Friction of distance

Principle of geographic thought
Friction of distance is a core principle of geography that states that movement incurs some form of cost, in the form of physical effort, energy, time, and/or the expenditure of other resources, and that these costs are proportional to the distance traveled. This cost is thus a resistance against movement, analogous (but not directly related) to the effect of friction against movement in classical mechanics. The subsequent preference for minimizing distance and its cost underlies a vast array of geographic patterns from economic agglomeration to wildlife migration, as well as many of the theories and techniques of spatial analysis, such as Tobler's first law of geography, network routing, and cost distance analysis. To a large degree, friction of distance is the primary reason why geography is relevant to many aspects of the world, although its importance (and perhaps the importance of geography) has been decreasing with the development of transportation and communication technologies.

It is not known who first coined the term "friction of distance," but the effect of distance based costs on geographic activity and geographic patterns has been a core element of academic geography since its initial rise in the 19th Century. von Thünen's isolated state model of exurban land use (1826), possibly the earliest geographic theory, directly incorporated the cost of transportation of different agricultural products as one of the determinants for how far from a town each type of goods could be produced profitably. The industrial location theory of Alfred Weber (1909) and the central place theory of Walter Christaller (1933) were also basically optimizations of space to minimize travel costs. By the 1920s, social scientists began to incorporate principles of physics (more precisely, some of its mathematical formalizations), such as gravity, specifically the inverse square law found in Newton's law of universal gravitation. Geographers quickly identified a number of situations in which the interaction between places, whether migration between cities or the distribution of residences willing to patronize a shop, exhibited this distance decay due to the advantages of minimizing distance traveled. Gravity models and other Distance optimization models became widespread during the quantitative revolution of the 1950s and the subsequent rise of spatial analysis. Gerald Carrothers (1956) was one of the first to explicitly use the analogy of "friction" to conceptualize the effect of distance, suggesting that these distance optimizations needed to acknowledge that the effect varies according to localized factors. In the era of geographic information systems, starting in the 1970s, many of the existing proximity models and new algorithms were automated as analysis tools, making them significantly easier to use by a wider set of professionals. These tools have tended to focus on problems that could be solved deterministically, such as buffers, Cost distance analysis, interpolation and network routing. Other problems that apply the friction of distance are much more difficult (i. e., NP hard), such as the traveling salesman problem and cluster analysis, and automated tools to solve them (usually using heuristic algorithms such as k means clustering) are less widely available, or only recently available, in GIS software.

Historically, the friction of distance was very high for most types of movement, making long distance movement and interaction relatively slow and rare (but not non existent). The result was a strongly localized human geography, manifested in aspects as varied as language and economy. One of the most profound effects of the technological advances since 1800, including the railroad, the automobile, and the telephone, has been to drastically reduce the costs of moving people, goods, and information over long distances. This led to widespread diffusion and integration, ultimately resulting in many of the aspects of globalization. The geographic effect of this diminishing friction of distance is called time space convergence or cost space convergence. Of these technologies, telecommunications, especially the Internet, has perhaps had the most profound effect. Although there are still distance based costs of transmitting information, such as the laying of cable and the generation of electromagnetic signal energy (traditionally manifesting in ways such as long distance telephone charges), these are now so small for any meaningful unit of information that they are no longer managed in a distance based form, but are bundled into fixed (not based on distance) service costs. For example, some portion of the fee for mobile telephone service covers the higher costs of long distance service, but the customer does not see it, and thus does not make communication decisions based on distance. The rise of free shipping has similar causes and effects on retail trade. It has been argued that the virtual elimination of the friction of distance in many aspects of society has resulted in the "death of Geography," in which relative location is no longer relevant to many tasks in which it formerly played a crucial role. It is now possible to conduct many interactions over global distances almost as easily as over local distances, including retail trade, business to business services, and some types of remote work. Thus, these services could be theoretically provided from anywhere with equal cost. The COVID 19 pandemic has tested and accelerated many of these trends. Conversely, others have seen a strengthening in the geographic effects of other aspects of life, or perhaps the increasing focus on them as traditional distance based aspects have become less relevant. This includes the lifestyle amenities of a place, such as local natural landscapes or urban nightlife that must be experienced in person (thus requiring physical travel and thus entailing the friction of distance). Also, many people prefer in person interactions that could technically be conducted remotely, such as business meetings, education, tourism, and shopping, which should make distance based effects relevant for the foreseeable future. The contrasting trends of "frictional" and "frictionless" factors have necessitated a more nuanced analysis of geography than the traditional blanket statements of location always mattering, or the recent claims that location does not matter at all.