Wikipedia:Reference desk/Archives/Science/2018 February 6

= February 6 =

McKinley system of dealing with excrememnt
An earlier question about solids in/solids out in the context of the human digestive system led me to read our article Outhouse. It says "Alternatively, some parks mandate a "pack it in, pack it out" rule. Many reports document the use of containers for the removal of excrement, which must be packed in and packed out on Mount Everest. Also known as "expedition barrels" or "bog barrels", the cans are weighed to make sure that groups do not dump them along the way. "Toilet tents" are erected. This would seem to be an improvement over the prior practices, including the so-called "McKinley system"; there has been an increasing awareness that the mountain needs to be kept clean, for the health of the climbers at least." What is the "McKinley system"? DuncanHill (talk) 02:32, 6 February 2018 (UTC)
 * This I believe. -- Jayron 32 02:50, 6 February 2018 (UTC)

Regarding soundbars & loudspeakers
My question is divided into two, both are essentially technological.
 * What's the technological advantage of soundbars over loudspeakers, or vice versa ? (both technologies are still in use).
 * Now, focusing on soundbars - these are offered in a large range of prices, sometimes 3-4 times more. Beyond the brand aspect, what's the significant technological advantage of the more expensive over the (much) cheaper ? Comparison of their specifications doesn't show significant differences, and, yet, one can be a few times more expensive than another. There must be some prominent technological quality-difference justifying this, and I wonder what it is. בנצי (talk) 11:46, 6 February 2018 (UTC)
 * It's all just brand name hype and marketing.  Soundbars are sold in different shops from loudspeakers (UK anyway).  UK loudspeakers (as a separate purchase) are an obscure and somewhat high-end item, often bought after careful consideration, magazine reviews etc.  I can get a soundbar in a larger supermarket, from the TV section where they have a handful of models, picked by their marketing people, rather than representing the whole range potentially on offer to me. Then there are Bose, who have spent years hyping up the performance of their deeply averagely performing loudspeakers.
 * Physics is still much the same. Many aspects of loudspeaker design rely on size and mass. No speakers will work properly unless properly positioned. Yet our houses get smaller and smaller. Any clever hack to work around such a compromise always carries a premium. Soundbars don't deliver great sound (they can't, they're too narrow), yet they usually deliver better sound from the positioning they were at least designed for, than two speakers placed in the same place when they should have been twice that far apart. Yet we shop for sound equipment with our eyes, not our ears. So soundbars look like they ought to work better. Clearly they have more parts and are "more technical". You can achieve lots with a clever soundbar design (which will still need to be heavy and made from expensive drive units) but mostly these days it's about volume and bass volume, and ugly resonances just aren't a problem for sales. Andy Dingley (talk) 12:12, 6 February 2018 (UTC)
 * A soundbar will give you better sound than most TVs but, as Andy says, the cabinets are too small to give much bass so you need one with an additional large subwoofer that you hide behind the TV and just use the soundbar for the higher frequency speakers. The main problem with the one we had was that you had to use the soundbar remote to adjust the volume - so you needed to use one remote for most functions on the TV, a separate one to adjust the volume on the soundbar and another one for the cable TV tuner.  Richerman  (talk) 18:44, 6 February 2018 (UTC)
 * Socalled "Soundbar" could likewise, more fitting be called "stereo in one box" but then customers would notice more obvious this must be a oddly, technically reduced product - cheating you out of at least one box (compared to a stereo speaker set). A classical PR-stunt, selling you less, disguising it as a special deal for your advantage. --Kharon (talk) 19:29, 6 February 2018 (UTC)
 * Many soundbars come with four or even six boxes - nor do I see that as an advantage! It's very common for them to use a single subwoofer (they just can't deliver the bass otherwise), but as this is placed centrally, 'behind the couch' it loses all stereo imagery at low frequencies.  When soundbars are used for gaming they might use 5.1 surround sound to give the "It's behind you" quality which some games use, but the sound quality is often dreadful and nothing like a good music reproduction system. Andy Dingley (talk) 09:59, 7 February 2018 (UTC)

Question regarding Lake Tititcaca and former lakes in the same position with higher water levels
https://www.sciencedirect.com/science/article/pii/S0305440311001609 discusses that a characteristic type of agriculture in the Lake Titicaca region was dependent on a clay layer deposited by a "Lake Minchin" stage at elevations of 150 m above the present-day water surface. Thing is, Lake Minchin concerns a lake in the southern Altiplano and a highstand of Titicaca 15 m above its present-day level. On the other hand Mataro (ancient lake) - an even older paleolake - may have reached the exquisite elevation. So now I wonder if this agricultural factoid should be mentioned in the Minchin or the Mataro article if anywhere. Jo-Jo Eumerus (talk, contributions) 13:21, 6 February 2018 (UTC)
 * Lake Minchin was probably just one stage in the multistage lake appearance/disappearance process during the last glaciation. There are even doubts that it existed at all. So, it is not clear what you want to add to its article? Ruslik_ Zero 20:18, 6 February 2018 (UTC)
 * That it (or some other lake stage) did lay down the clay layer that allows for this kind of agriculture. Jo-Jo Eumerus (talk, contributions) 09:47, 7 February 2018 (UTC)