Jonathan Borwein and Keith Devlin are well-known mathematicians who have a strong appreciation of, and expertise in, experimental mathematics. In this book they provide us with a concise, inviting introduction to the field.

The first chapter tries to succinctly explain what experimental mathematics is and why it’s a fundamental tool for the modern mathematician. The following is their definition:

Experimental mathematics is the use of a computer to run computations—sometimes no more than trial-and-error tests—to look for patterns, to identify particular numbers and sequences, to gather evidence in support of specific mathematical assertions that may themselves arise by computational means, including search. Like contemporary chemists—and before them the alchemists of old—who mix various substances together in a crucible and heat them to a high temperature to see what happens, today’s experimental mathematician puts a hopefully potent mix of numbers, formulas, and algorithms into a computer in the hope that something of interest emerges.

They immediately address some of the possible objections and illustrate how an approach that doesn’t focus on formal proof, but rather on exploration and experimentation, ultimately leads to hypotheses which can then be, in many cases, proved analytically. The authors argue that in this sense, thanks to the aid of advanced computers, mathematics is becoming more and more similar to other natural sciences.

They also make a case for how great mathematicians like Euler, Gauss, and Reimann were doing experimental mathematics well before calculators where available. Their calculations on paper were far more limited than what computers afford us these days, yet they served them well when it came to sharpening and verifying their intuitions.

The rest of the book is a continuous series of examples that show the advantages of this approach in practice. The examples are highly interesting (some of them stunning) and tend to focus on calculus, analysis and analytical number theory.

Each chapter is accompanied by a section called “Explorations”. I found this section to be particularly valuable. Within it you’ll find exercises, and further examples and considerations. The answers/solutions to the actual problems are provided in the second to last chapter, just before the brief epilogue.

Chapter 2 discusses how to calculate an arbitrary digit for irrational numbers like , in certain bases. They illustrate how the so called BBP Formula (Bailey-Borwein-Plouffe formula, co-discovered by Jonathan Borwein’s brother) came to be.

The use of a program which implements the PSQL integer relation algorithm in high-precision, floating-point arithmetic was key to its discovery. The BBP Formula in turn allowed the calculation of the quadrillionth binary digit of back in 2000.

Chapter 3 focuses on identifying numbers, digits patterns, and sequences once you obtain a numeric result through your calculations and experimentation. They introduce the subject with relatively obvious values like the approximations of or , but the chapter quickly escalates to an example where a closed form for a seemingly random sequence needs to be found.

Chapter 4 analyzes the Reimann Zeta function from the eyes of an experimental mathematician, and shows us what kind of insight we can gain from this unique perspective.

In chapter 5 we learn how by numerically evaluating definite integrals, it is sometimes possible to identify the resulting value which will help us to analytically resolve those particular integrals. The examples presented in this chapter originate for the most part from physics and are very challenging if attempted without the aid of experimental methods. To better grasp the kind of integrals discussed in this chapter, here is an example:

The explorations section provides a few more interesting integrals, including some for which a closed form is not known. The authors even include an integral that intentionally stumps Mathematica 6 and Maple 11.

Chapter 6 is dedicated to serendipitous discoveries (“proof by serendipity”) with a few interesting examples of how “luck” met preparation, ultimately enriching the body of mathematical knowledge almost by chance.

In chapter 7 the authors go back to talk about , this time in base 10, to calculate its digits with efficient, fast converging formulas and methods. The chapter wraps up with a discussion about the normality of , which hasn’t been proved of course, but appears to be empirically supported by the statistical analysis of the first trillion digits. In the explorations section there is a nice discussion about the implementation of fast arithmetic through the Karatsuba multiplication, and the subject of Montecarlo simulations (a very inefficient method of calculating , but a great way to show the idea behind Montecarlo simulations).

Chapter 8 has a bold title, “The computer knows more math than you do”. This provocative title is quickly diminished to put it in context though. The authors start by approaching a tough problem posed by Donald Knuth (of TeX and The Art of Computer Programming fame) to the readers of the American Mathematical Monthly:

In an attempt to solve this the authors invite us to go on a journey involving the Lambert W function, the Pochhammer function, and Abel’s limit theorem. The rest of the chapter illustrates another difficult problem whose solution obtained through the aid of Maple has important implications not only for mathematics, but also for quantum field theory and statistical mechanics.

In chapter 9 a few infinite series are calculated in order to show how CAS systems and experimental methodology can still be useful when dealing with problems that involve infinite sequences, series, and products.

Chapter 10 is dedicated to the limits and the dangers of this approach. Several examples showcase how one can be misled into making assumptions, and how to avoid this from happening. The ad hoc example below is correct to over half a billion digits:

After having calculated a few hundred digits, it would be natural to assume that the series converges to a natural number, when in reality it’s an irrational and transcendental number.

In chapter 11, conscious of the selective focus on analysis and analytical number theory throughout the book, Borwein and Devlin introduce other examples such as a topology problem whose proof was reached thanks to a deeper insight gained through computer visualization of a surface, a knot theory problem, the Four Color Theorem, the Robbins Conjecture, the computation of , and so on.

In truth, I feel that such a thin book could have used more examples like the ones in chapter 11, in order to make a stronger case for the applicability of experimental mathematics to areas outside of analysis.

The book is well written and the tone is never heavy, despite the advanced mathematical examples within it. The authors include historical background and anecdotes which makes for a more interesting read and provides a human perspective behind the formulas presented. The (at times) funny illustrations and occasional jokes are definitely a pleasant addition.

This book is relatively tool agnostic; Maple and Mathematica are referenced throughout, and so are a few online tools to identify number sequences and known numeric values. Overall though, the emphasis in on the methodology rather than a particular CAS (Computer Algebra System) or programming language. In fact, with the exception of a snippet of Maple code in one of the explorations in the first chapter, the book describe the examples from a mathematical and algorithmic standpoint. You won’t find source code for the examples illustrated.

The ideal target audience for The Computer as Crucible is graduate students and researchers. A bright, motivated high-school student will get the gist of this book, but a more mature mathematical audience will actually be able to follow the steps within the examples and fully appreciate the insight on how an experimental approach can aid their research.

Despite the numerous examples employed to make their case, the authors start the book by explaining that it is not intended to be comprehensive. It’s meant to be thought provoking and to whet your appetite as to what is now possible in mathematical research thanks to computers.

As a computer programmer who’s passionate about mathematics, experimental mathematics fascinates me greatly. As such, I hope to work my way through the actual textbooks that are generally suggested as a follow up to this book. Namely, I’ve already started reading Mathematics by Experiment: Plausible Reasoning in the 21st Century (Second Edition), which is co-authored by Jonathan Borwein himself. Other textbooks referenced in this introduction are Experimental Mathematics in Action and Experimentation in Mathematics: Computational Paths to Discovery.

In conclusion, The Computer as Crucible is a lovely little book which builds a strong case for experimental mathematics. Any practicing mathematician or serious amateur should consider checking out this introduction to a topic that will no doubt transform mathematics.

Full disclosure: We received this book for free from the publisher, but we’re under no obligation to review or endorse it. We routinely receive a fair number of books from several publishers that never make the cut for an actual review. The links have our Amazon referral id which gives us a tiny percentage if you buy a book. In turn this helps support this site.

As noted in the last page of the pdf, I suggest calling the alternate constant 2 π=6.283… `1 turn’, so that 90 degrees is `a quarter turn’, just as we would say in natural language. The main point is that the historical choice of the value of π obscures the benefit of radian measure. It is easy to see that 1/4 turn is more natural than 90° , but π/2 seems almost as arbitrary. It is apparent that we can’t eliminate π but it is to be aware of its pitfalls, and introduce an alternative for those who might wish to use one.

— Bob Palais

Palais then goes on to define a “newpi” symbol through a TeX macro, which resembles the fusion of two π:

The aforementioned article has been in print since 2001, and very little has changed on this front since then. The ideas it put forth are an amusing opinion that many of us tend to agree with, but 2π has not been adopted by the mathematical community.

Today Michael Hartl announced “The Tau Manifesto” on what he calls Tau Day (6/28 for 6.28…). In this document, Hartl echoes the good points that Palais made and builds upon them to construct a strong case in favor of adopting a circle constant which is the ratio of a circle’s circumference to its radius, not its diameter. Inspired by Palais’ use of the word “turn”, he proposes calling this constant τ (tau).

As Hartl argues, this symbol already exists (unlike the odd symbol that Palais introduced), it’s still generally available in mathematics, and it resembles π.

This new constant would not only be an improvement from a pedagogical standpoint (as shown in the diagram above), but would also “improve” several formulas. For example, Euler’s identity:

Or:

Which would become neater as:

This makes sense intuitively (a rotation in the complex plane by one turn is 1).

(The Tau Manifesto addresses the issue of how this too can relate to the “five most important numbers in mathematics” with a slight rearrangement.)

What are your thoughts on this? As mathematics evolves, is it time to start using “Let τ = 2π” as a means of adopting a better circle constant?

1. I’m certain many of our readers would be interested in knowing how you got started. What led to your interest and love of the discipline?

Prof. du Sautoy: It was being exposed to real mathematics when I was at school. My teacher showed me some of the big stories of maths. We tend to focus too much on the vocabulary and grammar and forget to show kids the Shakespeare of maths. I was also lucky to attend the Royal Institution Christmas Lectures when they were first done on maths by Christopher Zeeman. I was very lucky to be given the chance to give the lectures myself in 2006 and this summer I am publishing a new book based on the lectures called The Num8er My5teries. The book is my manifesto for what we could be teaching kids.

2. Let’s talk about the perception of mathematics and science in today’s society. At a time where scientific awareness and reason are greatly needed to further progress the state of society and democracy, it appears to me that anti-intellectual, and in particular anti-scientific, stances are on the rise. It often seems that the majority of people believe they are not really expected to know much about mathematics and science, despite the far-reaching impact these disciplines have on our complex society and world.

Being “bad” at mathematics or failing to possess a fundamental grasp of other scientific areas is not only considered tolerable, but often flaunted without so much as a hint of shame. One would rightfully be considered ignorant for not knowing anything about Shakespeare, yet this is much less the case when dealing with the magnificent works of Euclid or Euler). At one extreme of the spectrum, there are also religious, political and economical pressures to invalidate evolution, global warming, and science as a whole. A recent reminder of the so-called war on science came through the high profile libel case against Dr. Singh. Thankfully that situation ended on a positive note when the judge concluded that, “Scientific controversies must be settled by the methods of science rather than by the methods of litigation […]”.

In your opinion, what is the best approach when it comes to fighting this trend and helping society to embrace reason and science? How do we increase trust in the scientific method and interest in the art of problem solving? How should we prepare the next generation to be more interested in mathematics and science?

Prof. du Sautoy: Increasingly our lives are being influenced by scientific developments which means that science impacts on everyone in society. By not engaging in the ideas of science you are effectively disenfranchising yourself from that debate. But it’s also the responsibility of scientists to be open to dialogue and share their science with society. That is why positions like the Simonyi chair for the public understanding of science are crucial in creating bridges.

I actually think there is an appetite for science among the public. TV, radio, newspapers and the bookshelves are full of interesting stories of science. I think we need to tap in more to the wonder and magic of science. Most scientists do science because they enjoy discovering how our universe works. I think most of us enjoy that feeling.

3. As a Simonyi Professor for the public understanding of science, you hold an important position that previously belonged to Richard Dawkins. As many know, his approach is very confrontational and direct. It places a great deal of emphasis on atheism and the damage that religion can – and often does – cause society. Despite being an atheist yourself (if we exclude your passion for Arsenal), it could be argued that you are a much less controversial figure and a diametrically opposite type of scientist. Could you describe how your strategy to promote the value of science and rational thought is different (from Dawkins) and how being a mathematician factors into this area for you?

Prof. du Sautoy: I think mathematics is a great choice for the chair. Mathematics is the language of science and bubbles underneath everything scientists do. It is probably at the other end of the scientific spectrum from evolutionary biology so it makes a good contrast. I see the role as an ambassadorial one, trying to create connections between society and the often foreign feeling land of science.

4. Your name is synonymous with the concept of symmetry. Can you briefly explain to our readers why symmetry is such an important topic?

Prof. du Sautoy: Symmetry is Nature’s language. Symmetry is present whenever there is structure or meaning. Our brains are evolutionarily programmed to be sensitive to symmetry. It is the key to our survival. It is also at the heart of many of the other sciences. Crystal structure and viruses depend on symmetry. Even the predictions we are making about what we might see in the LHC are thanks to a strange symmetrical object that exists in multidimensional space.

5. Can you tell our readers about your fund-raising project Symmetry4Charity, which helps provide kids from Guatemala with educational support? For those who haven’t read Finding Moonshine (published as Symmetry in the States), what led you to support a cause centered around Guatemala?

Prof. du Sautoy: I have two identical twin girls adopted from Guatemala (nothing to do with my obsession for symmetry). While living in Guatemala I encountered the charity Common Hope that gets kids in Guatemala off the streets and into education. Provided they stay in school their families receive health care and housing. It seemed a very empowering charity rather than one which made kids dependant. To help the charity I am naming new symmetrical objects that I have discovered in my research after people who donate to the charity. Just one more way that maths can help the world.

6. I personally find the idea of drawing out people’s philanthropic side by naming a symmetric group after them to be both fun and brilliant, so I donated to the initiative myself. Some may argue though that you are selling (albeit for a very worthwhile and noble cause) your discoveries. How would you respond to that sort of criticism?

Prof. du Sautoy: I think if I was personally making money out of the project there may be some justification to criticise the project. But I think it is a great way to engage people with cutting edge mathematics while at the same time helping one of the poorest countries in the world.

7. As not all of our readers are familiar with group theory, could you please describe, in layman’s terms, the process of finding new symmetric groups? Do you use any mathematical software in your workflow?

Prof. du Sautoy: My brain, a pencil and yellow legal notepads! That’s the best equipment for exploring the mathematical landscape. Because the symmetrical objects live in multidimensional space you can’t draw pictures or build them. Instead the language of group theory provides an algebraic way to show how the symmetries of this object interact with each other. These objects are very special because they are connected with another important subject in mathematics: elliptic curves.

8. What mathematical literature would you recommend to those members of the general public who are interested in exploring symmetry further? As well, what titles would you promote to the budding undergraduate student?

Prof. du Sautoy: My book Finding Moonshine tells the story of our journey to understand and classify what symmetries are out there. It is also a very personal book talking about my own work as a mathematician. I tried to give readers a back stage pass to the mathematician’s lab. For a deeper introduction I would recommend Conway et al’s The Symmetry of Things.

We wish to thank Professor du Sautoy for his time. We also highly encourage you to donate to his very worthwhile cause. Common Hope needs to raise £1000 from 50 unique donors by the end of April. Let’s make this happen. If they’re able to do so, they’ll receive a permanent listing on the UK Global Giving website that would allow UK donors to benefit from Gift Aid where tax is added to the donation. Common Hope is an educational charity supporting and empowering children and their families in Guatemala. Donate £10 or more and you’ll be entitled to request a symmetric group to be named after you (you can even name it after someone you care about, as a gift).

If you haven’t seen it yet, you can watch Professor du Sautoy’s TED speech below:

With Feedburner’s email service for example, I have no control over the emails that are sent out. With AWeber I’ll be able to create a newsletter service that not only sends out the posts I publish on this blog, but it will also allow me to send out custom written emails. I want to cultivate my newsletter and doing so starts with a service that allows me to do just that.

If you currently subscribe to my email newsletter via Feedburner you’re subscription will automatically be imported to AWeber and you will receive an email asking you to confirm the subscription. Unless you click on the activation link in that email, you will not be added to the new newsletter service. This is because the new newsletter has a double opt-in confirmation feature enabled. Starting tomorrow Feedburner’s email service will be disabled, as AWeber steps in to take over.

I invite you to join Math Blog’s newsletter by providing your first name and email address in the email sign-up on the homepage, or by clicking here.

Thank you to all those who sign up; I look forward to bringing my posts to your inbox via AWeber.

The list is not exhaustive by any stretch, capping at a total of 52 books so far, but it covers recommendations for 20ish different areas of mathematics. The focus is on outstanding introductory texts, with a few must-have math references thrown in here and there. We’ve briefly reviewed each of these math books in order to provide you with a general idea of its style and content.

Of course, not everyone will agree with the way we opted to divide the field of mathematics, nor will they necessarily agree with every selection we made. But it’s impossible to please everyone or be exhaustive in every way. We are confident that most readers will agree with us and recognize at least a few classic and well regarded books.

A lot of work went into the making of this page, as such we hope that it will serve you well, help you discover new and interesting titles, as well as act as a wish list of sorts.

Finally, this list of book reviews has been published with my name of it, but it was a collaborative effort. A special thanks goes to my friends Jonathan, Mary, Marco, Paolo, Alex and David for their research and review contributions.

May this list inspire and further guide you in the pursuit of mathematics.

I wrote about this event last year when a House Resolution was passed in favor of recognizing National Pi Day. The world is changing, and I feel that we’re slowly starting to see greater mainstream acceptance of how mathematics plays a vital role in some many of major fields.

Deep down, even students who claim to hate mathematics are aware of its importance and relevance in today’s world. With the attention recent Pi Days have generated, it’s clear that this “holiday” is becoming more and more mainstream, and not something that’s limited to a bunch of math geeks like us.

A quick look at Twitter, reveals that “Happy Pi Day” is a trendy topic, with literally thousands of tweets mentioning it. Even Google decided to honor this day by dedicating one of their logos to the occasion.

Year after year, awareness about this day continues to rise, which I feel is absolutely great for mathematics in general. But let’s transcend politics for a moment and enjoy our geeky day. Happy Pi Day to all of you! Tomorrow I’ll post about the new page I’ve been preparing for a while. It took scores of research, brainstorming and writing, but it’s almost ready. See you soon.

Pi paraphernalia
Pi movie | Pi biography | Pi T-shirt | Spiral Pi T-shirt | PI To The 50th Decimal Tie

With endorsements from star programmers and its unique user interface (UI), this site is very community oriented and aimed at highlighting the best answers and questions through a voting system. As such it has quickly become the number one programming forum, overshadowing the dreaded – and much shadier – Experts-Exchange.

However, what not everyone may know is that Joel and Jeff have made the platform available to others for a non-negligible monthly fee, at StackExchange. Over the course of the last few months several communities have grown out of this service, some more successfully than others.

The most successful of these sites is called MathOverflow. It currently has the largest number of active participants and voters on its posts. The site offers the same UI as StackOverflow, but adds in support for LaTeX formulas. Here at Math-Blog.com we feel it’s important to promote such nice initiatives.

From the look of things (such as the existing questions and answers), it’s clear that there is some serious mathematics going on at the site. If you’re looking for interesting discussions on topics at a graduate/research level, head over to MathOverflow – you won’t be disappointed. However, please keep in mind that the aim of the site is to target those with an interest in advanced math. If you’re seeking a more basic (read undergraduate) level of math assistance, you should probably look elsewhere.

That said, what are some the other graduate level forums and mailing lists that you find useful when it comes to your mathematical research? One of my favorites is the Number Theory List.

PS: I hope you like our new look. Be sure to drop by Math Blog this coming Monday, as we’ll be publishing a really interesting post that I’m sure you’ll love. In order not to miss it, you can also grab our feed.

The reasonable man adapts himself to the world; the unreasonable one persists in trying to adapt the world to himself. Therefore all progress depends on the unreasonable man. — George Bernard Shaw (attributed)

On November 11, 2002, Grigory Perelman, a Russian mathematician known to his friends as “Grisha”, posted a research paper to the www.arXiv.org preprint server containing, amongst other things, the outline of a proof of the Poincaré Conjecture, a famous conjecture in topology first articulated in 1904 by the great mathematician Henri Poincaré. Dr. Perelman also e-mailed a few selected mathematicians directly, drawing attention to his somewhat curious paper. This rapidly created a stir as the mathematicians realized that he might well have proven the Poincaré Conjecture, an extremely difficult problem that had eluded the talents of many top mathematicians including Poincaré. Perelman went on to post two more papers to arXiv.org elaborating his proof. The Clay Institute, which had offered a prize of $1 million for the proof (or disproof) of the Poincaré Conjecture, funded two teams of mathematicians to verify Perelman’s proof. The National Science Foundation also funded efforts to verify and expand upon the proof. By 2006, the “consensus” in the mathematical community was that Dr. Perelman had proved the Poincaré Conjecture. Dr. Perelman was offered the prestigious Fields Medal, close to the Nobel Prize of mathematics. He became the first mathematician to decline the Fields for reasons that remain somewhat unclear.

Two recent books attempt to tell the story of Grigory Perelman and the Poincaré Conjecture. Masha Gessen’s Perfect Rigor is the first biography of the elusive and enigmatic Perelman. It gives a great deal of information about the world of Soviet mathematics in which Perelman grew up and Perelman’s life to date. The author was unable to interview Perelman who has declined nearly all interviews; he has given an interview to Sylvia Nasar and David Gruber for their New Yorker article “Manifold Destiny“, about which more later. The book suffers from an unremittingly hostile, perhaps jealous, view of the unusual Dr. Perelman, who is variously portrayed as extremely naive, weird, and possibly mentally ill.

Dr. Perelman’s father was an electrical engineer and his mother a mathematics teacher at a Soviet trade school. His mother apparently had a strong interest in mathematics and almost pursued a doctorate before marrying his father. Perelman appears to have been involved in mathematics at an early age and joined a competitive math club. He competed and won a gold medal at the International Math Olympiad in Budapest, Hungary in 1982 at the age of 16. He attended a special math and physics school, Leningrad Secondary School #239, usually identified as “School 239″ in Perfect Rigor. He then became a student at Leningrad State University. In 1987, he became a graduate student at the Leningrad (subsequently the St. Petersburg) branch of the Steklov Mathematical Institute, the mathematics division of the Soviet (now Russian) Academy of Sciences. The mathematician Yuri Burago was his adviser. Perelman defended his dissertation in 1990. He continued to work at the Steklov Institute until 1992, publishing a number of papers in Russian and American mathematical journals.

In the fall of 1992, Perelman came to the United States for a semester at the Courant Institute at New York University and then another semester at the State University of New York Stony Brook in early 1993. At New York University, he met and may have become friends with the mathematician Gang Tian. Perelman and Gang Tian traveled together from NYU to the Institute for Advanced Study at Princeton to listen to mathematics lectures. Then, Perelman became a prestigious Miller Fellow at Berkeley. During this time he proved the Soul Conjecture, a difficult problem in topology. His Miller Fellowship ended in 1995. He received several job offers from a number of top universities. However, he wanted a tenured position. His job offers appear to have been untenured, tenure-track positions. He returned to Russia and the Steklov Institute in 1995 where he was part of the Mathematical Physics group, dropping almost entirely out of sight, publishing nothing. He appears to have spent the next seven years working on the Poincaré conjecture. In 2002, he stunned the mathematical world by posting his proof to the Internet, flouting tradition by declining to submit the proof to a peer reviewed mathematics journal. The Clay Institute would fund mathematicians John Morgan and Gang Tian (Perelman’s friend or acquaintance at NYU) as well as a separate team at the University of Michigan to verify Perelman’s work in the form of a peer reviewed academic book.

In 2006, the prominent mathematician Shing-Tung Yau and two of his former students argued that Perelman had published an incomplete proof which they “fixed” in a lengthy paper published in the Asian Journal of Mathematics. At this point the elusive Dr. Perelman appears to have struck back with a vengeance, possibly exhibiting something other than the naivete imputed in Pefect Rigor. Perelman granted a rare interview to Sylvia Nasar, best known as author of A Beautiful Mind about the mathematician John Forbes Nash, and David Gruber for an article in the New Yorker magazine, “Manifold Destiny,” which all but openly accused Yau and his former students of blatant plagiarism.

The article quotes Perelman attributing his decision to decline the Fields medal and withdraw from the mathematics profession to the low ethical standards of the profession (in his opinion). The article also discusses the alleged rivalry between Yau and his former student Gang Tian, Perelman’s acquaintance from NYU and co-author with John Morgan of the book on Perelman’s proof. Yau threatened legal action against the New Yorker which stood by its story. Yau soon appears to have retreated under a storm of negative publicity and criticism within the mathematics “community”.

By most accounts, Perelman is an unusual person. He left his job at the Steklov Institute and apparently resides with his aging mother in her apartment in St. Petersburg. He has reportedly indicated that he is no longer interested in mathematics and generally refuses interviews, prizes, and so forth. It is not unlikely that many prominent research universities and institutions would fall over themselves to offer him a tenured professorship or something similar if he expressed any interest. It remains to be seen whether he will decline the Clay Institute’s $1 million prize if offered. Without knowing more about Perelman and his adventures in mathematics than can be found in Perfect Rigor or other accounts to date, it is difficult to draw firm conclusions about the man or even his discovery.

Notwithstanding, a few thoughts come to mind. Perfect Rigor and some other accounts implicitly criticize Perelman for his decision to turn down the job offers in 1995 and return to the Steklov Institute, imputing arrogance or just plain nuttiness. Some mathematicians and scientists would kill for some of the offers that Perelman turned down. Most major breakthroughs take a long time, usually five years or more. Perelman spent at least seven years on the Poincaré conjecture and he probably was working on it while in the United States. Most tenure track positions involve a seven year period. The assistant professor is up for review typically in six years; he or she usually must produce allegedly ground breaking work within six years. If he or she is denied tenure, he or she has one year, the seventh year, to find another job. Most assistant professors have acquired a spouse and small children by this time. There is considerable pressure to produce research papers, write grant proposals and raise money. Perelman apparently published nothing from 1995 until 2002. He most likely would not have gotten tenure had he tried to do this at any of the jobs that he turned down in 1995.

There appears to be a long history of mathematicians developing serious psychological problems. The aforementioned John Forbes Nash succumbed to mental illness, diagnosed as paranoid schizophrenia, and was well known to Princeton students for wandering around campus scribbling incomprehensible formulas on blackboards. Kurt Gödel developed psychological problems and allegedly starved himself to death. Georg Cantor became increasingly erratic as he got older. There are many anecdotal accounts of high levels of concentration and mental efforts sustained over months or years resulting in a kind of mental exhaustion and other problems. Both the western and eastern literature of meditation, which often involves prolonged concentration, contain warnings about various adverse psychological effects including anxiety attacks and hallucinations. Disillusioned former adherents of various meditation movements or “cults” have alleged serious adverse effects of heavy meditation, meaning many hours per day every day, similar to those recounted in ancient traditional sources on meditation. Although computer programming can be exhilarating, many programmers appear to experience mental exhaustion and “burnout” after lengthy programming projects involving high levels of sustained concentration.

In engineering there is an adage: “if you are one step ahead, you are a genius; if you are two steps ahead, you are an idiot!” Perfect Rigor portrays Perelman as astonishingly naive, protected from the “real world” by the bizarre Soviet mathematical system. While this may have some truth, a number of Perelman’s actions may exhibit much foresight, like a champion chess player sacrificing a piece for subsequent gain. Is pretending not to notice the alleged anti-Semitism (Perelman is a Russian Jew) in the Soviet mathematical system naive or politically astute? Declining the Fields medal, as some have noted, attracted enormous attention to Perelman. He is now one of the best known recipients (or non-recipients in this case) of the Fields Medal. It also gave him a great deal of moral authority which he seems to have used effectively to fend off Shing-Tung Yau’s alleged attempt to steal credit for proving the Poincaré Conjecture. Refusing to grant interviews also means that Perelman probably has a great deal of leverage with journalists in the rare cases when he grants an interview, as he did with such great effect in The New Yorker in 2006.

Perelman was a math prodigy, returning home with a gold medal and a perfect score from the 1982 International Math Olympiad. Prodigies are often not as successful as one might expect. Math and physics prodigies often flame out, sometimes catastrophically. While prodigies are more common among people who make major inventions and scientific discoveries than in the general population, they are not nearly as common as most people probably think. Perfect Rigor portrays Perelman’s success in proving the Poincaré Conjecture as a logical consequence of his youthful training and competition in the sometimes bizarre Soviet mathematical system. Since Perelman has revealed little about the process of his discovery, this is difficult to evaluate.

Prodigies often run into problems and don’t realize their seeming potential later in life. This has been observed in math, physics, and other fields for many generations. There are probably several causes. Some prodigies are probably frauds, manufactured by ambitious parents; that such people fail to make major breakthroughs is not surprising. Some prodigies are probably the product of a hothouse environment, driven or manipulated by parents or others to practice heavily and perform at an unusually high level that is difficult to sustain. As they get older and establish their own lives, other interests or needs intervene. Some prodigies undoubtedly fall afoul of politics that they are ill-prepared to deal with.

Academic homework, exams, competitions like the International Math Olympiad, admissions exams such as the SAT or GRE exams in the United States, specialized exams and competitions such as the famous Putnam math examinations, and so forth do not necessarily either teach or measure some of the skills required in actual invention or discovery. Exams and homework in math and physics tend to test the ability to accurately and quickly perform certain calculations or apply certain known mathematical methods to a problem. Some people either through heavy practice or rare natural ability can learn to perform these calculations rapidly with negligible error. This does not translate directly into the ability to handle unsolved research problems which often seem to require large amounts of frustrating trial and error and often deeper understanding of concepts, mental visualization, and so forth.

Many topics taught at a high school, college, and even beginning graduate school level are quite mature. Logical and technical flaws that abound in original research papers have been cleaned up and eliminated. Teachers and textbook writers have learned how to present the material clearly so that a bright or highly motivated student may be able to easily master the material quickly. Prodigies can sometimes read a textbook and immediately start performing the methods described in the textbook very accurately. This becomes more difficult as one reaches the “bleeding edge” where the available learning materials are original research papers or badly written textbooks that may contain errors, impenetrable jargon, opaque language, and even deliberate obfuscation of logical or technical flaws. Prodigies may encounter a sudden drop off of their remarkable abilities which they may inaccurately attribute to a lack of the magic “ability” required for the field rather than the immature state of the bleeding edge knowledge. Perelman presumably navigated these difficulties as he progressed in mathematical research.

One is reminded of the old sayings “actions speak louder than words” and “talk is cheap”. If Perelman’s proof stands the test of time, he has done much. If he is sincere in declining prizes, honors, and adulation, he sets an example by his actions. In reading Perelman’s story, one also cannot shake the impression that he may have had some unhappy experiences during his stay in the United States and went home silently vowing “I’ll show them,” which he apparently has.

The Poincare Conjecture

Donal O’Shea’s The Poincare Conjecture is a more pleasant book to read than Perfect Rigor, lacking the hostile tone of Perfect Rigor and sugar coating a number of topics. Perelman is “eccentric”. Little is said about “Manifold Destiny” or the ugly priority dispute. O’Shea focuses on the history of geometry, the Poincaré Conjecture, mostly inspiring stories about great mathematicians, and tries to explain the mathematics of the Poincaré Conjecture to a general audience.

On the whole, The Poincare Conjecture is an enjoyable and informative book to read. O’Shea carefully debunks the myth that scholars in the Middle Ages and the ancient world believed the Earth was flat. He gives an interesting account of Columbus, the slow discovery of the exact shape and geography of the Earth, confirming the ancient theory of the spherical Earth. He slowly and deftly leads the reader through the history of mathematics and geometry to the Poincaré Conjecture, the many failed attempts to prove it, and the seeming final solution by Perelman.

Some of the illustrations leave a bit to be desired. In discussing mathematics in the ancient world, O’Shea uses modern CIA maps of the modern world to show the ancient Greek kingdom of Ionia where Pythagoras was born and to show the Middle East. One map, for example, shows modern Bulgaria which did not exist in the time of Pythagoras. Similarly, O’Shea is discussing ancient Babylonia and Persia but the associated map shows modern Iraq and Iran. Hopefully, this will be fixed in a future edition.

Some of the discussion of hyperbolic geometry and most of the chapter on Poincaré’s topology papers, which presents the actual Poincaré conjecture, could be improved. The diagrams and explanation on page 27 in the chapter “Possible Worlds” showing how the surface of a two-holed torus can be mapped to an octagon is hard to follow. O’Shea returns to the two-holed torus and the octagon in Chapter 10, “Poincaré’s Topological Papers”. Probably many readers will have forgotten the discussion on page 27 by then. The term “natural geometry” is used in this chapter but not defined clearly. A number of diagrams in this chapter are small and difficult to follow. Interested readers can find a better explanation of some of the relevant aspects of hyperbolic geometry in the second chapter of Roger Penrose’sThe Road to Reality which features some entertaining Escher prints showing the so-called “Poincaré disc model” of hyperbolic geometry (first discovered not by Poincaré, but by Eugenio Beltrami, Penrose carefully points out).

One can only go so far with analogies to rubber sheets or cloth fabric in describing topology and especially differential geometry. This is a problem many popular mathematics and science books encounter. If we had a better way of explaining and introducing differential calculus to a general audience, this would improve the general public’s ability to follow issues in mathematics and science and also improve our educational system.

Pure mathematics today suffers from a particularly opaque and confusing language. It now typically takes several months for a skilled person to master the arcane language of modern pure mathematics. Abstraction has been taken to an extreme. Words and phrases such as “algebra”, “ring”, “module”, “field”, and so forth have meanings in pure mathematics that differ both from common usage and the language of applied mathematics used in most engineering and also much physics. The Poincare Conjecture suffers in places from terms like “natural geometry” that have a special meaning in pure mathematics.

Conclusion

Both books focus on the genius of Perelman and famous mathematicians such as Gauss, Riemann, Poincaré, and others. Indeed, the subtitle of Perfect Rigor is “A Genius and the Mathematical Breakthrough of the Century”. This superman theory of scientific progress and a strong focus on extreme intelligence is common in popular science and math books and articles.

The story of the Poincaré Conjecture, at least until Perelman, is a story of large amounts of trial and error (lots of error) as both books allude to. Henri Poincaré formulated the conjecture in 1904 and published an incorrect proof. Almost every year has seen publication or presentation of attempts to prove the Poincaré Conjecture. Numerous mathematicians, including very top mathematicians, have published incorrect proofs. Many different approaches to the problem have been developed. Most failed. Richard Hamilton developed the basic approach that Perelman built upon but apparently stopped making progress in the 1980′s or early 1990′s. It is common to find large amounts of trial and error in the detailed history of inventions and discoveries, including discoveries in pure and applied mathematics.

It is clear that Perelman spent at least seven years on the Poincaré conjecture. We have no idea how much trial and error and how much failure took place during those seven years. Perelman reportedly fixed two minor errors in his first paper in the subsequent two papers posted to www.arXiv.org in 2002 and 2003. Other inventors and discovers have frequently gone through long periods of trial and error and repeated failure before their “breakthrough”. While respecting Perelman’s accomplishments, we should also be interested in the precise process used to reach the answer and avoid attributing it to magical genius alone.

Both Perfect Rigor and The Poincare Conjecture are interesting and informative books for general audiences. Even practicing mathematicians may gain some insights and new information from Perfect Rigor. Yet, Grigory Perelman remains an enigma. A definitive biography remains to be written. The world might learn a lot from more details on how he discovered his proof of the Poincaré Conjecture.

(C) Copyright 2010, John F. McGowan, Ph.D.

About the Author

John F. McGowan, Ph.D. is a software developer, research scientist, and consultant. He works primarily in the area of complex algorithms that embody advanced mathematical and logical concepts, including speech recognition and video compression technologies. He has extensive experience developing software in C, C++, Visual Basic, Mathematica, and many other programming languages. He is probably best known for his AVI Overview, an Internet FAQ (Frequently Asked Questions) on the Microsoft AVI (Audio Video Interleave) file format. He has worked as a contractor at NASA Ames Research Center involved in the research and development of image and video processing algorithms and technology. He has published articles on the origin and evolution of life, the exploration of Mars (anticipating the discovery of methane on Mars), and cheap access to space. He has a Ph.D. in physics from the University of Illinois at Urbana-Champaign and a B.S. in physics from the California Institute of Technology (Caltech). He can be reached at jmcgowan11@earthink.net

In Kepler’s time the reigning Ptolemaic theory could predict the position of Mars to within a few degrees, usually less than a one percent error. How important is such a small error? Space missions routinely depend on modern orbital dynamics, a lineal descendant of Kepler’s work, to make far more accurate calculations to succeed. The Mars Climate Orbiter mission in 1999 failed due to a tiny error. After traveling about 300 million miles, the Mars Climate Orbiter came in about 90 miles, a tiny fraction of 300 million miles, too low, burning up in the Martian atmosphere rather than aerobreaking successfully into orbit. Successful space missions, the Global Positioning System (GPS), and other modern applications depend on precision mathematical models similar to and sometimes directly descended from Kepler’s model of the orbit of Mars.

Kepler’s story is very different from the story of Galileo and it offers different lessons for today. Diverse fields ranging from astronomy and space physics to artificial intelligence are confronted with similarly complex and confusing data. A mathematical solution to an outstanding problem comparable to Kepler’s discovery could reveal long suspected connections between gravity and other forces, perhaps enabling new power or propulsion systems, enable computers to recognize objects and spoken words, or solve other problems. This article will discuss the discovery of the elliptical orbit of Mars in the context of Kepler’s time. It will also draw some lessons from Kepler and compare and contrast Kepler’s process of discovery to modern astronomy, physics, space science and engineering, including a detailed discussion of dark matter and dark energy.

Read the rest of Kepler’s New Astronomy on Scribd, where you’ll be able to download it in several formats including PDF, or click Fullscreen in the embedded document below.

PDF: Kepler’s New Astronomy.pdf

The dream search engine would search by topic, by the detailed content of the items searched, ideally finding the desired information immediately. Actual understanding of text remains a unfulfilled promise of artificial intelligence. Statistical language processing can achieve a degree of searching by topic. This article introduces the basic concepts and mathematics of statistical language processing and its applications to search. It gives a brief introduction and overview of more advanced techniques in statistical language processing as applied to search. It also includes sample Ruby code illustrating some simple statistical language processing methods.

Read the rest of Faster, Better, Cheaper Search Engines on Scribd, where you’ll be able to download it in several formats including PDF, or click Fullscreen in the embedded document below.

Source code: trigram.zip

PDF: Faster-Better-Cheaper-Search-Engines.pdf