[offbytwo]

Before anyone comments "fusion is always 10 years away" I'll just say that we've made significant progress in the last 40 years (energy generated by fusion is on par with moore's law) and it is simultaneously the single hardest and the most rewarding engineering problem ever attempted by humans. Any news on this front is good news.

[eesmith]

Here are the two issues I have with your comment.

The phrase "we've made significant progress in the last X years" has been used for a long time nuclear fusion research. Quote mining from Google Scholar:

2007 - "Significant progress has been made in the area of advanced modes of operation that are candidates for achieving steady state conditions in a fusion reactor." https://inis.iaea.org/search/search.aspx?orig_q=RN:38071367

1999 - "Over the past several decades, significant and steady progress has been made in the development of fusion energy and its associated technology and in the understanding of the physics of high-temperature plasmas." - https://e-reports-ext.llnl.gov/pdf/237013.pdf

1981 - "SUBSTANTIAL PROGRESS HAS BEEN MADE IN ACHIEVING THE CONDITIONS NECESSARY FOR FUSION" - https://www.osti.gov/servlets/purl/6040602

As such, the phrase, while true, cannot be used to infer any sort of near-time (within the next few decades) prediction for an effective fusion power system.

Second, I do not like the appeal to Moore's Law because even if true (I don't know the baseline numbers), all you are saying is that there has been an exponential growth over the decades. However, there are many S-curve growth patterns which appear exponential near the start. What is the basis for assuming that nuclear fusion will be like Moore's law, with exponential growth over many decades, and not an S-curve?

For example, from the 1800s to the 1970s we saw huge increases in transport speed; from trains and wooden ships to moon travel and supersonic passenger airlines. Someone in 1965 (ahem, Heinlein) might point to the exponential growth in rocket ships over a single lifetime and easily assume it would result in Moon bases and tourism within another two generations.

Instead, it flattened out.

[offbytwo]

> cannot be used to infer any sort of near-time

It's not meant to, it's meant to dispel the common notion that no progress is being made in this area of research.

And the total power output doesn't need to remain exponential for fusion to be viable, we just need a way to sustain fusion reactions for a long enough period of time (china recently set a record with 101 seconds).

Seriously look into all the work being done on this currently by Government projects and private companies. I'm not saying it'll happen soon but significant progress has indeed been happening for a long time, and is only picking up pace as time goes on. As I said, this is likely the most difficult thing humans have ever attempted.

https://www.iter.org/sci/BeyondITER

[eesmith]

But the quip that "fusion is always 10 years away" is not an expression that no progress is being made. Rather, it's an expression that the most optimistic views for fusion are always for at least 10 years in future, and as we get more understanding of the difficulty, that horizon always stays 10 years away.

I've been following fusion from the sidelines since I first read about it in SciAm in the 1980s.

I think that understanding how the human body (or any complex biological system) works is a more complex project.

[pstuart]

It would be nice if we could get some LFTR action going while we're waiting.

[offbytwo]

Unfortunately people are actively trying to ban nuclear, the safest and cleanest form of energy[1] ever devised.

[1] https://ourworldindata.org/what-is-the-safest-form-of-energy