It’s a simple fact of life that everyone loves the azimuthal equidistant projection, which shows the world at the correct distance and direction from its central point, even those who have never seen the term in their life.

For example, when centred on Sydney:

One particular point of interest is that Cuba is shown east of Sydney, despite being in opposite hemispheres. And while this is literally true…

It doesn’t do much to affirm ill-conceived views of the world perpetuated by cylindrical and pseudocylindrical maps. Wouldn’t it be nice to use terrible metrics for ‘distance’ and ‘direction …

Last year I said, “Last year was nice and all, but […] if part of the goal is to practise then next time I should do something more in line with my typical approach.” The same held true this year, so this time I went for full colour and abandoned any remaining semblance of ‘Inktober’ beyond lifting the prompts. Except I didn’t really have time for daily drawings and haven’t generally enjoyed the experience of finding something for prompts that don’t inspire, so this time I decided from the outset that if I didn’t have time or …

Everyone loves the azimuthal equidistant projection; some just don’t yet realise it. For that latter camp, a quick refresher: azimuthal equidistant maps show all courses from the centre point at the appropriate angle and with correct scale – a ray from the centre to any point shows the initial bearing and length of the direct route to that point. The azimuthal equidistant projection, which unfortunately lacks a more concise name (‘Postel’?), is quite popular with some rather diverse groups, including the contemporary ‘zero-Gaussian-curvature Earth’[1] crowd. Perhaps more perplexing than this movement’s modern resurgence, is their insistance on the …

One of the labours of Hercules was surely to find a map of Earth’s magnetic field.

There’s no shortage of crude diagrams of bar magnets superimposed over cartoon globes, and plentiful plots of isogonic lines to be procured from multiple perspectives; yet for accurate depictions of the simple lines of magnetism over Earth’s surface, the offerings seem sorely slack. So just imagine how hard that would have been two thousand years before the internet.

The most common chart I see that has an actual connection to reality, is a map of isogonic lines – contours of equal magnetic …

There’s a bit of a persistent rumour getting around on internet and extranet circles. Actually far too many, but today’s lucky topic is the notion that plants produce oxygen from carbon dioxide.

It’s a simple enough story. We know that photosynthesis consumes carbon dioxide, and produces surplus oxygen. Since CO₂ quite obviously contains O₂, well, there’s not even anything to question.

Except that photosynthesis has a few more aspects than just these two gases, and the whole system isn’t an atomic process.[1] Fortunately you don’t need to be within arm’s reach of …

Let’s suppose you have a box. Ideally this is no mere supposition but you actually have a box nearby right now. If you don’t, you’ve surely had one at some point, so in that case we’ll talk about that box.

Boxes are made for storing things. You can put all sorts of things inside your box. You could even put another box inside it.

And you needn’t stop there. Another box can go inside your boxed box, or you could even put multiple boxes alongside each other inside the original box. All manner of boxes …

27 May marked a momentous Monday for people who ascribe significance to the interval between 22 December and 19 January everywhere, as it was on this day that Capricorn left Capricorn.[1]

“What?”

For those suitably stocked up on the applicable jargon, it was on this date that the point on the ecliptic with right ascension 20h referenced to B1875, and demarcating the western edge of Capricornus, now has an ecliptic longitude greater than 300°. Armed with this knowledge, you can go do something else now.

“Huh?”

Okay, so we need to step back a bit. Then step back another …

In the last few years I’ve moved more and more towards theming my general online presence around horseshoe crabs. There’s a general reason for that, and to properly honour horseshoe crabs for what they are, it deserves to be explained.

First, we have to start at the beginning. Or, the best we lesser specimens can know of the beginning. Back around the late Ordovician, at least 445 million years ago[1], there was a chelicerate currently called Lunataspis, which looked something like this:

Fast forward 445 …