A food additive that has been used for decades is stirring up controversy. We talk with a Chicago researcher who is in the midst of clinical trials to uncover its potential hazards. Ash-har Quraishi has the story in tonight's Scientific Chicago.

View a slideshow of flood photos from Chicago Tonight viewers, producers and reporters. Submit your flood photos here and we will add them to the photo gallery.

How prepared are we to deal with a flood of today’s magnitude, or worse? We talk with area officials and a National Weather Service meteorologist to discuss today’s reaction and the future.

After days of rain, severe thunderstorms dumped nearly five inches of precipitation Wednesday and overnight into Thursday morning, flooding highways and roads across the city. We have the latest updates on closures and weather. Submit your flood photos here.

Could a better helmet hold the key to reducing the epidemic of sports-related brain injuries? Ash-har Quraishi talks with a team of university researchers who say it’s time for a new design. We revisit the story.

Pieces of a famed Russian meteorite land at the Field Museum. Eddie Arruza has the story.

In tonight's Scientific Chicago, Ash-har Quraishi takes a look at a recent scientific study that delves deep into what happens as we recall events from our past.