Sunday, April 19, 2015

The Universe and Time

Some more on the recent book, Roberto Mangabeira Unger (a philosopher) and Lee Smolin (a physicist), The Singular Universe and the Reality of Time: A Proposal In Natural Philosophy.

Here are some passages from Massimo Pigliucci’s review, mostly of Unger’s portion of the book. Smolin and Unger think of this project as natural philosophy. Pigliucci quotes them on this:
Today, natural philosophy has not disappeared completely. It lives under disguise. Scientists write popular books, for the general educated public, professing to make their ideas about the science that they practice accessible to non-scientists. They use these books to speculate about the larger meaning of their discoveries for our understanding of the universe and of our place within it. They also have another audience, however: their colleagues in science, addressed under the disguise of popularization. (The Singular Universe, p. 82)
I’m interested in the argument about time. Here’s a passage from Pigliucci:
Time is, if I understand U&S correctly, simply the succession of causal connections between events. This succession can locally take place at a different pace, but this does not invalidate the universally true fact that certain things (like, most obviously, the Big Bang) happened before (meaning that they were causally antecedent to) others.

There are two crucial consequences of this way of looking at things: to begin with, that the laws of nature themselves can change over “time.” Indeed, they already have. U&S think that the universe has gone through at the least two phases, and possibly many more before those. One phase was the Big Bang and what happened immediately before and after. During this sequence of causal events (i.e., “time”) things were happening that did not abide to anything like the predictable regularity we see operating today, because the causal processes themselves were changing. The second phase is the one of the cooled down universe, which has gone on for billions of years now, and which can (to a good approximation, as Cartwright would say) be described as law-abiding, because the nature of the causal interactions that characterize it is either not changing or not changing appreciably. But this state of affairs may not last forever, and the universe may go through yet another period of upheaval, and so on and so forth, indefinitely.
I can go along with this. Back in my pluralist explorations I argued that the universe has evolved in several Realms of Abundance. One could see the emergence of a new Realm as requiring new “laws of nature.” I imagined three such Realms so far: Matter, Life, and Culture. As I understand Pigliucci’s exposition of U&S, those three Realms belong to their second phase, but I note that they seem to allow for “possibly many more before those.” So perhaps they could be convinced to differentiate their second into my three. In any event, I’d be inclined to add their Big Bang-centric first phase as another Realm, giving me four so far: 1) Primordial (that is, Big Bang, etc.) , 2) Matter, 3) Life, and 4) Culture. I’ve conjectured that we’re entering a fifth, which I’ve not named.

Pigliucci continues:
The second crucial consequence is that physicists should take cosmology seriously as a fundamentally historical science, to be modeled after some of the “special” sciences like geology and biology, not in the increasingly singular way in which fundamental physics proceeds. Indeed, the idea that the very regularities governing the universe change with the causal conditions appears odd only in fundamental physics, because it has been so influenced by abstract (and necessarily time invariant!) mathematics.
That’s fine with me. Historicity is very important. That, in effect, is why I treat Life and Culture as Realms differentiated from Matter. They involve different orders of temporality, different kinds of causal processes.

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