Tag Archives: Books

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.

Merchants of Doubt

I watched a documentary yesterday entitled Merchants of Doubt, which is based on a non-fictional book by Naomi Oreskes and Erik M. Conway. It centers around public relations (PR) specialists who play “experts” on TV, radio and other forms of media. These PR specialists are hired by corporations (e.g. ExxonMobil, Philip Morris, etc.) to undermine scientific consensus in the public domain in a field of study where they have no formal expertise.

For instance, Philip Morris would hire many of these specialists to appear on TV as “authorities” to convince the public that there was no scientific consensus regarding the health effects of tobacco. When pitted against actual scientific experts on TV, these “authorities” are often aggressive and argumentative, thereby seeming to subvert the scientist’s message in the eyes of the public.

One of the most startling revelations from this documentary (at least to me), was the role played by two prominent physicists, Fred Singer and Frederick Seitz. Both physicists have aided in legitimizing the claims against anthropogenic climate change. Strangely, both figures had also played a role “in helping the tobacco industry produce uncertainty concerning the health impacts of smoking”. According to Wikipedia, Singer has also publicly questioned “the link between UV-B and melanoma rates, and that between CFCs and stratospheric ozone loss”.

Clearly, for these two physicists, there is a political element to these decisions, which cannot be based on sound scientific reasoning. It is deeply disturbing for me to know that the building in which I have worked for the previous few years, the Frederick Seitz Materials Research Laboratory, while an historic research facility, is named after a man who has purposefully eroded the public’s trust in the scientific consensus on anthropogenic climate change (paywall).

The Idea Factory

I recently read John Gertner’s book The Idea Factory: Bell Labs and the Great Age of American Innovation. It had some great insights into the role that a stimulating environment can play in the creative process and how management can cultivate such an atmosphere. Some of the products invented at Bell (such as the transistor, laser, solar cell, etc.) were conceived of many years prior to their invention and introduction into the public sphere, emphasizing  Bell’s long-term oriented goals. The book also describes the management’s role in protecting Bell’s scientists from having to worry about funding constraints and government intrusions.

On a more sinister side, it also described the large concessions that AT&T (which owned Bell Labs) had to make to the US government to maintain its monopoly status. It is clear that there were massive efforts on AT&T’s part to ensure that it could stifle its competitors.

The book also goes on to discuss the model of modern-day businesses and how they are different from the Bell Labs model. Where Bell was a monolith, much of today’s Silicon Valley businesses ascribe to a “fail quickly and often” philosophy which is in stark contrast to the Bell method. This part of the book is particularly interesting as it discusses some similarities between Google, among other companies, and Bell Labs.

There is obviously no right answer here as to how things should be run, but the book does contain little gems of insight that are definitely worth storing in a mental vault. It is worth a read.