144,097 research outputs found
String Theory - From Physics to Metaphysics
Currently, string theory represents the only advanced approach to a
unification of all interactions, including gravity. In spite of the more than
thirty years of its existence it did not make any empirically testable
predictions. And it is completely unknown which physically interpretable
principles could form the basis of string theory. At the moment, "string
theory" is no theory at all, but rather a labyrinthic structure of mathematical
procedures and intuitions which get their justification from the fact that
they, at least formally, reproduce general relativity and the standard model of
elementary particle physics as low energy approximations. However, there are
now strong indications that string theory does not only reproduce the dynamics
and symmetries of our standard model, but a plethora of different scenarios
with different low energy nomologies and symmetries. String theory seems to
describe not only our world, but an immense landscape of possible worlds. So
far, all attempts to find a selection principle which could be motivated
intratheoretically remained without success. So, recently the idea that the low
energy nomology of our world, and therefore also the observable phenomenology,
could be the result of an anthropic selection from a vast arena of
nomologically different scenarios entered string theory. Although multiverse
scenarios and anthropic selection are not only motivated by string theory, but
lead also to a possible explanation for the fine tuning of the universe, they
are concepts which transcend the framework defined by the epistemological and
methodological rules which conventionally form the basis of physics as an
empirical science.Comment: 30 pages, submitted to "Physics and Philosophy" (Online-Journal
Engels’ Intentions in Dialectics of Nature
Reading different or controversial intentions into Marx
and Engels’ works has been somewhat a common but rather
unquestioned practice in the history of Marxist scholarship. Engels’
Dialectics of Nature, a torso for some and a great book for others, is a
case in point. A bold line seems to shape the entire Engels debate and
separate two opposite views in this regard: Engels the contaminator of
Marx’s materialism vs. Engels the self-started genius of dialectical
materialism. What Engels, unlike Marx, has not enjoyed so far is a
critical reflection upon the relationship between different layers of this
text: authorial, textual, editorial and interpretational. Informed by a
historical hermeneutic, inquiry into the elements that structure the
debate on “Dialectics of Nature,” and into the different political and
philosophical functions attached to it, makes it possible to relocate the
meaning of “dialectics” in a more precise context. Engels’ dialectics is
less complete than we usually think it is, but he achieved more than
most scholars would like to admit
Particle Physics-Future Directions
Wonderful opportunities await particle physics over the next decade, with the
coming of the Large Hadron Collider at CERN to explore the 1-TeV scale
(extending efforts at LEP and the Tevatron to unravel the nature of electroweak
symmetry breaking) and many initiatives to develop our understanding of the
problem of identity: what makes a neutrino a neutrino and a top quark a top
quark. Here I have in mind the work of the B factories and the Tevatron
collider on CP violation and the weak interactions of the b quark; the
wonderfully sensitive experiments at Brookhaven, CERN, Fermilab, and Frascati
on CP violation and rare decays of kaons; the prospect of definitive
accelerator experiments on neutrino oscillations and the nature of the
neutrinos; and a host of new experiments on the sensitivity frontier. We might
even learn to read experiment for clues about the dimensionality of spacetime.
If we are inventive enough, we may be able to follow this rich menu with the
physics opportunities offered by a linear collider and a (muon storage ring)
neutrino factory. I expect a remarkable flowering of experimental particle
physics, and of theoretical physics that engages with experiment. I describe
some of the great questions before us and the challenges of providing the
instruments that will be needed to define them more fully and-eventually-to
answer them.Comment: Invited paper at the 2001 Particle Accelerator Conference, Chicago; 5
pages; uses JAC2001.cls (included
Principles for Consciousness in Integrated Cognitive Control
In this article we will argue that given certain conditions for the evolution of bi- \ud
ological controllers, these will necessarily evolve in the direction of incorporating \ud
consciousness capabilities. We will also see what are the necessary mechanics for \ud
the provision of these capabilities and extrapolate this vision to the world of artifi- \ud
cial systems postulating seven design principles for conscious systems. This article \ud
was published in the journal Neural Networks special issue on brain and conscious- \ud
ness
The role of falsification in the development of cognitive architectures: insights from a Lakatosian analysis
It has been suggested that the enterprise of developing mechanistic theories of the human cognitive architecture is flawed because the theories produced are not directly falsifiable. Newell attempted to sidestep this criticism by arguing for a Lakatosian model of scientific progress in which cognitive architectures should be understood as theories that develop over time. However, Newell’s own candidate cognitive architecture adhered only loosely to Lakatosian principles. This paper reconsiders the role of falsification and the potential utility of Lakatosian principles in the development of cognitive architectures. It is argued that a lack of direct falsifiability need not undermine the scientific development of a cognitive architecture if broadly Lakatosian principles are adopted. Moreover, it is demonstrated that the Lakatosian concepts of positive and negative heuristics for theory development and of general heuristic power offer methods for guiding the development of an architecture and for evaluating the contribution and potential of an architecture’s research program
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