Damn Interesting – The Clockmaker

October 8th, 2014

I just rediscovered Damn Interesting, a collection of fascinating tales of history, science, and general weirdness.

It’s got a podcast now!
Audio: Damn Interesting – The Clockmaker (24:11)
Article: Transcript and images

It was the middle of a cool September night in Munich, Germany. The year was 1939. In an otherwise unoccupied auditorium, a man knelt on hands and knees chiseling a square hole into a large stone pillar. The lights were out, but a small flashlight dimmed with a handkerchief provided a pallid puddle of light. The man’s chisel was also wrapped in cloth to quiet his hammer strikes. Whenever there was some unexpected sound, he froze. Whenever a truck rumbled past the building, he seized the opportunity to chisel more vigorously. It was exceedingly tedious and slow work. The fellow was a 36-year-old German handyman named “Georg Elser”. But “handyman” isn’t exactly the right word. In his three and a half decades he had cultivated many skills, including clock making, cabinet building, master carpentry, and stone quarrying. And the task at hand required all of his diverse expertise.

In addition, many of the past articles have been read aloud in audiobook form, as reward for donating.
The audiobook comes linked in an email as a series of mp3s, each 1-3 hours long, with the stories back to back. It didn’t include an index, so I made one…
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Singing Bird Pistols

April 29th, 2014

More automata goodness…

Issus coleoptratus

November 1st, 2013

An insect has been discovered with functioning cogs on its thighs!
(alternate article)

Microscope image of cog wheels connecting the hind legs of the plant hopper, Issus. Credit: Burrows/Sutton
A full-body shot of the insect.

The gears synchronize its hind legs while jumping so it won’t have an unbalanced takeoff and spin out of control.
This one must be defective: looks like it has sparks shooting from its butt…
(via the “Science… sort of” podcast)

The Writer Automaton

October 25th, 2013

One of the coolest scenes from the BBC documentary
“Mechanical Marvels: Clockwork Dreams”.

The the entire show is also on YouTube, here.

Building Tar Archives with Maven

August 21st, 2013

Warning: Maven’s plugin responsible for creating tar’s was buggy until very recently. When opening any such tar in 7-Zip, there’d be an error: “There are data after end of archive”.
I’ll get to choosing a safe plugin version later.
First, some background…
Maven is a build automation tool and package manager, primarily for Java. You write your own code as usual, but instead of compiling, you run “mvn clean” and “mvn package”.

Maven will build your project according to an xml config. If you need libraries, mention ‘em in the config, and Maven will download and include them (along with any libs they need).

Hello World

A basic project’s directory tree looks like this.

Demo/src/main/resources/{here's your jar's root}/blah.png
Demo/target/{your jar will be made here}

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RancidMeat: Mongoose

July 16th, 2013

Mongoose is my new favorite mini web server.

No installer; it’s just a standalone executable. When double-clicked, it hosts the folder it’s in on port 8080.

It lurks in the tray, where you can change its settings with a GUI (generating a mongoose.conf file).
Some of its features:

  • It can serve perl/php/etc (checking shebang lines and running the appropriate interpreter, if available).
  • When there’s not even an index.html, it can show directory listings.
  • From a commandline, it can create/edit passwords for basic HTTP authentication (htpasswd).
  • It’ll do HTTPS if you’ve got a certificate.
  • As of version 3.8, it lets wget resume downloads (previous versions didn’t understand wget’s request).

Article: User Manual on GitHub.
Article: Linux manual, for commandline args.

Windows 8 Breaks NTFS in Linux

May 30th, 2013

Warning: A hibernation feature called “Fast Startup” defaults to ON in Windows 8, which leaves the filesystem in an unsafe state every time you shutdown. Based on an assumption that you’ll just boot Windows again next time.

Do not mount NTFS partitions outside of Windows 8 unless that feature is disabled beforehand. For more, see this article.
Future versions of Linux’s filesystem driver will warn about this and suggest mounting read-only.

Knoppix 7.05 already includes a warning for this, though the nag has a cosmetic bug. It tries to spawn a GUI popup, which fails if you booted straight to a console root prompt.

Safe Destroy Callbacks in wxPython

October 7th, 2012

Say you’re writing a wxPython GUI, and you want a menuitem that spawns a popup frame, and that stays disabled until that popup is gone.

The obvious thing would be to do this.

self.popup_frame = wx.Frame(self, wx.ID_ANY)

def destroyed_callback(e):
self.popup_frame.Bind(wx.EVT_WINDOW_DESTROY, destroyed_callback)

Disable the menuitem, spawn the popup, and reenable on destruction.

Problem: What if you close the parent window first?
That’ll also cause the popup to close. But by then, there’s no menu left to toggle because the parent’s gone. You may get a PyDeadObjectError, or the OS will step in to complain. Bad.
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Exotic Mechanics

May 11th, 2012

“Mechanical Principles” by Ralph Steiner (1930)

For more outlandish gear and pulley arrangements, there’s a book called “507 Mechanical Movements” (1896).
Loads of eye candy. Even pages are diagrams; odds are captions.
Read: Google Books
Download: Archive.org
Buy: Amazon

The Real CSI

April 18th, 2012

Frontline aired an episode last night on the rigour of forensics.

(Via Frontline – The Real CSI)
For a bizarro version of the narrative, see
Unreported World – Witches on Trial. It popped into my head both for the unquestioned healer experts and the unreliable witness fiascos that happen when physical evidence is off the table.

* To play that video, the official site irritatingly requires a login (bugmenot to the rescue), but the expandable text synopsis below it is thorough enough.
A previous CSI-related Frontline was more about rigor.

(Via Frontline – Post Mortem)