Wikipedia:Reference desk/Archives/Science/2020 April 7

= April 7 =

Science
Is it debatable or a general agreement that science is discovering things that are already there? — Preceding unsigned comment added by 2001:8003:741B:500:64AD:7D03:A694:A55D (talk) 11:59, 7 April 2020 (UTC)
 * That's far too facile a statement to be either true or false. Science does a lot of complex things, and that is but one of them.  -- Jayron 32 12:22, 7 April 2020 (UTC)
 * "These are the only ones of which the news has come to Harvard, And there may be many others, but they haven't been discovered". Alansplodge (talk) 14:02, 7 April 2020 (UTC)
 * Agree with Jay. When scientists "discovered" titanium, they were discovering something already in nature. When scientists synthesized plutonium, they made something new that was not already there. Both things occur and are equally valid. --OuroborosCobra (talk) 16:06, 7 April 2020 (UTC)
 * The things we call "Science" also include meaning-making activities where we create models (often called in science "theories") that accurately represent in ways that can predict how reality will behave given a set of conditions. The act of making models and theories is at least as important, if not moreso, than simple acts of discovery and invention: Its the way we take a set of disparate discoveries and inventions and put them into a cohesive understanding of the world at a higher level.  -- Jayron 32 16:25, 7 April 2020 (UTC)
 * Indeed. I make heavy use of density functional theory in my own work, and its development was definitely worthy of its Nobel Prize. --OuroborosCobra (talk) 16:58, 7 April 2020 (UTC)
 * But can you say that DFT was "discovered", which is what the question was about? --Lambiam 20:03, 7 April 2020 (UTC)
 * No, you can't. DFT does not physically exist in the natural world. It is a mathematical model for solving the many-body problem when dealing with quantum mechanical systems, but it is just a model. These particles are not really interacting via local density approximations or generalized gradient approximations. If applying a hybrid DFT model, they certainly aren't interacting via Hartree Fock type mean field approximations, and in either case, are not obeying Born-Oppenheimer approximations. If it were what precisely occurred in nature, we would have a single perfect functional that we could apply to all systems, and we do not. These are models that, when applied properly, can be used to describe or make predictions about systems and their behaviors, but they are only models. --OuroborosCobra (talk) 19:03, 8 April 2020 (UTC)
 * See invention and contrast with discovery. The wheel, for example, is generally held to have been invented, not discovered, but its invention was basically science.--Shantavira|feed me 08:13, 8 April 2020 (UTC)
 * It is not uncommon to read that "Newton discovered gravity", even on academic sites.,, This use of the term discover has been criticized: "It is said that Newton discovered gravity when he saw an apple fall from a tree. This is a wrong statement. Newton did not discover gravity! Gravity was discovered long before Newton." "While it is sometimes stated that Isaac Newton 'discovered' gravity, this statement is not quite correct. It might be more accurate to say that the first monkey who fell out of a tree discovered gravity." "It must not be supposed that Newton 'discovered' gravity. Apples had been seen to fall before Newton's time, and the reason for their return to earth was correctly attributed to this mysterious force of attraction possessed by the earth, ..." The point is that the meaning of the term discover implies that the discovered entity existed already independent of the discovery. So when it is said that Johann Galle discovered Neptune in 1846, no one in their right mind will think that this planet did not exist prior to 1846. Used in this sense, scientists, like everyone else, only discover things that already exist. The verb is also used for facts that were previously unknown. Again, when it is said that Kepler discovered that the planetary orbits are ellipses, no one will (hopefully) claim that until then the planets had epicyclic motion. This tells us nothing about science, but only about the meaning of a word. --Lambiam 13:39, 9 April 2020 (UTC)

How does a respiratory tract infection spreads from the upper tract to the lungs?
How does a viral infection in the upper respiratory tract spread to the bronchial tubes, the bronchioles and the lungs? In other words how do the viruses move downward? Simply infecting the neighboring cells of the infected one seems too slow, I read that the average cell width is about 10 microns, even if the replication cycle took only 5 minutes, it would take 8 hours to advance one millimeter. But maybe they can reach cells much further away by brownian movement (diffusion).

Other possibilities I can think of are: transport by the air during inhalation (viruses have been detected in exhaled breath of people with respiratory infections, inhaled air could also pick up viruses and move them downward), spreading via the circulatory system (but in that case wouldn't all parts of the lower respiratory tract get infected at the same time?), or transported by the mucus (mucociliary clearance moves mucus upwards, but that's the net movement, doesn't mean it can't move in the opposite direction during inhalation.) I was thinking that if the virus only or mainly spreads via the "surface" of the respiratory tract (and not via the circulatory system), one could infect the nasal cavity of a person and insert some kind of physical barrier (stuffing it with cotton wads?) to reduce the rate at which it spreads, so the person develops immunity before the infection reaches the rest of the respiratory tract. But that's probably a naive idea... Prevalence 15:14, 7 April 2020 (UTC)


 * Inhalation of virus particles being shed by already infected tissue seems the most plausible pathway, unless the patient is severely immunocompromised – but then they may have worse problems than pneumonia. --Lambiam 19:59, 7 April 2020 (UTC)
 * They travel there alongside the air we breathe, but because the virions are extremely small (times smaller than blood cells, for example), it's more easy for them to get almost everywhere. Brandmeistertalk  09:54, 8 April 2020 (UTC)
 * I could't find any source discussing this topic, but then it must be my failure to think out search terms that our preferred search engine considers worthy of the effort. Anyway diffusion and/or transport along the bronchial liquid layer seems a possibility. Another is nevertheless transport by the blood: viruses that have a preference for some type of cells do recognise and dock on specific molecules on the cell surface. Sars-Cov2 is known to dock onto ACE2 molecules, which are mainly produced by lungs and kidney cells. 2003:F5:6F09:4800:5CE9:259F:4D96:AA02 (talk) 10:46, 8 April 2020 (UTC) Marco PB

How the coronavirus will die out.
The corona virus will die out by people's immune systems, right, the survivors. As for the deceased, their bodies get put into a coffin, 6 feet under, and that makes it hard for the coronavirus to spread from there, right? Bacteria have been able to be reactivated after being frozen for hundreds of years, so I suspect if someone dug into cemeteries hundreds of years later, for renovation, it's possible to reactivate the coronaviruses from the infected dead ones? 67.175.224.138 (talk) 18:49, 7 April 2020 (UTC).
 * What makes you think it will totally die out? ←Baseball Bugs What's up, Doc? carrots→ 18:59, 7 April 2020 (UTC)
 * It's possible, but more likely in places where the bodies are kept partially frozen. You may be interested in the work of Johan Hultin. See this as well. Also, Bugs may be correct: there is no guarantee that this will ever die out. It may become a background disease like most of the other coronaviruses. Matt Deres (talk) 19:04, 7 April 2020 (UTC)


 * Wikipedia has an article on paleopathology, a field of interdisciplinary science that is of interest to archaeologists, anthropologists, evolutionary biologists, and medical researchers.
 * Whether this specific virus - or any other infectious agent - could hypothetically remain harmful after a long time in ... "storage " ... is kind of a complicated question. I don't think we can really answer it completely for all cases - but we can point out some examples.  Some virus particles become inactive after just a few hours - and others can remain dormant-but-hazardous for weeks; some infectious agents have no meaningful half-life and are expected to remain hazardous for as far out as we can reasonably predict into the future; some virus activity depends on the kind of environment the particles are exposed to; so there's no universal answer.
 * The Federal Select Agent Program - the very same one through which you can order your free government-issued SARS-associated coronavirus clones and complete genomes sampled from several dozen isolates - provides guidance and regulatory information about best-practices and mandatory procedures to render a Select Agent (like a virus or other biological hazard) "inactive," which is a fancy term that almost means "not infectious," but technically doesn't. Directly quoting: "FSAP acknowledges that 100% inactivation of material is not possible in both a mathematical and practical sense."  As a physicist, I can't even begin to tell you how happy it makes to see precision of terminology applied in the wet-sciences!
 * This lovely field-guide to Safety and Health in Archaeology, published by my local university (and repository of information at the host institution for the numerical-modeling epicenter of the present epidemic-of-national-importance), ranks archaeological exposure to infectious agents in the Pacific Northwest as lower-risk than the hazards of poisonous plants, blisters, and bee-stings. That is categorically different than saying there's no risk - but hey! - who pays any attention to the subtlety of quantitative and qualitative risk management these days?
 * Nimur (talk) 19:29, 7 April 2020 (UTC)
 * You might hope to find enough traces of RNA to identify the virus, but no intact virions that could be "reactivated". A viral capsid is stable enough for the virus to transmit and infect a host, but not that stable. They need to be somewhat unstable because they have to break up for the genetic material to enter a host cell. --Lambiam 19:53, 7 April 2020 (UTC)
 * What I just wrote is not necessarily true. Reportedly,, scientists have succesfully revived an amoeba-infecting virus trapped in ancient permafrost. --Lambiam 20:21, 7 April 2020 (UTC)
 * Quite. There are counter-examples and counter-counter-examples and counter-counter-counter-examples...; to summarize, "it depends."  Nimur (talk) 20:48, 7 April 2020 (UTC)
 * Hence the advice to wash hands after touching counters. ←Baseball Bugs What's up, Doc? carrots→ 21:02, 7 April 2020 (UTC)
 * Yes, at lower temperatures, things are preserved longer. Viruses are quite diverse so it's hard to make sweeping generalizations, but a lot of viruses are pretty fragile. Viruses aren't free-living organisms, and every trait has evolutionary tradeoffs; viruses will often optimize for easy transmission more than other things like long stability as free viruses. The majority of viruses are enveloped and are destroyed if the envelope is disrupted. Bacteria that persist for very long times often do so by forming endospores, which are inert but very resilient; examples include the bacteria that cause anthrax and tetanus as well as many fellow members of their genuses, Bacillus and Clostridium. --47.146.63.87 (talk) 03:36, 8 April 2020 (UTC)
 * AHEM. genuses genera--Khajidha (talk) 20:06, 10 April 2020 (UTC)
 * Viruses can be made ab initio in the lab, see here:
 * "Eradicating smallpox, one of the deadliest diseases in history, took humanity decades and cost billions of dollars. Bringing the scourge back would probably take a small scientific team with little specialized knowledge half a year and cost about $100,000." Count Iblis (talk) 20:05, 7 April 2020 (UTC)
 * (Convenience link: ab initio.) Although currently there's substantial herd immunity as many people who received the smallpox vaccine are living. (It's still given to some people.) Might be nice to invest more resources into developing antivirals though. --47.146.63.87 (talk) 03:36, 8 April 2020 (UTC)


 * Further to the "Johan Hultin" article linked above, see The Deadliest Flu: The Complete Story of the Discovery and Reconstruction of the 1918 Pandemic Virus which was reconstructed using material found in Inuit graves in a remote Alaskan settlement. Alansplodge (talk) 10:48, 8 April 2020 (UTC)


 * “Moore’s Law of Mad Science: Every eighteen months, the minimum IQ necessary to destroy the world drops by one point.” (Eliezer Yudkowsky, who once slept on my sofa; EVERYTHING IS CONNECTED.) Compare the title of Bruce Schneier's latest book, Click Here to Kill Everybody. —Tamfang (talk) 03:50, 14 April 2020 (UTC)
 * That is Manifestly clear. ←Baseball Bugs What's up, Doc? carrots→ 05:22, 14 April 2020 (UTC)