The law of conservation of mass states that mass can neither be created nor destroyed. Interestingly, numerous ancient philosophers observed the knack for chemical and physical reactions to simply ...

The U.S. sees hundreds of mass shootings each year — so many that some people have survived more than one. A therapist offers advice for how to cope with the trauma.

Mothers and fathers of young men accused in shootings, including the 21-year-old charged in the massacre in Highland Park, Ill., have faced scrutiny.