Wikipedia:Reference desk/Archives/Science/2019 July 11

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July 11

Another cats question.

Okay I already know that mother cats are known to take care of kittens not of their own, including infants of other species. So what if you have 2 female cats, 1 neutered and 1 non-neutered. And they were childhood friends. Then the non-neutered cat gives birth. Say we shortly take the mother away, then will the neutered female cat attempt to look out for the kittens? Obviously she can't milk, but she could at least look out for them in the event of outsiders. 67.175.224.138 (talk) 04:28, 11 July 2019 (UTC). Edit: I wonder if something like this has ever been experimented. 67.175.224.138 (talk) 04:33, 11 July 2019 (UTC).

Even male cats have been observed to spontaneously start caring for random kittens they just met. At least one wild lioness has been observed taking care of juvenile gazelles. I don't know that anyone has attempted a study that could predict this behavior. Someguy1221 (talk) 04:37, 11 July 2019 (UTC)

Cross-fostering might be helpful. Klbrain (talk) 06:50, 11 July 2019 (UTC)

Had this happen with my own cats. So, yes. --Khajidha (talk) 09:30, 11 July 2019 (UTC)

Would your cat as much bring food to the kittens? 67.175.224.138 (talk) 17:27, 11 July 2019 (UTC).

Being hit by speed of light velocities.

How painful/destructive is it if you were hit by an electron near the speed of light? Then for proton, and cesium atom (the largest non-radioactive atom), and for a water molecule? I heard that if you had something the size of a basketball, made out of nickel, if launched against the Earth can destroy it if it was near the speed of light. Shrugs. 67.175.224.138 (talk) 04:32, 11 July 2019 (UTC).

This question has been answered (more or less) for a baseball, here. --69.159.11.113 (talk) 05:18, 11 July 2019 (UTC)

A single atom or molecule would not do any significant damage; it would just pass through you and back out, just like cosmic rays do. A baseball or basketball is much bigger than that scale. Incidentally, caesium is the largest atom, even without the "non-radioactive" qualifier: francium is smaller than caesium due to relativistic effects. Double sharp (talk) 07:53, 11 July 2019 (UTC)

I don't believe they would behave like cosmic rays, since an atom has an electron shell that would interact with other atoms it passed through. It might still not be noticed, though, as even if it destroys a million atoms, that's still a minute portion of the human body. However, note that actually going the speed of light would be impossible, requiring an infinite amount of energy, so we would have to be content with 99% or so. Also, the person would have to be in a vacuum, or the atmosphere would react with the fast atom. And being in a vacuum certainly would affect the body. Maybe you could have a narrow tube, only a few atoms inner diameter, with a vacuum in it, touching the skin, and fire the atom down that. SinisterLefty (talk) 14:17, 11 July 2019 (UTC)

What would the atom reacting with the atmosphere do? Imo, couldn't an atom travel so fast that it loses it's electrons? 67.175.224.138 (talk) 17:29, 11 July 2019 (UTC).

Or it might never have had them. An Alpha particle is effectively the nucleus of a Helium atom that was created (as a separate entity) without any electrons. {The poster formerly known as 87.18.230.195} 2.122.177.55 (talk) 17:51, 11 July 2019 (UTC)

Right, but the OP specified atoms and molecules, which includes the electron cloud, so I tried to find a scenario where those could hit a person while going nearly the speed of light. Speed alone shouldn't shake loose electrons, but hitting something at those speeds sure could. SinisterLefty (talk) 20:29, 11 July 2019 (UTC)

Something important to understand here is that anything with mass can never reach c (the speed of light in a vacuum), but it can get arbitrarily close. However, the amount of energy needed to accelerate said thing grows exponentially as you get closer to c. See Lorentz factor for more detail. If you could accelerate something to an outrageously high Lorentz factor, you could get its kinetic energy to exceed the binding energy of Earth. To see this, you could try out some calculations yourself using the math from the Lorentz factor article. However, a practical means of doing this is left as an exercise for the reader. You might find this page interesting. --47.146.63.87 (talk) 08:38, 12 July 2019 (UTC)

The relativistic kill vehicle is a trope of science fiction. There are some calculations at the linked article. I think there was once a Wikipedia article or section about the concept, but I wasn't able to find it just now. 173.228.123.207 (talk) 21:49, 12 July 2019 (UTC)

Guys, I purposely said "near the speed of light." And I purposely didn't say a specific percentage like 99% or 95% the speed of light. Please and I'm sick of these posts about "it's impossible to go to the speed of the light" posts. I know that. That wasn't my question. 67.175.224.138 (talk) 03:56, 13 July 2019 (UTC).

Autism question

Is there a name for this strange phenomenon I've noticed in myself? What I've noticed is that when I try to do what I want to do, my body often does something different. Of course, I'm aware that the brain and the rest of the body work together to accomplish things, and the prefrontal cortex does not act in a vacuum. For example, a person might not want to vomit (That choice would involve the prefrontal cortex, right?), but the vomit area of the brain becomes activated and he or she does vomit anyway. However, I've noticed some exceptionally strange things about myself and about how the different parts of my brain try to work together to do things. For example, I might try to walk as straight as I can, and the more I try to walk straight, the more I can't. This also happens when I type. It's as though I don't want to type a wrong letter (such as an "a" instead of an "s"), and somehow, my brain gets confused and makes me type the "a." Now, I realize that autism (especially classical autism - and I have no reason to suspect that I have anything other than that) is known to affect pretty much every single region of the brain, so I'm wondering whether autism somehow affects the "cooperation" between the different parts of the brain. I've heard of conditions such as alien hand syndrome, so I'm wondering if there might be a name for this autistic trait.75.117.54.5 (talk) 06:55, 11 July 2019 (UTC)

Wikipedia does not give medical advice. Bazza (talk) 08:15, 11 July 2019 (UTC)

vomiting is full of info.

normal, not autistic person also experience the "the more I try the less I succeed" effect. A classical example of that is military cadence marching. Or, indeed, typing. This happens when you try to control things instead of letting them happen on their own Gem fr (talk) 01:02, 12 July 2019 (UTC)

I've heard that called the centipede's dilemma. 173.228.123.207 (talk) 21:37, 12 July 2019 (UTC)

Yes, thank you! I wish I knew that before Gem fr (talk) 10:33, 13 July 2019 (UTC)

I've modified the above response returning it to what the IP original wrote before it was inappropriately modified by a third party [1] [2]. Nil Einne (talk) 15:06, 14 August 2019 (UTC)

Life vest vs Parachute

Why do airlines offer customers a life vest under their seats in the case of a sea "landing". Statistics prove that the chances of surviving a sea landing in a commercial airliner are pretty slim. However, statistic also show that parachuting from high altitude has a fairy low mortality rate (I know, I know, these are trained people taking great risks and carefully calculating their actions etc). I am aware that parachuting at high speed is deeply dangerous and more than likely will kill you, but surely if you're going to die anyway, at least give the customer's a fighting chance to land gently in the ocean to be eaten by sharks rather than smashing into the ocean still strapped to your chair by a useless seat belt. Why a seat belt, air supply and life vest rather than an oxygen canister and a parachute? Thanks — Preceding unsigned comment added by 81.131.40.58 (talk) 10:11, 11 July 2019 (UTC)

If you stop and think about it, your idea is not practical. ←Baseball Bugs ^{What's up, Doc?} carrots→ 10:37, 11 July 2019 (UTC)

Much of it is just trying to keep the passengers calm so that they don't make the situation worse. The chances of survival may be low, but they'll be lower still if panicking passengers are running loose and possibly getting in the way of the pilot. --Khajidha (talk) 11:20, 11 July 2019 (UTC)

At the very least, everyone would have to wear their parachute for the entire trip, and the safety card would have to explain how they work... which would get real interesting for someone carrying an infant. ←Baseball Bugs ^{What's up, Doc?} carrots→ 12:57, 11 July 2019 (UTC)

Googling "why don't planes carry parachutes" will give you lots of pages with good reasons. E.g. this one. AndrewWTaylor (talk) 13:29, 11 July 2019 (UTC)

Just a few reasons:

1. Parachutes are far more expensive.
2. They are more difficult to put on and use (there are some that automatically deploy, but those are even more expensive).
3. They take up more room and are heavier.
4. They would require opening a door in flight to jump, and almost all passenger planes are designed to prevent that, as the air pressure differential holds the doors shut. DB Cooper was flying in a plane which was an exception.
5. Jumps would need to occur at low altitude and speeds to be survivable. A jet plane likely couldn't get enough lift at those speeds to stay aloft long enough for everyone to jump. SinisterLefty (talk) 14:00, 11 July 2019 (UTC)

Skydiving is usually done from a plane that's flying level. A plane nose-diving toward the ground would make it more difficult. And even forgetting that - as you suggest, the time window of survivability would be rather short. ←Baseball Bugs ^{What's up, Doc?} carrots→ 14:33, 11 July 2019 (UTC)

What about fighter jets that have ejection seats, surely this is the same principle and it works for them. — Preceding unsigned comment added by 81.131.40.58 (talk) 14:41, 11 July 2019 (UTC)

Those are highly trained professionals with expensive and sophisticated equipment. Not at all the same as random travellers on a passenger jet. --Khajidha (talk) 14:44, 11 July 2019 (UTC)

PS - Read the article that AndrewWTaylor linked to. Parachuting from a passenger jet at cruising altitude is not just grabbing some rinky-dink canvas bag and strapping it to your shoulders like a book bag. --Khajidha (talk) 14:46, 11 July 2019 (UTC)

Or just convert every seat in the plane to an ejection seat. That shouldn't cost too much. ←Baseball Bugs ^{What's up, Doc?} carrots→ 15:09, 11 July 2019 (UTC)

I hope that was meant sarcastically. Among other things, consider that the passenger seating occupies the widest part of an airliner, with lots of other stuff both above and below the passenger cabin. --69.159.11.113 (talk) 20:05, 11 July 2019 (UTC)

Precisely. And yet another reason why the OP's idea is not practical. ←Baseball Bugs ^{What's up, Doc?} carrots→ 20:43, 11 July 2019 (UTC)

• In addition to all the reasons given above, consider the time needed to make everyone jump. My guesstimate would be one hour to evacuate a full commercial airplane of a couple hundred passengers (skydiving companies like this say about 10s between jumpers, but that's for people who paid for it, watched the instruction video and are ready, not frightened civilians). One hour might be a tad too much for a crisis situation of "OMG we are gonna crash soon". Even if it is not, it means the passengers are scattered over a very large distance (airplanes go at Mach 0.85 which is about 1000km/h) so the rescue operation is going to be difficult (presumably, the aim of parachuting passengers is not to let them freeze to death in ocean water). Tigraan^{Click here to contact me} 14:58, 11 July 2019 (UTC)

To really understand the motivation, you have to comprehend that the purpose of a life-vest or a life-raft is to improve the statistical rate of survival after a water landing. In that specific type of emergency, many - or all - occupants of the aircraft will live without injury; and they only need to stay afloat long enough for a rescue craft to arrive. These flotation aids are intended to reduce the rate of death by drowning.

The life-vest or life-raft is not designed to be the solution to other types of emergencies.

So, with this context in mind, the line of inquiry would be - why is this specific type of emergency worth preparing for?

To answer that, maybe the best place to start reading is the summary statistics for aviation accidents in the United States. Very few accidents on air-carrier ("airline") operations are actually fatal; very few have any relation to an impact or a mechanical failure. In the event that an aircraft loses partial or total propulsion over land, it is very likely that a pilot can bring the aircraft in for a safe and "normal" emergency landing with zero fatalities.

In the event that an aircraft loses propulsion over water, the water landing is almost certainly survivable; the accident can remain "non-fatal" as long as every passenger can egress and stay floating. So, at a policy level, we're engineering a solution to take a big chunk out of the "pie-chart" of all possible fatal accidents. We're not even trying to solve every accident with this specific method. We have other methods, tools, equipments, policies, and so on, to deal with the other pie-slices. On inspection of the overall "pie" - the set of statistics of all civil aviation accidents, over time - well, the slice of accident-conditions that could possibly be "improved" using a parachute is so small as to be not even worth dealing with. This is a data-driven conclusion based on real research - we solve the safety problems that actually need to be solved, not the ones that people imagine to be serious.

If you're a super-wonk who is actually serious about safety, FAA's Civil Aerospace Medical Institute program in Oklahoma offers zero cost water egress training to interested participants:

• CAMI Safety Training brochure
• facilities brochure.

You can live through a water-emergency, and with training, equipment, and engineering, we can improve the survival rate for more people in more serious emergencies.

If you're looking for more background reading, here is:

• the SAE's standardization body for Aerospace, Committee S-9: Cabin Safety Provisions Committee. They are a team of international engineering experts whose recommendations are codified and recommended by American government regulators (among others).
• SAE Aerospace Standard AS-1354: Individual Inflatable Life Preserver
• 14 CFR §121.340, the specific American legal regulation that mandates a method of emergency flotation for overwater flights, with additional citations to the legislative actions of the early 1960s that led to creating that specific rule. No equivalent legal requirement exists for the provision of parachutes to passengers. Elsewhere in the world (one hopes) the local government has a similar or equivalent standard requirement.

Nimur (talk) 17:01, 11 July 2019 (UTC)

It's even possible that parachutes for everyone could increase fatalities, by increasing the plane weight, such that when it has very limited lift, for whatever reason, this added weight could cause it to crash before it reaches a runway. SinisterLefty (talk) 21:00, 11 July 2019 (UTC)

Not only possible, rather sure. I skydived. Hundred of jumps. And I used airlines, too, so I wondered. Well, after thought, I have rather stay fastened to my seat in crash position. Far better survival chance than pretending to stay cold-blooded, try to wear a parachute with oxygen mask on, then crawl to an exit (in a jerking, rocking and rolling plane full of panicked bodies, luggages, objects, scary sounds...), just to find out that the plane is actually too low (most trouble occurs when landing or taking off, that is, at rather low altitude, while you ask a least 300 m (1000 feet) even in automatic parachuting) for the parachute to do any good (even if I actually put it correctly, which is not sure, and nobody will have checked it for me as we always do before jumping from a stable plane). And, then again, I know how to jump (when everything is OK! I am no super hero and wont claim to do thing properly -- or even just do thing, actually, instead of freezing or panicking -- in a imminent crash context). Untrained people? They might as well go hang themselves; better result.

The only way parachutes could be useful, would be to design seats so that are actually escape pods, quite like in military aircraft. Except that, chance really are that a military aircraft get downed, while civil planes are actually safer than cars, so the point of this is not sure. Gem fr (talk) 23:28, 11 July 2019 (UTC)

I rather suspect that the most likely impact of issuing parachutes to passengers would be to scare them away from flying altogether. As you suggest, plane crashes are rare. Automobile accidents are a much likelier cause of death for a given individual. ←Baseball Bugs ^{What's up, Doc?} carrots→ 23:47, 11 July 2019 (UTC)

I concur. Transportation is choke full of example where trying to improve safety has the opposite effect (because it push people away from an already safe behavior, toward a more dangerous one) Gem fr (talk) 00:49, 12 July 2019 (UTC)

The original question is a cousin to the old semi-joking question, Why don't they make the whole plane out of the material they make the voice and data recorders from? The answer is that the plane would be too heavy to take flight. Basically you'd have a big bus with wings. (At least there'd be no need for parachutes.) ←Baseball Bugs ^{What's up, Doc?} carrots→ 11:40, 12 July 2019 (UTC)

LOL. No need for wings either. BTW my understanding is that they seriously consider getting rid of recorders, in favor of immediate transmission (which could allow detecting malfunction and helping in rescue before a crash even happen, instead of just analyzing it. Gem fr (talk) 13:02, 12 July 2019 (UTC)

They should do both. ←Baseball Bugs ^{What's up, Doc?} carrots→ 16:17, 12 July 2019 (UTC)

Agreed. Not sure how reliable a transmitted signal is, as it requires more functional equipment than a flight recorder (more power, a working antenna, etc.) and a lack of interference. Also, the signal may be lost if in a mountain valley, or too low over the ocean, etc., that is, the type of conditions that often precede a crash. SinisterLefty (talk) 13:37, 13 July 2019 (UTC)

"Global heating"

How plausible is this scenario? Global heating: London to have climate similar to Barcelona by 2050, Cities of the future: visualizing climate change to inspire action

If that's true, then future really doesn't bode well for the city I'm living in, Zagreb. But, while summers seem to be getting a little warmer on average - I can't really say much for sure from experience, I'm only about 30 - our all time high record is almost 70 years old. I think we would've broken it by now if summers are going to heat up by 7.3C? Also the 7.3C summer temp increase doesn't fit the page's idea that climate will be similar to Louisville, if that really happened we'd be getting in the Port Hedland neighborhood ... 93.136.99.57 (talk) 22:00, 11 July 2019 (UTC)

Note that global climate change does not result in uniform warming. Some areas warm faster, some slower, and some even cool down due to shifting weather patterns. So, you certainly can't expect the same change in Zagreb as in London. SinisterLefty (talk) 23:57, 11 July 2019 (UTC)

grauniad-grade. As they themselves admit, this is "to inspire action". That is, to suspend thinking by fear and sense of emergency. Confidence trick.

London is under the influence of North Atlantic Ocean. Barcelona, under the influence of Mediterranean sea. North Ocean temperature increased at the whopping rate of ... well, it actually cooled. Never mind.

Too bad, this for sure would have been quite an improvement for London.

As a rule of thumb, the closer to the pole you get, the more climate change has effect. Arctic ice is still there, despite it was supposed to disappear long ago it you were to trust the guardian.

As another rule of thumb, the guardian is a cool horror stories collection, full of flamethrowing, cosmos-destroying, undercover nazis detected by ″experts″; but to be trusted, not so much... Gem fr (talk) 00:24, 12 July 2019 (UTC)

The Guardian is not the top resource when it comes to science (nor is any mainstream newspaper btw). Regardless, anthropogenic global warming is real, and so is arctic sea ice decline. Tigraan^{Click here to contact me} 08:39, 12 July 2019 (UTC)

Indeed. But very far from the guardian's rocky horror picture show, which, by its own admittance, is just meant to inspire action by exaggeration aka plain lies (also, my understanding of motivation is that this is very counter-productive, BTW. "stop, you fools, your action will result in Troy in flame" only results in the demise of the warning people). Newspapers (any of them) being "not the top resource when it comes to {whatever}" is quite an understatement Gem fr (talk) 09:29, 12 July 2019 (UTC)

• For our non-British readers, the Guardian is a well respected quality newspaper, particularly known for its investigative journalism. I suspect Gem fr has ideological reasons for their very inaccurate description of it, or perhaps they meant to talk about the Daily Mail, in which case the statement was largely accurate. Fgf10 (talk) 08:53, 12 July 2019 (UTC)

to call the guardian a "well respected quality newspaper" is a grauniad-grade joke. I suspect Fgf10 has ideological reasons for their very inaccurate description of it, contradicted by example I just gave and countless "OMG thing are far worse that they were/expected to be" clickbait articles. I concur that the daily mail is another cool horror stories collection, but at least the DM as the good taste (hum hum) to mitigate and cheer up readers with lots of boobs and royals/celebrity futilities, while the guardian I see boringly humorlessly serious-minded. Gem fr (talk) 09:29, 12 July 2019 (UTC)

You might not like it, but those are just the facts. It is only not well respected in far-right circles. Also, you do realise the don't make up the science right, they just report on it? You seem to understand both the science behind climate change and how journalism works. -- Fgf10

You might like it, but calling this kind of garbage "facts" or "science" is just outrageous. And the word you should use instead of "report" is "stage". I'll change my mind the day the guardian publish a piece like "remember the "scientist" who told you that arctic ice would disappear in 4 years? well, 7 years later, turns out his "science" was astrology-grade". Spoiler-alert: not gonna happen. (as for your name calling It is only not well respected in far-right circles, the shame is on you) Gem fr (talk) 12:36, 12 July 2019 (UTC)

Please see the works of Bjorn Lomborg much of the climate change drama is exaggerated. It is real and it is a problem but we will cope. As for the UK being hotter than Barcelona by 2050, A. Barcelona will also be heating up according to mainstream climate change theories, or will be underwater and B. UK hotter than Barcelona? Sounds great, bring it on! and C. evey one please try to remain calm and remember the Y2K crisis which everyone conveniently forgot on January 2nd 2000 after realising they had been duped. My 486 still worked just fine. Anton 81.131.40.58 (talk) 10:33, 12 July 2019 (UTC)

Y2K was not a hoax. My company had a lot of date fields that were specifically written in YY-MM-DD format which had to be reconfigured to YYYY-MM-DD in order to prevent the year going to 00 and causing trouble with date comparisons. Your PC's date calculation algorithm may not have had that problem. And if it was "forgotten" after the year rolled over - well, that was the entire point of doing that work. ←Baseball Bugs ^{What's up, Doc?} carrots→ 11:33, 12 July 2019 (UTC)

Bjorn Lomborg is an economist and quite shaky on the science. And his main concern was about the relative importance of climate change compared to things like malaria and I would have to agree that allocating resources for everything is a big problem. But we have to do something about climate change and the sooner the less painful. As to Y2K there was no organized Y2K denial and the reason it passed without trouble was because people did take it seriously in advance. Dmcq (talk) 11:24, 12 July 2019 (UTC)

Actually, it turns out that "the sooner we do something about climate change, the less painful" became "we must show we care, and greenwash as much as possible, even if what we do actually worsen the problem we claim to solve" and "what a great opportunity, almost as good as terrorism, to frighten people into 1984-like politics" and "screw the western working class, we have a cosmos to save (and Chinese work force to tap for even more profits, what a coincidence)". And this resulted in silly move such like Energiewende in Germany, subsidizing Tesla cars, the destruction of ironworks with only effect to move the industry to India or China, and solar/wind crap. Renewable energy is making giant step progress, and will take over at some point, but it was a child prematurely put to work. At some point you have to evaluate things not out of their aim, but out of their actual results. Gem fr (talk) 12:36, 12 July 2019 (UTC)

• Sorry no offense, but it sounds to me that you don't believe in climate change at all. I'm interested in the opinions of people who do agree with the scientists, on whether we can expect the change to suddenly turn catastrophic in the next 30 years. (Since summer warming here has been so far on a pace far far slower than 7.3C per 30 years.) 93.136.69.75 (talk) 21:15, 12 July 2019 (UTC) (OP)

Au contraire, climate change is real. Hell, humanity works hard just for this very purpose. Some say we may even skip the next glacial period, which would be great for those alive at the time (not me, not you, so we would be mad if we cared anyway). Gem fr (talk) 10:00, 13 July 2019 (UTC)

The thing is, your question has no scientific sense at all. Can you spontaneously turn into a lump of gold? Yes you can, according to well established quantum mechanics theory; chances are low, though... can we expect the change to suddenly turn catastrophic in the next 30 years? has a very simple answer, as science goes: NOBODY-KNOWS, Period. Longer (same) answer: Science (math of chaos) is very clear, this just cannot be answered with any serious level of confidence. And in fact, if you read them carefully, all such scaremongering pieces are written in a special way. Choke full of if and could and may and trust me I am the expert (which actually translate as my work is guarantied science-free according to Feynman "Science is the belief in the ignorance of experts", but unaware minds don't know that) and I am not telling you that, you just figure it yourself, you are so smart. So that, afterward, the author can deny having made any prediction, so he wasn't wrong. Not even wrong. So, just disregard it. Even "is there anything fun to watch?" would be more important than falling prey to unwarranted worries (and there ARE more important questions, right now). Gem fr (talk) 10:00, 13 July 2019 (UTC)

I've moved your answer here because it has nothing to do with the question I asked 47.146, and I'd like to have an answer to that question, I think it would tell me immediately how trustworthy. Please reply here if you will. To reply: are you aware that all those things you describe can be applied to your own writings? You're asking me to assume that a large amount of papers on climatology are the result of malevolent confidence trickery and fraud, while your own statements are vague and unfalsifiable. For example "screw the western working class, we have a cosmos to save (and Chinese work force to tap for even more profits, what a coincidence)", do you expect me to believe that climate change activism caused job automatization on the whole or are you going to correct me that you meant to say that it was actually a tiny contributor? Your own logic is only backed by your own reputation as a person well-read enough to write "Grauniad", and some things you write ("Science (math of chaos) is very clear, this just cannot be answered with any serious level of confidence.") conflict with disciplines of science that have been around for decades (at least catastrophe theory and climate tipping points). I want this paper to be wrong too but what you write convinces me no more than that paper, so please back off with the attacking what-a-stupid-thing-to-ask tone. 93.142.75.226 (talk) 22:41, 13 July 2019 (UTC) (OP)

You want me to substantiate, fair enough.

Did climate change activism caused job automatization? No. It, for instance, caused the USA to hinder its coal industry, and it caused the EU to subsidize destruction of ironworks in Europe and its moving to India, and it caused the ~trillion euros, paid through electricity price ~2x what it is in France, hurting most low income homes. This qualify as "screw the western working class etc.", don't you agree? (It also probably hindered, not caused, job automatization and efforts to cope with global pollution).

Indeed, math conflict with some part of climatology. Not all climatology, for obvious reasons, among which: Edward Norton Lorenz. Hell, "we cannot say at present, on the basis of observations alone, that a greenhouse-gas-induced global warming has already set in, nor can we say that it has not already set in" (ref name="Lorenz91" https://www.sciencedirect.com/science/article/pii/B9780444883513500350 ), and The Guardian push a paper that says he can calculate how much the greenhouse-gas-induced global warming will be in a specific city? (although, as noted before, "will" is not used, only "could" and conditional and innuendo)? The same newspaper that pushed a paper telling that the arctic ice should had disappeared years ago, and never pointed out that it never happened? What a joke, although, not a funny one. That 9-year old kids are scared to put vinegar on baking soda for fear of global warming is not funny (see question below), it is child abuse and terrorism.

You want this paper to be wrong? I don't. I want it to be able to be wrong, to begin with, so it could qualify as science. But can it be? Is there is a way you can disprove it? Can you put a fact in front of it and say "see? this happened (resp: not happened), that your paper said id could not happen (resp: had to happen), so your paper is wrong"? Answer is: no. It is, literally, not even wrong. Not science. Just discard it, as if it never happened as far as science is concerned (it did happen, of course, but in the propaganda universe aiming to -- and succeeding in-- scare 9-years old).

sorry you are upset, but, nevertheless, your question has no scientific sense at all -- which doesn't make it stupid-thing-to-ask at all, either. It is just another instance of "my horoscope says I have great love opportunity today, is it true?": we can answer that astrology is garbage, but we have no way to scientifically assess whether someone do have great love opportunity or not. Gem fr (talk) 09:18, 14 July 2019 (UTC)

19 years and you still can't admit your folly huh Bugs? tsk tsk Anton 81.131.40.58 (talk) 14:18, 12 July 2019 (UTC)

It had to be done. To have not done it would have been the folly. ←Baseball Bugs ^{What's up, Doc?} carrots→ 16:16, 12 July 2019 (UTC)

For once, I agree with Mr Bugs. That no catastrophe such as a plane falling out of the sky actually occurred, does not tell us anything about whether or not it would have happened had the Y2K bug not been fixed. The point was, it was seen by serious, reasonable, practical people as a distinct possibility. That the community took steps to make sure that no such event occurred is a testament to the thoroughness with which this issue was addressed. There was no element of folly in this. It's a bit like getting your kids vaccinated; they might never have got the disease anyway, but you're making sure they don't. That they don't get it doesn't prove it was folly to vaccinate them in the first place. Unless you're an anti-vaxxer, in which case I have nothing more to say to you. -- Jack of Oz ^{[pleasantries]} 00:58, 15 July 2019 (UTC)

As an additional comment, I've seen models that indicate that one of the areas that will be least affected by the planetary increase in temperature in terms of local temperature is the US East Coast (Boston to North Carolina or so) since any melting in Greenland is likely to feed more cold water into the cold current going south along the US East Coast... — Preceding unsigned comment added by Naraht (talk • contribs) 16:58, 12 July 2019 (UTC)

Bad as this may look, it's just a minor prelude to much worse to come. As pointed out here: "The history of the Earth system is a story of change. Some changes are gradual and benign, but others, especially those associated with catastrophic mass extinction, are relatively abrupt and destructive. What sets one group apart from the other? Here, I hypothesize that perturbations of Earth’s carbon cycle lead to mass extinction if they exceed either a critical rate at long time scales or a critical size at short time scales. By analyzing 31 carbon isotopic events during the past 542 million years, I identify the critical rate with a limit imposed by mass conservation. Identification of the crossover time scale separating fast from slow events then yields the critical size. The modern critical size for the marine carbon cycle is roughly similar to the mass of carbon that human activities will likely have added to the oceans by the year 2100."

And we can read here: "As discussed earlier, parallels exist between the Anthropocene and the PETM in terms of carbon input and climate change. Does this also imply similar impacts in terms of species extinction and recovery? We argue that the Anthropocene will more likely resemble the End-Permian and End-Cretaceous catastrophes, rather than the PETM. First, the present extinction rate of the Anthropocene is more than 100 species per million species per year, while the fossil record indicates background extinction rates of marine life and mammals of 0.1–1 and 0.2–0.5 species per million species per year, respectively [93]. In other words, the current rate of species extinction is already 100–1000 times higher than would be considered natural. The causes for the current extinctions are diverse, including factors such as changes in land use and fresh water, pollution, exploitation of natural resources, etc. Second, with respect to ocean acidification and impacts on marine calcifiers, the anthropogenic carbon input rate is most probably greater than during the PETM, causing a more severe decline in ocean pH and saturation state (figure 5). In addition, changes in ocean chemistry and sea surface temperature will be imposed on ecosystems that are already affected by other environmental factors. Analysis of the marine fossil record suggests that, if the Anthropocene mass extinction rivals the K-T or End-Permian disasters, recovery will take tens of millions of years [16]. At this point, there are obviously large uncertainties regarding the progression of the rate of extinction and origination, dispersal and success of species in the future. However, if the current trend of species extinction continues, the geological record tells us that humans will have a major and long-lasting impact on the evolution of species on this planet for millions of years to come." Count Iblis (talk) 19:45, 12 July 2019 (UTC)

It took me some time to grok this. What does the "critical size for the marine carbon cycle" stand for? I'm guessing it's the point where evaporation of CO2 from oceans causing heating and heating causing evaporation of CO2 will create a runaway reaction. Could this really produce warming on the scale of several degrees per decade? I'm aware that most likely Earth is toast long term (thank you old people), I'm wondering if it's plausible that the climate will completely change within my lifetime. 93.136.69.75 (talk) 22:26, 12 July 2019 (UTC)

The paper Count Iblis discussed focuses on what might be sufficient to provoke a mass extinction. It isn't directly looking at global temperatures. As to your original question, the site predicts for Zagreb an increase in the maximum summer high temperature by 7.3 °C. The average temperature (the arithmetic mean) is predicted to increase by 2.3 °C. These are two very different figures, and well within the ranges predicted by models for much of the globe. If you haven't, read, if possible, The Uninhabitable Earth (I suggest the annotated version). In the past, even more rapid changes in climate have happened; during the Paleocene–Eocene Thermal Maximum, average global temperatures rose by around 5 °C within about thirteen years. Now, will this happen in our near future? Not necessarily. Predictions from the IPCC Fifth Assessment Report are based on different Representative Concentration Pathways, which predict between 0.3 to 4.8 °C of warming depending on emissions. (We're already above the low-end estimate.) Again, these are average global temperatures. To predict the effects on a specific region, you need studies that look at that region. For one example, models for Tibet give a high-end estimate of 6.1 °C. Note that for human habitability, humidity is as important as air temperature. Wet-bulb temperature takes into account both; heat index is another such figure. And of course, the effects of global warming go far beyond air temperature, and will affect weather patterns, agriculture, sea level, human health, flora and fauna, and much more. --47.146.63.87 (talk) 00:48, 13 July 2019 (UTC)

Yes, the average summer temperature increase seems reasonable. In the past decade avg temperature in summer months was 3C over the 1960-1990 mean, so another 2.3C over another 30 years is about at pace (avg temperature for the entire year has been growing slower). What is this maximum temperature tho? The average highest temperature of the year is now I think probably 35-38C, I'm having a hard time seeing how we can push another 7C on top of that with our humidity levels, let alone that that would be the "best case scenario", and how that would put us near Louisville and not for example, Dubai. 93.136.69.75 (talk) 03:01, 13 July 2019 (UTC) (OP)

Phase diagram

Can a compound's phase diagram be determined based purely on theoretical analysis of the compound's structure, etc., or must it be found observationally? Loraof (talk) 23:48, 11 July 2019 (UTC)

In theory, yes. In practice, oof. This is related to what are called equations of state. That is, functions of the state of matter (temperature, pressure, etc) that yield physical properties of that matter (density, phase, etc). Since atoms and molecules are just obeying ordinary quantum mechanical principles, you could in theory simulate any system and use the simulation to derive approximate equations of state, or you could attempt to derive an analytical model (essentially, no simulation, just "math out" an equation from first principles). People try this. It's hard. Realistic systems are too complicated, generally, to either accurately simulate or derive anything completely analytically. So approximations are made. That is, the imagined system is simplified. If you do a Google Scholar search for "primitive model of water" you will find many papers on attempts to derive usually portions of the phase diagram, but it's about more than just water/ice/vapor - the goal is to know all of the physical properties in a given condition. Someguy1221 (talk) 00:10, 12 July 2019 (UTC)

To focus on one area that gets particularly wierd, the materials where the solid/liquid line points up and to the left, which are the materials where the solid floats in the liquid (ice, Plutonium, Bismuth, Germanium, Gallium, and Silicon (but apparently not antimony). I've never seen any sort of calculations which group all of these materials together, and if there are, I doubt the reasons for ice and Plutonium are quite the same.Naraht (talk) 16:55, 12 July 2019 (UTC)