First of all, stating the obvious: The cost of local storage (in other words, hard drives) has been dropping exponentially for a couple of decades. And, when I say ‘exponentially’ it’s not a figure of speech. Here’s a well-researched graph of storage costs plotted with a logarithmic Y axis by Matt Komorowski:

Matt provides a nice if overly-precise formula for the shape of the curve: cost per gigabyte = 10^(-.2502*(year-1980)+6.304. Fair enough.

I’m now going to take a big leap, and presume that online storage costs are at least vaguely proportional to hardware storage costs. Something like k1 + k2*10^whatever, where k1 is the flat cost of providing the service, and k2 is the factor by which online, networked storage (for a year) is more expensive than local storage (for as long as your harddrive lasts). I’m also going to assume that as data size grows, the relative importance of k1 diminishes, so I’m going to ignore it. Pretty much all the coming math still holds for non-zero but non-gigantic values of k1, anyway.

In any case, Google thinks that k1 is zero too. Look at their pricing schedule:


25G $2.45/month
100G $4.99/month
200G $9.99/month
400G $19.99/month


Once you buy 100G or more, the price is a nickel per gig per month, period. That’s $.60/year. Matt’s curve says that a gig of harddrive space should cost $.02 in 2012, so that gets us k2 = 30.

Another thing that’s exponential is compound interest. Even in these stagnant times it’s still possible to buy a long-term annuity or 30-year bond that produces a non-zero return.

So, picture this: Instead of paying Google $5/month for my storage, I give them three year’s worth of fees all at once: $180. Google invests that money at a rock-solid 1% interest per annum. (I can only assume that Google has better investment opportunities than that, but I’m being as conservative as possible.)

The first year, Google will spend 60 of those dollars, leaving $120. The $120 earns $1.20 in interest, leaving Google with $121.20. In the second year, the storage is quite a bit cheaper, so at the end of year two Google has about $93 left.

A few years down the line, things get interesting:

Looks to me like I didn’t buy three years of storage for $180 — it looks to me like I bought 1,000,000 years of storage. And, I overpaid.

Inflation, explained

My numbers are not adjusted for inflation. That’s OK, though, because the Matt Komorowski curve (officially known as Kryder’s Law) isn’t adjusted for inflation either.

Other things inflate, though. So we need to invest our principal at a rate greater than inflation or k1 will eventually become significant and devour our original investment.

Physics, dismissed

It’s always risky to extrapolate from past data, especially where exponential graphs are concerned. I won’t be shocked if storage /stops/ getting cheaper in my lifetime. Fortunately, though, the inflection point in the cost graph is in 2022. At 1% interest, we only need the current trend in storage cost to continue for a decade. If we’re able to invest at 3%, the graph inflects in 2019.

So, we don’t need current technology trends to continue forever — just for a few more years.

From the USDA's Dietary Guidelines for Americans, http://www.dietaryguidelines.gov/DGAs2010-PolicyDocument.htm

I am fascinated by this chart, and I’m not sure what to say about it except “sounds about right.”

At first glance it looks like folks are getting most of their calories from grain and chicken which, environmentally-speaking, is pretty good! I imagine there’s a fair bit of red meat concealed in the ‘pizza,’ ‘taco,’ and ‘pasta’ categories, though.

Zoom and enhance...

I’ve just attended an Open Source conference. I missed the boom in ’99 and have mostly worked on deeply unpopular projects, so my expectations for a software conference include attendees numbering in the dozens and sessions in cramped basement rooms at budget hotels. This was not like that.

Rave-themed reception with open bar; tasty snacks; two friendly ladies in outlandish (though modest) outfits hired to smile at developers; lots of coders struggling to carry on technical conversations despite competition from base beats and abundant drink

The first three days of the conference was the ‘design summit’ which meant that essentially only contributing developers were invited. There were 400 of us, and not one of us paid a cent to be there. In addition to feeding and housing our sessions at the Hyatt, various contributors also sponsored multiple open-bar receptions every night.

It’s not clear if all the cash blowing around this project reflects actual potential revenue, or if it’s just a repeat of poor 90′s-style judgement. Earlier today I argued that it was the former, but that was before I had to fight my way through a couple of dozen dot-com-promoting engineers dressed in pink gorilla suits.

Zoom and enhance...

I bet that even now some banker on the east coast is reading an email titled “URGENT: Mascot-based promotion” and calling his wife to tell her not to wait up.

For a while there, my camera would only take photos like this one.  It seems to’ve fixed itself now.

Anyway… There’s a nice site here which lists Bay Area hikes that are transit accessible.  There are lots!  The above garbled photo is from the Marin Headllands, basically right on the other side of the Golden Gate.

Pretty good! Although, I always thought that the point of ‘a la juive’ was that you could eat all of the leaves, which was not quite true with this one.

Courtesy of Woodhouse Fish Company on Fillmore in San Francisco. They also had excellent Ipswich clams, though I’m unclear on why there aren’t equivalent West Coast options. It feels a bit silly to eat seafood on the West coast that was flown in from the East.

He was in the middle of some cross-country bike trip and decided that he should climb Huangshan on the way, and was nervous that someone would steal his bike while he was climbing. So, he carried his bike with him on his climb.