arXiv subjects

Mark J Hadley

Publications and source records attributed to Mark J Hadley.

11 recordsLinked to original sources

arXiv2018

Free Will and Physics

The abstract concept of indeterministic free will is distinguished from the phenomenon of free will. Evidence for the abstract concept is examined and critically compared with various designs of automata. It is concluded that there is no evidence to support the abstract concept of indeterministic free will, it is inconceivable that a test could be constructed to distinguish an indeterministic agent from a complicated automaton. Testing the free will of an alien visitor is introduced to separate prejudices about who has free will from objective experiments. The phenomenon of free will is modelled with a deterministic decision making agent. The agent values independence and satisfies a desire for independence by responding to challenges. When the agent generates challenges internally it will establish a record of being able to do otherwise. In principle a computer could be built with a free will property. The model also explains false attributions of free will (superstitions).

physics.gen-ph↗

arXiv2011

The asymmetric Kerr metric as a source of CP violation

All experimental evidence for violation of discrete spacetime symmetries: Parity and Time reversal and the related Charge conjugation/Parity combination (P, T and CP respectively) has been obtained on earth in a gravitational potential that is P and T anisotropic. It is suggested that the origin of the observed CP violation is the scalar field equal to the frame dragging term $dϕdt$ in the Kerr metric of a spinning massive body. The galaxy would be the largest such source. Indirect evidence of such an effect would be anisotropic decay products when plotted in a reference frame defined by the fixed stars. As a consequence, CP violation would be very much greater near compact astrophysical objects with large angular momentum.

gr-qc↗

arXiv2008

Quantum fields as gravitational sources

The practice of setting quantum fields as sources for classical general relativity is examined. Several conceptual problems are identified which invalidate apparently innocuous equations. Alternative ways to links classical general relativity with quantum theory using Bohm's theory are proposed.

physics.gen-ph↗

arXiv2007

A gravitational explanation for quantum theory - non-time-orientable manifolds

Spacetime manifolds that are not time orientable play a key role in a gravitational explanation of quantum theory. Such manifolds allow topology change, but also have fascinating additional properties such as net charge from source-free equations and spin half transformation properties. It is shown how the logical structure of propositions and the probabilities of quantum theory arise from such acausal space times

gr-qc↗

arXiv2007

Classical Dark Matter

Classical particle-like solutions of field equations such as general relativity, could account for dark matter. Such particles would not interact quantum mechanically and would have negligible interactions apart from gravitation. As a relic from the big bang, they would be a candidate for cold dark matter consistent with observations.

gr-qc↗

arXiv2006

Time machines and quantum theory

There is a deep structural link between acausal spacetimes and quantum theory. As a consequence quantum theory may resolve some "paradoxes" of time travel. Conversely, non-time-orientable spacetimes naturally give rise to electric charges and spin half. If an explanation of quantum theory is possible, then general relativity with time travel could be it.

gr-qc↗

arXiv2006

Geometric models of particles - the missing ingredient

Einstein's dream of describing elementary particles as solutions of a classical field theory is severely limited by our current understanding of Nature. Quantum theory is inconsistent with any local realistic theory such as evolving topological structures in space. It is shown that allowing time reversal as an intrinsic part of the structure of elementary particles allows general relativity to explain quantum theory in principle. Such structures may also explain electric charge and spin-half.

physics.gen-ph↗

arXiv2004

A conserved Parity Operator

The symmetry of Nature under a Space Inversion is described by a Parity operator. Contrary to popular belief, the Parity operator is not unique. The choice of the Parity operator requires several arbitrary decisions to be made. It is shown that alternative, equally plausible, choices leads to the definition of a Parity operator that is conserved by the Weak Interactions. The operator commonly known as CP is a more appropriate choice for a Parity operator.

physics.gen-ph↗

arXiv2002

The orientability of spacetime

Contrary to established beliefs, spacetime may not be time-orientable. By considering an experimental test of time orientability it is shown that a failure of time-orientability of a spacetime region would be indistinguishable from a particle antiparticle annihilation event.

gr-qc↗

arXiv1999

Charge and the topology of spacetime

A new class of electrically charged wormholes is described in which the outer two sphere is not spanned by a compact coorientable hypersurface. These wormholes can therefore display net electric charge from the source free Maxwell's equation. This extends the work of Sorkin on non-space orientable manifolds, to spacetimes which do not admit a time orientation. The work is motivated by the suggestion that quantum theory can be explained by modelling elementary particles as regions of spacetime with non-trivial causal structure. The simplest example of an electrically charged spacetime carries a spherical symmetry.

gr-qc↗

arXiv1999

Topology change and context dependence

The non-classical features of quantum mechanics are reproduced using models constructed with a classical theory - general relativity. The inability to define complete initial data consistently and independently of future measurements, non-locality, and the non-Boolean logical structure are reproduced by these examples. The key feature of the models is the role of topology change. It is the breakdown of causal structure associated with topology change that leads to the apparently non-classical behaviour. For geons, topology change is required to describe the interaction of particles. It is therefore natural to regard topology change as an essential part of the measurement process. This leads to models in which the measurement imposes additional non-redundant boundary conditions. The initial state cannot be described independently of the measurement and there is a causal connection between the measurement and the initial state.

gr-qc↗