Books Unblogged: Spinoza Edition

Here are some books I enjoyed reading in recent months (which in a parallel blogging universe I discuss in greater detail.)

1. A Spinoza Reader (edited and translated by Edwin Curley).

I wanted to read Spinoza’s Ethics; this volume also contains some excerpts from other writings and correspondence. Among philosophers, Spinoza is comparatively easy to read. While his idea to write the Ethics in a Euclidean format was quixotic, it makes the discussion straightforward to follow and subsequently reference.

I like Spinoza’s metaphysics very much, so I’m inclined to say he was “way ahead of his time.” (Good SEP articles on Spinoza here and here). In any case, I think he’s right that the most viable view of God is as a maximal conception of Nature. We live in a finite locale within God’s infinite expanse. On the other hand, Spinoza failed to find an explanation for contingency and so endorsed necessitarianism (but see also here): ignorance is his explanation for our intuition of contingency (I’d like to travel in time and see what he would have made of quantum mechanics and the idea of objective indeterminism). I think his views about mind (thought and extension are two coequal aspects of the same reality) still make plenty of sense in today’s philosophical landscape. The latter parts of the Ethics get a little long-winded and pedantic, but include a variety of practical tidbits of wisdom about human psychology and how to live one’s life that will reward a re-reading.

It’s a wonderful world we live in where you can find multiple well-written popular books about Spinoza, too. I enjoyed

Quantum Interactions Create Space-time

The notion that spacetime is an emergent phenomenon is, by my reckoning, being proposed by an increasing number of thinkers. Physicists and philosophers working in quantum gravity and quantum foundations are turning to the idea that the spacetime of relativity is not fundamental, but rather something which arises from a more fundamental world of quantum mechanical systems and their interactions.

I just saw a reference to one such argument which was made a few years ago in an article by Avshalom C. Elitzur and Shahar Dolev called “Quantum Phenomena Within a New Theory of Time”. This was published in the 2005 collection Quo Vadis Quantum Mechanics?, Avshalom C. Elitzur, Shahar Dolev, Nancy Kolenda, Eds.

Elitzur and Dolev examine several puzzles over the nature of time in quantum mechanics and are led to the hypothesis that quantum interactions (measurements) themselves are responsible for the creation of spacetime.

A couple of quotes from section 17.10, titled “An Outline of the Spacetime Dynamics Theory”:

Neither Special nor Trivial

Note: this is a navel-gazing post with no external links.

I'm thinking again about my modal realism and the status of the actual vs. the rest of the possibilities.  I summarized in a prior post (Actual as Indexical, After All?) my conclusion that, while my metaphysical model is very different from that of David Lewis, his idea that what it is actual is just what is local to a point of view made sense.  This implies that our actual world is not the result of a special creative outcome, and that we should probably assume that all metaphysical possibilities are actualized "somewhere" in modal space.  I saw this as just an extension of the Copernican trend familiar from science:  our local situation is not special; it's just another local neighborhood in a huge expanse of reality.

But more recently I've been reconsidering this.

Dieks on RQM

This is a quick follow up on the prior post.  Van Fraassen was a pioneer in the 1970's of the modal interpretation of QM (which became over time a family of interpretations), and he’s now clearly an admirer of RQM.  I'm not a careful student of the modal interpretations (here's the SEP article by Michael Dickson and Dennis Dieks), but the starting point involved an attempt to do away with the measurement collapse postulate (which was why I originally had a hard time getting interested in the program).  The goal was instead was to append actual values to dynamically evolving states.  The SEP article details the various challenges and developments over the years;  what was new to me was the fact that a subset of the philosophers involved had proposed a perspectival or relational approach in an effort to solve some of the problems.  These efforts come close to the spirit of RQM despite the very different starting point.  This is discussed in a recent paper by Dieks called "Objectivity in Perspective: Relationalism in the Interpretation of Quantum Mechanics".

Below for bookkeeping are some past posts on interpreting QM.

Van Fraassen on "Rovelli's World"

I’ve long been interested in Carlo Rovelli’s Relational Quantum Mechanics (RQM), and had been aware that philosopher of science Bas C. van Fraassen had an unpublished paper discussing RQM.  Recently, I saw that a preprint draft of this paper, called “Rovelli’s World,” had appeared on his website.

In the opening paragraph, van Fraassen calls RQM an “inspiring” original vision, and says “its presentation involves taking sides on a fundamental divide within philosophy itself.”  Unfortunately, he doesn’t return explicitly to this last statement (and there is no conclusion section in the paper), but it is pretty clear that the key controversy of RQM revolves around the issue of realism.  RQM seeks a consistent and complete interpretation of a quantum mechanical world, but this comes at the expense of fully objective realism.  We give up the idea of absolute observer-independent quantum states, likewise observer-independent values of physical quantities; “the theory describes only the information systems have about each other.”

The main content of van Fraassen’s paper is a careful exercise in analyzing RQM to see what higher-order aspects of the world it describes are actually “absolute” (or objectively known) even as the states and measurement outcomes only exist relationally.  He wants to compare what Rovelli - qua the author of the paper on RQM - seems to know about the world, as opposed to what a particular system in the world (playfully denoted “ROV”) can know, assuming the theory is correct.  He looks at length at a specific example, where ROV is a third observer following on a “Wigner’s friend”-style example:  based on his analysis he concludes an additional postulate should be added to RQM to clarify the scheme.

Below the fold are my notes on the paper:  they are somewhat sketchy; please refer to the paper for the real deal.

Quantum Photosynthesis Update

There's an new paper in Nature (full text behind the paywall) which looks very interesting.  The authors found evidence that quantum coherent effects are utilized to drive more efficient photosynthesis in algae at room temperature.  This result, along with other research, suggests this is a ubiquitous aspect of photosynthesis in nature.  A SciAm article describing the research with quotes from team leader Greg Scholes is here.  Wired has an article here (hat tip: Cosmic Variance).  In other work on this topic, the research group behind the Engel, et.al. paper from 2007 (the subject of my post: "Quantum Biology Goes Mainstream") also has a new arxiv preprint with updated results.

I suspect that non-trivial quantum effects are widespread in biology, and I hope researchers continue to get the inspiration (and funding ) to continue these efforts.

Justifying Metaphysics to its Critics

There has been a (to me gratifying) rebirth of metaphysics in English-speaking philosophy over the last couple of decades. Now, just as in the past, there is a backlash coming from within the profession. One locus of the opposition comes from philosophers of science. Now one of the best contemporary philosophers of science, Craig Callender, has a draft paper (“Philosophy of Science and Metaphysics”) giving his own critical assessment of metaphysics, which he presents in a judicious and thoughtful manner. (For a recent bloggy example of the tension here, see the sometimes pointed debate down in the comments to this post at It’s Only A Theory.)

Callender believes metaphysics plays an important role in science itself as well as philosophy of science. But he thinks some metaphysics goes wrong by assuming too much autonomy from science: there is a “resurgent idea that metaphysicians have a wider domain of study than scientists.”  As a result:

Today metaphysics is again the target of deep suspicion. In fact, we are in the midst of a flare-up of historic proportions. Evidence of this comes from my bookshelf. Many recent books in philosophy of science possess entire chapters strongly condemning comtemportary analytic metaphysics.

Another Argument for Emergent Gravity

I have followed with interest a growing body of opinion among physicists that gravity (and space itself) is best thought of as an emergent phenomenon (most recently here).  Erik Verlinde has a paper, called On the Origin of Gravity and the Laws of Newton, which presents a heuristic case for gravity as emergent.

Unlike most of the other research papers I've blogged about, this is not a quantum gravity theory, but rather uses a number of concepts in mainstream physics (thermodynamics, the holographic principle) to derive emergent gravity.  He says that if one coarse grains a microscopic theory (whose precise dynamics need not be known), and applies the holographic principle to measure information on partition screens between particles, the information on the screens will give rise to an entropic force - this is gravity.

The paper has engendered discussion (I first saw it mentioned by Peter Woit here;  there is some appreciation here, and criticism here -- Verlinde responds here).  The main criticisms are that Verlinde's points are either not new, or that they embody circular reasoning (since concepts from Newtonian and post-Newtonian physics are used to derive Newtonian gravity).  Verlinde responds that he is bringing out a new insight which should help convince people that gravity is not a fundamental force, but is emergent.

I can't adjudicate the disagreements, but I think it's very suggestive that the argument for emergence continues to gain adherents.

I also think it is interesting to note that in Verlinde's model the microscopic theory, while not defined in any detail, must have a well-defined asymmeterical time dimension, as in the emergent quantum gravity theories I've reviewed.  "Time is fundamental, while space is not".

[UPDATE 22 Jan.2010:  A couple of more related links (HT).  A New Scientist article, and an illuminating preprint from Lee Smolin, who works through a Verlinde-type derivation in a different way, utilizing ideas from Loop Quantum Gravity research (altho note the specifics of LQG are actually not very important to the analysis).  He does a very good job placing the Verlinde work in context of other research and shows where it seems to add new value.]

Templeton Funds Initiative in Evolutionary Biology

[See also updates at the end of the post]

I just saw the news (here - I’m not sure if this was made public earlier) about the John Templeton Foundation's $10 million multi-part grant to fund “Foundational Questions in Evolutionary Biology” (FQEB), an initiative to be led by Harvard’s Martin Nowak.

Nowak has led what is called the Program for Evolutionary Dynamics at Harvard and has focused on the mathematical modeling side of evolutionary studies. The first announced effort is to offer fellowships to scholars pursuing envelope-pushing work on topics in evolution as well as the study of the origin of life.

I would like to learn more about this, but here are a few tidbits from the above links which are interesting. While the name evokes the earlier Templeton funding of the Foundational Questions Institute (FQXi), this program is more geographically centered (in Boston) and so, while not involving a new independent physical institute, it nonetheless is less “virtual” than FQXi. FQXi exists mainly to provide grants to scholars whose work in foundational physics might not otherwise garner funding from traditional sources. FQEB seem to be more people-driven (and Harvard/Boston oriented), and Nowak’s role seems crucial.

Importantly to me, however (as someone who watches Templeton -- see here and here -- and “roots” for them to apply their vast resources wisely), the initiative raises more potential controversy in terms of whether pure science will result from this effort versus a bias to search out and rationalize religion-friendly results. (This is not an issue with FQXi, which I think anyone who supports pure physics would be at least broadly pleased with):

• The stated goal includes a reference to "understandings of teleology and concepts of ultimate purpose".
• A Templeton officer says a “next phase of FQEB” will include “rigorous integrative work” with scholars in philosophy and theology. 
• The board includes a Divinity professor(!)
• Nowak, who has had affiliations with Templeton for some time, is himself is a committed Christian (was this a necessary if not sufficient fact in spurring this initiative?). A short essay where he expresses some of his views is here.

 The reason this is concerning, obviously, is that this country has faced an long and ongoing challenge to keep education in evolutionary biology free from interference from misguided religious folks.  The Templeton Foundation has disavowed any support for the most prominent recent political agitators in this area – the “Intelligent Design” movement -- and I think their efforts in supporting science/religion rapprochement have been harmless (if often wasteful, in my opinion). But why make a big effort in science funding in this crucial and sensitive area (which is a wonderful idea) and then contaminate it with any religiosity at all? That concerns me and I’m worried that it is a big mistake.

[UPDATE 8 Jan.2010: It seems the Templeton newsletter emailed to me on 6th January, which is my first link above, was the first public notice of this; the next blogosphere notice was today and comes from the "Intelligent Design" promoter, William Dembski, here. My brief opinion of ID is above and in an earlier blog post here.]

[UPDATE 20 Jan.2010: Templeton has announced funding priorities for the new year, and, of interest to this blog, they include Quantum Physics and the Nature of Reality and Foundational Questions in the Mathematical Sciences.]

[UPDATE 21 Jan. 2010: Also interesting to me is Templeton’s recruiting of journalist and blogger Rod Dreher to a post called a director of publications. His new blog is here (the first post is here). I assume it is no accident that he is a Christian conservative. There seems to be plenty of circumstantial evidence of an ongoing tension at JTF between the late founder’s clearly non-sectarian, progressive view of the religious impulse and the current Christian conservative leadership.]

A Crystallizing Universe

The use of a phase transition to describe reality pops up in this paper by George Ellis and Tony Rothman: “Time and Spacetime: The Crystallizing Block Universe.”

I had previously read Ellis’ contribution to the FQXi contest on time: “On the Flow of Time”. In that essay, Ellis criticized the notion of picturing the universe as an unchanging four-dimensional space-time block, and proposed a model of an “Evolving Block Universe”, which includes the indispensable notion of time flow. In this new paper, Ellis and Rothman fine-tune this idea.

They associate the flow of time with the transition from a quantum future to a classical past: this transition is marked by the time-irreversible process of quantum state-vector reduction (measurement). They note, however, that phenomena displayed in certain quantum set-ups (delayed choice and quantum eraser schemas) show that the transition process doesn’t take place uniformly. This non-uniform nature of the transition inspired the crystallization metaphor.

I like that Ellis takes quantum measurement seriously as a natural process (actualizing potentialities) and links this transition to the experienced flow of time.