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Blog posts tagged as 'citytracking'

Totems and City Avatars


At one point during City Tracking, I commented that I still felt a connection to London during my time in San Francisco through the bike-key on my keyring (above).

(If you’re not aware of London’s cycle hire scheme – it’s a system of bike rental whereby bikes, distributed between docking stations around the city, can be unlocked with a plastic “key” and a small fee. It’s similar to Paris’ VĂ©lib).

I suppose that could have mentioned my Oyster Card, but that usually lives tucked away in my wallet. The bike-key was something I touched several times everyday; it acts as a kind of key-fob for me.

I mentioned that, for me, the key acted as a kind of what Mike Kunivasky calls a Service Avatar. As Mike explains in his Microsoft Social Computing Summit talk:

“…because these things are now connected, their value moves from the device to the service it represents, and the actual objects become secondary. They become what I call service avatars.”

Mike is talking about electronic devices like digital cameras and TVs at this point in his talk – things that have functionality within them that is then connected to a service.

The bike-key has no functionality without the service: it’s just an RFID tag inside a piece of plastic. The service itself is unavoidably located in London. The computer systems that run it do not have to be, but the bikes themselves – the critical hardware within the service – cannot be located anywhere else.

The city and the service are tied together.

And so, for me, that keyfob that I pass through my fingers when I pick my keys up, or fidget with them in my pocket, is not just a service avatar; it’s an avatar for a city.

Then, of course, I have to unpack what I mean by “city”: not only the architecture and built environment, but also: the people within it; the transit systems that I experience so much of it through; the service layers including power, utilities, and even the payment schemes such as Oyster; the many digital layers on top, Foursquare and Gowalla and geotagged photos on Flickr and so forth.

The bike-key touches all of these: the built environment of the roads, the transit map, payment services, the digital infrastructure. It’s not just an avatar for a single service; in some ways, it’s an avatar for the entire “stack” of the city.

Time for a slight confession.

When I described the bike-key, I described it as a totem of London that I carried with me. When I said that, I wasn’t really referring to the traditional notion of an object describing the structure of kinship groups – although there are definitely comparisons to be drawn there, which Elizabeth Goodman touched on in her session on the final day.

My reference was more rooted in popular culture.


In Christopher Nolan’s recent film Inception, characters keep “totems” – small objects that behave in recognisably unique ways that only their owners know – to prove that they are truly in the real world to themselves (as opposed to being in one of the dream landscapes in which much of the film takes place).

All the totems seen in the film are objects with particular physical qualities – a spinning top, a loaded die, a poker chip, a weighted chesspiece – that behave in very particular ways (toppling, spinning) when subjected to the laws of real-world physics. Their totems prove that the laws of reality are in effect.

Nolan’s “totems” are reminders not just of the real world – but of the system that world runs on.

The bike-key in my pocket is a totem reminding me of larger systems – both the London bike network, and the city itself.

In San Francisco, it was a tangible reminder that London is still there, even though the key had no functionality in this particular city. Returned to London, the plastic key regains its powers, and returns to its normal behaviours: unlocking bicycles, capturing my usage of those bikes in its system.

As the city becomes increasingly networked – as Adam Greenfield describes eloquently in this post on the Urbanscale blog – there will inevitably be parts of that network, and thus parts of the city, that I can take with me.

On my keyring, everywhere I go, I carry a piece of London.

Four Thousand Years of Urban Growth

Chandler book cover

In his opening session at City Tracking, Stamen‘s Eric Rodenbeck showed us this book. Tertius Chandler’s Four Thousand Years of Urban Growth is a historical census of the world, derived from almost any source Chandler can find.

The book sat on the front table in the room we were sharing for the duration of the conference; a constant reminder of cities past and present, fallen and still-standing. I spent some time skimming through it, and found its contents as marvellous as Eric intimated.

In the first section of the book, Chandler tours the world, listing individual cities and their populations over time.


Here’s some of the listing for Dieppe, in France.

As well as a running total, there’s a citation for how that figure was derived. Sometimes, it’s based on direct quotation. But sometimes, it’s based on something more like a calculation. For instance, that 1600 figure for population is based on the number of churches in the city, and the average congregation size for those churches.


Here’s some of the listing for Baghdad, around the 8th century AD. In 932 AD, he uses several sources: the number of doctors (and how many citizens they served); the number of baths in the city; and the area the city covered. His final figure – of 1.1 million – is closest to the estimation derived from area. Chandler includes other figures in his notes, even if he’s not comfortable with their accuracy; see, for instance, the “reputedly 2,000,000” in 833, derived from the 1910 Encyclopedia Britannica. Chandler is clearly happier with the more conservative estimate derived from the area in the 1960 Encylopedia of Islam.

City tables

At the end of the book are tables of the world’s largest cities listed by era, with their populations. These are some of the listings for a few thousand years ago.

Finally, there’s a short textual appendix that serves as a short biography of the forty largest cities in each century, from 100-1970. From all his numbers and tables, Chandler weaves a narrative of how the world’s powers and economies have shifted and changed. For instance:

“China dominates the first city tables. At 1400 and 1500 it has each time 11 of the 40 cities. At 1600 China still has the topmost place, and 2 of the top 10, but Spain, with only one in the top 10, barely trails China overall with 6 to China’s 7. The Spanish cities include 1 in America, 1 in Portugal, and 3 in Italy. In 1700 China is ahead again with 9. In 1800 it has 9, as to 10 in the burgeoning British Empire, albeit the latter has only 1 on Britain itself. Britain and China thus rule just under half of all the 40 cities at 1800…”

It’s a marvellous artefact that’s now sadly hard to track down. As Eric quite rightly noted, those neat tables are crying out to be digitised in some form. It was kind of Eric to share Chandler’s remarkable book with us (and to let me share it with you) – and as a starting point for two days of talking about cities, it felt most appropriate.

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