Tag Archives: Science

A Galactic Garden

By Robin Hanson · November 1, 2009 10:20 pm · Comments (5)

In August I wrote:

A few years ago PCW Davies persuasively argued that Earth life more likely started on Mars.  Last year, Napier and coauthors argued that comets are an even more likely source:

A single comet of radius 10 km and 30% volume fraction of clay contains as much clay, to within a factor of around 10, as that of the early Earth. However, our Solar System is surrounded by about 1011 comets forming the Oort cloud …  Whereas the average persistence of shallow clay pools and hydrothermal vent concentrations of clay on the Earth can range from 1 to around 100 years, a cometary interior provides a stable, aqueous, organic-rich environment for around 106 years.

The larger the region from which life could plausibly have started and then come to Earth, the more likely Earth life becomes in that scenario, and the more believable is whatever theory suggested that scenario.  The latest Scientific American suggests to me an even larger plausible region of orgin: life’s origin may go back to the tight warm mixing cluster of stars where the Sun formed.  Simon Zwart: Continue reading "A Galactic Garden" »

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There Is No Science

By Robin Hanson · September 17, 2009 3:00 pm · Comments (23)

Eric Falkenstein:

I like listening to journalists talk about science … most of the translation to outsiders comes from non-scientists simply because there are more of them, and some write very well.  Yet, I find many times, when these journalists digress from a specific subject, to science in general they are extremely naive or duplicitous. If you go to The Skeptic’s Guide to the Universe, you invariably hear a bunch of caricatures of those who disagree with conventional wisdom on science—most of which truly are quacks, but not always—and they pedantically emphasize how these alternative views are ‘not science’: they have beliefs that do not have peer-reviewed tests supporting a falsifiable hypothesis. …

When journalists talk about science in general this is usually a pretext for saying those who disagree with their favorite idea are wrong, because they are unscientific. … They then caricature their opponents, taking the most inarticulate advocates from the other side, and skewering their illogic. They then sit back and take take inordinate pride in their scientific pretensions, as if their selective discussion was objective. The fact is, most ‘big’ scientific issues do not conform to the scientific method, where one puts out testable hypotheses, rejecting ones that are falsified.

He’s right: “science” basically means “study”, and there just is no simple way for outsiders to tell who is studying something well.  The best way to study a subject depends a lot on the details of that subject.  We have a few rough guides to expertise, such as careful language, formalism, attention to detail, years of study, IQ, cleanliness, endorsement by respected folks, etc., but there is no surefire ‘science’ checklist that can tell outsiders if research is good.

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Words Vs. Bets

By Robin Hanson · September 11, 2009 3:00 pm · Comments (36)

I once had a long discussion with Ken Steiglitz about P=NP, while I was still at Princeton. … Ken was and still is sure that P must not be equal to NP. Okay, I said to Ken, what are the odds that they are equal? Ken said that he thought the odds were a million to one. I immediately suggested a bet. I did not ask him to “bet his life,” but I did ask for a million to one bet. I would put up one dollar. If in say ten years P=NP had not been proved, then he would win my dollar. If P=NP was proved in that time frame, then I would win a million dollars from Ken. Ken said no way. After more discussion the best bet I could get out of Ken was {2} to {1}.  Two to one. That was the best he would do.

That is from Richard Lipton; hat tip to Michael Nielsen.  Does anyone doubt that two to one better summarizes his evidence than a million to one?

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Just Beautiful

By Robin Hanson · September 9, 2009 9:40 pm · Comments (8)

nebulaDon’t miss the hi-res version.

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Why Does Pharma Study Placebos?

By Robin Hanson · August 26, 2009 6:00 pm · Comments (35)

As head of Lilly’s early-stage psychiatric drug development in the late ’90s, Potter saw that … the company’s next-generation antidepressants were faring badly, too, doing no better than placebo in seven out of 10 trials. … Potter discovered, however, that geographic location alone could determine whether a drug bested placebo or crossed the futility boundary. By the late ’90s, for example, the classic antianxiety drug diazepam (also known as Valium) was still beating placebo in France and Belgium. But when the drug was tested in the US, it was likely to fail. Conversely, Prozac performed better in America than it did in western Europe and South Africa. It was an unsettling prospect: FDA approval could hinge on where the company chose to conduct a trial. …

AsPotter and his colleagues [also] discovered that ratings by trial observers varied significantly from one testing site to another. It was like finding out that the judges in a tight race each had a different idea about the placement of the finish line. … The placebo response is highly sensitive to cultural differences. Anthropologist Daniel Moerman found that Germans are high placebo reactors in trials of ulcer drugs but low in trials of drugs for hypertension—an undertreated condition in Germany, where many people pop pills for herzinsuffizienz, or low blood pressure. Moreover, a pill’s shape, size, branding, and price all influence its effects on the body. Soothing blue capsules make more effective tranquilizers than angry red ones, except among Italian men, for whom the color blue is associated with their national soccer team—Forza Azzurri! …

AsIn the spring, Potter, who is now a VP at Merck, helped rev up a massive data-gathering effort called the Placebo Response Drug Trials Survey.  Under the auspices of the NIH, Potter and his colleagues are acquiring decades of trial data—including blood and DNA samples—to determine which variables are responsible for the apparent rise in the placebo effect. Merck, Lilly, Pfizer, AstraZeneca, GlaxoSmithKline, Sanofi-Aventis, Johnson & Johnson, and other major firms are funding the study, and the process of scrubbing volunteers’ names and other personal information from the database is about to begin.  In typically secretive industry fashion, the existence of the project itself is being kept under wraps. NIH staffers are willing to talk about it only anonymously, concerned about offending the companies paying for it.

More here.  Gee, do you think drug companies will use their better understanding of placebo effects to help us all better distinguish effective from useless drugs, or do you think they will instead use it to game the FDA approval process, to make more of their drugs look better than placebos?  What do these two theories predict about how secretive they would be about such research?

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CO2 Warming Looks Real

By Robin Hanson · May 30, 2009 6:00 pm · Comments (69)

Many have bent my ear over the last few months about global warming skepticism.   So I’ve just done some moderate digging, and conclude:

  1. In the last half billion years, CO2 has at times been 15 times denser, but not more than 10C warmer.  So that is about as bad as warming could get.
  2. In the last million years, CO2 usually rises after warming; clearly warming often causes CO2 increases.
  3. CO2 is clearly way up (~30%) over 150 years, and rising fast, mainly due to human emissions.  CO2 is denser than its been for a half million years.
  4. The direct warming effect of CO2 on warming is mild and saturating; the effects of concern are indirect, e.g., water vapor and clouds, but the magnitude and sign of these indirect effects are far from clear.
  5. Climate model builders make indirect effect assumptions, but most observers are skeptical they’ve got them right.
  6. This uncertainty alone justifies substantial CO2 mitigation (emission cuts or geoengineering), if we are risk-averse enough and if mitigation risks are weaker.
  7. Standard warming records show a real and accelerating rise, roughly matching the CO2 rise.
  8. Such warming episodes seem common in recent history.
  9. The match between recent warming and CO2 rise details is surprisingly close, substantially raising confidence that CO2 is the main cause of recent warming.  (See this great analysis by Pablo Verdes.)  This adds support for mitigation.
  10. Among the few bets on global warming, the consensus is for more warming.
  11. Geoengineering looks far more likely to be feasible and acceptable mitigation than emissions cuts.
  12. Some doubt standard warming records, saying they are biased by urban measuring sites and arbitrary satellite record corrections.   Temperature proxies like tree rings diverge from standard records in the last fifty years. I don’t have time to dig into these disputes, so for now I defer to the usual authorities.

It was mostly skeptics bending my ear, and skeptical arguments are easier to find on the web.  But for now, the other side has convinced me.

Added: The Verdes papers is also here.  Here is his key figure: Continue reading "CO2 Warming Looks Real" »

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Reinventing Idea Futures

By Robin Hanson · May 27, 2009 6:00 am · Comments (34)

From the April Physics World:

A key problem, suggests mathematical physicist Eric Weinstein of the Natron Group, a hedge fund in New York, is that it is too easy for scientists in the “establishment” of any field to cut down new ideas, and to do so without really putting anything at risk, thereby leading to a culture that is systematically biased toward caution. …

Weinstein suggests another idea — that we should borrow some ideas from financial engineering and make scientists back up their criticisms by taking real financial risks. You think that some new theory is utterly worthless and deserving of ridicule? In the world Weinstein envisions, you could not trash the research in an anonymous review, but would buy some sort of option giving you a financial stake in its scientific future, an instrument that would pay off if, as you expect, the work slides noiselessly into obscurity. The money would come from the theory’s proponents, who would similarly benefit if it pans out into the next big thing.

Weinstein’s point is that markets, in theory at least, work efficiently and — putting the current financial meltdown to one side — lead to the accurate valuation of products. They exploit the “wisdom of crowds”, as a popular book of the same title recently put it. Take the famous electronic prediction markets at the University of Iowa, which pool the views of thousands of diverse individuals and consistently seem to give better predictions than any expert. …

“It would be more efficient,” he says, “if the maverick could demand of the critic, if my theory is so obviously wrong, why don’t you quantify that by writing me an options contract based on future citations in the top 20 leading journals secured by your home, furniture, holiday home and pension?”

This article makes it seem like Eric reinvented idea futures.  Except that Eric and I discussed the concept last May, when we had two phone conversations and exchanged seven emails.

In 1996, a Russ Ray published a paper in Futures Research Quarterly that was basically cut and paste from my Idea Futures paper.  Imitation is the sincerest form of flattery, right?  Hat tip to Jef Allbright.

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Cloud Seeding Works

By Robin Hanson · May 1, 2009 3:00 pm · Comments (13)

Folks have been seeding clouds to induce rain for over a century, but weather variability has made it hard to collect clear evidence that seeding increases rainfall.  Because of this, many consider cloud-seeding to be a psuedo-science.  But the latest Journal of Applied Meteorology and Climatology presents relatively strong support:

An analysis of cloud seeding activity for the period 1960–2005 over a hydroelectric catchment (target) area located in central Tasmania is presented. The analysis is performed using a double ratio on monthly area averaged rainfall for the months May–October. Results indicate that increases in monthly precipitation are observed within the target area relative to nearby controls during periods of cloud seeding activity. Ten independent tests were performed and all double ratios found are above unity with values that range from 5–14%. Nine out of ten confidence intervals are entirely above unity and overlap in the range of 6–11%. Nine tests obtain levels of significance greater than the 0.05 level. If the Bonferroni adjustment is made to account for multiple comparisons, six tests are found to be significant at the adjusted alpha level. Further field measurements of the cloud microphysics over this region are needed to provide a physical basis for these statistical results.

Absence of evidence is not evidence of absence; sometimes it can just take a long time for clear evidence to accumulate.

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The intervention and the checklist: two paradigms for improvement

By Andrew · February 19, 2009 2:45 pm · Comments (9)

I’m working on a project involving the evaluation of social service innovations, and the other day one of my colleagues remarked that in many cases, we really know what works, the issue is getting it done. This reminded me of a fascinating article by Atul Gawande on the use of checklists for medical treatments, which in turn made me think about two different paradigms for improving a system, whether it be health, education, services, or whatever.

The first paradigm–the one we’re taught in statistics classes–is of progress via “interventions” or “treatments.” The story is that people come up with ideas (perhaps from fundamental science, as we non-biologists imagine is happening in medical research, or maybe from exploratory analysis of existing data, or maybe just from somebody’s brilliant insight), and then these get studied (possibly through randomized clinical trials, but that’s not really my point here; my real focus is on the concept of the discrete “intervention”), and then some ideas are revealed to be successful and some are not (with allowances taken for multiple testing or hierarchical structure in the studies), and the successful ideas get dispersed and used widely. There’s then a secondary phase in which interventions can get tested and modified in the wild.

The second paradigm, alluded to by my colleague above, is that of the checklist. Here the story is that everyone knows what works, but for logistical or other reasons, not all these things always get done. Improvement occurs when people are required (or encouraged or bribed or whatever) to do the 10 or 12 things that, together, are known to improve effectiveness. This “checklist” paradigm seems much different than the “intervention” approach that is standard in statistics and econometrics.

The two paradigms are not mutually exclusive. For example, the items on a checklist might have had their effectiveness individually demonstrated via earlier clinical trials–in fact, maybe that’s what got them on the checklist in the first place. Conversely, the procedure of “following a checklist” can itself be seen as an intervention and be evaluated as such.

And there are other paradigms out there, such as the self-experimentation paradigm (in which the generation and testing of new ideas go together) and the “marketplace of ideas” paradigm (in which more efficient systems are believed to evolve and survive through competitive pressures).

I just think it’s interesting that the intervention paradigm, which is so central to our thinking in statistics and econometrics (not to mention NIH funding), is not the only way to think about process improvement. A point that is obvious to nonstatisticians, perhaps.

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Our Biggest Surprise

By Robin Hanson · February 6, 2009 11:30 am · Comments (75)

We as a civilization know a lot more today than a random hunter-gatherer from fifty thousand years ago knew.  At a fun dinner with Cosmic Variances's thoughtful Sean Carroll last night, I asked:  What have we learned that is the most surprising?  Sean initially answered "quantum mechanics" but I complained that bundles together too many different things we've learned; I instead want to know what single feature of have we learned would most surprise our distant ancestors? 

Sean then suggested non-determinism, that quantum mechanics appears to suggest that the past does not determine the future.  I suggested what would most surprise our distant ancestors is how big is our universe.  It is big in time and space, in extent and detail, and in the range of things that can fill this extended detailed spacetime. 

So what would you say has been our biggest surprise, weighing not just raw info but also that info's relevance? 

Added:  OK, I see two related surprises, one empirical and one logical. The empirical surprise is that the universe really is big.  The logical surprise is that a big enough universe with a small number of simple essenses can reproduce all of the complex local phenomena that one might otherwise explain via design or a large number of essences.  So per Eliezer and Julian, enough inanimate objects can produce animate object behavior, and per Jed enough incremental adjustments can produce bio and social order.

More added:  Sean remembers the conversation a bit differently; he's probably right. He also asks "the complementary question: what is the most surprising thing about the universe that we haven’t yet discovered, but plausibly could?"

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