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September 14

How Do Small Changes In Composition Change The Properties Of Molecules And Atoms So Much?

Please do been helping me understand. ~~Alex Salazar 13:31, 14 September 2023 (UTC)

Can you give an example? It’s hard to know what constitutes a “small” change in composition in your mind. Also, it isn’t even always true. Sodium hydroxide and potassium hydroxide differ in 1/3rd of their atoms, and have a 40% difference in mass, but in most applications are practically interchangeable as long as the same number of moles of the salts are used. —OuroborosCobra (talk) 14:16, 14 September 2023 (UTC)

No Need for Been Attack. I will See You if I may Figure Out How This Goes. For Me I Been Suppose There Is A Duality Of Arsenic Acid And Carboxygenic Gas. ~~Alex Salazar 50.237.188.108 (talk) 14:43, 14 September 2023 (UTC)

That's a good question and one which those who design drugs and other commercially-important chemicals would love to know the full answer to! The nearest article on this subject may be Quantitative structure–activity relationship but is a bit technical for non-specialists. Roughly speaking, for drugs and pesticides the analogy of the lock and key model is usually quoted. Mike Turnbull (talk) 15:02, 14 September 2023 (UTC)

I do been wanting to tell you thank you for the citation of me, Mike Turnbull. 50.237.188.108 (talk) 15:54, 14 September 2023 (UTC)

I'm going to disagree a little bit here. That analogy works well for larger molecules (large organic compounds or full on macromolecules, like proteins), but it isn't always so easily apparent for smaller molecules or even small active sites within proteins or enzymes. The example that Alex is talking about, between what is mostly carbon dioxide and arsenic acid, that's not at all what I would consider a "small" composition change, since we have a huge elemental difference, geometry difference, etc., but what if we made it arsenic acid vs phosphoric acid? They are structurally very similar, their elemental composition is identical except for the core atom (arsenic vs phosphorous), but in terms of overall properties, this doesn't seem to have much of an impact. Their pKas are nearly identical, their melting points are fairly close, etc. However, one is extremely toxic, and the other (in moderation of course) is fairly benign and not an uncommon intentional food additive, such as in carbonated beverages. The difference is that arsenic is a metalloid, and phosphorous is strictly a non-metal. Metals and metalloids tend to love to bind to sulfur (some nice inorganic chemistry reasons that I won't get into, but look to electron configurations, d-orbitals, in other words, electron wavefunctions and quantum stuff that isn't apparent at all in a "lock and key model."). It's similarity to phosphorous allows it to bind in place of phosphoric acid in some important areas not related to sulfur, and its binding to sulfur (such as thiols in many amino acids) completely disrupts the function of vital enzymes. Put that together, and the citric acid cycle quickly breaks down, you stop making ATP, and you die. --OuroborosCobra (talk) 14:27, 15 September 2023 (UTC)

September 17

“Kilo press”

In the news today; apparently some kind of equipment used in drug manufacture kilo press. No article on it on WP, nor does it google well. Could someone write it? 2603:7000:2940:21:40F6:C37B:9009:3853 (talk) 05:38, 17 September 2023 (UTC)

It's a hydraulic press used to make the compressed bricks of drugs. Here's an FBI pic of one. I don't think there is even a Wikipedia article on illegal drug packaging in general. Abductive (reasoning) 09:10, 17 September 2023 (UTC)

For information: The fox59 link may not be usable outside the USA. In the UK I see "This content is not available in your country/region" and the tab says "Access Restricted". Martin of Sheffield (talk) 09:18, 17 September 2023 (UTC)

It is a clipping of kilogram press, a term used in releases by the judicial system^[1][2][3] and police departments^[4][5] and in news reports.^[6][7][8][9] Since the pressure exerted by one kilogram is puny, the name comes perhaps from the fact that these presses can compress a quantity of one kilogram into a solid brick, as advertized here.  --Lambiam 11:21, 17 September 2023 (UTC)

Wheel load 40 - 50 t/m

This page[10], under section "Crane Sizes & Technical Specifications" lists various Wheel loads from from 30 to "50 t/m".

What's "t/m"?

I think it might be metric ton per meter, but I'm not sure. I googled around and found the Axle load article which says:

The standard rail weight for British railways is now 113 lb/​yd (56.1 kg/m).

I expected a container crane to have a far higher load than a train, but not 900 times more. Satoshit1 (talk) 06:58, 17 September 2023 (UTC)

113 lb/yd is the weight of the rail, not the weight of the train. Quite literally a yard of 113 lb rail weighs 113 lb. See Rail profile#Rail weights and sizes. The axle load article mentions that British practice limits locomotives to 22.5 tonnes per axle whereas the Australian limit is 42 tonnes per axle. Martin of Sheffield (talk) 08:17, 17 September 2023 (UTC)

These port cranes run on rails using groups of wheels. All wheels in a group are connected by balance beams, to make sure all wheels are equally loaded. Within such a group, 30 to 50 tonnes per metre sounds plausible. That number determines the strength of the foundation under the tracks.

For trains, standard axle loads and metre loads have been defined. In Europe, there's a letter for the weight per axle and a number for the weight per metre; German wiki has a nice table: w:de:Streckenklasse. The standard in my country (Netherlands) is that all routes support at least 20 tonnes per axle and 6.4 tonnes per metre (class C2) up to line speed, and most also support 22.5 tonnes per axle and 8 tonnes per metre (class D4) up to 80 or 100 km/h. That's why bulk goods trains are slower than passenger or container trains and can't use some lines during the day. High axle load combined with high speed greatly increases track maintenance, a somewhat unexpected problem when faster trains were introduced in the 1960s and '70s. American and Australian trains are much heavier than European trains, but also much slower for this and other reasons. PiusImpavidus (talk) 09:56, 17 September 2023 (UTC)

How is it possible for a man to become pregnant?

I’ve seen a few people refer to pregnancy in men and I’m wondering how this happens? My understanding of physiology is that a man would not have the uterus required to gestate a fetus. There are also issues regarding gametes (males obviously lacking ova). These are probably the top two things limiting my understanding of how a man could become pregnant. Can anyone explain it to me? Codasoat (talk) 23:08, 17 September 2023 (UTC)

Where did you see this? ←Baseball Bugs ^{What's up, Doc?} carrots→ 23:59, 17 September 2023 (UTC)

Does male pregnancy help? Matt Deres (talk) 00:43, 18 September 2023 (UTC)

Transgender pregnancy is the most relevant article.-gadfium 01:07, 18 September 2023 (UTC)

This just in: Man tests positive on pregnancy test, leaves doctor astonished. Shantavira|^{feed me} 12:07, 18 September 2023 (UTC)

That is a side effect of a metastasised tumour that had invaded his liver. Although the hormones were those usually associated with pregnancy the man was not pregnant. Martin of Sheffield (talk) 14:16, 18 September 2023 (UTC)

As suggested, transgender pregnancy is pertinent. It is referred to in press as a "pregnant man" using self-identification of gender as the definition of "man." It is not "pregnant male" using biological definition of sex at birth. It is likely that this concept if very old as any biological female in history who became pregnant could have self-identified as a man to become the first pregnant man. 12.116.29.106 (talk) 12:56, 19 September 2023 (UTC)

September 18

Dark matter attraction and Galaxy size

Let us consider 2 spheres (or disk as for Galaxy) made up of the same large number of n mass elements, therefore of the same overall mass, but of radius r and 2r, a little on the principle of galaxies in space. What is the difference in the forces of gravity applied to an object located at r/2 for the 2 spheres? I suppose that on the same principle as for galaxies and dark matter, the centripetal attraction for such an object is greater for the small sphere. Malypaet (talk) 08:58, 18 September 2023 (UTC)

If the mass is spherically symmetric, then the attraction is due to the sphere inside the radius. So what happens will depend on the mass distribution, but likely the smaller galaxy will have higher gravity at a fixed distance. In general relativity you will also have to consider gravitoelectromagnetism which will be much greater for the compact arrangement of spinning mass. Doesn't matter if matter is dark, dim or bright. Graeme Bartlett (talk) 09:57, 18 September 2023 (UTC)

See shell theorem. Modocc (talk) 02:42, 20 September 2023 (UTC)

"Normal" basic compounds and extreme of proton affinity

1* What is the most basic chemical compound whose molecules or ionic-molecules are overall e-neutral known? (So obviously this criteria excludes the elusive anionic species such as diethynylbenzene(2-) isomers and lithium monoxide(-)) "Known" means that the candidate chemical species must have been synthesized and detected by some means. I gave a special attention to this problem since these basic chemical species would be reasonably isolated as "normal" substances on certain inert surfaces, not just only exist as diluted gas. 2* What is the most basic inorganic/organic compound whose molecules or ionic-molecules are overall e-neutral known? (If the chemical compound in the first question turns out to be inorganic, then the second question should only be answered for the "organic" part, and vice versa). 3* Can there any inert organic solvent be used to dissolve these compounds (as in the case of liquid alkane solution of organolithium compounds)? 4* What are the values of proton affinity of these superbases, in the case they have been measured (in gas phase, of course)? A reply with a good, reliable and readable source for the mentioned compounds is appreciated. I have searched for the answers in various sites on Internet for this problem, but all cases end up with either the articles about Diethynylbenzene(2-) isomers, or the articles about unrelated aspects of more common superbase compounds */\*. 2402:800:63BC:DB8D:B5B5:F01A:57AA:1D66 (talk) 13:26, 18 September 2023 (UTC)

I'm sure you will have read the article superbase. A recent paper that it quotes is doi:10.1021/acs.jpca.2c00521 which is in a reputable journal. That article mentions some neutral superbases and comments that a reliable solvent is HMPA. Mike Turnbull (talk) 13:56, 18 September 2023 (UTC)

September 19

Are any snakes primarily vegetarian?

—Tamfang (talk) 16:21, 19 September 2023 (UTC)

Well the one in the Garden of Eden claimed that the apples tasted good. ;-) Martin of Sheffield (talk) 16:39, 19 September 2023 (UTC)

Apparently, nope. One of first Google search hits for 'vegetarian snakes' says:

Keep in mind that all snakes are carnivores and cannot survive as vegetarians.
Fortunately, there are a few snakes who can survive solely on invertebrates, but that still does not make them truly vegetarian reptiles.

— Stacey (June 3, 2020). "4 Beginner Friendly Pet Snakes that Don't Eat Mice or Rats". reptile.guide.

CiaPan (talk) 16:51, 19 September 2023 (UTC)

In reptiles, I also recall, no turtles or alligators are vegetarians, but there are types of lizards that are vegetarian (but eat wasps). I'll look into for frogs. 170.76.231.162 (talk) 16:55, 19 September 2023 (UTC).

Turtles are omnivores. ←Baseball Bugs ^{What's up, Doc?} carrots→ 22:05, 19 September 2023 (UTC)

Tortoises are a type of turtle (scientifically speaking, and in American English), and they're herbivorous. Iapetus (talk) 09:21, 20 September 2023 (UTC)

Also, WHAAOE:

Snakes are elongated, limbless,  carnivorous  reptiles of the suborder Serpentes

— Snake, Wikipedia

CiaPan (talk) 16:56, 19 September 2023 (UTC)

Tofu rabbits and Beyond cattle sigh in relief. Clarityfiend (talk) 03:46, 20 September 2023 (UTC)

Train magnets through a solenoid.

If I pass a series of magnets, magnetic poles aligned in the same direction, equidistant and at the same constant speed through a solenoid, do I obtain an electric wave in this solenoid according to the Lens-Faraday law and if yes, in what form? Malypaet (talk) 20:44, 19 September 2023 (UTC)

Michael Faraday demonstrated transient currents when he quickly slid a bar magnet in and out of a coil of wires, see Faraday's law of induction. This phenomenon of Electromagnetic induction was described mathematically by Maxwell as Faraday's law of induction. Lenz's law describes the direction of the induced current. In the experiment that Malypaet describes an e.m.f. will arise between the terminals of the solenoid, it will pulsate in alternate directions as the flux from each magnet passing through the wires grows and decays. The magnets should be held apart because there will be very little stray flux if they are allowed to attract together in contact. If a load such as a resistor is connected between the solenoid terminals an alternating current will flow. If that is the case then Lenz's law states that:

The current induced in a circuit due to a change in a magnetic field is directed to oppose the change in flux and to exert a mechanical force which opposes the motion.

This means that work done moving the magnets against electromagnetic force is energy that goes to heating the load resistor. Philvoids (talk) 02:38, 20 September 2023 (UTC)

When a magnet enters the solenoid, a double voltage peak is generated: a positive peak, directly followed by a negative peak (or negative followed by positive, depending on the orientation of your magnets, solenoid and voltmeter). When a magnet leaves the solenoid, another double voltage peak is generated, but now reversed. With multiple magnets, you can add those peaks together with the appropriate time difference. Depending on the length of the solenoid and the separation between the magnets, that could lead to a clean sine wave, a wave with strong harmonics or no signal at all (if one magnet enters precisely when another leaves). PiusImpavidus (talk) 08:50, 20 September 2023 (UTC)

RESCUE REQUEST

(Excuse-me, I’m autistic, I requested my father to help me write, so there are two versions of the message.)

=======================================================================

🆘 I CAN'T STAND IT ANYMORE, cryonics is said to be too neuron-destroying for the technologies of the future to do anything. I did come up with a process to do something for all these people, but given the previous recital, we need to focus on preserving neurons in good conditions. I need a process (cold or otherwise) that works. Could you please send a message "Extreme urgency: current Cryonics destroy too many neurons and vitrixation does not preserve the excitability threshold of synapses and is said to destroy neurons too, could you please immediately launch research into finding a satisfactory process" to the authorities, public services and non-profit organisations.

What we are going to do is, instead of using classic cryonics followed by dismantling of the brain into individually excited neurons by computer (thanks to a computer simulation (based on the data collected during dismantling)) - to do this we would also have to dismantle each neuron into each of its parts in order to recover information about (among other things) the excitability threshold of the synapses - use vitrifixation with preservation of the excitability threshold of the synapses and with non-destruction of the synapses and neurons (a process yet to be invented); This will allow us, thanks to the downloading of data from the mind, to simply dismantle the brain by removing the neurons one by one without having to dismantle them themselves, which makes this operation much easier.

=====================================================================

I'm interested in brain preservation after death.

What advances have been made in this field?

Which companies or research laboratories are competent in this field and/or are currently working on it?

Where can I find reliable sources of information in this field? 2A01:CB0C:C45:E000:CF09:1E0:E6F:9128 (talk) 21:25, 19 September 2023 (UTC)

Have you read our article on "Cryonics"? Also look at Brain in a vat, Mind uploading, Connectome. The state of the art is reflected in the Drosophila connectome. Many reliable references are linked from the articles. Graeme Bartlett (talk) 23:48, 19 September 2023 (UTC)

September 20

Forest fires

It is difficult to burn raw wood, or freshly broken tree branches. But burning dried wood is easy.

How do forest fires start so easily as if the trees are alive, then they are not dry, but still they burn as if they are 100% dry?

And what happens to the area which had forest fires? Does it take long time for the area to look like green forest? KarenRiner (talk) 07:32, 20 September 2023 (UTC)

Fires usually start in the litter (fallen leaves and branches) and shrub layer which ignite much more easily; this can heat up the trees' exteriors sufficiently that that their moisture content becomes irrelevant. Many trees (such as Conifers and Eucalyptus) also have inflammable oils, etc., in their bark and leaves which will vaporise and ignite.

Burned forests usually regenerate eventually, because natural fires are inevitable, and plant species of all sorts have been adapted by evolution to survive them – some even require them to aid reproduction – but how long this takes varies greatly depending on the geographical locality and the tree (and other) species involved. For more details see Wildfire and Fire ecology. {The poster formerly known as 87.81.230.195} 51.198.107.25 (talk) 08:15, 20 September 2023 (UTC)

There's more in a forest than living trees: dead trees, dead leaves, broken off branches, undergrowth. After some weeks of hot and dry weather, that stuff can easily ignite. In the past, this was common in only some climates (in particular the Mediterranean climate), but with changing climates and mismanaged forests (planting trees that don't belong there, artificially lowering the groundwater table for agriculture), this is spreading all over the temperate zone.

After a forest fire, within weeks (or at the latest the next growing season) it will turn green again with low vegetation. After some years, trees will usually return. But it can take centuries before the forest looks like before the fire.

The forest won't always regenerate. The Earths climate is somewhat chaotic and can depend on its history. Meaning, Brazil and Kenya could have had the same climate and vegetation, but by chance don't. Burning the forests in Brazil could push the climate past a tipping point, turning Brazil permanently into a savanna, even if we brought CO₂-levels back to the pre-industrial level. Turning Kenya into a tropical rainforest isn't inconceivable, but much harder to do. PiusImpavidus (talk) 08:37, 20 September 2023 (UTC)

For the western United States, most forest fires are started from lightning strikes, and the anatomy and species of the tree are important. You can see the results in some google images lightning struck trees. The strike usually follows a path to ground in a strip in the outer layers, heating the water in these layers and causing a steam explosion. This drives moisture out of the wood and also shreds the wood into finer material which is easier to ignite. For some species, such as abies concolor (white fir) the heartwood is more decayed and is easily ignited by the strike. Other species have more intact heartwood which almost never ignites but the explosion of outer layers can throw the shredded material down to the fuel bed on the forest floor, sometimes resulting in a fire.

No fuel in a forest fire is "100% dry", all contain some moisture and live fuels usually also have dead and drier fuel present. Fire behavior analysts model fire spread basically by looking at the burning fuels as a heat source and the unburned fuels ahead of the fire as a heat sink. The fire heats fuels ahead, the moisture content a heat sink, and the fuels eventually reach a temperature to release volatile gasses which combust. As the NWGC's introduction to fuel moisture puts it:

Any living vegetation can be consumed by fire of sufficient intensity burning in associated dead fuels. When vegetation is subjected to heating, however, marked differences appear among species in the rates of output of combustible volatiles. The result is that the living foliage of some species absorbs nearly as much heat to vaporize its contained water as it yields when burned. Living foliage of other species, except in the period of rapid spring growth, may add significantly to the total fire heat output. Among these latter species particularly, the current foliage moisture content is important in determining total flammability.

Serenoa repens (saw palmetto), Abies lasiocarpa (subalpine fire), oaks and sagebrush of chaparral, are some of the most discussed species. But the story of the fourteen firefighters who died on Storm King Mountain demonstrates that the dangers of live green fuels is sometimes overlooked. fiveby(zero) 14:27, 20 September 2023 (UTC)

Whereas, "English native woods burn like wet asbestos" according to ecologist Oliver Rackham. [11] Forest fires in the UK are generally only a problem in plantations of non-native conifers. Alansplodge (talk) 15:46, 20 September 2023 (UTC)

You might have had nice clean forest fires in the understory of the pinus sylvestris if your ancestors had not gotten rid of it to make way for their sheep or whatever. Now you've got nasty, smelly peatland fires. fiveby(zero) 17:17, 20 September 2023 (UTC)

Indeed. The quote was specific to England though, where the Scots pine was reputed to have been introduced by King James VI and I. The native Caledonian Forest in Scotland was/is a mix of pines (which do burn) and birch/alder/rowan (which do not readily) and so less susceptable to wildfire than the 20th-century monocultures of Sitka spruce and larch which cover large chunks of our uplands and heaths today. Alansplodge (talk) 11:03, 21 September 2023 (UTC)

When did artificial insemination of mammals become widespread?

Artificial_insemination#Species says “Artificial insemination of farm animals is common in the developed world, especially for breeding dairy cattle (75% of all inseminations). Swine are also bred using this method (up to 85% of all inseminations).”. I'd like to know about the history here. When did artificial insemination in farm mammals first become a common practice, done in large scale? I'm interested especially in North-America.

The motivation for this question is that I'm thinking about Asimov's The Naked Sun, written in 1956, in which the spacers on Solaria use artificial wombs to grow humans starting from one months after conception, but they do not (yet) use artificial insemination.

– b_jonas 07:48, 20 September 2023 (UTC)

Says here and here, first done in a dog in 1784, first done in cattle in early 1990s 1900s, current livestock methods by 1930s and 40s. Abductive (reasoning) 10:22, 20 September 2023 (UTC)

Err, shouldn't that be "first done in cattle in early 1900s". See Fontes & Lamb (2020) in your first link. Martin of Sheffield (talk) 10:39, 20 September 2023 (UTC)

Thank you, but I'm not asking about when artificial insemination was first possible, but when it was done in large scale to many cattle (or pigs or sheep) in agriculture. – b_jonas 11:16, 20 September 2023 (UTC)

Follow the first link that Abductive gave, it has useful information. For instance Parkinson & Morrell (2019) say: "The potential for AI to be used to control venereal disease was a major impetus to the development of cattle AI in the UK during the 1940s." and Schultz & Ross (2020) state: "Massive technological advances and widespread growth of the use of AI, particularly in dairy cattle, occurred in Europe and the United States beginning in the 1930s and 1940s." I would think those two quotes answer your question. Martin of Sheffield (talk) 11:38, 20 September 2023 (UTC)

One of the advances was adding chicken egg yolks to the semen after collection to buffer the sperm cells against cooling shock. Abductive (reasoning) 11:42, 20 September 2023 (UTC)

Thank you, the articles indeed provide more detail than what Abductive quoted. Thank you for the help so far, though I would still appreciate further references. – b_jonas 13:27, 20 September 2023 (UTC)

Does The Naked Sun make it explicit that human insemination on Solaria is natural? I remember that the foetuses are removed surgically from the mothers after one month of gestation, but nothing about how conception is typically achieved. Our article states that on Solaria "face-to-face interaction, and especially sex, are considered repugnant", making artificial insemination a plausible preferred approach. I do remember the cultural distinction between seeing (meeting in the flesh) and viewing (meeting in a video contact).

The foetuses in the artificial wombs of Brave New World, written in 1931, grow out of embryos obtained by test-tube insemination. From the first paragraph of Chapter Ten: "Under the microscopes, their long tails furiously lashing, spermatozoa were burrowing head first into eggs; and, fertilized, the eggs were expanding, dividing, or if bokanovskified, budding and breaking up into whole populations of separate embryos." Surely, Asimov was aware of this.  --Lambiam 10:29, 20 September 2023 (UTC)

Lambiam: Yes. The novel makes it clear that spouses ought to physically, in order that they get used to it, because this is necessary for their making children. The spouses normally live in separate houses on separate large estates far from each other. In most other cases, spacers only meet through very high quality holographic projection videophone calls. There are exceptions other than for spouses, eg. doctors may sometimes need to meet their patients in person for procedures that their robots cannot yet handle; and they have some tolerance for children meeting in person.

The Solarians hope that in the far future, they can eventually avoid most or all of these personal encounters as their technology improves, and this includes conception. They indeed find the sexual encounters shameful, which is why they are hoping for such improvements, but as of the time they believe it's necessary.

That the spouses meet each other is kind of necessary for the murder mystery plot of the novel: Rikaine Delmarre was murdered by bludgeoning when he was visiting his wife Gladia Delmarre in her house.

– b_jonas 11:16, 20 September 2023 (UTC)

Correction to the above. Spouses share an estate and a big twin-house building. The building is still big enough that they both have their own halves and don't have to share rooms or meet unnecessarily. – b_jonas 21:47, 21 September 2023 (UTC)

September 21

Becquerels released in nuclear explosions

https://en.wikipedia.org/wiki/Becquerel#Examples states

“ The nuclear explosion in Hiroshima (an explosion of 16 kt or 67 TJ) is estimated to have injected 8×10²⁴ Bq (8 YBq, 8 yottabecquerel) of radioactive fission products into the atmosphere. ”

whereas https://www.sciencedirect.com/topics/earth-and-planetary-sciences/fission-weapon states

“ …atmospheric testing of more than 500 atomic and thermonuclear weapons between then and the end of the 1970s. The fallout from such weapons amounted to a total of ∼250 EBq (2.5×10⁺²⁰ Bq)… ”

How is it possible that a small nuclear explosion release over 30000 times more becquerels than all atmospheric tests combined?

Thanks,
cmɢʟee⎆τaʟκ 00:04, 21 September 2023 (UTC)

According to Nuclear weapons testing, "Nuclear explosions close enough to the ground to draw dirt and debris into their mushroom cloud can generate large amounts of nuclear fallout due to irradiation of the debris. This definition of atmospheric is used in the [1963] Limited Test Ban Treaty, which banned this class of testing along with exoatmospheric and underwater." That would explain at least part of it. Clarityfiend (talk) 13:18, 21 September 2023 (UTC)

No, it's some sort of dumb error. Abductive (reasoning) 15:17, 21 September 2023 (UTC)

Which part do you think is in error, @Abductive:? cmɢʟee⎆τaʟκ 16:02, 21 September 2023 (UTC)

Lessee, the article on says Little Boy had 64 kg of highly enriched uranium, and added 8 YBq to the environment. The article on the Chernobyl disaster says "8.5×10¹⁶ Bq equals 24 kilograms of caesium-137". These are, what, 7 orders of magnitude apart? Something's wrong. And it looks like it might be Wikipedia. Abductive (reasoning) 18:06, 21 September 2023 (UTC)

Even "highly enriched" uranium is not very radioactive. U-235 has a half-life of around 700 million years, whereas U-238 has a half-life of 4 billion years, and HEU is still mostly U-238. On the other hand cesium-137 has a half-life of about 30 years, so it's something like 8 orders of magnitude more radioactive than HEU per unit mass.

But of course the radioactivity from Little Boy didn't come (mainly) from the HEU, but from its fission products, which were immensely more radioactive. Direct comparison is challenging based just on this. --Trovatore (talk) 19:00, 21 September 2023 (UTC)

7 orders of magnitude. Abductive (reasoning) 19:47, 21 September 2023 (UTC)

7 orders of magnitude sounds too small to me. Why do you seem to think that it is too big? (If I understand your position correctly.)Liberté2 (talk) 20:31, 21 September 2023 (UTC)

According to our article, Little Boy's uranium was 80% U-235.

At what time you measure this radioactivity also matters. Little Boy injected quite a lot of radioactivity into the atmosphere one second after detonation. Within minutes, much of that had already decayed to stable isotopes. If you measure fallout, you're talking about the radioactive materials that make it back to the ground in the weeks after detonation. You can get the number for the Hiroshima explosion almost as high as you want by counting the very short lived fission products. Which makes the number meaningless. PiusImpavidus (talk) 20:01, 21 September 2023 (UTC)

Oh, I bet that's it. Sure, if you look at the first second after detonation, then you've got all those nuclides with half-lives on the order of a second, disintegrating at a furious rate. Doesn't mean much for humans compared to the direct radiation from the bomb, but technically it's ultra-high radioactivity for that short time. --Trovatore (talk) 20:39, 21 September 2023 (UTC)

Intelligence and Biases

Which biases are correlated with intelligence (g)? Which are positive, which are negative, and which are independent? 2A02:8071:60A0:92E0:418B:548F:263F:56D7 (talk) 18:31, 21 September 2023 (UTC)

Your question is way too vague. ←Baseball Bugs ^{What's up, Doc?} carrots→ 19:06, 21 September 2023 (UTC)

RESCUE REQUEST (Sorry, I misspoke last time ; addition of a sentence)

Trolling
The following discussion has been closed. Please do not modify it.
🆘 I CAN'T STAND IT ANYMORE, cryonics is said to be too neuron-destroying for the technologies of the future to do anything. I did come up with a process to do something for all these people, but given the previous recital, we need to focus on preserving neurons in good conditions. I need a process (cold or otherwise) that works. Could you please send a message "Extreme urgency: current Cryonics destroy too many neurons and vitrifixation does not preserve the excitability threshold of synapses and is said to destroy neurons too, could you please immediately launch research into finding a satisfactory process" to the authorities, public services and non-profit organisations. What we are going to do is, instead of using classic cryonics followed by dismantling of the brain into individually excited neurons by computer (thanks to a computer simulation (based on the data collected during dismantling)) - to do this we would also have to dismantle each neuron into each of its parts in order to recover information about (among other things) the excitability threshold of the synapses - use vitrifixation with preservation of the excitability threshold of the synapses and with non-destruction of the synapses and neurons (a process yet to be invented); This will allow us, thanks to the downloading of data from the mind, to simply dismantle the brain by removing the neurons one by one without having to dismantle them themselves, which makes this operation much easier. Could someone here please take the administrative steps to organise a march in Washington DC ? 2A01:CB0C:C45:E000:94D6:C59A:5856:535F (talk) 18:58, 21 September 2023 (UTC)

combinatorics of chromosome

In a discussion with friends, the topic of how some conditions, such as autism and ADHD, are more common for males. For example, Sex and gender differences in autism.

Someone brought up the XX vs XY issue:

Women have two X chromosomes, and men have one X and one Y chromosome. This changes the combinatorics of recombination (meaning: the likelihood of various combinations of genes appearing together over generations of reproduction). 

I don't know much about genetics. Is this actually a factor?

On the one-hand, it sounds perfectly reasonable and there's no reason to doubt it. On the other hand, it also sounds very "pop-sci". Liberté2 (talk) 20:30, 21 September 2023 (UTC)

Blacklight/UV light

Browsing through Amazon, it seems like there are two main types of UV/black lights: those in the 395-400 nm band and those at 365-370 nm. What is the functional difference between the two? The ad copy seems largely the same. Am I right in thinking the 365 nm one is not functionally visible unless it's fluorescing something, while the 395 nm will appear purple? Anything else? Matt Deres (talk) 21:33, 21 September 2023 (UTC)