Nuclear fusion 'will work' (auto-starting audio) • Hacker News Board

Re: Nuclear fusion 'will work' (auto-starting audio)

#21

Post by jeffreymcmanus » Mon, Sep 12, 2011, 11:43 AM UTC

tsotha wrote: post #11

jeffreymcmanus wrote: post #8

Earlier quoted context omitted.

The billions of dollars of investment is nothing compared to the positive effect that this will have on our society. The fact that this looks difficult from where we sit is not a good reason to not do the research. Many of the biggest discoveries in history looked impossible before they became ubiquitous.

The billions of dollars of investment is nothing compared to the positive effect that this will have on our society. You missed the point entirely. Billions of dollars in research, even if successful, will have no positive effect whatsoever if they don't lead to a commercially viable means of generating power. It's not enough to get to break even. The end result has to be cheaper than the alternatives. I'm not a big…

Basic research can have a net positive effect even if it does not result in a commercially viable product; that's how basic research works.

Anyway, if we go by straight cost/benefit, nearly all of the viable alternatives are polluting. And it's a fantasy to assume that we'll completely replace our energy consumption with renewables.

Re: Nuclear fusion 'will work' (auto-starting audio)

#22

Post by ugh » Mon, Sep 12, 2011, 3:32 PM UTC

pointyhat wrote: post #19

ugh wrote: post #9

Earlier quoted context omitted.

What are the practical implications of your pessimism?

I spend a lot of time with my family rather than chasing dead ends :)

I don’t understand. Are you a physicist? Why does being pessimistic about fusion give you more free time?

Re: Nuclear fusion 'will work' (auto-starting audio)

#23

Post by pointyhat » Mon, Sep 12, 2011, 6:21 PM UTC

ugh wrote: post #22

pointyhat wrote: post #19

Earlier quoted context omitted.

I spend a lot of time with my family rather than chasing dead ends :)

I don’t understand. Are you a physicist? Why does being pessimistic about fusion give you more free time?

Without going on too much of a philosophical tangent; not about fusion - about everything in general. It allows me to concentrate on now rather than in the future. Now is the only time that is certain. Now is the only time you get to enjoy your life before it's over or your children leave.

Re: Nuclear fusion 'will work' (auto-starting audio)

#24

Post by tsotha » Mon, Sep 12, 2011, 9:41 PM UTC

jeffreymcmanus wrote: post #21

tsotha wrote: post #11

Earlier quoted context omitted.

The billions of dollars of investment is nothing compared to the positive effect that this will have on our society. You missed the point entirely. Billions of dollars in research, even if successful, will have no positive effect whatsoever if they don't lead to a commercially viable means of generating power. It's not enough to get to break even. The end result has to be cheaper than the alternatives. I'm not a big…

Basic research can have a net positive effect even if it does not result in a commercially viable product; that's how basic research works. Anyway, if we go by straight cost/benefit, nearly all of the viable alternatives are polluting. And it's a fantasy to assume that we'll completely replace our energy consumption with renewables.

Basic research can have a net positive effect even if it does not result in a commercially viable product; that's how basic research works.

Projects like NIF and ITER aren't basic research, and in any case there are all sorts of competing interests when it comes to research - we'll get better bang for our basic research buck funding, say, the Web telescope or something like the LHC. The argument for ITER and NIF has always hinged on the promise that they'll be able to produce something useful within a few decades.

Anyway, if we go by straight cost/benefit, nearly all of the viable alternatives are polluting. And it's a fantasy to assume that we'll completely replace our energy consumption with renewables.

It's not a fantasy because we can't do it. It's a fantasy because we can't do it for a price we're willing to pay. But what fusion advocates are asking is we instead pay for something that's going to be even more expensive.

Re: Nuclear fusion 'will work' (auto-starting audio)

#25

Post by neutronicus » Mon, Sep 12, 2011, 11:09 PM UTC

queensnake wrote: post #17

neutronicus wrote: post #13

Earlier quoted context omitted.

The bulk of the energy release from hydrogen bombs is not generated by fusion. The general design of a hydrogen bomb is that a hydrogen "blanket" surrounds a fission "core". When the fission "core" goes supercritical, it releases enough energy to initiate fusion in the "blanket". What the "blanket" does at this point is exert pressure on the "core", which would be beginning to blow apart in a conventional nuclear dev…

How about that - I thought it was all about the binding energy curve : http://ec.europa.eu/research/energy/fi/fi_bs/images/fig2_147... where, as the diagram shows, fission comes up from the heavier elements (less energy difference) and fusion from the lighter (greatly more).

Per fusion event, you get about 14 MeV to the about 200 MeV you get per fission event. It's true that the binding energy per nucleon is higher, but there are many fewer nucleons.