Another Inconvenient Truth: The World's Growing Population Poses a Malthusian Dilemma

By 2050, the world will host nine billion people --and that's if population growth slows in much of the developing world. Today, at least one billion people are chronically malnourished or starving. Simply to maintain that sad state of affairs would require the clearing (read: deforestation) of 900 million additional hectares of land, according to Pedro Sanchez, director of the Tropical Agriculture and Rural Environment Program at The Earth Institute at Columbia University. [More]


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Readers Respond on "Knowing Your Chances"--And More...

Unintentional Comedy I have been really enjoying your magazine since I started reading it last year.

Ig Nobel Prizes Awarded

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When there are Nobel prizes there are Ig Nobel prizes, which were handed out at Harvard on October 1st. The awards honor research that “makes people laugh and then makes them think.” [More]


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Recommended: The Age of Empathy

The Sibley Guide to Trees by David Allen Sibley. Knopf, 2009 [More]


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Earthquakes Exert Global Influence

[ The following is an exact transcript of this podcast. ]

A powerful earthquake beneath the Pacific triggers a tsunami that devastates Samoa and American Samoa. Another powerful temblor strikes off the coast of Sumatra. But is there a connection beyond the fact that both sit on the geologically active Ring of Fire that encircles the Pacific Ocean?  

Long-Awaited Research on a 4.4-Million-Year-Old Hominid Sheds New Light on Last Common Ancestor

The first full analysis of a 4.4-million-year-old early human paints a clearer picture of what the last common ancestor of humans and chimpanzees may have looked like, which is not, after all, that much like a chimp at all. The ancient Ardipithecus ramidus ("Ardi", as the most complete female specimen is known) is described in 11 research papers published online today in Science . The prodigious research effort combines Ardi's fossils with those from many other Ar. ramidus individuals--both male and female--found near the Awash River in the Afar Rift region of Ethiopia. [More]


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You Snooze, You Lose -- Weight

Lose weight while you sleep? It sounds too good to be true--but recent research indicates that there is a connection between how much you weigh and the amount of shut-eye you get per night.

Two hormones, ghrelin and leptin, help to control appetite. When you do not get enough rest, levels of ghrelin, which increases hunger, rise; levels of leptin, which promotes feelings of fullness, sink. A study in the May issue of Psychoneuroendocrinology found a significant disruption in nighttime ghrelin levels in chronic insomniacs. According to the study, this hormone imbalance leads insomniacs to experience an increase in appetite during the day, leading to weight gain over time.

Gaming Tech Aids Scientists Building Virtual Synthetic Chromatophore

The study of processes that make life possible is hardly a leisurely pursuit, but that doesn't preclude researchers from taking advantage of the most advanced video gaming technology available to aid in their work. A team of University of Illinois at Urbana–Champaign (U.I.U.C.) physicists has assembled a supercomputer consisting of several hundred superfast graphics processing units (GPUs) --typically used for rendering highly sophisticated video game graphics--that they think will help them build a simulation depicting how chromatophore proteins turn light energy into chemical energy, a process called photosynthesis.

"Ninety-five percent of the energy that life on Earth requires are fueled by photosynthetic processes," says Klaus Schulten , a (U.I.U.C.) physics professor leading the simulation-building effort and director of the school's Theoretical and Computational Biophysics Group . To better understand how these processes work, Schulten's team is assembling a computer-based, virtual photosynthetic chromatophore . [More]


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The Dollars and Sense of Closing Schools for H1N1

Much has been made of the potential difficulties businesses face if numerous employees are out sick with the H1N1 "swine" flu . But there has been little information on the economic and other impacts if schools and day care centers continue to close temporarily to mitigate outbreaks. [More]


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Farmed Out: How Will Climate Change Impact World Food Supplies?

The people of East Africa once again face a devastating drought this year: Crops wither and fail from Kenya to Ethiopia, livestock drop dead and famine spreads. Although, historically, such droughts are not uncommon in this region, their frequency seems to have increased in recent years, raising prices for staple foods, such as maize. [More]


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The Effect of Our Surroundings on Body Weight

Obesity is a “global epidemic,” according to the World Health Organization. Two thirds of American adults and one third of school-age children are either overweight or obese (defined as extremely overweight). These proportions have been rising steeply, report the latest surveys. From 1960 to 2002 the population of overweight and obese adults increased by roughly 50 percent, and the corresponding increase for children was 300 percent. Compounding the problem, obesity rates in other countries are rapidly approaching those in the U.S.

What is causing this pandemic, and what can we do about it? Researchers have provided some tentative answers that fly in the face of commonly held beliefs. They suggest that the increase in obesity may be a result of environmental changes that tempt us into unhealthy habits and tend to overwhelm our psychological defenses against consuming too much and succumbing to fattening fare. In fact, environmental cues can exacerbate any innate tendency to use food as a balm for jittery nerves or sadness. Thus, many health experts advocate legislation--for instance, a tax on junk food--that promotes healthy eating. Others are trying to help individuals change their immediate eating milieu in ways that discourage overeating.

Carmakers and Utilities Charge Ahead on Making Electric Cars "Smart"

It will take years before there are enough electric cars and gas–electric hybrids on the road to put much of a dent in the output of the electrical grid . But once they do roll out en masse, these vehicles (and their drivers) will have to be smart about when they recharge so that utilities can avoid spikes in grid demand and drivers can avoid spikes in their electric bills. This puts carmakers and utility companies on the spot to develop a uniform technology that lets cars communicate with the grid, and vice versa. [More]


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Internet Addiction?

[Below is the original script. But a few changes may have been made during the recording of this audio podcast.] [More]


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Champagne Bubbles Liberate Flavor Compounds

Bubbles percolating up through a freshly poured glass of champagne do more than just tickle the tongue, according to a new study.  

A team of European researchers, publishing in this week's Proceedings of the National Academy of Sciences , finds that the bubbles in sparkling wine drag compounds that activate smell receptors to the surface of the sparkling wine and then shoot them upward where a taster can easily encounter them. (Although "champagne" technically refers to sparkling wines from the Champagne region of France, all effervescent wines should be subject to the same mechanism.)  

Champagne Bubbles Key To Taste

[ The following is an exact transcript of this podcast. ]

Let’s raise a toast to champagne. And its ubiquitous bubbles. Because new research says the bubbles aren’t just tickling your tongue. They’re erupting with aromas vital to the taste of the beverage.

Clean Energy Contest; and Counting Crickets and Katydids

The transcript of this podcast wil be posted in two to three weeks.

Scientific American podcast correspondent Cynthia Graber talks about the MIT Clean Energy Prize Competition. [More]


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Teen Inventors Fight Tinnitus

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Ever get a ringing in your ears after a loud blast of music on your iPod? That’s one example of the usually temporary condition called tinnitus, the sensation of sound even when no sound is being produced. But a new invention--created by high school students--may help.

Privacy and the Quantum Internet (preview)

Privacy is hard to come by these days, particularly on the Internet, where every time you Google something your desires are recorded for posterity--or at any rate, for advertisers.

Internet search companies say they protect their clients’ privacy by encrypting personal information and by using numbers instead of names to give their users anonymity. The problem is that anonymization is not always effective. AOL user number 4417749 found this out the hard way in 2006 when AOL decided to publish online a list of 20 million Web searches, including hers and those of 657,000 other users. Reporters were able to track down the 62-year-old widow in Lilburn, Ga., by analyzing the content of her searches. Luckily, Thelma Arnold was relatively unembarrassed by the revelation of her identity and intimate interests. How many of us could say the same?

Uncharted waters: Blown fuses and other troubles send the New Clermont back to the docks as the team regroups

Editor's Note: A team of Rensselaer Polytechnic Institute students was traveling up New York's Hudson River this week on the New Clermont , a 6.7-meter boat outfitted with a pair of 2.2-kilowatt hydrogen fuel cells to power the boat's motors. Their journey began September 21 from Manhattan's Pier 84 and was to cover 240 kilometers (at a projected speed of 8 kilometers per hour). After making several stops along the way, the crew originally expected to arrive back at Rensselaer Polytech's campus in Troy, N.Y., on September 25. This is the fourth of Scientific American.com's blogs chronicling this expedition, called the New Clermont Project . [More]


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MIND Reviews: Neuro-Economic Boom

Does sex really persuade us to buy a product? Why do economies slip into depressions? And how much do we let our emotions influence our decision making? A spate of new books tries to answer these and other questions about how we make our choices, why they are sometimes so far off the mark and what their consequences are.

Animal Spirits--How Human Psychology Drives the Economy, and Why It Matters for Global Capitalism (Princeton University Press, 2009) examines the relation between economic fluctuations and psychological forces. Economists George Akerlof and Robert Shiller explore how “animal spirits”--the term coined by economist John Maynard Keynes to describe levels of consumer confidence--lie at the core of such questions as why there is unemployment and why minorities are often particularly poor.