Sir

Your News story “Bubble-based fusion bursts onto the scene” (Nature 432, 940–941; 2004) states that bubble-fusion work “remains in limbo” after research conducted at Oak Ridge National Laboratory (ORNL) yielded inconclusive results in 2002.

However, a second paper was published by researchers at Purdue/ORNL in March last year and provided additional evidence for bubble fusion (R. P. Taleyarkhan et al. Phys. Rev. E 69, 036109; 2004). This paper underwent a second thorough review by a different group of ORNL scientists who supported its publication.

In my view, the 2004 paper provides evidence that shifts the question from “Can we drive fusion this way?” to “Can we produce net fusion energy this way?”.

A great deal of work will have to be performed before that more difficult question can be answered.