As easy as the Sun is to observe, it’s simultaneously very hard to study due to how extreme the conditions are, even on the surface of a rather unassuming star. One of these study topics is the interaction between the Sun’s plasma and magnetic field, as this drives much of the dynamism of the Sun’s surface layer (i.e., the photosphere). Recent observations by the 4-meter solar telescope in Hawaii have now led to interesting new findings, as detailed in a paper in Nature by [David Kuridze] et al.

Despite popular portrayal, this photosphere is not a boiling liquid, but rather pockets of plasma at various temperatures. The plasma moves within the magnetic field and convective movements that create the ‘boiling’ pattern, which gives the illusion of a boiling liquid surface.

Within this photosphere, [Kuridze] et al. were able to observe Kelvin-Helmholtz instabilities, which are fluid instabilities caused by velocity shearing in either a continuous fluid or due to a velocity difference between two fluids. This is also observed in clouds in Earth’s atmosphere, where they cause the billowing effect, somewhat similar to watching a boiling liquid.

In a MURaM simulation (see heading image), these findings were confirmed, showing how these instabilities drive the transport of plasma in the Sun’s photosphere.

Word processors and editors are a funny thing. It doesn’t really matter what’s “best,” whatever that means. If you have finger memory built up for one program, it’s painful to change. That’s why most of us don’t learn how to type on a Dvorak keyboard and why [George R. R. Martin] writes with WordStar. Many people of a certain age have a deep memory of WordStar. Now you can run it on a modern machine or even in your browser without a lot of trouble, thanks to [nampara-ai].

The idea is simple. Take a vintage copy of WordStar for MSDOS, wrap it with DOSBox, and package it up with some basic scripts for Linux, Mac, or Windows. In addition, there’s a WebAssembly version for the browser if you’re into that sort of thing.

On Linux, the wordstar.sh file grabs the current directory and sends it to launch.sh. This script makes sure everything is ready, builds a DOSBox config file from a template, and launches everything. The only problem is that it doesn’t correctly resolve symlinks if you want a link on your path. Luckily, that’s easy to fix:

#!/usr/bin/env bash
 # Run me to launch WordStar 4.0 on Linux:  ./wordstar.sh
DIR="$(realpath "$0")"
DIR="$(dirname $DIR)"
cd "$DIR"
DIR="$(pwd)"

#DIR="$(cd "$(realpath "$(dirname "$0"))" && pwd)"
"$DIR/native/lib/launch.sh"

Practical? No. Irreplaceable? Not really. You could run WordStar under RunCPM or set up DOSBox yourself. You can even find a sort of modern version to run, if you prefer. But for just a quick way to get it running easily, it is hard to beat. If you want to play with the web version, it is easy to navigate to the web subdirectory and run Python:

python3 -m http.server 5309

Then you can point your browser to http://localhost:5309, and you are in business. Or, get a flavor for it from [TigerClawTV]’s walk-through video below.