Content deleted Content added

Inline

Revision as of 06:45, 6 May 2021

Welcome to the science section
of the Wikipedia reference desk.

skip to bottom

Select a section:

Shortcut

WP:RD/S

Want a faster answer?

Main page: Help searching Wikipedia

How can I get my question answered?

Select the section of the desk that best fits the general topic of your question (see the navigation column to the right).
Post your question to only one section, providing a short header that gives the topic of your question.
Type '~~~~' (that is, four tilde characters) at the end – this signs and dates your contribution so we know who wrote what and when.
Don't post personal contact information – it will be removed. Any answers will be provided here.
Please be as specific as possible, and include all relevant context – the usefulness of answers may depend on the context.
Note:
- We don't answer (and may remove) questions that require medical diagnosis or legal advice.
- We don't answer requests for opinions, predictions or debate.
- We don't do your homework for you, though we'll help you past the stuck point.
- We don't conduct original research or provide a free source of ideas, but we'll help you find information you need.

Ready? Ask a new question!

How do I answer a question?

Main page: Wikipedia:Reference desk/Guidelines

The best answers address the question directly, and back up facts with wikilinks and links to sources. Do not edit others' comments and do not give any medical or legal advice.

April 30

Selenocosmia crassipes

Am I seeing this right? Does it really have nine legs? (In the photo [here], it seems to have nine legs.)— Preceding unsigned comment added by 32.209.109.127 (talk • contribs)

Could be a random mutation, or maybe, if it's a species capable of limb regeneration, it lost one of its legs previously and the regrowth went somewhat awry. PaleCloudedWhite (talk) 00:49, 30 April 2021 (UTC)[reply]

The seeming extra leg at the head end is not a leg, but one of the spider's two pedipalps, which are relatively larger in this species than is the case in many others.

Spiders, formally the Order Araneae, are part of the Class Arachnida, in turn part of the Subphylum Chelicerata: as you will see from the diagrams in that last-linked article, different members of the subphylum have different numbers of paired appendages, which include legs, pedipalps and chelicerae, which in spiders are their fangs. These might be thought of as variations on a similar theme, much less distinct in origin than the fins, barbels and jaws of a bony fish, for example, let alone a fish descendant such as ourselves. {The poster formerly known as 87.81.230.195} 90.200.135.95 (talk) 01:09, 30 April 2021 (UTC)[reply]

So, my question then is does this spider have an injury meaning it lost a pedipalp, or is this a species where one pedipalp grows much larger than the other? Such asymmetry is not unknown in various animals, narwhals and fiddler crabs come to mind. --Jayron 32 18:05, 30 April 2021 (UTC)[reply]

I'm pretty sure the other pedipalp is just momentarily folded under the head and thus hidden: web-searching for pictures of the species (and for other comparable spiders) finds a good proportion showing one or both pedipalps thus hidden/positioned. Pedipalps are more flexible and mobile than the legs since they're used to feel out the immediate terrain and to convey food to the mouth: videos (several are similarly findable) will probably show them in action. {The poster formerly known as 87.81.230.195} 90.200.135.95 (talk) 22:20, 30 April 2021 (UTC)[reply]

May 1

Proning

Indian media is giving huge coverage to prone breathing. I want to know whether American, European media published any article on this, as I can't find much coverage by international media.

https://indianexpress.com/article/lifestyle/health/self-proning-improving-oxygen-levels-step-by-step-guide-health-ministry-7289951/

One of the cited references in our proning article is from the New York Times'. DMacks (talk) 05:22, 1 May 2021 (UTC)[reply]

And the second is from The Times (of London). The issue has been mentioned before on the RD (Wikipedia:Reference desk/Archives/Science/2021 January 14 § obese people to lie down on their sides). The news articles are about the practice as executed by medical professionals in a context of hospital care, while the recent articles in the Indian media cover "self-proning" by patients at home. In most countries in the "Western world", patients are hospitalized when oxygen saturation becomes an issue, so one would not expect European and American media to cover self-proning, or, at least, not as a topic having practical importance to their readership. --Lambiam 12:55, 1 May 2021 (UTC)[reply]

In a hospital context:-

I also found How to self prone by a doctor employed by a British pillow manufacturer.

Alansplodge (talk) 14:16, 1 May 2021 (UTC)[reply]

Highly inappropriate and irrelevant content

The following discussion has been closed. Please do not modify it.

It didn't do much good for Eric Garner. ←Baseball Bugs ^{What's up, Doc?} carrots→ 14:59, 1 May 2021 (UTC)[reply]

Was that at all necessary or appropriate? --OuroborosCobra (talk) 05:04, 2 May 2021 (UTC)[reply]

It contradicts the premise. ←Baseball Bugs ^{What's up, Doc?} carrots→ 09:28, 2 May 2021 (UTC)[reply]

No, it doesn't. Normal sleeping prone doesn't involve someone having an arm around their necks. What you did was a flippant comment about someone who was murdered that's entirely irrelevant to the topic other than for to display casual cruelty. --OuroborosCobra (talk) 12:52, 2 May 2021 (UTC)[reply]

Yes, it does. Someone with a fat belly lying prone is not going to be comfortable, whether he's being murdered by cops or is voluntarily lying there. ←Baseball Bugs ^{What's up, Doc?} carrots→ 17:06, 2 May 2021 (UTC)[reply]

May 2

Does bodybuilders have extra muscles?

From here it says Bodybuilding is the use of progressive resistance exercise to control and develop one's musculature (muscle building) by muscle hypertrophy for aesthetic purposes. Does it mean they possess extra muscles ? Rizosome (talk) 03:42, 2 May 2021 (UTC)[reply]

Did you read the article past the first sentence? Or to the linked article on muscle hypertrophy? --OuroborosCobra (talk) 05:03, 2 May 2021 (UTC)[reply]

That quoted sentence does not suggest the growth of any extra muscles. Maybe an afterthought. Under "Performance-enhancing substances" in the article there is a "muscle lacking" statement, it's a probable misappropriation or otherwise a typo - "muscle lagging". --Askedonty (talk) 08:55, 2 May 2021 (UTC)[reply]

What is said to be possibly lacking in that sentence, is "the appearance of developed muscle". This is not lacking in the sense of being absent, but in the sense of not meeting some desired quality level, as in, "he was hired as a teacher but was found lacking." --Lambiam 17:58, 2 May 2021 (UTC)[reply]

So it's the appearance which is lacking. Then the answer is definitely no. @Rizosome: it is to be distinguished between muscle vs. muscles. --Askedonty (talk) 20:31, 2 May 2021 (UTC)[reply]

@Askedonty: Does it mean bodybuilder have muscle mass than a normal person?

The term muscle has both a countable sense (an organ of the human body, as used in the sentence "the human body has more than 600 different muscles") and an uncountable sense (a type of tissue, as in "I'd like to put on some more muscle"). Muscle building – which is what bodybuilders do – involves an increase in the muscle mass, specifically skeletal muscle. --Lambiam 17:52, 2 May 2021 (UTC)[reply]

@Lambiam: interesting, does it mean bodybuilders have very thick arteries and veins than normal person? Rizosome (talk) 05:28, 3 May 2021 (UTC)[reply]

It does not mean that. The walls of arteries and veins contain smooth muscle, which is another type of muscle than skeletal muscle. --Lambiam 08:43, 3 May 2021 (UTC)[reply]

Radiative forcing of clouds on the upper atmosphere

I have been trying to find discussion on this question, but couldn't find anything. Is there any scientific research on the effects solar/thermal radiation reflected upwards by low-level clouds [or by the ground] has on the upper troposphere/the stratosphere? Jo-Jo Eumerus (talk) 13:52, 2 May 2021 (UTC)[reply]

Would that not be covered under something like albedo? I could be wrong; not directly my area of scientific specialty, and even what I do know more mechanistically about climate change is more focused on molecular vibrations than this topic. We do have an article on cloud albedo which has peer-reviewed publications in its references. --OuroborosCobra (talk) 14:21, 2 May 2021 (UTC)[reply]

Sure, but all discussions about "albedo" are about the reflected radiation being reflected into space, not about what happens to the atmosphere above the albedo surface. JoJo Eumerus mobile (main talk) 19:29, 2 May 2021 (UTC)[reply]

Wouldn't that end up being the same thing as light interactions coming from space in the first place? If the light reflected by cloud albedo has not significantly changed in wavelength, i.e. still being mostly visible light, it should be almost entirely reflected back into space. If it is changing wavelength significantly, such as what happens when light doesn't hit that highly reflective surface, and instead radiates at a longer, infrared wavelength, then the same thing would occur as if it had hit the ground and done that (which is where we get to my friendly molecular vibrations). --OuroborosCobra (talk) 21:00, 2 May 2021 (UTC)[reply]

No, because the light from space is homogeneous and mostly stable over time while albedo varies with time and space. That's the key thrust of my question, actually - whether changes in clouds and ground properties can influence the stratosphere/troposphere via the radiation reflected upwards. Jo-Jo Eumerus (talk) 09:14, 3 May 2021 (UTC)[reply]

Light from the sun is neither stable nor homogeneous. It is stable in that its intensity varies with regularity (solar cycle), but it is still varying. It can be somewhat described as continuous, but not homogeneous. It varies tremendously in intensity across the EM spectrum. See the solar irradiance spectrum at our article on sunlight. First off, simply due to its spectrum being close to that of black body radiation, it's strongest intensity is in the visible light region, with some in ultraviolet, and greatly decreasing in intensity as one goes to longer wavelengths. The lack of being a homogeneous light source was one of the primary motivations for the discovery of quantum mechanics, as classical mechanics had predicted black body radiation would be homogenous, when it isn't. Solar irradiance includes little direct intensity in the infrared region that is so important for greenhouse gases. This, again, is why albedo (or lack thereof) is so important in the discussion of climate change. With high albedo, visible light is reflected back into space. It wasn't being strongly absorbed on its way down the atmosphere, is not being absorbed by the reflective object, and isn't being absorbed on its way back out. Low albedo, on the other hand, often sees the visible light absorbed and then re-radiated at longer wavelengths, such as into the infrared. This IR radiation can then be absorbed by gas molecules with either permanent or transient dipoles with respect to nuclear coordinate motion, i.e. increasing kinetic energy and heating. --OuroborosCobra (talk) 12:26, 3 May 2021 (UTC)[reply]

isn't being absorbed on its way back out See, this is what this question is about - do we know for certain that the reflected radiation has no effect on the way out? Jo-Jo Eumerus (talk) 10:03, 4 May 2021 (UTC)[reply]

Essentially, yes. If it is true reflection, or even elastic scattering, then we do know that it isn't being absorbed on its way out because it wasn't absorbed on its way down. Passing light of the same wavelength multiple times through the same medium that didn't absorb it the first time will not result in new absorption. Indeed, the incredibly common industrial use of absorption spectroscopy is essentially dependent upon this. The fact that lemonade is yellow whether you observe it now or 5 seconds from now is dependent upon this property. If the wavelength of the scattered or reflected light changes from that of the incident radiation, that's a different matter, but we seem to be discussing true reflecting. Lower albedo materials, rather than high albedo, are the ones that change the wavelength of the re-emitted light. --OuroborosCobra (talk) 14:32, 4 May 2021 (UTC)[reply]

I'm sure it has been studied, since a simple model of the atmosphere using low cloud good, high cloud bad, as far as greenhouse effect goes, would suggest that the patch of air between the two (tropical upper troposphere) should warm. The relatively small increase that has been found does not agree with that predicted by "any color you like so long as it is CO2" models. Here's some articles

[vi] Douglass DH, Christy JR, Pearson BD, Singer SF. A comparison of tropical temperature trends with model predictions. Int J Climatol 2008, 27:1693–1701

[vii] Santer, B.D.; Thorne, P.W.; Haimberger, L.; Taylor, K.E.; Wigley, T.M.L.; Lanzante, J.R.; Solomon, S.; Free, M.; Gleckler, P.J.; Jones, P.D.; Karl, T.R.; Klein, S.A.; Mears, C.; Nychka, D.; Schmidt, G.A.; Sherwood, S.C.; Wentz, F.J. Consistency of modelled and observed temperature trends in the tropical troposphere. Int. J. Climatol. 2008, doi:1002/joc.1756

[viii] McKitrick, R. R., S. McIntyre and C. Herman (2010) “Panel and Multivariate Methods for Tests of Trend Equivalence in Climate Data Sets.” Atmospheric Science Letters, 11(4) pp. 270-277, October/December 2010 DOI: 10.1002/asl.290

[ix] Christy, J. R., B. M. Herman, R. Pielke Sr., P. Klotzbach, R. T. McNider, J. J. Hnilo, R. W. Spencer, T. Chase, and D. H. Douglass (2010), What do observational datasets say about modeled tropospheric temperature trends since 1979?, Remote Sens., 2, 2148–2169, doi:10.3390/rs2092148

Greglocock (talk)

I'm not sure those articles are suggesting that any and all light play significant roles in heating. Light/matter interactions are generally dependent on some sort of resonance between the energy of the light and an energy level difference in the matter. The reason why IR light has such a big role in heating the atmosphere is that the light at those energies is resonant with the vibrational energy levels of the gases in the atmosphere. Obviously, I am oversimplifying, there are other selection rules that come into play (this being why nitrogen gas is not a greenhouse gas, but carbon dioxide is), and other things like vibronic coupling that could result in vibrational excitations in visible light wavelengths. The point being, though, that without being resonant, the light will not interact with matter, generally speaking. If you have resonance, especially with vibrational energy levels, that can result in motion (vibrational, in this case), and therefore kinetic energy, which we measure in a system as increase in temperature. --OuroborosCobra (talk) 00:50, 3 May 2021 (UTC)[reply]

Damage by spike protein

SARS-CoV-2 spike protein makes that virus genes can enter cell and replicate. Spike protein can also damage lung and other tissue (proved in Syrian hamsters but is believed also in humans) what can explain very many different faces of COVID-19 such like causing thrombosis. (https://www.ahajournals.org/doi/10.1161/CIRCRESAHA.121.318902) Some vaccines make cells produce spike proteins. Does this mean they can cause same kinds of damage? Will this be researched? Thank you. Hevesli (talk) 22:36, 2 May 2021 (UTC)[reply]

I'm thinking, based on your post, that you may have a bit of a language barrier issue. Spike proteins do not make virus genes. As for the many different symptoms and ill effects of COVID19, this has to do with the fact that the ACE2 receptor that the spike protein binds to is found throughout the body in very different types of cells. Any cell with an ACE2 receptor presents a possible target for SARS-CoV-2 infection. The primary role that the spike protein plays is just binding to ACE2, allowing entry into the cell. Your article does indicate some other effects that binding to ACE2 has... but I imagine these would be fairly short lived without continued replication of virus or spike protein material. The mRNA vaccines do cause our cells to make spike proteins, but not for a very long time. Nothing is making new mRNA with the right sequence after you are given a shot, so once the mRNA has broken down, you are not making new spike proteins, and the existing ones will eventually breakdown as well. The point isn't to flood the body with spike proteins on a long-term basis, rather, the intent is just to train the immune system to recognize the spike proteins. Completely guessing on my part, but perhaps the minor ill effects that people sometimes experience after receiving the vaccine is related to what you found in that article. --OuroborosCobra (talk) 00:42, 3 May 2021 (UTC)[reply]

Thank you. In my opinion, the possibility that the proteins produced by the mRNA vaccine may themselves cause damage deserves further investigation. Pfizer-BioNTech's spike protein and AstraZeneca's spike protein have differences and may have different side-effects. In order that the virus genes can enter the cell, the spike protein must bind to the ACE2-receptor. Without spike binding, virus genes cannot enter. The spike protein makes that the genes can enter. Hevesli (talk) 08:44, 3 May 2021 (UTC)[reply]

In the preview of the study you link, it says that the spike protein can damage vascular endothelial cells by downregulating ACE2 and consequently inhibiting mitochondrial function. I do not see a direct link from that to thrombosis, as the OP seems to suggest (but maybe the link is obvious to a topic expert). Our article does not make such a link either, even though it addresses ACE2 and thrombosis (see COVID-19#Pathophysiology).

"Will something be studied by researchers" is speculation. It is unlikely that there is any research funding tied to that exact study, but if it looks interesting enough researchers will likely have a look at it. If you stretch the definition enough, the answer is "yes", because both vaccines you mention passed phase III clinical trials, and are currently undergoing phase IV (post-market surveillance); with millions of patients treated, side-effects (of any kind) will be picked up even if not explained at the cell level. Tigraan^{Click here to contact me} 09:04, 3 May 2021 (UTC)[reply]

May 4

Red blood cell production following blood loss

Hi. Multiple sources say that the about 2 million new red blood cells are created every second in the human body under normal circumstances. But what is the corresponding figure when the body needs to replenish its red blood cells following significant blood loss? Thanks.

I seem to recall that the body does not increase the rate of production of rbcs, but rather decreases the rate of destruction of rbcs in the spleen until the low blood count is improved. Abductive (reasoning) 01:02, 4 May 2021 (UTC)[reply]

What does "acceleration" purpose in mechanics?

We say acceleration due to gravity is 9.8 m/sec2. But I say speed of freely falling object on Earth is equal to 9.8 m/sec without using acceleration. So What does "acceleration" purpose in mechanics? Rizosome (talk) 07:05, 4 May 2021 (UTC)[reply]

9.8 m/sec² can be said as "nine point eight meters per second, per second", meaning that the velocity increases by 9.8 m/s every second (ignoring air resistance). That's the difference between velocity ("speed") and acceleration. Speed is a constant, whereas velocity isn't. 2603:6081:1C00:1187:1110:9627:D5D8:97F4 (talk) 07:14, 4 May 2021 (UTC)^[reply]

You must have meant to write "Acceleration is constant", not "speed is a constant", I think. Jmchutchinson (talk) 19:25, 4 May 2021 (UTC)[reply]

What about speed of freely falling body? Is it undetermined? Rizosome (talk) 07:22, 4 May 2021 (UTC)[reply]

The speed will change (accelerate) until terminal velocity is reached.--Shantavira|^{feed me} 07:46, 4 May 2021 (UTC)[reply]

So for a free falling object have two values: speed and velocity? Rizosome (talk) 07:51, 4 May 2021 (UTC)[reply]

Speed and velocity are essentially the same thing. Acceleration is change in speed over time. ←Baseball Bugs ^{What's up, Doc?} carrots→ 11:10, 4 May 2021 (UTC)[reply]

If there was no air resistance then a falling object would accelerate with 9.8 m/sec² until hitting the ground. That means that if it starts at rest then after 1 second it would have velocity 9.8 m/sec. After two seconds it would be 19.6 m/sec. After 3 seconds it would be 29.4 m/sec, and so on. (Some small factors are ignored here). PrimeHunter (talk) 11:21, 4 May 2021 (UTC)[reply]

As noted in Gravitation of the Moon, its number is 1.625 m/s². Since there is almost no atmosphere on the Moon, any object falling toward the Moon will continue to accelerate at that rate until it hits the surface. ←Baseball Bugs ^{What's up, Doc?} carrots→ 11:30, 4 May 2021 (UTC)[reply]

I don't really understand this. A quadratic equation (involving x squared) presents on a graph as a parabola. If you plot the figures presented by PrimeHunter (velocity against time) they present as a straight line. 95.148.229.85 (talk) 13:11, 4 May 2021 (UTC)[reply]

The quadratic equation graph is of displacement(i.e. distance covered) against time and Prime hunter told about velocity against time which plots as straight line -- Parnaval (talk) 13:24, 4 May 2021 (UTC)[reply]

So is the velocity increasing at a uniform rate or not? If it's plotted against seconds (1, 2, 3 etc) then it's a straight line, but if it's plotted against seconds squared it can't be - after 1 second the velocity is x, after 2 seconds 4x, after 3 seconds 9x, and so on. 95.148.229.85 (talk) 13:52, 4 May 2021 (UTC)[reply]

The velocity is increasing at a constant rate; if you plot the speed vs. time on a graph (assuming acceleration is in the same direction as the motion) then the line will be straight and the slope of the line is the acceleration. If the line were not straight, that would mean that the acceleration were changing, and then we go another level deeper, there's a function called Jerk, which is the change in acceleration over time, and ITS units would be distance per unit time cubed (i.e. m/s/s/s or m/s³). There are even functions if jerk varies with time, see Fourth, fifth, and sixth derivatives of position, and after that it's turtles all the way down. --Jayron 32 13:58, 4 May 2021 (UTC)[reply]

If it had been presented as 9.8 metres per second per second I think that would have been clearer. 95.148.229.85 (talk) 14:02, 4 May 2021 (UTC)[reply]

Maybe. m/s² = m/(s⋅s) = (m/s)/s. Physicists prefer to only write a unit once, and often to use negative exponents instead of division. m/s² = m⋅s⁻². It can get much worse. From farad: In SI base units 1F = 1s⁴⋅A²⋅m⁻²⋅kg⁻¹. PrimeHunter (talk) 14:27, 4 May 2021 (UTC)[reply]

From a mathematical point of view, it makes no difference. The notation is unconnected to the operation, and you can write it as m/(s^.s) or m/s² or m/s/s or (m/s)/s or m^.s^-2 or whatever works for you. It's all the same. It's the distance, divided by time, divided by time again. Or square the time and take the distance and divide it by the result of that. As long as the dimensional analysis works out, it's acceleration if the units reduce to m/s². Now, the meaning of that acceleration changes depending on how you calculate it; it can be instantaneous acceleration or average acceleration (of which there are several ways to mean "average") or initial acceleration, or whatever, and the meaning of the calculation will change depending on the method used to calculate it (including being relatively useless for modeling real behavior...) but it's still acceleration if it's got that set of units. --Jayron 32 11:56, 5 May 2021 (UTC)[reply]

Primehunter actually reminded me of a side discussion I sometimes hold in my chemistry class when we discuss the universal gas constant and why it shows up BOTH in the ideal gas law, AND in several different equations where energy pops out. The units of the standard form of the gas constant, R, are something like (liter^.kPa)/mole^.K) when you use it in the Ideal Gas Law, but are something like J/mole^.K when you use it in thermodynamics applications, and the reason for that is that volume times pressure is energy. The fact that this doesn't seem to make physical sense (volume and pressure are bulk properties of a gas, whereas energy tells you something about how an object will move) is not really that important here; volume times pressure is energy because the units are the same (energy is J, which is a N^.m, and since a Newton is a kg^.m/s² that means a joule is a kg^.m²/s². Pressure is measured in pascals, which is N/m². That's means a pascal is a kg/m^.s² and volume is m³. So pressure times volume has units of kg^.m²/s² the same as energy, QED. --Jayron 32 12:08, 5 May 2021 (UTC)[reply]

I agree with Jayron32! Bernoulli's principle is sometimes written as follows:

{\rho }{\frac {v^{2}}{2}}+\rho gz+p={\text{constant}}

where the first term is the kinetic energy of a unit volume of fluid; the second term is the potential energy of a unit volume; and the third term is simply static pressure. It shows that static pressure is a measure of some of the energy in a unit volume of fluid. Dolphin (t) 12:32, 5 May 2021 (UTC)[reply]

One of the things that makes energy so hard to grasp as a concept is that energy is not itself observable, it is an abstract property of a system, and it isn't "stored" or "created" and doesn't really even have an existence, though we tend to visualize it as a fluid that can move from place to place or some substance we can store like phlogiston or caloric or Luminiferous aether or something like that, it's just a number we assign to a system that quantifies how much that system has the potential to cause a change to occur. Energy as a concept has certain mathematical properties and symmetries that make it a conserved quantity, and that make it a transferable quantity, but it's not a tangible stuff or thing or anything. It's just a number we assign to a system of objects or particles that says "this system has the ability to alter motion in by a certain amount". That number has units of mass times velocity squared, but merely because it has units doesn't mean it is tangible. Any mathematical operation we can do with other measurements that spits out "mass times velocity squared" is, by definition, a calculation of energy content. That energy content can, hypothetically, be transformed into other energy content, though whether that is practical to do or even physically possible is a different story, but it still is all just energy, whether it is the Bernoulli term you brought up, or the pressure times volume of a gas, or a massive object moving at some constant speed, or a photon of light, it's all energy. --Jayron 32 12:43, 5 May 2021 (UTC)[reply]

Etymology of "aeroplane"

The word "aeroplane" was apparently coined by French sculptor and inventor Joseph Pline in 1855. What was that paper? Is it available online? Andy Mabbett (Pigsonthewing); Talk to Andy; Andy's edits 09:47, 4 May 2021 (UTC)[reply]

The term preceded the modern usage.[1] ←Baseball Bugs ^{What's up, Doc?} carrots→ 11:14, 4 May 2021 (UTC)[reply]

The self-published page you link to gives "French aéroplane (1855)... Ancient Greek had a word aeroplanos, but it meant 'wandering in the air'". Andy Mabbett (Pigsonthewing); Talk to Andy; Andy's edits 11:26, 4 May 2021 (UTC)[reply]

Your uncited claim about the origin of "aeroplane" is likewise self-published. ←Baseball Bugs ^{What's up, Doc?} carrots→ 11:46, 4 May 2021 (UTC)[reply]

It was in a patent apparently:

M. Joseph Pline , breveté en juin 1855 , pour un système mixte l'Aéroplane , dont je me réserve de dire quelques mots , avait fait du plan – le nom de son appareil l'indique , - la base d'un système absolument différent de tous ceux qui ont l ' aérostat pour point de départ... Il proposait de construire un appareil dirigeable : - la confiance et l'argent firent défaut ; – et douze années d'efforts furent englouties dans le gouffre du néant , faute de manifestation suffisante.

"Mr. Joseph Pline, patented in June 1855, a mixed aeroplane system, of which I may say a few words, had made the plan - as the name of his device indicates - the basis of a system absolutely different from all those who have the aerostat as a starting point... He proposed to build a steerable apparatus: - trust and money were lacking; - and twelve years of effort were engulfed in the abyss of nothingness, for lack of sufficient demonstration".

Aviation ou Navigation aérienne (p. 167) by Guillaume Joseph Gabriel de LA LANDELLE; Paris, 1863.

I found a "snippet view" of Gothenburg Studies in English, Volume 7 (1958) p. 229:

Pline's design was presented at the Exposition Universelle in Paris in 1855, and an abstract of his patent specification was printed in the catalogue of the exhibition (off - print in the library of the Musée de l'Air, Paris), but it appears to have been too impracticable to have been widely noticed.

Apologies for the rubbish translation, perhaps someone else can do better... Alansplodge (talk) 12:05, 4 May 2021 (UTC)[reply]

I think that the word plan in the first quotation refers back to the plan incliné ("inclined plane") mentioned in the preceding paragraph – where "plane" simply means a flat surface. My attempt at an (also not superb) translation: "Mr. Joseph Pline, who had, in June 1855, obtained a patent for a mixed aeroplane system, of which I may say a few words, had made the plane – as the name of his device indicates – the base of a system ...". --Lambiam 15:55, 4 May 2021 (UTC)[reply]

The 1855 Exposition Universelle official catalogue is here if anyone has time to wade through it. Alansplodge (talk) 12:29, 4 May 2021 (UTC)[reply]

I've done several searches of the text form of that and can't find anything pertinent. Andy Mabbett (Pigsonthewing); Talk to Andy; Andy's edits 15:22, 4 May 2021 (UTC)[reply]

(ec) I've found several references that indicate that the paper in question was actually a patent application (brevet in French). This may be as close as we can get, No.554, 12 June 1855, although this description only mentions appareil aéronautique. And this may contain direct quotes from the patent: la notion de forme plane par opposition à la notion d'aérostat ordinaire sphérique — "the notion of a plane form in contrast to the notion of the ordinary spherical aerostat" (a balloon). --Wrongfilter (talk) 12:12, 4 May 2021 (UTC)[reply]

Further searching has thrown up a mention of Stubelius, Svante (1958). Airship, aeroplane, aircraft: studies in the history of terms for aircraft in English. pp. 226–229.. Google Books only has a preview; IA has nothing. I've requested a copy at WP:REX. Andy Mabbett (Pigsonthewing); Talk to Andy; Andy's edits 15:34, 4 May 2021 (UTC)[reply]

There is also a book Gilbert, Louis (1965). La formation du vocabulaire de l'aviation [The formation of the aviation vocabulary]. Vol. Volume 1. ISBN 9780828867184, {{cite book}}: |volume= has extra text (help) of which I only see snippets, but I think that I have pieced together an essential sentence from the description of the invention in the patent: D'après cette comparaison des différences qui existent entre la forme d'un navire aéroplane et celle d'un aérostat ordinaire, on comprend que cette forme plane, horizontale et tranchante puisse être entraînée dans une direction voulue par des hélices ou organes propulseurs, avec beaucoup plus de facilité que les aérostats sphériques ou cylindroconiques dont la forme n'a aucune analogie avec la fonction que nous cherchons à leur faire remplir. Pline contrasts his aéroplane vessel with an ordinary aérostat, which makes me believe that -plane was meant to be in opposition to the staticity of -stat. Monsieur Gilbert seems equally tempted to believe this. After revealing that (according to an 18th-century etymologist) the component -stat signifies "to remain stationary", he writes on page 118, On serait tenté alors d'opposer plane du verbe planer, qui signifierait « en planant comme les oiseaux ». (One would thus be tempted to see an opposition of -plane from the verb planer, which would signify "gliding like birds". However, the author continues by pointing out that this interpretation can be countered by objections of two different orders. What these are, is hidden behind the veil of GBS. But I find a connection with the (attested) Ancient Greek adjective ἀερόπλανος^[2] not implausible; in writing navire aéroplane, Pline also uses his neologism as an adjective. There is no direct connection between Ancient Greek πλάνος (cognate with "planet") and the French verb planer and Latin planus, except that both may ultimately stem from a Proto-Indo-European root pleh₂-. --Lambiam 17:04, 4 May 2021 (UTC)[reply]

By various dark arts, I have been able to wring out a few more sentences from Monsieur Gilbert's book...

"Cette interprétation peut être contrebattue par des objections de deux ordres. D'abord l'intention de signification du créateur ne semble pas avoir été celle - là; ensuite pourquoi l'élément plane aurait - il pris la forme avec un e plutôt que la forme sans e comme aérostat. En faveur de la thèse de l'élément d'origine verbale, Portier avance les éléments graphe, vore, fère, ou phore comme dans planophore. De telles dérivations suffixales sont courantes dans les vocabulaires scientifiques et techniques. En faveur du second élément à caractère nominal, on pourrait invoquer une forme féminine résultant du rapport de signification avec forme dans le texte du brevet (la marque du genre masculin du signe dans sa totalité résultant de..."

That's all folks! Alansplodge (talk) 22:46, 4 May 2021 (UTC)[reply]

The OED says aeroplane was "formed within English by compounding; partly modelled on a French lexical item". From aero (of, from, or to do with, the air) and plane (a flat surface). DuncanHill (talk) 22:55, 4 May 2021 (UTC)[reply]

Which squares with what Etymology Online says. ←Baseball Bugs ^{What's up, Doc?} carrots→ 23:55, 4 May 2021 (UTC)[reply]

Then I'd really want to know what that "French lexical item" was. --Lambiam 06:17, 5 May 2021 (UTC)[reply]

From the continuation revealed by the dark arts, I see that I misinterpreted the preceding sentence. Given that Pline explains the superiority of his invention as deriving from its "forme plane", Gilbert surmises that one might be tempted to oppose the theory (which he may have mentioned in an earlier passage) that plane refers to the action of planer. But, says Gilbert, if it comes from the forme plane (in which the French adjective plan ("flat") has an ⟨e⟩ because forme is a feminine noun), there should have been no ⟨e⟩ in the masculine aéroplane, just like aérostat has no ⟨e⟩. Furthermore, Gilbert continues, one Portier has pointed out that suffixes derived from verbs often end on ⟨e⟩. (Of the latter's examples, I think planophore is interesting, because -phore is unambiguously derived from the Ancient Greek suffix -φορος.) Clearly, the etymology of aéroplane has been widely discussed, and it seems that Gilbert prefers derivation from the verb planer. As far as I can see, Gilbert does not consider the Greek theory. I see no argument for dismissing it out of hand; I think it deserves serious consideration as being at least one possible explanation for Pline's choice of his neologism. I do not know in which edition of the Great Scott the word ἀερόπλανος first appeared, but it was included in the 1855 edition,^[3] and would not have been hard to find for someone with an elementary understanding of the Greek alphabet. Interestingly, in the earliest use of French aérodrome, from ἀερόδρομος, a synonym of ἀερόπλανος, it referred to a flying machine, "l'aérodrome du professeur Lengley".^[4] --Lambiam 07:23, 5 May 2021 (UTC)[reply]

See Langley Aerodrome. Dolphin (t) 08:15, 5 May 2021 (UTC)[reply]

May 5

Heat pump

[5] If I understand what the specs section of this is saying, you put 1KW of electricity in and about 2.5KW of heat comes out. That is thermodynamically possible because it's a heat pump of course. Does the temperature of the outside air make a big difference to that conversion factor? Is there a standard temperature difference that they rate the things at? My mom (getting up there in years) is chilly all the time and always running electric heaters in the house, so this might be a good thing for her. Thanks. 2602:24A:DE47:BA60:8FCB:EA4E:7FBD:4814 (talk) 07:42, 5 May 2021 (UTC)[reply]

Yes, the graph on this page illustrates that: Looking at the NIBE COP curves versus temperature. At very low outside temperatures (-19 C or -2 F) the efficiency is still around 1.75%. The graph shows how more powerful heat pumps are more efficient at lower temperatures, but slightly less efficient at warmer temperatures meaning that the pump size should be matched to your climate. -- Q Chris (talk) 07:57, 5 May 2021 (UTC)[reply]

See coefficient of performance. Dolphin (t) 08:20, 5 May 2021 (UTC)[reply]

The unit of power is kW, not KW. Capitalisation matters. Even more when using mW and MW.

Efficiency depends on outside temperature. That's already the case for the theoretical maximum efficiency, the Carnot efficiency. The larger the temperature ratio (expressed in absolute temperature), the lower the efficiency of a heat pump.

To reduce greenhouse gas emission, it's good to move from gas heating to heat pumps, so there's a significant push from governments in that direction, but many people are of the opinion that heat pumps fail to deliver to their promises. Most heating in western Europe is required when the outside temperature is between -5°C (because it's rarely colder than that) and +5°C (because you don't need much heating when it's warmer), at a relative humidity of around 90% (because the sea is never far away and warmer than the land). When you try to extract heat from such air, the water vapour in the air turns into ice, providing additional heat, but also clogging the heat exchanger. That makes it hard to extract a lot of heat from cold, moist air. Heat pumps use electrical resistors as backup heat source if they can't get enough heat from the air. Something to think about.

BTW, is your mom's house well insulated? Getting better insulation usually pays off more than getting better heating. PiusImpavidus (talk) 08:57, 5 May 2021 (UTC)[reply]

It might be worth mentioning that the efficiency is related to the ratio of the temerature across the heat pump, not the ratio of the inside and outside temperatures. This means you can improve efficiency by having larger but cooler radiators. -- Q Chris (talk) 10:10, 5 May 2021 (UTC)[reply]

t

"Sun poster" - today's featured picture

In today's featured picture, , I am confused by the layers.

The white triangle is presumably the centre of the sun, working out to the dark red triangle with the yellow/gold shell colouring. Then there is the orange circle (sphere) around that. But the yellow/gold shell doesn't appear to me to be concentric with the orange sphere. Indeed the curvature on the yellow/gold shell makes it seem bigger than the orange sphere. Am I not seeing something, or is the image flawed? -- SGBailey (talk) 09:40, 5 May 2021 (UTC)[reply]

Are you referring to the photosphere? It might help if you could point out which layer you are referring to, since they are all labeled. --OuroborosCobra (talk) 09:46, 5 May 2021 (UTC)[reply]

I agree with the OP that the diagram presents some interpretation confusion. I'm guessing (because it's not completely certain) that it's attempting to show a segment of the orange chromosphere peeled away to reveal the underlying yellow/gold photosphere. The depiction lacks any cues to help this depiction, such as an edge to the "cut" where the chromosphere was removed (presumably because, drawn to scale, the chromosphere lacks any significant depth), hence the possible confusion. (I could, of course, have misinterpreted the diagram completely, in which case it's much worse than I thought and not really a candidate as a featured picture.) Bazza (talk) 10:05, 5 May 2021 (UTC)[reply]

The yellow/gold shell is labelled Photosphere. The orange sphere is labelled Chromosphere. (I have no idea what "Temperature minimum" is pointing at and why it doesn't say "Minimum temperature". The "Transition region" appears to be the same as the Chromosphere.) -- SGBailey (talk) 10:16, 5 May 2021 (UTC)[reply]

Looking for stock image showing relative size of ISS orbit compared to Earth's diameter

I'm writing a school report about the "no gravity in space" fallacy, and I'm looking for an image which highlights the ISS's orbit relative to the size of the Earth. Where might I find something like that? --Puzzledvegetable^{Is it teatime already?} 22:39, 5 May 2021 (UTC)[reply]

There's a live tracker here with a few different views: [6]. The top left view shows the size of the orbit compared to the size of the Earth. --Amble (talk) 23:03, 5 May 2021 (UTC)[reply]

You'd be surprised how many times I've had to explain this. "Gravity at the altitude of the ISS is approximately 90% as strong as at Earth's surface, but objects in orbit are in a continuous state of freefall, resulting in an apparent state of weightlessness. This perceived weightlessness is disturbed by five separate effects..." See International Space Station. See vomit comet. 41.165.67.114 (talk) 06:45, 6 May 2021 (UTC)[reply]

May 6

Butterfly ID requested

Yesterday my father told me that when taking his afternoon walk in North San Jose/Milpitas, he saw a butterfly which he is sure was a swallowtail (he described its shape as "strictly triangular", which in my experience is only ever seen in swallowtails and very rarely in nymphalids), but rather small by swallowtail standards (he estimated its wingspan at about 2 inches, or as he said it was "about the size of a cabbagefly") and with a solid yellow coloration (like a brimstone butterfly) with no tiger stripes. I think it could have been an anise swallowtail (and told him as much) -- can anyone verify? 2601:646:8A01:B180:A990:90F3:3BA2:4FBB (talk) 01:38, 6 May 2021 (UTC)[reply]

@@ Line 191: / Line 191: @@
 I'm writing a school report about the "no gravity in space" fallacy, and I'm looking for an image which highlights the ISS's orbit relative to the size of the Earth. Where might I find something like that? --[[User:Puzzledvegetable|<u style="color:#0000ff"><span style="font-family:Century Gothic;color:#000000">Puzzledvegetable</span></u>]]<b><sup style="font-family:Century Gothic">[[User talk:Puzzledvegetable|Is it teatime already?]]</sup></b> 22:39, 5 May 2021 (UTC)
 :There's a live tracker here with a few different views: [https://heavens-above.com/orbit.aspx?satid=25544]. The top left view shows the size of the orbit compared to the size of the Earth. --[[User:Amble|Amble]] ([[User talk:Amble|talk]]) 23:03, 5 May 2021 (UTC)
+: You'd be surprised how many times I've had to explain this. "Gravity at the altitude of the ISS is approximately 90% as strong as at Earth's surface, but objects in orbit are in a continuous state of freefall, resulting in an apparent state of weightlessness. This perceived weightlessness is disturbed by five separate effects..." See [[International Space Station]]. See [[vomit comet]]. [[Special:Contributions/41.165.67.114|41.165.67.114]] ([[User talk:41.165.67.114|talk]]) 06:45, 6 May 2021 (UTC)
 = May 6 =