first board, and it won’t be the last.
Now, let’s talk batteries. [Saixos] pointed out that the design doesn’t appear to include a protection circuit. In case you can’t tell from where you’re sitting, those are nice!nano clones that [Lander03xD_] is using, and they expect a protection circuit.
[Lander03xD_] is going to look through the docs and see what’s what. The goal is not to have any daughter boards, so this may take some rethinking.
One of the most widely recognised product brands in the world is probably Coca-Cola, and its formula is famously kept a secret through precautions that probably rival those of many nation states. There are other colas, and there are many amateurs who have tried to copy Coke’s flavour, but in well over a century, nobody has managed it. Why does [LabCoatz] think his attempt will be successful where others failed? He has friends with their own mass spectrometers.
