Wikipedia:Reference desk/Archives/Science/2017 August 16

= August 16 =

Can foil dissolve in stomach?
Could a piece of aluminium foil be expected to be dissolved in the stomach and poison a person? I'm not seeking medical advice but I do figure that with a lot of chocolate wrapped in foil around the world, some people must end up eating a bit here and there and it used to be thought that aluminium absorption was correlated with Alzheimer's so maybe chocolate shouldn't be wrapped in foil. --145.255.246.8 (talk) 06:32, 16 August 2017 (UTC)
 * See: Aluminium poisoning. --47.138.161.183 (talk) 08:42, 16 August 2017 (UTC)
 * That article is amusing. It says that doses of 40 mg/kg per day may cause problems. For an average size person that's a lump of aluminium about the size of a sugarcube. Every day. My fillings cringe. Greglocock (talk) 11:11, 16 August 2017 (UTC)
 * People do consume aluminum. It used to be that most consumption came from using aluminum cookware and utensils. Now, most consumption comes from using aluminum cans. A single can of drink will contain less than 1 mg of aluminum, so while it is a primary source of aluminum, it is still considered safe. 209.149.113.5 (talk) 12:38, 16 August 2017 (UTC)
 * Relevant is the dose makes the poison. -- Jayron 32 13:53, 16 August 2017 (UTC)
 * Some antacids also contain aluminium. — Paleo  Neonate  – 15:02, 16 August 2017 (UTC)


 * Can foil dissolve in stomach?
 * answer in


 * aluminium: exposed to oxydation, aluminium forms a corrosion-resistant layer of aluminium oxide
 * aluminium oxide dissolves in alkaline solution of water (as stated in Aluminium), but not in water and acid. Digestion occurs in acidic solution, so it wouldn't dissolve.
 * So the answer is: no
 * So even if you eat the whole foil around your chocolate (in which case you roughly get the sugarcube-size lump hinted at by Greglocock above), you will just defecate it away.
 * Relevant authorities already considered the impact of aluminium foil around chocolate and other food, and concluded it isn't worth worrying, even though in the quite paranoid mood of the day nothing is safe from tin foil hat bearers smear.
 * Gem fr (talk) 12:47, 17 August 2017 (UTC)
 * Actually, aluminum oxide does dissolve in acid, see Aluminium_oxide.--Wikimedes (talk) 19:24, 20 August 2017 (UTC)

gluconeogenesis
Does during ketosis does gluconeogenesis using protein replenish glycogen stores in the liver? Would eating too much protein cause gluconeogenesis to produce so much glucose that ketosis comes to an end? FatWater2 (talk) 10:30, 16 August 2017 (UTC)
 * Not sure, but it seems unlikely, as the same fasting conditions that produce gluconeogenesis also induce the body to undergo glycogenolysis, i.e. the body is breaking down glycogen faster than it can produce it. Remember, even under extreme ketosis, one's blood glucose levels never drop to zero; glucose has other roles besides just producing energy, and a blood glucose level of strictly zero sounds a lot like dead to me.  Still, I can't find any definitive answer, other than reading the articles I linked, which hints that is not the case.  Someone else may be able to direct you to better reading materials on the subject.  -- Jayron 32 10:50, 16 August 2017 (UTC)
 * Found something. According to this:  no, you cannot generate enough glucose through gluconeogenesis to override ketosis.  In short, that article states that it is a "demand-driven rather than supply-driven process", in other words the body only uses gluconeogenesis to meet its bare minimum needs for glucose, and dumping extra protein into your system does not cause it to ramp up.  -- Jayron 32 10:54, 16 August 2017 (UTC)
 * To elaborate: note that "ketosis" just means your body is burning ketone bodies for energy, which it generally doesn't do if you're in a well-fed state. If you're in ketosis (assuming there's no medical abnormality), your blood insulin is low and glucagon is high. Low insulin tells cells to reduce glucose uptake from the blood. Glucagon tells the liver to dump glucose into the blood, which it gets from breaking down glycogen and gluconeogenesis. But then as blood glucose rises, glucagon levels go down and insulin levels go up, which then downregulates glycogenolysis and gluconeogenesis in the liver. It's a negative feedback loop; the liver (again, normally) will never produce so much glucose that insulin and glucagon levels return to the "well-fed" state and the liver starts storing glucose again. If you eat lots of protein, excess amino acids are burned for energy, or converted into fat, or glycogen in the muscles, and stored. (Gosh, some of those words are a mouthful!) --47.138.161.183 (talk) 02:53, 17 August 2017 (UTC)

Do computer weather models take eclipse insolation drop into account?
Variation in sunlight brightness caused by Earth's elliptical orbit? The solar cycle? Sagittarian Milky Way (talk) 23:34, 16 August 2017 (UTC)


 * In my experience, the typical answers are no, yes, and sometimes (if the same model is intended for both weather forecasting and long-term climate studies, as some more recent models are). Dragons flight (talk) 07:40, 17 August 2017 (UTC)


 * When an eclipse occurs, people don't care for the weather they would had if it hadn't occurred, they care for the real wether they experience, don't they? So it would be quite foolish for weather forecasters to not take into account an eclipse, which is in itself a meteorological event and a sure headline, with significant local impact on temperature and other weather variables.
 * Whatever the phenomenon, when you make short time scale prediction, you don't have to take directly into account long period variable, as they are already embed in your base data. That is, today's weather data that are fed to numerical weather prediction models to forecast weather for the next few days obviously embed current (august) sunlight brightness in current solar cycle.
 * So Variation in sunlight brightness caused by Earth's elliptical orbit may be of use (or not), but, for my 2 cent, i bet season (and simply date, in our efficiently tuned with season calendar system)) is far more useful, as it correlates with sunlight brightness, not just the one caused by Earth's elliptical orbit.
 * Solar cycle may have Atmospheric effects, but their variations are not fast enough for weather prediction: current weather, under current solar cycle state, is enough data.
 * Gem fr (talk) 13:47, 17 August 2017 (UTC)


 * Regarding eclipse effects, they are pretty short-term, of course. This article may be of interest. --69.159.60.147 (talk) 22:53, 17 August 2017 (UTC)