Recommended: The Age of Empathy

The Sibley Guide to Trees by David Allen Sibley. Knopf, 2009 [More]


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Readers Respond on "Obama's Science"

Tax Dollars at Work Despite Barack Obama appointing scientists to top posts, I hardly think this qualifies him personally to be named in the “ Scientific American 10 .” His inclusion pales beside the favor bestowed to the others on the list who have actually done some real work for science and humanity. [More]


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How Quantum Effects Could Create Black Stars, Not Holes (preview)

Black holes have been a part of popular culture for decades now, most recently playing a central role in the plot of this year’s Star Trek movie. No wonder. These dark remnants of collapsed stars seem almost designed to play on some of our primal fears: a black hole harbors unfathomable mystery behind the curtain that is its “event horizon,” admits of no escape for anyone or anything that falls within, and irretrievably destroys all it ingests.

To theoretical physicists, black holes are a class of solutions of the Einstein field equations, which are at the heart of his theory of general relativity. The theory describes how all matter and energy distort spacetime as if it were made of elastic and how the resulting curvature of spacetime controls the motion of the matter and energy, producing the force we know as gravity. These equations unambiguously predict that there can be regions of spacetime from which no signal can reach distant observers. These regions--black holes--consist of a location where matter densities approach infinity (a “singularity”) surrounded by an empty zone of extreme gravitation from which nothing, not even light, can escape. A conceptual boundary, the event horizon, separates the zone of intense gravitation from the rest of spacetime. In the simplest case, the event horizon is a sphere--just six kilometers in diameter for a black hole of the sun’s mass.

Privacy and the Quantum Internet (preview)

Privacy is hard to come by these days, particularly on the Internet, where every time you Google something your desires are recorded for posterity--or at any rate, for advertisers.

Internet search companies say they protect their clients’ privacy by encrypting personal information and by using numbers instead of names to give their users anonymity. The problem is that anonymization is not always effective. AOL user number 4417749 found this out the hard way in 2006 when AOL decided to publish online a list of 20 million Web searches, including hers and those of 657,000 other users. Reporters were able to track down the 62-year-old widow in Lilburn, Ga., by analyzing the content of her searches. Luckily, Thelma Arnold was relatively unembarrassed by the revelation of her identity and intimate interests. How many of us could say the same?

50 Years Ago: Kidney Transplantation

OCTOBER 1959 FOUNDER OF KIDNEY TRANSPLANTS -- “Identical-twin grafts have demonstrated that where an immunological barrier does not exist kidneys can be successfully transplanted to cure otherwise incurable kid­-ney and vascular disease. We transplanted a kidney from a healthy man to his criti­cally uremic brother. Though the men were probably not identical twins, we hoped that their relationship might make for some immunologic compatibility. The recipient was given a total dose of X-rays large enough to depress his reticuloendothelial tissues severely. As the patient’s reticuloendothelial system recovers from the radiation, it may be forced to become familiarized with the antigens and the transplanted kidney. It is as yet too early to evaluate the results of this transplant, but initially it appears to be successful. -- John P. Merrill ”

New Cooling Technology Uses Air "Bullets" to Shoot Down Overheated LEDs

Light-emitting diodes (LEDs) really shine as an energy-efficient, long-lasting source of illumination in sensors, flashlights and video screens. For larger and more powerful LEDs to succeed in replacing incandescent and fluorescent bulbs in home and industrial lighting, however, they must be designed to better keep their cool. [More]


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Why Are We Annoyed by the Sound of Nails on a Chalkboard?

Physiologically, why is the sound of fingernails on a blackboard so unnerving? Is this effect particular to human beings, or are other creatures similarly affected? --Rowan Snyder, via e-mail

Positions of Genes Inside the Cell Nucleus Exert Biological Effects

For decades the cell nucleus has been a black box of biology--scientists have understood little about its structure or the way it operates. But thanks in part to new visualization technologies, biologists have recently begun probing the architecture of the nucleus in real time. And they are discovering that this architecture appears to change as we age or fall ill or as our needs shift. In fact, the structure of nuclear components--chromosomes, RNA, protein complexes and other small bodies--could be as biologically important as the components themselves.

It is not surprising that the nucleus is carefully organized. The human genome’s 3.2 billion DNA base pairs have to be compacted 400,000-fold to fit within the tiny space--yet genes must also interact with one another there and with the machinery that transcribes them into proteins. Nuclear structure has historically been difficult to study because scientists had to rely on electron microscopy or antibody stains, which show cellular components only at single points in time. In the 1990s, however, biologists started using green fluorescent protein to observe nuclear components in living cells in real time, much like a movie. “A picture is worth 1,000 words, and I always like to say a movie is worth one million words,” says David L. Spector, a cell biologist at Cold Spring Harbor Laboratory.

Recovered meteorite points to an unusual origin

Meteorites can reveal a lot about the composition and formation of their parent bodies, but such postcards from beyond come with no return address, making their provenance difficult to establish. Often, astronomers must observe the object's inbound trajectory and then trace its orbit backward through time to nail down the region of space or the specific parent body that a meteorite sprang from. ( In one unprecedented case announced in March , a group of researchers had the added advantage of having spotted the object in space before its atmospheric entry.) [More]


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A New Vision for Teaching Science (preview)

We face a real crisis in science education in America. Representative Bart Gordon of Tennessee, chair of the House Committee on Science and Technology, has warned that countries such as China and India will trample the U.S. economy in the near future without major improvements in teaching. Indeed, our schools are falling behind. In the 2006 Program for International Student Assessment (PISA)--a respected measure of achievement around the globe--the average science score of U.S. 15-year-olds dropped below that of teens in 28 out of 57 participating countries. (In math, U.S. students fared even worse, lagging behind their peers in 34 nations.)

Despite decades of reform, America has made only modest gains in the science classroom, particularly in high schools. Two recent reports from the National Research Council (NRC), however, offer novel strategies. Entitled Taking Science to School and Ready, Set, Science! , they call for changes in the way science is taught beginning in elementary school. Unlike previous recommendations, the new suggestions reflect recent findings from neuroscience and psychology about how young children think and how they acquire knowledge.

A 360-Degree Virtual Reality Chamber Brings Researchers Face to Face with Their Data

Scientists often become immersed in their data, and sometimes even lost. The AlloSphere , a unique virtual reality environment at the University of California, Santa Barbara, makes this easier by turning large data sets into immersive experiences of sight and sound. Inside its three-story metal sphere researchers can interpret and interact with their data in new and intriguing ways, including watching electrons spin from inside an atom or "flying" through an MRI scan of a patient's brain as blood density levels play as music. [More]


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Jupiter borrowed a passing comet to make a moon for 12 years

The middle of the 20th century was an eventful time in terms of Earth's geopolitics. In the spring of 1949, the North Atlantic Treaty Organization (NATO) was taking shape , and simmering tensions in Korea hinted at the war that would begin there the following year. Twelve years later, in the summer of 1961, President John F. Kennedy was in his first year of office and had already committed the U.S. to reaching the moon before the decade was out . [More]


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Tree Electricity Runs Nano-Gadget

[ The following is an exact transcript of this podcast. ]

If scientists have their way, we may someday be tapping maples--not for pancake fixin’s, but for power. Because researchers from the University of Washington in Seattle have found there’s enough electricity flowing in trees to run an electronic circuit. [More]


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Electron Bolts: Even Deeply Bound Electrons Can Escape Molecules via Quantum Tunneling

In quantum mechanics particles can escape from their confines, even if a barrier stands in their way, via a process known as tunneling. Tunneling is no mere quantum curiosity--tunneling electrons, for instance, are harnessed by scanning tunneling microscopes to observe on the smallest scales . Those probes can image a surface at the atomic level by detecting the tunneling of electrons from the surface across a small gap to the microscope's tiny scanning tip. [More]


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Japanese Lunar Mission Provides a Glimpse at How the Moon Took Shape

The leading hypothesis for the moon's formation contends that a massive impact billions of years ago knocked a wealth of planetary material off of Earth, which coalesced into our lunar companion. [More]


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The U.S. Must Prioritize Its Carbon Strategy [Extended version]

The House of Representatives passed the American Climate and Energy Security Act in June and sent it to the Senate. The House bill, running to 1,428 pages, aspires in one breathtaking stroke to take on renewable energy, carbon capture and sequestration (CCS), nuclear power, electric vehicles, carbon cap-and-trade, power transmission, energy efficiency and climate adaptation. It ranges from grand vision to minuscule details such as technical specifications on lighting fixtures.

What’s missing in this sprawling draft is prioritization. The bill rightly recognizes that America and the rest of the world require a fundamental overhaul in energy technology and use. The insecurity of global oil supply lines, the growing global scarcity of conventional fossil fuels and the urgency to reduce carbon emissions all point to the need for a fundamental energy overhaul. Yet to accomplish such a worldwide, fundamental energy overhaul, we will need to keep our eye on the big picture--the technology systems that will make a large and lasting difference--and not get mired in excruciating details.   

Researchers Claim to Cook Up Isolated Magnetic Poles

Magnets are remarkable exemplars of fairness--each north pole is invariably accompanied by a counterbalancing south pole. Split a magnet in two, and the result is a pair of perfectly neutral magnets, each with its own north and south. [More]


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The Real Sea Monsters: On the Hunt for Rogue Waves

A near-vertical wall of water in what had been an otherwise placid sea shocked all on board the ocean liner Teutonic --including the crew--on that Sunday in February, more than a century ago. [More]


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Astronomical Survey Reveals Andromeda's Galaxy-Gorging Past

A highly detailed survey of the nearby Andromeda Galaxy, which as a nearby spiral galaxy is something of an observational proxy for our own Milky Way, shows the remnants of smaller galaxies that our neighbor appears to have cannibalized. [More]


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100 Years Ago: Punch Cards and the Census

SEPTEMBER 1959 RADIATION -- “What should the citizen conclude about ionizing radiation? Ionizing radiation has always been with us and will be for all foreseeable time. Our genetic system is probably well adjusted by natural selection to normal background radiation. Added radiation will increase the frequency of mutations; most of these will be harmful. Exposure to radiation in large amounts will increase malignant disease; small amounts may possibly do the same. In view of these potentially harmful effects every reasonable effort should be made to reduce the levels of ionizing radiation to which man is exposed to the lowest levels that can reasonably be attained. As to fallout from nuclear-weapons tests, the citizen will conclude that it contributes in a small way to world-wide levels of radiation. For this reason alone the tests should be discontinued. --George W. Beadle”