Robotic helicopters learn complex tricks by analyzing demos.
A company says 3-D nanoparticles boost the efficiency of water purification.
A lensless imaging system finds and recognizes the shadows of T cells and bacteria.
California's secretary of state says open-source software is needed to safeguard electronic voting systems.
The director of the U.S. Office of Health IT Adoption explains why it's so hard to get doctors to go digital.
BP's chief scientist, Steven Koonin, says cutting greenhouse emissions will take major changes.
Researchers have created healthy stem cells from adult cells--no embryo required.