The universe is made of matter and energy in a spacetime fabric. The matter can be converted into energy and vice versa, and the behavior of matter in this spacetime is governed by the laws of physics and the four fundamental forces; electromagnetic force, gravitational force, the weak and strong forces. The current understanding is that the classical physics (which includes relativistic physics) and the quantum physics respectively governs the behavior of the large (elements, molecules and the cosmic world) and the little (subatomic world). The space and time have received a great deal of attention in relativistic and quantum physics, and the basic questions pertain to whether spacetime is real or illusion. Author Lee Smolin suggests that time is real and space is illusion in his recent book (1).
The author describes his theory that time is not an illusion and describes his long held belief that the laws of physics evolved over billions of years (just like biological evolution which occurred over a much smaller time frame). He argues that this argument avoids the pitfalls of physics to explain universal physical constants and the use of anthropic principle. In the Newtonian paradigm, the law and the state/configuration exist in the universe, but unification of them requires a meta-configuration that has information about both. Here the reality is connected to the present moment. The choice of the initial configuration specifies initial law and the initial conditions, but the cosmological natural selection determines the law and the configuration, says physicist Lee Smolin. In the Newtonian physics; the time, the space, the laws and their solutions (possible histories of the system) are mathematical objects. But the mathematics does not correspond to actual processes but to records of them (once completed.) Hence they are timeless. The universe is evolving and expanding as a function of time but the Newtonian mechanics represents a small part of timeless universe.
The organization of matter from elements to molecules to stars and galaxies indicate that there is self-driven and self organization from myriads of subsystems and scales of ever increasing complexity. Stars act as the engines of this dynamics by the of fine tuning of universal constants, available fundamental particles & forces, the basic laws of physics and the anti-thermodynamic nature of gravity. The catch here is that these are only possible if the initial conditions during the birth of the universe are strongly time-asymmetric, i.e. time has to be real, says the author Smolin.
The future depends on whether we live in Leibnizian universe or the Boltzmannian universe. In the former the time is real in that no moment of time is like any other, but in the latter, there are moments in time that recur. In this dynamics, most moments are in equilibrium and they are roughly the same. In this universe if you wait long enough the universe will come as close as you like to repeating any configuration. If time is eternal, each moment repeats an infinite number of times. In Leibnizian universe, the opposite is true, no two moments are the same and this is possible if time real and the universe generate unique patterns and structures so that each moment is always different from others. Evolving complexity means that there never was a static complex system. It is dynamic and progressively becoming complex with time. This does not abrogate the second law of thermodynamics. The formation of complexity is compatible with an increase in entropy as long as the growing complexity is occurring in different places. The increasing organization on planet earth is driven by flow of energy from sun. Photosynthesis produces molecules with chemical bonds that represent orderliness and a decrease in entropy, but solar system is not an isolated system. The remaining energy not used in chemical processes is released into space as infrared photons that heats of a dust particle which will increase the entropy. If this increase is higher than the reduction of entropy in the biosphere, then the long term agreement with the second law is inevitable.
We can develop a good understanding that time and space are different. In fact in quantum physics, space emerges from a deeper order. From spacetime geometry emerging from a causal-dynamical triangulation model that show everything is potentially connected to everything else, then there must be a global time. The relativity of simultaneity of special relativity is a consequence of locality, and the distant events are not simultaneously connected because the speed of light imposes an upper limitation. In relativistic physics, we can determine two events are simultaneous when they occur at the same locality but in quantum physics a particle is potentially one step away from all other particles, everything is at the same locality. Then we can synchronize clock and have a universal time. When space emerges from such a model then so is the locality and constraints of special relativity. From this it appears that space may be an illusion and time may be real.
The principle of sufficient reason is essential because it sets a goal of discovering a rational reason for every choice the nature makes. The apparent free and uncaused behavior of quantum systems presents a strong challenge to this principle. There is a deterministic cosmological theory that gives rise to quantum physics whenever we isolate a subsystem and ignore the rest. It observes that quantum uncertainties originate because the quantum subsystem ignore the rest. These uncertainties are resolved by information about the universe which is hidden to the experimenter working on isolated quantum system. This hidden variable theory makes way for the application of quantum physics to the whole universe.
The idea of everything is local challenges the concepts of special relativity and hence special relativity is unified with quantum physics in quantum field theory. This is successful in predicting many experimental results but it is also hampered with infinite quantities that need to be normalized before any predictions are possible. The pundits of quantum physics argue that this is not about the physical world but about the information we have about it. It also denies an objective reality, therefore the hidden-variables theory was presented by Louis de Broglie according to which a real wave and a real particle exist for each particle such as electron. The theory states that wave influences where the particle goes but particle has no influence over the wave. This violates the principle of reciprocal action. Von Neumann suggested that hidden variables are impossible but David Bohm proved that it is possible and this theory is compatible with special relativity and also the quantum physics. In terms of statistical predications and also gave detailed picture of what goes inside individual experiment.
Physicist Lee Smolin proposes that the new cosmological theory should describe what we know about the universe, make testable predictions, explain why these laws, explain initial conditions, posit no symmetries or conservation laws. Nothing outside the universe should be required to explain anything inside the universe. It should satisfy the sufficient reason and reciprocal action and laws evolve with time with no fixed structures. Cosmological scenarios with evolving laws meets these conditions and it succeed in making predictions that does not rely on anthropic principles which states that the laws and the initial conditions are conducive for the life to be formed.
1. Time Reborn: From the Crisis in Physics to the Future of the Universe by Lee Smolin Houghton Mifflin Harcourt (April 23, 2013)
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