Spaceland is a science fiction novel by American mathematician and computer scientist Rudy Rucker, and published in 2002 by Tor Books.

In a tribute to Edwin Abbott's Flatland, a classic mathematical fantasy about a 2-dimensional being (A. Square) who receives a surprise visit from a higher-dimensional sphere, Rudy Rucker's Spaceland describes the life of Joe Cube, an average, modern-day Silicon Valley hotshot who one day discovers the fourth dimension from an unexpected visitation.

Joe Cube is a high tech executive waiting for his company's IPO. On the New Year's Eve before the new millennium, trying to impress his wife Jena, he brings home a prototype of his company's new product (a TV screen that turns standard television broadcasting into a 3D image). It brings no warmth to their cooling marriage, but it does attract the attention of somebody else. Joe is suddenly contacted by a Momo, a woman from the fourth dimension she calls the All, of which our entire world (which she calls Spaceland) is like nothing but the thin surface of a rug.

Momo has a business proposition for Joe that she won't let him refuse. She is bent on making him start a company that will create a specific product that she will supply. The upside potential becomes much clearer for Joe once Momo "augments" him, by helping him grow a new eye on a 4D stalk, giving him the power to see in four-dimensional directions, as well as the ability to see into our dimension using a four-dimension perspective.

Strange Horizons felt that Joe's adventures were "thought-provoking", and compared the book positively to Ian Stewart's Flatterland, but faulted it for lacking in mathematical rigor.^[1] The A.V. Club considered it "fun yet thoughtful" and "unusually sedate", but criticized Rucker for his characterization.^[2] Publishers Weekly called it "a hilarious tribute (to Flatland);^[3] Kirkus Reviews, however, found it to be "not funny, not fascinating" and "for fans only",^[4] and the Notices of the American Mathematical Society—while conceding that it "is a fun read"—emphasized its shortcomings, including that Rucker is too repetitive and didactic, and that the characters are "one-dimensional (pardon the pun)".^[5]