Sunday, October 28, 2012

MSU photos 5

Autumn in East Lansing (near Lyman Briggs residential college on the MSU campus).

Senator Levin visits an MSU lab. The device they are discussing detects DNA from invasive species using a microfluidic chip.

Visit to UW Madison as part of the UW-MSU Great Lakes BioEnergy Research Center collaboration. The first building is microbiology, the second one under construction is for the Wisconsin Energy Institute which will be home to the GLBRC.

At the UW-MSU game (view from Chancellor's box). MSU won in overtime! In the next box the MSU athletic director and coaches were screaming like maniacs when MSU scored the winning touchdown. The Wisconsin fans were friendly and polite :-)

Saturday, October 27, 2012

Asian hordes in the NYT and WSJ

Stuyvesant High School (traditionally the top high school in NYC; admission is by exam) is now over 70% Asian-American. Meanwhile, at elite universities that do not practice race-blind admissions (from earlier post Demography and destiny; IIRC, currently the Asian-American fraction at all Ivies is lower than at Harvard in the early 1990s):
OCR = Department of Education's Office of Civil Rights, which conducted an investigation of anti-Asian bias in Harvard admissions around 1990.
The Chosen, p.510: ... Asian-Americans had the highest SATs of all [among groups admitted to Harvard]: 1450 out of a possible 1600. In 1991 the Asian-American/white admission ratio [ratio of percentages of applicants from each group admitted] stood at 84 percent -- a sharp downturn from 98 percent in 1990, when the scrutiny from OCR was at its peak. Though [this ratio] never dropped again to the 64 percent level of 1986, it never returned to its 1990 zenith. Despite Asian-Americans' growing proportion of the national population, their enrollment also peaked in 1990 at 20 percent, where it more or less remained until 1994. ... by 2001 it had dropped below 15 percent.
So the "subjective but fair" measures used in admissions resulted in a record high admit rate for Asians during the year Harvard was under investigation by the federal government. But mysteriously the admit rate (relative to that of white applicants) went down significantly after the investigation ended, and the overall Asian enrollment has not increased despite the increasing US population fraction of Asians.
A child of privilege:
NYTimes: Ting Shi said his first two years in the United States were wretched. He slept in a bunk bed in the same room with his grandparents and a cousin in Chinatown, while his parents lived on East 89th Street, near a laundromat where they endured 12-hour shifts. He saw them only on Sundays. ...

The afternoon his acceptance letter to Stuyvesant High School arrived in the mail, he and his parents gathered at the laundromat, the smell of detergent and the whirl of the washing machines filling the air. “Everyone was excited,” Ting recalled.
As usual the article makes a big deal about test prep. Academic studies show that test prep is of limited value in raising scores (see figure below). On the other hand, very intense study over many years probably results in actual learning. We can't have that, can we?

This WSJ article is entitled "Rise of the Tiger Nation":
WSJ: ... The subtle vying for success in various realms of American life between Asian-Americans and American Jews makes one wonder what mores and tastes will look like when Asian-Americans begin to exert their own influence over the culture. Will the verbal brio and intellectual bent of Jews, their edgy irony and frank super-competitiveness give way to Asian discretion, deference to the community, and gifts for less verbal pursuits like music, science and math? Will things become, as they once were under WASP hegemony, quieter?

Not if the mercurial nature of culture has anything to do with it. Think of the wild Korean-American comedian Margaret Cho, who belongs on the same family tree of comic art as the wild Jewish-American comedian Sarah Silverman. Jeremy Lin himself, in his video for the class of 2012 at Stuyvesant, included an antic rap song performed with an Asian-American friend. And the speaker who addressed the high school's graduates in person last June was the 32-year-old Chinese-American actor Telly Leung, a star of the hit TV series "Glee."

Mr. Leung spoke for over 20 minutes, joking, shouting, making ironic quips, teasing and provoking. At one point, he boasted that he had overthrown his parents' middle-class expectations of stability and security and made them redefine their idea of the American dream. He sounded, dare I say it, like a certain type of Jew. Which is another way of saying that he sounded like everyone who comes to America from somewhere else and ends up exemplifying, anew, a native irreverence and vitality that is as old as the American hills.

Congratulations Stuyvesant High School Class of 2012!

Friday, October 26, 2012

But is it art?

A. Zee refers me to this art exhibition of theoretical physics blackboard scribblings. The one below is from Berkeley:

Here's a shot of my whiteboard from the post Last days in Oregon.

De novo deleterious variants identified via sequencing

Genome sequencing is poised to become a routine clinical tool.
Forbes: In two papers in major scientific journals, researchers today suggested pushing DNA sequencing into more routine use in the clinic, and not just as a research tool.

Dutch researchers are proposing that DNA sequencing replace older forms of genetic tests for diagnosing the cause of severe intellectual disability, the second time in a day that researchers have pushed the emerging technology as a first-choice diagnostic test for severe illness. Those results were published this evening in the New England Journal of Medicine.

“This is the new test for intellectual disability. There is no doubt about it,” says Han Brunner of the Radboud University Nijmegen Medical Center, one of the Dutch study’s authors. “This is a paradigm shift to genome-first medicine for patients who have complex problems that will not be easy to diagnose by conventional strategies.”

Earlier today, a study in Science Translational Medicine proposed that DNA sequencing could become a standard first-choice test for infants in neonatal intensive care units, because a combination of new software and hardware could allow doctors to get results in just 50 hours, answering questions about what is making a baby sick far faster when time is of the essence.
The Dutch researchers found de novo mutations which led to severe cognitive impairment. It is almost certain that there are many more mutations which lead to smaller impairment. This is evidence that mutational load is at least a partial factor in population variation in cognitive ability. See earlier post: Deleterious variants.
NEJM: We evaluated patients with intellectual disability to exclude known causes of the disorder. We then sequenced the coding regions of more than 21,000 genes obtained from 100 patients with an IQ below 50 and their unaffected parents. A data-analysis procedure was developed to identify and classify de novo, autosomal recessive, and X-linked mutations. In addition, we used high-throughput resequencing to confirm new candidate genes in 765 persons with intellectual disability (a confirmation series). All mutations were evaluated by molecular geneticists and clinicians in the context of the patients' clinical presentation.

... We identified 79 de novo mutations in 53 of 100 patients. A total of 10 de novo mutations and 3 X-linked (maternally inherited) mutations that had been previously predicted to compromise the function of known intellectual-disability genes were found in 13 patients. Potentially causative de novo mutations in novel candidate genes were detected in 22 patients. Additional de novo mutations in 3 of these candidate genes were identified in patients with similar phenotypes in the confirmation series, providing support for mutations in these genes as the cause of intellectual disability.

... De novo mutations represent an important cause of intellectual disability; exome sequencing was used as an effective diagnostic strategy for their detection. (Funded by the European Union and others.)
Very rough numbers: suppose 30 de novo mutations per person lead to 1 in 1000 chance of cognitive impairment, so 1/30k of 3E09 bp = 1E05 bp affect cognition in a powerful way. That's 100k loci ... presumably variation at these sites is fixed in the normal population, and (normal) variation in cognitive ability is due to some smaller set of nearby loci.

Tuesday, October 23, 2012

Deleterious variants affecting traits that have been under selection are rare and of small effect

This NYTimes article discusses ideas similar to the ones in my BGA 2012 talk (slides): because of previous selection (e.g., over the last millions of years of hominid development), most rare alleles affecting intelligence will have slightly negative effect. That is, the alleles of large, positive effect (to be precise: on fitness) will be found in every "normal" person, whereas alleles of small negative effect will still linger at low frequency. Being smarter is a consequence of having fewer of these rare deleterious variants.

Note, deleterious variants are not all the result of recent mutations. Even after a long period of selection, (+) alleles are not necessarily fully fixed (Minor Allele Frequency = MAF > 0); instead one has a distribution of MAFs and (+) causal alleles for a selected trait will have a distribution peaked at 1 whereas (-) alleles will have a distribution peaked at 0. (See figures below.)
NYTimes: Few of us are as smart as we’d like to be. You’re sharper than Jim (maybe) but dull next to Jane. Human intelligence varies. And this matters, because smarter people generally earn more money, enjoy better health, raise smarter children, feel happier and, just to rub it in, live longer as well.

But where does intelligence come from? How is it built? Researchers have tried hard to find the answer in our genes.

... Kevin Mitchell, a developmental neurogeneticist at Trinity College Dublin, thinks the latter. In an essay he published in July on his blog, Wiring the Brain, Dr. Mitchell proposed that instead of thinking about the genetics of intelligence, we should be trying to parse “the genetics of stupidity,” as his title put it. We should look not for genetic dynamics that build intelligence but for those that erode it.

The premise for this argument is that once natural selection generated the set of genes that build our big, smart human brains, those genes became “fixed” in the human population; virtually everyone receives the same set, and precious few variants affect intelligence. This could account for the researchers’ failure to find many variants of measurable effect.

But in some other genetic realms we do differ widely, for example, mutational load — the number of mutations we carry. This tends to run in families, which means some of us generate and retain more mutations than others do. Among our 23,000 genes, you may carry 500 mutations while I carry 1,000.

Most mutations have no effect. But those that do are more likely to bring harm than good, Dr. Mitchell said in an interview, because “there are simply many more ways of screwing something up than of improving it.”

Open the hood of a smooth-running car and randomly turn a few screws, and you’ll almost certainly make the engine run worse than before. Likewise, mutations that change the brain’s normal development or operation will probably slow it down. Smart Jane may be less a custom-built, high-performance model than a standard version pulling a smaller mutational load. ...

Here are some relevant figures from my slides showing the effect of selection on MAF distributions. Imagine millions of years of selection causing the distribution of alleles to change as shown in figures A and B. According to my estimates (based on actual data) most humans have (order of magnitude) 1000 rare (-) alleles for intelligence and height, and someone who is one standard deviation above average has (very roughly) 30 fewer (-) variants. (See slides for more details.) A human with none of the negative alleles might be 30 SD above average! Such a person has yet to exist in human history...

Saturday, October 20, 2012

Obama's way

A glimpse into the inner Obama.
NYTimes: ... On rare occasions, Mr. Obama allows others a glimpse of the history, expectations and hope he carries with him. At the funeral of the civil rights leader Dorothy Height in 2010, he wept openly. Again and again, those close to him say, Mr. Obama is moved by the grace with which other blacks who broke the color barrier behaved under pressure.

When Ruby Bridges Hall went to see the famous Norman Rockwell portrait of her marching into school, which Mr. Obama had hung just outside the Oval Office, the president opened up a bit. The painting shows a 6-year-old Ms. Hall in an immaculate white dress walking calmly into school, a hurled tomato and a racial slur on the wall behind her.

The president asked Ms. Hall, now 58, how she summoned up such courage at that age and said he sometimes found his daughters staring at the portrait. “I really think they see themselves in this little girl,” he said, according to an interview with Ms. Hall.

“Doing the work we do, it gets really lonely,” Ms. Hall said. “I felt like we understood each other because we belong to the same club.”

The Rockwell painting:

Original photo:

I find these images deeply moving, all the more so because I have a 6 year old daughter. Can you imagine your child having to experience this?
Wikipedia: ... Former United States Deputy Marshal Charles Burks later recalled, "She showed a lot of courage. She never cried. She didn't whimper. She just marched along like a little soldier, and we're all very proud of her."

Akerloff on Efficient Markets Hypothesis

I particularly like his comments (@13 min or so) on Snake Oil and financial assets. When market participants are exuberant (overly confident) it is natural for firms to create and market new assets that are overpriced relative to actual value, or have dangerous risk-return tradeoffs. For the latest example, in natural gas drilling rights during the recent boom (now a bust), see here.

See also Venn diagram for economics.

The cover illustration of Akerloff and Shiller's book. Are there any economists outside of Chicago who still don't believe in "animal spirits"?

Friday, October 19, 2012

Dyson on philosophy and the gravitational free lunch

Freeman Dyson in The NY Review of Books:
When and why did philosophy lose its bite? How did it become a toothless relic of past glories? These are the ugly questions that Jim Holt’s book compels us to ask. Philosophers became insignificant when philosophy became a separate academic discipline, distinct from science and history and literature and religion. The great philosophers of the past covered all these disciplines. Until the nineteenth century, science was called natural philosophy and officially recognized as a branch of philosophy. The word “scientist” was invented by William Whewell, a nineteenth-century Cambridge philosopher who became master of Trinity College and put his name on the building where Wittgenstein and I were living in 1946. Whewell introduced the word in the year 1833. He was waging a deliberate campaign to establish science as a professional discipline distinct from philosophy.

Whewell’s campaign succeeded. As a result, science grew to a dominant position in public life, and philosophy shrank. ...
He also tells the story of Gamow and Einstein crossing the street:
Quantum uncertainty allows the temporary creation of bubbles of energy, or pairs of particles (such as electron-positron pairs) out of nothing, provided that they disappear in a short time. The less energy is involved, the longer the bubble can exist. Curiously, the energy in a gravitational field is negative, while the energy locked up in matter is positive. If the Universe is exactly flat, then as Tryon pointed out the two numbers cancel out, and the overall energy of the Universe is precisely zero. In that case, the quantum rules allow it to last forever. If you find this mind-blowing, you are in good company. George Gamow told in his book My World Line (Viking, New York, reprinted 1970) how he was having a conversation with Albert Einstein while walking through Princeton in the 1940s. Gamow casually mentioned that one of his colleagues had pointed out to him that according to Einstein's equations a star could be created out of nothing at all, because its negative gravitational energy precisely cancels out its positive mass energy. "Einstein stopped in his tracks," says Gamow, "and, since we were crossing a street, several cars had to stop to avoid running us down".
Gamow's statement (at least as it appears above) is not quite correct. There are zero energy compact objects in general relativity, but they are quite special and not like ordinary stars. See here and also this blog post (2007):
... years ago I wrote a paper (unpublished) showing how to obtain a zero energy configuration in GR out of massive constituents. Particle theorists I discussed it with all thought I was crazy, but the referee was a very erudite relativist, who pointed out that a similar result (using different constructions) had been obtained by ADM, Novikov and Zeldovich, and others long ago.

Thursday, October 18, 2012

Sakharov's third idea

We know that the decisive ideas for the first thermonuclear device came from Ulam and Teller. Did the great theorists Sakharov and Zeldovich (both names will be familiar to students of cosmology and particle physics) who created the Soviet H-bomb have the same ideas independently, or did they obtain them via espionage? The answer is still in dispute ...
Scientific American: ... There are no documents shedding light on this crucial period. There are only three fragments of oral history:

1. Sakharov’s close associate Yury Romanov says: “The Third Idea emerged in the spring of 1954. It began when Sakharov brought the theorists together and set forth his idea about the high coefficient of reflection of impulse radiation from the walls made of heavy material.”

2. An associate of Zeldovich, Viktor Adamskii, recollects that one day Zeldovich burst into his study and joyously exclaimed: “We should do it differently, we’ll release radiation from a spherical device!”

3. The most intriguing is the testimony of another associate of Zeldovich, Lev Feoktistov, who questioned the Soviet originality of the Third Idea. To him the Third Idea was too sudden to be truly indigenous. He says there were “neither drawings nor accurate data from the outside,” but that Sakharov and Zeldovich were bright and experienced enough to be enlightened by just a few words’ hint from a well-placed spy.

... My own reading of Sakharov’s writings suggests that he never had access to Fuchs’s report of 1948. Consider the following words in Sakharov’s memoirs, with a note he added toward the end of life:
Now I think that the main idea of the H-bomb design developed by the Zeldovich group was based on intelligence information. However, I can’t prove this conjecture. It occurred to me quite recently, but at the time I just gave it no thought. (Note added July 1987. David Holloway writes in “Soviet Thermonuclear Development,” International Security 4:3 (1979/80), p. 193: “The Soviet Union had been informed by Klaus Fuchs of the studies of thermonuclear weapons at Los Alamos up to 1946. … His information would have been misleading rather than helpful, because the early ideas were later shown not to work.” Therefore my conjecture is confirmed!)
I think the following happened. In January 1954, Sakharov was thinking about how to realize the idea of atomic compression. By May, he had realized that the flash of light from an exploding A-bomb — as opposed to the neutrons and other material products — would be the best tool to compress the thermonuclear charge. He realized that the flash of light could be confined within a metal casing for a microsecond or so, long enough to compress the charge symmetrically. He discussed this idea with Zeldovich, who recognized this as the idea he had failed to appreciate in Fuchs’s report six years earlier. As soon as he grasped Sakharov’s arguments, he (with his close associate Trutnev) brought in some details from Fuchs’s report, but never mentioned the actual report to Sakharov, since the latter was not granted access to it. So, Sakharov drew the conclusion that Zeldovich and Trutnev had also been very close to the Third Idea.
If Zeldovich was already familiar with radiation pressure as the tool for compression, via the Fuchs report of 1948, then perhaps one cannot really credit Teller so much for adding this ingredient to Ulam's idea of a staged device using a fission bomb to compress the thermonuclear fuel. Fuchs and von Neumann had already proposed (and patented!) radiation implosion years before.

Monday, October 15, 2012

Prometheus: meeting your maker

I finally got to see it over the weekend. Re: plot, there is a way to interpret the story that actually hangs together (suspension of disbelief regarding workings of Darwinian evolution that produced mankind still required, however).

This is one of my favorite scenes. Michael Fassbender is fantastic as the android David.

Some interesting stuff here:

"Please fund my startup!"

See also this old post: Prometheus in the basement.

Saturday, October 13, 2012

Soldaten: On Fighting, Killing, and Dying

Highly recommended. There were also German tapes of Allied prisoners, but those have not yet been found!

Sönke Neitzel, Professor of International History, London School of Economics, discusses his investigations into the mind-set of the German fighting man during World War II. Soldaten: On Fighting, Killing, and Dying, written with social psychologist Harald Welzer, is based on declassified transcripts of covert recordings taken within the confines of the holding cells, bedrooms, and camps that housed the German POWs, providing a view of the mentality of the soldiers in the Wehrmacht, the Luftwaffe, the German navy.
See also What it was like, specifically:
Tapping Hitler's Generals: Transcripts of Secret Conversations, 1942-1945. Farm Hall for captured German generals. Who knew what, when? More here. Those tricky Englanders!
For more on Farm Hall, where German nuclear scientists were held and secretly taped, see The Heisenberg uncertainty.

Friday, October 12, 2012

The Normaliens

In an earlier post I mentioned that Serge Harouche (2012 Nobel Prize in physics) is a normalien: a graduate of France's Ecole Normale Superieure. Admission to ENS is strictly meritocratic, based on a competitive exam. The result: 12 Nobel Prize laureates and 10 Fields Medalists from a school with fewer than a thousand undergraduates. (The school is similar in size to Caltech; smaller than most high schools.)

See Defining Merit for the story of Harvard's internal debates of the 1950's, during which a realistic and shrewd admissions dean faced down idealistic faculty committees that wanted to make Harvard more meritocratic.
"Do we want an Ecole Normale Superieure, a 'cerebral school' ... ?"

"What's wrong with Harvard being regarded as an egghead college? Isn't it right that a country the size of the United States should be able to afford one university in which intellectual achievement is the most important consideration?"

Tuesday, October 09, 2012

Schrodinger Cat Nobels

Serge Haroche and Dave Wineland share the 2012 Nobel Prize for their work in quantum optics / atomic physics. Wineland traps atoms whereas Haroche traps photons. Haroche is a normalien and Wineland was educated at Berkeley and Harvard.

My favorite Haroche experiments are the ones in which he creates macroscopic Schrodinger cat states and watches them decohere. For example, see here and here. I also like Haroche's book Exploring the Quantum.

See also Schrodinger's virus.

Sunday, October 07, 2012

My "controversial views"

Update: See this video of interview on cognitive genomics and related topics.

This Lansing State Journal article covers my recent appointment as VP of Research and Graduate studies at MSU. It's journalism, so as you can expect they emphasized potentially controversial topics like my work in genomics. (I expend about 10% of my research effort on this work, but it's much more titillating than the quantum mechanics of black holes!)

In order to set the record straight I have excerpted from the article and added my own comments.
... He is working with BGI-Shenzhen, a Chinese company that runs one of the world’s largest gene-sequencing operations, on a project to identify the genetic basis of intelligence.

The company’s leaders “just want to do science,” he said Friday during a lecture on campus. In other forums, he hasn’t shied away from talking about possible practical applications in genetically engineering a smarter population, someday allowing parents to choose the sperm and egg — or fertilized embryo — that would give them the best odds of having a high IQ kid.

“I hope that progressive governments will make this procedure free for everyone,” he wrote in July on his blog, Information Processing.

“The benefits from increased economic output, decreased welfare and criminality rates,” he added, would more than outweigh the costs.
The lecture referred to is listed here, with a link to the slides. The blog comments referred to appear here. The context is possible future technologies (in my rough estimation, genetic prediction for humans is probably 10 years out, zygote selection possibly 20 years out). This kind of discussion is also known as science fiction (we were discussing the movie Gattaca; see also here) and is a common pastime among geeky types. As I emphasized to the reporter, scientists discover new things and invent new technologies, but in a democratic society like ours it's the electorate that sets policies governing those technologies. My personal position is: IF genetic enhancement becomes possible, THEN it is better for governments to make it free rather than let it remain an option only for the rich.
Shortly after the start of classes this fall, Daniel HoSang, a professor of political science and ethnic studies at the University of Oregon, sent an email to a handful of faculty. Hsu, he wrote, “has taken a keen personal and professional interest in projects with strong Eugenicist overtones.” Because of Hsu’s position of authority at MSU, he said, he felt compelled to warn them.

His concerns were equally about positions Hsu had taken in his blog five years ago: that race is “clearly” a valid biological concept, that whether there are more-than-superficial differences between groups (in areas such as cognitive ability, personality and athletic prowess) is an open question.

Those positions aren’t outside the mainstream discourse of geneticists, though they’re not uncontested. They certainly run counter to the long-held conviction in the social sciences that race is more a social category than a biological one, formed around a distorted idea of human difference. If advances in genetic science have changed the terms of that debate, they have not ended it.

In an interview and email, Hsu said his position on the existence of significant group differences is “I don’t know” and that scientists should be incredibly careful about claiming that such differences do exist “because we have a bad history.”

He also said that, with the rapid recent advances in genetic science, he worries about the gap between what geneticists know and what everyone else does. “That is something that has to be really carefully talked about,” he said, “but we can’t talk about it if only the scientists understand the results and the social scientists refuse to actually try to understand the results.”
Then Assistant Professor HoSang once publicly stated (during a social science seminar at Oregon I attended) that he would "do everything in his power" to oppose another (Sociology) faculty member's effort to explain recent genetic results to the broader field. I found this statement so odd that it stuck in my memory. The paper that elicited the threat is published here. The story behind the publication of the paper (which took something like 4 years; I have read the actual referee reports), authored by a faculty member who has held tenured positions at both Oregon and Dartmouth, is shocking and contributed to my comments in the last paragraph above.

Genetic clustering of human populations by ancestry or geographical origin (also referred to as "population structure"; not something I work directly on) is uncontroversial in genomics. It is illustrated, e.g., here (figure from a paper in Science, obtained via a blog at Discover Magazine -- hardly hotbeds of controversy), and explained a bit more mathematically here. See also this Nature article describing Eigenstrat, a standard software tool used to correct for population structure in genetic studies (yes, it's really there -- we can't wish it away).

In response to the reporter's queries about my opinions on group differences, I wrote
As a physicist I am used to a high level of scientific rigor. Statistical certainty of 99.9% is not sufficient, in our field, to claim a discovery (e.g., a new elementary particle). Thus, the correct answer to many questions (e.g., do electrons have substructure?) is: I do not know.

In addition, I feel it is ill-advised to speculate because of our difficult history with race.

Adventures of a Mathematician

I found my copy of Ulam's book Adventures of a Mathematician recently while preparing to move (it was in a box with other books and notes from Caltech). I had not looked at it since I was an undergraduate! Below are some interesting excerpts to go with the ones I posted here.
[p.60] ... the vacancy in the Society of Fellows at Harvard which I was invited to fill resulted from Chandrasekhar's acceptance of an assistant professorship at Chicago. 
[p.81] When we talked about Einstein, Johnny [von Neumann] would express the usual admiration for his epochal discoveries which had come to him so effortlessly ... But his admiration seemed mixed with some reservations, as if he thought, "Well, here he is, so very great," yet knowing his limitations. [ See also Feyerabend on the giants. ] ... I once asked Johnny whether he thought that Einstein might have developed a sort of contempt for other physicists, including even the best and most famous ones -- that he had been deified and lionized too much... Johnny agreed... "he does not think too much of others as possible rivals in the history of physics of our epoch."
[p.107] I told Banach about an expression Johnny had used with me in Princeton before stating some non-Jewish mathematician's result, "Die Goim haben den folgenden satz beweisen" (The goys have proved the following theorem). Banach, who was pure goy, thought it was one of the funniest sayings he had ever heard. He was enchanted by its implication that if the goys could do it, then Johnny and I ought to be able to do it better. Johnny did not invent this joke, but he liked it and we started using it.
There are many more interesting things, including the story behind the Ulam-Teller design for the hydrogen bomb.

Saturday, October 06, 2012

MSU photos 4

Ford CEO Alan Mulally visits MSU.

Coach Dantonio addresses boosters shortly before the OSU game.

New Plant Biology building.

Naipaul, Tejpal and India

Tarun Tejpal interviews V.S. Naipaul. Unfortunately, at this point Tejpal is a more interesting thinker than Naipaul.

I highly recommend Naipaul's non-fiction such as his India trilogy (discussed @25:30): An Area of DarknessIndia: A Wounded Civilization and India: A Million Mutinies Now.

For a complex portrait of Naipaul, see Paul Theroux's Sir Vidia's Shadow.

Thursday, October 04, 2012

The Christy Gadget

Christy was one of the last Manhattan Project survivors.
NYTimes: Robert F. Christy, who as a young Canadian-born physicist working on the Manhattan Project came up with a critical insight that led to the creation of the world’s first atom bomb, died on Wednesday at his home in Pasadena, Calif. He was 96.

... The first bomb, developed in secrecy during World War II at Los Alamos, N.M., relied on implosion. The plan was to detonate a sphere of conventional explosives, the blast from which would compress a central ball of nuclear fuel into an incredibly dense mass; that in turn would start a chain reaction that would end in a nuclear explosion.

But the Los Alamos team discovered that the interface between the detonating explosives and the hollow sphere could become unstable and ruin the crushing power of the blast wave.

Dr. Christy, while studying implosion tests, realized that a solid core could be compressed far more uniformly, and he worked hard in the days that followed to convince his colleagues of its superiority. He succeeded, and the hollow core was replaced with one made of solid plutonium metal.

A 1993 book, “Critical Assembly,” sponsored by the Department of Energy, which maintains the nation’s nuclear arsenal, said Dr. Christy’s insight reduced the risk that the core would lose its spherical form and thus fail to explode.

And Robert S. Norris, an atomic historian and the author of “Racing for the Bomb,” called Dr. Christy’s breakthrough, known as the Christy pit, “a conservative solution to a problem they were having” that “increased the likelihood of a successful detonation.”

[ The bomb itself was called the "Christy Gadget". ]

Robert Frederick Christy was born May 14, 1916, in Vancouver and studied physics at the University of British Columbia. He was a graduate student at the University of California, Berkeley, under J. Robert Oppenheimer, a leading theoretical physicist who became known as the father of the atomic bomb.

After completing his studies in 1941, Dr. Christy worked at the University of Chicago before being recruited to join the Los Alamos team when Oppenheimer became its scientific director.

After the war, Dr. Christy joined Caltech in theoretical physics and stayed at the university for the rest of his academic career, serving as a faculty chairman, vice president, provost (from 1970 to 1980) and acting president (1977-78). He was elected to the National Academy of Sciences.
Caltech Oral History:
Then, in the examinations at the end of grade twelve, they gave us general exams — and this was given to the whole province of British Columbia ... I could get top marks in anything, in that kind of exam. So I got the highest marks on these exams of anyone in the province.

Monday, October 01, 2012

Andrew Ng and Coursera

Great profile of Coursera co-founder Andrew Ng. I first met Andrew a few years ago at Foo Camp. He attended a talk I gave on psychometrics, and we had several discussions afterwards. The formulation of g as a means of compressing cognitive data was not lost on him.

Little did I know at the time he was interested in technology applied to teaching.

Here are his popular lectures on machine learning. See also Whither higher education?
Chronicle of Higher Education: ... Today Mr. Ng is an innovator in an entirely different setting: online education. He is a founder of the start-up Coursera, which works with 33 colleges to help them deliver free online courses. After less than a year of operation, the company already claims more students—1.3 million—than just about any educational institution on the planet. Mr. Ng likes to say that Coursera arrived at an "inflection point" for the idea of massive open online courses, or MOOC's, which are designed so a single professor can teach tens of thousands of students at a time.

... "There's a certain way of thinking that many AI researchers have—it's the idea of automation," Mr. Ng explains, his lanky frame folded onto a couch in a conference room. He speaks in a quiet voice colored by a British accent—he was born in Britain and grew up in Hong Kong and Singapore—and his understated manner makes you forget that his teaching videos have been viewed hundreds of thousands of times. He is sometimes recognized as a kind of celebrity on the streets near Stanford.

"A lot of AI successes have been about automating the routine things that do not call on the highest levels of human creativity," he says, noting that spam filtering and recognizing faces in photographs can now be done deftly by software.

After teaching at Stanford for several years (he's now on leave), Mr. Ng felt that grading was eating up too much of teaching time. Computers, he thought, could step in and grade complex assignments, not just multiple-choice exams.

"I actually enjoy working through problems with students," Mr. Ng says. "What I don't enjoy is grading 400 homeworks. And so our thinking was to automate some of the grading so it frees up more faculty time for the interactions."

He put his ideas into practice about five years ago, when he started Stanford Engineering Everywhere, which offered MOOC's before anyone had heard of them.

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