47,355 research outputs found
Determinism and Causation Examples
In studying causation, many examples are presented assuming that determinism holds in the world of the example such as the notoriously difficult to resolve preemptive and preventative situations. We show that for deterministic examples that this conditional preemptive situation is either (i)vacuously true, (ii)contradictory, or (iii) implies indeterminism. Along the way we formulate a specific block space-time definition of determinism, and suggest that commonsense causation theories need focus on unphysical quantities and indeterminism
Bell's theorem and the issue of determinism and indeterminism
The paper considers the claim that quantum theories with a deterministic
dynamics of objects in ordinary space-time, such as Bohmian mechanics,
contradict the assumption that the measurement settings can be freely chosen in
the EPR experiment. That assumption is one of the premises of Bell's theorem. I
first argue that only a premise to the effect that what determines the choice
of the measurement settings is independent of what determines the past state of
the measured system is needed for the derivation of Bell's theorem. Determinism
as such does not undermine that independence (unless there are particular
initial conditions of the universe that would amount to conspiracy). Only
entanglement could do so. However, generic entanglement without collapse on the
level of the universal wave function can go together with effective wave
functions for subsystems of the universe, as in Bohmian mechanics. The paper
argues that such effective wave functions are sufficient for the mentioned
independence premise to hold
Is Time Travel Too Strange to Be Possible? Determinism and Indeterminism on Closed Timelike Curves
Notoriously, the Einstein equations of general relativity have solutions in
which closed timelike curves (CTCs) occur. On these curves time loops back onto
itself, which has exotic consequences. However, in order to make time travel
stories consistent constraints have to be satisfied, which prevents seemingly
ordinary and plausible processes from occurring. This, and several other
"unphysical" features, have motivated many authors to exclude solutions with
CTCs from consideration, e.g. by conjecturing a chronology protection law. In
this contribution we shall investigate the nature of one particular class of
exotic consequences of CTCs, namely those involving unexpected cases of
indeterminism or determinism. Indeterminism arises even against the backdrop of
the usual deterministic physical theories when CTCs do not cross spacelike
hypersurfaces outside of a limited CTC-region (such hypersurfaces fail to be
Cauchy surfaces). By contrast, a certain kind of determinism appears to arise
when an indeterministic theory is applied on a CTC: things cannot be different
from what they already were. We shall argue that on further consideration both
this indeterminism and determinism on CTCs turn out to possess analogues in
other, familiar areas of physics. CTC-indeterminism is close to the
epistemological indeterminism we know from statistical physics, while the
"fixedness" typical of CTC-determinism is pervasive in physics. CTC-determinism
and CTC-indeterminism therefore do not provide incontrovertible grounds for
rejecting CTCs as conceptually inadmissible
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