Sparks Fly

The amazing chemical reaction when sperm finally reaches an egg.

Researchers at Northwestern knew fertilization triggered millions of zinc particles, but they’d never actually seen the process until now.

Update, Dec. 19, 2014: This post has been updated to specify that the researchers who captured the footage are from Northwestern University.

Update, Nov. 28, 2016: This video has been removed pending the resolution of a licensing claim.