Wikipedia:Reference desk/Archives/Science/2021 May 2

= 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.  it is to be distinguished between muscle vs. muscles. --Askedonty (talk) 20:31, 2 May 2021 (UTC)

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)

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)


 * Bodybuilders use special training methods, see here. Count Iblis (talk) 09:56, 6 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)
 * 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)
 * 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)
 * 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)

The point being, though, that without being resonant, the light will not interact with matter, generally speaking. That is incorrect. Wear a white or black outfit on a sunny day and you can feel a significant difference in heat absorption, even though none of the molecules making up either outfit have excitation levels close to the frequencies of visible light. 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 is not true either. In the standard, Beer-Lambert law theory, the intensity of monochromatic light through a medium undergoes an exponential decrease with distance, with a characteristic length that depends on the wavelength; that length can take many intermediary values between zero (medium is totally opaque to that wavelength) and infinity (medium is totally transparent). (Related concept: optical depth, the ratio between an object's thickness and that characteristic length.) For instance, a glass of water looks transparent, but a large pool looks blue-ish. Per this article section (looks like a clear case of OR but it gives a plausible-looking graph), red light is absorbed after about 1m in water, while blue light can travel about 100m, so that if you look through a ~10m-sized water object the red light is gone but you can see the blue, so the bottom looks blue-ish. Tigraan Click here to contact me 12:36, 7 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).
 * A link rather straight forward: Endotelial cells line the interior surface of blood vessels, they are particularly smooth cells with low superficial reactivity just in order not to promote clot formation. Every damage to endotelial cells will stimulate clot formation and hence promote thrombosis (this is an usual mechanism at the origin of atherosclerose). 2003:F5:6F09:8D00:85F:AE48:72FC:BC78 (talk) 10:01, 7 May 2021 (UTC) Marco PB
 * "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)