Race against Time

In honor of New Year’s Day, I’m posting a snapshot from the “1-D Space Rally” game from a collection of Java applets that illustrate relativity. Joel Primack created the applets based on a series of interactive programs originally created for the Apple II.

Y’see, I’ve been reading The View from the Center of the Universe, written by Primack and his wife. I quite like the book, which attempts to put cosmological concepts in a more accessible framework, drawing on historical imagery and metaphors to help readers understand, as the subtitle puts it, “our extraordinary place in the cosmos.” Because Primack has played an active role in developing the cosmological concepts that form the core of the narrative, the content is first-rate, and the richness of the analogies terribly impressive. (Plus, Primack and Abrams’s “Cosmic Spheres of Time” figure resembles the interactive Digital Universe model that I work and play with on a day-to-day basis.) The authors have a website that supports the book’s content as well.

Anyway, the image. As it says in the introduction the aforementioned applets, the interactive “helps demonstrate why the ‘twin paradox’ is, in fact, not a paradox.” The curving red line represents the trajectory of my rocket (seen at bottom), while the green lines show pulses emitted at regular intervals—intervals which differ for the rocket and the point of origin because of relativistic effects. I did my best to fly as far from the starting point as possible before reversing and returning to the starting point; as a result, only 360 units of time passed on the rocket compared to 582 at the origin.

I like the interactive well enough, but I have it could use a little more documentation, and I have one major nitpick, clearly visible in the above snapshot: label the axes! The vertical blue line represents time, while the horizontal line represents distance; they should be labeled as such.

I found a few problems with some of the other interactives as well (light pulses that don’t travel at a consistent speed and an apparent lack of gravitational influence from Jupiter, for example). I’d be interested to know whether or not those details cause misconceptions for people who use the interactives. Perhaps a generation of students (on Apple IIs, even) could provide feedback.

Sadly, no near-light-speed spacecraft exist to help us travel into the future, aging more slowly than our earthbound compatriots. So as we celebrate a new year, we all celebrate together, growing older at the same depressing rate. At least we can simulate an alternative…

Happy new year!

Breathing Earth

A frequent reader of this blog just pointed me to the “Breathing Earth” website, from which I took the snapshot pasted above. The site takes data about countries’ birth and death rates as well as carbon dioxide emissions and incorporates them into a single, interactive map of the world. Births and deaths show up as flashes on the world map, while the color of a country represents its carbon dioxide emissions.

What the snapshot above doesn’t show is the interactive bit of the site, which allows you to mouse over a country to learn about its particular birth and death rate as well as its carbon dioxide emissions. Plus, it features a running tally in the lower left-hand corner that shows how many people have been born, how many died, and how much carbon dioxide has been emitted since you personally opened the web page.

Overall, this strikes me as a spiffy visualization, and my initial inclination is to see more data represented—perhaps not all at the same time, since I would hate to see the pleasant design marred by overcrowding, but maybe as options. In other words, it seems like a good template. One of the challenges of presenting only a few data elements is that it suggests a causal connection between them, whereas having a more generous set of options would allow the user to explore more on her own. In terms of the content actually presented, I’m a little confused by what the color of the country really means, since the caption reads variously “country has emitted over/less than 1000 tonnes of CO2” and “is currently emitting more than 1000 tonnes of CO2.” The last statement is meaningless, since “currently” would require some rate of emission, not simply a quantity. So it seems that it could use a little more detail in the captioning.

(Then, on an utterly nitpicky note, the regular gridlines of the above image suggest a Mercator projection, but the layout of the geography looks more like the traditional Robinson projection. That annoys me, but I’m easily annoyed that way. For more on map projections, BTW, you can take a look at the “Geographer’s Craft” page or the more detailed but less complete page at USGS. For the truly anal-retentive, check out Hans Havlicek’s page for more information than most of us ever need on the topic.)

I actually took a very different approach to visualizing socio-economic data in an “art” piece I created as an interactive and for fulldome video. I dropped the map and put elements into a very abstract space, hoping to see patterns that could work on both an aesthetic and an intellectual level. Dunno if I succeeded, but I entitled it “Numerology 0.1,” if that gives any sense of how I feel about it.