Year: 2010
Type: editorial
Abstract: The pulse of the city All human and natural events in motion are reflected in cities.Until quite recently we relied upon human recording of these motionsöon histories which inevitably incorporate the perceptions, fallibilities, and limits of ourselves as observers.Our sense of their importance could only be culled by arraying the relative frequency of their reporting against our own personal experiences.More `objective' and automatic measurements of change have only existed en masse since the industrial revolution and, until the invention of electricity in the 19th century and thence the silicon chip fifty years or so ago, reliable and extensive automated recording had minimal significance.This began to change with the development of the Internet.Its access through wireless devices with geopositioning systems that can be incorporated into ever-smaller recording instruments is now enabling individuals to record their motion at specific locations and on a continuous basis.This revolution in tracking human and other motion in digital form enables the collection of multiple attributes at the finest of scales of urban observation.The processes of collection are invariably highly decentralised by organised and usually controlled dispersion of such sensing devices or by less controlled individual activity motivated by personal interest which involves the collection of information using what is now called `crowd sourcing'.This extends well beyond geography, however, to the collection of much nongeographic information which is nevertheless tagged to place and hence understandable in both spatial and temporal terms.Superb examples of how such data can now be mined to construct order and pattern in the city involve processing photographs of people and places from the online site Flickr.Maps of the city based on the density of photographs, not the photographs per se, are appearing everywhere, a recent example being Eric Fischer's photostream work of 116 maps of big cities (see http://www.flickr.com/photos/walkingsf/sets/72157624209158632/).Even more remarkable constructions from Flickr involve the use of multiple photographs from various positions to construct the 3D structure of the city, with excellent examples such as famous ancient buildings being generated at the GRAIL Laboratory in the University of Washington (see http://grail.cs.washington.edu/rome/).These kinds of data logging and mining are growing rapidly, but their temporal frequency is beyond real-time actions and motions.In short, their analysis is possible only after the events have taken place and when a sufficient volume of actions has been built up.Digital data which preserve their real-time structure are rather different but streams of these are now becoming available.For many years, analogue sensors across roads and camera coverage of different places have generated some sampling of traffic data streams on a routine basis, but now individual sensors in cars, at fixed locations, and in mobile devices are dramatically increasing the flow of such data.A good example is from electronic ticketing systems such as automated subway data streams that we have used to process travel flow data on the London Underground (Roth et al, 2009).However more generic data streams now exist.Twitter is a system of short text messaging that is now widely popular as a medium for instant communication of every kind of information and data and, as such, it is rapidly becoming a measure of generic communication, notwithstanding its idiosyncratic origins.If the user switches on the
DOI: 10.1068/b3704ed
Author: Michael Batty
Language: English
Subfield: Transportation
Field: Social Sciences
Domain: Social Sciences
Open Access status: bronze
OpenAlex ID: W2062092090