Thursday, January 30, 2020

Steven Broglio on Concussions, Football and Informed Choice - Manifold Podcast #31



Steve and Corey talk with Steven Broglio, Director of the Michigan Concussion Center, about concussion risk, prevention and treatment. Broglio describes how the NCAA emerged from the deaths that almost led Theodore Roosevelt to outlaw college football. He also explains recent findings on CTE, why females may be at greater concussion risk, and why sleep is critical to avoiding long-term brain injury. They discuss how new rules probably make football safer and debate why New England is so down on kids playing football. Steve wonders whether skills are in decline now that some schools have eliminated “contact” in practices.

Steven Broglio (Faculty Profile)

Michigan Concussion Center

NeuroTrauma Research Laboratory

NCAA-DoD Grand Alliance: Concussion Assessment, Research, and Education (CARE)


man·i·fold /ˈmanəˌfōld/ many and various.

In mathematics, a manifold is a topological space that locally resembles Euclidean space near each point.

Steve Hsu and Corey Washington have been friends for almost 30 years, and between them hold PhDs in Neuroscience, Philosophy, and Theoretical Physics. Join them for wide ranging and unfiltered conversations with leading writers, scientists, technologists, academics, entrepreneurs, investors, and more.

Steve Hsu is VP for Research and Professor of Theoretical Physics at Michigan State University. He is also a researcher in computational genomics and founder of several Silicon Valley startups, ranging from information security to biotech. Educated at Caltech and Berkeley, he was a Harvard Junior Fellow and held faculty positions at Yale and the University of Oregon before joining MSU.

Corey Washington is Director of Analytics in the Office of Research and Innovation at Michigan State University. He was educated at Amherst College and MIT before receiving a PhD in Philosophy from Stanford and a PhD in a Neuroscience from Columbia. He held faculty positions at the University Washington and the University of Maryland. Prior to MSU, Corey worked as a biotech consultant and is founder of a medical diagnostics startup.

Monday, January 27, 2020

Robert Christy and Nuclear Electromagnetic Pulses (EMP)


I always wondered who first worked out the theory of Electromagnetic Pulses (EMP) produced by nuclear weapons. That an EMP would result from a nuclear explosion was known from the beginning:
During the first United States nuclear test on 16 July 1945, electronic equipment was shielded because Enrico Fermi expected the electromagnetic pulse. The official technical history for that first nuclear test states, "All signal lines were completely shielded, in many cases doubly shielded. In spite of this many records were lost because of spurious pickup at the time of the explosion that paralyzed the recording equipment."[2] During British nuclear testing in 1952–1953, instrumentation failures were attributed to "radioflash", which was their term for EMP.
But it's far from obvious that: prompt gamma rays from the nuclear explosion lead to Compton effect ionization, and the resulting Compton current interacts with the Earth's magnetic field to produce coherent synchrotron radiation forming a dangerous EM pulse.



From Achieving the Rare: Robert F. Christy's Journey in Physics and Beyond:
During Cold War years in the 1950’s, a number of mysterious communication disruptions occurred. It was feared that the communications had been sabotaged in some way by the Soviet Union. Robert was at Caltech at the time, but was also a consultant for the Rand Corporation, and became aware of this phenomenon.

For years Robert had been outspoken in his opposition to atmospheric testing of nuclear weapons, and had put a good deal of effort into understanding the effects. At that time the U.S. was still performing atmospheric tests of nuclear weapons. One test involved exploding an atomic bomb at a very high altitude, roughly 20 miles.

It had been known that atomic bombs could sometimes cause problems with electronics in the vicinity, but it was Robert who single-handedly worked out the physics by which atomic explosions in the upper atmosphere would produce an electromagnetic pulse (EMP) that could have catastrophic effects on circuits on the ground at very great distances, and could thereby disrupt communications. He was thus the first to connect the disruption of communications with the high- altitude nuclear explosions. He wrote this up as a classified report. It should be noted, however, that the warning in this report did not prevent the U.S. from carrying out the very-high-altitude “Starfish Prime” test of 1962. In this test a 1.4 megaton bomb was exploded over the Pacific Ocean at an altitude of 250 miles, causing electrical damage in Hawaii (about 900 miles away). The Soviets conducted similar high-altitude tests over Kazakhstan in the same year. These caused even more extensive damage since they were above an inhabited area rather than over the ocean.

The EMP effect of high-altitude atomic explosions is now widely known, but it was Robert Christy who first brought this phenomenon to the attention of the U.S. government. ...

[ See also articles by Longmire and Pfeffer. Perhaps the Soviets were ahead of Christy? Kompaneets, A. S., Radio Emission from an Atomic Explosion, Institute for Chemical Physics, Academy of Sciences, USSR, Journal of Experimental and Theoretical Physics (USSR), English translation in volume 35, 1538-1544 (December 1958); Original article in Russian in JETP, 8, 1076-1080 (1954). ]
The first implosion atomic bomb (Fat Man) was known as the Christy Gadget:
... 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.

... 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.

Saturday, January 25, 2020

Wuhan Coronavirus

[ See update: COVID-19 Notes or use the search label Epidemics.]


The Wuhan coronavirus outbreak (see WHO resource) caused me to look back at a paper I wrote in 2003 with A. Zee. We were motivated at the time by the recent SARS outbreak. Some results in the paper may be relevant today.

For Wuhan coronovirus the important parameters such as R0 (average number of secondary cases caused by a single infected individual) and lethality are still to be determined.
Global Spread of Infectious Diseases (ArXiv)

S. Hsu, A. Zee

We develop simple models for the global spread of infectious diseases, emphasizing human mobility via air travel and the variation of public health infrastructure from region to region. We derive formulas relating the total and peak number of infections in two countries to the rate of travel between them and their respective epidemiological parameters.
From the conclusions:
One interesting conclusion from our models is that typical international mobility – the probability per unit time of international travel for a given infected individual, estimated at mi→j ∼ 10−5 per week – is still sufficiently small that a country with well-developed public health infrastructure (effectively, a negative eigenvalue λ) can resist an epidemic even when other more populous countries experience complete saturation. In the quasi-realistic simulation 1 (figures (1),(2)), of order 10^5 infections occur in country 2, even though the disease has swept completely through country 1. In reaching this conclusion, we kept the mobility parameter fixed during the outbreak, and did not assume any draconian quarantine on international travelers arriving in country 2. Such measures would reduce the number of infections in country 2 considerably. Of course, this conclusion assumes that the public health infrastructure in country 2 remains robust during the outbreak. In the nonlinear simulation 3 (figures (6), (7)), we see that a breakdown in the medical system can lead to grave consequences.

Thursday, January 23, 2020

Barbara O’Brien on Race, Reform and Wrongful Conviction Rate Estimates



Our guest, Professor Barbara O’Brien, explains why we don’t know much about conviction error other than in murder cases. She explains factors that contribute to wrongful convictions, including mistaken cross-racial identification in sexual assault cases. Barbara also talks about the surprising frequency of “rain damage” to evidence rooms and why Texas leads the way in both executions and criminal justice reform. The two consider why having your death sentence commuted to life in prison means you are actually less likely to ever be released.

[ Note I was away when this episode was recorded so it's just Corey and Barbara. ]

Transcript

Barbara O'Brien (Faculty Profile)

The National Registry Of Exonerations



man·i·fold /ˈmanəˌfōld/ many and various.

In mathematics, a manifold is a topological space that locally resembles Euclidean space near each point.

Steve Hsu and Corey Washington have been friends for almost 30 years, and between them hold PhDs in Neuroscience, Philosophy, and Theoretical Physics. Join them for wide ranging and unfiltered conversations with leading writers, scientists, technologists, academics, entrepreneurs, investors, and more.

Steve Hsu is VP for Research and Professor of Theoretical Physics at Michigan State University. He is also a researcher in computational genomics and founder of several Silicon Valley startups, ranging from information security to biotech. Educated at Caltech and Berkeley, he was a Harvard Junior Fellow and held faculty positions at Yale and the University of Oregon before joining MSU.

Corey Washington is Director of Analytics in the Office of Research and Innovation at Michigan State University. He was educated at Amherst College and MIT before receiving a PhD in Philosophy from Stanford and a PhD in a Neuroscience from Columbia. He held faculty positions at the University Washington and the University of Maryland. Prior to MSU, Corey worked as a biotech consultant and is founder of a medical diagnostics startup.

Saturday, January 18, 2020

Certainties and Uncertainties in our Energy and Climate Futures: Steve Koonin



This is a recent (2019) talk which gives a good overview of current climate science. Speaker is Steve Koonin, formerly Undersecretary for Science, US Department of Energy (Obama administration), Caltech Provost and theoretical physicist.

See earlier post Epistemic Caution and Climate Change (including comments).

My own views (consistent, as far as I can tell, with what Steve says in the talk):
1. Evidence for recent warming (~1 degree C) is strong.

2. There exist previous eras of natural (non-anthropogenic) global temperature change of similar magnitude to what is happening now.

3. However, it is plausible that at least part of the recent temperature rise is due to increase of atmospheric CO2 due to human activity.

4. Climate models still have significant uncertainties. While the direct effect of CO2 IR absorption is well understood, second order effects like clouds, distribution of water vapor in the atmosphere, etc. are not under good control. The increase in temperature from a doubling of atmospheric CO2 is still uncertain to a factor of 2-3 and at the low range (e.g., 1.5 degree C) is not catastrophic. The direct effect of CO2 absorption is modest and at the low range (~1 degree C) of current consensus model predictions. Potentially catastrophic outcomes are due to second order effects that are not under good theoretical or computational control.

5. Even if a catastrophic outcome is only a low probability tail risk, it is prudent to explore technologies that reduce greenhouse gas production.

6. A Red Team exercise, properly done, would clarify what is certain and uncertain in climate science.

Simply stating these views can get you attacked by crazy people.
Please tell me what is implausible about the following scenario: IPCC latest report has as its central projection a ~1.5 degree C warming over the next decades, assuming CO2 production continues at current levels. During those decades, battery technology could improve by an order of magnitude, due to intense R&D efforts. Solar energy cost and efficiency could also improve significantly over the same period. If these technological advances are realized by, e.g., 2040, we could substantially decrease our carbon footprint without wholesale dislocation of the world economy. It seems that huge R&D investment (nevertheless totally negligible relative to GDP or, e.g., military spending) in alternative energy and storage technologies is a no brainer...

Koonin rebuts some criticisms of his talk.

Thursday, January 16, 2020

Sebastian Junger: Meaning from War and Technological Isolation in America - Manifold #29



This conversation occurred just after President Trump withdrew US forces from Northern Syria. Steve, Corey and Sebastian debate ISIS and the Kurds. Sebastian argues that men who went to war after 9/11 wanted to experience communal masculinity, as their fathers and grandfathers had in Vietnam and WWII, a tradition dating back millennia. When they came home, they faced the isolation of affluent contemporary American society, leading to high rates of addiction, depression, and suicide. War veterans in less developed countries may be psychologically better off, supported by a more traditional social fabric.

Transcript

Sebastian Junger

Tribe: On Homecoming and Belonging (Book)

War (Book)

Hell on Earth (Trailer)

Restrepo (Trailer)


man·i·fold /ˈmanəˌfōld/ many and various.

In mathematics, a manifold is a topological space that locally resembles Euclidean space near each point.

Steve Hsu and Corey Washington have been friends for almost 30 years, and between them hold PhDs in Neuroscience, Philosophy, and Theoretical Physics. Join them for wide ranging and unfiltered conversations with leading writers, scientists, technologists, academics, entrepreneurs, investors, and more.

Steve Hsu is VP for Research and Professor of Theoretical Physics at Michigan State University. He is also a researcher in computational genomics and founder of several Silicon Valley startups, ranging from information security to biotech. Educated at Caltech and Berkeley, he was a Harvard Junior Fellow and held faculty positions at Yale and the University of Oregon before joining MSU.

Corey Washington is Director of Analytics in the Office of Research and Innovation at Michigan State University. He was educated at Amherst College and MIT before receiving a PhD in Philosophy from Stanford and a PhD in a Neuroscience from Columbia. He held faculty positions at the University Washington and the University of Maryland. Prior to MSU, Corey worked as a biotech consultant and is founder of a medical diagnostics startup.

Thursday, January 09, 2020

Zach Hambrick on Psychometrics and the Science of Expertise -- Manifold Podcast #28



MSU Psychology Professor Zach Hambrick joins Corey and Steve to discuss general cognitive ability, the science of personnel selection, and research on the development of skills and expertise. Is IQ really the single best predictor of job performance? Corey questions whether g is the best predictor across all fields and whether its utility declines at a certain skill level. What does the experience of the US military tell us about talent selection? Is the 10,000 hour rule for skill development valid? What happened to the guy who tried to make himself into a professional golfer through 10,000 hours of golf practice?

Transcript

Science of Expertise

Zach Hambrick (Faculty Profile)

Armed Services Vocational Aptitude Battery

Project 100,000 (1960s DoD Program)

Test Validity Study Report (CLA)

The Validity and Utility of Selection Methods in Personnel Psychology

Tuesday, January 07, 2020

Manifold #27 Bonus Content: Left and Right Student Bloggers at MSU

This is bonus content related to our interview with Professor Andrew Hartman, The Culture Wars Then and Now (Manifold Podcast #27).



Steve and Corey talk about political polarization and bias on campus with student editors of MSU’s dueling political blogs. The left-leaning students argue that the media has blown controversies over student politics out of proportion, while the conservative writers maintain that they do not feel comfortable expressing their views in many classes. Corey asks how beneficial is it to be white in America? Is the University as bastion of open debate no longer viable, especially in the current economic environment?

Transcript.

Sunday, January 05, 2020

Rule Britannia


Dom has seized the controls, but now has to operate the giant robot.

This is a unique situation: someone who understands the power of modern technology, scientific decision-making, high cognitive ability, and high functioning organizations, has significant influence in the government of one of the great nations of the world.

Please consider applying for one of these positions. Dom is a special leader -- open to new ideas and to maverick personalities, loyal to his team, and a genuinely humble and good person.

This could be a once in a lifetime opportunity to make a positive impact in the world.

High skill immigration is one of the priorities for the new UK government. You do not need to be a UK citizen or permanent resident to be considered for these positions.
...we’re hiring data scientists, project managers, policy experts, assorted weirdos...

There are many brilliant people in the civil service and politics. Over the past five months the No10 political team has been lucky to work with some fantastic officials. But there are also some profound problems at the core of how the British state makes decisions. This was seen by pundit-world as a very eccentric view in 2014. It is no longer seen as eccentric. ...

Now there is a confluence of: a) Brexit requires many large changes in policy and in the structure of decision-making, b) some people in government are prepared to take risks to change things a lot, and c) a new government with a significant majority and little need to worry about short-term unpopularity while trying to make rapid progress with long-term problems.

There is a huge amount of low hanging fruit — trillion dollar bills lying on the street — in the intersection of:
the selection, education and training of people for high performance,

the frontiers of the science of prediction data science,

AI and cognitive technologies (e.g Seeing Rooms, `authoring tools designed for arguing from evidence’, Tetlock/IARPA prediction tournaments that could easily be extended to consider ‘clusters’ of issues around themes like Brexit to improve policy and project management)

communication (e.g. Cialdini)

decision-making institutions at the apex of government.
We want to hire an unusual set of people with different skills and backgrounds to work in Downing Street with the best officials, some as spads and perhaps some as officials. If you are already an official and you read this blog and think you fit one of these categories, get in touch.

The categories are roughly:

Data scientists and software developers
Economists
Policy experts
Project managers
Communication experts
Junior researchers one of whom will also be my personal assistant
Weirdos and misfits with odd skills

[ Please click through and read the whole post on Dom's blog ]
See also Now it can be told: Dominic Cummings and the Conservative victory 2019.

Note Added: Some of the media takes on Dom's job ad are extremely uncharitable. They (and the people they quote) assume Dom is entirely naive about when mathematical and computational methods might be useful, and when they might not. I suggest these people study his other writing carefully. For example:
More important than technology is the mindset – the hard discipline of obeying Richard Feynman’s advice: ‘The most important thing is not to fool yourself and you are the easiest person to fool.’ They [quant types] were a hard floor on ‘fooling yourself’ and I empowered them to challenge everybody including me. They [quant types] saved me from many bad decisions even though they had zero experience in politics and they forced me to change how I made important decisions like what got what money. We either operated scientifically or knew we were not, which is itself very useful knowledge.
Does this sound like a person who does not understand both the strengths and limitations of data science, statistics, careful epistemology, etc. in modern politics? Underestimate him at your peril...


Thursday, January 02, 2020

Andrew Hartman: The Culture Wars Then and Now (Manifold Podcast #27)



Note: We've moved to a weekly release schedule (previously one per two weeks).

Steve and Corey talk to Andrew about his new introduction to his book The War for the Soul of America. While the left largely won the culture wars, the three wonder whether the pendulum has swung so far left that many liberals are alienated by today’s cultural norms.

Other topics: Was the left’s victory in the debate over the college curriculum pyrrhic? Is identity politics a necessary step in liberation or a problematic slide toward greater division, or both? Are current students too sensitive, and easily triggered, to take the fight to the Billionaire class?

Transcript

Andrew Hartman (Faculty Profile)

A War for the Soul of America: A History of the Culture Wars


man·i·fold /ˈmanəˌfōld/ many and various.

In mathematics, a manifold is a topological space that locally resembles Euclidean space near each point.

Steve Hsu and Corey Washington have been friends for almost 30 years, and between them hold PhDs in Neuroscience, Philosophy, and Theoretical Physics. Join them for wide ranging and unfiltered conversations with leading writers, scientists, technologists, academics, entrepreneurs, investors, and more.

Steve Hsu is VP for Research and Professor of Theoretical Physics at Michigan State University. He is also a researcher in computational genomics and founder of several Silicon Valley startups, ranging from information security to biotech. Educated at Caltech and Berkeley, he was a Harvard Junior Fellow and held faculty positions at Yale and the University of Oregon before joining MSU.

Corey Washington is Director of Analytics in the Office of Research and Innovation at Michigan State University. He was educated at Amherst College and MIT before receiving a PhD in Philosophy from Stanford and a PhD in a Neuroscience from Columbia. He held faculty positions at the University Washington and the University of Maryland. Prior to MSU, Corey worked as a biotech consultant and is founder of a medical diagnostics startup.

Disclaimer: The views and opinions expressed on this program are those of the guest(s) and do not necessarily reflect the opinions or policies of the hosts, the Office of the Senior Vice President for Research and Innovation, or Michigan State University.

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