KentuckyFC writes "If the universe is teeming with advanced civilizations capable of communicating over interstellar distances, then surely we ought to have seen them by now. That's the gist of a paradoxical line of reasoning put forward by the physicist Enrico Fermi in 1950. The so-called Fermi Paradox has haunted SETI researchers ever since. Not least because if the number of intelligent civilizations capable of communication in our galaxy is greater than 1, then we should eventually hear from them. Now one astrophysicist says this thinking fails to take into account the limit to how far a signal from ET can travel before it becomes too faint to hear. Factor that in and everything changes. Assuming the average communicating civilization has a lifetime of 1,000 years, ten times longer than Earth has been broadcasting, and has a signal horizon of 1,000 light-years, you need a minimum of over 300 communicating civilizations in the Milky Way to ensure that you'll see one of them. Any less than that and the chances are that they'll live out their days entirely ignorant of each other's existence. Paradox solved, right?"

f1vlad writes "Google is expected to announce the addition of ocean floor imagery to its Google Earth project, which will complete digital representation of our planet. 'The existing site, to which an estimated 400 million people have had access, already includes three-dimensional representations of large cities around the world and includes images from street-level and aerial photography covering thousands of miles across Britain and elsewhere. The new additions to the website are expected to include views of the ocean, and portions of the seabed. They will also provide detailed environmental data that will enhance information about the effect of climate change on the world's seas and oceans.'"

goran72 writes with news out of Malaysia that archaeologists have announced the discovery of stone tools more than 1.8 million years old — the earliest evidence of human ancestors in South-east Asia. Researchers believe the tools were made by members of the early human ancestor species Homo erectus. The tools actually date as slightly older than the earliest H. erectus fossils, which came from Georgia and China. No bones of that antiquity have so far been found in Malaysia. "The stone hand-axes were discovered last year in the historical site of Lenggong in northern Perak state, embedded in a type of rock formed by meteorites which was sent to a Japanese lab to be dated."

jamie points out a story in the Telegraph about a project to clone the Pyrenean Ibex (known also as bucardo), a species that went extinct in 2000. Before the last known member of the species died, scientists took tissue samples to begin a project to clone the animal. "Using techniques similar to those used to clone Dolly the sheep, known as nuclear transfer, the researchers were able to transplant DNA from the tissue into eggs taken from domestic goats to create 439 embryos, of which 57 were implanted into surrogate females. " Now, for the first time, one of them has survived the gestation period, living for seven minutes after birth. One of the researchers said, "The delivered kid was genetically identical to the bucardo. In species such as bucardo, cloning is the only possibility to avoid its complete disappearance."

Adam Korbitz writes "A former colleague of Edward Teller — father of the hydrogen bomb — has published a new paper proposing a design for what could be the first practical fusion-powered spacecraft (PDF). As described at Centauri Dreams, the design has certain similarities to MagOrion, a 1990s-era proposal for a nuclear-powered spaceship with a magnetic sail and propelled by small-yield fission devices. The proposal's author also has links to the British Interplanetary Society's Project Daedalus, a 1970s proposal for an unmanned fusion-powered interstellar probe designed to reach 12% of the speed of light on its way to Barnard's Star."

Rob Carr writes "According to the Cassini team, 'Recent images of Titan from NASA's Cassini spacecraft affirm the presence of lakes of liquid hydrocarbons by capturing changes in the lakes brought on by rainfall.' The northern lakes are now larger following a period in which hydrocarbon clouds covered their skies. (The research was published in the journal Geophysical Research Letters.) This change adds to the evidence these areas are indeed hydrocarbon lakes. But this discovery raises several more questions: where is the methane in the atmosphere coming from, and how long can this complex hydrocarbon cycle on Titan go on? The new evidence emphasizes the need for another mission to Titan."

sergio80 writes in with a timely piece of history in this the International Year of Astronomy, celebrating the 400th anniversary of the invention of the telescope. "Galileo Galilei is often credited with being the first person to look through a telescope and make drawings of the celestial objects he observed. While the Italian indeed was a pioneer in this realm, he was not the first..." That honor belongs to Thomas Harriot, an Englishman, who bought his first "Dutch trunke" (i.e. telescope) shortly after its invention in the Netherlands and made a sketch of the moon as seen through it in July of 1609.

mattrandy123 writes with news that scientists from NYU and Utrecht University have discovered ordinary plant cells can fulfill some of the same regenerative functions previously attributed to stem cells. Quoting: "In the study, the researchers cut off the plant's root tip, thereby excising the stem cell niche, and examined the return of cell identities by measuring all gene activity. The results suggested that stem cells returned quite late in regeneration after other cells were already replaced. The researchers then used mutant plants in which the stem cell niche no longer functions to confirm their initial observations. Despite the absence of the stem cell niche, the plant's ordinary cells worked to regenerate all the major tissues constituting the root tip — a process that began hours after it had been removed. However, researchers found that plants without functional stem cell niches could not resume normal growth, showing that other cells did not replace all functions of stem cells."

Urchin writes to tell us that physicists working in a new field called "phononics" claim that waste heat from a processor could actually be used to add to its power. "Crunching data coded using photons — photonic computing — is one example, and in 2007 researchers built the first workable optical transistor. But now the idea of computing using heat flow is gaining popularity among applied physicists. Heat travels through solid materials by means of phonons — ripples of vibration passing through a series of atoms. Those ripples can be used to send and store data in digital form: one temperature is read as 0 or 'off' while a second, higher temperature is interpreted as 1 or 'on.' Provided that the thermal memory is well insulated, it can keep its temperature — and data — intact for a long time."