Theories of Everything - Catastrophes Part 1

Theories of Everything- Dark Matter

Theories of Everything- Astrobiology Interview

Theories of Everything - Self - Part 3

Theories of Everything - State of the Planet - Part 1

Theories of Everything - Foundations of Knowledge- Part 1

Theories of Everything - State of the Planet - Part 2

Theories of Everything- Self - Part 2

Theories of Everything- Life part 4- Astrobiology

Theories of Everything- Reality Part 4 - Beyond Reality

Theories of Everything- Reality part 3- Living in the Matrix

Theories of Everything- Reality Part 2- The Multiverse

Theories of Everything - Mind Part 2 - Memory

Theories of Everything - Mind Part 3- Consciousness

Theories of Everything - Life Part 3 - The Future of Life

Will life survive- for how long and in what form?
These questions are examined in Part 3 of this series

Theories of Everything - Life Part 2 - Fast Forward

Life's Evolutionary Journey

Theories of Everything- Life-Part 1 - Origins

How did life begin? A review of the most plausible theories.

Theories of Everything- Building a Time Machine

 Time series- Interview with Professor Paul Davies

Theories of Everything- Time Part 2- Time Travel

An Introduction to the Possibilities of Time Travel in our Universe

Theories of Everything- Retro-Causality

Back to the Future

The equations of physics are generally time-symmetric, with no difference in function between the future and past. For example the theory of electrodynamics is based on waves travelling backwards and forwards in time.

Several experiments have been devised to test the notion of reverse or retro-causality including a variation of the classical quantum mechanics wave/particle experiment; delaying measurement until after the photons had passed through the double slit. However this was not deemed to be sufficiently rigorous as a proof, as the path the photon took before the measurement could not be verified.

Physicist John Cramer proposed a more rigorous test using the ‘transactional interpretation’ of quantum mechanics, which proposes that particles interact by sending and receiving physical waves that travel backwards and forwards through time. He has devised an experiment based on the entanglement of photons and their properties such as momentum, which then share the same wave or particle behaviour. Pairs of photons from a laser beam are entangled before being sent along two different paths. One stream is delayed by several microseconds by sending it through a 10k optical fibre cable.  A moveable detector can then be used to sense a photon in two positions, as either a wave or particle.

Choosing to measure the delayed photons as waves or particles ensures the photons in the other beam are detected the same way, because they are entangled. This choice therefore influences the measurement of the entangled photon even though it is made earlier.

If retro-causality is proved, it could solve the major enigma of quantum entanglement and non-locality, also analysed within the D-Net model; but at the same time would require a complete reformulation of the laws of causality.

Measuring one entangled particle could send a wave backwards through time to the moment at which the pair was created without being limited by the speed of light. Retro-causality might also help explain why we live in a universe so finely tuned to the existence of life as Paul Davies has speculated. The universe may be able to retrofit its parameters using reverse causality to ensure the emergence of life as we know it.

John Wheeler and more recently Jean-Francois Roch also showed that a ‘post-selection’ effect does in fact exist by measuring a photon that initially passes through both slits unobserved in a classic ‘double slit’ experiment as a wave. However after the initial experimental event; if it is measured or observed, it changes into a particle state.

This relates to the ‘Omega’ effect, defined by Professor Frank Tipler, which postulates that at the end of time in a universe, an ultimate observer- the Omega Point; the coalescence of all previous information and knowledge is generated, retrospectively bringing the universe and all its previous states, including life, into existence.

The author's evolutionary D-Net- Decision Network Theory also provides a possible mechanism to achieve a reverse engineering process, by allowing the exact retracing of the pathways encoded as evolutionary histories. The parameters of the big bang could then be adjusted by a reverse evolutionary process to provide a way of accelerating the selection of a form of life capable of evolving into a more efficient information processor. The presence of intelligent observers later in history could therefore exert an influence on the big bang to reverse engineer the most appropriate conditions for the emergence of an optimally efficient form of life.

The D-Net model would allow this possibility because a causal network would allow both reverse and forward pathways to be established as the most efficient history, similar to the application of reverse computing logic, which provides the lowest energy  cost or most efficient way to process information.

Biologically it has already been shown that life can be functionally reverse-engineered; for example producing chickens with teeth and snakes with limbs, by reversing evolutionary pathways.

In addition the latest interpretation of the Anthropic Principle suggests a much broader range of physical settings governing the creation of a universe, which could lead to the evolution of life as we know it. For example an alternate pathway has recently been formulated allowing life to evolve without the existence of the weak force. It may be possible to define many other evolutionary pathways that could result in alternate intelligent life forms, capable of efficiently processing information within different environments.

A major paradox associated with time travel has been the impact on the future of a messenger, particle or person, sent back in time. David Deutsch solved the problem by allowing two paths or ‘worlds’ to be generated for such a scenario. One path allows the time reversal process and its causal impact to take place, changing all events in its newly created world future. The other prevents the impact from occurring and so life goes on as before, along the original event pathway.

Recently Seth Lloyd and Aephraim Steinberg have gone one step further, experimentally proving that a time machine could be designed using the phenomenon of quantum teleportation.  By linking the particle to be teleported to the origin of two previously entangled quantum particles, its state may be transferred to the other. The causality changing effect of teleportation however never occurs. It appears that the universe has therefore protected itself from arbitrary interventions in its evolutionary trajectory.