Astronomers have spotted a near-perfect circle of light whose eerie shape was produced by a galaxy acting like an enormous lens. This "Einstein ring" is the first to be seen in infrared light, a team will report Wednesday in the Monthly Notices of the Royal Astronomical Society.
DALLAS--Radioactive tracers can reveal whether a breast tumor is shrinking in response to the drug tamoxifen, according to results from a pilot trial announced here yesterday at a national meeting of the American Chemical Society.
If evolution started all over again, would it repeat itself? In today's issue of Science, a real-life version of this thought experiment suggests that the answer may be yes--at least for island lizards.