Past performance is not indicative of future results.

Sure it is. It is the best indicator we use.

Certificates, diploma, driver license, etc. are all based on that.

Scientific research is inherently a field where progress could be modeled as punctuated equilibria. Just because there are long periods where little progress is made on a hard problem does not mean that it will never be solved, or that the solution is perpetually "15 years away". But it does mean that attempting to linearly extrapolate progress over a period of time is likely to be incorrect.

"where little progress is made on a hard problem does not mean that it will never be solved"

Never said that. But if fusion scientists say since 50+ years, that they are allmost there, then it is a pretty good indicator, that there probably also won't be a working fusion plant in the next 15 year's.

That would be true if we had no other data to go on, but we do: the fusion triple product, which has to exceed a threshold for net power. The JT-60 tokamak in Japan reached a triple product in 1999, using D-D fuel, that would have barely exceeded breakeven if they'd been using D-T. Fifty years ago we were nowhere near that close.

Ha.

Wonder when the first company that was targeting fusion was started.

It seems there weren't any until the 2000s sometime. Now there are lots. People with the money to sink 10s of millions into the idea think that it's close.

Danny Hillis will bet you that someone will do this by 2020:

http://longbets.org/605/

They have lots of skin in the game.

Hi. Fusion company founder from 1995 here (Fiat Lux Research, funded by DFJ). We were probably the first in the internet age, but didn't have a website (stealth mode engaged!). We definitely weren't the first. Companies which were earlier than us that I am aware of include Bogdan Maglich's Migma company (1974), Paul Koloc's Prometheus 2 (1976) and Bussard's EMC2 (1985). You could also include companies with divisions targeting fusion like General Atomics (1974) and ITT (1964).

Wow.

Thanks heaps for that. I had no idea.

What do you think of the new wave of fusion companies? Do you think they will get somewhere?

There is a subreddit for fusion. reddit/r/fusion.

Would you be interested in answering questions, doing a sort of AMA there?

I think this says more about the credulity of VCs and their general failure at anything approaching heavy metal technologies than anything else. Transatomic, a startup which is vastly less ambitious than any fusion startup (molten salt reactors are old tech) is a great example. Big oops on this one.

Tri-Alpha was, as far as I can tell, the most legitimate of the fusion companies. My pal Dave just retired from it; he worked on their data efforts. FWIIW my original comment was quoting him.