Misplaced Pages

Revision as of 04:10, 16 November 2005

Your vote on Metroblogging

You should really reconsider changing your vote on the metoblogging vote to delete, look at all the keeps now, it is clear that the site is important to many people 12.111.139.2 01:35, 31 August 2005 (UTC)

• You, sockpuppet, apparently are labouring under the impression that I am stupid. DV8 2XL 01:42, 31 August 2005 (UTC)

Forgot to sign your comment...

Just to let you know, you forgot to sign your vote at Misplaced Pages:Articles for deletion/Lord Dregg. Alr 23:25, 31 August 2005 (UTC)

• Thanks for the heads up DV8 2XL 23:33, 31 August 2005 (UTC)

Misplaced Pages:Articles for deletion/Fruit fetishism

Hi. I've substantially rewritten the fruit fetishism article (there really wasn't an "article" in the first place). Please check it out. -- BDAbramson 21:31, 1 September 2005 (UTC)

• OK, I'll change my vote - if only for the effort.

Thin-film deposition

Thanks for adding some more external links. Just so you know, the format for external links is a single bracket, with the description separated by a space rather than a pipe, like so:

Which displays like this:

Would you mind including a description of the links you included?

Cheers, Joel

TLAs

A proposal has been made at Misplaced Pages:Requested moves to move TLAs from AAA to DZZ and other related pages to Misplaced Pages namespace. Please visit Talk:TLAs from AAA to DZZ for the related discussion. -- Francs2000 | Talk File:Uk flag large.png 00:29, 16 September 2005 (UTC)

Many minds and quantum minds

I'll give it some thought, but I know next to nothing about either subject. I do know that many minds is largely Jeffrey Barrett's work (his book is in the library and I have checked it out). Barrett is a serious academic (that doesn't mean that I agree with anything he says) so the many minds article is definitely worth some effort. Barrett also has an article in the Stanford encyclopedia of philosophyThere is another article called consciousness causes collapse which may have been started (as a joke) by physicist Lubos Motl aka User:Lumidek. Quantum minds seems like Deepak Chopra stuff and of highly dubious worth. But again I'll look at it. --CSTAR 03:33, 14 October 2005 (UTC)

Many minds clearly precedes Barrett; it is apparently due to Albert and Loewer. See Barrett's article in the SEP See also this article by Deutsch .--CSTAR 03:48, 14 October 2005 (UTC)

Nuclear reprocessing

Thanks for writing Nuclear Reprocessing - truly a magnificent effort! You really did your research! Simesa 12:48, 10 October 2005 (UTC)

On a related subject hi from Cadmium, I have been editing as 86.2.102.238 and I have been adding to the same and related subjects.11:57, 6 November 2005 (UTC)

Quantum indeterminacy

Please see and comment on Talk:Quantum indeterminacy#Dispute status of this article. Thanks --CSTAR 18:13, 17 October 2005 (UTC)

Thanks, That's useful.--CSTAR 00:22, 19 October 2005 (UTC)

Re: Actor model, mathematical logic, and quantum physics

Please see the response on my talk page. --EMS | Talk 18:50, 18 October 2005 (UTC)

Reponse dans ma page discussion

Je t'ai repondu la bas.--CSTAR 03:42, 25 October 2005 (UTC)

deviate to excel? Malin.--CSTAR 04:23, 25 October 2005 (UTC)

science articles

Out of curiosity, which articles are you referring to here? — goethean ॐ 23:43, 2 November 2005 (UTC)

Cosmology is the last one that comes to mind DV8 2XL 23:47, 2 November 2005 (UTC)

nuclear fission

Thanks very much for the copyediting! Sorry to be metering this stuff out a little at a time... zowie 23:10, 8 November 2005 (UTC)

I think you're probably right that the nuclear fission article is stretching pretty long. I'm just about through with the section on reactor physics (which subsumes some of the other stuff, so it's not quite as bad as one might think) -- but it still looks to be a bit long. The main thing I'd like to address is that I wasn't able to find a clear description of the general physicsl "landscape" of fission devices anywhere else. For example, nuclear reactor contains a general description of reactor types but nothing on criticality, controllability, etc. The other bits of that physical description (such as delayed neutrons, reactor poisons, etc.) seem to be scattered all over, and it seems useful to collect them into one place.

I'm certainly not averse to having stuff pared down, particularly once everything is down on the page so it's obvious where it can be trimmed. Can we pick up this discussion in 24-48 hours? zowie 17:50, 11 November 2005 (UTC)

Gravitational radiation

Thanks! But you either need to hyphenate some of these, like in-spiral (conventional), or contract them, like inspiral (easier to type but not conventional).---CH (talk) 01:57, 10 November 2005 (UTC)

• Ya, it was a lick-and-a-promise spell-check, I needed to look up inspiral/in-spiral (and others) to see what the correct usage was. Now I know. DV8 2XL 02:10, 10 November 2005 (UTC)

A-bomb

If a compelling reason isn't given in a few days, I'll just turn it into a redirect. I don't think too many people need to get involved in this, it seems pretty straightforward. --Fastfission 23:18, 12 November 2005 (UTC)

Food irradiation

Thanks for the wonderful work on this article. When I tagged it for NPOV, I couldn't see how all the issues could possibly be fixed. Pakaran 07:29, 14 November 2005 (UTC)

Comments on your energy essay

First, let me say that your energy essay was well-thought-out and interesting reading. That having been said, there are a few points that you didn't mention that I found odd:

• Uranium as it comes out of the ground is about 0.7% U235. While this is the primary fuel used in fission reactors in North America, virtually all of the rest of the fuel (the U238) is usable if you're willing to breed it into Pu239, if I understand correctly. A typical light- or heavy-water reactor has bred on the order of 1% or so into plutonium before fission products start absorbing enough neutrons to stop the fuel rod from producing energy. Strip out the waste products and you have a usable fuel rod again (alternatively, you can enrich it by chemically separating out the plutonium; far easier than isotope separation). The catch is that plutonium fission requires control systems that react much more quickly than those used for U235 fission, but if I understand correctly these were still buildable without too much trouble. Reprocessing also tends to be both messy and a proliferation risk. I agree that thorium is cheaper if you're running a breeder, but I don't see why you wouldn't use both if you get both from the ore.
• The CANDU reactor uses heavy water so that you can use fuel bundles with only 0.7% U235 and still get more than one neutron produced per neutron emitted. US LWRs have to enrich uranium before they can do this. This, as opposed to use for breeding, was the main design goal of the CANDU reactor. They're still useful for breeding, of course.
• The "denatured" plutonium can still have its weapons-suitable isotopes extracted. India did that after buying CANDU reactors from us, if memory serves. I was amused when Chretien claimed there was no way our reactors could be used for weapons programs when talking about selling them to China. He almost certainly knew this wasn't strictly true (just more difficult). Such is politics.
• Fast-breeder reactors have high enough neutron economy that they can breed both U238 and thorium for fuel without worrying much about isotope content. The "integral fast breeder" project took advantage of this to use on-site electrorefining to separate out all of the lighter elements for disposal as short-lived waste, and recycled the heavy elements as fuel. You'll still get longer-lived isotopes in there, but it's nowhere near as nasty as with un-reprocessed spent fuel bundles from a non-breeder reactor.
• The big advantage to a hydrogen + CO2 = hydrocarbon system is that you can pipe the resulting hydrocarbons over the existing network from your synthesis plant. It's easiest to produce methane (burn CO2 in a hydrogen atmosphere), which is already a component of natural gas, and so can be distributed without any problems. Methanol might require changing the lining of distribution pipes and tanker trucks, but you have nowhere near the hassles you have with hydrogen, and methanol is already distributed on a large scale as an industrial chemical (and as windshield wiper fluid, up here), so the problems are well-understood. Dimethyl ether is a bit nastier, harder to synthesize, and not that much easier to handle than methanol, so I don't really see the attraction to it, but presumably it has some useful properties or it wouldn't have been studied. Vehicles that burn natural gas are produced commercially already, so a switchover would seem politically feasible. There are enough methane hydrate deposits offshore that we'll have cheap sources for a while even if local reserves get depleted.
• The other advantage is that you can adopt reforming fuel cells to process methane or methanol directly if you have an application where it would be useful to do so, but aren't _forced_ to (you can burn methane in a turbine and methanol in either a turbine or a properly tweaked internal combustion engine).
• There are two big disadvantages to CO2 + hydrogen = hydrocarbon system. Part is that you waste some of your hydrogen forming water (from the oxygen you're stripping or partly stripping from the CO2). This represents wasted power (you have to electrolyze water to get your hydrogen). The bigger problem, however, is isolating CO2. CO2 concentrations in the atmosphere are very, very low. Ramming enough atmosphere through an effusion membrane or bubbling it through water or what-have-you takes a very considerable amount of power. Trying to freeze CO2 out of air is even worse (you have to move the air, _and_ you can't get better than Carnot efficiency dropping the temperature). Back of the envelope calculations I did came up with numbers that we might eventually tolerate, but not any time soon: about 5 times higher than the current price of gasoline.
• While I don't think that biomass will ever compete efficiency-wise with direct synthesis for producing methane, I think it's not quite as impractical as you're painting it. A realistic system would be based on algae ponds. These can even be built in open ocean, though I doubt anyone would bother.
• While thick-film solar cells are enough of a pain to manufacture that I doubt they'll ever be useful for system-wide power generation, thin-film cells are much, much better for that, and are available over the counter right now. The main drawback to photovoltaics is efficiency. The kind you're likely to be able to mass-produce cheaply are only about 5% efficient, so I'm not convinced that system costs will be lower than for my favourite solar implementation - polished aluminum concentrator mirrors shining on a central heat plant. You have various tradeoffs available between efficiency vs. how often you want to have to realign the mirror arrays for a centralized boiler, vs. using trough-style concentrators and heating a working fluid by a smaller amount in pipes. If nuclear and coal are deemed unacceptable in the US, I think solar is what will take over.

ObDisclaimer that I'd want to sanity-check most of the above before putting it in a WikiPedia article as Verified Truth :). Your essay was still very interesting reading. --Christopher Thomas 04:54, 15 November 2005 (UTC)

Notice of Request for Arbitration

As it does not appear that an amicable solution to the contention over A-bomb will appear, I've filed for a Request for Arbitration. Tmayes1999, Christopher Thomas, Fastfission, and DV8 2XL are named as involved parties. --Christopher Thomas 04:10, 16 November 2005 (UTC)