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April 27

E2 (in real life)

A few questions about the arguably most famous switch engine of all (completely out of proportion to its actual role in rail transport), the LB&SCR E2 Class: (1) How far could it go before it had to take on water? (2) How far could it go before it had to take on coal? (3) What was its top speed under its own power (on the level with a light train)? And (4) if it was being dragged by a faster train (like in "Thomas Gets Tricked"), or pushed downhill by a heavy unbraked freight train (like in "Trouble for Thomas"), how fast could it go without derailing? 2601:646:8A01:B180:CDB1:68B7:A1BD:8384 (talk) 05:53, 27 April 2021 (UTC)

There's not a lot of technical detail in our articles, but I can make a few educated guesses. The E2 used the same boiler and cylinders as the I2, so it would have about the same coal and water consumption per unit of time. It had smaller wheels, so would do so at lower speed, hauling a heavier train. The I2 was in turn a stretched version of the I1 (few other modifications), with the same, undersized firebox. The same cylinders and pressure mean the same peak power, the same firebox means the same sustained power, larger boiler means it could hold peak power for a bit longer. The boiler acts as a buffer, where energy from the fire is temporarily stored. The small firebox means it had low performance, but also low consumption of water and coal.

The I1 and I2 where meant for suburban passenger trains. Typically, one would design the water tanks large enough to run from one end of the line to the other, which would be less than an hour on these suburban lines. Water capacity of the E2 was about half the capacity of the I2, so, when working hard, I guess it could consume all its water in half an hour. But most of the time it wouldn't be working hard. Real-life driving would be with frequent stops and quick acceleration to about 40 km/h, but at constant speed the water supply would last much longer.

In a typical steam locomotive of that age, 1 ton of coal could make 7 tons of steam. The E2 carried 5 tons of water and 2.5 tons of coal, so its coal supply would last 3.5 times as long as its water supply.

At high speed, steam locomotives suffer from large, unbalanced reciprocating masses. This causes the locomotive to flex, bounce on its springs and ultimately jump off the track. The effect mostly depends on the rpm of the driving wheels, not on speed directly (which is why express locos had such large driving wheels). Further, at high rpm it gets harder to get the steam in and out of the cylinders quickly enough without excessive loss of pressure, limiting power. Anything over 5 revolutions per second would be called fast, some locomotives reached around 10 revolutions per second. On an E2, 5 revolutions per second means 78 km/h. I don't know how well balanced it was, but as it was designed for low speed, probably not very well. PiusImpavidus (talk) 12:02, 27 April 2021 (UTC)

On second thought, it's possible the water tanks of the I2 were oversized, for some extra reserve. In that case it could run for longer before the water supply was exhausted. Without details like actual water/coal consumption or at least grate area it's impossble to say. PiusImpavidus (talk) 08:36, 28 April 2021 (UTC)

About Covid 19 and Covishield vaccine

Q1, I am a bit confused regarding 14 day quarantine/isolation. If someone comes in contact with a positive patient then he is(/was earlier) advised for 14 day quarantine to check if he developes covid symptoms as 14 days is believed to be max. incubation period. If no symptoms after 14 days then roam freely(with mask) But, what about one who is positive. Is there a guideline that if you are home quarantined for being positive then what?? Does the person's quarantine ends automatically after 14 days or should he get tested again for negative report ? Where am I thinking wrong? -- Parnaval (talk) 06:07, 27 April 2021 (UTC)

It varies but usually until two successive test are negative. Ruslik_Zero 12:00, 27 April 2021 (UTC)

Q2, In India there is vaccine named Covishield. I am searching for guideline about what to do if we currently have covid or have just recovered. Should there be a time delay (of, say, a month or a week) before we take a 1st or 2nd dose. Not for personal advice, just because I am curious -- Parnaval (talk) 06:07, 27 April 2021 (UTC)

For those who have had COVID-19 vaccination against it is not indicated at least for 6 months after it. Ruslik_Zero 11:59, 27 April 2021 (UTC)

@Ruslik0: Thanks for answer 1, but is the protocol of two negatives really followed. And answer 2 is not clear to me. Can you elaborate. I think you misunderstood question 2. I was asking about potential negative effects(if any) of the vaccine if taken during or just after recovering from infection -- Parnaval (talk) 16:45, 27 April 2021 (UTC)

There will be no negative effects. Ruslik_Zero 16:54, 27 April 2021 (UTC)

We should be careful about giving medical advice this way, even if it isn't "personal advice," without sources. I personally wouldn't have guessed that vaccines could give someone blood clots, but in a very very small percentage of individuals, they can. I don't think we should say "there will be no negative effects" of taking the vaccine just after recovering from infection without some source to back that up. Even if the incidence is low, maybe that causes some sort of autoimmune response, especially in compromised individuals. Again, I'm not saying it does, just that we should probably provide sources before saying, unequivocally, that there will be no negative effects. --OuroborosCobra (talk) 18:39, 27 April 2021 (UTC)

@OuroborosCobra: That blood clot problem is very rare. But I am asking about a bigger risk. I mean, there has to be a guideline about taking(or not) vaccine during or after covid infection because on any day, there are millions of people who are positive and as everyone is pushing on more vaccination what about those who are infected, should the people be stopped -- Parnaval (talk) 09:06, 28 April 2021 (UTC)

Of the millions who have taken a vaccination, many thousands must have been asymptomatic or presymptomatic carriers. Nothing special regarding this contingency has been reported. There is no advice to get tested prior to being vaccinated, which there would be if there was a known associated risk. Of course, people who are symptomatic or known to be carriers should not visit a vaccination site but stay home.  --Lambiam 09:32, 28 April 2021 (UTC)

I actually meant that there will be no negative effects specifically related to the previous COVID-19 disease - the question was about them. At least nothing known about them and as has been already noted many millions people, who had had COVID-19, have been already vaccinated. Ruslik_Zero 20:04, 28 April 2021 (UTC)

Movements through switches

What are the typical speed limits for the following types of railroad switches: (1) variable switch or spring/weighted switch; (2) double slip or single slip switch; (3) outside slip switch; (4) scissors crossover; (5) three-way switch; (6) interlaced turnout; (7) wye switch; (8) dual-gauge switch; (9) dual-gauge swish (spelling is correct); and (10) switch diamond? 2601:646:8A01:B180:CDB1:68B7:A1BD:8384 (talk) 06:22, 27 April 2021 (UTC)

As I understand it, it is not so much the type of switch as the curvature of the track. On a straight track there is no need for a limit. The article you linked to discusses this in some detail, but says "As a general rule, the smaller the crossing angle of a turnout, the higher the turnout speed." See Railroad_switch#Turnout_speeds.--Shantavira|^{feed me} 09:19, 27 April 2021 (UTC)

I was aware that for standard switches, the curvature of the track is the limiting factor -- but I was wondering, maybe for these unusual types, there could be additional factors which further limit the maximum speed of the train (for example, an increased danger of splitting the switch at higher speeds)? 2601:646:8A01:B180:28A4:780E:CE56:DB62 (talk) 11:52, 27 April 2021 (UTC)

Types 1, 2, 3, 4, 5, 6, 8 and 9 are usually found in yards, where speed is already limited to about 40 km/h. All switches would normally have the same radius of curvature and speed limit. It doesn't depend on the type. An outside slip has a longer arc and therefore larger radius of curvature at the same angle than an inside slip, so could have a higher speed limit, but this is not practical as speed is already limited by other nearby switches. Outside slips make some sense if the angle is a bit courser than normal. On wye switches practices vary between countries. In Germany they're only common in yards, where speed is low anyway, but in the neighbouring Netherlands they're frequently used away from stations, where the speed limit is much higher (120 km/h). The wye switches are used there because they allow a higher speed limit. The switch diamond tends to have a high speed limit, as at low speeds a non-switching diamond is usually sufficient as one can arrange the angle to be course enough. PiusImpavidus (talk) 12:36, 27 April 2021 (UTC)

J70 steam tram

Did the J70 steam tram have sandboxes? If not, how did they deal with slippery tracks? 2601:646:8A01:B180:28A4:780E:CE56:DB62 (talk) 11:55, 27 April 2021 (UTC)

I don't know where you got the idea that a Sandbox (locomotive) is required to deal with slippery tracks. It is far more convenient, but older locomotives sometimes used a man with a shovel to sand the tracks (often needed only on startup and on steep grades). On some newer locomotives the Wheel slide protection is good enough that sand is rarely needed, and in some places a special train applies Sandite. --Guy Macon (talk) 12:52, 27 April 2021 (UTC)

As far as being required on steep grades/inclines, goes, the lines for which these locomotives were designed and were later used didn't (to my partial personal knowledge) have any to speak of. {The poster formerly known as 87.81.230.195} 90.200.135.95 (talk) 11:34, 28 April 2021 (UTC)

Why do humans feel their skin crawlwhen they saw disgusting images?

Why do humans feel their skin crawl when they saw disgusting images? Is there any reason for this? There is also a idiom exist in English language. Rizosome (talk) 13:05, 27 April 2021 (UTC)

See Goose bumps. ←Baseball Bugs ^{What's up, Doc?} carrots→ 13:10, 27 April 2021 (UTC)

We also say "It made my skin crawl", whatever that is supposed to feel like. Richard Avery (talk) 14:53, 27 April 2021 (UTC)

April 28

Does Cryoprecipitate have platelets?

Does cryoprecipitate contain platelets? --ThePupil (talk) 16:55, 28 April 2021 (UTC)

The article links to Blood plasma, which you may find helpful. ←Baseball Bugs ^{What's up, Doc?} carrots→ 17:19, 28 April 2021 (UTC)

The article Blood plasma makes clear that blood plasma does not contain blood cells, but is not explicit about the plasma not containing platelets – which are not regular cells, as they have no nucleus. The point is that plasma is pure liquid (or almost pure – there is no such thing as 100% pure plasma). It is mostly water; any other substances (such as salts and proteins) are dissolved in the water. Platelets do not dissolve in water; they are separated from the plasma in the preparation process.  --Lambiam 09:32, 29 April 2021 (UTC)

The lack of a nucleus doesn't not make something a cell. In most mammals, red blood cells lack a nucleus. Platelets also lack many of the other structures and functions of cells as well, being basically cell fragments. However, the line is rather arbitrary, as their other name (thrombocytes) literally means "clotting cell". Langauge and categorization are not always logical or consistent. <shrug>. --Jayron32 01:47, 30 April 2021 (UTC)

What part of Muon G2 results are not explained by current theories ?

Physicists discover Muon G2 results are not explained by current theories. source. So what part of Muon G2 results are not explained by current theories ? Rizosome (talk) 17:42, 28 April 2021 (UTC)

This video explains it better than I could. In a nutshell, the experiment measures how much the muon is disturbed by other particles. Each other particle a muon interacts with will alter its behavior by a measurable amount; once you account for every known particle in the standard model, there's a tiny little bit of motion that is unaccounted for. That little tiny bit of leftover disturbance can't be explained by any known part of physics, so if it is correct, then it means there is some part of physics that the Standard Model doesn't contain. You really should watch that video if you want more details, though. --Jayron32 17:47, 28 April 2021 (UTC)

The "g-2" in the name of the Muon g-2 experiment is read as "gee minus 2", where the "g-factor" is the magnetic dipole moment of the muon. In quantum field theory you treat this as a kind of series expansion (where subsequent terms contain coupling constants raised to higher and higher exponents). The first term is exactly 2. If you subtract this out, you get the anomalous magnetic dipole moment g-2. The question is whether the measured value of g-2 matches the sum of the higher terms in the series expansion given the fields and coupling constants in the standard model. Unfortunately, the standard model includes QCD, so the series expansion includes hadronic terms that can't be calculated in perturbation theory. Getting values for those terms requires a very difficult mix of theory and empirical measurement from other experiments. About 20 years ago when the Brookhaven muon g-2 experiment had a similar result, it turned out that there had been an error in these hadronic terms on the "theory" side (the same sign flip error made independently by two groups of theorists). If the new experimental results are correct, it could be that there are new terms in the series expansion (new particles and fields), or that there are corrections to be made in how the standard model terms are calculated. --Amble (talk) 20:39, 28 April 2021 (UTC)

@Amble: Our article Muon g−2 makes no mention of inadvertently flipped signs. It seems (to me) interesting enough to mention this. Do you have sources? (There is a mention of physicists at CERN having to recalculate their theoretical model because of a discrepancy, which is not unambiguously clear about the cause of the discrepancy – theoretical error, or calculation with insufficient precision.)  --Lambiam 09:09, 29 April 2021 (UTC)

@Lambiam: There’s a good writeup from 2004 by one of the g-2 collaborators here: [1]. The part of the story I was talking about starts at the end of p. 32 and continues at the top of p. 33. A similar saga played out several times where the g-2 experimenters would publish a tighter measurement about 3 sigma from the SM prediction, and each time the best SM prediction would hop to 1-2 sigma from the experimental result. It would be great to add some of this to our articles. —-Amble (talk) 11:46, 29 April 2021 (UTC)

Thanks, maybe later; this requires careful reading, and I'm facing an imminent deadline absorbing my attention.  --Lambiam 13:46, 29 April 2021 (UTC)

See also Sec. 4.2.4 in the very recent, very comprehensive, very long review paper here: [2] --Amble (talk) 16:53, 29 April 2021 (UTC)

True to form, the snippet you mentioned about recalculating the theory during the CERN days isn't either of the Brookhaven-era (early 2000's) cases I had in mind, but yet another time that the same basic story played out. This one was back in the 1960's or 1970's. --Amble (talk) 17:28, 29 April 2021 (UTC)

It's shocking that we don't have anything at all on the infamous 17-keV neutrino [3]. Anybody who's looking for a new topic that needs an article could write a great one about that saga. --Amble (talk) 17:53, 29 April 2021 (UTC)

@Amble: It's looks like everybody posting their edits in too technical manner. I want simple English edits. Rizosome (talk) 17:12, 30 April 2021 (UTC)

There is a kind of particle called a muon. We make lots of muons. We put the muons close to a big magnet. The magnet makes the muons turn. Every kind of particle helps the magnet turn the muons. Photons help the magnet turn the muons. Electrons help the magnet turn the muons. Protons and neutrons help the magnet turn the muons. Maybe there are other kinds of particles that we don't know about. The new particles might help the magnet turn the muons. We watch the muons turn because we want to find out about new particles. A lot of muons went by the magnet. We measured how much the muons turned. They turned a little more than we expected. Maybe there is a new particle! --Amble (talk) 18:12, 30 April 2021 (UTC)

Didn't I say basically exactly that, in that level of English, in the first answer? --Jayron32 18:44, 30 April 2021 (UTC)

Your answer seems clear (and entirely correct) to me! I'm not really sure what OP is looking for, so I can only say what I was aiming to add. My first answer was mainly to explain why the theory value has been a moving target. After the subsequent request for simple English, I wanted to convey what physical quantity is measured, without using words like theory, standard model, interact, disturb, and field. --Amble (talk) 19:03, 30 April 2021 (UTC)

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)

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)

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. --Jayron32 18:05, 30 April 2021 (UTC)

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)

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)

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)

In a hospital context:-

• BBC Radio - Coronavirus: 'Proning' technique saved my wife's life
• BBC News - 'I went from spreadsheets to proning Covid patients'
• Reuters - WHO issues new clinical advice on treating COVID-19 patients
• Thorax (British Medical Journal) - Awake prone positioning in COVID-19

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

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

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) Was that at all necessary or appropriate? --OuroborosCobra (talk) 05:04, 2 May 2021 (UTC) It contradicts the premise. ←Baseball Bugs What's up, Doc? carrots→ 09:28, 2 May 2021 (UTC) 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) 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)

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)

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)

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)

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)

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)

@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)

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

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)

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)

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)

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)

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)

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)

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)

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)

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)

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)

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)

• 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)

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)

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)

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)