Boulevard of Broken Dreams

The brilliant and tragic history of nuclear fusion

Sun in a Bottle: The Strange History of Fusion and the Science of Wishful Thinking
Charles Seife
Viking Adult, October 2008

Among all of humanity’s great quests to wrest control of nature and its own destiny, few quests have been as grand in scale and optimism as nuclear fusion. The fascinating history of nuclear fusion shows man’s relentless efforts to first understand and then gain power over the source of energy that makes the stars shine. This history has also been dotted with some of the most brilliant, colorful and tragic figures in scientific history. Most importantly, fusion also demonstrates the dangers and pitfalls inherent in trying to seize nature’s greatest secrets from her.

In this engaging and informative history, Charles Seife tells us the story of trying to put the sun in a bottle, the singular personalities which permeated this history, the monumental mistakes made in understanding and harnessing this awesome source, and the wishful thinking that has pervaded the dream ever since its conception. Seife who has bachelor’s and master’s degrees in mathematics from Princeton and is now a journalism professor at NYU does a great job of clearly explaining the science behind fusion, and sprinkles his narrative with wit and gripping human drama.

These days fusion is mostly associated with hydrogen bombs that can obliterate entire cities and populations. And yet its story begins with a quest to understand one of the oldest and most profound questions that man has pondered; what makes the sun shine? Quite early on, it was quickly recognized that chemical rections couldn’t sustain the tremendous power of the sun for so long. After many decades of efforts, it was the great physicist Hans Bethe who finally cracked the secret of the stars’ luminous glow. Bethe found out a set of reactions catalysed by carbon that achieved the transformation of four hydrogen atoms into helium atoms. This central mechanism was soon shown to underlie the production of energy in all so-called main sequence stars like the sun.

It was with the entry of the United States into the Second World War however, that a more sinister use for nuclear fusion was envisioned by the volatile, brilliant Hungarian physicist Edward Teller, a dark character whose shadow looms large over the history of fusion and nuclear weapons. Teller proposed setting off a then still conceptual atomic bomb to generate the immense temperatures of tens of millions of degrees at the center of the sun that would ignite and hopefully propagate a fusion reaction in deuterium and tritium, isotopes of hydrogen that would be easier to fuse compared to hydrogen itself. Achieving fusion is an enormously difficult endeavor; one has to overcome the intense repulsive barrier between nuclei that keeps them from approaching one other. Only temperatures of tens of millions of degrees can get these nuclei hot enough to fuse. And yet as Seife explains, there is a fundamental paradox here; the very temperatures that can overcome the repulsive barrier between nuclei also blow them apart. It seems that in achieving nuclear fusion, we are constantly working against ourselves.

The history of the US and Soviet thermonuclear weapons program has been well documented in other sources. I have a summary in my last post. Seife succintly enumerates this history and narrates the development of genocidal megaton yield hydrogen bombs which are now part of almost every nuclear arsenal.

It is however in life and not in death that fusion promises mankind eternal glory. Efforts to attain this glory bear the stamp of the quintessential Faustian bargain for knowledge, where men gambled their careers and reputations, not to mention billions of government dollars, in trying to secure their place in history and free mankind of the burden of energy sources.

These efforts, while they taught us a lot about the workings of nuclei and electrons, have been riddled with tall claims and monumental failures. Seife recounts one program after another starting in the early 1950s that promised working fusion reactors in about twenty years. In Argentina and Britain, in Russia and the United States, claims about fusion regularly appeared and were hungrily lapped up by the popular press until a few months later, when the premature optimism came crashing down in the light of further investigations. In the first UN conference organized to discuss peaceful uses for atomic energy, Indian physicist Homi Bhabha talked about fusion becoming the practical solution to all our energy needs in three decades. And yet, effort after effort exposed fundamental problems in the system, hideously recalcitrant barriers that nature seemed to have erected to thwart us in our quest. The barriers still seem insurmountable.

On one hand, grandiose schemes using hydrogen bombs to excavate harbors, to carve out canals, to analyze moon dust and to solve almost every conceivable problem were imagined by Edward Teller and his followers. None of them worked, and all of them would produce dangerous radioactive fallout. On the other hand, early on scientists recognized a basic mechanism for taming fusion; by keeping fusing deuterium or tritium nuclei confined within a magnetic field in an extremely hot plasma of electrons and nuclei. The field of plasma physics emerged. This is the famous inertial confinement approach for harnessing fusion. This approach was developed and tested throughout the 50s and 60s. Some schemes looked as if they were working. Later it was found that not only were they producing less energy than what went in, but sometimes fusion was not even taking place and the neutrons that are a signature of the process were coming from elsewhere. The first condition, a net gain of energy, is called breakeven and is a fundamental condition for any energy-generating source to be satisfied. You have got to get more energy than what you put in. Ever since then, fusion has been achieved on smaller scales, but breakeven has never been attained.

Apart from inertially confined plasma fusion, Seife also describes the second major approach called laser fusion, which gradually arose as a competitor to plasma fusion in the 1970s. In this process, intense lasers shine on a small pellet of a deuterium or tritium compound from many directions. In the center of the pellet where unearthly temperatures and pressures are achieved, fusion takes place. This approach has been pursued in many grand schemes. One is called Shiva and involves 20 laser beams from 20 different directions squeezing a fusile pellet. The latest approach is called Nova which uses even more lasers. Both Shiva and Nova are closely guarded secrets. A computer program called LASNEX which helps their operation by simulating different fusion scenarios based on hundreds of variables and conditions is highly classified. Billions of dollars were spent on both these developments. And yet, as practical energy producing devices, both Shiva and Nova now look like dead ends.

Why is this the case? Why has almost every attempt to tame fusion failed? The answer has to do simply with the magnitude of the problem, and with how less we still understand nature. Both laser fusion and inertial fusion suffer from some fundamental and extremely complex problems that were discovered only when the experiments were underway. One problem has already been stated; the difficulty of confining such a hot plasma of particles. Another problem has to do with instability. As a hot plasma of deuterium and tritium circulates in an intense magnetic and electric field, local inescapable defects and asymmetries in the fields get quickly amplified and cause ‘kinks’ in the flow. The kinks gradually grow bigger like cracks in weak concrete and finally bring the entire structure down, quickly dissipating the plasma and halting fusion. While impressive progress has been made in controlling the fine parameters of the magnetic and electric fields, the problem still persists because of its basic nature. The other problem was that the electrons were getting heated much faster than the nuclei so that the nuclei- the real target- would stay relatively cool. A third serious problem was the initiation of Rayleigh-Taylor instabilities, little whirlpools and tongues that develop when a less-dense material presses against a more-dense material. Interestingly it’s Rayleigh-Taylor instabilities and not gravity that is the reason why water from an overturned glass escapes. Rayleigh-Taylor instabilities developed in laser fusion when less dense photos of light tried to compress a denser pellet of deuterium. These instabilities quickly destroyed the fine balance of the fusion process. The process is exquisitely sensitive to the finest of defects, like nanoscopic dimples of the surface of the pellet. Solving this problem requires the best of physics and engineering.

All these problem still plague fusion, and billions of dollars, thousands of brilliant scientists and hundreds of innovative ideas later, fusion still remains a dream. It has been achieved many times, neutrons have been observed, but breakeven still is a land that’s far, far away.

But scientists don’t give up. And while legitimate scientific efforts on the two ‘hot fusion’ approaches continue, there have been cases where some scientists believed they were observing fusion a tad too easily under circumstances that were too good to believe. These events saw their careers being destroyed and the promise of fusion again mangled. The events refer to the infamous cases of ‘cold fusion’ which constitute the last and most important part of Seife’s book. Seife weaves a riveting tale around these events, partly since he was a participant in one of the debacles.

The story of Pons and Fleischmann’s 1989 cold fusion disaster at the University of Utah is well known. The two took the unusual step of announcing their results in a press conference before getting them peer-reviewed and published. Later their experiments were shown to be essentially irreproducible. Seife recounts in details the developments that gradually cast a black cloud over this claim. One of the characters in this story is Steve Jones, a physicist who has recently gained notoriety for becoming a 9/11 denier.

But I was particularly interested in the next story since I had actually met and talked to one of the characters in the cold fusion catastrophe many years ago. Rusi Taleyarkhan, an Indian scientist, happened to come to our University in 2002 to give a talk. Just a few months before, he and his colleagues had published a paper in the prestigious journal Science, which if true would herald one of the greatest breakthroughs in scientific history. Taleyarkhan and his group claimed to have observed fusion in the most disarmingly simple experiment. They had taken a solution of deuterated acetone (acetone with its hydrogen atoms replaced by deuterium) and had bombarded it with neutrons that caused giant bubbles to form in the solution. They had then exposed the solution to intense acoustic waves, thus causing the bubbles to violently collapse. The phenomenon was well known and is called sonoluminescence, a name alluding to the light that is often given off because of these violent collapses. But what was Taleyarkhan’s claim? That the immense pressures and temperatures generated at the center of the bubbles caused nuclear fusion of the deuterium in the acetone, essentially in a tabletop apparatus at room temperature. Why acetone? This was the question I asked Taleyarkhan when I met him in 2002. He did not know, and he sounded sincere about it.

But this was before the storm was unleashed and the controversy erupted. In this case unlike the previous one, the work had been peer reviewed by one of the most famous and stringent journals in the world. But curiously, further investigation by Seife and others revealed that the paper had been published by Science’s editor in spite of objections by the reviewers. This was highly unusual to say the least. What was more disturbing was that concomitant experiments done at Oak Ridge National Laboratory, Taleyarkhan’s home turf at the time, revealed negative results. Once the results were announced, researchers across the world including some at prestigious institutions scurried around to repeat the experiments using more sophisticated detectors and apparatus. Fusion produces very signature neutrons of specific energy. The more sophisticated apparatus failed to detect these neutrons. In the earlier cold fusion debacle, there had been doubt about the energy peaks of the neutrons. Similar doubts started surfacing in this case. Questions were also raised about the possibly shoddy nature of the experiments, including the absence of control experiments. Later Taleyarkhan moved to Purdue, and Purdue initially defended the experiments. But the story remained murky. Some ‘independently’ published later articles turned out to not be so independent after all. Gradually, just like it had previously, the great edifice turned into a crumbling structure and came down. As a reporter for Science then, Seife personally covered these events. Purdue reinvestigated the matter and as of 2008, Taleyarkhan is forbidden from working as a regular PhD. student advisor at Purdue. Even though he was not convicted of deliberate fraud, his reputation has come crashing down.

This then is the history of fusion, episode after episode of wishful thinking to solve the biggest problem in the history of mankind. A fusion reactor may someday be possible, but nothing until now suggests that it would be so. It’s hard to trust a technology if it has consistently failed to deliever on its promise time after time. After all this, even the mention of the statement ‘cheap, abundant and universal energy’ should raise our eyebrows. In the afterword, Seife discusses the rather harsh nature of the scientific process where skepticism is everyone’s best friend and results are intensely vetted, a fact that’s necessary though to keep science and scientists in line. Fusion seems to be one of those endeavors where tall claims have been more consistently proclaimed than perhaps in any other branch of science. This has been undoubtedly so because of the earth-shattering implications of a true practical nuclear fusion reactor and the fame that it will bring its inventor. Even with such a reactor, our problems may not be over. First of all fusion is not as clean as it is made out to be; copious amounts of neutrons, gamma rays and other forms of radiation are released in the process. Secondly, even with mass production fusion reactors may cost no less than tens of millions of dollars. Even as Seife writes, the world’s economies have pooled their resources together into ITER, an international thermonuclear project that promises to be the biggest of its kind until now. The United States did not support the project earlier and it had to be scaled back. Now the US seems to be contributing again to a more modest version of the vision. As with other matters, the politics of fusions seems to be even more elusive than the science of fusion. Gratifyingly, Seife thinks that our best current bet to solve the energy problem is nuclear fission. It emits no carbon dioxide, provides the biggest bang for your buck, and most importantly unlike fusion is already here. Compared to the will-o-wisps of fusion, the very real strands of fission can solve many of our real problems. Ironically, controlled fusion is still a distant dream while very tangible thermonuclear bombs sit securely in the arsenals of so many nations.

In the end, one factor which Seife should have appreciated more in my opinion is the immense knowledge that has been gained from so many years of fusion research. That is one of the great virtues of science, that even failed endeavors can contribute key insights into the workings of nature and uncover new principles. Fusion might be wishful thinking, a grandiose and tragic scheme to put the sun in a bottle, but science always wins. And if not for anything else, for that we should always be grateful.

The H-Bomb Fuchs?

And a very brief history of the US hydrogen bomb effort

How the Soviets got the H-bomb by 1955 has always been something of a mystery. Although they had top-notch scientists like Andrei Sakharov working for them, they still got almost exactly the same design as the Americans in just 4 years. Nobody denies Sakharov's tremendous contributions to the H-bomb effort. And yet the question lingers whether espionage helped H-bomb design just as it had helped Soviet A-bomb design, most famously through Klaus Fuchs's efforts.

Now a new book due to be released in January claims that the authors have uncovered a spy who gave details about the H-bomb design to the Soviets. 'The Nuclear Express' is co-authored by Thomas Reed, a former weapons designer who worked at Los Alamos for many years. The authors would not name the spy since he is now purportedly dead. Historians who have weighed in don't find the idea entirely implausible; after all it is hard to believe that security would have been so tight so as to completely preclude espionage. In addition even after Fuchs was apprehended, the Soviets still had a web of spies and sympathizers spread throughout the US that even as of now is not completely deciphered.

It is worthwhile at this point to recapitulate some of the US H-bomb history:

1942: Edward Teller, the 'father of the hydrogen bomb', builds upon a suggestion by Enrico Fermi and proposes the first design for a thermonuclear weapon. This is during a secret conference at Berkeley organized by Robert Oppenheimer that's supposed to explore the feasibility of a fission weapon, not a fusion device. Teller's basic idea is to use the extreme temperatures arising from an atomic bomb to ignite a cylinder of deuterium or tritium at one end, with the unproven assumption that the fusion fuel will ignite and continue to burn, thus producing a tremendous explosion equivalent to millions of tons of TNT. The H-bomb distracts the participants enough for them to speculate on its workings, but atomic bomb design (necessary for initiating a fusion reaction anyway) is wisely given priority. The as yet speculative thermonuclear weapon is christened "The Super". The Manhattan Project is kicked off. Throughout the war Teller goes off on his own H-bomb trajectory, often contributing to flared tempers and inadequate expertise at Los Alamos.

1946: After the war, Teller who is still obsessed with the weapon convenes a short, top secret conference. Klaus Fuchs is one of the participants. The conference concludes, mostly based on Teller's optimistic assessment, that The Super is feasible. At the end of the conference, Teller submits an overly optimistic report much to the chagrin of Robert Serber, an accomplished physicist who had been Oppenheimer's principal assistant at Los Alamos. Fuchs transmits the information from this conference to the Soviets.

August 1949: The Soviets detonate their first atomic bomb. Everyone is shocked, perhaps unnecessarily so. A high-level committee headed by Oppenheimer convenes in October on Halloween and debates H-bomb development. The almost unanimous opinion is that the H-bomb is not a tactical weapon of war but a weapon of genocide and therefore its development should not be undertaken. Priority should be given instead to the development of better, tactical fission weapons.

December 1949-January 1950: Edward Teller, spurred on by the Soviet A-bomb, starts recruiting scientists to join him at Los Alamos to work on the Super. Hans Bethe initially agrees, then after a chat with Oppenheimer and Victor Weiskopf, declines. Teller blames his change of mind on Oppenheimer. Later Bethe decides to work at Los Alamos only as a consultant, mainly because he wants to prove that The Super won't be feasible.

During this time, Stanislaw Ulam and Cornelius Everett at Los Alamos embark on a set of tedious calculations to investigate the feasibility of The Super. The result is decidedly pessimistic. The Super would need much more tritium, an extremely rare and expensive isotope, to initiate burning. Even if tritium is added the probability of successful propagation is extremely low. Teller's dream is dead in the water. Fermi, one of Teller's role models, confirms the bad news.

January-February 1950: Even as Ulam's calculations give a fit to Teller, Klaus Fuchs confesses his espionage. The country gradually starts descending into a state of paranoia. Against the advice of many experts, President Harry Truman initiates a crash program to build the H-bomb. Incidentally his announcement comes before that about Fuchs. And it comes absurdly even as Ulam and others have proven that Teller's Super would not work.

1950: Throughout 1950 the options for the Super keep on looking bleaker. In June the Korean War begins, fueling more feeling of paranoia. Teller's mood blackens. At one point after Ulam reports his latest set of calculations, Teller is said to be "pale with fury"

December 1950-January 1951: Ulam makes a breakthrough. He realizes that separating the fission weapon and fusion fuel and using the extreme pressures generated by the fission weapon will cause compression of the fusion fuel, thus dramatically increasing the odds of thermonuclear burning. Ulam floats the idea to Teller who enthusiastically espouses it and also crucially realizes that radiation from the fission "primary" would do an efficient job of compressing and sparking off fusion in the fusion "secondary". The idea is so elegant that Oppenheimer calls it 'technically sweet' and now supports the program. Bethe agrees to work on the device because suddenly everyone thinks that the Soviets will now not be long in discovering it. Later, Teller makes significant efforts to discredit Ulam's role in the invention. But the Teller-Ulam design becomes the basis for almost every hydrogen bomb in the arsenals of the world's nuclear powers.

1951-1952: Work proceeds on a thermonuclear weapon. In November 1952 the world's first hydrogen bomb, Ivy Mike, explodes with a force equivalent to 650 Hiroshima type bombs. Mankind has finally invented a device that comes closest to being a weapon for complete annihilation of nations.

So that is where matters stood in 1952. That gives the spy a window of two years or so to transmit the information. It's instructive to note that after Fuchs was outed, Oppenheimer actually hoped that he had told the Soviets about the H-bomb design from the 1946 conference, since that design had been shown to fail and would have led the Soviets on a wild goose chase. However the initial thoughts that Bethe, Oppenheimer and others had about the Soviets discovering the Teller-Ulam mechanism soon don't look unfounded to me. There were experts who thought that the idea of using compression and radiation to ignite and burn the thermonuclear fuel would occur to anyone who had thought hard and long about these matters. Niels Bohr thought that a bright high-school student would have thought about it, but that's probably going a little too far. The truth could well be in between, with both original thought and espionage playing a role. In any case the new book promises fresh fodder for atomic aficionados and I have pre-ordered it.

Turning a false-positive into an active

People who deal with molecular recognition are well aware of what difference a small modification to a molecule can make. Just today I was attending a talk by a chemist who binds small molecules to RNA aptamers. He showed an aptamer that binds theophylline with 10,000 fold more affinity by caffeine- a huge difference in binding affinity for a molecule differing by only one methyl.

So it is also for medicinal agents, as demonstrated below for an example from the cited study. People who do screening must always have this nagging doubt about false positives; what if there is only a slight modification to a false positive that will convert it into an active?



Bill Jorgensen's group has done a similar study for an anti-RT HIV inhibitor. He first did similarity searching with the Maybridge library based on six known NNRTI inhibs of RT. Based on this, he found a couple of molecules in the library which he then docked into the active site of RT using the program GLIDE. Along with the six known inhibitors which scored at the top as binders, he also found one from the library. GLIDE had already been benchmarked by reproducing known crystallographic conformations.

However, when they tested this GLIDE ranked molecule against HIV, it was disappointingly inactive. On the other hand, perhaps, since GLIDE had docked it up there with the known actives, there might be a small modification that one could make to it which would inject some activity in it? Jorgensen's group used a program that they have developed named BOMB, which basically docks a molecule in an active site, and then grows appendages to it to see if it would make a difference in the binding affinity. BOMB tried out combinations of different groups on the phenyl ring of the molecule, scored the resulting structures using its energy function, and finally settled on one particular modified structure- also filtered by logP values and other Lipinski considerations- that eventually gave an IC50 of 300 nM. Not a fantastic number, but good enough to pursue as a lead.

Also noteworthy in the paper is a short discussion of another publication where a similar structure was published. According to the authors, the other authors assayed the wrong compound. Heh.

Reference:
From Docking False-Positive to Active Anti-HIV Agent
Gabriela Barreiro, Joseph T. Kim, Cristiano R. W. Guimarães, Christopher M. Bailey, Robert A. Domaoal, Ligong Wang, Karen S. Anderson, and William L. Jorgensen
Web Release Date: 06-Oct-2007; (Article) DOI: 10.1021/jm070683u

Analogies between analogies: The character of Stan Ulam

Derek's post about metaphors and analogies reminded me of a quote by a remarkable mathematician whose name is known only to aficionados now, but who stands in the front rank of brilliant mathematicians and physicists of the twentieth century- Stanislaw Ulam. Here's a quote from him about analogies:

"Great scientists see analogies between theorems or theories. The very best ones see analogies between analogies"

Indeed. And Stan Ulam could very well put himself into the second category, although his modest nature would have not made him do so.

Ulam was born in Poland and grew up in a romantic time in the 20s and 30s, when great discoveries in mathematics and physics were being made in small, enchanting roadside cafes by small groups of people working intensely together. One of those, the Scottish Cafe in Lwow, Poland, was a focal point for meeting of great minds, the best pure mathematicians in Europe. Equations used to be scribbled on tables there, and the waiters were told never to erase them. Marathon sessions used to be common, fueled by black coffee, and interrupted only by occasional meals and trips to the bathroom; one non-stop session lasted 17 hours. The mathematician Rota said this about Ulam's fascinating mind:

"Ulam's mind is a repository of thousands of stories, tales, jokes, epigrams, remarks, puzzles, tounge-twisters, footnotes, conclusions, slogans, formulas, diagrams, quotations, limericks, summaries, quips, epitaphs, and headlines. In the course of a normal conversation he simply pulls out of his mind the fifty-odd relevant items, and presents them in linear succession. A second-order memory prevents him from repeating himself too often before the same public."

Ulam was invited to visit the US as a lecturer several times during the 1930s by his fellow famous emigre from Europe, and admittedly the smartest man of his generation; John Von Neumann. Within a short time, the romantic days were at a tragic end. Ulam held out in Poland much longer than many other brilliant European scientists and mathematicians, and in 1939, on the eve of World War 2, escaped to America with his brother Adam. The rest of the Ulam family perished in the Holocaust.

After coming to the US, Ulam was secretly invited to join the Manhattan Project in Los Alamos, where he was known to be a problem solver and jovial team worker. In Los Alamos, he tried to recreate the idyllic atmosphere of his young years in Europe by installing a coffee machine outside his office where scientists could talk shop. You can get to see Ulam in The Day after Trinity. Here is a photo of three prodigies from those days, (From L to R) Ulam, Richard Feynman, and John Von Neumann

While at Los Alamos, Ulam made what was probably the most important contribution of his career- the Monte Carlo method, a way of calculating the result of complex processes through random numbers. This method is now so important and deep-rooted in physics, chemistry, and engineering, that many students have forgotten that somebody invented it. The method is now implemented as a black box in many computer programs, such as those which I use for calculating the structure of organic molecules, and so people tend to sometimes use it without knowing that they are using it.

In 1946, Ulam suffered an attack of encephalitis; he could not remember events after the attack, and after the operation, federal agents asked him questions to make sure that he may not have given away atomic secrets during his loss of recollection. After the operation, Ulam seemed to some to become even more brilliant than he had been before.

However, Ulam probably became best-known to a greater audience through his participation in the development of the hydrogen bomb. After the war, he and fellow scientist Cornelius Everett embarked on a series of tedious calculations to prove that the then accepted and widely touted design of the hydrogen bomb would not work. This was a significant result, as President Harry Truman had been earlier prodded to announce a crash effort to develop the bomb based on this design. WIthin a short time however, Ulam came to the essential breakthrough that encouraged the infamous Edward Teller to develop the most widely used design of the h-bomb. The breakthrough involved separating the fission and fusion parts of the weapons, and using compression from the fission bomb to activate the fusion bomb. After this design was invented, everybody assumed that the Soviets were doing it too, and the program was purused with vigour. Every country afterwards that developed thermonuclear weapons has used this so-called "Teller-Ulam" design or a variant of it.

The imperious Teller essentially took much of the credit for the invention, and later tried to expunge Ulam's name from that part of history. Hans Bethe liked to joke that Ulam was really the "father of the h-bomb" while Teller was the mother since he carried the baby for so long. Ulam for his own part, an unassuming and docile man, stayed away from these disputes, when he rightly could have done more for asserting his claim to fame. Ulam and Teller parted ways after the discovery, Ulam returning to his world of pure science, and Teller becoming increasingly belligerent and disliked by his fellow scientists, and pushing for new and "better" nuclear weapons, thus becoming what Richard Rhodes calls the "Richard Nixon of American science". Till the end of his life in 2004 at the age of 95, he gave hawkish and wrong advice to Presidents (famously about "Star Wars" to Ronald Reagan) and believed that he was doing the right thing in advancing peace by building more hydrogen bombs.

During his professional career, Ulam spent time at the Universities of Wisconsin, UCLA, and Boulder. His wife, Francoise, was always a loving support as well as an admirer of him. She remembers one defining moment from their lives, when she found her husband staring out the window after he had had the idea for a successful hydrogen bomb. "I have just discovered the idea that will change history", he presciently said.

Ulam died in 1984. An astonishingly versatile scientist, he had been equally at home with the most abstruse reaches of set theory and with the details of thermonuclear fusion. His memoirs, Adventures of a Mathematician, paints a fascinating and delightful portrait of the golden age of physics and mathematics, as well as the dawn of the nuclear age. In this book, we get to hear anecdotes about famous mathematicians and physicists, many of whom were good friends of Ulam.

Ulam once said:

"It is still an unending source of surprise for me how a few scribbles on a blackboard or on a piece of paper can change the course of human affairs."

Ulam was certainly one of the select few who scribbled.