Introduction to the Main Experimental Findings of the LENR Field

Twenty-five years ago in March 1989, Martin Fleischmann and Stanley Pons announced their success in initiating fusion between deuterons in palladium used as the cathode in an electrolytic cell. Since then, a battle has waged between skeptics who reject the claim and people who observe behaviour that is consistent with the claim. This article briefly summarizes the major experimental observations. A companion article in this special section provides insight into how the observations might be explained.