Category: Science

I have yet to read this study but I found the summary intriguing:

Bad moods can actually be good for you, with an Australian study finding that being sad makes people less gullible, improves their ability to judge others and also boosts memory.

The study, authored by psychology professor Joseph Forgas at the University of New South Wales, showed that people in a negative mood were more critical of, and paid more attention to, their surroundings than happier people, who were more likely to believe anything they were told.

"Whereas positive mood seems to promote creativity, flexibility, cooperation, and reliance on mental shortcuts, negative moods trigger more attentive, careful thinking paying greater attention to the external world," Forgas wrote.

"Our research suggests that sadness … promotes information processing strategies best suited to dealing with more demanding situations."

Furthermore:

The study also found that sad people were better at stating their case through written arguments, which Forgas said showed that a "mildly negative mood may actually promote a more concrete, accommodative and ultimately more successful communication style."

I thank Claire Hill for the pointer.

So all you sad people can cheer up now.  Or not.

The author is Sean Carroll and the subtitle is The Quest for the Ultimate Theory of Time.  This book-to-appear offers a very good summary of the paradoxes of time.  The new contribution (new to me, at least) is to offer an integrated discussion of the multiverse, the law of entropy, de Sitter space, and the foundations of the so-called "arrow of time."

Carroll argues that the invocation of baby universes clears up a lot of apparent puzzles:

The prospect of baby universes makes all the difference in the world to the question of the arrow of time.  Remember the basic dilemma: The most natural universe to live in is de Sitter space, empty space with a positive vacuum energy…most observers will find themselves alone in the universe, having arisen as random arrangements of molecules out of the surrounding high-entropy gas of particles…

Baby universes change this picture in a crucial way.  Now it's no longer true that the only thing that can happen is a thermal fluctuation away from equilibrium and then back again.  A baby universe is a kind of fluctuation, but it's one that never comes back — it grows and cools off, but it doesn't rejoin the original spacetime.

What we've done is given the universe a way that it can increase its entropy without limit.

…[pages later]  In this scenario, the multiverse on ultra-large scales is symmetric about the middle moment, statistically, at least, the far future and the far past are indistinguishable…[yet] The moment of "lowest" entropy is not actually a moment of "low" entropy.  That middle moment was not finely tuned to some special very-low-entropy initial condition, as in typical bouncing models.  It was as high as we could get, for a single connected universe in the presence of a positive vacuum energy.  That's the trick: allowing entropy to continue to rise in both directions of time, even though it started out large to begin with.  There isn't any state we could possibly have chosen that would have prevented this kind of evolution from happening.  An arrow of time is inevitable.

Is it all true?  Beats me.  But if you read this book you will come away more hopeful about the prospects of a relatively simple "theory of everything."

Here is the author's home page; he teaches at Cal Tech.  Here is his personal page.  Best of all, here are his talks.  His Twitter feed is here.

Here is a link to the chapter which is causing all the controversy.  Out here in Edmonton I haven't been following the blog debates, although at every meal I am asked about carbon taxes and tar sands.  (By the way, I believe the Alberta strategy is to pay any forthcoming tax and be profitable enough to keep on producing fossil fuel energy.)  My view is to be skeptical of geo-engineering as a solution, for reasons outlined here.  In any case it's a question I'll be thinking more about.  Among the questions I need to think through more are how bad is it to control global temperature but keep the CO2 in the air, how much acidification of the oceans matters, how geo-engineering affects the variance of global climate, and what the long run looks like if the world becomes "addicted" to the eighteen-mile hose or whatever is used.  For a start on the current brouhaha, here is a link to Krugman and Levitt.  Mark Thoma offers up other links.

Addendum: This post seems to imply the chapter reproduction is not authorized, so I've taken down the link to the link.

They titled the piece "Older but not Wiser."  Here is the summary result:

Michael Callaham, editor-in-chief of the Annals of Emergency Medicine in San Francisco, California, analysed the scores that editors at the journal had given more than 1,400 reviewers between 1994 and 2008. The journal routinely has its editors rate reviews on a scale of one to five, with one being unsatisfactory and five being exceptional. Ratings are based on whether the review contains constructive, professional comments on study design, writing and interpretation of results, providing useful context for the editor in deciding whether to accept the paper.

The average score stayed at roughly 3.6 throughout the entire period. The most surprising result, however, was how individual reviewers' scores changed over time: 93% of them went down, which was balanced by fresh young reviewers coming on board and keeping the average score up. The average decline was 0.04 points per year.

"I was hoping some would get better, and I could home in on them. But there weren't enough to study," says Callaham. Less than 1% improved at any significant rate, and even then it would take 25 years for the improvement to become valuable to the journal, he says.

I thank Michelle Dawson for the pointer; I wonder when the editor who ran the study, Callaham, thinks he should resign.  He's totally gray.

It's now a rather famous anecdote in the life and times of Michael
Jordan that he was cut from the varsity when he was in high school. You
think that's merely a footnote more than 30 years later? You think
Jordan's forgotten the details or is willing to let go? Guess whom
Jordan invited to the Hall of Fame Friday night? Leroy Smith, the kid
who took his spot on the high school team. Jordan said he's still
saying "to the coach who picked Leroy over me: 'You made a mistake,
dude.' "

That is from Michael Wilbon, here is more.

Addendum: Here is another version of the tale.

Which conspiracy theory is most likely to be true?

John Thacker points us to a study of California (registration required, but free).  I've only browsed it but the introduction states:

In September 2008, the California state legislature passed the first state law (Senate Bill 375) to include land use policies directed at curbing urban sprawl and reducing automobile travel as part of the state’s ambitious strategy to reduce greenhouse gas (GHG) emissions. The legislature recognized that cleaner fuels and more fuel-efficient vehicles would not be sufficient to achieve the state’s goal of reducing GHG emissions to 1990 levels by 2020. The bill requires the state’s 18 metropolitan planning organizations to include the GHG emissions targets established by the state Air Resources Board (ARB) in regional transportation plans, and to offer incentives for local governments and developers to create more compact developments and provide transit and other opportunities for alternatives to automobile travel to help meet these targets. ARB currently estimates that reductions in vehicle miles traveled (VMT) resulting from these actions will contribute only about 3 percent of the 2020 targets–an estimate that reflects uncertainties in the state of knowledge about the impacts of more compact development patterns on travel and the short time horizon involved.

In other words, the environmental benefits of checking pro-suburb subsidies are real, but they are smaller than many people think.  That's from the National Academy of Sciences and the authors are no haters of the environment.  If you check out p.59, you'll see that a forty percent increase in population density decreases vehicle miles traveled by less than five percent.  pp.131-132 offer a summary of the study's conclusions and quantitative estimates. 

The authors conclude that density-friendly policies are a good idea, and I agree, but still these are not overwhelming effects.  Keep in mind that current trends are strongly pointing toward population dispersion, so to reverse those trends and see greater density would take some doing.  We're not close to that margin.

There are many other interesting parts of the report, including case studies of Portland and Arlington.