Add Yahoo as a preferred source to see more of our stories on Google. A monarch butterfly (Dannaux plexippus) flaps its wings in Piedra Herrada Sanctuary, Mexico. Might this start a chain of events ...

If the truth is stranger than fiction, you gotta believe that the butterfly effect is real.

Is the 2004 Ashton Kutcher vehicle The Butterfly Effect a good movie? Definitely not, no—but try telling that to me at age thirteen. And then wrap your head, once more, around the fact that if you had ...

For the first time, engineers have created a model that flies just like a real butterfly. Powered only by an elastic band, it flits up and down and flaps its wings languidly – just like the ...