What is pie in the sky?

"Pie in the sky" is an idiomatic expression used to describe an idea or plan that is very unlikely to happen or is overly optimistic and impractical. The phrase suggests something that is appealing and desirable but unattainable or unrealistic.

The origin of the expression dates back to the early 20th century and is often attributed to the American labor activist and songwriter Joe Hill. He used it in his 1911 song "The Preacher and the Slave," which was a parody of the hymn "In the Sweet By-and-By." In the song, Hill criticized religious leaders for promising rewards in the afterlife instead of addressing the immediate hardships faced by the working class. The phrase "pie in the sky" was used to convey the idea of being offered an illusory reward instead of tangible help.

Over time, the expression has been used in various contexts to describe unrealistic proposals or dreams that are unlikely to be realized.