Tallis: The Time of Our Lives

The Time of Our Lives


Raymond Tallis

But at the heart of the thermodynamic arrow and the notion that times can be defined by the comparative levels of disorder in the universe there is a deep confusion. We are still left with the fact that we have to determine, independently of any of their characteristics, which of two events, or even which of two states of the universe, is “earlier” and which “later.” The very idea that we progress from “less probable” (low entropy) states to “more probable” states seems to presuppose a temporal order, not to create it. Time, and the direction of time, is built into the very idea of change, of an entity moving from one (a prior) state to another (posterior) state, irrespective of what form the change takes. Without an independent sense of time order and the ordering of times, we could not have arrived at the Second Law.

It should by now be evident that the relationship earlier-to-later cannot be defined, even less created, post hoc by trends in the physical world, if only because those trends, being time trends, presuppose that “earlier” and “later” have already been established. Even so, philosophers and physicists have looked to even broader one-way or irreversible trends in the universe to account for the apparent unidirectionality of time, such as the cosmological arrow, to be found in the totality of the universe’s irreversible processes, or the arrow of radiation, which is illustrated by dropping a stone into a pool, resulting in concentric waves spreading across the surface of the water — clearly a process that could not go into reverse. But these arrows, too, fail to generate the requisite temporal asymmetry, the difference between the tip and the tail of the arrow, for the same reason as does the appeal to increasing entropy; namely, that we have already to identify that certain states are temporally prior to other states in order to register that there are trends which are irreversible.

This reminder of the contrast between the relatively information-poor future and the relatively information-rich past explains why it is insufficient to deliver time’s arrow. The arrow of information seems to merge two processes that should not be confused, never mind identified with one another; namely, states of the universe passing into knowledge (increasing information in the narrow sense, which is an epistemic difference) with passing into existence, from possibility to actuality (which is an ontological difference). The confusion is the result of the way that, in this context as in many others, the idea of “information” is widened to include the passage from indeterminacy to determinacy in the case of material events in the absence as well the presence of consciousness. Some explanation is needed.

The massive expansion of the catchment area of the word “information” is one of the most striking trends in recent philosophical and scientific discourse.