Who is Carl Sagan

Scientific American 

Piercing the Plasma: Ideas to Beat the Communications Blackout of Reentry

The frustrating communications blackout that can occur when a spacecraft reenters the atmosphere caused some tense moments in the earlier years of the space age--perhaps most memorably during the crippled Apollo 13 mission. But the phenomenon could also affect communications with new aircraft and weapons systems being contemplated now by the U.S. Air Force, which hopes to find ways to pierce the blackout. The problem arises when a speeding vehicle heats the air in front of it, ionizing it into plasma that blocks radio transmissions. It resembles the shock waves created when an airplane hits Mach 1 and breaks the sound barrier. In the case of reentering spacecraft and hypersonic aircraft, the plasma-shock boundaries form at speeds of about Mach 10. The space shuttle avoids the blackout because the craft's broad underside leaves an open area in the plasma plume trailing behind, enabling communications and telemetry data to be relayed to Earth through a network of satellites. But smaller craft are completely engulfed by the plasma. [More]

Call Me Melville, Based On New Word Use

Thieves may leave fingerprints at the scene of a crime. But does an author leave a metaphorical fingerprint on the book? The answer may be yes, according to a study published in the New Journal of Physics . Swedish physicists investigated how frequently authors use new words in their writing. This, they say, offers clearly identifiable patterns. The research goes against a belief held for more than 75 years that there's a sort of universality to how frequently authors use new words. [More]

Large Hadron Collider eclipses record for high-energy collisions

So far, 2009 has been a much kinder year to the Large Hadron Collider (LHC) than 2008 was. The gargantuan particle accelerator, sidelined for more than a year after a breakdown halted its initial run shortly after start-up in September 2008, has been steadily clearing performance benchmarks since resuming operations on November 20 of this year. In the weeks since the LHC's long-awaited reboot, the collider's operators have been putting the machine through its paces, circulating proton beams in both directions through the collider's 27-kilometer underground ring outside Geneva and later accelerating beams to world-record energies . [More]

Broader Interpretation Sought for Endangered Species Act

Nearly 130 scientists today asked the Interior Department to change a policy set under the Bush administration guiding how agencies decide whether a species is endangered. At issue is guidance issued in 2007 that redefined when the Fish and Wildlife Service would protect a species as "endangered" or "threatened." The Endangered Species Act requires protection of any species in danger of extinction throughout all or a significant portion of its range. [More]

New journal aims to reframe doctor-patient collaborations in health care

Swallow the doctor's diagnosis whole, or spend weeks plowing through the primary research literature at a medical library--at the risk of alienating your physician. Those were two of the primary choices available to lay people diagnosed 20 years ago with a serious disease. Today, motivated patients can use the Internet to dive well beyond WebMD , by joining online support groups and research-mining communities that often know more detail about etiology and treatment nuances than just about any medical specialist. [More]

Financier Soros sees $100 billion for climate talks

By Gerard Wynn and David Fogarty COPENHAGEN (Reuters) - Billionaire financier George Soros outlined a way to unlock $100 billion to help slow global warming on Thursday as talks on a new U.N. climate deal slowed over tough demands by the Pacific island state of Tuvalu. [More]

Senators outline compromise U.S. climate bill

By Timothy Gardner and Ayesha Rascoe WASHINGTON (Reuters) - Three U.S. senators outlined a compromise climate bill Thursday that aims to win the votes needed for passage next year and could boost President Barack Obama's position at U.N. climate talks in Copenhagen next week. [More]

Italy science council funds creationist book

After hosting a panel earlier this year to discuss supposed flaws in evolutionary theory , Italy's science agency the National Research Council (CNR) reportedly put up thousands of dollars to help with the publication of a follow-up book, Evolutionism: The decline of an hypothesis . The move has vexed many scientists in the country where the Vatican recently came out in support of Darwin's ideas . [More]

Newly Discovered T. Rex Relative Fleshes Out Early Dino Evolution

The earliest stages of dinosaur evolution remain buried under eons of rock, but the discovery of a new primitive carnivore fossil in the U.S. Southwest promises to dispel some of the debate about how these beasts spread across the globe--and about the origins of the group that eventually led to modern birds . [More]

Asia populated in one migratory swoop

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