




Philosophy of space


Galilean and Cartesian theories about space, matter, and motion are at the foundation of the Scientific Revolution, which is understood to have culminated with the publication of Newton's Principia in 1687.[5] Newton's theories about space and time helped him explain the movement of objects. While his theory of space is considered the most influential in Physics, it emerged from his predecessors' ideas about the same.[6]

As one of the pioneers of modern science, Galileo revised the established Aristotelian and Ptolemaic ideas about a geocentric cosmos. He backed the Copernican theory that the universe was heliocentric, with a stationary sun at the center and the planets—including the Earth—revolving around the sun. If the Earth moved, the Aristotelian belief that its natural tendency was to remain at rest was in question. Galileo wanted to prove instead that the sun moved around its axis, that motion was as natural to an object as the state of rest. In other words, for Galileo, celestial bodies, including the Earth, were naturally inclined to move in circles. This view displaced another Aristotelian idea—that all objects gravitated towards their designated natural place-of-belonging.[7]

René Descartes

Descartes set out to replace the Aristotelian worldview with a theory about space and motion as determined by natural laws. In other words, he sought a metaphysical foundation or a mechanical explanation for his theories about matter and motion. Cartesian space was Euclidean in structure—infinite, uniform and flat.[8] It was defined as that which contained matter; conversely, matter by definition had a spatial extension so that there was no such thing as empty space.[5]

The Cartesian notion of space is closely linked to his theories about the nature of the body, mind and matter. He is famously known for his "cogito ergo sum" (I think therefore I am), or the idea that we can only be certain of the fact that we can doubt, and therefore think and therefore exist. His theories belong to the rationalist tradition, which attributes knowledge about the world to our ability to think rather than to our experiences, as the empiricists believe.[9] He posited a clear distinction between the body and mind, which is referred to as the Cartesian dualism.

Leibniz and Newton

Gottfried Leibniz

Following Galileo and Descartes, during the seventeenth century the philosophy of space and time revolved around the ideas of Gottfried Leibniz, a German philosopher–mathematician, and Isaac Newton, who set out two opposing theories of what space is. Rather than being an entity that independently exists over and above other matter, Leibniz held that space is no more than the collection of spatial relations between objects in the world: "space is that which results from places taken together".[10] Unoccupied regions are those that could have objects in them, and thus spatial relations with other places. For Leibniz, then, space was an idealised abstraction from the relations between individual entities or their possible locations and therefore could not be continuous but must be discrete.[11] Space could be thought of in a similar way to the relations between family members. Although people in the family are related to one another, the relations do not exist independently of the people.[12] Leibniz argued that space could not exist independently of objects in the world because that implies a difference between two universes exactly alike except for the location of the material world in each universe. But since there would be no observational way of telling these universes apart then, according to the identity of indiscernibles, there would be no real difference between them. According to the principle of sufficient reason, any theory of space that implied that there could be these two possible universes must therefore be wrong.[13]



In the eighteenth century the German philosopher Immanuel Kant developed a theory of knowledge in which knowledge about space can be both a priori and synthetic.[16] According to Kant, knowledge about space is synthetic, in that statements about space are not simply true by virtue of the meaning of the words in the statement. In his work, Kant rejected the view that space must be either a substance or relation. Instead he came to the conclusion that space and time are not discovered by humans to be objective features of the world, but imposed by us as part of a framework for organizing experience.[17]

Non-Euclidean geometry



Type of geometryNumber of parallelsSum of angles in a triangleRatio of circumference to diameter of circleMeasure of curvature
Hyperbolic Infinite< 180°> π< 0
Euclidean 1180°π0
Elliptical 0> 180°< π> 0

Gauss and Poincaré


Henri Poincaré, a French mathematician and physicist of the late 19th century, introduced an important insight in which he attempted to demonstrate the futility of any attempt to discover which geometry applies to space by experiment.[20] He considered the predicament that would face scientists if they were confined to the surface of an imaginary large sphere with particular properties, known as a sphere-world. In this world, the temperature is taken to vary in such a way that all objects expand and contract in similar proportions in different places on the sphere. With a suitable falloff in temperature, if the scientists try to use measuring rods to determine the sum of the angles in a triangle, they can be deceived into thinking that they inhabit a plane, rather than a spherical surface.[21] In fact, the scientists cannot in principle determine whether they inhabit a plane or sphere and, Poincaré argued, the same is true for the debate over whether real space is Euclidean or not. For him, which geometry was used to describe space was a matter of convention.[22] Since Euclidean geometry is simpler than non-Euclidean geometry, he assumed the former would always be used to describe the 'true' geometry of the world.[23]



Subsequently, Einstein worked on a general theory of relativity, which is a theory of how gravity interacts with spacetime. Instead of viewing gravity as a force field acting in spacetime, Einstein suggested that it modifies the geometric structure of spacetime itself.[24] According to the general theory, time goes more slowly at places with lower gravitational potentials and rays of light bend in the presence of a gravitational field. Scientists have studied the behaviour of binary pulsars, confirming the predictions of Einstein's theories, and non-Euclidean geometry is usually used to describe spacetime.





Today, our three-dimensional space is viewed as embedded in a four-dimensional spacetime, called Minkowski space (see special relativity). The idea behind space-time is that time is hyperbolic-orthogonal to each of the three spatial dimensions.


Before Albert Einstein's work on relativistic physics, time and space were viewed as independent dimensions. Einstein's discoveries showed that due to relativity of motion our space and time can be mathematically combined into one object–spacetime. It turns out that distances in space or in time separately are not invariant with respect to Lorentz coordinate transformations, but distances in Minkowski space-time along space-time intervals are—which justifies the name.


Furthermore, in Einstein's general theory of relativity, it is postulated that space-time is geometrically distorted – curved – near to gravitationally significant masses.[25]

One consequence of this postulate, which follows from the equations of general relativity, is the prediction of moving ripples of space-time, called gravitational waves. While indirect evidence for these waves has been found (in the motions of the Hulse–Taylor binary system, for example) experiments attempting to directly measure these waves are ongoing at the LIGO and Virgo collaborations. LIGO scientists reported the first such direct observation of gravitational waves on 14 September 2015.[26][27]


Relativity theory leads to the cosmological question of what shape the universe is, and where space came from. It appears that space was created in the Big Bang, 13.8 billion years ago[28] and has been expanding ever since. The overall shape of space is not known, but space is known to be expanding very rapidly due to the cosmic inflation.

Spatial measurement



Geographical space

Geography is the branch of science concerned with identifying and describing places on Earth, utilizing spatial awareness to try to understand why things exist in specific locations. Cartography is the mapping of spaces to allow better navigation, for visualization purposes and to act as a locational device. Geostatistics apply statistical concepts to collected spatial data of Earth to create an estimate for unobserved phenomena.





In psychology





In the social sciences

Space has been studied in the social sciences from the perspectives of Marxism, feminism, postmodernism, postcolonialism, urban theory and critical geography. These theories account for the effect of the history of colonialism, transatlantic slavery and globalization on our understanding and experience of space and place. The topic has garnered attention since the 1980s, after the publication of Henri Lefebvre's The Production of Space . In this book, Lefebvre applies Marxist ideas about the production of commodities and accumulation of capital to discuss space as a social product. His focus is on the multiple and overlapping social processes that produce space.[29]

In his book The Condition of Postmodernity, David Harvey describes what he terms the "time-space compression." This is the effect of technological advances and capitalism on our perception of time, space and distance.[30] Changes in the modes of production and consumption of capital affect and are affected by developments in transportation and technology. These advances create relationships across time and space, new markets and groups of wealthy elites in urban centers, all of which annihilate distances and affect our perception of linearity and distance.[31]

In his book Thirdspace, Edward Soja describes space and spatiality as an integral and neglected aspect of what he calls the "trialectics of being," the three modes that determine how we inhabit, experience and understand the world. He argues that critical theories in the Humanities and Social Sciences study the historical and social dimensions of our lived experience, neglecting the spatial dimension.[32] He builds on Henri Lefebvre's work to address the dualistic way in which humans understand space—as either material/physical or as represented/imagined. Lefebvre's "lived space"[33] and Soja's "thridspace" are terms that account for the complex ways in which humans understand and navigate place, which "firstspace" and "Secondspace" (Soja's terms for material and imagined spaces respectively) do not fully encompass.

Postcolonial theorist Homi Bhabha's concept of Third Space is different from Soja's Thirdspace, even though both terms offer a way to think outside the terms of a binary logic. Bhabha's Third Space is the space in which hybrid cultural forms and identities exist. In his theories, the term hybrid describes new cultural forms that emerge through the interaction between colonizer and colonized.[34]

See also


  1. "Space – Physics and Metaphysics". Encyclopædia Britannica. Archived from the original on 6 May 2008. Retrieved 28 April 2008.
  3. French, A.J.; Ebison, M.G. (1986). Introduction to Classical Mechanics. Dordrecht: Springer, p. 1.
  4. Carnap, R. (1995). An Introduction to the Philosophy of Science. New York: Dove. (Original edition: Philosophical Foundations of Physics. New York: Basic books, 1966).
  5. Space from Zeno to Einstein : classic readings with a contemporary commentary. Huggett, Nick. Cambridge, Mass.: MIT Press. 1999. ISBN 978-0-585-05570-1. OCLC 42855123.CS1 maint: others (link)
  6. Janiak, Andrew (2015). "Space and Motion in Nature and Scripture: Galileo, Descartes, Newton". Studies in History and Philosophy of Science. 51: 89–99. doi:10.1016/j.shpsa.2015.02.004. PMID 26227236.
  7. 1958–, Dainton, Barry (2001). Time and space. Montreal: McGill-Queen's University Press. ISBN 978-0-7735-2302-9. OCLC 47691120.CS1 maint: numeric names: authors list (link)
  8. Dainton, Barry (2014). Time and Space. McGill-Queen's University Press. p. 164.
  9. Tom., Sorell (2000). Descartes : a very short introduction. Oxford: Oxford University Press. ISBN 978-0-19-154036-3. OCLC 428970574.
  10. Leibniz, Fifth letter to Samuel Clarke. By H.G. Alexander (1956). The Leibniz-Clarke Correspondence. Manchester: Manchester University Press, pp. 55–96.
  11. Vailati, E. (1997). Leibniz & Clarke: A Study of Their Correspondence. New York: Oxford University Press, p. 115.
  12. Sklar, L. (1992). Philosophy of Physics. Boulder: Westview Press, p. 20.
  13. Sklar, L. Philosophy of Physics. p. 21.
  14. Sklar, L. Philosophy of Physics. p. 22.
  15. "Newton's bucket". Archived from the original on 17 March 2008. Retrieved 20 July 2008.
  16. Carnap, R. An Introduction to the Philosophy of Science. pp. 177–178.
  17. Lucas, John Randolph (1984). Space, Time and Causality. p. 149. ISBN 978-0-19-875057-4.
  18. Carnap, R. An Introduction to the Philosophy of Science. p. 126.
  19. Carnap, R. An Introduction to the Philosophy of Science. pp. 134–136.
  20. Jammer, Max (1954). Concepts of Space. The History of Theories of Space in Physics. Cambridge: Harvard University Press, p. 165.
  22. Carnap, R. An Introduction to the Philosophy of Science. p. 148.
  23. Sklar, L. Philosophy of Physics. p. 57.
  24. Sklar, L. Philosophy of Physics. p. 43.
  25. Wheeler, John A. A Journey into Gravity and Spacetime. Chapters 8 and 9, Scientific American, ISBN 0-7167-6034-7
  26. Castelvecchi, Davide; Witze, Alexandra (11 February 2016). "Einstein's gravitational waves found at last". Nature News. Archived from the original on 16 February 2016. Retrieved 12 January 2018.
  28. "Cosmic Detectives". The European Space Agency (ESA). 2 April 2013. Archived from the original on 5 April 2013. Retrieved 26 April 2013.
  29. Stanek, Lukasz (2011). Henri Lefebvre on Space : Architecture, Urban Research, and the Production of Theory. Univ of Minnesota Press. pp. ix.
  30. "Time-Space Compression – Geography – Oxford Bibliographies – obo". Archived from the original on 20 September 2018. Retrieved 28 August 2018.
  31. Harvey, David (2001). Spaces of Capital : Towards a Critical Geography. Edinburgh University Press. pp. 244–246.
  32. W., Soja, Edward (1996). Thirdspace : journeys to Los Angeles and other real-and-imagined places. Cambridge, Mass.: Blackwell. ISBN 978-1-55786-674-5. OCLC 33863376.
  33. 1901–1991., Lefebvre, Henri (1991). The production of space. Oxford, OX, UK: Blackwell. ISBN 978-0-631-14048-1. OCLC 22624721.CS1 maint: numeric names: authors list (link)
  34. 1946–, Ashcroft, Bill (2013). Postcolonial studies : the key concepts. Griffiths, Gareth, 1943–, Tiffin, Helen., Ashcroft, Bill, 1946– (Third ed.). London. ISBN 978-0-415-66190-4. OCLC 824119565.CS1 maint: numeric names: authors list (link)