ABSTRACT
Tobler’s ‘law’ that distance underpins spatial interaction has been a fundamental construct of theoretical geography since the quantitative revolution in the 1950s and 1960s. The gravity model is its most common manifestation. The greatest challenge to this ‘law’ came with the advent of the internet, where distant things became very near things because information packets could be transferred at speeds approaching the velocity of light. The ‘death of distance’ hypothesis became the vogue for a short while, until Baker (2005) showed that the gravity model is still relevant, because the rate of information transfer is not infinite, but is limited by the speed of light. Why is physics (again) important to spatial interaction at a geographical scale? An answer is that current telecommunications, GPS determinations, weapon systems and mobile phone networks depend on a very rapid connectivity of a plethora of electronic information, predicated on infinitesimal space and time co-ordinates. The speeds of transmission of information from these origins to destinations are now within the range of the speed of light, hence the juxtaposition between geography and physics. The maxim, however, is still that ‘distance always matters’ and is very relevant today, despite the technological revolution.
