Daily Archives: September 5, 2023

Paper Cups Are Bad for the Environment Too, Study Finds

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[…]

A study published last month in the journal Environmental Pollution outlines how paper cups can leach toxic materials into the surrounding environment. This is because paper cups are often coated in a layer of polylactic acid, otherwise known as PLA. It’s a bioplastic and is touted as a biodegradable alternative to traditional plastic. However, researchers found that it caused adverse health effects in aquatic midge larvae.

Researchers at the University of Gothenburg tested the effects of both plastic cups and paper cups on the midge larvae. Both types of cups were put in water or sediments for up to four weeks. The larvae were then put into aquariums that contained the sediment and water that once held the plastic and paper cups. The contaminated sediment and water were tested separately.

“We observed a significant growth inhibition with all the materials tested when the larvae were exposed in contaminated sediment,” the researchers wrote in the study. “Developmental delays were also observed for all materials, both in contaminated water and sediment.”

They found that growth challenges and developmental delays were observed in environments where the cups leached into them for only one week. The negative effects of the exposure increased in the water and sediment that held the paper and plastic cups for longer periods of time. This challenges the belief that bioplastics are safer. PLA does break down faster than traditional fossil fuel-based plastic material, but the study results show that they aren’t much safer.

“Bioplastics does not break down effectively when they end up in the environment, in water,” Bethanie Carney Almroth, a professor at the University of Gothenburg and study author, said in a press release. “There may be a risk that the plastic remains in nature and resulting microplastics can be ingested by animals and humans, just as other plastics do. Bioplastics contain at least as many chemicals as conventional plastic.”

Other previous studies have found that the plastic coating in paper cups can also create microplastics that enter the liquid in the cup. In 2019, a research group based out of India filled paper cups with hot water and found that there were an alarming amount of microplastic particles in a paper cup after filling the cups with hot liquids, Wired reported. The researchers found that there were about 25,000 particles per 100 ml cup after 15 minutes.

[…]

Source: Paper Cups Are Bad for the Environment Too, Study Finds

Watch Oscilloscope Kickstarter rewards sent – 10 years after backing

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It may have taken ten years to come through on this particular Kickstarter, but a promise is a promise. In late August 2023, backers who had since likely forgotten all about the project started receiving their oscilloscope watches from creator [Gabriel Anzziani]. Whatever the reason(s) for the delay, the watch looks great, and is miles ahead of the prototype pictures.

As you may have guessed, it functions as both a watch and an oscilloscope. The watch has 12- and 24-hour modes as well as an alarm and calendar, and the ‘scope has all the features of the Xprotolab dev board, which [Gabriel] also created: ‘scope, waveform generator, logic analyzer, protocol sniffer, and frequency counter.

Internally, it has an 8-bit Xmega microcontroller which features an internal PDI, and the display is a 1.28″ e-ink display. When we covered this ten years ago, the screen was the type of Sharp LCD featured in the Pebble watch. [Gabriel]’s ‘scope watch features eight buttons around the edge which are user-programmable. One of [Gabriel]’s goals was for people to make their own apps.

Of course, the Kickstarter rewards are no longer available, but if you want to build your own small, digital ‘scope, check out this DIY STM32 project.

Source: The ‘Scope Of This Kickstarter? Ten Years. | Hackaday

Some Galaxies Contain Double Supermassive Black Holes

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Blazars occupy an intriguing spot in the cosmic zoo. They’re bright active galactic nuclei (AGN) that blast out cosmic rays, are bright in radio emission, and sport huge jets of material traveling in our direction at nearly the speed of light. For some blazars, their jets look curvy and snaky and astronomers have questions.

[…]

“We present evidence and discuss the possibility that it is in fact the precession of the jet source, either caused by a supermassive binary black hole at the footpoint of the jet or – less likely – by a warped accretion disk around a single black hole, that is responsible for the observed variability,” said Britzen from the Max Planck Institute for Radio Astronomy in Bonn, Germany.

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Britzen and the team investigated an object called OJ 287 to see if it could give some clues. It appears to have two black holes—essentially a black hole binary—at its core. Studies of this galaxy and 12 other AGNS led to the conclusion that jet curvature may provide a smoking gun clue to the existence of binary black holes in galaxy cores.

[…]

One black hole is emitting the jet and the other one’s gravitational influence affects the appearance and behavior of the jet. According to Michal Zajacek, who is a co-author of the study with Britzen, it helps explain the jet’s appearance. “Physics of accretion disks and jets is rather complex but their bulk kinematics can be compared to simple gyroscopes,” he said. “If you exert an external torque on an accretion disk, for instance by an orbiting secondary black hole, it will precess and nutate, and along with it the jet as well, similar to the Earth’s rotation axis that is affected by the Moon and the Sun.”

 A magnetized radio jet (yellow), precessing due to a pair of supermassive black holes. The larger one is shown in black at the center of the accretion disk. It contains warmer (blue) and cooler (red) gas. The white arrow indicates the spin of the larger black hole. The second black hole orbits (orange) around the central supermassive black hole and the orange arrow shows the orientation of its orbital angular momentum. Due to misalignment, torque from the secondary drives the precession of the accretion disk as well as the launched jet (green circle and arrows).  Radio emission is indicated with white curved lines. These show how the jet swirls around and produces variations in radio emission. Courtesy: Michal Zaja?ek/UTFA MUNI
 A magnetized radio jet (yellow), precessing due to a pair of supermassive black holes. The larger one is (black) at the center of the accretion disk. It contains warmer (blue) and cooler (red) gas. The white arrow indicates the spin of the larger black hole. The second black hole orbits (orange) around the central supermassive black hole and the orange arrow shows the orientation of its orbital angular momentum. Due to misalignment, torque from the secondary drives the precession of the accretion disk as well as the launched jet (green circle and arrows).  White curved lines indicate radio emission. Courtesy: Michal Zaja?ek/UTFA MUNI

Searching for the Black Hole Binaries

If this is the case for other blazars, the meandering jet and brightness variability may well be the clue astronomers need to probe for other binary black holes. It’s not an easy task to find the black holes, even though the AGNS themselves are bright, according to Britzen. “We still lack the sufficient resolution to probe the existence of supermassive binary black holes directly,” she said. “But jet precession seems to provide the best signature of these objects, whose existence is expected not only by the black hole / AGN community but also from the gravitational wave/pulsar community who recently published evidence for the existence of a cosmic gravitational background due to the gravitational waves emitted by the mergers of massive black holes through cosmic history.”

[…]

Source: Some Galaxies Contain Double Supermassive Black Holes – Universe Today

antiX 23: Ultralightweight minimal Debian 12 desktop

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The latest release of antiX is Linux how it used to be, in the good way. It’s not the friendliest, but it does everything – and, wow, it’s fast.

The “proudly antifascist” antiX project has released its latest edition, based on Debian 12. This release is codenamed Arditi del Popolo – “the People’s Daring Ones” – after a 1920s Italian antifascist group formed to oppose Mussolini’s regime. antiX is not, as the name might imply, opposed to the X window system: its main editions are graphical, with a choice of environments (although there is a super-minimal, text-only edition if that’s what you want).

Instead, antiX seems to be opposed to pretty much all of the modern trends in desktop Linux, the sorts of technologies that old-timers often consider bloated or inefficient. It doesn’t use systemd or elogind. It doesn’t have Wayland, or heavyweight cross-distro packaging tools such as Flatpak or Snap. It doesn’t even have any of the standard desktop environments. By antiX standards, we suspect that a “desktop environment” would count as bloat.

(If you prefer a familiar desktop, then antiX 23 is one of the parent distros of MX Linux 23, which offers both Xfce and KDE variants.)

Instead of an integrated desktop, antiX provides a broad selection of tools that provide all the functionality of a desktop: app launchers, status monitors, wireless networking, file managers, whatever you need. Not only is it present, but you get a selection of alternatives, and in many cases there are both graphical and shell-based tools available. Despite all this, the 64-bit edition with kernel 6.1 still idles at under 200MB of memory in use, which is startlingly good for a 2023 distro. The Reg standard recommendation for a lightweight desktop Linux is the Raspberry Pi Desktop, which is based on Debian 11 and LXDE. antiX is built from newer components, but even so it uses less memory and it’s faster too.

So in a way, it reminds The Reg FOSS Desk of the good aspects of Linux the way it was in the 20th century. The full edition comes with lots of applications, including a few of the standard big names, such as Firefox ESR and LibreOffice. Aside from them, though, most are less well-known alternatives, ones that are smaller, faster, and take less memory.

antiX 23 with IceWM and a couple of ROX Filer windows open. Looks like a desktop, works like a desktop – but faster

antiX 23 with IceWM and a couple of ROX Filer windows open. Looks like a desktop, works like a desktop – but faster

What’s missing are the bad parts. From modern Linux, the multiple huge, lumbering tools, all too often written in relatively sluggish interpreted programming languages, each of which pulls in a gigabyte of dependencies; and worse still, allegedly “local applications” which are actually web applets implemented in Javascript, so each tool drags an entire embedded web browser around with it. And from 1990s Linux, the rough edges: this is a modern distro, with modern hardware support, and the standard installation gives you a complete graphical environment with sound, networking and so on all pre-configured and working.

It stands in contrast to most other contemporary minimal distros such as Alpine Linux, Arch Linux or Void Linux, to pick some random examples. While these are all very capable distros, you must do a substantial amount of manual installation and configuration post-installation if you want a graphical desktop and the usual assortment of text editors, media players, communications tools, and so on. They also have their own idiosyncratic packaging tools etc. so to get started with customizing your new distro, you’ll probably have to spend some time on Google finding the commands and their syntax.

antiX is based on Debian, which, as we said when celebrating its 30th birthday recently, is the most widely used family of Linux distros there is – so it uses the familiar apt commands for managing software.

antiX 23 with JWM and the zzz file manager. It's different, but not very. We're not convinced it really needs both

antiX 23 with JWM and the zzz file manager. It’s different, but not very. We’re not convinced it really needs both

So it’s a cut-down Debian “Bookworm”, with some of the controversial bits – such as systemd and the fancy desktop environments – taken out. You get a choice of two init systems: the default sysvinit or the more modern runit. These aren’t installation options, as they are in Devuan, say: you must choose and download the appropriate installation image. There are both 32-bit and 64-bit x86 editions.

The full edition offers four window managers: IceWM, JWM, Fluxbox, and Herbsluftwm. IceWM offers a fairly rich Windows-like setup, with a taskbar, start menu, and some preconfigured system monitors and applets. JWM offers a more basic, no-frills version of the same layout. Fluxbox drops all that stuff for an even more minimalistic overlapping window manager. All include the Conky desktop status display. Finally, Herbsluftwm is an extremely minimal tiling window manager.

But the choices don’t end there. antiX also includes two different file managers, ROX Filer and zzz, both of which provide desktop icons and multi-folder-window style navigation. Optionally, ROX Filer has its own desktop panel too for an approximate simulation of RISC OS desktop, which means you get two different desktop panels.

There are also “minimal” login options, which don’t load a file manager. This means the (extremely basic) slimski login screen offers no less than 13 desktop options.

This is emblematic of the main issue with antiX: if anything, it offers too much choice. There are full, light, and minimal editions; sysvinit and runit editions; and i686 and x86-64 editions. There are over a dozen different combinations of window manager and file managers. The top-level app menu has 14 entries, with both a “Control Centre” and a “Settings” submenu. One of the menu entries is called “Applications” and contains the usual hierarchical list of apps, but some are also on the top level, and there’s a “Personal” menu where you can pin your favourites. This is accessible from the Start button analog in the two window managers which have one, and by right-clicking the desktop in all three which have a desktop. For all the main app categories – text editors, and web browsers, media players, and so on – there are multiple options, sometimes three or four of them.

Considering that this is one of the most lightweight Linux distros, it’s an embarrassment of riches. There are so many options, choices, themes, and settings, most of them with multiple ways to get at them, that even for an experienced user, it’s bewildering. There are even 16 different downloads on offer: Full, Base, Core, and Net, two init systems, and two CPU architectures.

The Fluxbox window manager, with its virtual desktop switcher control at the bottom, and ROX Session's panel at the top. With some tweaking, it could be very like RISC OS

The Fluxbox window manager, with its virtual desktop switcher control at the bottom, and ROX Session’s panel at the top. With some tweaking, it could be very like RISC OS

While with Alpine or Void, you can achieve an extremely lightweight, fully graphical desktop system, you must do this by installing and configuring most of it yourself. With antiX, to get to a setup you are happy with, you will still have to do quite a lot of custom configuration, but it will be removing tools that you don’t want. Of course, there are package management tools to help you do that: there’s Package Installer, and Program Remover, and Synaptic, and a menu-driven shell-based package manager, and of course apt – and apt-get and aptitude.

When you download, install, and boot antiX, it feels amazingly tiny and fast by modern standards. We have the older release 21 on our elderly Atom-based Sony Vaio P, and it makes that geriatric sub-netbook feel sprightly. Then you log in, start to browse the application menu, and find a Swiss army knife, where there’s a tool for everything. The trouble is, each blade unfolds to reveal another Swiss army knife. It’s almost fractal.

Back when Ubuntu first launched in 2004, it scored over Debian because someone had done the curation of programs for you. You got what was arguably the best completely FOSS desktop at the time, GNOME 2, and one best-of-breed app in each category of essential program – one web browser, one email client, one media player, and so on, all nicely set up and integrated into a harmonious whole. And when it started out, it was relatively slim and lightweight and fast. With Debian, you had to choose all this for yourself, which gives you great freedom, but requires considerable expertise, and the result might not feel very coherent and require quite some fine tuning. Now, both are pretty big, and these days Ubuntu offers a choice of 10 different desktop flavors, plus Server and Core and container images and more.

This is where MX Linux scores over this, its much smaller parent distro. The MX team does that curation for you. With antiX, you get the freedom to pick and choose from a profusion of tools, many of which you’ve probably never heard of and so wouldn’t know to install. But you will probably want to break out the hammer and chisel, and sculpt it down into something you find pleasing.

It’s a very interesting distro, if you know a bit of what you’re doing and want to learn and experiment and customize it. It’s also very lightweight in resource usage, and will run well on some ancient hardware that most modern distros won’t even attempt to boot on.

But we can’t help but feel that, as its name hints, it’s a bit anarchic. It feels designed by committee, where everyone got their choices included. Some judicious pruning and selection would really help buff it to a shine.

Source: antiX 23: Ultralightweight minimal Debian 12 • The Register