224 research outputs found
The concept of free will as an infinite metatheoretic recursion
It is argued that the concept of free will, like the concept of truth in
formal languages, requires a separation between an object level and a
meta-level for being consistently defined. The Jamesian two-stage model, which
deconstructs free will into the causally open "free" stage with its closure in
the "will" stage, is implicitly a move in this direction. However, to avoid the
dilemma of determinism, free will additionally requires an infinite regress of
causal meta-stages, making free choice a hypertask. We use this model to define
free will of the rationalist-compatibilist type. This is shown to provide a
natural three-way distinction between quantum indeterminism, freedom and free
will, applicable respectively to artificial intelligence (AI), animal agents
and human agents. We propose that the causal hierarchy in our model corresponds
to a hierarchy of Turing uncomputability. Possible neurobiological and
behavioral tests to demonstrate free will experimentally are suggested.
Ramifications of the model for physics, evolutionary biology, neuroscience,
neuropathological medicine and moral philosophy are briefly outlined.Comment: Accepted in INDECS (close to the accepted version
Causality - Complexity - Consistency: Can Space-Time Be Based on Logic and Computation?
The difficulty of explaining non-local correlations in a fixed causal
structure sheds new light on the old debate on whether space and time are to be
seen as fundamental. Refraining from assuming space-time as given a priori has
a number of consequences. First, the usual definitions of randomness depend on
a causal structure and turn meaningless. So motivated, we propose an intrinsic,
physically motivated measure for the randomness of a string of bits: its length
minus its normalized work value, a quantity we closely relate to its Kolmogorov
complexity (the length of the shortest program making a universal Turing
machine output this string). We test this alternative concept of randomness for
the example of non-local correlations, and we end up with a reasoning that
leads to similar conclusions as in, but is conceptually more direct than, the
probabilistic view since only the outcomes of measurements that can actually
all be carried out together are put into relation to each other. In the same
context-free spirit, we connect the logical reversibility of an evolution to
the second law of thermodynamics and the arrow of time. Refining this, we end
up with a speculation on the emergence of a space-time structure on bit strings
in terms of data-compressibility relations. Finally, we show that logical
consistency, by which we replace the abandoned causality, it strictly weaker a
constraint than the latter in the multi-party case.Comment: 17 pages, 16 figures, small correction
Collective Motion of Predictive Swarms
Theoretical models of populations and swarms typically start with the
assumption that the motion of agents is governed by the local stimuli. However,
an intelligent agent, with some understanding of the laws that govern its
habitat, can anticipate the future, and make predictions to gather resources
more efficiently. Here we study a specific model of this kind, where agents aim
to maximize their consumption of a diffusing resource, by attempting to predict
the future of a resource field and the actions of other agents. Once the agents
make a prediction, they are attracted to move towards regions that have, and
will have, denser resources. We find that the further the agents attempt to see
into the future, the more their attempts at prediction fail, and the less
resources they consume. We also study the case where predictive agents compete
against non-predictive agents and find the predictors perform better than the
non-predictors only when their relative numbers are very small. We conclude
that predictivity pays off either when the predictors do not see too far into
the future or the number of predictors is small.Comment: 16 pages, 7 figure
Quantum randomness and value indefiniteness
As computability implies value definiteness, certain sequences of quantum
outcomes cannot be computable.Comment: 13 pages, revise
The quantum measurement problem and physical reality: a computation theoretic perspective
Is the universe computable? If yes, is it computationally a polynomial place?
In standard quantum mechanics, which permits infinite parallelism and the
infinitely precise specification of states, a negative answer to both questions
is not ruled out. On the other hand, empirical evidence suggests that
NP-complete problems are intractable in the physical world. Likewise,
computational problems known to be algorithmically uncomputable do not seem to
be computable by any physical means. We suggest that this close correspondence
between the efficiency and power of abstract algorithms on the one hand, and
physical computers on the other, finds a natural explanation if the universe is
assumed to be algorithmic; that is, that physical reality is the product of
discrete sub-physical information processing equivalent to the actions of a
probabilistic Turing machine. This assumption can be reconciled with the
observed exponentiality of quantum systems at microscopic scales, and the
consequent possibility of implementing Shor's quantum polynomial time algorithm
at that scale, provided the degree of superposition is intrinsically, finitely
upper-bounded. If this bound is associated with the quantum-classical divide
(the Heisenberg cut), a natural resolution to the quantum measurement problem
arises. From this viewpoint, macroscopic classicality is an evidence that the
universe is in BPP, and both questions raised above receive affirmative
answers. A recently proposed computational model of quantum measurement, which
relates the Heisenberg cut to the discreteness of Hilbert space, is briefly
discussed. A connection to quantum gravity is noted. Our results are compatible
with the philosophy that mathematical truths are independent of the laws of
physics.Comment: Talk presented at "Quantum Computing: Back Action 2006", IIT Kanpur,
India, March 200
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