Tuesday, November 18, 2008

Aether Makes a Comeback

The nineteenth century version of the ancient concept of the aether (or ether) was killed by the Michelson-Morley experiment and the success of Einstein’s theory of special relativity. Electro-magnetic radiation needed no substance to support wave propagation. Of course we did not revert to a view of space as an void sprinkled with a few solid objects. In modern particle theory, space-time is pictured as filled with matter fields. And in general relativity, space-time is revealed as a dynamic actor, not just a backdrop. Still, space-time remains distinct from matter/energy, and is geometric, rather than substantive. It thus retains a bit of the conceptual flavor of an empty container (a related discussion on the blog is here).

I was surprised to see the number of physics papers on arxiv which invoke the concept of aether (or ether) in the context of theoretical proposals to solving outstanding problems (e.g. dark energy). For me, aether was brought to mind by certain quantum gravity research programs.These propose that the space-time of general relativity is not fundamental: it emerges (along with the matter fields of the standard model) from something more basic – an underlying network of elementary quantum systems. This underlying network is not itself defined against a spatial backdrop and lacks the usual notions of distance or locality. Both space-time geometry and matter as we know them are constituted by the quantum systems: they arise from the aether.

For an example of this kind of work, here’s the second “quantum graphity” paper from Fotini Markopoulou and colleagues (the authors do not invoke the term aether, so don’t blame them!*). The introduction does a good job of discussing the stance they are taking toward the space-time of general relativity, and places this in the context of how other quantum gravity research programs approach the issue.

* Although they do link their work to the model described in this paper: “Quantum ether: photons and electrons from a rotor model” by Levin and Wen.

{UPDATED 19 November, 2008: Minor edits; 8 December 2008: Sean Carroll at Cosmic Variance just posted about his collaboration on aether field models.}

Friday, November 07, 2008

Ruminating on Theism and Personhood

As I’ve discussed in previous posts (see list below), one can try to put a theistic spin on my concept of the necessarily existing metaphysical “megaverse”: one can identify the megaverse with “God”. To be sure, it would be a non-traditional concept of God compared with that of our Western religious traditions – it would be a variety of panentheism (or perhaps panendeism). But perhaps this is simply stretching things too far, and using the label “God” is simply incongruous. Certainly there may be less room for confusion in communicating the ideas if one leaves “God” out of it (I think the historical reception given to Whitehead’s process metaphysics is a cautionary tale in this respect). While there are several considerations here, I think this decision of labeling should be driven in part by the question of personhood, which seems to be an important component of most conceptions of God.

I have a longstanding skepticism about the attribution of personhood to God -- if personhood means something similar to what it means in the human context. In the context of traditional religions, I always suspected anthropomorphism was at the root of this attribution. In outlining my version of the cosmological argument for a necessarily existing entity, I disliked even using the term “necessary being”, because it has the flavor of “human being”, and thus too readily invokes personhood.

Despite this skepticism, the panentheistic version of my view would say that human characteristics arise from the same raw materials which also constitute God, so there must be some essential affinity. Given my specific opinion that first-person experience is rooted in the most fundamental level of reality, I suspect that God might well be a subject of experience – a key aspect of human personhood.

On the other hand, when discussing Timothy O’Connor’s book (here and here), I disagreed with him on whether the necessary being (NB) needed to be considered an agent (and agency seems to be another key aspect of personhood). It seemed sufficient for the NB to be an impersonal font of creation without need of intentions, purposes, or discrete top-down decision-making. My thought here is that a human being moves within a sea of other beings or systems, and his/her agency arises in this context. The NB is the source and sum of all being, and does not operate in a larger context. This seems to me to be an important difference. To use an analogy: if a human being is an actor, then God is the theater, not another actor.

So, at this point I have a mixed verdict – our human essence is derived from the NB, but our status as a finite subset of the NB’s totality makes our nature very different. Whether the concept of personhood can be stretched to cover both situations is unclear, and I think the better option is to decline to consider the NB to be a person. And this may be a good reason to resist using the label God for what I have in mind.

Note: I’m even less well-read in relevant literature in this area than in other subjects I discuss: any reading suggestions in philosophy of religion are welcome.

Post Series (in chronological order): A Philosophical Path to Theism?

Modal Realism and the Cosmological Argument
Exploring the Borderlands
Whitehead's Philosophical Theism
Logos vs. Chaos, Part One
Logos vs. Chaos, Part Two
A Necessary Being or Just a Collection?
Why the Megaverse is a Unified Entity
Is the Megaverse a Subject of Experience?