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July 20

A wind from 4 sides simultanously - possible?

Wind from 4 sides simultaneously - possible? I'm asking this question due to the reading in the bible, the first chapter of Job (1;18-19): "While he was still speaking, yet another messenger came and said, “Your sons and daughters were feasting and drinking wine at the oldest brother’s house, 19 when suddenly a mighty wind swept in from the desert and struck the four corners of the house. It collapsed on them and they are dead, and I am the only one who has escaped to tell you!”. Could it be any scientific explanation for this story?--ThePupil (talk) 02:36, 20 July 2021 (UTC)

The commentaries I've read suggest it would be a whirlwind. Given a "house" in that context it likely mostly just fabric and sticks, more like a tent, a strong swirling wind could easily cause it to collapse in on itself. DMacks (talk) 02:47, 20 July 2021 (UTC)

You must remember that any version of the Bible that comes to you in contemporary English is the result of numerous revisions and translations over the course of millennia, the result of which is a very great amount of idiomatic phrases arising out of anachronism and translational idiosyncrasy. (see Bible#Development, Biblical Canon, Authorship of the Bible, Bible translations, Bible translations into English, and Dating the Bible for just a summary of this immensely complicated subject). Further, often times these outmoded linguistic structures and the accreted peculiarities come to get codified somewhat because they are simply perceived, by way of the liturgical context in which they are learned, as the most appropriate and sanctified wording for the statements. As a consequence, you have every cause (in addition to the question of whether you are looking to take the actual events of the Bible to be considered apocryphal vs. factual) to not view the wording of biblical passages in their most literal possible interpretation here. I am no biblical scholar, so I cannot assist you with tracing backwards through versions of the work to arrive at the likely meteorolgical intent of "struck the four corners", but I rather expect you would find somewhere along that heritage that the phrase that was communicated was meant to convey a rather similar meaning to "shook it to its foundations" rather than "the wind came from four directions at once".

But to answer your query more directly: I know of no principled reason (owing to climatological principle or physical law governing air pressure) why four separate observable winds could not converge on one structure. Mind you, the idea of "a wind" as a unidirectional force pressure moving along a strict vector (as opposed to a rapid contoured change in pressure propagating in a non-uniform matter) is something an oversimplified mental construct. Unfortunately, I cannot supply you with a source which states expressly that it would be possible for four people standing in alignment with the corners of a structure to each perceive the wind to be coming from their cardinal direction, and in such amount that it causes said structure to collapse inward. The best I think you may get here is the observation that it does not seem to be contravened by any particular aspect of atmospheric dynamics. Snow ^{let's rap} 05:19, 20 July 2021 (UTC)

If the air comes in from different directions, converging on a small area, you get a pressure build-up that makes the accumulated air seek a way out. If there is no way out, the air will stop coming in when the local air pressure is equal to the wind pressure. The most obvious way out is in a vertical direction, the opposite of a downburst. But we could also have air flowing in from say 0°, 90°, 180° and 270°, with a horizontal outflow at 45°, 135°, 225° and 315°. This is unlikely to arise naturally, but you never know what a God will do who does not want to lose His bet with the Opponent.  --Lambiam 08:49, 20 July 2021 (UTC)

Similarly, a god (not being subject to the laws of physics) could make some of the air in the house disappear. This would create a partial vacuum which would be filled by wind from all directions and clearly could destroy the structure if the size of the effect was large enough. He could make it a sustained wind by continuing to destroy more air for some time. --184.147.181.169 (talk) 22:11, 20 July 2021 (UTC)

There is nothing in the Hebrew text suggesting the sudden wind coming from different directions. It is a ר֨וּחַ גְּדוֹלָ֜ה (rúakh gədoláh), a "big wind" (singular), coming מֵעֵ֣בֶר הַמִּדְבָּ֗ר (mê'êbér hamidbár) "across the desert". This does not sound like the description of a tornado to me. If we interpret this as a report on an actual event, keep in mind that the reporter is the sole survivor of the collapse of the house, managing to escape from the rubble, so this eye witness then apparently was attending the party inside and presumably had other things on their mind than delivering a accurate report of meteorological observations.  --Lambiam 08:32, 20 July 2021 (UTC)

I'd read "struck the four corners of the house" as "damaged the entire property" e.g not even one corner was left standing. The Living Bible even has: "engulfed the entire house so the roof fell in on them". The outcome is the same. Martinevans123 (talk) 09:03, 20 July 2021 (UTC)

• For a physics answer, wind is simply air motion. At any given location, wind speed can be represented as a vector (think: an arrow), and this vector can vary across space (think: a field of arrows). Some complicated equations govern how the wind vector can change across space and time, but there is nothing in theory that would prevent it from taking four different directions at four different positions, such as the corners of a house. Imagine, for instance, that the house is located in the center of a counterflow burner (which requires to blow only from two directions).

There are also boundary conditions that limit fluid motion; an extremely pedantic reading of "struck the four corners of the house" could be deemed impossible, because fluid cannot "strike" a solid boundary, because wind near an impermeable surface must be parallel to it. Frankly, if you are looking for physical impossibilities in the Bible, other passages are much better: the one that implies pi is 3, the ones used against heliocentrism, etc. Tigraan^{Click here for my talk page ("private" contact)} 12:48, 26 July 2021 (UTC)

July 21

Density trends in giant-planet moons

The Galilean moons get less dense in sequence as one gets away from Jupiter. This is usually explained by primordial heat from young Jupiter creating a strong radial temperature gradient that vapourised the volatiles especially on Io and Europa, IIRC. (Tidal heating probably helped too, I guess.)

However, the large satellites of Saturn and Uranus don't show any such trend. Is the explanation for this known yet? Double sharp (talk) 03:04, 21 July 2021 (UTC)

Which primordial moons are you considering large?Mimas, Enceladus, Tethys, Dione, Rhea, Titan, Hyperion, Iapetus, Miranda, Ariel, Umbriel, Titania and Oberon? Sagittarian Milky Way (talk) 05:13, 21 July 2021 (UTC)

The ones big enough that gravity should have collapsed them into solid bodies. So, the bodies you mentioned, minus Hyperion. Double sharp (talk) 05:28, 21 July 2021 (UTC)

There are so many variables, scientists can't even agree if Jupiter was once further than modern Neptune or closer than modern Mars. If you very spherical cowedly modeled it as an ideal gas of 1.3333 gram per mole particles that is not hotter in the middle, and the same joules per kg as the planetary gravitational binding energy and the orbits are same as today and the planets were twice as wide (which is the value given for Jupiter in its article) and they're as old as their parent planets' heat peaks then the planet effective surface temperature would be enormous (especially for Jupiter) and the number of square degrees of that in the sky would cause Europa and Mimas be roasted to incandescence even if they were of snow-like Bond albedo. But Mimas and especially Miranda would be less hot than Europa. And the heat wasn't dumped all at once of course and Jupiter had at least ~9 times more of it to get rid of than Saturn but not much more surface area to radiate it away. So I dunno, maybe Mimas wasn't roasted enough to cause the density trend. It's not implausible. Sagittarian Milky Way (talk) 19:46, 21 July 2021 (UTC)

Well, are there any known (stronger) trends for moons as they get farther from a planet? As this density is not a straightforward trend. Good topic! 67.165.185.178 (talk) 00:51, 22 July 2021 (UTC).

July 22

Radio waves and information

So in Layman's terms, what's the basis for how radio waves hold and transfer information? Like for smartphones and Internet. And can it be done for other wavelengths? If the answer is yes, I'm sure it won't be done for a lot due to health reasons, but if radio waves can transfer information, then what about wavelengths as light? Does that mean we can use a flashlight to transfer information as well? 67.165.185.178 (talk) 11:23, 22 July 2021 (UTC).

Light can be and is used quite effectively - see Fiber-optic cable. Wikignome Wintergreen^talk 13:24, 22 July 2021 (UTC)

Very simply you can switch the flashlight on and off and transmit a message via Morse code. That is obviously very slow but it is a form of amplitude modulation, which is one method of transmitting information by radio waves (AM radio). Another method is frequency modulation (FM radio), which is quite a bit harder to do with optical light. --Wrongfilter (talk) 13:43, 22 July 2021 (UTC)

• I'll just point out that Morse code transmission by flashing lights is not just a hypothetical example; it's been used importantly, principally at sea, as seen in the movie The Hunt for Red October, for example. --184.147.181.169 (talk) 00:16, 23 July 2021 (UTC)

In basic terms, waves can be combined and uncombined through a mathematical process called fourier series. The theoretical basis is that literally any arbitrary function can be represented by a superposition of multiple sine waves and that composing and decomposing such functions is done by simple addition of the waves. Information of any kind is embedded in a carrier wave (this is what you "tune" your radio to) and then some electronics in the receiver extracts the information by decomposing the waves from the carrier wave. On paper fourier series is messy, but it takes a relatively few, simple electronic components to perform the process physically and extract information from radio waves. --Jayron32 14:25, 22 July 2021 (UTC)

If you had a top-quality digital sound file of someone tapping the C4 key of a piano once (no pedal), and similar files for each note and you knew which parts of which files should be playing when, then could you also sum them into a graph of any arbitrary sound? i.e. metal or JFK speeches. Sagittarian Milky Way (talk) 16:20, 22 July 2021 (UTC)

Yes, you could. It needn't be a sine wave, you can compose any arbitrary function using any arbitrary wave form or set of arbitrary wave forms and you can also reverse the process (in theory, though it could get very mess in practice). I highly recommend 3blue1brown's videos on the Fourier series process, he takes it from a wide variety of angles (historical development via the heat equation, modeling fourier series using computer graphics, the equations behind it, etc. etc. etc.) If you want a good demonstration of how to create arbitrary plots using the Fourier series process, Here is a video where he uses the concepts of Fourier to tell a computer how to draw any arbitrary picture using nothing but harmonic functions (essentially sine functions). It's quite beautiful. This video is a bit lengthier, but in it he explains how he made those animations, and the math behind it. --Jayron32 16:30, 22 July 2021 (UTC)

edit: I linked to the wrong article. I have corrected my links above. It's the Fourier series I meant to link to, the Fourier transform which I originally cited is a related concept, but not as applicable here. --Jayron32 16:38, 22 July 2021 (UTC)

doi:10.1109/50.54508 is an example of FM of light near the visible range. DMacks (talk) 16:01, 22 July 2021 (UTC)

Okay 1 thing that radio waves cannot be used as light waves, is that light also behaves as particles (photons). So can't use light waves as radio waves since light will not go through a solid object. Can there be the equivalent of photons for radio waves? 67.165.185.178 (talk) 23:40, 22 July 2021 (UTC).

Radio wave radiation IS photons. And wave at same time (wave-particle duality) Sagittarian Milky Way (talk) 00:02, 23 July 2021 (UTC)

Okay, so photons at radio-wavelengths can go through solid objects? 67.165.185.178 (talk) 06:10, 23 July 2021 (UTC).

Light can go through glass bricks. Also AM radio stations emit wavelengths up to 555+ meters, good for quantum tunneling through and diffracting around anything opaque to them up to the size of buildings. Sagittarian Milky Way (talk) 06:31, 23 July 2021 (UTC)

Okay, I was gonna say, we don't see wavelengths at radio-frequency, this is the same for light-wavelengths? Meaning the only aspect we see of light is the photon-part of it. I wonder if light-wavelengths are the safest wavelengths radiation. 67.165.185.178 (talk) 06:42, 23 July 2021 (UTC).

Standard radio waves can be blocked by large objects. For example, when driving through a tunnel. ←Baseball Bugs ^{What's up, Doc?} carrots→ 06:44, 23 July 2021 (UTC)

Light can pass through a sheet of glass, which is quite solid. It can't pass through a wooden fence. Radio waves will pass through a wooden fence, but not through a metal wire mesh fence. Light has no trouble passing through that metal wire mesh fence (through the holes). It all comes down to wavelength, the scale of the object and its electrical properties. Both light and radio behave both as electromagnetic waves and as a stream of photons. For radio waves a wave description is almost always more useful. For light it's different. Detecting light is almost always done as a particle, but to describe refraction and reflection you need a wave description. Gamma rays are usually best described as a stream of photons. PiusImpavidus (talk) 08:26, 23 July 2021 (UTC)

Faraday cage for the metal fence thing, radio waves really don't like to pass through electrically conductive grids of holes smaller than their wavelength. Sagittarian Milky Way (talk) 15:52, 23 July 2021 (UTC)

Hence, as an illustrative example, the mesh in the glass doors of microwave ovens. {The poster formerly known as 87.81.230.195} 90.197.27.141 (talk) 14:22, 24 July 2021 (UTC)

Similarly, in some reinforced concrete buildings, you get really bad mobile phone reception, even if there's good reception outside, because the decimeter sized meshes of iron rods in the walls is close enough in scale to the microwave wavelengths used for mobile phone. – b_jonas 11:41, 27 July 2021 (UTC)

As for the original question, (1) we are already using significantly different frequencies of radio waves and microwaves for transferring information, from 30 kHz to 3 GHz. These propagate to different distances, partly because of how they disperse in the atmosphere, partly from how they bounce from the ground, surface of seas, and the ionosphere. Lower frequencies are generally used for longer distances but also lower communication bandwidth.

Near infrared (300 THz) is also used for communication, notably for handheld remote controls for home appliances. There is, notably, a gap between microwaves and near infrared which isn't used, because the atmosphere is too opaque to them. Anything higher frequency than visible light isn't generally used for communications as far as I know; instead some higher frequencies are used for medical imaging, passive astronomical obsercations, or analyzing crystal structure. – b_jonas 12:09, 27 July 2021 (UTC)

July 23

Conversion factor for torque

Repost as suggested from the Mathematics section.

Hi all, I'm trying to find the conversion factor (or constant) to work out the torque of some old engines and their gearboxes. Torque is given in Kilopondmetres (abbreviated in my sources as mkg or kpm), and power is stated in metric horsepower (PS). I realise that max. torque is often reached at lower revs than max. power.
For example:

• Torque (lb.ft) = 5,252 * power (hp) / speed (rpm)
• Torque (N.m) = 9.5488 * power (kW) / speed (rpm)
• Torque (kpm) = X * power (PS) / speed (rpm) — what is X? And if you're feeling charitable, why? I understand that 5252 ≃ 33,000 ÷ 2π.

Cheers, MinorProphet (talk) 02:15, 23 July 2021 (UTC)

GNU Units does this kind of thing automatically:

You have: metrichorsepower/rpm
You want: kpm
* 716.19724
/ 0.0013962634
That is, X=716.19724. 2601:648:8202:350:0:0:0:2B99 (talk) 03:27, 23 July 2021 (UTC)

Wow, that's fantastic! Thanks very much for your help. My PC's hard drive has been developing bad sectors and is likely to die soon, so installing another app wouldn't be good idea: otherwise I would have tried GNU Units. I hunted around a bit for the database/list of supported units, but couldn't find it. Best wishes, MinorProphet (talk) 04:22, 23 July 2021 (UTC)

Partially

Resolved

(MinorProphet (talk) 18:32, 23 July 2021 (UTC))

As an addendum, it is very easy to work out the torque/ angular velocity/ power relationship. For example the 5252 number is not magic, it is embedded in the definition of a hp. Greglocock (talk) 10:24, 23 July 2021 (UTC)

Thanks for your reply. As I said in my OP, I am aware of that: but what is 9.5488 in the definition of a KW, and 716.19724 as regards a metric horsepower (= 735.49875 W)? I imagine they are something divided by 2π, but what? You said "it is very easy to work out": for me it is very easy to speak French and German fluently, and Russian and Italian with a decent accent at least; but the mere mention of angular velocity and radians per second brings down the safety curtains of my mind. Cheers, >MinorProphet (talk) 15:39, 23 July 2021 (UTC)

1 minute = 60 s, and 1 PS = 75 kgf⋅m/s. The numeric value of 60 × 75 / (2π) is equal to 716.19724... I suspect that has something to do with it.  --Lambiam 19:55, 23 July 2021 (UTC)

Aah, genuine enlightenment from an unsuspected quarter. Top marks, go to the top of the class. Y MinorProphet (talk) 21:44, 23 July 2021 (UTC)

July 24

Submarine (anti) rainbow

Consider the usual model of a rainbow: What happens if we switch air and water? Namely, suppose the observer is under the water, surrounded by a cloud of small spherical gas bubbles, in a bright day. I imagine there can be refraction and light diffusion, maybe without reflection, so that a rainbow may be visible e.g. if the air bubbles are between the observer and the light source. But does something like that really occur? pma 15:10, 24 July 2021 (UTC)

A water-filled sphere in air works like a convex lens: a bundle of parallel incident light rays is made to converge. The reflecting other side works like a concave mirror, also promoting convergence. The combined effect is shown in the first figure at Rainbow § Explanation. An air-filled sphere in water works like a concave lens, so entering incident parallel light rays are made to diverge. The equation for $\beta _{\operatorname {max} }$ in the next subsection Rainbow § Mathematical derivation for solving $d\phi /d\beta =0$ does not produce a real solution. Also without internal reflection, I think the doubly diverging rays (a second round of divergence occurs on exit) cannot be expected to produce striking visual effects.  --Lambiam 20:25, 26 July 2021 (UTC)

Why can't NASA ascertain about total number of artificial satellite payloads around Earth?

This line from here says: In 1997 NASA estimated there were approximately 2,465 artificial satellite payloads orbiting the Earth and 6,216 pieces of space debris as tracked by the Goddard Space Flight Center. Why can't NASA easily add artificial satellite payloads if we have lists like this ? Rizosome (talk) 15:40, 24 July 2021 (UTC)

I do not understand why you think this incomplete list of communications satellite firsts can help NASA or anyone produce a list of all orbiting payloads. There is no easy way to tell if an orbiting object is a payload, artificial junk, or a (temporary) natural satellite, such as 2006 RH120 and 2020 CD3.  --Lambiam 23:11, 24 July 2021 (UTC)

Some sources to contextualize the scale of the problem for the OP, though it should be noted that they are not generally concerned with just enumerating payload launches but rather discussing the issue of orbital debris tracking and management holistically: [1], [2], [3], [4], [5], [6], [7], [8]. Snow ^{let's rap} 23:16, 24 July 2021 (UTC)

who buys all the 555?

It is said that over a billion are made every year, yet I've never ever seen a 555 "in the wild" and I've taken apart a thing or two. Aecho6Ee (talk) 17:34, 24 July 2021 (UTC)

They are not as common as they used to be, since it's often cheaper to do that stuff with digital parts now. The 555 is an analog timer that will often use a comparatively bulky external capacitor as part of an RC delay. That stuff is relatively expensive compared to a 3 cent microprocessor or just putting a timing function into some microprocessor that is already part of your circuit. 2601:648:8202:350:0:0:0:2B99 (talk) 05:06, 25 July 2021 (UTC)

Keep in mind that you wouldn't necessarily recognize them. The through-hole version they sell for hobbyists and legacy devices are easily spotted, but you can get them in much smaller packages.

Check out this lineup. The one on the left is a traditional looking 555, and the one on the far right looks like it could be accidentally inhaled. ApLundell (talk) 22:27, 25 July 2021 (UTC)

One of the characteristics of the traditional 555 was quite powerful output transistors for a thing that size. It could source something like 200mA if I remember right. I wonder if that tiny CSP one can do anything like that. 2601:648:8202:350:0:0:0:2B99 (talk) 02:12, 26 July 2021 (UTC)

July 25

Covid booster

If you're already vaccinated, is the idea of a booster that you get an additional shot of the same vaccine that you had before? Or are they tweaking the vaccines to handle the current virus variants? I'm trying to find out if I should (or can) bring my mom in for a 3rd shot. She had 2 shots of Moderna in January (due to her age), so she is outside the 6 month window that I've heard. Thanks. 2601:648:8202:350:0:0:0:2B99 (talk) 05:02, 25 July 2021 (UTC)

You shouldn't ask us, you should ask your doctor. ←Baseball Bugs ^{What's up, Doc?} carrots→ 05:41, 25 July 2021 (UTC)

Certainly ask your dcotor (or her doctor, rather) for advice about her. But I've been reading a lot of news about COVID vaccines and I haven't heard of any of them being tweaked to handle current variants. Rather, this is something that gets talked about as a possible future development. Also, in some places nobody is being allowed a third shot yet, to conserve the supply for first and second shots. So the doctor's advice may also depend on the rules where you are. --184.147.181.169 (talk) 05:50, 25 July 2021 (UTC)

I think there is not a vaccine shortage these days. There is consternation about having to throw out unused vaccines reaching expiration.[9] Main question was whether the vaccine boosters would be something new, which is a proper science question afaict. I have to call my mom's doctor anyway though, so I'll ask him about getting her another shot. He wasn't involved in getting her the initial shots though: that was done through the state web site, a big pain at the time. By the time I was eligible I was able to get a walk-in dose with no appointment and not much waiting. (I'm still in the 6 month period so not worrying about booster for now). 2601:648:8202:350:0:0:0:2B99 (talk) 08:06, 25 July 2021 (UTC)

As far as I can see (with all disclaimers regarding medical questions) this statement from the CDC and the FDA (8 July) is still valid. As I understand it, third shots are not even approved yet. --Wrongfilter (talk) 08:22, 25 July 2021 (UTC)

Vaccine supplies are still limited in large parts of the world. Even for the mRNA vaccines there are still many places which could handle them who are in big part limited by supplies. It's true there are a small number of countries like the US and Israel who have too much stock because they ordered and accepted a lot early on, but a significant chunk of their population is unwilling to get vaccinated, so they are now finding their vaccines are expiring. However if these countries start to compete for significant stocks again along with those who are getting close to them, this time for boosters, they will likely be mostly competing against countries where a significant chuck of their population even those particularly vulnerable ar3 unvaccinated. I don't think they will care even though it seems in the long term selfishness will harm them more, the only question is what level of evidence they will require before deciding to give booster shots. The US to their credit seem much more demanding of evidence than the UK. Yes I'm significantly more pessimistic than I was about 9 months ago that countries are going to screw us all with their selfishness. Nil Einne (talk) 13:27, 25 July 2021 (UTC)

Many countries even still have no access whatsoever to vaccine. It is conceivable that a deadly variant will emerge against which the current vaccines offer far too little protection before the world has reached global herd immunity so that the disease stops being a pandemic.  --Lambiam 08:25, 26 July 2021 (UTC)

• Right now, the French health authorities recommend a third dose for "severely immunosuppressed persons". (Link, in French.) I would hope they have some evidence to require that. Notice that "severely immunosuppressed" is not something random strangers can determine about your mother; this is different from "old".

We have an article about SARS-CoV-2 Delta variant. As explained at SARS-CoV-2_Delta_variant#Mutations, it does have some mutations on the spike protein that make it more transmissible. It cites this research article, which, in my limited understanding, would support a claim that the antibodies created by current vaccination practices are less efficient at targeting the mutated spike. It would therefore be plausible speculation that vaccine efficiency is lower for the Delta variant.

This is only speculation though. The way to know would be to run a proper trial: take in an unvaccinated, uncontaminated population of proper size, give half of them a placebo and half of them a vaccine, see the ratio of how many catch Delta in the vaccinated vs. placebo arms; compare with the trials for the other variants. Such a trial will probably never be done due to ethical concerns: placebo vs. treatment trials are justified when the treatment might be more harmful than helpful, but now the null hypothesis is "vaccination against Delta is just as efficient as against the previous variants", not "vaccination does nothing against Delta". A two doses vs. three doses trials could probably be run, though.

I am not aware of any study of the secondary effects of a third dose, which would absolutely be needed before recommending such a schedule to the general population. I am however confident that an uncontrolled trial of third- (and fourth-, fifth-...) -dose-taking will soon be run in France, so that really bad side effects will probably be uncovered by journalists. You need to be vaccinated or pay for a nose swab every two days to go to cinemas and other pleasant places (maybe the nose swabs are still free until next month but regardless it's a pain), and there is a sizeable antivax population with more money than sense; so, it is probably only a matter of time before entreprising individuals realize that you can take the vaccine under someone else's name and carte vitale (ID for the French health system) for payment. Requesting an actual ID which some places do is hardly sufficient to foil this attack: ID cards are valid for fifteen years (carte vitale, forever) so the photo is likely out of date, the person whose face you are supposed to check is masked, and (at my place) ID verification was done by a town hall clerk (who is not trained for police purposes - they only want to check your name off the booking list). Tigraan^{Click here for my talk page ("private" contact)} 12:29, 26 July 2021 (UTC)

Potassium-argon dating of amber

Can it be done? There is certainly some potassium in amber, the main question would be whether the argon is trapped in the amber over geological times, so that the ⁴⁰K/⁴⁰Ar ratio can be used for dating, or if it diffuses through amber too quickly. And also, how much initial atmospheric argon is dissolved in the tree resin which becomes amber. Icek~enwiki (talk) 12:11, 25 July 2021 (UTC)

This one is behind a paywall and with a 1969 publication date, is quite dated, but the relevant text reads "Radioactive isotope age determinations of amber are not feasible since most of the samples are too old for C** [sic] dating, and the presence of adequate amounts of potassium to utilize the potassium-argon method has not been demonstrated as yet" and also "infrared spectrophotometry has so far been most extensively used in analyzing amber". Other sources I found seem to suggest that some degree of carbon dating does get employed with amber samples these days, but despite casting my net wide and looking through a number of paleobotanical and paleontological reference works, I could not determine if potassium-argon dating is feasible with today's methodologies. Snow ^{let's rap} 14:15, 25 July 2021 (UTC)

July 26

Is soap harmful to most of cells of living things?

According to some health education videos such as [10], amphiphiles from the soap or detergents can break up the lipid bilayer envelope of viruses (e.g. coronavirus). On the other hand, cell membranes consist of lipid bilayers which can also be broken up by amphiphiles from the soap in my opinion.

So if someone has swallowed a lot the soap, what kind of damage will it lead to with regard to the cells in the body?

Do any amphiphiles exist in food? How about those molecules, if any, in food affect the cells and viruses in the body? - Justin545 (talk) 04:35, 26 July 2021 (UTC)

That video is not entirely accurate. In the case of most viruses it is not physically possible for soap molecules to get close enough to disrupt the lipid bilayer - this is more commonly observed in bacteria. And the amphiphiles (more typically called surfactants) certainly wouldn't form 'bubbles' (more typically called micelles) around the genetic material, as that's water-soluble. Any anti-viral benefits of soap would mostly be due to the physical removal of the virus, rather than the virus's destruction.

Regarding the harmful effects of ingested soap, our cells have an outer membrane of cellulose, which is highly resistant to oil, water and soap alike - this is why we can wash our hands without injuring ourselves. Any adverse health effects would be due to the soap's alkalinity, and chemical incompatibility with the digestive system, rather than due to its surfactant properties; the severity would depend whether you're talking about traditional soap, which is made from the reaction between fat and alkali, and has an alkaline pH around 9-10, or syndet bars, e.g. Dove, which have a more neutral pH. The former would be more harmful, but neither of them would do you any good.

Phospholipids are naturally-occurring surfactants which are the main component of cell membranes - for instance, lecithin, which is found in eggs, soy beans, and sunflower seeds, and is commonly used as a food additive. Vegetable-based emulsifiers, e.g. sorbitan oleate and glyceryl stearate, are also commonly used as food additives, and are known to be benign. Rhythdybiau (talk) 16:15, 26 July 2021 (UTC)

Our cells don't have an outer layer of cellulose; those are plant cells. Your skin specifically has an outer layer known as the stratum corneum which protects your skin from many harmful things, but not all of your cells have such a covering. --Jayron32 17:51, 26 July 2021 (UTC)

Good point, my mistake. Rhythdybiau (talk) 18:08, 26 July 2021 (UTC)

" it is not physically possible for soap molecules to get close enough to disrupt the lipid bilayer", what is the reason for that? Is it due to the outer layer of cellulose that separates soap molecules from the lipid bilayer? - Justin545 (talk) 03:34, 27 July 2021 (UTC)

Yep, I once thought that there should be something in food (such as surfactants lecithin and emulsifiers you have mentioned) that may also disrupt lipids. It makes me wonder why lipid bilayers of cells don't seem to be affected by surfactants and emulsifiers in food ... - Justin545 (talk) 04:12, 27 July 2021 (UTC)

The viral envelope that some viruses have, including the coronaviruses, is a lipid bilayer that is dissolved by soap, which then disrupts the next layer, the capsid, making whatever remains of the virus particle non-infectious.^[11][12][13] It is difficult to make a fully general statement of the effect of soap on living cells. For example, although not a good idea, you can wash a fertilized bird egg (which is a single cell) with mild soap and still expect it to hatch. Ingesting a considerable amount of soap can do severe damage to the lining of the digestive tract and is potentially lethal.^[14][15][16]  --Lambiam 17:09, 26 July 2021 (UTC)

"a lipid bilayer that is dissolved by soap, which then disrupts the next layer, the capsid", do you mean that soap can also disrupt the capsid of viruses? But capsids consist of protein, don't they? I thought soap mainly disrupts lipids ... - Justin545 (talk) 03:54, 27 July 2021 (UTC)

The capsid of coronaviruses does not have a convex shape and is not particularly strong, unlike that of some other viruses that don't have a lipid envelope protecting it. It is more like the skin of a long sausage of RNA tightly coiled up inside the envelope, as shown in the central image of three here. When a cell is infected by a coronavirus viroid, the entire nucleocapsid is delivered, wrapping and all. The wrapping disintegrates spontaneously once the lipid envelope is gone; otherwise the payload after delivery into an infected cell would not be unwrapped and remain harmless. Of course, the spike proteins are anchored in the lipid envelope, so even if the capsid is not disrupted the viroids lose their ability to infect cells when the envelope is destroyed.  --Lambiam 08:31, 27 July 2021 (UTC)