Scientific American Online

By Katharine Sanderson

It was an instrument that much of the astronomical community didn't want, but times change: to get time now on the Hubble Space Telescope, which is celebrating its 20th anniversary this week, an astronomer usually faces competition from at least 11 other eager scientists.

Hubble, named after American astronomer Edwin Hubble, has been orbiting Earth for 20 years, sending back images in the visible, near-infrared and ultraviolet parts of the spectrum. [More]

WASHINGTON (Reuters) - They may all look similar, but killer whales, also known as orcas, include several distinct species, according to genetic evidence published on Thursday.

The Center for Biological Diversity (CBD) has filed a massive petition to protect 404 freshwater species in the southeastern U.S. The list includes 48 fish, 92 mussels and snails, 92 crayfish and other crustaceans, 82 plants, 13 reptiles (including five map turtles), four mammals, 15 amphibians, 55 insects, and three birds. The species live in Alabama, Arkansas, Georgia, Florida, Kentucky, Louisiana, Mississippi, North Carolina, South Carolina, Tennessee, Virginia and West Virginia.

Why seek protection for so many species at once? The CBD says they all form a cohesive ecosystem, and they depend upon each other for their survival. According to the CBD's Web site about what it refers to as the southeastern freshwater extinction crisis , "All these species are intricately interconnected: For example, the map turtles' survival depends on the abundance of snails and mussels, which they eat, while mussels depend on fish to host their larvae--and the fish, in turn, depend on the abundance of flies, whose larvae they consume."

MONTREAL--A good night's sleep, or even just a nap, can be an aid to memory. Psychologists have known for years that sleep solidifies what we've learned during the day, transforming tenuous associations into stable ones. Learning while you snooze seems supremely efficient, and so people have long dreamed of co-opting this process so that their dozing brain shores up what matters to them--say, material they've studied for a test or a talk, or verbiage in a foreign language they want to master. But until now there has been little support for the notion that studying in your sleep is useful. Psychology graduate student John Rudoy at Northwestern University in Illinois reported findings here on Monday at the Cognitive Neuroscience Society 2010 annual meeting that hint at a way to do that. [More]

Is it possible to see something without knowing you can see it? Maybe that's not so hard to imagine if you think of subliminal images flashed for a frame or two on a movie screen--too quickly for you to see consciously but perhaps long enough to add a frisson of fear. (Those frames in The Exorcist don't count--if you can notice them, they're not subliminal.) [More]

I used to scoff at the idea of Minute Rice. I mean, are we really in such a rush that we can’t wait, like, 10 minutes for a regular old bowl of rice? Well, yes, yes we are. And fast food may be making matters worse. Because a study in the journal Psychological Science shows that even a glimpse of those golden arches makes us act impatiently. [More]

When we learn something, for it to become a memory, the event must be imprinted on our brain, a phenomenon known as consolidation. In turn, every time we retrieve a memory, it can be reconsolidated--that is, more infor­mation can be added to it. Now psychologist Liz Phelps of New York University and her team report using this “reconsolidation window” as a drug-free way to erase fearful memories in humans.

Although techniques for over­coming fearful memories have existed for some time, these methods do not erase the initial, fearful memory. Rather they leave participants with [More]

What is human uniqueness, and how did it contribute to what we could now call behavioral modernity? How did it develop? And what implications does it have for understanding our present and future? This past February the Origins Project that I direct at Arizona State University helped to convene an interesting meeting of paleontologists, anthropologists, primatologists, evolutionary biologists, geneticists, archaeologists and psychologists to attempt to address such questions, among others.

I began the meeting by pointing out that when some people heard about its subject, they had asked me what was so unique about humans? Surely all animals are unique in their own way, and although we have special traits, so do bees and giraffes. But as my A.S.U. colleague Kim Hill has put it, “Even before the invention of agriculture, human communities may have eventually numbered around 70 million individuals ... as Homo sapiens spread over the planet more broadly than any other large vertebrate. No creature on earth lives in cohesive social units that rival this complexity or biomass.”

By Patrick Lannin

REYKJAVIK (Reuters) - Iceland's volcanic eruption was still causing strong tremors on Thursday, though far less ash and smoke was pouring out into the air.

Writer and activist Bill McKibben talks to Scientific American 's Mark Fischetti about his new book Eaarth: Making A Life On A Tough New Planet . [More]

A new sun-studying satellite had its coming-out party Wednesday, when scientists involved in the project presented early imagery and videos from the spacecraft's instruments at a news conference at the Newseum in Washington, D.C. The Solar Dynamics Observatory, or SDO , launched by NASA in February, gathers a voluminous stream of data about the star nearest Earth, observations that should help heliophysicists better understand the workings of the sun and improve forecasts of solar activity that can cause problems on Earth. [More]

By Timothy Gardner

WASHINGTON (Reuters) - The U.S. military, the government's largest fuel buyer, is leading the fight against climate change by investing in the "Great Green Fleet" and other ways of cutting dependence on oil and coal, according to a Pew Charitable Trusts report released on Tuesday.

By Tim Cocks

ABIDJAN (Reuters) - Six years after the insect killer DDT was globally outlawed on grounds of environmental damage, two researchers say there are new reasons for doubting the chemical is harmful and are urging its use against malaria.

WASHINGTON--Many doctors and medical researchers applauded a new federal focus on comparative effectiveness research that was boosted through the 2009 stimulus package and codified with the signing of the health care reform bill in March. This shift will support--and in many cases require--work to establish which treatments work best. [More]

Air travel in Europe inched back to normal Wednesday, as officials estimated that newly opened flight routes would permit air traffic to approach 75 percent of its normal capacity. Ash plumes from Iceland's Eyjafjallajökull volcano had all but extinguished flight operations across the U.K. and mainland Europe for the better part of a week . [More]

Spring is coming earlier, and nature is scrambling to keep up, according to scientists who say climate change is to blame.

The season starts an average of 10 days earlier in the United States than it did just 20 years ago. And that is scrambling the delicate balance of many ecosystems, as some species adapt to the change and others don't.

Volcanoes, with their vast outpourings of greenhouse gases and sun-screening ash clouds, can affect climate. But what about the other way around? [More]