I enjoy the joke about the perpetually shifting fusion acquisition time frame, but it would be fair to add that in terms of actual funding, we have been under the "fusion never" level. I feel like the context for the saying has always been that the proper financing assumption holds.

Wake me when the first power station is being built.

Perhaps this time I won’t fall for the Gell-Mann Amnesia effect…

The old superconductors typically used in this kind of magnets have been pushed to the limit already in Nuclear Magnetic Resonance, ~23 Tesla is the strongest existing commercial one and this seems to be a limit for that technology. The first NMR magnets that use YBCO are expected in the next years as far as I remember, I don't think any exist yet.

It's pretty like the idea with data analytics or software ; if you can do an iteration / update by yourself in 10 minutes you will be able to solve the problem (for reasonable problems) in a few weeks for sure. If you need to spend a month assembling the data and compiling the code before you can commit a change you are simply not going to ever be able to make progress.

There are a lot of problems to deal with eg see "Fusion reactors: Not what they’re cracked up to be" https://thebulletin.org/fusion-reactors-not-what-they%E2%80%... There's also a Reddit discussion of that saying the problems aren't quite so bad https://www.reddit.com/r/fusion/comments/67rqqg/fusion_react...

If I were a politician I'd vote for subsidising the thing by say buying the electricity at 30c/kWh to advance human understanding, so I think it could be built. I think MIT estimated $5bn + to build a 200MW generator which is not a huge amount in government terms.

Coupled with emerging energy storage it seems like cheap energy is due to come long before fusion

Fusion could potentially be extremely compact, extremely energetic, and not _that_ expensive to set up relative to how much power you get out of it. Renewables could make energy _cheap_, but fusion could make it practically _free_.

They are cheaper to set up at scale, but also work very well in a micro production / distributed environment (albeit slightly more expensive)

I understand your argument about space, you need a lot of space to harness energy, but we're now starting to see deep sea wind turbines, and Earth happen to have quite a bit of windy areas above deep sea.

Just the North sea itself could cover a massive portion of Europe's energy production (double digit)

Just, fusion could be better _still_, if it gets off the ground. That's not a reason to not focus on what we _can _do now, though.

Fission already beats renewable by a good margin and Fusion puts some on top of that.

The fuel for fusion is incredibly cheap; hydrogen and helium, the most common elements in the universe. Easily obtained from solar wind if we find the amount on earth is lacking.

Additionally, Fusion does not produce any dangerous waste. Any byproducts that are radioactive decay quickly.

Fusion is also a lot safer than Fission since the reaction cannot exist outside reactor conditions while a uranium rod will happily go prompt critical if it gets the chance.

Fusion is cheap energy.

This is not true, I don't think people realise how much the renewable prices are currently dropping: https://www.theguardian.com/environment/nils-pratley-on-fina...

I can see the benefit of fusion though I'm not very convinced by the density argument (we do have space to put solar on our roofs, wind on our shores, batteries in our basements and distribution points, and plenty of spots to pump geothermal)

I'm not seeing any Solar Panels or Wind Turbines on the market that can output 80 TJ per Kilogram of Weight over their lifetime.

The article you linked talks about Energy Cost, which is another issue. Though considering Hydrogen and Helium are the most abundant resources in the universe, I'm not holding my breath for any renewable resources consistently beating that.

Cost =/= Density, otherwise we'd be powering electric cars with AAA batteries.

>(we do have space to put solar on our roofs, wind on our shores, batteries in our basements and distribution points, and plenty of spots to pump geothermal)

Yes but the point is that fusion requires a lot less space for a lot more power, doesn't depend on the weather or surrounding geology and is 100% clean.

Uranium is somewhat difficult to obtain; you have to mine it from deep under (using what amounts to slave labor), clean the ore and then carefully and thoroughly enrich it (238 is almost unusuable in reactors, you need 235, which is only present in a small fraction of the ore).

On the other hand, getting hydrogen can be achieved with electrolysis (electrolysis requires less energy than the fusion reaction produces), various other chemical processes or simply solar wind.

Hydrogen is the most common material in the universe, it will and can outpace any other energy source.

Renewables are simply different methods for capturing energy from the fusion happening in the sun with some efficiency.

China is building tons of new coal plants to cover its current needs. It doesn't seem that renewables are that great, when not subsidized (which is the only true measure of effectivity)

>for an offshore wind turbine 0.57 years of expected average energy production are necessary to recover all the energy consumed for manufacturing, operation, transport, dismantling and disposal https://www.wind-energy-the-facts.org/energy-balance-analysi...

Not so sure about this one: https://www.theguardian.com/environment/2017/mar/22/coal-pow...

Sure they are still building but at a rate that has been drastically shaken up by both the price of renewables and their own environmental policies.

Now regarding the environmental impact of producing solar panels and wind turbines, they clearly are carbon negatives

http://www.drawdown.org/solutions/electricity-generation/roo...

http://www.drawdown.org/solutions/electricity-generation/win...

Though I'm sure they can't have no-impact, you will get some other form of pollution, but at the moment what matters most if reducing our greenhouse effect. It's cheap, it's already there so there's no reason to delay it I think.

The answer to that is obvious: yes. So why wouldn’t we need money?

Basically the price (demand) for hardware goes up and should equilibriate when it reaches the previous cost of energy.

GAI and fusion are different issues in that we have clear elementary understand of fusion (and a large chunk of the technology worked out). We have little to no understanding of cognition and much of the technology that we use for AI now may (or may not) prove to be irrelevant to GAI.

I'll challenge that, because I think tribalism (living in small groups) is the way more akin to our genes. And much from the rising mental problems of humans today comes from living on your own in a big anonymous pool of strangers.

But those small groups could then indeed work (more) together for the common good.

Why?

I didn't say we should live stone age style. And using technology is very akin to our genes, afaik. So I don't see any problems with that. What matters more than the tools are the social interactions I believe. And there we could do better.

But .. actually there is also enough space on earth left ... poplated areas are very dense compared to big open lands.

In short, I'd like humans to just get on with each other and treat the world we share with other species with greater respect. If that puts me in a tribe, then so be it!

https://arxiv.org/pdf/1409.3540.pdf

the concept (which would produce 190MW(e)) uses 90 tonnes of beryllium.

According to the USGS, the current total world annual production of Be is 220 tonnes, and total global resource is estimated at 100,000 tonnes.

The world uses ~20 TW of primary energy, so roughly 100,000 ARC reactors would be needed to supply the world, using about 100x as much Be as the estimated amount available for mining.

Unless Be supplies can be drastically increased, this concept is at best a niche player.

There are lots of companies in the game now.

Tri Alpha Energy, General Fusion, Lockheed Martin and there are quite a few more.

There is the Wendelstein 7X stellarator and ITER.

The increase in fusion magnetic energy has actually been faster than Moore's law.

See this video at 18:30 https://www.youtube.com/watch?v=KkpqA8yG9T4&t=3990s

The massive improvements in superconductive magnets are really making a huge impact. Check out ARC and SPARC from MIT.

Humanity is going to get usable energy generated from fusion.

When I was in high school, 45 years ago, I visited prospective colleges. Some grad students were discussing the fusion work they were doing, in a big building, with lots of shiny hardware. They probably told me that practical fusion was 15 years away.

Humanity is going to get usable energy generated from fusion.

Yeah I heard that in high school. I'm now retired and am still hearing it. Still, stranger things have happened. The Chicago Cubs won the World Series a few years ago!

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

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.

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.

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?

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.

However there was the space race and lots of funds were allocated to going to the Moon.

We don't do a lot of things, at least in the modern US, because we have tie economic incentive to everything vs doing for society, even at a 'loss'.

At least money is being raised and people are trying, it's easy to be a cynic about something that's been promised as around the corner for the last 50 years.

Fusion with net positive output would change everything for the world. Really hope they get over the line.

So it's coming along even if commercial viability may still be a while off.

And this article seems to say, well it's.......

By the way, "on the brink of" in the title is pretty stupid.

I'd suggest the optimistic estimates are both for scientists and investors. Optimism is used as a fuel to keep scientists going when the future is uncertain, and any breakthrough, however small, is a chance to recharge that fuel. On the other side, (in our society) scientific research requires funding. It's easier to acquire funding if you suggest the research may take 20 years rather than suggesting it'll take 100 years. This also encourages scientists to be optimistic in their predictions, as if they aren't optimistic they risk losing their funding, which greatly reduces the chance of rapid progress.

For those reasons, I'd suggest these long estimates (as a definition of 'long', let's say in this case anything over 5 years) are just tools that help to get the work done, rather than being something with a high probability of being true.

Scale that up, and...

Setting short term targets is only realistic when you're doing something that either has been done before or where it's a variation on something that has been done before. Perhaps you underestimate the time it takes to do something by being unaware of the underlying complexity of a task (or by telling people what they want to hear, if they can't handle pessimistic estimates), but they still have a reasonable chance of being completed on time.

Long term targets work differently. If you want the time taken to be as short as possible, and you still give an estimate within a window of time which you have little to no hope to predict, you're basically saying "I don't know".

To put it another way, I could have a reasonable guess at what I'd be doing one week from now. On the other hand, I don't really know what I'll be doing 20 years from now. Any estimates I put within a range that is outside my ability to predict would basically boil down to me implying I haven't got a clue. With that said, I'd still put a timescale on an baseless estimate if it served a purpose. It's the purpose behind pulling the number out of thin air which is the point I was trying to highlight.

The 10s runtime is surprisingly close to a continuum runtime btw.

But I'm wondering how relevant fusion is to reverse climate change. It seems like renewables and storage are already fitting the bill, at a much lower cost.

Edit: happy to hear any arguments

I certainly think we should build renewables as fast as we can, because they're available now and a long way from the market share that requires a lot of expensive storage. But down the road, it's entirely possible that advanced nuclear power sources, whether fusion or advanced fission like MSRs, will be more economical than building enormous amounts of battery storage. (We do have cheap hydro storage but that's geographically limited.)