This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, reproduction and adaptation in any medium and for any purpose provided that it is properly attributed. For attribution, the original author(s), title, publication source (PeerJ PrePrints) and either DOI or URL of the article must be cited.
It is proposed an information theoretic search engine is like RADAR. The query words are the emitted signals and the document database is the object to be detected. Various echoes come off the database, and analogous with echo cancelation, the signal with the lowest entropy is selected. Commensurate with Shannon's theory, low entropy documents are signal, higher entropy documents are noise. Thus, my proposal separates signal from noise. As many relevant documents can be tined to be signal as desired.