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January 19

Observatory

From what I've read, this building in the background is some unspecified observatory rather than lighthouse. The photo is no later than 1991, around 1986. Do we know what observatory exactly? Assuming it's the same building, also this. Brandmeister^talk 09:56, 19 January 2025 (UTC)[reply]

I don't see how anyone can tell given the lack of context, and I don't think they are the same building. They are very small so probably belong to a school or college. Shantavira|^{feed me} 12:20, 19 January 2025 (UTC)[reply]

I'm pretty sure that both pictures were taken at Calar Alto Observatory. The second one is the 2.2m telescope [1], the first one probably the 1.23m telescope [2]. --Wrongfilter (talk) 12:36, 19 January 2025 (UTC)[reply]

Thanks. Brandmeister^talk 08:48, 20 January 2025 (UTC)[reply]

Bodies reflecting light are to stars, what (...?) are to black holes.

Black holes can, in some sense, be described as antistars, insofar the latter emit light, whereas the former absorb it. Various celestial bodies, such as planets and satellites, or comets and meteors, reflect starlight, thereby becoming secondary light sources. What (theoretical) astronomical objects relate to black holes, in a manner analogous to the one to which the latter relate to stars ? — 86.125.205.116 (talk) 13:15, 19 January 2025 (UTC)[reply]

An anti-black hole would be a white hole, which cannot absorb but only emit light. While never observed, they are possible in the sense of being a solution to the Einstein field equations. Also, stars not only emit but also do absorb and reflect light. If you shine with a flashlight at the Sun, it will become brighter. It will take some 8 minutes for the light from the flashlight to reach the Sun and another 8 minutes for the reflected light to travel back to Earth. If you don't notice the effect, it is only because it is too minuscule to be perceptible (even to the best instruments).

Ignoring all this, I can think of two possible schematic approaches.

1. star (emits but does not absorb light) : planet (both emits and absorbs light)

= black hole (does not emit but absorbs light : X (neither emits nor absorbs light)

X could be a region of totally empty space.

2. star (emits light) : planet (emits and absorbs light)

= black hole (absorbs light) : X (absorbs and emits light)

The solution to this approach can be X = planet, so in this schematic approach planets are Majorana bodies. --Lambiam 00:08, 20 January 2025 (UTC)[reply]

You also absorb light. Go stand outdoors during a sunny day: that's you, absorbing a star's light. You emit "light" too, just at longer wavelengths down in the infrared. (This is how many snakes hunt, by looking for this infrared prey gives off.) And so do planets and asteroids etc; they also reflect light which can "outweigh" the amount they emit as black-body radiation. Anything hotter than the cosmic microwave background, the "temperature of the universe", emits photons. Stars do this in shorter wavelengths (thus "glowing" in the range that our faceholes can pick up) than you or me because they're hot. Like a piece of hot metal glows, because it's hot. See black-body spectrum.

For that matter cosmologists have come to believe black holes do emit photons; they're just really really long-wavelength ones, well outside the visible spectrum. There's nothing "magic" about black holes. They just are incredibly dense and thus have correspondingly strong effects on their surrounding spacetime—but the same can be said of planets and stars, just at a lesser degree. Stars even noticeably "bend" light! (Maybe the sought-for answer is the elusive dark sucker?) --Slowking Man (talk) 05:52, 23 January 2025 (UTC)[reply]

January 20

Did Jagadish Chandra Bose discovered Turgor pressure?

I am trying to find history of Turgor pressure. Did Jagadish Chandra Bose discovered Turgor pressure? HarryOrange (talk) 04:46, 20 January 2025 (UTC)[reply]

I find the term used here in a textbook of plant physiology from 1903, which predates Bose's investigations. --Lambiam 11:23, 20 January 2025 (UTC)[reply]

January 22

Does the average man refractory period during sex different from masturbation?

A man, after cumming during solo masturbation (with or without porn use) those 3 things happen:
1-The dick will become soft and the man will need X minutes to be able to maybe become hard again.
2-The guy will start to think "thats was good but I will do something else with my life" and will not be able to feel the desire to continue something that was extremely pleasurable 0.5 seconds ago, and after Y minutes he will be able to have the desire to do it again.
3-If he wait Y minutes he will have the desire to do it again as I said, but he doesnt even have the desire to wait those Y minutes to make the desire come back.
This happen with me during masturbation, but during sex, step 2 (and so step 3) doenst happen, and I can go back to do it immidiatelly, less 0.1 second after cummming. But of course my dick will be soft during the next X minutes and I will have to use my hand and tongue or whateaver during that time. This apply even if the girl was just giving me oral and nothing more.
My question is, does the average guy refractory period during sex works different from masturbation like me (doenst have step 2 and also 3) or it works exactly like masturbation (have step 2 and 3) and I not like the average guy (if thats the case "THANKS GOD" I dont work the other way)?2804:1B3:9702:35F6:6D57:AC7C:50EF:36FA (talk) 03:25, 22 January 2025 (UTC)[reply]

The refractory period is entirely physiological and any psychological events are entirely psychological. Abductive (reasoning) 06:10, 22 January 2025 (UTC)[reply]

January 26

Other language Latin names

Do countries that speak Arabic, Khmer, and Chinese use the Latin names with the Latin alphabet when talking about biology? Do they insert these into their language despite the different alphabet? 2601:644:907E:A70:5020:3050:C038:F1A3 (talk) 18:44, 26 January 2025 (UTC)[reply]

It is more appropriate to call these names binomial or scientific names because that makes it clear that these are internationally agreed and accepted names that are not restricted to any particular language. Another clue can be obtained by checking articles on some species in other wikipedias. Here are the equivalents to Human in Chinese, Khmer, Farsi and Arabic. All have scientific names (for various taxonomic levels) sprinkled in the text, indicating that it is quite common not to transcribe (or transliterate?) those names (I cannot exclude, however, that they give the Latin script in addition to a transcription). --Wrongfilter (talk) 19:15, 26 January 2025 (UTC)[reply]

As above and as the article indicates they are pretty universal. That someone might call them "Latin" names shows they are as "foreign" to English speakers as to speakers of other languages. And they are respectful of other countries' scientific endeavours in that names are based on first discovery of the species. So there's e.g. Zhuchengtyrannus named after Zhucheng, a place in China. --2A04:4A43:909F:F990:55A5:C8A2:87C3:73CF (talk) 00:27, 27 January 2025 (UTC)[reply]

ar:أيل الماء and zh:獐 both include the text Hydropotes inermis when talking about the water deer. Can't cite a Khmer article, since the Khmer Wikipedia is rather small, and it's hard to find articles about any specific subject in a completely alien language. Nyttend (talk) 05:37, 29 January 2025 (UTC)[reply]

A few examples of pages on the Khmer Wikipedia with binomial names in the Latin alphabet: កណ្ដុរ, គោព្រៃ, ទន្សោង, កន្ថឹក, ស្វាកន្ទុយស. --Lambiam 10:03, 29 January 2025 (UTC)[reply]

January 29

Inert waste = less expensive

From inert waste, discussing its lack of decomposition:

This has particular relevance to landfills as inert waste typically requires lower disposal fees than biodegradable waste or hazardous waste.

Why? If it decomposes, doesn't that generally mean that it occupies less space in the landfill in the long run, freeing up more room than something that can be expected always to retain its current size and shape? Last year I took a trailer-load of materials to my local tip (City of Frankston) and found that they charged far, far less to dump a trailer-full of greenwaste than if the same trailer were filled with general waste, including the bits of concrete blocks that I was dumping. Nyttend (talk) 05:41, 29 January 2025 (UTC)[reply]

From the perspective of landfill design, they are bioreactors. They heave and settle, emit gas, and leak leachate. This has to be dealt with for decades. Inert waste doesn't do that. So I guess it is cheaper to deal with, I don't know if that is reflected in the fees. Abductive (reasoning) 07:16, 29 January 2025 (UTC)[reply]

I suspect that greenwaste brought to your local waste disposal centre is not dumped in a landfill, but used for composting or bioenergy, thus being a source of revenue that covers some of the cost of dealing with the waste. --Lambiam 09:37, 29 January 2025 (UTC)[reply]

Indeed. [3] All green waste from [Frankston Regional Recycling and Recovery Centre] is bulk composted and blended near Sale to be used by farmers throughout South East Victoria. AlmostReadytoFly (talk) 14:28, 29 January 2025 (UTC)[reply]

"One man's waste is another man's raw material", as Sir Harry King might have said. {The poster formerly known as 87.81.230.195} 94.7.205.116 (talk) 22:45, 29 January 2025 (UTC)[reply]

The landfills around where I live attempt to collect biodegradable waste to one side where it is covered and the gas is collected, converted to natual gas, and sold. The profits they make from the RNG sales allow the county to use the landfill for free. In fact, the landfills compete for service. My neighborhood has garbage collection from one of them. Our HOA pays $60/year for the service. Then, in the winter, the gas cooperative for our neighborhood ends up purchasing their gas to heat the homes. 12.116.29.106 (talk) 15:00, 30 January 2025 (UTC)[reply]

January 31

human eye and visible spectrum range

https://en.wikipedia.org/wiki/Visible_spectrum Here it is mentioned that A typical human eye will respond to wavelengths from about 380 to about 750 nanometers. Maverick 9828 (talk) 09:07, 31 January 2025 (UTC) And here https://science.nasa.gov/ems/09_visiblelight/#:~:text=What%20is%20the%20visible%20light,from%20380%20to%20700%20nanometers. in NASA website it mentions that Typically, the human eye can detect wavelengths from 380 to 700 nanometers. So should I edit Wikipedia? — Preceding unsigned comment added by Maverick 9828 (talk • contribs) 09:09, 31 January 2025 (UTC)[reply]

No. The reference in the wikipedia article is a biology textbook, which is a better reference for a statement that pertains to physiology than a popularising web page from a space agency. --Wrongfilter (talk) 09:13, 31 January 2025 (UTC)[reply]

yeah a textbook from '2005' and a website of a 'leading space agency' that deals a lot with Electromagnetic spectrum.. so it is counterintuitive... Maverick 9828 (talk) 09:19, 31 January 2025 (UTC)[reply]

But this is not about the electromagnetic spectrum, it is about the human eye (neither of which has changed much since 2005...). --Wrongfilter (talk) 09:30, 31 January 2025 (UTC)[reply]

nature.com agrees with 750 but starts with 390 and not 380.

there are just so many studies that all are true in themselves. So we can't provide a single range. anyways Thanks Maverick 9828 (talk) 10:01, 31 January 2025 (UTC)[reply]

As the article visible spectrum points out, the boundaries vary between individuals and according to conditions. So one should expect some variation between sources. Double sharp (talk) 10:06, 31 January 2025 (UTC)[reply]

you're right. Maverick 9828 (talk) 10:08, 31 January 2025 (UTC)[reply]

The ability to detect fades off rapidly as the wavelength passes 700 and there is no sharp cutoff. I can see a 850 nm near infrared LED as red, but it does not mean we have to update the article. Graeme Bartlett (talk) 12:06, 31 January 2025 (UTC)[reply]

I should change the article about human hearing to put the upper limit at 13KHz as that's about all I can hear these days :-( NadVolum (talk) 12:17, 31 January 2025 (UTC)[reply]

Can you supply a RS for the presumption that your hearing is human hearing? --Lambiam 20:49, 31 January 2025 (UTC)[reply]

I'm pretty certain I can prove I'm a human for you. 🤖 er I mean 😀 NadVolum (talk) 21:55, 31 January 2025 (UTC)[reply]

Typically, when reliable sources give different information, they can both be quoted. Also note that the original version you're describing has a built-in fudge factor, the word "about". ←Baseball Bugs ^{What's up, Doc?} carrots→ 02:46, 1 February 2025 (UTC)[reply]

Antenniferous tubercles?

Apparently, Xystrocera globosa has antenniferous tubercles scarcely projected. ([4], p 224) This information would be more valuable if I knew what an antenniferous tubercle was. According to this book, it means one thing in aphids and another in hemiptera, but X. globosa is a beetle. Are these the tubercles that bear the antennae, or are they merely rather close to the antennae?

Thank you for any advice you can provide. Cremastra (talk) 15:28, 31 January 2025 (UTC)[reply]

Since the Aphididae are a family that belongs to the order Hemiptera, the definitions in the Dictionary of Insect Morphology are ambiguous.

Just like ciliferous means “bearing cilia”, coniferous means “bearing cones”, and ovuliferous means “bearing ovules”, we may expect antenniferous to mean “bearing antennae”. It is hard to make out whether the entomologist(s) qualifying the tubercles of the order Hemiptera in general with this adjective were myopic, or confused as to the sense of -(i)ferous, or what. --Lambiam 20:13, 31 January 2025 (UTC)[reply]

February 2