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US Teases 'Major' Science News Amid Fusion Energy Reports

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Re: US Teases 'Major' Science News Amid Fusion Energy Reports

#41

Post by jfengel »

P5fRxh5kUvp2th wrote: post #32
jacknews wrote: post #20

Is it really a 'scientific breakthrough' if it's just that they've firing fusion shots with 'net positive energy output'? Good work, but IMHO we're still a long way from using fusion for energy, if ever, even if only because it will be so expensive to build and run these ultra-high-tech plants. But also because of all the downsides of D-T fusion, like, where is the tritium, and that most of the energy comes of as fas…

how do you run before you can walk, and what has this level of cynicism done for you in life?

It saves time. The most you can actually get from such an announcement is to slightly update your priors. It doesn't affect your actions at all. So you see it, note it, become slightly miffed that the Internet will be full of comments that think it's a bigger deal than it is, and move on with your life.

The cynicism serves as a mental balance to the hype that might otherwise tempt you to spend more time on this than it merits.

Re: US Teases 'Major' Science News Amid Fusion Energy Reports

#42

Post by P5fRxh5kUvp2th »

jfengel wrote: post #41
P5fRxh5kUvp2th wrote: post #32

Earlier quoted context omitted.

how do you run before you can walk, and what has this level of cynicism done for you in life?

It saves time. The most you can actually get from such an announcement is to slightly update your priors. It doesn't affect your actions at all. So you see it, note it, become slightly miffed that the Internet will be full of comments that think it's a bigger deal than it is, and move on with your life. The cynicism serves as a mental balance to the hype that might otherwise tempt you to spend more time on this than…

skepticism does that, not cynicism. They're not the same thing.

Re: US Teases 'Major' Science News Amid Fusion Energy Reports

#43

Post by zardo »

Brometheus wrote: post #27
marssaxman wrote: post #25

Earlier quoted context omitted.

So far as I am aware, coal, oil, gas, and nuclear power stations all generate electricity by producing heat, boiling water, and using the steam to spin a turbine. Once you have heat, the rest seems like well-understood industrial technology. Is there something unique about fusion power which makes its heat more difficult to employ?

Yes, the fusion needs "huge" amounts of electrical energy input to happen, be it in the form of lasers like here or in the form of magnetic fields like in iter. In this experiment 2.1 units of input energy produced 2.5 units of output energy. That energy has to be converted to electricity. Conversion looses like 40% of energy (escapes unsused) – so you have produced 1.5 units of electricity from 2.1 units of electric…

It's energy_out/energy_in, but the energy_in is not the total energy used by the experiment, it's the fraction that is transferred to the fusion fuel.

Re: US Teases 'Major' Science News Amid Fusion Energy Reports

#44

Post by jfengel »

P5fRxh5kUvp2th wrote: post #42
jfengel wrote: post #41

Earlier quoted context omitted.

It saves time. The most you can actually get from such an announcement is to slightly update your priors. It doesn't affect your actions at all. So you see it, note it, become slightly miffed that the Internet will be full of comments that think it's a bigger deal than it is, and move on with your life. The cynicism serves as a mental balance to the hype that might otherwise tempt you to spend more time on this than…

skepticism does that, not cynicism. They're not the same thing.

When dealing with news, skepticism and cynicism are practically identical. They're not the same, but cynicism is less effort and achieves similar results.

And it's easily reversed. If this turns out to be useful, you'll get many more chances to re-evaluate.

Re: US Teases 'Major' Science News Amid Fusion Energy Reports

#45

Post by P5fRxh5kUvp2th »

jfengel wrote: post #44
P5fRxh5kUvp2th wrote: post #42

Earlier quoted context omitted.

skepticism does that, not cynicism. They're not the same thing.

When dealing with news, skepticism and cynicism are practically identical. They're not the same, but cynicism is less effort and achieves similar results. And it's easily reversed. If this turns out to be useful, you'll get many more chances to re-evaluate.

I reject your premise that they're "practically identical" and it's going to be on you to show that such a grand claim is true.

skepticism is requiring facts, cynicism is a generally negative outlook.

You can change skepticism by producing facts, you cannot change cynicism that way.

confusing the two is a very common mistake.

Re: US Teases 'Major' Science News Amid Fusion Energy Reports

#46

Post by greggarious »

Brometheus wrote: post #27
marssaxman wrote: post #25

Earlier quoted context omitted.

So far as I am aware, coal, oil, gas, and nuclear power stations all generate electricity by producing heat, boiling water, and using the steam to spin a turbine. Once you have heat, the rest seems like well-understood industrial technology. Is there something unique about fusion power which makes its heat more difficult to employ?

Yes, the fusion needs "huge" amounts of electrical energy input to happen, be it in the form of lasers like here or in the form of magnetic fields like in iter. In this experiment 2.1 units of input energy produced 2.5 units of output energy. That energy has to be converted to electricity. Conversion looses like 40% of energy (escapes unsused) – so you have produced 1.5 units of electricity from 2.1 units of electric…

>In this experiment 2.1 units of input energy produced 2.5 units of output energy. That energy has to be converted to electricity. Conversion looses like 40% of energy (escapes unsused) – so you have produced 1.5 units of electricity from 2.1 units of electricity input.

Thanks for distilling this into one three simple sentences, I know from my brief career in science policy how hard that can be. (You should write 1 pagers for the US Congress :-))

To get back on topic:

So basically, if I'm understanding you correctly: this is an increase in efficiency but not one such that it makes sense economically to generate power in this way?

Is this a large jump in efficiency from previous attempts?

The reason I ask is that I know physics can be incremental, so I don't want to detract from the contributions of the authors... and by all means, it's the type of thing I'd expect to see on HN if so and I'm glad it was shared.

I was just surprised to see many more mainstream sites, geared towards a more general audience, running stories about what I'd expect to be more of a niche discovery.

(Possibly as more of a geopolitics thing -- much like if someone is arrested no one recalls with equal vigor when the charges are dropped, a PR-y article about a minor but important discovery can influence public opinion and be a tool of geopolitics.)

Re: US Teases 'Major' Science News Amid Fusion Energy Reports

#48

Post by greggarious »

Symmetry wrote: post #26
marssaxman wrote: post #25

Earlier quoted context omitted.

So far as I am aware, coal, oil, gas, and nuclear power stations all generate electricity by producing heat, boiling water, and using the steam to spin a turbine. Once you have heat, the rest seems like well-understood industrial technology. Is there something unique about fusion power which makes its heat more difficult to employ?

It's not that it's difficult, its just that it's not perfectly efficient. So once you include the inefficiencies of the heat engine it not necessarily producing energy on net. But there are also some engineering challenges to work out in employing heat generated like this to drive a heat engine, at least with somethings decent like 30% efficiency.

Is ~30% what other sources achieve?

Re: US Teases 'Major' Science News Amid Fusion Energy Reports

#49

Post by Symmetry »

greggarious wrote: post #48
Symmetry wrote: post #26

Earlier quoted context omitted.

It's not that it's difficult, its just that it's not perfectly efficient. So once you include the inefficiencies of the heat engine it not necessarily producing energy on net. But there are also some engineering challenges to work out in employing heat generated like this to drive a heat engine, at least with somethings decent like 30% efficiency.

Is ~30% what other sources achieve?

Other sources can do better but the problem of transferring heat from plasma erupting in a vacuum chamber lined with mirrors seems really hard to me compared to the problem you have in a natural gas power plant, say, so I'd expect even a well developed laser pulse fusion power plant to have a lower efficiency.
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