51–60 of 141 posts
> First Light has achieved fusion having spent less than £45 million, and with a rate of performance improvement faster than any other fusion scheme in history. I know that technically it's a "scheme", but with the history of this technology they should probably use different language
Earlier quoted context omitted.
'Scheme' in this case is a Britishism, basically meaning a project (not something nefarious).
Is it really unique to Britain? It's the first definition on Wiktionary and it doesn't mention anything about it being regional. Is scheme really only negatively in America?
Scheme itself means the same thing but it's fallen out of use and the only times I've encountered it is when the speaker wants to distance themself from it: get rich quick scheme, hare-brained scheme, nefarious scheme, malicious scheme, etc.
Earlier quoted context omitted.
It's so cool, though. The power of the sun, in the palm of my hand!
Solar panels harness the power of the sun too. Fun fact: The sun's energy density is only a few watts per ton. A thousand-pound chunk of the sun could barely run a flashlight. Practical fusion requires H/He conversion rates exponentially faster than stars. Yes, i meant to say power density rather than energy. My bad.
As a nuclear fusion ignorant, where is the small print here? What's the catch, drawback, issue that it will make actually nonviable ?
Roughly speaking, the catch with every fusion-related "breakthrough" in the past 60+ years is the not-so-slight difference between: - "With a huge research budget, we found a nifty new way to reliably set a few tiny lumps of coal on fire in our lab." and - "We can reliably build useful and practical locomotives, ships, and electrical generating plants which are powered by burning coal... and are long-term economicall…
As a nuclear fusion ignorant, where is the small print here? What's the catch, drawback, issue that it will make actually nonviable ?
Roughly speaking, the catch with every fusion-related "breakthrough" in the past 60+ years is the not-so-slight difference between: - "With a huge research budget, we found a nifty new way to reliably set a few tiny lumps of coal on fire in our lab." and - "We can reliably build useful and practical locomotives, ships, and electrical generating plants which are powered by burning coal... and are long-term economicall…
https://www.mpg.de/18250857/jet-fusion-facility-new-world-en...
The plasma was stable and they could have gone longer except instead of superconductors, JET uses copper coils that would melt if they went longer.
Their input energy was about three times their total output. But fusion output scales with the square of reactor volume and the fourth power of magnetic field strength, and modern REBCO superconductors can support much stronger fields than JET was using.
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I think this misses the most important thing about predictions: * has been "10 years away" for many years: could be tomorrow An example would be "How long before a computer beats a grandmaster at Go?" The answer was "10 years away" for decades, right up to 2015, and then one day in 2016, that day was "today".
>> The answer was "10 years away" for decades, right up to 2015, and then one day in 2016, that day was "today". I've heard this a few times. In 2014 I was doing an MSc in Intelligent Systems ("AI" after the Winter) and Go was discussed in class in the context of Russel and Norvig. I don't remember the tutor saying that beating a grandmaster (? do they have grandmasters in Go?) was "10 years away". I remember him say…
>In early 2014, Coulom's Go-playing program, Crazystone, challenged grandmaster Norimoto Yoda at a tournament in Japan. And it won. But the win came with caveat: the machine had a four-move head start, a significant advantage. At the time, Coulom predicted that it would be another 10 years before machines beat the best players without a head start.
I'm sure there's more to find, but of course google now biases towards the articles about AlphaGo actually winning.
Earlier quoted context omitted.
"Little Boy" the first nuke deployed in Japan was also just a gun, firing a lump of enriched uranium at another lump of enriched uranium at the end of a tube.
I was going to say it fired a slug through a cylindrical piece of material, but decided to verify this on Wikipedia. It turns out: >> For the first fifty years after 1945, every published description and drawing of the Little Boy mechanism assumed that a small, solid projectile was fired into the center of a larger, stationary target.[31] However, critical mass considerations dictated that in Little Boy the larger, h…
Making a nuclear bomb has nothing to do with the knowledge of its' construction. Detailed plans are freely available to anyone who is interested. The reason you can't make a nuke is that the enrichment process of a suitable amount of fissile material requires nation-state level of industrial output. It is physically impossible for a small rogue actor to make a bomb from scratch. Germany during WWII, for example, was far advanced toward a bomb years before the Manhattan project, but their industrial capacity was simply never sufficient to build it.
As a nuclear fusion ignorant, where is the small print here? What's the catch, drawback, issue that it will make actually nonviable ?
The "bullet" is fast enough to compress the gas inside the cube, creating fusion.
It works. But in the scenario it does work, a machine is manually opened, loaded, prepared, and then they do the shot. Whole process takes days to prepare.
For it to be viable they need to do this every five seconds.
That is a hard problem to solve. First lights business model is not to solve that problem, but rather producing the "fuel", the tiny cubes with gas inside.
They say there is many details in how they are built which increases efficiency.
But someone still has to figure out how to build a machine that can continuously reload both the fuel and the bullet.
The amount of cynicism around fusion is stupid. It reminds me a lot of the learned helplessness that surrounded the idea of reusable spacecraft. A little engineering later: https://www.youtube.com/watch?v=sf4qRY3h_eo Fusion is a harder problem than that but we have no physical reason to believe it is not possible and the surrounding technology like compact higher temperature superconductors has advanced significantly…
Cynicism is well justified, given history and the present landscape. Suppose they get this working, and able to produce, what, 300 MW worth of hot neutrons. They have to capture the neutrons and turn them into heat to boil water to drive a turbine to get out 150 MW. Thus, handle the, what, 1000 tons? 10,000 tons? of lithium needed to capture all those neutrons. And, I guess, sieve it for tritium? Maybe chemically sep…
The history, measured by the fusion triple product, is exponential progress on par with Moore's law [1], despite abysmal funding [2].
[1] Figure 1, https://www.scipedia.com/public/Sanchez_2014a
[2] https://hardware.slashdot.org/story/12/04/11/0435231/mit-fus...
The amount of cynicism around fusion is stupid. It reminds me a lot of the learned helplessness that surrounded the idea of reusable spacecraft. A little engineering later: https://www.youtube.com/watch?v=sf4qRY3h_eo Fusion is a harder problem than that but we have no physical reason to believe it is not possible and the surrounding technology like compact higher temperature superconductors has advanced significantly…