Even the Chinese government suspects the massive dam may cause significant environmental damage

China's Three Gorges Dam: An Environmental Catastrophe?

Why I hope the search for extraterrestrial life finds nothing.

Where Are They?

The sex of new babies is influenced by the mother's diet before she conceives, a new study suggests. According to a survey of 740 British mums to be, a high-calorie diet is more likely to lead to a baby boy in nine months' time.

An appetite for sex : Nature News

Some predicted that this book would be the death knell of the idea of group selection. No longer would evolutionary biologists suggest that natural selection worked to promote the good of the species (group selection) or even the individual and his close relatives who share many of his genes (kin selection, a type of group selection).

But prediction is difficult in a contingent world such as ours, where life is complex and accidents and coincidences wield so much power. Has "The Selfish Gene" in fact killed off group selection ideas? Why not? And what effect has the book had instead?

Reconsiderations: Richard Dawkins and His Selfish Meme

In novels and films, the most common scientist by far is the mad one. From H. G. Wells’s Dr. Mo­­reau to Ian Fleming’s Dr. No to Stanley Kubrick’s Dr. Strangelove, scientists are portrayed as evil geniuses unrestrained by ethics and usually bent on world domination. Over the past two years, as I struggled to write my own novel about physicists and their quest for the Theory of Everything, I often worried that I was falling prey to this stereotype myself. It is incredibly difficult to create fictional scientists who are neither insane villains nor cardboard heroes. To faithfully depict the life and work of a researcher, you need to immerse yourself in the details of his or her research, and very few writers have done this task well.

We Need More Novels about Real Scientists

A 32-page primer from the National Academies.

What You Need to Know About Energy

Networks -- used throughout the sciences in the study of biological, technological, and social complexity -- can often be too complex to visualize or understand.

In a May 1 Nature paper, “Hierarchical structure and the prediction of missing links in networks,” Santa Fe Institute (SFI) researchers Aaron Clauset, Cristopher Moore, and Mark Newman show that many real-world networks can be understood as a hierarchy of modules, where nodes cluster together to form modules, which themselves cluster into larger modules -- arrangements similar to the organization of sports players into teams, teams into conferences, and conferences into leagues, for example.

This hierarchical organization, the researchers show, can simultaneously explain a number of patterns previously discovered in networks, such as the surprising heterogeneity in the number of connections some nodes have, or the prevalence of triangles in a network diagram. Their discovery suggests that hierarchy may, in fact, be a fundamental organizational principle for complex networks.

Unlike much previous work in this area, Clauset, Moore, and Newman propose a direct but flexible model of hierarchical structure, which they apply to networks using the tools of statistical physics and machine learning.

Nature paper describes technique for extracting hierarchical structure of networks

Unlike adults, children don't integrate different types of sensory information.

One sense at a time

Far from protecting the environment, most rail transit lines use more energy per passenger mile, and many generate more greenhouse gases, than the average passenger automobile. Rail transit provides no guarantee that a city will save energy or meet greenhouse gas targets.

While most rail transit uses less energy than buses, rail transit does not operate in a vacuum: transit agencies supplement it with extensive feeder bus operations. Those feeder buses tend to have low ridership, so they have high energy costs and greenhouse gas emissions per passenger mile. The result is that, when new rail transit lines open, the transit systems as a whole can end up consuming more energy, per passenger mile, than they did before.

Even where rail transit operations save a little energy, the construction of rail transit lines consumes huge amounts of energy and emits large volumes of greenhouse gases. In most cases, many decades of energy savings would be needed to repay the energy cost of construction.

Rail transit attempts to improve the environment by changing people’s behavior so that they drive less. Such behavioral efforts have been far less successful than technical solutions to toxic air pollution and other environmental problems associated with automobiles.

Does Rail Transit Save Energy or Reduce Greenhouse Gas Emissions?

NPR:

Engineers build bridges, buildings, roads, structures that shelter us and help us move around. But now there's a new class of engineer. These folks build living things.

Minty E. Coli and Other Bioengineering Feats