# Diederik Aerts

Diederik Aerts (born April 17, 1953) is a Belgian theoretical physicist and a professor at Brussels Free University (Vrije Universiteit Brussel - VUB), where he directs the Center Leo Apostel for Interdisciplinary Studies (CLEA).

## Quotes

* Poincaré analyses how the reality of three dimensional Euclidean (or non-Euclidean) space, has been constructed from our daily experiences as a human being with the objects that are most important for us (rigid bodies), and closely around. This does not mean that this three dimensional space is an ‘invention’ of humanity. It exists, but the way we have ordered, and later on formalized it, by means of specific mathematical models, does make part of it. In other words, what we call the three dimensional reality of space partly exists in its own and partly exists by the structures that we have constructed, relying on our specific human experience with it.
** Aerts, "An attempt to imagine parts of the reality of the micro-world," in Problems in Quantum Physics II; Gdansk ’89, eds. Mizerski, J., et al., World Scientific Publishing Company, Singapore, 1990. pp. 3–25
* In classical Newtonian physics there was a clear understanding of 'what reality is'. Indeed in this classical view, reality at a certain time is the collection of all what is actual at this time, and this is contained in 'the present'. Often it is stated that three dimensional space and one dimensional time have been substituted by four dimensional space-time in relativity theory, and as a consequence the classical concept of reality, as that what is 'present', cannot be retained. Is reality then the four dimensional manifold of relativity theory? And if so, what is then the meaning of 'change in time'?
** Aerts, D. (1996). "Relativity theory: what is reality?". Foundations of Physics, 26, pp. 1627-1644
* The classical concept of 'physical entity', be it particle, wave, field or system, has become a problematic concept since the advent of relativity theory and quantum mechanics. The recent developments in modern quantum mechanics, with the performance of delicate and precise experiments involving single quantum entities, manifesting explicit non-local behavior for these entities, brings essential new information about the nature of the concept of entity.
** Aerts, D. (1998). "The entity and modern physics: the creation-discovery view of reality." In E. Castellani (Ed.), Interpreting Bodies: Classical and Quantum Objects in Modern Physics (pp. 223-257). Princeton: Princeton University Press.
* What is reality? What is space? And what is time? These are the three questions that we want to investigate taking into account the knowledge that we have gained by modern physics. Our intuitive prescientific conception of the world in relation with these three concepts is not very precise but could be summarised as follows. - Reality is everything that exists now in the present. The past has been real but is not anymore and the future is what shall become real but is not yet. - Space is the theatre where reality is in. It englobes all of reality. Till the birth of relativity theory all physical theories where compatible with this intuitive scheme. But when relativity theory entered the scene, these intuitive conceptions of space and time, and what is less recognised even till today, also the conception of reality, has got into problems.
** Diederik Aerts (2001) "Time, space and reality : an analysis from physics."

### World views. From Fragmentation to Integration (1994)

    Diederic Aerts, Leo Apostel, Bart De Moor, Staff Hellemans, Edel Maex, Hubert Van Belle & Jan Van der Veken (1994) World views. From Fragmentation to Integration. Vrije Universiteit Brussel, VUB Press.
* The world around us can be construed as a huge "house" that we share with other humans, as well as with animals and plants. It is in this world that we exist, fulfilling our tasks, enjoying things, developing social relations, creating a family. In short, we live in this world. We thus have a deep human need to know and to trust it, to be emotionally involved in it. Many of us, however, experience an increasing feeling of alienation. Even though, with the expansion of society, virtually the entire surface of the planet has become a part of our house, often we do not feel "at home" in that house. With the rapid and spontaneous changes of the past decades, so many new wings and rooms have been constructed or rearranged that we have lost familiarity with our house. We often have the impression that what remains of the world is a collection of isolated fragments, without any structure and coherence. Our personal "everyday" world seems unable to harmonise itself with the global world of society, history and cosmos. It is our conviction that the time has come to make a conscious effort towards the construction of global world views, in order to overcome this situation of fragmentation. There are many reasons why we believe in the benefit of such an enterprise, and in the following pages we shall attempt to make some of them clear.
** p. 1; About "The fragmentation of our world"
* World views, as related to the sciences, ethics, arts, politics and religions, are integral parts of all cultures. They have a strongly motivating and inspiring function. A socially shared view of the whole gives a culture a sense of direction, confidence and self-esteem. Moreover, interactions between cultures change constantly.
** p. 8
* A world view is a coherent collection of concepts and theorems that must allow us to construct a global image of the world, and in this way to understand as many elements of our experience as possible. Societies, as well as individuals, have always contemplated deep questions relating to their being and becoming, and to the being and becoming of the world. The configuration of answers to these questions forms their world view. Research on world views, although we are convinced of its practical value and necessity, will always be primarily an expression of a theoretical interest. It reflects the unlimited openness of the human mind to reality as a whole. Even if this research would not appear to be of any immediate value or necessity – quod non – we still should promote and encourage it energetically, because it also expresses the most unselfish striving of humanity “the desire to know,” a property of “Homo sapiens sapiens.”
** p. 8
* A world view is a system of co-ordinates or a frame of reference in which everything presented to us by our diverse experiences can be placed. It is a symbolic system of representation that allows us to integrate everything we know about the world and ourselves into a global picture, one that illuminates reality as it is presented to us within a certain culture.
** p. 8

### Perspectives on the World: an interdisciplinary reflection. (1995)

    Diederic Aerts, Leo Apostel, Bart De Moor, Staff Hellemans, Edel Maex, Hubert Van Belle & Jan Van der Veken (1995) Perspectives on the World: an interdisciplinary reflection. VUB Press, Brussels.
* We are quickly approaching the end of the millennium and the 'magical' year 2000. Many futurologists in the sixties thought science and technolo­gy would offer man unprecedented possibilities for solving his problems. The fall of the Iron Curtain and the implosion of the Eastern Block also created, just a, few years ago, grand expectations. The dream did not come true, however. Rather than ending up in a technological paradise and a peace-loving world, we woke up in a torn world with virtually unsolvable environmental problems and agonising social conditions.
** p. i : Introduction
* Although world views grow organic ly and historically, they can also be developed. The construction of world views is comparable to the work of cartographers in antiquity and in the Middle Ages. They mapped out the world on the basis of information from sailors, mer­ chants and explorers.
** p. iv
* We continually speak of world views in the plural because a unique and monolithic world view - considering the immense complexity of reality - will remain an unattainable ideal.
** p. iv
* In the construction of world views one can distinguish seven important tasks that correspond with the various components of a world view and that must provide an answer to a number of fundamental questions. First we must design a model of the world. What is the world like in which we live? How is the world structured and how does it function? What are the most suitable metaphors for speaking of the whole? Are mechanistic or organic models to be given preference? An explanation of reality must then follow. Why are the world and mankind as they are? Is a completely different world possible? What general explanatory principles apply?
** p. v : About "The seven tasks of World-view construction"

### Quantum structure in cognition, 2009

Aerts, Diederik. "Quantum structure in cognition." Journal of Mathematical Psychology 53.5 (2009): 314-348.
* The broader scope of our investigations is the search for the way in which concepts and their combinations carry and influence meaning and what this implies for human thought. More specifically, we examine the use of the mathematical formalism of quantum mechanics as a modeling instrument and propose a general mathematical modeling scheme for the combinations of concepts.
** p. 314 ; Opening line of abstract about scope of the work presented
* We have come to suspect that `the way concepts combine and how they carry and communicate meaning' is governed by the presence of quantum structure in cognition.
** p. 315
* In our study of applying quantum to cognition we have identified five main aspects that play a fundamental role and that are specific to quantum structures as compared to classical structures. They are (i) contextual in influence (ii) emergence due to superposition, (iii) interference, (iv) entanglement and (v) quantum field theoretic aspects.
** p. 317

## Quotes about Diederik Aerts

* From the beginning of his research, the Belgian physicist Diederik Aerts has shown great creativity in inventing a number of concrete machine-models that have played an important role in the development of general mathematical and conceptual formalisms for the description of the physical reality.
** Massimiliano Sassoli de Bianchi (2013) "Using simple elastic bands to explain quantum mechanics: a conceptual review of two of Aerts' machine-models." Central European Journal of Physics, Volume 11, Issue 2, pp 147-161.

## External links

* Homepage at Brussels Free University