They used light-sensitive molecules to turn on and off nerve cells in the deep brain structure of mice.

VOA: special.2009.04.07

One shows the remains of a dying star four thousand light years away which has thrown off a cloud of glowing hydrogen gas.

VOA: special.2009.09.30

He could turn off a light and then jump into his bed before the room got dark.

VOA: special.2009.01.24

If dark matter particles exist, scientists say, they should be able to observe a small amount of light given off when they hit the nucleus of a xenon atom.

VOA: special.2009.07.21