Tag Archives: Books

On Scientific Inevitability

If one looks through the history of human evolution, it is surprising to see that humanity has on several independent occasions, in several different locations, figured how to produce food, make pottery, write, invent the wheel, domesticate animals, build complex political societies, etc. It is almost as if these discoveries and inventions were an inevitable part of the evolution of humans. More controversially, one may extend such arguments to include the development of science, mathematics, medicine and many other branches of knowledge (more on this point below).

The interesting part about these ancient inventions is that because they originated in different parts of the world, the specifics varied geographically. For instance, native South Americans domesticated llamas, while cultures in Southwest Asia (today’s Middle East) domesticated sheep, cows, and horses, while the Ancient Chinese were able to domesticate chickens among other animals. The reason that different cultures domesticated different animals was because these animals were by and large native to the regions where they were domesticated.

Now, there are also many instances in human history where inventions were not made independently, but diffused geographically. For instance, writing was developed independently in at least a couple locations (Mesoamerica and Southwest Asia), but likely diffused from Southwest Asia into Europe and other neighboring geographic locations. While the peoples in these other places would have likely discovered writing on their own in due time, the diffusion from Southwest Asia made this unnecessary. These points are well-made in the excellent book by Jared Diamond entitled Guns, Germs and Steel.

If you've ever been to the US post-office, you'll realize very quickly that it's not the product of intelligent design.

At this point, you are probably wondering what I am trying to get at here, and it is no more than the following musing. Consider the following thought experiment: if two different civilizations were geographically isolated without any contact for thousands of years, would they both have developed a similar form of scientific inquiry? Perhaps the questions asked and the answers obtained would have been slightly different, but my naive guess is that given enough time, both would have developed a process that we would recognize today as genuinely scientific. Obviously, this thought experiment is not possible, and this fact makes it difficult to answer to what extent the development of science was inevitable, but I would consider it plausible and likely.

Because what we would call “modern science” was devised after the invention of the printing press, the process of scientific inquiry likely “diffused” rather than being invented independently in many places. The printing press accelerated the pace of information transfer and did not allow geographically separated areas to “invent” science on their own.

Today, we can communicate globally almost instantly and information transfer across large geographic distances is easy. Scientific communication therefore works through a similar diffusive process, through the writing of papers in journals, where scientists from anywhere in the world can submit papers and access them online. Looking at science in this way, as an almost inevitable evolutionary process, downplays the role of individuals and suggests that despite the contribution of any individual scientist, humankind would have likely reached that destination ultimately anyhow. The timescale to reach a particular scientific conclusion may have been slightly different, but those conclusions would have been made nonetheless.

There are some scientists out there who have contributed massively to the advancement of science and their absence may have slowed progress, but it is hard to imagine that progress would have slowed very significantly. In today’s world, where the idea of individual genius is romanticized in the media and further so by prizes such as the Nobel, it is important to remember that no scientist is indispensable, no matter how great. There were often competing scientists simultaneously working on the biggest discoveries of the 20th century, such as the theories of general relativity, the structure of DNA, and others. It is likely that had Einstein or Watson, Crick and Franklin not solved those problems, others would have.

So while the work of this year’s scientific Nobel winners is without a doubt praise-worthy and the recipients deserving, it is interesting to think about such prizes in this slightly different and less romanticized light.

Book Review – The Gene

Following the March Meeting, I took a vacation for a couple weeks, returning home to Bangkok, Thailand. During my holiday, I was able to get a hold of and read Siddhartha Mukherjee’s new book entitled The Gene: An Intimate History.

I have to preface any commentary by saying that prior to reading the book, my knowledge of biology embarrassingly languished at the middle-school level. With that confession aside, The Gene was probably one of the best (and for me, most enlightening) popular science books I have ever read. This is definitely aided by Mukherjee’s fluid and beautiful writing style from which scientists in all fields can learn a few lessons about scientific communication. The Gene is also touched with a humanity that is not usually associated with the popular science genre, which is usually rather dry in recounting scientific and intellectual endeavors. This humanity is the book’s most powerful feature.

Since there are many glowing reviews of the book published elsewhere, I will just list here a few nuggets I took away from The Gene, which hopefully will serve to entice rather than spoil the book for you:

  • Mukherjee compares the gene to an atom or a bit, evolution’s “indivisible” particle. Obviously, the gene is physically divisible in the sense that it is made of atoms, but what he means here is that the lower levels can be abstracted away and the gene is the relevant level at which geneticists work.
    • It is worth thinking of what the parallel carriers of information are in condensed matter problems — my hunch is that most condensed matter physicists would contend that these are the quasiparticles in the relevant phase of matter.
  • Gregor Mendel, whose work nowadays is recognized as giving birth to the entire field of genetics, was not recognized for his work while he was alive. It took another 40-50 years for scientists to rediscover his experiments and to see that he had localized, in those pea plants, the indivisible gene. One gets the feeling that his work was not celebrated while he was alive because his work was far ahead of its time.
  • The history of genetics is harrowing and ugly. While the second World War was probably the pinnacle of obscene crimes committed in the name of genetics, humans seem unable to shake off ideas associated with eugenics even into the modern day.
  • Through a large part of its history, the field of genetics has had to deal with a range of ethical questions. There is no sign of this trend abating in light of the recent discovery of CRISPR/Cas-9 technology. If you’re interested in learning more about this, RadioLab has a pretty good podcast about it.
  • Schrodinger’s book What is Life? has inspired so much follow-up work that it is hard to overestimate the influence it has had on a generation of physicists that transitioned to studying biology in the middle of the twentieth century, including both Watson and Crick.

While I could go on and on with this list, I’ll stop ruining the book for you. I would just like to say that at the end of the book I got the feeling that humans are still just starting to scratch the surface of understanding what’s going on in a cell. There is much more to learn, and that’s an exciting feeling in any field of science.

Aside: In case you missed March Meeting, the APS has posted the lectures from the Kavli Symposium on YouTube, which includes lectures from Duncan Haldane and Michael Kosterlitz among others.

Flash Boys: A Few Lessons

In the past couple weeks, I was able to get my hands on and read (finally!) Flash Boys by Michael Lewis. It tells the story of a few honest guys that try to stir up the way business is done on Wall Street, with the main protagonist being Brad Katsuyama, a former employee at the Royal Bank of Canada. There are some startling revelations in this book, some of which are relevant to physicists that go onto work on Wall Street, and some that apply more generally.

During my time in graduate school, I saw a fair share of theoretically-trained physicists (that tended to be quite computationally proficient) go onto work at high-frequency trading (HFT) and investment banking firms. I don’t see this as necessarily a negative trend (especially for those that are working in investment banks rather than HFT firms), but this largely depends on the roles the physicists are hired to fill. In speaking to the physicists who have gone onto work on Wall Street, many of them have been attracted by the interesting puzzles/problems they are given to solve.

One of the main themes of the book is that the physicists, mathematicians and other STEM PhDs that work on Wall Street are often prevented from understanding their own roles within their companies. What I mean by this is that upper management in many Wall Street companies actively try to impede people with a more technical leaning from gaining a broad overview of the firm’s intentions and its role in the economy as a whole. The PhDs are hired to solve puzzles, not to understand the meaning of the puzzles they are solving. Indeed, many STEM PhDs are not even interested in knowing the consequences of the problems they are solving. This is just one of the parts of the book that I found to be particularly disturbing.

For those STEM PhDs that are thinking of going to work on Wall Street, Flash Boys is one of the most insightful and accessible reads one is likely to find. In stark contrast to the management at many of these firms, the book seeks to provide one with an overview of what has occurred on Wall Street since 2007. In it, Lewis describes the reasons behind the rise of dark pools and other public stock exchanges (i.e. the fragmentation of trading sites), why optical fibers that connect, e.g. Chicago exchanges to New York exchanges, are of immense value to HFT firms, how HFT firms essentially provide an unwanted tax to investors in the American stock market, and how investment banks’ (e.g. Goldman Sachs’) incentives don’t always align with those of their clients.

Since the writing of the book, things have started to change somewhat on Wall Street. Brad Katsuyama and his team have opened up the IEX (Investors Exchange), which seeks to prevent high-frequency traders from teasing out information about investment strategies employed by mutual funds, hedge funds, and individuals who invest from home. (This information can be used by HFT firms to front-run.) Even as things change, the book is without a doubt still very relevant today and is highly recommended, especially for those seeking a job on Wall Street.

On a more general level, one of the lessons I took from the book was about the need for introspection. It is sometimes necessary to ask oneself questions such as:

  1. What are the broader consequences of my work?
  2. What are the possible unintended consequences?
  3. What are the societal impacts?
  4. Are these consequences long or short term?

Even though we choose to pursue the seemingly singular goal of scientific knowledge and understanding, we do have a role to play in the broader society as well.

A Much Needed Textbook Overhaul

It is well-accepted in the community that the quality of introductory textbooks in condensed matter physics were decent but not great just up until a few years ago. At US universities, it is common to be exposed to condensed matter physics for the first time through either Kittel’s Intro to Solid State Physics or Ashcroft and Mermin’s Solid State Physics.

While both books have a number of redeeming qualities, they don’t possess the trifecta of (i) being modern, (ii) being easily accessible to a novice (aided by having a conversational tone), and (iii) targeting physical insight/perspective over an information glut. These books possess great problems and are an excellent reference to those who already are well-acquainted with solid state physics, however. I will mention that Ziman’s Theory of Solids, while infrequently used at US institutions, is a great little book — though again probably not appropriate for a complete novice. These books were all written by theorists.

In the past few years, however, there has been an excellent collection of books released under the Oxford Masters Series (OMS) umbrella. These books tend to be more pedagogical and conversational, shorter in length and necessarily more modern. They would be much more appropriately described as bedtime reading compared to the counterparts mentioned above. There are a few books from the OMS that I have read from cover to cover, and some where I have just read a few chapters. These include the following titles:

  1. Band Theory and Electronic Properties of Solids, J. Singleton
  2. Optical Properties of Solids, M. Fox
  3. Magnetism in Condensed Matter, S. Blundell
  4. Superfluids, Superconductors and Condensates, J. Annett
  5. Statistical Mechanics: Entropy, Order Parameters and Complexity, J. Sethna

There are two more great introductory-level books which, though not explicitly in the Oxford Masters Series collection, have been released through the Oxford University Press:

  1. The Oxford Solid State Basics, S. Simon
  2. Quantum Field Theory for the Gifted Amateur, T. Lancaster and S. Blundell

I have to say that I have been surprised with the consistent level of pedagogy that has been maintained over numerous authors in the series.

What these books are:

  1. Introductory level
  2. More data-driven (In particular, Fox’s, Singleton’s and Blundell’s books help one understand data from certain mainstream experimental techniques. This probably has to do with the fact that these authors are experimentalists.)
  3. Modern (e.g. there is a discussion of angle resolved photoemission spectroscopy and corresponding data in Singleton’s book)
  4. Focused

What these books are not:

  1. A complete and thorough treatment of the subjects (it could be argued that “less is more” in this case, however!)
  2. Mathematically involved
  3. Rigorous (sometimes almost appealing too much to intuition!)

Most of us learn in solitude with a good textbook/paper rather than in the classroom, and textbooks like these make it easier to get up to speed. I think that condensed matter physics will have a greater appeal at the undergraduate level in the US and other English-speaking countries due to the clarity of the OMS textbooks. The authors of these books have done a service to our sub-field and I much appreciate their effort. Lastly, the philosophical perspective of condensed matter physics has changed somewhat since the days of Kittel and Ashcroft and Mermin, and our textbooks needed to reflect this overhaul. They can now claim to do this.

Please feel free to comment on and recommend books, articles or papers that you found particularly useful. I am curious to know what else is out there, even if not originally an English-language text.

Just in case you thought otherwise: I was not paid by Oxford University Publishing to write this post.

Physics Over Formalism

Perhaps one could call it my “style” of doing physics, but I much prefer to understand phenomena in solids without the use of field theoretical techniques and formalism associated with those methods (i.e. Green functions, Imaginary time, Matsubara sums, Feynman diagrams, etc.). While many may consider it a necessity in the modern theoretical landscape, as an experimentalist I feel like I may be better off without the confusion that these methods elicit.

This attitude is undoubtedly in part due to the influence of A.J. Leggett, whose many lectures I have attended, and who presently eschews these methods dogmatically. In the previous years of my graduate studies, I spent innumerable hours trying to gain an understanding of the role that a Green function serves in solid state physics. I can discuss them fluently with theorists, but I never reached the level where the use of Green functions became second nature to me. I can say without reservation, though, that  I did not gain any significant insight from them that I did not already have from more basic methods.

After having made the conscious decision to leave these methods aside, I find myself liberated to some degree. I am able to concentrate on learning the basic physics that occurs in solids without the obfuscating (to me) formalism.

The strange thing I have noticed since “letting go” is that I have been able learn much more. This is so in two senses: (1) I have been able to gain a better understanding of phenomena that is commonly understood through the use of Green functions. The Random Phase Approximation (RPA) is a case in point. (2) Because I spend less time worrying about formalism, I have been able to cover more material.

There are a number of books that have advanced my understanding of solids that have not required the use of field theoretical methods:

  1. Quantum Liquids – Leggett
  2. The Theory of Quantum Liquids – Pines and Nozieres
  3. Electrodynamics of Solids – Dressel and Gruner
  4. Principles of the Theory of Solids – Ziman
  5. Superfluids, Superconductors and Condensates – Annett
  6. Topological Quantum Numbers in Non-Relativistic Physics – Thouless
  7. Introduction to Superconductivity – Tinkham
  8. Density Waves in Solids – Gruner

Comments are encouraged as I’m curious to know other peoples’ opinions on this matter.