“Parkour Cars” – real-time autonomous vehicular acrobatics

Nima Keivan’s research project is incredible. It involves an autonomous toy car that navigates through an array of obstacles, including loops and enormous jumps. It uses an open-source physics engine (Bullet) to project forward in time the result of taking multiple actions and uses the results to make the optimal move (e.g. what will happen if I turn left .5 degrees, or stay straight, or turn right by .5 degrees).

Learn more on the project page or check out the PDF for more details. Thanks to Jack Morrison of Replica Labs for the link.

CodeSchool / Rails for Zombies impressions

CodeSchool is a site designed to teach programming skills in an interactive fashion. I went through their free course offering, Rails for Zombies, yesterday and was thoroughly impressed with the offering.

Rails for zombies image

The course consists of 5 sections, each introduced by an extremely well-produced video segment. At the end of the video there is an interactive lab in which you must successfully code solutions to questions covering what was just discussed in the video. For instance, in a section on Rails Routes, it might ask you how to add a global redirect from /all to the page /tweets.

Right now the site is very web development focused, but I’m looking forward to when they start having classes on other topics/languages.

I recently completed a course on School of Webcraft, and while the experience was a good one, it was nowhere nearly as nice as that of CodeSchool. In particular, the awarding of badges for having completed certain tasks is automated and instant on CodeSchool; in P2PU a human must manually acknowledge that you’ve completed all the requirements. In my case I’ve been waiting over a week for that recognition.

I highly recommend checking out CodeSchool, even if you don’t plan on paying for a course. The Rails for Zombies example is free and definitely worth the approximately two hours it took to complete.

Cut/Paste bug in Google Docs Spreadsheets

Video illustrating the bug

I use Google Docs Spreadsheets frequently and love the ability to collaborate on the same spreadsheet with multiple people currently.  The automatic versioning is excellent as well.

There is an extremely annoying bug that plagues at least the Chrome/Firefox versions of the application running on Mac OSX 10.6.6; I am posting here with the hopes that more people up-vote my support ticket and the bug is resolved sooner.  See the full bug ticket here.

In a nutshell, the problem is that the cut keyboard shortcut (⌘X) acts differently than the cut context menu.  When you fill the cut buffer via the keyboard shortcut and paste it via the paste keyboard shortcut (⌘V), things work fine.  When you later cut a different row/cells via the Cut context menu and paste with the keyboard shortcut, the original text you cut via the ⌘X shortcut is pasted instead of the text you just chose to cut.

It’s easier to see what I’m talking about via screencast; see this video for a minimal example of how to reproduce the bug.

I’m interested if this plagues Windows users and those using different browsers.  Please post in the comments with your results.