Miscellany

[stoutfellow]

1. It looks like we've got Murphy's skin condition licked. This afternoon the vet told me he needed to finish the course of antibiotics and vitamins, but I wouldn't have to bring him in again. He does look much better, and the bare spots aren't fever-warm any more.

2. I finally got Season 4.3 of Farscape, plus The Peacekeeper Wars. They weren't available last September, when I bought the rest of the DVDs; now I have the complete set. (And just in time; I'm about to start in on watching Season 4.2.)

3. On a related note, a bit of trivia: in the episode "Natural Election", the crew of Moya elect a captain. The voters are John, D'Argo, Rygel, Pilot, Aeryn, Chiana, Sikozu, and Noranti. There is one vote each for Scorpius (certainly cast by Sikozu), Rygel (presumably by Rygel), The Great Beyond or something like that (Noranti), and Aeryn, and four votes for D'Argo. I'm wondering who voted for Aeryn. Not Chiana - she's an almost certain vote for D'Argo. Probably not Crichton, given their estrangement at that point. I doubt that Aeryn would vote for herself, either. Pilot seems most likely to me - he's had a special bond with Aeryn since "DNA Mad Scientist". It's conceivable that D'Argo would be humble enough not to vote for himself, though. Any other Farscapers care to comment?

4. I just finished reading Vernor Vinge's Tatja Grimm's World, and something's bothering me. Among the key plot points are that a) the (Earthlike) planet in question is very low in metals and b) there is a high mountain range, one of whose peaks is high enough that the partial pressure of oxygen near the top is 0.7 PSI. Now, I'm not that knowledgeable about geography/geology, but that combination doesn't sound right to me - tectonics on Earth are driven by radioactive decay in the mantle, aren't they? The planet is part of a double-planet system, though. Could tidal effects substitute? Anybody know more about it than I do?

Comments

[pompe.livejournal.com]

4. When you mean Earthlike, would you be able to specify?

Otherwise, metal-poor is perhaps a problematic issue. Is the planet metal poor or just the crust of the planet? I'd argue that a terrestrial planet with ongoing tectonics probably has a lot of metals and that would mean some tend to end up in the crust.

About 4/5 of Earth's internal heat is radioactive decay, about 1/5 is "Leftover Heat". Tidal effects could generate heat, but I'd guess a double planet system realistically would be tidally locked to each other and then you need the tides to change because such a stable system is poor at generating tides! Perhaps solar tidal effects in combination with a locked system could generate enough tidal activity.

[stoutfellow.livejournal.com]

When you mean Earthlike, would you be able to specify?

The planet is Earthlike enough to support a population of about a billion, at tech levels ranging from hunter-gatherer to early 19th century (the latter modulo techs that absolutely require large amounts of metal). At sea level, the partial pressure of oxygen is about 3.0 PSI; the atmospheric pressure at the peak is about 1/5 that at sea level. The planet's primary is itself low-metallicity compared to its neighbors.

There's no explicit mention of tide-locking, but there are hints that that is the case:

One of the first steps would be to build an observatory in this part of the world, where Seraph [the twin planet] could be observed with a minimum of atmospheric distortion.

There's also a reference to "eclipse time", during which time Seraph either eclipses the sun or is itself eclipsed every twenty hours. (The planetary day is 40 hours; the year is 220 days long. The locals have no "month" concept, which also fits the possibility of tide-locking.)

[pompe.livejournal.com]

Low-metallicity really doesn't mean "metals", it means anything heavier than helium, IIRC. So it isn't necessarily that that there's less metal on a world, it is perhaps more like less solids to build worlds of. Similarly less metals might mean smaller metal core, which may or may not influence the crust. It is a problem with the classic metal-poor SF worlds, the authors may or may not rationalize what metal-poor really means.

However, from a purely stable view I'm not sure if the situation above would work -I wrote about moons a while back. If the planet is locked at a forty hour orbit and solar tides act to despin the double planet to such a degree it actually generates a really serious amount of tectonic heating I'd guess the planets may well be doomed. The energy comes from a falling moon, in a sense. How big is the second planet? Big enough to also be Earth-like?

If I'd do a metal-poor world in the "no industrial revolution"-sense I'd choose a situation with more dead tectonics. Huge highlands and mesas, erosional features (and thus less oxygen with dying cycles). So the deposits are largely covered by a lot of sediment (or ice caps). There's no serious mining not because of a lack of metals, but because of a lack of ore to easily dig up.

[stoutfellow.livejournal.com]

Low-metallicity really doesn't mean "metals", it means anything heavier than helium, IIRC.

Sorry, I should have been clearer: the local astronomers had discovered via spectroscopy that the neighboring stars actually had much more metal - iron and copper were specifically mentioned - than their primary.

How big is the second planet? Big enough to also be Earth-like?

Yes; it appears to have life.

[pompe.livejournal.com]

Hmm. That's another classic which might be hard to explain by normal planet-forming scenarios.

I'd say in this case I would find it slightly hard to justify sufficiently strong tectonics - well, if they're Earth-like tectonics, they could be hot spot tectonics or maybe blob tectonics.

I presume the eclipse time only makes sense in the part of the world actually facing the other planet. Does the planet have seasons?

[stoutfellow.livejournal.com]

I don't see any explicit mention of seasons, no. (The locals do divide their year into quarters, for whatever that's worth.) The existence of eclipse time seems to suggest that the orbit of the twin planets about each other is at an angle to their orbit about the primary. If they're tidelocked, doesn't that imply that their axes are tilted relative to the ecliptic?

[pompe.livejournal.com]

Hmm. If there are eclipses every twenty hours of the local year, can the twin-planet orbit be much inclined to the planet-solar orbit?

[stoutfellow.livejournal.com]

Oh, I think we've crossed wires. Here's the relevant passage: "They were well into the eclipse season; once every twenty hours, Seraph blocked the sun or was itself eclipsed." I read that as saying that this pattern of eclipses occurs at certain times of year, not at all times.

[pompe.livejournal.com]

Yes, that makes much more sense. It is like Pluto and Charon. Still, the eclipse season would only make sense on part of the world.

[bright-lilim.livejournal.com]

"Any other Farscapers care to comment?"

I think that Pilot voted for Aeryn. However, that does mean that D'Argo would vote for himself, which is a bit too egoistic for him. OTOH, maybe he just went through all the other candidates and decided that he didn't want to obey any of *them*.

[stoutfellow.livejournal.com]

Looked at that way, I can see D'Argo voting for himself. Under other circumstances, he might vote for Aeryn, but her bringing Scorpius on board and protecting him would have damaged D'Argo's trust in her. Yeah, it has to have been Pilot.

[bright-lilim.livejournal.com]

I can just see him going: "Not him, certainly not him, she's not a captain material, if *he* wins, I'll throw him out of the airlock! ... or myself, if I have to..." :)

To bad they didn't film that. :)

[stoutfellow.livejournal.com]

Yeah, that could have been funny. It might have disrupted the suspense (such as it was) over the selection of the new captain, though.

[filkferengi]

Woof!

[carbonelle.livejournal.com]

Glad to read that the Murph is doing better. We've been struggling with a similar problem with our Kasey-gal. I can't really complain: any dog whose survived a throat-and-larynx-and-fargin'-spinal-cord tumor is doing just great having nothing more than skin condition, but still... It's a pain, and the poor dog...

So I'm glad it's working out. Have you been using the fish-oil supplements? We buy ours from our local vet (they cost the earth, but, well, that's a long story for another day) but you can get them fairly cheaply from Doctors Foster and Smith (http://www.drsfostersmith.com/?ref=3442&subref=AJ&cm_mmc=PPC-_-Google-_-DFS%20Keywords-_-foster%20and%20smith&s_kwcid=foster%20and%20smith|914620581).

I'm slowly working my way through the library system's copies of Farscape too--we should compare notes if we ever get to the same spot!

[stoutfellow.livejournal.com]

Have you been using the fish-oil supplements?

Yeah, the vet gave me a bottle of DermCaps, and Murphy's fur seems to be coming back in pretty well.

[stoutfellow.livejournal.com]

How far along are you in "Farscape"? (I've actually seen all of the episodes, but until now I hadn't seen them in order, which makes a big difference.)

[carbonelle.livejournal.com]

I've just finished season one.

When it first came out the season finale was the first episode I saw. I like it enough to try to catch more, but the show was painfully hard to keep track of (not as bad as Firefly, but bad enough)

I'm really enjoying it--the show was lightyears ahead of its time.

[stoutfellow.livejournal.com]

I find the episodes vary wildly in quality, but the overall arcs, and many of the individual episodes, are excellent.

If you liked the season one finale, wait'll you see the season two finale...

[carbonelle.livejournal.com]

It's on my hold list!