Cartagen 0.6.1 – Speed

We know we just released Cartagen 0.5 a couple weeks ago, but after testing it extensively in the wild, we really wanted a fast, low-resource release so that users of netbooks, older computers, and older browsers could use Cartagen too.

So, as well as including some general cleanup, this version hums along on a variety of machines. Please send feedback on speed/load times/CPU usage, etc; we tested it on an 800mhz G4 iMac and while it wasn’t super responsive, it did load and was somewhat usable in Firefox 3.5. For reference,’s Flash player does not run on that machine. On more powerful machines (4x3ghz Intel Xeon, 2500×1600 monitor), it can load over 10,000 objects in the viewport without hiccuping. For most users, a typical browser window size yields a responsive and reasonably low-resource experience.

Download Cartagen 0.6.1 (We did 0.6 and just rushed directly into 0.6.1 before announcing.)

There’s definitely a lot more we can do to improve speed, but for now we feel good about our optimizations. We identified the high CPU usage as generally poor management of timers in JavaScript, and wrote a TimerManager class which adjusts its timer intervals automatically, easing the CPU load. We elected to maintain a relatively high CPU usage to keep things rendering smoothly, but users of TimerManager can ‘turn up the heat’ or turn down CPU usage by tweaking a ‘spacing’ parameter. We also broke more intense tasks up by creating a TaskManager class, which preserves UI responsiveness and framerate while staying in a single JavaScript thread. We plan to use the multithreaded, asynchronous Web Workers spec in HTML5 when available, but for now we wanted to work on older hardware/software.

We hope that TimerManager and TaskManager will be of use to others working with JavaScript animation and we’ll be packaging them up separately for download.

For now, look at for source and for update docs.

Warcraft map stylesheet for London

So this is an accurate (in terms of coordinates) map of London, generated from OpenStreetMap data:

[field name=”iframe”]

You can pan around quite a bit and use the scroll wheel to zoom. To achieve this, I created the following geographic stylesheet:

The map is built on Cartagen, a mapping framework for viewing and geographic data in a dynamic, personally relevant way. Cartagen uses the GSS (Geo Style Sheet) format, which allows users to design maps with CSS-like styles. Learn more at and the Cartagen wiki, or download the source at Google Code.

Go to to view anywhere in the world through this stylesheet.


Quick update: some users (read: most) are having trouble zooming in and out! This is because of a known last-minute bug in the 0.6 release of Cartagen, and only affects maps embedded in other pages. It does not affect For a quick fix, to zoom you can also hold down the ‘z’ key and drag up and down on the map.
Followup update: zooming with the scroll wheel should work now. Thanks for your patience!

Announcing Cartagen 0.5

Today we’d like to announce the 0.5 release of the dynamic mapping framework Cartagen. In this release, we’ve taken a shot at rendering any location on the planet (drawing, of course, on data from OpenStreetMap), and at rendering a much greater density of map features with richer styles. The has come a long way, and we hope it makes designing your own map easier while allowing even greater possibilities for unique and compelling designs.

Download Cartagen 0.5

This is the first release we consider to be useable by the general public; as such we are releasing a video to demonstrate how to download Cartagen, get a data set, and write your own GSS stylesheet in just a few minutes:

More information and setup instructions are on Cartagen’s wiki, and our live demonstration site at has been updated.

Cartagen is still incomplete: it needs more optimization for slower browsers and devices like the iPhone and Android phones, it can make better use of HTML5 features such as Web Workers for multi-threaded JavaScript for a more responsive UI, and we hope to continue our early efforts to combine it usefully with OpenLayers and other mapping platforms.

Special thanks to Ben Weissmann who’s joined the Cartagen team and has been instrumental in bringing it this far.

Trees exchanging carbon via fungal networks

Different plant species can be compatible with the same species of mycorrhizal fungi1,2 and be connected to one another by a common mycelium3,4. Transfer of carbon3, 4, 5, nitrogen6,7 and phosphorus8,9 through interconnecting mycelia has been measured frequently in laboratory experiments, but it is not known whether transfer is bidirectional, whether there is a net gain by one plant over its connected partner, or whether transfer affects plant performance in the field10,11.

via Access : Net transfer of carbon between ectomycorrhizal tree species in the field : Nature.

Thanks, Caroline!

Absolute direction in language: Kuuk Thaayorre

To test this idea, we gave people sets of pictures that showed some kind of temporal progression (e.g., pictures of a man aging, or a crocodile growing, or a banana being eaten). Their job was to arrange the shuffled photos on the ground to show the correct temporal order. We tested each person in two separate sittings, each time facing in a different cardinal direction. If you ask English speakers to do this, they’ll arrange the cards so that time proceeds from left to right. Hebrew speakers will tend to lay out the cards from right to left, showing that writing direction in a language plays a role.3 So what about folks like the Kuuk Thaayorre, who don’t use words like “left” and “right”? What will they do?

The Kuuk Thaayorre did not arrange the cards more often from left to right than from right to left, nor more toward or away from the body. But their arrangements were not random: there was a pattern, just a different one from that of English speakers. Instead of arranging time from left to right, they arranged it from east to west. That is, when they were seated facing south, the cards went left to right. When they faced north, the cards went from right to left. When they faced east, the cards came toward the body and so on. This was true even though we never told any of our subjects which direction they faced. The Kuuk Thaayorre not only knew that already (usually much better than I did), but they also spontaneously used this spatial orientation to construct their representations of time.