Penrose, The Road to Reality

[Alan Sondheim]

Illiterate notes on Roger Penrose, The Road to Reality, A Complete Guide to the 
Laws of the Universe -

I've been reading this book slowly - which it demands; it's 1100 pages roughly. 
At this point, I'm almost finished - I want to recommend the book absolutely to 
anyone interested in contemporary pictures of the world. I wrote a comment on a 
science blog to this effect -

"The Road to Reality fascinates me for a number of reasons. It doesn't hold 
back on the mathematics, and gives enough bibliographic materials (online and 
offline) for background information. It also has an odd development of opinion; 
string theory is presented, partly in relation to Penrose's critical technical 
analysis, but also in relation to its "hip" content, picked up by the media. 
This is where Penrose's discussion of fashion in physics is critical - a 
discussion that should be applied to any number of fields (philosophy or 
sociology for two examples - where are Sartre and Parsons now?). The reader 
observes the working physicist throughout these sections, ignoring the cant and 
carefully evaluating claims - not only of string theory, for example, but of 
dim > 4 theories in general. There's another important point, I think - too 
often "popular" accounts gloss over the mathematics. For me the result has 
always been distorted notions that all-too-quickly are related to Buddhism, 
holisms, etc. etc. Penrose gives the complexity, if not the details, of the 
mathematics at work. It's an extremely hard read, but I couldn't put the book 
down; for once I felt that I was actually learning something about the working 
of physics _qua_ physics... - "

===

I want to add that a number of the models presented may also be useful, even 
for a non-mathematician for example, in thinking through the analog/digital 
distinction - which I think is related to the U -> R collapse that forms the 
central portion of the book (i.e. the wave equation doewn to a specific 
eigenvalue vis-a-vis measure- ment). Since I'm not a physicist, I'm not sure 
how this applies specifically to the Aristotelian logic of everyday life (i.e. 
without employing a beam- splitter or other sub-atomic particle/photon 
apparatus), but I have some ideas.

In any case, the work is brilliant. Hint - don't skip the math even if it 
proves almost unreadable (sections were for me); just go back and reread, look 
up the concepts elsewhere. As I mention above, physics without math is _always_ 
distorted; equations, theories, etc. just don't translate that easily. What 
happens is that equations -> metaphor as an explanatory mode; then metaphor1 -> 
metaphor2, etc. - and the "sphere of as-if" expands - as if, in other words, 
physics or at least physical theory or at least theory were _being done._ The 
concepts become a kind of legitimation-apparatus (which is what Sokal was 
after, I think), increasingly removed from faulty translation inthe first 
place. Reading Penrose is sobering in this regard, but incredibly illuminating 
- and as I indicate above, the gift to the reader is not only the 
(mathematical) physics, but also the _workings_ of physics and physicists; for 
example, on p. 952, the value of something called the "Barbero-Immirzi 
parameter" is given - and a footnote tells us that the value was found 
incorrect as the book was going to press. Physics is often incredibly generous 
in this regard; Gerald Feinberg, one of the "inventors" of the tachyon concept, 
once told me he wouldn't be perturbed if tachyons were never found (they 
haven't been as yet). Popper's falsifi- cation comes to mind, and Penrose 
critiques his work as well (pp. 1020- 1024). Read on...


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