'Warming link' to big hurricanes

Records for the past 35 years show that hurricanes have got stronger in recent times, according to a global study. This fits with mounting evidence which suggests the biggest storms around the world - hurricanes, typhoons and cyclones - are intensifying.

Some US scientists say that greenhouse warming may be driving the most severe events, such as Katrina, although more research is needed to be sure.Their assessment of hurricane activity is published in the journal Science.

Are Wormholes Tunnels for Time Travel?

As any self-respecting science fiction fan knows, wormholes theoretical shortcuts through space and time make for excellent time travel portals.

The latest movie to transport people into the past is this summer's A Sound of Thunder, based on the classic 1952 Ray Bradbury novella. In it, a group of hunters build a time machine, which looks like a wormhole of sorts, to travel back to the dinosaur era. There, things go awry when one hunter kills a butterfly, which completely changes the course of history.

The movie was widely panned by critics and seems to have quickly slipped out of theaters. But the questions it raises the mystery of time and the possibilities of traveling through it remain among the thorniest in physics, keeping a growing number of scientists occupied.

It's not like scientists are looking for a way to actually travel through time. But some believe that theorizing about how it could be done maybe by using a wormhole in space will help them understand and perhaps even revise the laws of physics.

"Traversable wormholes are extremely useful as gedanken experiments" the term describes experiments that can be reasoned theoretically but are impractical to carry out "to probe the limitations of general relativity," said Francisco Lobo, an astrophysicist at the University of Lisbon in Portugal.

Via National Geographic Video: Why Harvest Moon Looms Large (requires Windows Media Player and a high-speed connection!)

Earth Asteroid Bombardment Mystery Solved?
Scientists turned planetary detectives say they may have solved a solar system whodunit: What caused a cataclysmic asteroid assault on Earth and neighboring planets some 3.9 billion years ago?

Researchers suspect that the devastating bombardment, which lasted between 20 and 200 million years, originated in the main asteroid belt between Jupiter and Mars.

The U.S.-led team based their conclusion on evidence found in the unhealed wounds of ancient asteroid collisions left on the moon and the inner planets Mars, Mercury, and Venus.

Writing in tomorrow's issue of the journal Science, the scientists note that the intense period of crater-making impacts, known as the late heavy bombardment, was likely caused by repositioning of the solar system's giant outer planets.

'Better' DNA out of fossil bones
Improved technologies for extracting genetic material from fossils may help us find out more about our ancient ancestors.

Scientists in Israel have just developed a new technique to retrieve better quality, less contaminated DNA from very old remains, including human bones.

It could aid the study of the evolution and migration of early modern humans, as well as extinct populations such as our close relatives, the Neanderthals.