So, we’re back on the air.  Stay tuned….

(click for the full mosaic, 1,300+ books in all!)

Yes, that’s a geeky thing to do. But it highlighted a few things about my changing “digital existence” that I thought were worth reporting:

So Much Data
First and foremost, all of this data (the books, the covers, and even the photo I turned into the mosaic) were available with a few minutes worth of work. Admittedly, I had previously spent hours scanning the ISBN bar codes on my books (conveniently when packing my books in order to move to my new apartment). But think about the amount of data available to me for very little investment: the titles, authors, and graphic images of 1,300 some-odd books, along with their associated meta-data (length, ISBN, etc.). When I was in school (ending in the mid ’90s), gathering and manipulating this sort of data was certainly possible, but doing so was the domain of database experts, programmers, and the like. So I became one of those, mostly because I saw the computer as a tool which would facilitate information manipulation of a nature never previously possible−or indeed imagined.
Trumbull College, My residential college at Yale, for example, had a library boasting some 5,000 works. Its card catalog was positively ancient and poorly maintained. Estimates for the workload involved in cataloging it and keeping it up-to-date were so substantial that the (volunteer) project never got off the ground. A mere fifteen years later, my catalog is not only mostly up-to-date, but it contains all manner of “rich content” that a card catalog could not muster: images of the covers, other books by the same author, publication history, and of course the meta-data: reviews, social/popularity information, and even feedstock for inference and recommendation engines.

Community Creativity
Then there is the accessibility of the inspiration. LibraryThing cleverly suggested the mosaic and linked to David Louis Edelman‘s post in which he created a similar mosaic. Call it community scrapbooking, community arts and crafts, or simply community creativity, but this sort of cross-country “we all trade inspiration” is unusual, to say the least. To be sure, historically artist communes and even local arts and crafts fairs historically provided fodder and inspiration for our individual creativity, but this is a different kind of inspiration: it is both more instantaneous (I got the idea late last night; got a full night’s rest; and woke up and produced the mosaic before breakfast this morning) and more eclectic (David is a computer programmer and Science Fiction author in the Washington, DC area; I am a technology company CEO in Silicon Valley).

But Silos—Still
Unfortunately, it’s not all wine and roses. LibraryThing is the site I’ve always used to catalog my books, but recently Visual Bookshelf has won many converts, mostly because they have embraced the Facebook Platform API and have created a Facebook application. Since some 500 of my friends are on Facebook, and since many of them are avid readers, Visual Bookshelf has already netted me 40 some-odd “reading buddies” (which I define as other people I am friends with on Facebook and who have Visual Bookshelf profiles). An 8% cross-over rate isn’t bad, especially when you consider that Visual Bookshelf is only one of hundreds of Facebook applications. (And, for that matter, it’s one of the least annoying, since it doesn’t spam the hell out of your friends.) Here, for example, is my bookshelf, as displayed on Facebook, and what my friends are reading:

Unfortunately, I cannot synchronize my book activity on Visual Bookshelf with my LibraryThing account. Visual Bookshelf finally implemented a LibraryThing import feature, but it’s unidirectional. Likewise, Facebook makes it nearly impossible to export friend information (going so far as to display email addresses as images to foil screen scrapers and other brute force export tools). So I’m stuck maintaining two databases and importing one to the other, potentially over-writing or losing information each time I do so.

Of course, I’m not the only one who has noticed this problem, and it is but one example of the growing “problem” of social networking data living in proprietary silos. Such well-known Web 2.0 commentators as Om Malik have even gone so far as to propose that social networking features will end up getting built into most desktop and web software, much the same way as the Cut/Copy/Paste mechanism has become a de facto paradigm standard. But that will only work if the core social networking information (who is who and who knows whom) does not remain the proprietary information of, e.g., Facebook. Technologies from the simple XFN to the ambitious OpenSocial are supposed to fix that, but OpenSocial appears almost to have been promulgated by Google to compete with Facebook, and it will be a chilly day in the netherworld before Facebook adopts it. More recently, the DataPortability Working Group has been graced by the participation of Facebook, Google, Microsoft, and others (or at least representatives from those companies). But until something concrete develops, we early adopters will continue to enjoy the benefits of So Much Data and Community Creativity, but only if we’re willing to put up with duplicate data, lost data, and the other assorted horrors of manual synchronization.

All told, the information revolution continues in directions we never could have anticipated. Here I am trading notes with friends I haven’t physically seen in over a decade, enjoying better book recommendations from the wisdom of my friends (and the crowds) than I do by poking around my local bookstore, and finding a nice Sunday morning arts and crafts project inspired by a Washington, DC science fiction author whom I’ve never met.

Now if only I didn’t have to keep three copies of it all!

Those of us who live near the Hayward Fault, which runs to the East of Silicon Valley, have known for a while that we are “overdue” for a quake (with apologies to the Wizard of Odds—yes, of Odds—for flirting with the Gambler’s Fallacy). [Aside: anyone remember that great '80s Bond film with the man-made Silicon Valley earthquake?]

When the quake hit, I was having dinner with two colleagues from work, one of whom had been around during the much more serious Loma Prieta quake in 1989. That one measured about 7.1 on the Richter Magnitude Scale. Most people know that the Richter scale is a logarithmic scale, but many don’t realize that the scale actually provides two different output values: the physical displacement at the fault location goes up by a factor of 10 (i.e., the log is to the base 10) for each single unit of increase, but the energy released goes up by a factor of 32 for each single unit increase. Thus the ’89 Loma Prieta quake was approximately 181 times more energetic than today’s quake.

A truly astonishing amount of information was immediately available about today’s quake, thanks to automated processing and reporting of seismic events. For example, here’s a map of all the recent earthquakes in California from the USGS. (The large blue rectangle is, of course, the quake in question. Note the smaller aftershocks.)

The detailed report on the quake confirms that the sophistication of automated earthquake analysis is truly impressive. Want to know whether there’s a tsunami risk? Read the Tsunami Message from WCATWC. (No risk.) Or how many people in your neighborhood felt it? Read this map. (84 in Mountain View.) Or what the ground looks like above the epicenter? Check this out:

This is all particularly interesting to my colleagues and to me because the mathematics used to locate earthquakes (by seismic triangulation) are pretty much identical to the mathematics use at ShotSpotter to locate gunfire (by acoustic triangulation). Both techniques are fundamentally based on the difference in time of arrival of a transient signal (the seismic or acoustic wave) at sensors located in different places. Based on this difference in time of arrival (also known as TDOA, or time difference of arrival), a series of hyperbolae can be plotted, and the intersection of these hyperbolae will be the origin of the transient. Why hyperbolae? Hyperbolae are “curves of constant difference in distance” between two points, or foci. Wolfram has an excellent article explaining them. So, geometrically, if you have two different points F₁ and F₂, then there is a hyperbola is the set of all points whose distance from F₁ and F₂ always differs by a specific constant, which we can call k. In the diagram below, for example, the difference between the distances r1 and r2 will equal k, as will the difference between the distances r3 and r4.

The physical interpretation of this k is straight forward: it is the difference (in time) between when someone standing at F₁ and someone standing at F₂ would hear a noise which originated somewhere on the hyperbola.

If you have only two points (F₁ and F₂ ), then you have a single hyperbola. But if you have three points (F₁, F₂ and F₃ ), then of course you have three hyperbolae, reflecting the difference in time of arrival at the three points (F₁/F₂ , F₂/F₃ , and F₁/F₃ ). This diagram, from Suruj Dutta’s site explaining the technical underpinnings of location-based services, shows how cell phone triangulation works and gets it mostly right, although it only shows two of the three hyperbolae:

Moreover, the reflections and “echoes” caused by different geologic layers of the earth are quite similar to the reflections and echoes caused by the complex urban terrain in which ShotSpotter systems are deployed.

I finally lost patience with the limitations of Blogger and switched to WordPress. Along with the switch came a complete visual redesign, as well as the requisite re-posting of my prior posts and some ancillary dusting and clean-up. For those who don’t know it, WordPress is a superb blogging engine, built on PHP and MySQL (and often hosted on a web server running Apache). It’s a testament to the maturity of the tools today that I was able to get WordPress running on my Windows XP laptop as a test environment (which meant running PHP and MySQL, but using Microsoft’s IIS as the web server) in about two days (minor MySQL learning curve for me, since it was my first experience), and then that I was able to get the whole stack up and running on my hosting provider, BlueHost, in about half a day.

Building themes and functionality beyond the “out of the box” stuff in WordPress requires a working knowledge of CSS, XHTML and some PHP. I had the first two, but this was my first real exposure to PHP. So, off to the bookstore I went, and came home with O’Reilly’s Learning PHP 5. I read it, as I usually do with computer books, in one evening