Wikipedia:Reference desk/Archives/Science/2015 February 24

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February 24

Chemical composition of Steam

If I wanted to know if something was burned by steam , and the residue was carbon , what would the exact chemical composition(formula) be if it was tested , and steam or water was the cause or present , for instance if metal or an alloy was extremely hot and cooled down suddenly and shattered and left a carbon residue and was tested what would the chemical formula be does anyone know ??? or apart from everything else will H2O be present no matter what ?? — Preceding unsigned comment added by 165.143.155.57 (talk) 06:40, 24 February 2015 (UTC)

If carbon residue is left by steam, it wasn't steam, it was smoke. Carbon residue means soot is present, and carbon is not water. Steam is gaseous water (H₂O) has no carbon in it. If it leaves carbon, it had carbon to begin with. --Jayron32 12:28, 24 February 2015 (UTC)

You might also want to read about how real-world fire investigation uses forensic evidence to draw conclusions about a catastrophic event. NIST even offers a program on the topic, with several books listed as sources: Disaster and Failure Studies. Nimur (talk) 14:55, 24 February 2015 (UTC)

Is there a maximum time limit to a human courtship?

Courtship explains that in the UK, people court about 2-3 years. This does not mention statistical outliers. In that case, what is the longest human courtship known? 5 years? 10 years? 25 years? 50 years? 140.254.136.182 (talk) 18:47, 24 February 2015 (UTC)

One famous outlier was Michael Winner who married 70-year-old Geraldine Lynton-Edwards when he was 75. They had been courting for 50 years, on and off. Dbfirs 18:56, 24 February 2015 (UTC)

Although he apparently had women in his life - including a prior marriage. Hard to count it as a courtship in the circumstances. Collect (talk) 19:10, 24 February 2015 (UTC)

This might be better asked on the Humanities desk. -- LongHairedFop (talk) 19:26, 24 February 2015 (UTC)

Collect's comment above along with Dbfirs example sort of hinted at this. I think this question (as with many) is basically impossible to answer, unless you come up with a precise and clear definition of courtship. (Well even then it's probably impossible to answer since it's unlikely to be something recorded.)

Our article uses, "Courtship is the period in a couple's relationship which precedes their engagement and marriage, or establishment of an agreed relationship of a more enduring kind. During courtship, a couple get to know each other and decide if there will be an engagement or other such agreement." It also mentions how courtship practices vary significantly.

Consider the example above, they seem to fit within this definition for the 50 years or so, yet a both Dbfirs and Collect hinted at, many wouldn't count the whole thing as courtship.

Or consider if two people meet as young kids, perhaps they become friends. They stay that way for many years. At some stage they realise they have romantic feelings for each other, and begin a dating. Under the definition used in our article, it would seem you should count the time from when they first met, but I think many would only count around the time they began to realise they have feelings.

Yet that isn't simple either. What happens if only one party initially develops feelings, and it takes a long time and a lot of effort before the other party does likewise (probably most such relationships end in disaster but you did ask for outliers)?

Or if you're taking the looser definition, what about if the couple meet as children and then lose touch for many years? What about if they meet and know each other but have only minimal contact?

As for my earlier point of differing practices, on Collect's point, even if not true for the above case, in some cultures polygamous (mostly polygynyous) marriages are acceptable. In such cases it may be acceptable for one partner to be publicly courting another person while already married. Of course in many cultures, publicly courting multiple woman may be acceptable at least at an early stage.

Our article mentions UK averages and also the earlier point "establishment of an agreed relationship of a more enduring kind". In the UK and some other countries, it isn't exactly uncommon for a couple to start cohabitating before even engagement. Are they still courting then?

It definitely doesn't fit many traditional definitions of courtship, even in these countries. Note in some countries, e.g. NZ such a relationship may have legal implications at some stage perhaps being treated very close to a marriage, but will legally never be a marriage without the formal process. And depending on the couple, the engagement and marriage, while perhaps important, may not be that important. (And also sometimes may only come after many years of cohabiting and describing each other as partner or spouse, kids, basically everything you'd expect in marriage except the certificate, except of course marriages themselves existed long before certificates and there are still plenty of places where it isn't necessary for something to be legally considered a marriage. In fact sometimes they may never get married, see my later point.) Yet if you count the cohabiting as the end of courtship, consider some may jump in to this extremely readily, and perhaps even stop doing it due to relationship problems a few times and not really consider their relationship anything that special at least the first time they are cohabiting.

Also are you only counting successful courtship? In other words, if a couple spend a lot of time together developing a romantic relationship but it ultimately doesn't work out, are you counting this or not? Consider if you require a successful marriage proposal, or even a marriage, you're ruling out for example, a case where a couple a courting and one party plans to propose to the other and the other party basically knows and tells several people close to them (and it's clear they will accept), but one of them dies before this can happen. (Or alternatively one person dies before marriage.)

Nil Einne (talk) 20:08, 24 February 2015 (UTC)

I know a couple who were engaged for more than thirty-five years. They were finally married in summer 2014. Not a dry eye in the house, apparently (I wasn't there myself - don't know them that well). RomanSpa (talk) 23:24, 24 February 2015 (UTC)

The second Google hit on longest courtship is from 1915 and says: "The longest courtship on record ... seventy-five years".[1] PrimeHunter (talk) 23:25, 24 February 2015 (UTC)

Note that both RomanSpa's and PrimeHunter's examples further illustrate the point above. In RomanSpa's example, the couple were engaged and I suspect their relationship was not that different before and after marriage, they were simply prevented by the laws of where they lived from being married. While it sounds like their marriage is very important to them and it's rather sad they were forced to wait so long, whether you want to call that period courtship will vary. It doesn't fit the definition from our article (and it would I presume not count in the survey). Conversely many such couples may have never had a formal engagement because they couldn't get married and didn't know when they were going to be able to. Are you going to count one as courtship, and one not, despite the fact the relationships before and after marriage may be similar? In the example mentioned in PrimeHunter's ref, although it calls it courtship, there's mention of how the bridal day was repeatedly deferred and ended up happening when one partner was dying. This suggests there could have been an engagement, or at least there were apparently some sort of specific marriage plans during the courtship. Nil Einne (talk) 16:10, 25 February 2015 (UTC)

I'm suspicious of PrimeHunter's example. It's next to another space-filling item saying that backgammon was invented in 1224, which it wasn't. The same story appears in newspapers as early as 1902, and none of them give the year of the alleged wedding, which is usually not a good sign. -- BenRG (talk) 22:54, 25 February 2015 (UTC)

Growing outside the womb

You know how some species like chickens lay eggs? Well, is it possible to make an artificial "egg" for a human fetus? At birth, will the human fetus have the ability to kick out of the shell? Who will nurture the child when it's born? 140.254.70.33 (talk) 23:04, 24 February 2015 (UTC)

Artificial wombs are an appealing idea, but ... let's be realistic. Infant formula, replacing the seemingly simple nutritional recipe of breast milk, is so laughably deficient that many studies have found the babies to lose 5 or 10 points of IQ from the unwholesome substitution. Breast milk isn't even alive and we fall flat on our face trying to replace it. Much the same can be said of blood substitutes; whenever some group of luckless souls becomes the newest victims of the doctrine of "community consent" to some Frankensteinian experiment at the cellular level, double digits more people die than would have died if given normal blood transfusions. Now imagine that instead of trying to replace a mere fluid, you're trying to replace a living human woman, with many endocrine glands, bone marrow, digestive tract, even the occasional inscrutable but likely vital instinctive call for pickles and ice cream, all responding to the pregnancy. This is an idea that will be proposed ten thousand times but never happen. Wnt (talk) 23:14, 24 February 2015 (UTC)

Can you point me to at least one study that "found the babies to lose 5 or 10 points of IQ from the unwholesome substitution"? Ruslik_Zero 19:14, 25 February 2015 (UTC)

Infant formula#Health risks says: "Some studies have found an association between infant formula and lower cognitive development, including iron supplementation in baby formula being linked to lowered I.Q. and other neurodevelopmental delays; however other studies have found no correlation." You may wish to follow the references given there. -- ToE 16:59, 26 February 2015 (UTC)

What about babies that are breastfed AND cowmilk-fed? Does that decrease IQ? (I was one!) 140.254.70.33 (talk) 23:33, 24 February 2015 (UTC)

Neglecting the hyperbole, the answers to your questions are: No, it is not possible to make an artificial "egg" for a human foetus; No, the child will not have the ability to kick out of the shell, because (a) the shell is likely to have to be fairly thick to hold the amniotic fluid in place, and (b) humans do not have that kind of instinctive kick reaction at the moment of birth; No-one will be needed to nurture any children born in such as way, because nobody is going to be born that way any time soon. Despite the previous comment, it is impossible to permanently rule out this technology, but it is unlikely to happen in the near future. A technology of this kind would certainly save lives (pregnancy carries substantial risks for the mother), but is a long way from being developed. RomanSpa (talk) 23:38, 24 February 2015 (UTC)

Agreed that just because we can't do it now, that doesn't mean we will never be able to do it. After all, we have artificial bone, teeth, and (temporary) skin. That said, this seems similar to the "living head in a jar" concept we often see in sci fi, which presumably is also a long way off. StuRat (talk) 23:57, 24 February 2015 (UTC)

• The OP's question is about an egg, not an artificial decantable. The obvious answer is no. No egg could hold enough nutrients, store enough waste, or pass enough oxygen to carry a baby to term. That's why we have placentas and egg-laying animals don't. Consider the size at which marsupial larvae are born. They are so small because they cannot develop any larger with the support an egg can give. Look at newborn monotremes for the limit for mammals, and keep in mind these are small-brained and relatively cold-blooded mammals. 05:46, 25 February 2015 (UTC)
  • As you imply, the different ways that gestation and birth occur across different species are the result of evolutionary adaptation. In order to bring a human embryo to full term outside the womb, be it in some sort of egg or laboratory device, it would be necessary to recreate all the functionality of the uterus during pregnancy. Obviously, this raises various moral and ethical questions. But forgetting that, trying to achieve it successfully would likely prove a daunting task. ←Baseball Bugs ^{What's up, Doc?} carrots→ 14:21, 25 February 2015 (UTC)