With Love and Geo-hashing

xkcd is a web comic of romance, sarcasm, math, and language.

Who's responsible for xkcd?

Randall Munroe has been writing xkcd for at least five years. Maybe longer.

Unknown territory of love and math

He describes himself as

... just this guy, you know? I'm a CNU graduate with a degree in physics. Before starting xkcd, I worked on robots at NASA's Langley Research Center.

What do the letters x-k-c-d stand for?

Is it an abbreviation or an acronym? Mr. Munroe says:

It's not actually an acronym. It's just a word with no phonetic pronunciation -- a treasured and carefully-guarded point in the space of four-character strings.

Regarding the matter of sorting algorithms, if in a quandary about which to use (because they taught you so many) Mr. Munroe observes:

This is tricky. Most of what they teach you in school is just as an example of how to think about algorithms; 99% of the time you shouldn't worry about optimizing your sorts. Just learn to implement Quicksort (which is very good) and use that without fretting about it too much.

Geo-hashing 
achievement 
badge

Note: If you're interviewing for a company for a position with a focus on algorithms, the above is not an excuse not to know your stuff.

xkcd also offers an interesting little game.

Let's go geo-hashing!

Geo-hashing involves meet-ups which accomplish the admirable goal of getting us away from our computers, getting out doors, exploring the great wide open. That is not the stated objective of the game, merely my editorial commentary.

It resembles geo-caching but is a bit more complex, at least up front. Overcoming the initial hurdle is a completely sedentary activity. It only requires careful study of the instructions.

I confess that I haven't tried it, but it seemed at least as pleasant as geo-caching.

The xckd wiki provides complete details, including detailed accounts of many years of past geo-hashing events. I noticed that these geo-hashing excursions were held, literally, all over the world.

The Algorithm as shown in xkcd comic #426

CC 2.0

The Algorithm captures the basics. I confess that I understood it very briefly, then not at all. But the wiki is extensive, and explains the rules quite clearly.

Randall Munroe is actually quite a talented illustrator. I scattered a selection of his geo-hashing illustrations throughout.

*All of Mr. Munroe's work is  reproduced here under terms of Creative Commons License 2.0, see icon above.

Microsoft Tag at the Crossroads of Virtual and Physical Worlds

Will Microsoft clear the field as it enters the location-based service market? Microsoft provides this definition of Tag, whose scope is larger than I realized:

"A Tag is a high-capacity color bar code... Organizations and individuals can create specific Tags by using the Microsoft Tag Manager Web service. When the Microsoft Tag Reader application is installed on a mobile device, [it] can be used to scan a Tag using the built-in device camera. When a Tag is scanned by the Tag Reader, the information encoded into the Tag becomes available on the mobile device."

Cyber sheep?

A tag is similar to a QR code. A tag must be

• created and placed so that users can locate it in the physical world, NOT the virtual world of the interwebs AND 
• rendered with adequate size and detail so it may be scanned accurately by mobile device cameras.

The purpose of this was not obvious to me. I had to approach it in steps.

Tag taxonomy

Let's start by defining a tag as a descriptive word or phrase associated with a noun, verb or idiom. I think of these as basic "virtual tags". Examples would be the word or word expression description associated by customers with Amazon.com merchandise. Since my own cognitive processes are driven by analogy to basic concepts learned, well, in elementary or middle-school, I think of a tag as a super-synonym. Better yet, a tag is a synonym with a promising future.

This is a mini-taxonomy of virtual and real-world tags:

• Virtual Tags describe people, animals, objects and actions, but are applied within the virtual world, usually the internet.
• Virtual Geo-tags are specific to physical location, and usually correspond to geo-spatial coordinates (GIS). Examples are the inverted teardrop place markers used to indicate locations in Google Maps and Mapquest. This type of tag is a virtual construct, despite its reference to a physical location.
• Microsoft Tags are physical objects. They are associated with specific geo-spatial data, i.e. geographical locations in the real world. Using the Microsoft tag reader and a mobile phone camera, these physical Microsoft Tags can then be converted to Virtual Geo-tags.

Comprehension increases after viewing the image gallery of Microsoft Tag examples created by current users, or the implementation guide for web and mobile phone users. The latter is available as a PDF download.

Microsoft is offering its Tag service free of charge. They make no promises about the future though.

Intersection

Microsoft Tag reminds me of Floating Sheep's visualization of the urban cyberscape, or maybe "cyberspace". Floatingsheep is focused on mapping and analyzing:

"a hybrid place: the online extension of the socially constructed human landscape in which the lines between material place and digital representations of place blur."

The internet is evolving at a brisk clip.

Urban Cyberscape

The image above, which seemed fanciful a year ago, is growing into a reality with QR codes and now Microsoft Tag.