Could starships use cold fusion propulsion?

One small problem...

There's just one problem. We can achieve hot nuclear fusion, but recreating the intense temperatures and pressures that exist inside stars currently requires more energy than it gives back, so it's economically unfeasible, and pretty much an energy sinkhole for the time being.

If only we could achieve fusion at room temperatures! That's the claim of proponents of so-called "cold fusion," a field that has languished on the fringe since its alleged discovery almost 20 years ago. Back in 2000, TIME magazine listed cold fusion as one of the "worst ideas" of the 20th century.

Prevailing scientific opinion is still that the vast majority of cold fusion research falls under the rubric of "pathological science": the results are always on the verge of a stunning validation. Whenever said validation fails (again) to materialize, there is always a handy rationale for why it isn't really a definitive failure -- and why the naysayers are just closed-minded tools of the scientific establishment, conspiring to keep these unsung geniuses down.