Category: Science

Relative to seat belts, maybe not.  Read Levitt and Dubner on this question.

Laurie David, comedy developer turned environmental activist, writes in the Huffington Post:

Last week at the G8, President Bush restated his favorite global
warming canard: that mandatory curbs on fossil fuel pollution will “cripple the U.S. economy.”

WELL, WHAT DOES HE THINK GLOBAL WARMING WILL DO TO THE ECONOMY!?!?
 
I wish there was an even bolder bold on this computer to emphasize how
insane this logic is. Non-stop flooding, killer heat waves, energy and
food shortages: what will these do to the economy?

Actually Laurie, and PGL of Angry Bear who links to David, the best study of the issue indicates that global warming is most likely a net benefit to the US economy.  Carbon dioxide and greater temperature makes plants grow faster.  The author, Yale economist Robert Mendelsohn writes:

Climate change is likely to result in small net benefits for the United States over the next century. The primary sector that will benefit is agriculture. The large gains in this sector will more than compensate for damages expected in the coastal, energy, and water sectors, unless warming is unexpectedly severe. Forestry is also expected to enjoy small gains. Added together, the United States will likely enjoy small benefits of between $14 and $23 billion a year and will only suffer damages in the neighborhood of
$13 billion if warming reaches 5C over the next century. Recent predictions of warming by 2100 suggest temperature increases of between 1.5 and 4C, suggesting that impacts are likely to be beneficial in the US.

Speaking personally, I have undergone a greater shift in mean temperature by moving from Canada to the US than will occur in 100 years of global warming and I like it!  My fellow Canadians, still stuck in the frozen north, will be glad to know that in the future they too can have warmer temperatures without giving up their prized health care system.

For the developing world the effects of climate change are most likely negative but not so negative that further development – combined with some modest changes in first-world technology, such as greater use of nuclear power – is not the best solution.

Reading this made me sad:

Early detection [of a bomb] can backfire because of the grisly fact that human beings act as human shields.  "There is a trade-off between crowd size and crowd blocking," says Prof. Kaplan.  A large, dense crowd puts more people in harm’s way, but "the probability of being exposed to a bomb fragment declines exponentially with the size of the crowd."  As a crowd flees, there are fewer people near the bomber to absorb the fragments (as when a soldier falls on a grenade) and more people, unshielded, farther away.  Simple geometry shows that you can hit more people at a radius 20 feet from a bomber than you can five feet from him…The same effect occurs if people throw themselves to the ground  That minimizes each person’s exposed area, but also at the expense of decreasing human shielding.  For bombs with 500 or more fragments (in Israel, 1,000 is typical), "hit the deck" can raise rather than cut casualties.

That is from The Wall Street Journal, 8 July 2005, by Sharon Begley.

First, there has been no such ban.  While some aid agencies and NGOs have discouraged DDT spraying, the reality is less brutal than polemics sometimes suggest.  Tim Lambert has an overview of the evidence.  Here is a good follow-up post called Eritrea cuts malaria rates by switching away from DDT.

The best place to sell magazines could be in the gym locker room, according to a study which found that pheromones in male sweat makes men opt for a manly read.

Men under the influence of androstenol – a pheromone found in men’s underarm sweat – find men’s lifestyle magazines to be more attractive and are more likely to purchase them than those not exposed to the pheromone, suggests the research.

Here is the full story.

You yakkers will drown out ET:

Using cellphones on aeroplanes could drown out faint radio signals from space, astronomers are warning. They told a US agency considering lifting in-flight restrictions on cellphones that special devices should be installed on planes to limit damage to research if the regulations change…

Cellphone use on planes "could be a disaster for us", says Michael Davis, director of projects at California’s SETI Institute, which searches for signs of extraterrestrial intelligence, and former chair of the NAS committee. "We have incredibly sensitive radio telescopes – even a single cellphone on a single plane 100 miles away could cause pretty serious damage", he told New Scientist. It would exceed recommended "noise" levels by 10 times.

That is partly because cellphone signals from planes are not blocked by trees or buildings as they are on the ground, allowing them to travel straight into astronomers’ telescopes. "Putting cellphones in a plane is like building a cellphone tower 40,000 feet high," says Davis.

Here is the full story.  And we all know that ET, rather than tricking us into producing malevolent self-replicating spawn, will instead tell us how to solve the Riemann Hypothesis, right?

A woman’s genetic make-up accounts for at least a third of her ability to climax during sex, say researchers, and may even account for as much as 60%.

Here is one good summary.  Here is further discussion.

This is a rechargable electrified tennis-racket for swatting flies
and mosquitos: "Just press on the switch and a live electric current flows
through the inner mesh and the moment a mosquito, bug or fly comes touches it,
it gets a electric shock and gets zapped.

My only question.  Does it work on children?

Thanks to Cory Doctorow at Boing Boing Blog.

Smoking cessation programmes that use text messaging can double the
quit rate in young smokers, according to a clinical trial in New
Zealand.

The
trial led by Anthony Rodgers, director of the Clinical Trials Research
Unit at the University of Auckland, NZ, is the first to test the use of
mobile phones as an aid to giving up smoking.

In
the study, over 850 young smokers who wanted to quit received text
messages, such as: “Write down 4 people who will get a kick outta u
kicking butt. Your mum, dad, m8s?”

The
smokers, whose average age was 25 years old, received five messages a
day for a week before their designated “quit day”, and for the
following four weeks. Then they received three messages a week for a
further five months. They were also given one month of free personal
texting, starting on their quit day, as an incentive.

A
similar group of young smokers received one month free texting six
months after their designated quit day, but no text messages designed
to help them quit.

Six
weeks after quit day, 28% of the group that received the texts claimed
to have quit, compared with 13% of the control group. To check these
self-reported results, the team analysed levels of cotinine, a nicotine
breakdown product, in the saliva of one in 10 of the participants. The
results were the same for both groups – about half of those who claimed
to have given up were actually still smoking. Quit rates appeared to
remain high after six months, although the results are less certain
because many of the participants were lost to follow up.   

   

Repetition does matter; here is the story.

At lunch the other day Robin Hanson offered a perceptive comment on marriage and divorce (I paraphrase).

We tend to remember slights and frustrations more than favors and kindnesses.  So inevitably in a marriage the weight of negative remembrances of thing past comes to exceed that of the positive.  Divorce is the result.

The secret to a good marriage, therefore is selective forgetfulness.  Coincidentally some psychologists have recently come to the same conclusion.  The couples who stay together are the delusional ones – the ones who look at their past with rose-colored glasses.

Psychologists believe that what they are observing in couples who endorse these and similar sentiments are strongly selective memories that ignore inevitable negative events over the course of marital history. Maybe a distorted view of your marriage that emphasises the positive and forgets the negative is crucial to accounting for who stays and who flees when it comes to relationship endurance.

Similarly:

A kindred spirit is someone who appears especially to understand us and uniquely share our experiences, probably because they see the world they way we do and are therefore, in important respects, just like us.

Murray’s group measured marital partners’ personalities, values and day to day feelings and compared these to marital satisfaction. Those in the happiest and most stable marriages were those most likely to believe their partners were most like them – that is, "kindred spirits" – even when objective comparison of personality found that the similarity was much more imagined than real.

Meanwhile Bryan over at EconLog offers some useful ideas on how to remember and how to forget.

…corvids and psittacines [have cognitive powers superior to most apes].  That’s really the culmination of studies beginning in the
1970’s (most famously Irene Pepperberg’s studies on grey parrots and Herrnstein’s on pigeons) and is something that has only just become, I think, mainstream biological thought around now: but it rests on as firm experimental obsrvation as any studies of primates (certainly of orangutans).  Corvids and psittacines simply outperform even chimpanzees in many ways.  …On the other hand, the selective pressures on birds are pretty nasty. Their biochemistry seems a hell of a lot better than ours (witness the longevity of these things).  So perhaps it’s an alternate route to great intelligence: if you know that say four out of five young are going to die anyway you can take the risk of 80% of the offspring being quickly developed morons.  I don’t know enough about the field to validate that but I think it’s an interesting idea.

Christof Koch, in his The Quest for Consciousness, claims that dual strategy beings can outcompete zombies.  Yes parts of the brain are designed for rapid, single purpose use, as you might find in a zombie.  But other more integrative and judgmental parts require more powerful central processing units, namely your conscious mind.  In his view consciousness is not just an epiphenomenal feeling, as in much analytical philosophy, but rather it is a functional set of qualia.  In other words, consciousness helps you interpret "meaning" and thus use information about the natural world more effectively.  Consciousness allows you to summarize the present state of the world in abbreviated fashion and to make plans on that basis.  Consciousness is a sometimes-slow but always flexible strategy. 

Here is one good summary of the argument; read this excerpt:

Consider the following situation: You see an outstretched hand, but instead of shaking it immediately, which instinct would dictate, you are required to close your eyes and wait several seconds before doing so. Koch and Crick suspect that without a short-term memory, a zombie could not do this task, or any other in which an artificial delay was imposed between “an input and the associated motor output.” Absence, like presence, has a neurological signature, and Koch imagines a kind of “conscious-ometer” that could be used to measure who and what is consciously aware.

Note also that efficient zombie-like behavior often requires conscious learning in the first place.  Isaac Stern might best play the violin by "letting go," but he first needed many hours of conscious practice to reach this state.  So consciousness and zombie behavior are often complements rather than substitutes.

If you are interested in these issues, this book is the place to start.  Try also this skeptical response.

I was skeptical when my wife handed me a small plastic toy saying, "think of something, after twenty questions it will guess."   But twenty questions later it answered correctly.  Weird and a little freaky.

20Q is featured today in Kevin Kelly’s Cool Tools.  He provides some interesting brackground information:

Burned into its 8-bit chip is a neural net that has been learning for 17
years. Inventor Robin Burgener programmed a simple neural net on a DOS machine
1988. He taught it 20 questions about a cat. He than passed the program around
to friends on a floppy and had them challenge the neural net with their yes/no
answers to the object they had in mind. The neural net learns only when it plays
a game; no data is added except for the yes/no answers of visitors. So the more
people who test it, the more they teach it. In 1995 Burgener put the now robust
neural net onto the new web where anyone could play it (that is, train it) 24
hours a day. And they did. Burgener’s genius was to turn the hard tedious work
of training a neural net into a fun game for humans.

Last year, after 1 million rounds of 20 questions online, the neural net had
accumulated 10 million synaptic associations. It has a 73% success rate of
guessing what you thought. Burgener then compressed the 20Q code to run on a
chip, and had the neural net select 2,000 of the most popular 10,000 objects it
then knew about. He then had the neural net select out the most useful 250,000
synaptic connections related to those 2,000 objects, and hard wired that
learning into the chip in the orb….

The toy is remarkable. Because it is so small, so autonomous, its
intelligence is shocking to the unprepared. Most children can’t stump it, and if
you stick to objects it will stump smart adults about 80% of the time with 20
questions and most of the time with an additional 5 questions. I love to watch
people’s reactions when they think of a "hard" thing, and after a seemingly
irrational set of questions you are convinced are dumb, the sly ball tells you
what you had in mind….

right now, for ten bucks, you can get an amazing little artificial
intelligence, about as smart as an insect — but an insect which specializes in
guessing what object you are thinking of. And in that part of the brain, it’s
smarter than you are.

Thanks also to Boing Boing Blog for the link.