This was a very interesting book. I have just a passing interest in the modern physics and its attempts to unify the forces and the particles. My last physics book was The Elegant Universe by Brian Greene, so I assumed that the String Theory (or various String Theories as it turns out) was it and it had been “proven” to be the only (?) viable theory in the contemporary physics scene.

Well, this book by Lee Smolin definitely put a huge doubt in that assumption. Although I don’t have the facility to independently verify all his claims, but he makes very convincing arguments against the String Theories as the unifying theory and its many unresolved issues (one of which is it has not been able to predict any new and unique experimental results). What came clear to me from Mr. Smolin (who was at one time a String Theory proponent) is that the String Theories have so many adjustable variables that they can be adjusted to fit any experimental results without uniquely predicting a new phenomenon (they haven’t been able to for the past 25 years or so).

The book is not only about the science. It is also about the sociological issues in the physics community. Mr. Smolin describes it as a society who is very susceptible to fashion, exclusive, hierarchical, and authoritative (mostly due to how the funding works). My first thought after reading his description was it really sounds like a religious organization. Mr. Smolin argues that the sociological atmosphere in the physics community (for the past 25 years or so) has made most of the brightest minds in physics to follow fads in the String Theories and has made exploration of other options very slow.

Anyway, I recommend this book to anyone who has interests in modern physics.

This is probably the first non-textbook physics book I’ve read since I read The Dancing Wu Li Masters : An Overview of the New Physics and The Tao of Physics in high school in the 80s. At the time, I was so much amazed and awed by quantum physics as illustrated by Gary Zukav and Fritjof Capra that I was pretty adamant about pursuing physics in college. (But then, I found computers! :p)

Anyway, the previous two books (published in mid- to late-70s) mostly dealt with quantum physics, briefly mentioning string theory. And from reading The Elegant Universe on the development history, I can see that the string theory had a long way to go at the time.

This was a fun read although a lot of the technical details toward the end were just over my head. Even without fully understanding the details, Greene‘s writing was very enjoyable and informative to me, although not quite inspiring as Capra or Zukav (or the Korean translators).

I was finally able to understand how the extra-dimensional spaces are “curled up” tightly according to the string theory, and what the implications and the challenges are for the modern theoretical physics.

I probably won’t get to apply or remember much from the book, but I was excited to follow the historical journey of probably the best candidate for the theory of everything.

Peter Lynds‘ paper “Time and Classical and Quantum Mechanics:
Indeterminacy vs. Discontinuity”, which is to be published in August in Foundations of Physics Letters, claims that there is no such thing as a static instant time and that the time can be only measured as an interval rising from the motions in space.

It seems there has been some “buzz” going on because it received such a spotlight in the mass media (or on the ‘Net). There have been many rebuttals pointing out some of the paper’s (potential?) fallacies. I am not much of a physics or a mathematics person, so it’s hard for me to determine by reading the paper, but I can, at least, tell that the paper isn’t much of a mathematical one, but more of a philosophical one.

Anyway, for me, some of the concepts described were interesting regardless of the paper’s validity. Especially, how we define “time”. Unlike other spatial dimensions, time seems to move only in one direction, varying only in relative rates of change. Maybe, time is not as independent as other dimensions and is only defined by changes in the spatial space. Or I am just speaking out of my a$$.

[Updated 2003-08-14] There is an interview with Mr. Lynds at Space.com.

As for the “(no) flow of time”… I don’t know why they say it’s hard to understand the Lynds’ ideas. Maybe it’s because I am not a physicist, but to me, it seems like how one defines motion and time, although I can’t say I have a total understanding.

The traditional approach is that we define motion with succession of singular time. On the other hand, the Lynds’ idea (it seems to me) is that the time is defined by motion.

A thought that just occurred. If we can take a snapshot of the world, which has a ball, at a singular moment, can we tell if the ball was moving or not? I don’t think we can. The motion cannot be defined with a “static instant time”. I think this is kind of a paradox similar to the Zeno’s since there is motion or no motion.

If one mentions momentum, electromagnetic properties, etc. to disagree, I’d say those are extra dimensional properties outside the space-time (i.e., those that can’t be described with the space-time coordinates). I am not sure even those can be measured when the time is “frozen” (i.e., those might also be defined by the time interval).

Anyway, I like the idea of defining time defined by the changes in other “physical” properties instead of infinite time slices. This is as unsatisfying as defining a plane with infinite slices of thickness-less lines. (Yes, and I am currently reading Flatland, too.)