The Physicists I know have widely panned this entire branch of research as a waste of resources. I find it extremely difficult to accept that meaningful fusion on an scale useful as a energy source can be achieved with this approach, much less that fusion is even occurring at all.
The Wright brothers were widely panned by experts in the field of manned flight. You should withhold judgement for a few more years at least until this plays out.
The article includes doubts from Seth Putterman who has said Taleyarkin's early experiments were flawed and has doubts about this experiment but even he says he expects eventual results from bubble fusion.
"The Physicists I know have widely panned this entire branch of research as a waste of resources. I find it extremely difficult to accept that meaningful fusion on an scale useful as a energy source can be achieved with this approach, much less that fusion is even occurring at all."
Nuclear fission gives off a very similar signature (e.g. a 2.5MeV neutron even) to what has been recorded in these experiments...and nuclear fission occurs *naturally*...so it's hardly surprising that it is being observed in a lab experiment.
They claim that they are observing fusion, and they *may* be right (certainly that's the path to grant money), but I'm skeptical. They may just be observing fission.
As for scaling this sort of thing up, there are hurdles. Bubbles can only exist so close to each other. If the density of fission events isn't high enough, then no amount of scaling will ever produce more energy than it consumes (e.g. a self-sustaining chain reaction).
As in the above experiment, they will have to keep injecting energy (e.g. ultrasound) to keep stimulating a few fission/fussion events.