Talk:Ballotechnics

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Sodium acetate

As described in the sodium acetate article, these heating devices work by using a supercooling solution, and releasing the resulting "latent heat of fusion" representing the energy change between the solid and liquid states.

A better example would be something like triboluminescence, where crushing a material produces light. --Christopher Thomas 19:43, 30 August 2006 (UTC)[reply]

I'm trying to see the distinction here. It is true that the mechanism is not quite as simple as I put into the page (deliberately), but the basic "you hit it, its gets warm" is still correct. No? Maury 21:23, 30 August 2006 (UTC)[reply]

No. It's "it crystalizes, it gets warm". The presence of a sharp edge or other suitable site, a speck of dust floating into it, or even a random organization after waiting long enough, will nucleate the crystalization. As far as I can tell from the article, "ballotechnics" refers to something where forced breaking of bonds releases energy. Completely different situation, and one that could probably stand being described in more detail itself (haven't sifted through the article's references yet). --Christopher Thomas 22:13, 30 August 2006 (UTC)[reply]

I made a simple edit to be far less specific about how they work. Actually it seemed to improve the readability in general. After all the article isn't about hand warmers, so getting too specific was likely a bad idea! Maury 13:46, 31 August 2006 (UTC)[reply]

Energy density

Regarding fuel energy density, it's important to note that this is per unit volume (with hydrogen being the worst offender; most of the mass of the Shuttle's liquid fuel is oxygen, but most of the space is taken up by liquid hydrogen). However, energy density per unit _mass_ has almost exactly the opposite situation, which is why it's important to note the distinction. My understanding was that liquid methane's per-volume storage density actually wasn't that much worse than other hydrocarbons, with the main problem being the fact that it has to be cryocooled to remain liquid. --Christopher Thomas 21:00, 30 August 2006 (UTC)[reply]

Change away! Maury 21:23, 30 August 2006 (UTC)[reply]

Done. --Christopher Thomas 22:17, 30 August 2006 (UTC)[reply]

Thanks!

Mike, thanks for expanding the cites, it really helps. Hey, is there software to make adding cites easier? I find them difficult to edit and all too easy to break. Maury 13:48, 31 August 2006 (UTC)[reply]

Definition problem

The definition of ballotechnics appears inaccurate. The references cited refer to ballotechnic as condensed phase materials that undergo shock-induced chemical reactions. Where shock-induced reactions refers to reactions induced by shock-waves that occur at with quick compression at GPa pressures (10,000's of atmosphere). That is far different from merely being mechanically worked, and is a different mechanism from sodium acetate. I suggest removing the discussion of hand warmers and changing the definition Salsb

What I find particularily interesting is the complete lack of information on the topic on the 'net. It seems so little referenced that it might be argued that it shouldn't even be an article on the wiki, and argument I wouldn't object to.

The only reason I wrote it in the first place is because of the confusion between ballotechnic mini-nukes, supported by Cohen who claims red mercury is a ballotechnic, and the IGE mini-nukes that are basically unrelated. This article formerly contained text about IGE (which was also in serious need of cleanup!) and had to be moved. I figured a short article here was better than a redirect to IGE, which was a completely different topic.

So, in effect, this article is a placeholder of sorts. Still, it's better than most stubs and not entirely without merit... Maury 18:44, 31 August 2006 (UTC)[reply]

Reference problem

There is a citation to a so-called "air force paper" which is seriously misleading. The "paper" is an abstract of a white paper which was submitted to the air force as part of their 2025 study project. So:

1) This wasn't produced by the air force. The name(s) of the author(s) are excluded but the top of the page clearly indicates that it is a submission from the public.

2) If you search through the study itself (go up two directories) is not referred to anywhere else; suggesting that it wasn't taken seriously.

3) if you look at the other abstracts submitted (go up one directory) you will see that this proposal was one of several that wasn't even completely assessed; also suggesting that it wasn't taken seriously

4) There are no actual references in the abstract to support the claim that "ballotechnic compounds appear to offer energy-density levels ten times greater than that of conventional pyrotechnic compounds." (Although such a reference shouldn't go in an abstract, this objection is to using it as a source for that statement since there is no information supporting said claim)

5) Usually anyone can submit such a proposal (the initial stage of which is called a white paper) in response to an agency announcement, and the agency is required to evalaute any such proposal (you can search through grants.gov for example for such announcement and read through the fine print).

So this citation is far from reliable, so should be removed along with the sentences it purports to support (unless another citation can be found). Salsb 14:03, 31 August 2006 (UTC)[reply]

Well done! Maury 18:34, 31 August 2006 (UTC)[reply]

"That said, it is worth noting that many of the references that can be found on the topic are in abstracts that trace back to US nuclear weapons labs, notably the Department of Energy[1] or Sandia National Laboratories[2]. "

The Department of Energy is not a nuclear weapons lab. Both of those references are in relation to people at Sandia. Not knowing whether this research was actually done in relation to weapons, it is very misleading to emphasize the lab aspect. Lots of research goes on at the DOE labs, even Sandia, Los Alamos, and Livermore, which has nothing to do with arms development. --Fastfission 20:49, 31 August 2006 (UTC)[reply]

Good points, I was annoyed enough about the other citation that I overlooked these.

The corresponding author on [2] seems to be in the Nanostructures & Advanced Materials Chemistry Department at Sandia.

The presenter on [1], which incidently is a conference report not a journal article, appears to be in the Exploratory Simulation Technologies department at Sandia, where he is a contact person for agent-based modeling and global climate modeling.

So neither of the researchers are involved in weapons research directly. Salsb 21:41, 31 August 2006 (UTC)[reply]