In the past several years, the nation’s two most populous states have passed new statutes specifically intended to address the issue of rapidly changing scientific and technological knowledge, perhaps signaling a national trend. This reflection article situates a discussion of these “changed science statutes” within a sociological understanding of the nature of scientific knowledge, exploring the question of what it means for scientific knowledge to “change.” It then traces the procedural history of the two cases widely credited with prompting the passage of the statutes and courts’ varying interpretations of the statutes. It suggests that, while changed science statutes offer broad potential for redressing the use of impugned science in closed cases, courts have thus far limited their applicability through narrow interpretation of the statutes.