This evening, after our regular hackerspace meeting, we got together for the Calgary Dorkbot meeting for July. And let me tell you, it was like being 9 years old again. So much fun. If your city has a Dorkbot, do yourself a favour and head down to their upcoming meeting. You will only regret if you suck. Continue reading
Most right-thinking people today consider the preservation of endangered species to be an ethical imperative. The underlying assumption (correct in the vast majority of cases) is that the endangered species have been brought to the brink as a result of careless human activities. Habitat destruction, hunting, pollution, and other aspects of the modern industrial age have stressed the biosphere so heavily that some ecologists consider it to be a mass extinction event. One of the many animal species facing extinction in coming years is the Tasmanian Devil. However, unlike many others, the Devil is going extinct because of a naturally occurring pathogen: Devil Facial Tumor Disease. This raises an interesting question: Should human beings always seek to prevent the extinction of animal species, regardless of the cause of that extinction?
Short post tonight, as I’ve spent the day just reading and relaxing (AND FREAKING OUT ABOUT THE STUPID WATERMARKS IN TELESCOPE IMAGES THAT THE GOD DAMN REGENTS OF THE UNIVERSITY OF CALIFORNIA REQUIRE SCREWING UP MY RESEARCH).
As some of you, dear readers, may be aware, I enjoy carousing among the various steampunk hangouts of the internet, and making my own projects from time to time. One of the big bitchfests I see whenever someone posts some new steampunk projects is that it looks like you just glued some fucking cogs onto something. Now, I too find that a pair of plastic Nike sneakers with gold paint and strips of fake leather hanging off to be a bit straining on the imagination’s attempts to picture said artifact as something from an alternative industrial revolution. However, I think that the complaint is actually two complaints, cleverly mashed together into one ugly Harvey-Dentesque complaint. First, there is the complaint that the work is ugly. Now, we all agree that beauty is subjective, etc, etc. but the whole idea in having an aesthetic category like “steampunk” is that the things in that category share common features. And dripping hot glue is not one of those things. I would be glad to see a world free of ugly things! Secondly, there is the complaint that what has been added adds no functionality to the original item (or in the case of scratch-built items, is useless). Also, no complaints from me!
However, I think the complaint is only really fair if it is leveled at both aspects simultaneously. There are plenty of works out there (Jake Von Slatt’s keyboards are a perfect example) of beautiful modification that takes a mundane object and elevates it to a piece of art. And I don’t want to see that kind of work go away. There are also wonderfully clever bits of automata and other lovely bits of technology that are fiendishly clever at what they do, yet still seem a bit cobbled together. I don’t want to see that go away either. Prototyping is important, and often form must follow function.
So, if you find yourself burning with the urge to glue cogs to your hat, stop. Ask yourself: am I doing this to make it beautiful, or am I doing this to make it work better. If the former, it better damn well be beautiful. If the latter, it has to actually do something. Of course, don’t take this as a discouragement to go tinker! Just think of it as a bit of an explanation if people don’t fawn over your latest creation.
After my friend rm’d a bunch of code yesterday, I offered to help. I first made a copy of her disk using dd, copying it off of her machine and using ssh to take it to another:
sudo dd if=/dev/sda1 | ssh USER@HOST "dd of=/home/USER/backup.img"
I then grabbed a copy of sleuthkit, and used the fls tool to find the inodes pointing at her old files, and icat to restore them. I new the files were php code, stored in /var/www so I used grep to select those results from all the files listed by fls. Using grep, I selected the inode numbers from the output, and piped the results to icat.
for i in `fls -r -d backup.img | grep var/www | grep \.php | grep -o [0-9][0-9]*` do icat $i > $i done
Voila, I had a bunch of files, 6 of which were the missing PHP files! Super easy, and thank goodness the filesystem was ext2, as ext3 is much harder to recover data from.
This afternoon, about 10 minutes before the end of the day, one of the undergrads working in my lab turned to me and asked what the command to undo an rm command was. I blinked at her, and told her there was none. I’m now trying to sift through a disk image dumped from the machine she worked on after typing rm -r * in the wrong terminal. Now, backups, backups, etc. I know. But even with regular backups, an rm -r * in your home directory is never fun. If you want to not experience the joys of watching your files turn to dust, add this to your .bashrc:
alias rm="rm -i"
This won’t save you every time, but it will at least prompt you before you blow away 3 weeks of work. So don’t ignore the prompt. Please?
I’ve been thinking of writing an astronomical toolkit for Arduino, to help users build their own go-to telescope mounts, satellite trackers, heliostats, and other cool amateur astronomy equipment. As anyone who has ever worked with astronomical coordinate systems know, since astronomers treat the sky as a 2 dimensional spherical surface, most calculations involving positions on this surface involve a good deal of trigonometry. While the Arduino library includes built-in functions for sine and cosine, it lacked the inverse trigonometric functions arcsine and arccosine. These are necessary if you ever need to convert a length ratio into an angle. It is impossible to convert between different sky coordinate systems (like Horizontal and Equatorial, the two most common) without access to these functions. In today’s post, I’ll show you how I wrote my own arcsin() and arccos() functions using Taylor polynomials.
One week down, 13 to go. To be completely honest, I’m already starting to feel some trepidation at having to come up with topics for each day. I’m finding myself wishing I was more creative, a better writer, and doing more things. This is a good thing, however, as desire is the first cobble on the road towards achievement. Hopefully this project will succeed in its goal, and help me become better at other projects as well as becoming a better blogger and writer. I’ve found myself going through the halls and storerooms of my mind for projects that I once wanted to do, but gave up on because of laziness or procrastination. I’m trying to apply the principles of Bre Pettis’ Done Manifesto to my hobbies, and so far it has been going alright. I swear, though, for all the joy the internet brings me, it really can be a quagmire of instant gratification that leaves me feeling foggy and unfulfilled. I need to disconnect some times, just so that I can work on the other things that cheer me up and make me feel like I am getting things done. Even if those things are installing linux distros for fun, or building useless robots.
I used to have a relatively long commute in to work, with a 30 minute drive and a 15 minute walk (I am cheap, and hate paying for parking). Because I have the attention span of a 6 year old meth addict, making this trip without something to listen to was unacceptable. So, I developed a insatiable addiction to podcasts. Here are the ones I listen to regularly.
Continuing my series on using python and matplotlib to generate common plots and figures, today I will be discussing how to make histograms, a plot type used to show the frequency across a continuous or discrete variable. Histograms are useful in any case where you need to examine the statistical distribution over a variable in some sample, like the brightness of radio galaxies, or the distance of quasars.
So, yesterday afternoon, I rode my bike down to Oolong Tea House in Kensington (if you are Calgrian, go there. It’s my favourite hangout in the city) and picked up a copy of Alejandro Jodorowsky and Moebius’ 1981 classic, The Incal. And woah boy, let me tell you, it has been very enjoyable. I’m only just over halfway through, but it so far I am totally engrossed.
If you like cyberpunk, space opera, and crazy psychedelic/new age sci-fi stories, do your self a favour and go buy a copy. Blade Runner, Akira, and The Fifth Element are all hugely influenced by this fantastic book. Just make sure you don’t get screwed over with a bowlderized edition. Moebius’ art is spartan by modern standards, but it is absolutely gorgeous, far too beautiful to let it be ruined by the crude hands of censors. I got the Classic Collection, which you can pick up on amazon for just under $50. It’s a 307 page hardcover full-colour book, so the price isn’t as outrageous as it seems. Well, if you’ll excuse the short post, I’m off to read more Incal!