Scientists achieve optical control of phase and group velocities in everyday liquids
The phase and the group velocity of light propagating in conventional optical media cannot exceed the speed of light in ...
wusf12h
This week in science: The fluid dynamics of crowds, a bird fossil and morning mindsets
NPR's Ailsa Chang talks with Emily Kwong and Regina Barber of Short Wave about the fluid dynamics of crowds, an early fossil of a modern bird and new data on how people's moods change through the day.