What is the rainbow in Thomas Pynchon's Gravity's Rainbow (1973)?

The rainbow in Thomas Pynchon’s Gravity’s Rainbow is the arc a rocket makes from launch to target.

The novel is set in World War II Europe at the time German V-2 rockets were falling on London.

What is Newton's law of gravity? Actually called Newton's law of gravitation, it describes the degree…
What colors make up a rainbow? The colors red, orange, yellow, green, blue, indigo, violet make…
What are the seven deadly sins by Saint Thomas Aquinas? As set forth by scholastic theologian Saint Thomas Aquinas (c.…
How much was the option on Thomas Dixon, Jr.'s The Klansman, the book on which The Birth of a Nation (1915) was based? D. W. Griffith paid $2,500 for the rights to Thomas…
Who played Danny Thomas's Uncle Tonoose on "Make Room for Daddy" (ABC, CBS, 1953-64)? Hans Conried played Danny Thomas's Uncle Tonoose on the TV…
What was Danny Thomas's real name? Danny Thomas's real name was Amos Muzyad Jacobs (or Jahoob).

What is the rainbow in Thomas Pynchon’s Gravity’s Rainbow (1973)?