February 21, 1998 | Volume 153 | Number 8
Cover: Light traveling through a finite, three-dimensional
universe would follow paths that repeatedly return to their starting points. An observer
inside such a universe would see multiple images of any objects present -- in this case,
two stars and a spaceship. (Illustration: © Geometry Center, University of Minnesota in
Available for Selected Articles
News of the Week:
Added Noise Keeps Waves Going
Fluctuations in light intensity can enhance the propagation of chemical waves, suggesting noise as a mechanism for long-range signaling in brain tissue.
Icy signs of warming emerge in Arctic
Satellite studies of sea ice provide evidence of Arctic warming.
Radar illuminates ancient Cambodian site
Radar maps and archaeological field work provide new insights into an ancient civilization at Angkor.
Male sex hormone, preeclampsia link found
Elevated testosterone in women who once had preeclampsia, a complication of pregnancy, hints that the condition signals heart disease risk later in life.
Rare regeneration fixes pierced mouse ears
A lab glitch may yield a newand raremammal model suitable for studying tissue regeneration.
Gamma-ray bursts: Farther and brighter?
The mysterious flashes of cosmic light known as gamma-ray bursts may be 20 times more energetic than previously estimated, and some may originate from the first galaxies born in the universe.
Gene cloned for stretchiest spider silk
The extreme elasticity of so-called capture silk comes from long spirals in the protein's configuration.
Electromagnetic fields may trigger enzymes
Magnetic fields can set off a cascade of enzyme-driven cell-signaling events, which could lead to cancer.
Worms hot ends set thermal record
Worms living near hydrothermal vents keep cool heads whereas their rumps are immersed in water too hot for any other multicellular organism to endure.
Land hermit crabs spurn leftovers
Hermit crabs avoid eating food that smells like their last meal.
Stroke drug reveals a dark side
Studies in mice raise questions about the effectiveness of a clot-dissolving substance used to treat stroke.
Cancer treatment and memory loss
High doses of toxic chemotherapeutic drugs in tandem with tamoxifen may increase the risk of cognitive deficits in women being treated for breast cancer.
Calculating a record prime
A college sophomore participating in the Great Internet Mersenne Prime Search has discovered the largest known prime number.
Overcoming quantum error
Accurate quantum computation is possible provided that the error per operation is below a threshold value.
Forests as pollution filters
Forests are more likely to pull pollutant gases rather than particles out of the air.
Bug sprays seem to really like toys
Pesticide foggers may leave residues that contaminate surfaces, especially plastic toys, for at least 1 week.
All Fired Up
Perception may dance to the beat of collective neuronal rhythms
Synchronized activity in selected groups of brain cells apparently underlies perception and other cognitive functions.
Circles in the Sky
Detecting the shape of the universe
Evidence of a finite, multiply connected universe may show up in microwave data from future spacecraft.
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