Octopuses have two alternating sleep states, study shows

Octopuses are known to sleep and to change color while they do it. Now, a study publishing March 25 in the journal iScience finds that these color changes are characteristic of two major alternating sleep states: an "active ...

The potential economic impact of volcano alerts

The Volcano Alert Level (VAL) system, standardized by the United States Geological Survey (USGS) in 2006, is meant to save lives and keep citizens living in the shadow of an active volcano informed of their current level ...