- The definition of "ignition" here means laser energy onto target vs. fusion power out. Current laser technology is not efficient enough at the high powers needed for ICF. It's still meaningful because in laser fusion the target physics is largely separated from the lasers so once the principles work an improved laser can be developed.
- The glass lasers used in NIF need to cool down for several hours between firings, whereas in a power plant the lasers need to fire at 10-15 Hz. High-power solid state lasers need development.
- The indirect drive scheme used in NIF is too inefficient to be used in a power plant. NIF uses a hohlraum to create a uniform implosion, but the conversion of laser energy to x-rays on the target is only a few percent.
I've been around NIF and it is an amazing machine. It's also designed (and funded) to study warm dense matter physics like equations of state at high density for nukes, not fusion. Use of NIF for fusion is a great side-benefit and hopefully they can get useful data from it.
The HiPER project to design a fusion reactor based on fast ignition has been though an initial concept design phase, but is now waiting further development. There is still a lot of research which needs to be done in target physics, lasers, and materials before ICF is ready to build an ITER-like machine
The physics behind the ITER tokamak on the other hand is quite well understood at this point. Sure there are outstanding issues which are still being worked on (ELMS, divertor detachment, RWM control spring to mind) but we're pretty confident it will work. The design of ITER started in 88, and before that the INTOR project in '78, but it has taken a long time for politicians actually put some serious resources behind it. Hopefully it won't take that long for ICF projects like HiPER to be taken seriously and funded at a level which will make them happen
if your taxes pay for research, then you get access to it, no exceptions.
What about classified research? e.g. weapons research? There need to be some exceptions, but they should be the exception, not the rule
Membership of assemblies was either by lot (similar to jury duty now), or consisted of those who wanted to be there (sort of like a parish council I guess). Public offices were often allocated by lottery from a pool of people who nominated themselves. From the wikipedia article:
Selection by lottery was the standard means as it was regarded as the more democratic: elections would favour those who were rich, noble, eloquent and well-known, while allotment spread the work of administration throughout the whole citizen body, engaging them in the crucial democratic experience of, to use Aristotle's words, "ruling and being ruled in turn" (Politics 1317b28–30). The allotment of an individual was based on citizenship rather than merit or any form of personal popularity which could be bought. Allotment therefore was seen as a means to prevent the corrupt purchase of votes and it gave citizens a unique form of political equality as all had an equal chance of obtaining government office.
Whilst there are good things about this system, I'm not 100% sure it's preferable to the current system. At the time it was criticised for allowing the many to tyrannize the few (mainly the rich).
Wholeheartedly agree that for trains and walking / cycling would be an excellent alternative. I own a car, but haven't driven it for over 6 months as I simply haven't needed to: walk to work (20 mins each way), walk or cycle to the shops and take the train for longer journeys.
Whilst driving can be enjoyable, there is nothing fun about motorway (freeway) driving. For long distances I'd much rather be in a train where I can walk around, stretch my legs, have a table to do some work on, even use Wifi on many of them. If I need a car where I'm going, hiring one at the other end is often pretty cheap.
Unfortunately, this is possible because I live close to the middle of town within walking distance of public transport. The dreams of living in bigger houses with individual transport far from the unwashed masses which the GP seems to object to, have lead to sprawling suburbs where it's almost impossible to walk anywhere. Either it's simply too far or because the planners assumed everyone would drive and made pavements (sidewalks) which end in 4 lane highways.
The options are then pretty limited: develop better, greener individual transport, or large-scale demolition and rebuilding in higher density areas which can be served more efficiently by public transport. Don't think the second one's going to be all that popular...
- Scaling up will almost certainly lead to additional loss mechanisms. Hotter plasmas have more free energy, and tend to have more violent instabilities which need to be controlled. Extrapolating too far from existing machines is a dangerous game, as ITER is finding in some ways.
- Bussard seems to claim that the thermalising Coulomb collision rate is small, and so Bremsstrahlung losses will be small. If you want high fusion rates then high density is needed, at which point I'm not sure I believe this one
- Neutron shielding the magnets and electrodes. If you have a power plant producing lots of neutrons then these do terrible things to conductors (turn them into insulators, structurally weaken, expand) and to superconductors (stop superconducting). In ITER and any tokamak power plant, all the magnets have to be behind lots of shielding blankets. How this could be done for electrodes I'm not sure. Not saying it's impossible, just that it needs to be shown.
In short, yes Polywells are an interesting design along with many other alternative fusion reactor designs (stellarators being most advanced, but also spheromaks, gas dynamic traps etc.). They're worth investigating, but as yet the only devices which have demonstrated long operation (minutes to hours in Tore-Supra) at fusion-relevant temperatures (10s of keV) and significant fusion power output are tokamaks. Hence why this remains the main direction of research.
Unfortunately we seem to be in a minority, and finding laptops with trackpoints is really hard. Impressed with the sturdiness of Lenovo laptops (still using an IBM-branded X41 from 2006), but you do pay through the nose for them...
In summary: Bring back Trackpoint (and get off my lawn)!