Is Time Just A Trick Of The Mind? (read article)
Carlo Rovelli, one of the founder of Loop Quantum Gravity theory likes to think so. Furthermore wikipedia entry highlights:
This position has lead him to face the following problem: if time is not part of the fundamental theory of the world, then how does time emerge? In 1993, in collaboration with Alain Connes, Rovelli has proposed a solution to this problem called the thermal time hypothesis. According to this hypothesis, time emerges only in a thermodynamic or statistical context. If this is correct, the flow of time is an illusion, one deriving from the incompleteness of knowledge.
Background: Aristotle to Zeno
Aristotle, who pioneered many fields, writing treatises from Sleep to Dream Interpretation, Memory to Breath and of course from Soul to Time, defined Time as:
It is clear, then, that time is ‘number of movement in respect of the before and after’, and is continuous since it is an attribute of what is continuous.
Aristotle conceived time in relation to change or movement (BOOK IV, CH 12):
Not only do we measure the movement by the time, but also the time by the movement, because they define each other. The time marks the movement, since it is its number, and the movement the time.
After Zeno of Elea introduced his four paradoxes, Aristotle tried to dismiss the dichotomy in terms of potential and actual infinities. But to what extent? As Silagadze (2005) rightfully points out:
But all this mathematical developments, although very wonderful, do not answer the main question implicit in Aristotle’s rebuttal of Zeno: how the real motion actually takes place and whether its present day mathematical image still corresponds to reality at the most fundamental level.
Modern science tackles ancient problem
With advent of quantum mechanics, scientists are perhaps on a strong footing to answer the question. Rovelli, along with Connes, constructed a quantum mechanical system without time, perhaps for the first time, refuting Aristotle empirical notion that time and number must be interrelated concept. Formally TTH states:
The thermal time hypothesis. In nature, there is no preferred physical time variable t. There are no equilibrium states (rho sub zero) preferred a priori. Rather, all variables are equivalent; we can find the system in an arbitrary state (rho); if the system is in a state (rho), then a preferred variable is singled out by the state of the system. This variable is what we call time. (Rovelli 2008)
Time, according to Rovelli, is just an illusory concept. In conclusion he writes:
What we call the flow of “time” is the Tomita flow of the statistical state (rho) in which the world happens to be, when described in terms of the macroscopic parameters we have chosen.
Does Quantum Loop Gravity put a final nail to an age old paradox? If not, what are some major criticisms or flaws in Rovelli's theory?