The Motion of Light in Water: Sex and Science Fiction Writing in the East Village, is the autobiography of the science fiction author Samuel R. Delany in which he recounts his experiences growing up as a gay African American man, as well as some of his time in an interracial and open marriage with Marilyn Hacker.

It describes encounters with Albert Einstein, Bob Dylan, Stokely Carmichael and Stormé DeLarverie, a dinner with W. H. Auden, and a phone call to James Baldwin.

[2] The introduction puts an emphasis on the idea of the unreliable narrator; Delany's accounts often contrast his life as it "felt" to ways in which it actually occurred.

Hazel Carby called it one of two contemporary autobiographies that are "absolutely central to any consideration of black manhood" (the other being that of Miles Davis).

[5] Masha Gessen in O, The Oprah Magazine selected this title as a pick for the "Best LGBTQ Books of All Time", describing it as "a textbook in observing the self, thinking about sex and love, and the best writing manual I know".