diagrams – Miscellaneous Details

Lucy in the sky with asteroids

Well done to the data team at The Economist, having to visualise a 12-year journey of a space probe as it makes a flying visit to eight different asteroids. They’ve made a very complicated journey look quite straightforward and elegant.

A probe intended to study the Trojan asteroids takes off – The Economist
Lucy, as this planetary-ancestor-investigating mission is dubbed, after a well-known specimen of Australopithecus, an early hominid, blasted off from Cape Canaveral, in Florida, and will now follow one of the most complex paths around the solar system yet devised by NASA’s orbital navigators. The diagram which shows Lucy’s journey, indicates how the craft will first pick up speed using two velocity-boosting fly-bys of Earth. It will then head for the Greek camp, passing, for a practice run at observation, by way of a convenient main-belt asteroid that the mission’s scientists have named Donaldjohanson, in honour of the discoverer of Lucy the Australopithecine. When it arrives at L4 in 2027, it will encounter five bodies: Eurybates and its tiny satellite Queta, Polymele, Leucus and Orus. Having examined each of these, it will leave the Greek camp in 2028 and cross, via another velocity-boosting fly-by of Earth, to the Trojan camp at L5. Its final planned encounter, when it reaches L5 in 2033, is with Patroclus and Menoetius.

Fortunately, they were able to call on the team at NASA’s Scientific Visualisation Studio for help.

Lucy mission trajectory – NASA Scientific Visualization Studio
Lucy will launch in October 2021 and, with boosts from Earth’s gravity, will complete a twelve-year journey to eight different asteroids — a Main Belt asteroid and seven Jupiter Trojans, the last two members of a “two-for-the-price-of-one” binary system. Lucy’s complex path will take it to both clusters of Trojans and give us our first close-up view of all three major types of bodies in the swarms (so-called C-, P- and D-types).

Getting stuck and unstuck

Do you ever get stuck with your blog? I certainly do, as these gaps between posts can testify. Here, Tim Davies shares his obstacles and succinctly reminds us why he — and many of the rest of us — sticks with it.

Overcoming posting-paralysis? – Tim’s Blog
The caption of David Eaves’ blog comes to mind: “if writing is a muscle, this is my gym”. And linked: writing is a tool of thought. So, if I want to think properly about the things I’m reading and engaging with, I need to be writing about them. And writing a blog post, or constructing a tweet thread, can be a very effective way to push that writing (and thinking) beyond rough bullet points, to more complete thoughts.

And for inspiration, check out these visualisations of creative processes.

Process – Melike Turgut
No matter how much we all try to ground our ideas in simplicity, the process of solving a creative problem is often chaotic. With this project, I try to make sense of the chaos by trying to pin-point the stages of my creative process. I use time as my constant [represented as a straight red line] and map my process around it.

Visualising change

Who knows how all this will end, it’s all guesswork. Will the final figures for the UK be between 7,000 and 20,000? Perhaps as high as 66,000? Depends on your model. Can we at least say for certain that this will end at some point? Are things already slowing down?

Three graphs that show a global slowdown in COVID-19 deaths – The Conversation
Other published graphs have shown the number of deaths reported each day for various countries. These are more useful, but the reader is still left trying to discern the extent to which the rise from one day to the next is larger or smaller. The graph below is different. It shows both the number of deaths each day and the rate of change in that number. Most importantly, it uses smoothed data – a moving average from the day before to the day after each date shown.

OK. I think I follow that.

Here’s something simpler that caught my eye, a way of looking at one of the (positive?) effects of this pandemic.

Traffic data shows how rush hour has all but disappeared in major cities in Britain (and ROW) – Reddit
No more rush hour. Declining vehicle usage in cities across the world means journeys at rush hour are almost as quick as those in the middle of the night.

No easy answers

How bad will this get? It’s a simple enough question…

Why it’s so freaking hard to make a good COVID-19 model – FiveThirtyEight
The number of people who will die is a function of how many people could become infected, how the virus spreads and how many people the virus is capable of killing.

Straightforward enough, but the trouble begins when you try to fill in the numbers. Look at the factors and assumptions within just the fatality rate, for instance.

Think of it like making a pie. If you have a normal recipe, you can do it pretty easily and expect a predictable result that makes sense. But if the recipe contains instructions like “add three to 15 chopped apples, or steaks, or brussels sprouts, depending on what you have on hand” … well, that’s going to affect how tasty this pie is, isn’t it? You can make assumptions about the correct ingredients and their quantity. But those are assumptions — not absolute facts. And if you make too many assumptions in your pie-baking process, you might very well end up with something entirely different than what you were meant to be making. And you wouldn’t necessarily know you got it wrong.

There are so many factors as play here. This is the model they end up with. It’s one version, at least.

Over the next few months, you are going to see many different predictions about COVID-19 outcomes. They won’t all agree. But just because they’re based on assumptions doesn’t mean they’re worthless.

“All models are wrong, it’s striving to make them less wrong and useful in the moment,” Weir said.

Excel and the cat’s whiskers

Excel box and whisker diagrams (box plots)
Box and Whisker Charts (Box Plots) are commonly used in the display of statistical analyses. Microsoft Excel does not have a built in Box and Whisker chart type, but you can create your own custom Box and Whisker charts, using stacked bar or column charts and error bars. This tutorial shows how to make box plots, in vertical or horizontal orientations, in all modern versions of Excel.