Wikipedia:Reference desk/Archives/Science/2018 September 24

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September 24

What's happened with the PHYTOME project?

Have there been any new processed meat products with phytochemicals sold in the marketplace ever since the project was finished in 2016? — Preceding unsigned comment added by 184.67.108.46 (talk) 10:45, 24 September 2018 (UTC)

filtering salt out of seawater

"The teenager only had a few days worth of supplies and survived by catching fish, burning wood from his hut to cook them, and sipping seawater through his clothes to minimize his salt intake."[1] Can one filter out salt by sipping seawater through the textile of one's clothes? Bus stop (talk) 14:12, 24 September 2018 (UTC)

No, that will not work - but it doesn't mean he didn't try it (or that the news report was inaccurate).

From a scientific point of view, salt water is a chemical solution - the salt has dissolved into the water and is present as individual ions of sodium and chloride. Many textbooks define a solution as a mixture that cannot be separated by filtration. Cloth isn't even a good filter - so it's not going to have any effect at removing the salt - not even in ideal laboratory conditions.

From a practical, survival point of view: this isn't a standard procedure either. Almost all sources agree: in a survival situation at sea, it's better to drink nothing than to try to drink seawater. For reference, I pulled out the Army Survival Manual, which you can purchase online in reprint. They make it pretty clear: do not drink seawater, unless you have a real desalination kit. "By drinking seawater, you deplete your body's water supply, which can cause death." Nimur (talk) 14:23, 24 September 2018 (UTC)

It's pretty clear this is the way it has to work since seawater has more salt than the body's solutes. (almost 4 times as much in fact) Sagittarian Milky Way (talk) 14:56, 24 September 2018 (UTC)

What about using a funnel, and covering it with a piece of paper, into a bottle. Then constantly pouring the water from a bottle back to the funnel. Well, the easy answer to check is if you see salt piling up in the paper funnel, then you're getting progress. 67.175.224.138 (talk) 02:56, 25 September 2018 (UTC).

I think I read something about getting the fluid from the eyes and spine of fish but no other fluid from them and not eating and that would keep you going for a while. Rather desperate but needs must I guess. Dmcq (talk) 14:37, 24 September 2018 (UTC)

They may be incorrectly describing a solar still. --47.146.63.87 (talk) 21:20, 24 September 2018 (UTC)

In the original language of the article, it says that he squeezed sea spray from his clothes and drank that. He didn't filter the water through his clothing. I'm not claiming that is better. It is just not the same thing. 216.59.42.36 (talk) 18:11, 26 September 2018 (UTC)

Baker Dam

Which Baker Dam, upper of lower, uses Pelton turbines?Rossroderick (talk) 15:02, 24 September 2018 (UTC)

I don't think you need to repeat the same question every other day: You can simply continue an opened thread. From all the posts in the last one ( https://en.wikipedia.org/wiki/Wikipedia:Reference_desk/Science#Baker_Dam_turbines,_continued_dialog ) I got the impression that there are no sources stating what kind of turbines are mounted in the Baker Dams, so there is no answer to your question, even if you ask it a fourth and a fifth time. 194.174.73.80 (talk) 13:58, 25 September 2018 (UTC) Marco Pagliero Berlin.

@Rossroderick: If you're in the area, you can try Free tours of Baker River Hydroelectric Project, or try "Contact us. We welcome your questions and comments!" —107.15.157.44 (talk) 15:58, 25 September 2018 (UTC)

I've been reading this discussion for a few days. The link Andy Dingly gave after your first question clearly tells (if anybody had taken the effort of actually reading it...) that the new Lower Baker Unit 4 has a Francis turbine. Lower Baker 1 and 2 no longer exist. It doesn't tell anything about Lower Baker 3, but at the same head and higher flow than Lower Baker 4, it's probably a Francis turbine too. Pelton wheels are more common for high head, low flow. No source has been found for Upper Baker. It has slightly higher head and lower flow than Lower Baker, so it could be either type of turbine.

BTW, the fish-friendliness of Lower Baker 4 is all about fish-friendly management of downstream waterlevel. PiusImpavidus (talk) 17:11, 25 September 2018 (UTC)

Where in the deepest bedrock in the world?

Where is the strongest? (lb/in² before a load slowly placed directly on a leveled part of the top of the bedrock damages it) Sagittarian Milky Way (talk) 15:54, 24 September 2018 (UTC)

I'm not clear on what you're asking - bedrock goes from the base of superficial deposits down 10s of km. The strongest part of the crust is at the brittle–ductile transition zone, beneath which higher temperatures promote crystalplasticity. Mikenorton (talk) 17:18, 24 September 2018 (UTC)

I was asking about the top of the bedrock. Sagittarian Milky Way (talk) 17:31, 24 September 2018 (UTC)

Do you mean "How far down is the deepest from the surface one has to go to reach bedrock?" --Jayron32 17:41, 24 September 2018 (UTC)

If you are this paper seems to have all of the data you need. And then some. --Jayron32 17:45, 24 September 2018 (UTC)

That paper implies that there is a place in the US where the rockhead (that's what the top of bedrock is called) is more than 3 km below the surface. That seems a little high in my view, although I can't see the data that was used to give that value, presumably a borehole record. There are plenty of places globally that have hundreds of metres of superficial deposits however, especially in areas that were once close to the front of ice sheets (during the last glacial maximum), where the mass of sediment coming from the ice sheet infilled any existing topography - valleys, lakes etc. Mikenorton (talk) 19:24, 24 September 2018 (UTC)

Actually, if you read the paper, they actually made your exact point years before you thought to write it. --Jayron32 03:44, 25 September 2018 (UTC)

Three km deep sediments are not rare, for example the Po river delta in Italy and the Brandenburg region in Germany are said to lie on three km of sand. But you don't need a three km depression at the beginning: the weight of few hundred metres of sediments can sometime cause the crust to sink into the mantel, so as to give place for even more sediment to accumulate and so on. 194.174.73.80 (talk) 14:50, 25 September 2018 (UTC) Marco Pagliero Berlin

Is it possible for sediments to break through the crust when it was thinner or in the far future if they accumulate enough? Maybe if the sediments continental drift to a place where 4+km of ice form on top? Sagittarian Milky Way (talk) 15:37, 25 September 2018 (UTC)

Sediments (more properly sedimentary rock) can be pushed under the crust at subduction zones. But no, there's nothing to "break through". It's not like the crust is sitting over nothing, there's dense, plastic solid mantle underneath. --Jayron32 16:04, 25 September 2018 (UTC)

As Jayron says, we're dealing with sedimentary rock, not unconsolidated sediment, as once we have a thick enough accumulation (and therefore high enough temperature and pressure) the process of lithification starts. That's why I balked at 3 km to bedrock, because the bottom of such a sequence would have become lithified and therefore would form part of the bedrock itself (and of course part of the crust). There are a some places where unconsolidated sediments were deposited directly onto exhumed (if somewhat altered) mantle, non-volcanic passive margins, but that's because during continental break-up the crust has been thinned away to nothing before the mantle part of the lithosphere has given way - this has been proved by the Ocean Drilling Program (e.g. hole 637). Mikenorton (talk) 18:38, 25 September 2018 (UTC)