Science desk
< May 16	<< Apr \| May \| Jun >>	May 18 >

Welcome to the Wikipedia Science Reference Desk Archives
The page you are currently viewing is a transcluded archive page. While you can leave answers for any questions shown below, please ask new questions on one of the current reference desk pages.

May 17[edit]

What would cause these 'dark area' blemishes on an LCD monitor?[edit]

See this photo: https://ibb.co/mz8vQh0

This is my Asus Designo MX25AQ main monitor, I've had it for a little over four years and two months now. Since about a year ago, it started developing this issue where a "wavy" area of darkness appears near the left and right edges of the screen. It looks as if there's liquid in the screen or if something's "delaminating" inside. It would usually happen when it's cold, and would go away / "fade away" as it warmed up (usually taking a few minutes). However, over the last few months, it's been getting worse and worse. Nowadays, sometimes it's visible on certain shades of colours even when the monitor is fully warmed up. It is especially noticeable when it cools down in real life (e.g. it's becoming dawn and the brightness has been decreased).

The "grey uniformity" of the monitor has been degrading a bit as well, I swear.

I know I likely won't be able to fix an issue like this with the LCD panel. But my question is, what would possibly cause these issues? Could it develop into a stage where my LCD becomes completely / severely broken?

Note that I'm posting this to RD/S and not RD/C because I strongly believe this issue has something to do with materials degradation in the LCD and not some issue with the computer or cable, so I figured this is a better place for that.

Apologies for the non-free external image site upload, but if everything you see in the photo is not copyrighted then I will upload it to Commons. — AP 499D25 (talk) 05:03, 17 May 2024 (UTC)[reply]

I Googled around, and it could be moisture infiltrating around the edges. The fact that it clears when hot is suggestive of that. There was a suggestion that if the monitor is near a kitchen, these stains could include cooking fumes. Another possibility (and conceivably related) is damage from pulling the protective plastic sheet off, the one that came when the monitor was newly purchased. This has to be done extremely carefully. Yet another worry is cleaning with rubbing alcohol, the internet says this is a bad idea. Abductive (reasoning) 06:11, 17 May 2024 (UTC)[reply]

Rubbing alcohol as sold can consist for up to 50% of water. --Lambiam 09:16, 18 May 2024 (UTC)[reply]

That sounds plausible! Thinking about it, more than a year ago I did clean my monitor using a wet microfibre cloth (a small, thin one for phones), and that seems to be the timepoint it all started. Worth pointing out that this monitor is in a bedroom, so it's not near moisture or oil vapour sources, and it has never been used in such an environment. When I got it new, there wasn't actually a protective sticky film on the front, just a styrofoam wrap. When I slid that wrap off, I got a nice big static shock when I touched the monitor bezel, but that didn't seem to do any immediate damage – this monitor was fine for the first 2.5 years or so that I used it.

Another interesting fact about this monitor is that although I bought it in Mar 2020, according to the info label, it has an manufacture date of Sep 2015, so that means it sat in a warehouse for 4.5 years before I bought it I guess.

Aside from this annoying and distracting issue, this monitor is the best quality display I've ever had (QHD resolution and 100% sRGB accuracy), so it'd be such a shame if it's actually dying on me. — AP 499D25 (talk) 08:06, 17 May 2024 (UTC)[reply]

Is there any scientific truth to the meme that Vegetable oil/Seed oil is toxic to the human body?[edit]

There are plenty of memes that seed oil causes diabetes and heart attacks but I failed to find any wikipedia articles that argues their case. Is there any scientific truth to the meme that Vegetable oil/Seed oil is toxic/harmful to the human body?

Another question is that if the meme of harmful seed oil is unscientific then why isn't this meme documented in the List_of_conspiracy_theories wiki page? 2001:8003:429D:4100:A593:8A5B:182E:5551 (talk) 15:55, 17 May 2024 (UTC)[reply]

Any kind of fats or oils in excess can cause heart disease, but there is no truth to the claim that vegetable oil is more toxic than animal fats (in fact, it's actually healthier) or that its consumption in moderation causes any health problems. 2601:646:8082:BA0:9480:50AE:ABF3:5E17 (talk) 23:30, 17 May 2024 (UTC)[reply]

Yes, there is truth to it. Our nutrition articles could do with some updating and balance. It is a prime example of Paracelsus's The dose makes the poison, for both the omega 6 LA and omega 3 ALA are essential nutrients for humans. The basic issue is consumption of a high quantity of omega-6 fatty acids from modern seed oils (which have only been consumed for a century or so) and other sources, including indirectly through animal feed and the (relative) paucity of omega-3 fatty acids in the modern human diet. [Excessive omega-3 over omega-6 has been found only in Greenlandic Inuit traditional communities.] Probably the best book to start with is Anthony John Hulbert's recent Omega Balance: Nutritional Power for a Happier, Healthier Life- Johns Hopkins (2022). By omega balance, he means the percentage of omega 3's in the sum of omega 3's and 6's. He says:

Although there is no advice about separate consumption of omega-3 and omega-6 fats in these national dietary guidelines, this is not the case with the premier scientific society concerning lipid research. In 2004, ISSFAL (International Society for the Study of Fatty Acids and Lipids) issued a series of recommendations for dietary intake of the essential fats by healthy adults. They made no comment about consumption of the nonessential saturated and monounsaturated fats but instead proposed that adequate intake of 18:2ω-6 [ Linoleic acid (LA) ] is 2 percent of energy, and a healthy intake of 18:3ω-3 [ α-linolenic acid (ALA) ] is 0.7 percent of energy as well as recommending a minimum intake of 500mg/d of 20:5ω-3 [ eicosapentaenoic acid (EPA)] and 22:6ω-6 [sic, should be 22:6ω-3 docosahexaenoic acid (DHA) as in the source [1]]. These ISSFAL recommendations for daily intake correspond to a diet omega balance of about 30 percent. The recommended intakes contrast markedly with the average actual daily intakes by the US population (from a 1999–2000 survey), which correspond to a diet omega balance of 9 percent. Similarly, a dietary survey of the Australian population revealed the average daily intake in 1995 corresponded to a diet omega balance of 11 percent. Both the United States and Australia (and likely many other developed high-income countries) have omega-6 intakes much higher and omega-3 intakes lower than the recommended levels.

Hulbert and other sources provide evidence that the omega imbalance can have deleterious effects not only in various chronic diseases, but also that the excess of inflammatory omega-6's can worsen outcomes of Covid, where many deaths appear to come from an excessive inflammatory response.John Z (talk)

μ-Oxidodihydrogen, a chemical compound found in industrially processed canned soup, is also known to be toxic to the human body. Why is no one talking about this? --Lambiam 09:10, 18 May 2024 (UTC)[reply]

In very large excess, such as Olympic sized swimming pools, you would find it extremely difficult to swim in oil. Graeme Bartlett (talk) 12:37, 20 May 2024 (UTC)[reply]

It might be even more difficult in a bathtub. --Lambiam 19:31, 20 May 2024 (UTC)[reply]

A wry comparison to the dangers of water is appropriate to much or most discussion of nutrition. Which proceeds by demonizing food X and then along with declaring it causes disease Y, X is declared to be a novelty even though it was consumed by all or much of humanity for tens of millennia at least, or is even essential to life. Historical absurdity is absurdly accepted. But it isn't relevant here because nobody considers modern seed oils to be anything but essentially new foods, never existing or consumed in such bulk before by humans or by any animal. And there aren't many such candidates for widespread dietary changes that could be implicated in global rises of chronic diseases.

Another source, which may conceal some such wryness, is Harumi Okuyama, Yuko Ichikawa, Yueji Sun, Tomohito Hamazaki, William Edward Mitchell Lands- Prevention of Coronary Heart Disease: From the Cholesterol Hypothesis to omega 6 omega 3 Balance- Karger (2006). They note that "Dietary advice was revealed to be the most serious risk factor for CHD in Japan." "We suggest that increased intake of LA [a consequence of that advice as it raised seed oil consumption] may be a major cause for the observed increase in CHD incidence in the group with dietary advice. Higher intakes of LA accompanied higher rates of CHD ( fig. 9–11 ; tables 4 , 5 ), whereas decreasing LA intake was effective for the secondary prevention of CHD events". In any case, there is a genuine, active scientific controversy here, not a conspiracy theory. Those who see omega imbalance as a real problem - and therefore seed oils, which uncontroversially are its ultimate source- may be the majority of specialist lipidologists, e.g. William E. M. Lands or Artemis Simopoulos, cofounder of ISSFAL.John Z (talk) 04:20, 21 May 2024 (UTC)[reply]

Butterfly size[edit]

Do butterflies (especially nymphalids and/or swallowtails) become significantly smaller in size near the poleward (high-latitude) limit of their natural range? When I visited the Royal Ontario Museum in Toronto, they had 2 pinned specimens of Papilio cresphontes on display which were much smaller than their normal size per the article (one had a wingspan of "only" 3 inches -- I did a rough measurement with my fingers against the glass -- and the other was about 1/2 inch bigger) -- is this normal for (1) specifically P. cresphontes, (2) all swallowtails, and/or (3) all or most butterfly species? 2601:646:8082:BA0:9480:50AE:ABF3:5E17 (talk) 23:38, 17 May 2024 (UTC)[reply]

Size Distributions of Butterfly Species and the Effect of Latitude on Species Sizes (you can open a free JSTOR account or access through the Wikipedia Library). Alansplodge (talk) 10:10, 18 May 2024 (UTC)[reply]

Sorry, I won't click on any external links regarding this topic, just in case it might show me gratuitously enlarged pictures of P. multicaudata or some suchlike abomination -- can you just tell me the gist of it in a few words (or more than a few, your choice)? 2601:646:8082:BA0:E558:16C8:D2DE:51EF (talk) 10:31, 18 May 2024 (UTC)[reply]

There are no pictures, it's a scientific paper. "For butterfly species (Papilionoidea) of the Australian and Afrotropical regions, average wingspan decreases with increasing latitude". Alansplodge (talk) 10:34, 18 May 2024 (UTC)[reply]

Thanks! So the answer is yes -- right? (And that would explain the unusually small size of the two P. cresphontes specimens at the museum -- they must have been caught locally, and Toronto is near the northern limit of this species' natural range! And that is also quite reassuring for me -- it means that in Portland, Maine where I've been planning to move for quite a while, any P. cresphontes I come across won't be scary huge, in fact I might actually come to like them!) 2601:646:8082:BA0:E55E:2854:FEDE:FEB6 (talk) 21:21, 18 May 2024 (UTC)[reply]