Wednesday, September 24, 2008

Paper on Entanglement in Biology

Through a search on arXiv I found a paper by Hans Briegel and Sandu Popescu called “Entanglement and intra-molecular cooling in biological systems? – A quantum thermodynamic perspective”. It made what struck me as a straightforward case for why non-trivial entanglement is plausible in a biological context, given that living things are open thermodynamical systems. The paper’s goals are modest: it does not present experimental results but just describes some toy models which motivate their argument. The authors believe research needs to be directed towards searching for signatures of entanglement in biological systems.

The authors do mention in passing that they think coherence on a very large scale, such as across the whole brain, is “virtually impossible”. If true, this implies that if brain processes exploit quantum effects, it is as a result of aggregation of such effects at the sub-cellular level.

As an aside, here’s the URL for the search I did on arxiv. This obviously only captures a small slice of what might be happening in this area, and specifically tilts toward the theoretical rather than experimental side of things. My unscientific impression is most of the papers here are being authored outside the United States. Hopefully a concrete result such as last year's detection of quantum effects in photosynthesis at Berkeley will accelerate research in this area everywhere.

Friday, September 19, 2008

2008-2009 GPPC Program

Here's a link to the Greater Philadelphia Philosophy Consortium's program for this year (the GPPC is a cooperative effort by 15 area universities to sponsor philosophy conferences and other programs). There is also a regional calendar which includes some other events taking place at member schools - the great majority are open to the public.

I'm looking forward in particular to the November 22 event at Swarthmore, "New Approaches to the Mind/Body Problem," which will feature talks from the phenomenological perpective on mind from Barnard College's Taylor Carman and Oregon's Mark Johnson.

Friday, September 12, 2008

Is the Megaverse a Subject of Experience?

My thanks to Justin, whose comment and question on the last post is prompting me to try to clarify some of my thinking.

Below I address his question of whether this “megaverse” I’ve discussed in the last couple of posts might be a cosmic-level subject of experience, given our shared endorsement of panexperientialism in the context of philosophy of mind. I tentatively think the answer is yes. Along the way I’ll try to better explain some of my reasoning and my use of terms.

The most common conception of the universe people have via science is that of a space-time container with matter/energy inside it. I’ve come to believe that this conception is wrong. I think it is likely that space-time itself is not a fundamental entity, but co-emerges with matter from a more fundamental level of quantum causal events. And the universe we see is only a slice of something larger (there are no boundaries – quantum gravity models imply that the big-bang was not a singularity, but arose from a pre-existing context).

So what we think of as the actual universe is an arbitrary slice of a larger reality, and it therefore doesn’t have a good claim to be a unified whole or a candidate for being a cosmic experiential subject.

What lies beyond our actual universe? Various motivations have led cosmologists as well as philosophers to propose the existence of many worlds or universes -- a multiverse. If these are completely separate worlds, then their existence would seem to have no impact on ours, but they might help explain the appearance of contingency and fine-tuning in ours. I’d note that the multiverse conception at first doesn’t seem to fit well with the idea of our universe as a cosmic subject – unless there is one such subject for every universe.

Again, though, what we call the actual world is not some space-time container with stuff inside, it is just the causally connected region or nexus we find ourselves in. So then it is wrong to think of the multiverse as a collection of distinct space-time containers. Even if we have not been in causal contact, these other parts of reality should not be thought of as completely separate realms. I’ve taken to calling this total reality the “megaverse” rather than the multiverse, given this way of thinking.

When thinking about the nature of this megaverse, I’ve connected it to my philosophical thinking on modal realism and causality. My modal realism leads me to identify the megaverse with the complete set of metaphysical possibilities (going beyond the multiverse motivations of physicists/cosmologists). My preferred model of causality leads me to see a close relationship between each actual event and the possible but not actual events which are also part of the megaverse. (Note also because “actual” just denotes “local” in this model -- actual is an indexical term -- what is an actual event vs. a possible event is not a fundamental distinction. All events are on an even footing.)

So, I’ve given the name megaverse to this largest conception of reality, and I see it as a holistic entity given the interdependence of its constituent-events. Let me come back, then, to the question of postulating a cosmic experiential subject: if all events have an experiential aspect, then it makes sense that the holistic network of all events is also the subject of (all) experiences. I’m not sure this makes the megaverse something which has consciousness or agency in a way analogous with the human variety. This is something to think further about.

Wednesday, September 10, 2008

Why the Megaverse is a Unified Entity

To continue the discussion from the last post, I sketch below some reasons why the metaphysical “megaverse” – the sum of all actual and possible events – should be considered a unified whole rather than a “mere” collection.

First, while I realize the field of mereology has been contentious for ages, I have always favored arguments that a whole is more than the sum of is parts (composition is not identity). I have several posts dealing with this in the context of trope theory: it appears that tropes cannot be bundled without an external unifier (I discussed Bill Vallicella’s arguments on this topic here and in the second half of this post). What could unify objects? The best answer IMO comes in terms of a theory which approaches composition via causation (see the paper discussed here for why this is a promising approach).

Moving specifically to my preferred event ontology, I think that participation in a larger causal pattern serves to unify constituent events into higher-level units (event complexes). Gregg Rosenberg’s theory on causation and natural individuals serves as an example of this approach (discussed here and here). To extrapolate, we can picture a hierarchy of causal patterns culminating in the largest one of all – the megaverse.

Further, because individual micro-level events in this model are actualizations drawn from a set of possible events, they simply cannot exist in isolation. The existence of an actual event presupposes a space of possibilities. I believe quantum physics provides a posteriori evidence for this feature of reality.

There are other possible arguments for the unity of the megaverse. For instance, the megaverse serves to ground necessary truths (such as those of arithmetic and basic logic). These truths extend throughout the megaverse, providing a unifying “shape” to events.

Also, the megaverse supports consciousness. In my preferred theory of mind, causation is inherently experiential, and the unification of constituent experiences is a defining characteristic of consciousness.

Much more can and should be said, but I think the case is good for considering the necessary existent to be a unified entity.

Wednesday, September 03, 2008

A Necessary Being or Just a Collection?

In Chapter 7 of his Metaphysics (paperback, second edition), Peter Van Inwagen discusses the cosmological argument for the existence of a necessary being. He critiques traditional formulations which invoke the Principle of Sufficient Reason (PSR), and then presents some versions which rely on premises weaker than the traditional PSR. He thinks some of these versions have more merit (but none support a truly compelling argument in his view).

Below I look at one of the versions he discusses, which I found interesting and helpful for the purpose of exploring an argument I’ve been favoring. A key premise in both arguments has to do with whether the sum of everything that exists is actually an entity or being in its own right.

The first premise of the argument from Van Inwagen’s book relies on the following principle: “Every being has this feature: the fact that it exists has an explanation” (p.125). If we accept this principle then, Van Inwagen argues, it is plausible to suppose that here are no beings which are both independent and contingent. To be independent means there can be no explanation in terms of other beings: therefore, given that we demand some explanation for existence, the only answer can be that the being’s non-existence must be impossible. Its existence is necessary rather than contingent. It follows that we can construct what might be called a Monist or Pantheist cosmological argument (my labels):

Monist or Pantheist Cosmological Argument (adapted from Van Inwagen, p.125):

1. There are no independent and contingent beings (premise)
2. There is a being which is the totality of all beings: the world (premise)
3. The world is an independent being (follows from 2)
4. The world is not a contingent being (from 1 and 3)
5. The world is a necessary being (follows from 4)

I think there are good reasons to accept premise 1, but I want to discuss here the fact that even if one accepts it, many would reject the second premise. As Van Inwagen explains, a naturalist typically has no problem seeing the contingent objects in the world as mutually dependent, without any need to postulate a world-being. Traditional theists also reject premise 2, since they see the necessary being as being distinct from its contingent creation. When it comes to our actual world, I also would reject premise 2: I don’t see a good reason to consider the totality of things an additional fundamental thing (I have a post related to this topic here).

The form of this argument, however, helped bring out an implied premise in my own modal realist version of the cosmological argument (first sketched here). This is the premise that the sum of all metaphysical possibilities is a kind of totality-entity in a way that the sum of all actual things is not.

Let me lay out the argument as follows (note that while I will use the term “beings” to be consistent with the discussion above, this would not normally be my choice):

Modal Realist (or Panentheistic) Cosmological Argument:

1. There are no independent and contingent beings (premise)
2. Modal Realism is correct: all possible as well as actual beings exist (premise)
3. There is a being which is the totality of all beings: let’s call this the “megaverse” (premise)
4. The megaverse is an independent being (follows from 3)
5. The megaverse is not a contingent being (from 1 and 4)
6. The megaverse is a necessary being (follows from 5)

So the question I want to ponder is this: is premise 3 here more defensible than the similar premise 2 in the earlier argument? I think so, but I haven’t argued directly for this before.

My preliminary thoughts go something like this.

Certainly, the megaverse is metaphysically exhaustive in a way that the actual world is not, and so has a better claim to independence and necessary existence. But could it just be a “mere” collection of possible and actual beings rather than a totality entity/being?

Recall that in David Lewis’ model of modal realism, the set of possible worlds is indeed a mere collection. For Lewis, each world is causally distinct (the actual world is simply the one we find ourselves in). In my preferred model, on the other hand, there is an intimate connection between the actual and the possible at the level of each individual event. Each causal event is an actualization of a possibility. So there is a continual closeness or adjacency therefore between what we see as actual and what is possible. The actual “world” is a causal network of events embedded in a larger framework of possible events (more related discussion here). So the “megaverse” is not a collection of distinct worlds, but is better seen as this transcendent framework which our ever-evolving actual “world” fits into.

Still, this doesn’t seem to rule out that at the level of events (rather than “worlds”); we could view the megaverse as a “mere” collection.

I’ve been scratching my head on this, and have some more thoughts, but I’ll save them for a follow-up post.