13. A system for using Resource Description Framework (RDF) reification to associate Semantic Web statements with start properties and stop properties related to lifetimes of the Semantic Web statements, comprising: a computer processor operable to access an RDF statement from a Semantic Web resource, wherein the RDF statement includes a subject, a predicate, and an object, determine a lifetime of the subject of the RDF statement, wherein determining the lifetime of the subject is based on at least one of a start property of the subject and a stop property of the subject, determine a lifetime of the predicate of the RDF statement, wherein determining the lifetime of the predicate is based on at least one of a start property of the predicate and a stop property of the predicate, determine a lifetime of the object of the RDF statement, wherein determining the lifetime of the object is based on at least one of a start property of the object and a stop property of the object, and determine a lifetime of the RDF statement based on an overlap of the lifetime of the subject, the lifetime of the predicate, and the lifetime of the object; and a reification processor operable to generate a reified RDF statement, wherein the reified RDF statement includes the subject, the predicate, the object and the lifetime of the RDF statement; and store the reified RDF statement in the Semantic Web resource.
14. The system of claim 13 , wherein the computer processor is further operable to: receive a Semantic Web query having an associated timeframe; determine if the query timeframe is within the lifetime of a reified RDF statement in the Semantic Web resource; and access the reified RDF statement in response to the determination.