Advanced Invention

Turns out that a body reveals more details about its death than once thought

Whether it’s the blue, ragged fingernails of a heroin-overdose victim or the scaly skin of someone poisoned by arsenic, a corpse bears signs that unveil the secrets behind its life and death. Right now, 40,000 John and Jane Does wait in morgues. Although accident and murder victims are 15 to 30 times as likely to be autopsied as those who die of natural causes, even run-of-the-mill autopsies can yield important information on how a person died. This data has important implications for public health and safety and the legislation that governs those areas of interest. Autopsy findings have led to tougher military gear, fire-resistant clothing, crashworthy fuel systems and child-safe toys. They have also helped reveal how HIV, tuberculosis and West Nile virus are transmitted. Medical examiners are always looking for smarter, faster and more reliable ways to uncover the truth.

Here are five technologies that epitomize the old morgue maxim Mortui vivos docent: The dead teach the living.

Who knew that providing energy and water for all could be a matter of foot cranks and dirt power?

A garden hose, a tin can, duct tape, metal piping, kitchen cleaner, and gasoline: That is all television icon MacGyver needed to make a flame-thrower to ward off a swarm of killer ants. In the real world, technologies that are affordable and practical are not so simple to create, but they can make a huge impact on people’s lives. Instead of calling on complex solutions (reliant on engines and imported resources) for low-tech problems (such as cooking and lighting), some researchers are now developing what they call "confluent" technologies—ones that are effective, affordable, and sustainable for use in the developing world. Here’s a look at the latest breakthroughs:

1  Energy in a Bucket of Dirt
Who needs nickel cadmium batteries or coal plants for electricity when you have soil? A Harvard team of faculty and African students have tapped into soil-dwelling microbes in order to provide electricity for families in Tanzania. When the microbes found in the soil digest organic materials, they naturally produce a small current, which can be harnessed with a simple device consisting of two electrodes and a small circuit board. One trash-barrel-sized unit filled with soil can produce enough electricity to light two bedrooms for a decade or more, says Harvard biology professor Peter Girguis. While each unit currently costs about $50, the team is testing new materials that would drive the price down to $7.

2  Micro-Hydroelectric Power
Hilly land streaked with small streams makes an ideal spot for micro-hydroelectric power generators, each of which requires a meager water flow of just three gallons per second to turn. (To put this in perspective, the Mississippi’s average flow at New Orleans is about 4.4 million gallons per second.) The Appropriate Infrastructure Development Group (AIDG) has helped to build three systems in Guatemala, and more communities are now saving up money for local installations.

Scientists at Penn State have developed a new computational method that they say will help them to understand how life began on Earth. The team’s method has the potential to trace the evolutionary histories of proteins all the way back to either cells or viruses, thus settling the debate once and for all over which of these life forms came first.

The baobab tree represents one of the most ancient species of life on the planet. Scientists have investigated ancient and highly divergent proteins, called retroelements, whose evolutionary histories hold keys to uncovering the origins of life. (Credit: Randen Patterson and Damian van Rossum, Penn State)

"We have just begun to tap the potential power of this method," said Randen Patterson, a Penn State assistant professor of biology and one of the project’s leaders. "We believe, if it is possible at all, that it is within our grasp to determine whether viruses evolved from cells or vice-versa."

Two chemicals create a glowing (and poisonous) mixture that’s a window into the weird world of quantum physics

True Color: The release of photons that results from the combination of hydrogen peroxide and chlorine causes a vivid orange-red glow.

Before the discovery in the 1920s of quantum mechanics—laws that explain the way the world works on the very small scale of atoms and electrons—the fact that bleach and peroxide glow when mixed would have seemed like just another chemical reaction that gives off light, like fire or fireflies. But it’s actually a glimpse into the impossible.

Striking similarities between the brains of gay men and straight women have been discovered by neuroscientists, offering fresh evidence that sexual orientation is hardwired into our neural circuitry.

Scans reveal homosexual men and heterosexual women have symmetrical brains, with the right and left hemispheres almost exactly the same size. Conversely, lesbians and straight men have asymmetrical brains, with the right hemisphere significantly larger than the left.

Scientists at the prestigious Stockholm Brain Institute in Sweden also found certain brain circuits linked to emotional responses were the same in gay men and straight women.

The findings, published tomorrow in the US journal Proceedings of the National Academy of Sciences, suggest the biological factors that influence sexual orientation - such as exposure to testosterone in the womb - may also shape the brain’s anatomy.