3 ms·

In addition to what you said, I think our perception of the Manhattan and Apollo projects is skewed by survivorship bias [1]. These projects kept hitting milest

In addition to what you said, I think our perception of the Manhattan and Apollo projects is skewed by survivorship bias [1]. These projects kept hitting milestones, so they kept getting additional funding, until their successful final delivery. It's quite likely that many, many more projects (laser weapons, scramjets, ekranoplanes) experienced a funding flatline like the fusion famous graph, simply because their milestones proved elusive. It's better to deliver results than excuses and delays. [1] https://xkcd.com/1827/ https://xkcd.com/1827/

Iv 7y ago
Manhattan and Apollo also had the objective to defeat an enemy. A much stronger motivation to spend public funds than saving climate. I am expecting that if China announced a working fusion reaction tomorrow, US would put the funding and have one in only 5-6 years.
adrianN 7y ago
The most important fusion power metric has actually improved really fast, despite the abysmal funding situation: https://imgur.com/BN0pz https://imgur.com/BN0pz
- credit_guy 7y ago
  Very interesting graph, thanks for sharing. I guess the point of the graph is that the progress in fusion has been steady and followed an exponential low for 3 decades, in a way that matches the Moore law. If I were a politician in 2019 with the right to sign funding and I see this graph, I cut all funding right away. Here's why: * based on this graph, a simple extrapolation by only 2 years show the achievement of the commercial reactor in 2005. Where's the commercial reactor 14 years later? We are instead only 6.5 years away before pushing a certain button at ITER, which has some type of significance that's not entirely clear * at least one point on this graph is "cooked": the JT-60U that appears to cross the breakeven point at some point prior to 2000. Here's what wikipedia [1] says about this: "During deuterium (D–D fuel) plasma experiments in 1998, plasma conditions were achieved which would have achieved break-even—the point where the power produced by the fusion reactions equals the power supplied to operate the machine—if the D–D fuel were replaced with a 1:1 mix of deuterium and tritium (D–T fuel)." What's the point of the "figure-of-merit" graph then? It projects when we'll get to breakeven or commercial, only to find there that you need to make another tiny change (i.e. substitute D with T) that will take 30 more years? [1] https://en.wikipedia.org/wiki/JT-60#JT-60U_(Upgrade) https://en.wikipedia.org/wiki/JT-60#JT-60U_(Upgrade)
  - adrianN 7y ago
    Berlin has been building an airport for fifteen years now. Building large things takes time, especially if it's supposed to be an international collaboration.
  - petschge 7y ago
    ITER is far behind that growth curve because its cost is beyond what a university or national research lab is filling to fund. To unlike a lot of other projects before it, it is this massively political beast. Involving politician by itself introduces at least a decade of delay. The triple product is the correct figure of merit and JT-60U did great there. But it was a plasma experiment and did not have the shielding that is necessary to run it with D-T fuel that produces a lot of neutron during fusion. But we know a lot more about neutron fielding than we know about magnetically confined fusion. Improving the plasma handling and the triple product is much harder than adding shielding.
    - credit_guy 7y ago
      > The triple product is the correct figure of merit and JT-60U did great there. Look. If you have a graph where you show a certain point called "figure-of-merit" being above a so called break-even point, every layperson in this world will assume that you get more energy out than you put in. If you then say that it's breakeven for a different reaction, they'll either question your sanity, or they'll accuse you of bait-and-switch. If you don't understand why you get your funding cut, you'll think life is unjust or cruel. Other people will nod sympathetically when you'll complain of the unfairness of this world , but secretly they'll disagree with you.
      - petschge 7y ago
        Well, lay people have no clue. And probably should not be in charge of funding.
        credit_guy 7y ago
        The money comes from them, you know? One way or another, they are in charge of funding, and the way to help them make better decision is to be truthful, not to massage the message (you want to tell me it's really ok to compare a figure of merit for a reaction with the breakeven point for another reaction? * ) So, here's what Zubrin has to say about nuclear fusion and ITER [1]: "While, driven by international rivalry, the world's national fusion programs did advance forcefully between 1960 and 1990, the decision to consolidate all of them into a unified global effort to build the International Experiment Reactor (ITER) has caused nearly all progress to screech to a halt since the 1990s." Why did this happen? Could it be because laypeople in charge of funding listened to scientists lobbying for a cool (and expensive) magaproject? [1] https://www.amazon.com/dp/B07HDSSKHJ/ref=dp-kindle-redirect?_encoding=UTF8&btkr=1 https://www.amazon.com/dp/B07HDSSKHJ/ref=dp-kindle-redirect?... ( * ) in all fairness, you only argued that the figure-of-merit it a good metric, which I don't contest.

Iv 7y ago

Manhattan and Apollo also had the objective to defeat an enemy. A much stronger motivation to spend public funds than saving climate. I am expecting that if China announced a working fusion reaction tomorrow, US would put the funding and have one in only 5-6 years.

adrianN 7y ago

The most important fusion power metric has actually improved really fast, despite the abysmal funding situation: https://imgur.com/BN0pz https://imgur.com/BN0pz

credit_guy 7y ago
Very interesting graph, thanks for sharing. I guess the point of the graph is that the progress in fusion has been steady and followed an exponential low for 3 decades, in a way that matches the Moore law. If I were a politician in 2019 with the right to sign funding and I see this graph, I cut all funding right away. Here's why: * based on this graph, a simple extrapolation by only 2 years show the achievement of the commercial reactor in 2005. Where's the commercial reactor 14 years later? We are instead only 6.5 years away before pushing a certain button at ITER, which has some type of significance that's not entirely clear * at least one point on this graph is "cooked": the JT-60U that appears to cross the breakeven point at some point prior to 2000. Here's what wikipedia [1] says about this: "During deuterium (D–D fuel) plasma experiments in 1998, plasma conditions were achieved which would have achieved break-even—the point where the power produced by the fusion reactions equals the power supplied to operate the machine—if the D–D fuel were replaced with a 1:1 mix of deuterium and tritium (D–T fuel)." What's the point of the "figure-of-merit" graph then? It projects when we'll get to breakeven or commercial, only to find there that you need to make another tiny change (i.e. substitute D with T) that will take 30 more years? [1] https://en.wikipedia.org/wiki/JT-60#JT-60U_(Upgrade) https://en.wikipedia.org/wiki/JT-60#JT-60U_(Upgrade)
- adrianN 7y ago
  Berlin has been building an airport for fifteen years now. Building large things takes time, especially if it's supposed to be an international collaboration.
- petschge 7y ago
  ITER is far behind that growth curve because its cost is beyond what a university or national research lab is filling to fund. To unlike a lot of other projects before it, it is this massively political beast. Involving politician by itself introduces at least a decade of delay. The triple product is the correct figure of merit and JT-60U did great there. But it was a plasma experiment and did not have the shielding that is necessary to run it with D-T fuel that produces a lot of neutron during fusion. But we know a lot more about neutron fielding than we know about magnetically confined fusion. Improving the plasma handling and the triple product is much harder than adding shielding.
  - credit_guy 7y ago
    > The triple product is the correct figure of merit and JT-60U did great there. Look. If you have a graph where you show a certain point called "figure-of-merit" being above a so called break-even point, every layperson in this world will assume that you get more energy out than you put in. If you then say that it's breakeven for a different reaction, they'll either question your sanity, or they'll accuse you of bait-and-switch. If you don't understand why you get your funding cut, you'll think life is unjust or cruel. Other people will nod sympathetically when you'll complain of the unfairness of this world , but secretly they'll disagree with you.
    - petschge 7y ago
      Well, lay people have no clue. And probably should not be in charge of funding.
      - credit_guy 7y ago
        The money comes from them, you know? One way or another, they are in charge of funding, and the way to help them make better decision is to be truthful, not to massage the message (you want to tell me it's really ok to compare a figure of merit for a reaction with the breakeven point for another reaction? * ) So, here's what Zubrin has to say about nuclear fusion and ITER [1]: "While, driven by international rivalry, the world's national fusion programs did advance forcefully between 1960 and 1990, the decision to consolidate all of them into a unified global effort to build the International Experiment Reactor (ITER) has caused nearly all progress to screech to a halt since the 1990s." Why did this happen? Could it be because laypeople in charge of funding listened to scientists lobbying for a cool (and expensive) magaproject? [1] https://www.amazon.com/dp/B07HDSSKHJ/ref=dp-kindle-redirect?_encoding=UTF8&btkr=1 https://www.amazon.com/dp/B07HDSSKHJ/ref=dp-kindle-redirect?... ( * ) in all fairness, you only argued that the figure-of-merit it a good metric, which I don't contest.