# Forum > Discussion > Mad Science and Grumpy Technology >  Fusion Update!!

## Cikomyr2

We did it! We have positive ignition!!! 2 Megajoules in, 3 megajoules out!!!

I know we are far from a finished result, but man, its like seeing the first extraplanar flight in human history.

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## Lord Torath

> We did it! We have positive ignition!!! 2 Megajoules in, 3 megajoules out!!!
> 
> I know we are far from a finished result, but man, its like seeing the first extraplanar flight in human history.


I mean, technically, yes.  But really it was more like 300 MJ in, 3.15 MJ out.

I mean, yes, they poured 2.05 MJ worth of lasers directly into the reactor, but it took 300 MJ of energy to create those 2.05 MJ of lasers.  So still a ways to go.  Still, I'm excited!!!
NPR: U.S. reaches a fusion power milestone. Will it be enough to save the planet?

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## veti

Only about another 30 years to go. Same as it has been for the last 50 years.

Fusion might save the planet for our great grandchildren, but for us it's nothing but a distraction.

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## Thomas Cardew

Fun fact: in 2016 the US spent twice as much on peanut subsidies as it did fusion funding. 

That's like complaining that you're no closer to paying your car off when you haven't actually made payments on your car.

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## halfeye

> Only about another 30 years to go. Same as it has been for the last 50 years.


I'm pretty sure I remember it being 50 years to go in 1980.

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## Radar

> Fun fact: in 2016 the US spent twice as much on peanut subsidies as it did fusion funding. 
> 
> That's like complaining that you're no closer to paying your car off when you haven't actually made payments on your car.


Yes, that graph is pretty sad. Fortunately, other countries and some private companies do invest in fusion and we might see something come out of that in just a few years. From classic tokamaks there is ITER, which is pretty much bound to work (the real challenge will be to optimize the design to be commercially viable), and I'd say SPARC is pretty promising as well. The latter is decidedly cheaper and more compact, which kind of means that ITER could become obsolete before it attains full power, but this would actually mean the project was a great success as the newer tokamak projects benefit greatly from the work put into ITER. Chinese project is also going forward, but I am not sure how close they are to achieving net energy gain. It is just a matter of time though.

Personally, I hope the compact fusion reactor projects will achieve their goals, but I think that those are less certain than the traditional tokamaks.

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## TaiLiu

I'm not a physicist, so I wonder why successful fusion wouldn't violate conservation of energy or something. Do we have reason to believe that we can do it?

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## NichG

It doesn't violate conservation of energy any more than burning gasoline violates conservation of energy. Different elements have different potential energies, where the potential energy minimum is around Iron and Nickel. So anything fusing lower mass elements upwards towards that point can release energy in the form of the difference of potential. And anything splitting highermass elements downwards towards that point can release energy in the same way. If all you had was Iron-56 or Nickel-62, you basically couldn't do anything. But everything else is potential fuel.

The curve is also a LOT steeper on the 'fusing light stuff up to heavy' side than on the 'splitting heavy stuff down into light' side, and stuff on the lighter side is generally more common (since the heavier stuff is basically only produced in significant quantities in supernovae) so fusion represents a much larger accessible budget of energy. But the energy barrier for fusion is a lot higher than for fission, so its much harder to make happen as well.

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## TaiLiu

> It doesn't violate conservation of energy any more than burning gasoline violates conservation of energy. Different elements have different potential energies, where the potential energy minimum is around Iron and Nickel. So anything fusing lower mass elements upwards towards that point can release energy in the form of the difference of potential. And anything splitting highermass elements downwards towards that point can release energy in the same way. If all you had was Iron-56 or Nickel-62, you basically couldn't do anything. But everything else is potential fuel.
> 
> The curve is also a LOT steeper on the 'fusing light stuff up to heavy' side than on the 'splitting heavy stuff down into light' side, and stuff on the lighter side is generally more common (since the heavier stuff is basically only produced in significant quantities in supernovae) so fusion represents a much larger accessible budget of energy. But the energy barrier for fusion is a lot higher than for fission, so its much harder to make happen as well.


Oh, you're right. The sun undergoes nuclear fusion, doesn't it? So obviously it's not impossible. I don't think about these things very often, so I forget.

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## Willie the Duck

> I'm not a physicist, so I wonder why successful fusion wouldn't violate conservation of energy or something. Do we have reason to believe that we can do it?





> Oh, you're right. The sun undergoes nuclear fusion, doesn't it? So obviously it's not impossible. I don't think about these things very often, so I forget.


Perhaps an analogy would be helpful. Elements lighter then iron-nickel are like romantically minded people (with energy input/output being money or effort) -- they want to couple-up*, but only if they get close, have some momentum towards each other, have some social pressure, or whatnot. A star is like college -- everyone is forced into close proximity with each other, everyone's hot(er) than they otherwise are/will be**, it becomes easy for couples to form (and given the price of food/housing/travel compared to average student-job salary, it's easy for the financial benefits of this to exceed the cost of getting the pair together). Fusion in a reactor is more like dating while out in the adult working world -- people/atoms aren't so close together with pressure and temperature making the coupling easy. Energy and effort (which can be very expensive) can easily bleed off into the surrounding environ because the process can't keep its' momentum as easily (I know I cycled through volunteering and adult ed and online dating and all sorts of fruitless endeavors before my now-wife and I met). Oftentimes coupling does still happen, but the expense to do so can equal or exceed any savings that the coupling causes. Scientists have spent 50 years trying to get those speed dating sessions either cheap enough or effective enough to net a positive. They've made a breakthrough -- the total benefit now exceeds the cost to run the actual events, but not build the venue in which it happens or the VC for the speed-dating company (we're exceeding the cost of running the laser, but not the cost of building them or isolating the hydrogen, etc.). As others have said, scientists have been working on total-system-energy-profit and in 50 years gone from it being 50 years out to being possibly 30 years out. It's progress, and worth noting, but not the amazing breakthrough news outlets are indicating. 
*or form some larger romantic unit, which will be a helpful analogy if we get to trying to discuss 4 x Hydrogen-1 --> He fusion
**obviously not universal, metaphors are hard

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## Eldan

> Only about another 30 years to go. Same as it has been for the last 50 years.
> 
> Fusion might save the planet for our great grandchildren, but for us it's nothing but a distraction.


Yes, but that's because we have barely invested any money in fusion research in the last 50 years. Scientists have been pretty sure about how much it would cost to develop fusion since the 70s. It's not even that much, a few hundred billion.

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## Batcathat

I suspect it's the timetable scaring off investors rather than the price-tag. Even with unlimited funding it'd probably take quite a while and the people with money are probably looking more at the next election and/or fiscal year (I suppose a less cynical interpretation might be that they're looking to solve problems quicker than fusion might, but regardless of the motivation the result is the same).

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## Mastikator

The first nuclear reactor took 20 years to develop, people had no problem investing billions (inflation adjusted) to develop that. We would've had working, commercially viable fusion power plants today if people chose to invest in it.

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## halfeye

> The first nuclear reactor took 20 years to develop, people had no problem investing billions (inflation adjusted) to develop that. We would've had working, commercially viable fusion power plants today if people chose to invest in it.


The first reactor was part of the Manhatten Project, it didn't produce power, but it certainly came into existence pretty fast.

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## Trafalgar

> Perhaps an analogy would be helpful. Elements lighter then iron-nickel are like romantically minded people (with energy input/output being money or effort) -- they want to couple-up*, but only if they get close, have some momentum towards each other, have some social pressure, or whatnot. A star is like college -- everyone is forced into close proximity with each other, everyone's hot(er) than they otherwise are/will be**, it becomes easy for couples to form (and given the price of food/housing/travel compared to average student-job salary, it's easy for the financial benefits of this to exceed the cost of getting the pair together). Fusion in a reactor is more like dating while out in the adult working world -- people/atoms aren't so close together with pressure and temperature making the coupling easy. Energy and effort (which can be very expensive) can easily bleed off into the surrounding environ because the process can't keep its' momentum as easily (I know I cycled through volunteering and adult ed and online dating and all sorts of fruitless endeavors before my now-wife and I met). Oftentimes coupling does still happen, but the expense to do so can equal or exceed any savings that the coupling causes. Scientists have spent 50 years trying to get those speed dating sessions either cheap enough or effective enough to net a positive. They've made a breakthrough -- the total benefit now exceeds the cost to run the actual events, but not build the venue in which it happens or the VC for the speed-dating company (we're exceeding the cost of running the laser, but not the cost of building them or isolating the hydrogen, etc.). As others have said, scientists have been working on total-system-energy-profit and in 50 years gone from it being 50 years out to being possibly 30 years out. It's progress, and worth noting, but not the amazing breakthrough news outlets are indicating. 
> *or form some larger romantic unit, which will be a helpful analogy if we get to trying to discuss 4 x Hydrogen-1 --> He fusion
> **obviously not universal, metaphors are hard


So you are saying that scientists should inject alcohol, Viagra, and Barry White music into the reactor to increase energy output?

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## TaiLiu

> Perhaps an analogy would be helpful. Elements lighter then iron-nickel are like romantically minded people (with energy input/output being money or effort) -- they want to couple-up*, but only if they get close, have some momentum towards each other, have some social pressure, or whatnot. A star is like college -- everyone is forced into close proximity with each other, everyone's hot(er) than they otherwise are/will be**, it becomes easy for couples to form (and given the price of food/housing/travel compared to average student-job salary, it's easy for the financial benefits of this to exceed the cost of getting the pair together). Fusion in a reactor is more like dating while out in the adult working world -- people/atoms aren't so close together with pressure and temperature making the coupling easy. Energy and effort (which can be very expensive) can easily bleed off into the surrounding environ because the process can't keep its' momentum as easily (I know I cycled through volunteering and adult ed and online dating and all sorts of fruitless endeavors before my now-wife and I met). Oftentimes coupling does still happen, but the expense to do so can equal or exceed any savings that the coupling causes. Scientists have spent 50 years trying to get those speed dating sessions either cheap enough or effective enough to net a positive. They've made a breakthrough -- the total benefit now exceeds the cost to run the actual events, but not build the venue in which it happens or the VC for the speed-dating company (we're exceeding the cost of running the laser, but not the cost of building them or isolating the hydrogen, etc.). As others have said, scientists have been working on total-system-energy-profit and in 50 years gone from it being 50 years out to being possibly 30 years out. It's progress, and worth noting, but not the amazing breakthrough news outlets are indicating. 
> *or form some larger romantic unit, which will be a helpful analogy if we get to trying to discuss 4 x Hydrogen-1 --> He fusion
> **obviously not universal, metaphors are hard


Thanks, this is really helpful!

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## Radar

> The first nuclear reactor took 20 years to develop, people had no problem investing billions (inflation adjusted) to develop that. We would've had working, commercially viable fusion power plants today if people chose to invest in it.


That was sadly because the reason for investment was getting a new weapon of mass destruction. Nuclear power plants were just a byproduct of the need for plutonium production.

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## Dragonus45

Somehow despite the ever growing push for more energy grids to go green we are still just ignore the greenest energy of all, nuclear. I hope that when fusion starts to look more like a reality we don't flake out on it as well.

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## Radar

> Somehow despite the ever growing push for more energy grids to go green we are still just ignore the greenest energy of all, nuclear. I hope that when fusion starts to look more like a reality we don't flake out on it as well.


In general nuclear power is viewed through Chernobyl and Fukushima incidents and for some pro-green movements also by a connection with nuclear weapons. On top of that, people view nuclear waste disposal as an unsolvable issue, which is very much not the case. It is not easy to go against that.

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## Rynjin

> In general nuclear power is viewed through Chernobyl and Fukushima incidents and for some pro-green movements also by a connection with nuclear weapons. On top of that, people view nuclear waste disposal as an unsolvable issue, which is very much not the case. It is not easy to go against that.


People always tout just shooting the waste into space as a nonviable solution due to cost, but I'm genuinely wondering what the long term math looks like on money saved on energy production over time vs needing to launch radioactive goo into space once every decade, 50 years, arbitrary time interval.

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## Radar

> People always tout just shooting the waste into space as a nonviable solution due to cost, but I'm genuinely wondering what the long term math looks like on money saved on energy production over time vs needing to launch radioactive goo into space once every decade, 50 years, arbitrary time interval.


Not sure really, but we have decidedly better options on the table. One of my favorite are fast neutron reactors capable of using what is now a waste as fuel or at least burn through the depleted fuel rods along with their regular fuel. This way one can get rid of the most problematic waste (both by radioactivity and total mass). Whatever else we need to store away as far easier to deal with and could probably be dealt with in a similar manner.

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## Mastikator

> Somehow despite the ever growing push for more energy grids to go green we are still just ignore the greenest energy of all, nuclear. I hope that when fusion starts to look more like a reality we don't flake out on it as well.


That's hardly fair. Everything but coal is ignored. Sadly. Renewables make big media appearances, but it comes time to build a new powerplant, it's always coal o'clock.

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## Telok

> That's hardly fair. Everything but coal is ignored. Sadly. Renewables make big media appearances, but it comes time to build a new powerplant, it's always coal o'clock.


More profits this decade and a "somebody else's problem" the next five decades beats lower total amortized production, health, & environmental costs on over 50 years. Unregulated industries cost shifting the pollution effects onto the public for the win.

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## Vahnavoi

> People always tout just shooting the waste into space as a nonviable solution due to cost, but I'm genuinely wondering what the long term math looks like on money saved on energy production over time vs needing to launch radioactive goo into space once every decade, 50 years, arbitrary time interval.


Launching any waste out of a gravity well is completely idiotic and the idea is a by-product of people not doing math and vastly overestimating how problematic nuclear waste actually is.

Firstly, it is always more cost-effective to put depleted fuel rods in a metal canister inside a cave, than it is to put them in a rocket. By several orders of magnitude. Solid radioactive materials (if it's goo, somebody is doing something very wrong) are more containable than carbon dioxide or coal dust emissions, so storing them on Earth is safe enough.

Secondly, a lot of the waste is recyclable. A depleted uranium rod has upwards of 90% of its energetic potential still left, improvements in technology may thus change "waste" back into viable fuel. Other uses (medical, military etc.) are also possible. Shooting "waste" into space would actively deprive Earth of a limited resource.

Thirdly, a single launch going badly would turn neatly contained solid waste into tiny widespread fragments. This would, likely, be worse than all nuclear incidents to date. It's questionable if there's any fail state of Earth-bound containment methods that would be anywhere near as bad, short of outright malicious military action.

There's no good reason to ever do this.

---

As for the main topic, I'm not particularly hopeful. I calculated over ten years ago how many new fusion reactors would have to be built to cover projected increases in energy demand. Also did the same for new fission reactors.

The math worked out to tens of fusion reactors, or hundreds of fission reactors, yearly. From 2010.

Nobody has been doing that. Nobody is doing that. Yes, the technological hurdles are being solved one by one. But those technological hurdles were solved for fission decades ago, and lack of political goodwill caused that technology to go underutilized, to the point where there will likely be a global energy crisis or two before fusion becomes commercially viable.

Point being, even if the technology exists, it doesn't mean the political, societal, industrial and logistical conditions for it to become widespread will follow. On paper, Rome had the groundwork for the steam engine figured out two thousand years ago, but the economic incentive to develop it didn't exist. So they remained a pre-industrial civilization and eventually collapsed.

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## Gnoman

> On paper, Rome had the groundwork for the steam engine figured out two thousand years ago, but the economic incentive to develop it didn't exist. So they remained a pre-industrial civilization and eventually collapsed.


This is a myth. The aeolipile was nothing more than a toy, trying to get any real work out of such a design is scientifically impossible. Even the very simple 17th and 18th century engines, which were only worth using because you could power them with coal from the mine you were draining with them, generated higher pressures that could be handled with Greek or Roman materials science. It was not until modern steel in the 19th century that a general-purpose steam engine could be built.


As for the rest, we are not adding the equivalent of "hundreds" of fission reactors to the power grid from all sources every year. Not even close. _One_ fission plant going into operation this year is enough to meet nearly 1/3 of the power usage for the entire country it is built in. Had a hundred such plants been built each year since 2010, most would now be idle due to lack of demand.

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## snowblizz

> People always tout just shooting the waste into space as a nonviable solution due to cost, but I'm genuinely wondering what the long term math looks like on money saved on energy production over time vs needing to launch radioactive goo into space once every decade, 50 years, arbitrary time interval.


What is the difference between a rocket filled with (partially) spent nuclear material and a nuclear missile... not much for the people around the point of impact. Imagine if all those failed rocket launches of Space-X and Nasa also spread radioactive materiel each time. Almost all of the nuclear waste issues comes down to "how can we make this so safe failure is not an option". The cost of "it cannot be allowed to happen under any circumstances" is basically unlimited. Which is where currently nuclear waste disposal sits. It can't be allowed to have any failure points which makes the cost of disposing of it effectively infinite. And no one wants to take the responsibility and finance burden of the long term solution.

I don't have any problem of nuclear energy, but even I baulk at the idea that the solution to it is supposed to be launching nuclear missiles and hope they don't come back. Because you can't convince me I am not in the target area.

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## Gnoman

> What is the difference between a rocket filled with (partially) spent nuclear material and a nuclear missile... not much for the people around the point of impact. Imagine if all those failed rocket launches of Space-X and Nasa also spread radioactive materiel each time. Almost all of the nuclear waste issues comes down to "how can we make this so safe failure is not an option". The cost of "it cannot be allowed to happen under any circumstances" is basically unlimited. Which is where currently nuclear waste disposal sits. It can't be allowed to have any failure points which makes the cost of disposing of it effectively infinite. And no one wants to take the responsibility and finance burden of the long term solution.
> 
> I don't have any problem of nuclear energy, but even I balk at the idea that the solution to it is supposed to be launching nuclear missiles and hope they don't come back. Because you can't convince me I am not in the target area.


Radioactive waste does not create a nuclear weapon. A crashed load of radioactive waste is also a "clear the area and sweep with a Gieger counter" situation, nothing particularly serious unless you get hit by something big enough to be a kinetic hazard. This is irrelevant here because launching the waste (which is both far less dangerous and produced in far less quantity than people think) is stupid, but would matter if an energy-orb powered probe or ship were to crash.

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## Eldan

Space launches are still incredibly expensive. The cost of an Ariane Launch is 100-200 million dollars, for between 4 and 9 tons of cargo, depending on the exact type. 
That's to low Earth orbit, which would be far too close for radioactive waste. Too big a risk it would come back down eventually, or collide with something. 
Higher orbits are exponentially more expensive, and getting out of Earth's gravity well would be in the billions, for a few tons.
We produce about 2000 tons of radioactive waste.
Per year.

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## Sean Mirrsen

> Somehow despite the ever growing push for more energy grids to go green we are still just ignore the greenest energy of all, nuclear. I hope that when fusion starts to look more like a reality we don't flake out on it as well.


Russians don't ignore it. We've closed the nuclear fuel cycle. The already operating BN series and the in-development BREST series reactors will (hopefully) form the backbone of our clean, renewable nuclear power. And we're exporting our VVERs to whoever asks.

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## Mastikator

> Space launches are still incredibly expensive. The cost of an Ariane Launch is 100-200 million dollars, for between 4 and 9 tons of cargo, depending on the exact type. 
> That's to low Earth orbit, which would be far too close for radioactive waste. Too big a risk it would come back down eventually, or collide with something. 
> Higher orbits are exponentially more expensive, and getting out of Earth's gravity well would be in the billions, for a few tons.
> We produce about 2000 tons of radioactive waste.
> Per year.


Not to mention that the high level radioactive waste might become viable fuel in the future when and if we develop the technology to recycle it. It would be a terrible waste to get rid of it even if the space option wasn't incredibly dangerous, expensive and not possible.

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## thatSeniorGuy

Kurzgesagt recently did a video on why launching nuclear waste into space is on non-starter.

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## Vahnavoi

> This is a myth. The aeolipile was nothing more than a toy, trying to get any real work out of such a design is scientifically impossible. Even the very simple 17th and 18th century engines, which were only worth using because you could power them with coal from the mine you were draining with them, generated higher pressures that could be handled with Greek or Roman materials science. It was not until modern steel in the 19th century that a general-purpose steam engine could be built.


The point I am making that people looking at our century in the future might be saying similar things when asked why we didn't get widespread fusion power, despite, on paper, having the basics figured out.




> As for the rest, we are not adding the equivalent of "hundreds" of fission reactors to the power grid from all sources every year. Not even close. _One_ fission plant going into operation this year is enough to meet nearly 1/3 of the power usage for the entire country it is built in. Had a hundred such plants been built each year since 2010, most would now be idle due to lack of demand.


Last I checked, there's more than one country in the world. You also didn't specify how much power this new plant is supposed to produce, so I can't compare it to the assumptions made in my old calculation. As such, it's not much of a refutation of the overall point. If you do know how much power the new reactor is supposed to produce, it's possible to make a new projection, starting from now, for how many similar reactors would need to be built to cover projected energy demands. I'm fairly confident we'll still find out no-one is building enough new reactors, and trying to cover the same ground with fusion is still nowhere in sight.

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## Eldan

The Romans didn't have the basics figured out, though. They didn't have any material they could have used to make a pressure vessel. And steam engiens are nothing _but_ pressure vessels. This would be like if we claimed to have figured out the basics of fusion, but we didn't know what hydrogen or helium were.

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## Vahnavoi

You are simply repeating what Gnoman said, and what I already conceded.

Since apparently I need to, let me explain why I chose that point comparison: people now look at aeolipile and see it as an early example of steam power, and that prompts them to ask things like "if ancient people had that, why didn't they go through an industrial revolution?" . That's all. You l knew that. You know a laundry list of reasons why it couldn't happen. I knew that.  Nitpicking the comparison doesn't refute the overall point.

On a side note, there still are problems with materials needed to contain a lasting fusion reaction. That would the proper comparison for the difficulties Romans would've had building the right kind of pressure vessel. That's where you can tell whether we're, relatively, worse or better at this point.

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## Gnoman

> The point I am making that people looking at our century in the future might be saying similar things when asked why we didn't get widespread fusion power, despite, on paper, having the basics figured out.


That's akin to saying the ancient Chinese had the "basics figured out" for putting a man on the moon because they had a few simple gunpowder rockets. The ancient Greek and Roman "steam engines" aren't the basics of modern steam power - they're "you might be able to see the basics from here in a fever dream".

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## Telok

Folks, please drop the obsessive ranting over analysis of an imperfect example.

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## Radar

> Folks, please drop the obsessive ranting over analysis of an imperfect example.


But... but... it's the Internet! Also, coconuts.

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