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March 3

CMB is remained from past age of universe or recent

  I have  three difficulties  in cosmology :
    1.in the case so we really judge about the world , then what means just now in our universe ?
    2. rotation mode of galaxy members , why we believe both orbital rotation of galaxy members and stability of galaxy shape and arms?
    3.  Either it is so that CMB is recent thermal Image of universe or it refers  very past time when world age was 380000 years?--Akbarmohammadzade (talk) 09:43, 3 March 2018 (UTC)[reply]

1. We count time in cosmology using our reference frame as determined on earth. So that means that we are not moving at close to the speed of light compared to the rest of the universe. Barycentric Coordinate Time can be used, which cuts out gravitational time dilation of the Earth and Sun. In the past cosmology still described the known universe. So centuries ago, Earth and planets made up a much bigger component. If you see time as "Before Present", it means before 1 January 1950, so you could say that "now" is that date. To read more about "now" see Present, the stub Cosmic time or the more useful Chronology of the universe

2.Our article mentioning spiral arm fails to say much at all. See also Scutum–Centaurus Arm and Perseus Arm and Orion Arm. But these do not mention how they were discovered or anything about long. term stability. The arms are probably due to density waves in the gas, resulting in star formation, with bright new big stars marking the arms. Graeme Bartlett (talk) 11:20, 3 March 2018 (UTC)[reply]

3.Cosmic microwave background is believed to be ancient light. Graeme Bartlett (talk) 11:20, 3 March 2018 (UTC)[reply]

Eyelid anatomy

What is the name for the small flesh colored bump that can be seen on the the inside edge of the far corner of the eye (lateral commissure) when you pull the eye lid away from the eye horizontally? This http://slideplayer.com/8275868/25/images/3/%28a%29+Surface+anatomy+of+the+right+eye.jpg is the most detailed chart I could find but only shows the outer portion --User777123 (talk) 18:19, 3 March 2018 (UTC)[reply]

Do you mean the Canthus? Our article doesn't say much about it, but perhaps that's because there isn't much to say. Dbfirs 21:42, 3 March 2018 (UTC)[reply]

It is near where the canthus is, but that is not it. It is a small bump seen on the inside edge of the lateral canthis.--User777123 (talk) 23:20, 3 March 2018 (UTC)[reply]

How laser printer drums work

In a laser printer (and similar printing devices), a laser 'writes' the image on a drum, that gets electrostatically charged on the spots to be printed. These get covered with toner that gets melted onto the paper.

The drum is covered with selenium or a polymer that can be electrostatically charged.

The question is why does the electrostatically charged spot hold its charge? Why doesn't the charge spread over the whole drum, defeating its purpose? Is that the normal behaviour of an electrostatic charge? What if you have lots of charges concentrated in a small spot and none around? Wouldn't these be pushed away? --Doroletho (talk) 22:26, 3 March 2018 (UTC)[reply]

Your description is not quite correct. The full surface of the drum is charged negatively. But it is covered by a semiconductor that is not (very) conductive under normal condition. The laser is adding energy to the parts of the drum not to be printed. The added energy allows electrons to move more freely (see photoconductivity), thus the negative charge can flow away from just the light-exposed spots, but remains on the others. --Stephan Schulz (talk) 22:56, 3 March 2018 (UTC)[reply]

In the dark state selenium will be an insulator, so electric charge will stay where it is. The light changes the selenium into a conductive state, so that those electrons escape from the surface. Graeme Bartlett (talk) 23:10, 3 March 2018 (UTC)[reply]

March 4

Metronidazole

Is metronidazole effective against Staphylococcus aureus or streptococcus pyogenes?--User777123 (talk) 05:46, 4 March 2018 (UTC)[reply]

We can't give medical advice but you might try a web search. Better yet, ask your doctor. Be aware of the widespread existence of MRSA in some environments, so any particular case might be resistant to whatever. 173.228.123.121 (talk) 09:59, 4 March 2018 (UTC)[reply]

Would MRSA be resistant to malacidins too??? 2601:646:8E01:7E0B:59E2:B6:A6B8:FAC7 (talk) 10:16, 4 March 2018 (UTC)[reply]

Did you read the article you linked to? It seems to answer the general case, bearing in mind they are very recently discovered. Nil Einne (talk) 10:41, 4 March 2018 (UTC)[reply]

This was a rhetorical question, in response to the statement that MRSA is "resistant to whatever". 2601:646:8E01:7E0B:59E2:B6:A6B8:FAC7 (talk) 03:42, 5 March 2018 (UTC)[reply]

But malacidins are not yet a functional antibiotic for humans. Actually they're a long way off it. Staphylococcus aureus and Streptococcus pyogenes probably aren't resistant to to 100000K temperatures either. The relevance of this to either the OP question, or 173's point is unclear even if 100000K is technically 'whatever'. Maybe 'whatever' was poorly expressed, still the point is a relevant one. If you did want to nitpick, a much more relevant issue is that MRSA only describes one type of drug resistance namely to beta-lactam antibiotics of which metronidazole is not. The OP's basic point namely that any particular bacteria could be resistant to Metronidazole, or whatever other antibiotic you throw at them, even if that species of bacteria is normally susceptible is still right. But there's no reason to assume MRSA are going to be. Nil Einne (talk) 08:54, 5 March 2018 (UTC)[reply]

I wonder about the current state of teixobactin. There were some clinical trials announced a few years ago but a quick web search doesn't turn up any news since then. The isolation chip was touted as a means of high-volume discovery of lots of new drugs but I haven't heard anything more coming out of that either. 173.228.123.121 (talk) 17:28, 4 March 2018 (UTC)[reply]

Are you sure? Our article suggests the discovery was only announced in 2015. It seems very unlikely that there would be clinical trials announced 'a few years ago' or frankly even 3 years from now given that. This from 2017 [1] and this also from 2017 [2] also support that view. The last source BTW has info on antibiotics that are in a late stage of development. The most I find from searching is insanely optimistic predictions of clinical trials in a couple of years when it was announced in 2015, which suggests whoever said either had no idea how drug development works, or was just trying to get headlines and didn't care that what they were saying was nonsense. (Not surprisingly, it still remained 'a couple of years' away in media reports in late 2016 [3].) Meanwhile in the real world less than a month ago, a company [4] is announcing they got $3 million for 3 years for pre-clinical development. Nil Einne (talk) 08:32, 5 March 2018 (UTC)[reply]

Metronidazole is not effective against aerobic bacteria like Staphylococcus aureus or streptococcus pyogenes. Ruslik_Zero 20:41, 4 March 2018 (UTC)[reply]

regarding LS coupling vs jj coupling

In very heavy atoms (e.g., Hg), LS coupling dominates over the interactions between Ls & Ss momenta, leading to the change in the way they are summed up to obtain their resultant. Namely, instead of combining individual L & S seperately 1st, followed by combining the total L & total S to get J, we combine each individual pair of L & Ss, and then getting J by combining the respective sums of Ls & Ss . My question is why the way we join up the momentum vectors depends on what interaction takes over, and how. I've some more questions with respect to this issue, subtler ones, but they'll wait to later. בנצי (talk) 12:50, 4 March 2018 (UTC)[reply]

It depends on the strength of spin-orbit interaction: if it is weak as in light atoms then use LS coupling if it is strong as in heavy atoms then use jj-coupling. Ruslik_Zero 20:53, 6 March 2018 (UTC)[reply]

I know that - it shows clearly from the content of my question, with details. What I'm asking is why the domination dictates the way we add together the angular momenta ? In other words, why, e.g., in the case of light atoms, we have to add all the Ls & all the Ss respectively, and then combine the totals of L & S ? It is to do with the the stronger electric interaction between the various Ls & the various Ss respectively, than the magnetic interaction between Ls and Ss. BUT WHAT'S THE REASON THIS ORDER OF SUMMING UP (as an instance) IS RELATED TO STRONGER LS COUPLING ? בנצי (talk) 12:30, 7 March 2018 (UTC)[reply]

Objects with their full atom components list

I'm looking for a list of some everyday life things which are solid and visible microscopically (such as stone, sand, etc.) and to know what atoms they are made of. I found a list of salt or glucose or other fluid substances and I'd like to use more common or solid things. 93.126.116.89 (talk) 15:20, 4 March 2018 (UTC)[reply]

Sucrose. --OuroborosCobra (talk) 16:23, 4 March 2018 (UTC)[reply]

Most of these things are mixtures, and could be a variety of different substances. Sand is mostly made from quartz, and if you look at that article you will see it is made of silicon and oxygen. Yellow sand often contains feldspar, which is more complicated, with silicon and oxygen, and also aluminium, potassium, sodium, and calcium. But some sand is made from broken coral or shells, and then is calcium carbonate, with ... calcium and carbon and oxygen. So it is quite different. A common theme though is that they contain oxygen. Rocks also contain similar kinds of atoms. Darker rocks like basalt might contain Pyroxene, Amphibole, or olivine which also contain magnesium and iron. You may also be interested in Abundance of the chemical elements which asks the other direction, how much of each kind of atom is there in different things. Graeme Bartlett (talk) 22:29, 4 March 2018 (UTC)[reply]

At what tolerances? Parts per million? Parts per billion? Parts per trillion? Nothing you run into is scrupulously pure; so you need to say "what is the lower limit where I'm going to consider some impurity insignificant?" --Jayron 32 23:43, 4 March 2018 (UTC)[reply]

"Neutral" oils

In the first sentence of the oil article, the word "neutral" is used to describe oils in general, as though it was a defining characteristic. What does this mean? Does it have any scientific meaning?

If not, we should take it out. -- The Anome (talk) 15:51, 4 March 2018 (UTC)[reply]

I think it means that it's not an acid or a base. I.e. the pH is 7 (neutral). 173.228.123.121 (talk) 17:00, 4 March 2018 (UTC)[reply]

There's no inherent reason that oils need to be pH neutral, their side chains can have varying pKas. Also, it's not very relevant to describe the acid or base neutrality of oils, since that only comes into play if they are in a solution with water. --OuroborosCobra (talk) 17:12, 4 March 2018 (UTC)[reply]

That's what I thought. I will take the word "neutral" out. -- The Anome (talk) 17:14, 4 March 2018 (UTC)[reply]

I'd guess maybe neutrally charged? --OuroborosCobra (talk) 00:16, 5 March 2018 (UTC)[reply]

I also took it to mean neutrally charged. Perhaps this is meant to disclude lipid sulfates and the like. Someguy1221 (talk) 01:51, 5 March 2018 (UTC)[reply]

Or soaps. --OuroborosCobra (talk) 06:01, 5 March 2018 (UTC)[reply]

The article also says non-polar though. Nil Einne (talk) 08:06, 5 March 2018 (UTC)[reply]

The Anome, It sounds like there still might be something to this. I suggest bringing the issue up on the article talk page. 173.228.123.121 (talk) 19:33, 5 March 2018 (UTC)[reply]

March 5

Shocking... positively shocking

In case of electric shock through water (e.g. an electric heater thrown into a bathtub), by what factor does the current through the body increase compared to an electric shock through dry skin (e.g. from touching some electrified steel bars in a bank vault), assuming that the voltage is the same in both cases? 2601:646:8E01:7E0B:59E2:B6:A6B8:FAC7 (talk) 03:54, 5 March 2018 (UTC)[reply]

this source gives a value of 300 ohms "total body resistance" during immersion in water. But note, this is not a trivial thing to measure, will vary between situations, and it's not trivial to predict the consequence of being exposed to current while immersed in water. But that aside, there's a figure for you. In that same article, resistance for dry callused skin on the hand is given as up to 100,000 ohms. Naively you'd take that information and predict that in dry conditions, you take 333 times less current through your body. That's probably true given the right conditions. The same article also goes into detail however, how the naive assumptions are wrong. The resistance of human skin to current is actually a pretty weird thing to measure, for multiple reasons. Firstly, human skin acts like a capacitor in some circumstances, with the result that current can actually flow nicely through skin when exposed to a source of rapidly changing voltage. Secondly, high voltage can cause biological structures in the skin to break down, which actually changes the skin's conductance. So long story short, assuming the dry person and the wet person are exposed to the same voltage, the electric shock could be anything from orders of magnitude different, to basically the same, depending on the particulars. Someguy1221 (talk) 06:23, 5 March 2018 (UTC)[reply]

Well, for me a ballpark figure would do -- the reason why I'm asking is that, among my many other projects, I'm doing some initial concept work for a James Bond-themed FPS computer game, and I want to have a general idea of how much more damage should electricity cause in water vs. in dry conditions. So, given the figure above, I guess I should make any electrocution while in water instantly fatal, given that I've already decided that touching ~~750~~ 1000 volts or higher will be instantly fatal (lower voltages causing proportionately lower damage, 220 volts causing 32 22 points of damage for example) -- am I right? 2601:646:8E01:7E0B:71B8:6856:E929:5E71 (talk) 09:18, 5 March 2018 (UTC)[reply]

Like so many fatal electric shock circumstances, the situations you describe are such a hazard not because of the live conductor, but because of the unusually low impedance of the earth path.

It's common to think "Don't touch the live conductor", but in fact we do often do this, and survive. It is very common in fatal accidents for someone connected with it to say, "Yes, we always used to get a bit of a tingle from that switch, but we didn't think about it." Then one day, someone touches it with bare or wet feet (and so a better contact to the floor) and they receive a serious or fatal shock. The involvement of water in particular is why there is so much additional care taken (UK regulations at least) for electrical work around bathrooms and kitchens (as a Brit looking at US wiring, I'm just amazed they aren't all dead yet).

A "typical human" is an a moderate-resistance insulating bag of conductive salt water. In a safe condition, we touch properly insulated things. In a fault condition those manufactured insulators have failed and we're relying on the resistance of our skin (the insides are very conductive and nothing will stop that). Anything we do to reduce the skin resistance is what makes a shock into a death. So wet hands, or a piercing of the skin, and especially wet feet (the earth path is usually the more difficult path to make conductive) is bad news.

Bathtubs are earthed (through the pipes, if nothing else) and a body in such a large skin area of water has a low impedance to earth - so, fatal shocks. In some cases though, people have survived the "toaster in the bathtub" scenario simply because the bath is so conductive - if the tub is a large copper one, with the toaster at one end, close to the tub and the body some distance away from it, the current flowing directly from toaster to bath is so high that it trips some further safety device (look into "RCD" devices) before serious injury takes place. Many bathtubs are insulators and although the plughole fittings are enough to give them the same low impedance, a toaster at the tap end might be survivable when the same toaster at the far end of the bath would not be - current flow through slightly conductive water is complicated and the risk depends on just where the body is in relation to the path.

Most electric security fences, for this reason, use a bipole system, not a dipole. Alternate wires are electrified at opposite polarities - so the hazard current is between wires, down a low impedance metallic path. In contrast, animal control fences use a single conductor (for cost) and rely on an earth return through hooves and the ground. As those are high voltage, but restricted current (and pulsed too), the earth return is workable - although most of the shocking voltage is across the earth, not the animal. It's only too noticeable that a shock from such a fence is startling more than painful, but not if you're close to the ground electrode (where the earth impedance is low and most of the voltage would then be across you).

For the harm aspects of electrocution, it's important to understand the relationships between voltage, current and time - also AC vs DC circuits. A really high voltage will cause arcing and burning. A middling voltage will, if the circuit impedance is low, give a large current that can be damaging ("It's the Volts that jolts, it's the Mills (Milliamperes) that kills") - particularly for a cross-body or through-the-heart shock. Especially as the heart is normally electrically self-controlled and applying a voltage across it may cause fibrillation (if used properly, the de-fibrillation effect can be medically useful). A low voltage, especially DC, can also kill, if it's sustained for long enough and the effect is to contract enough muscles to stop you breathing. DC is bad because it tends to make muscles tense in one direction and stay there, whilst AC does the Ian Curtis dance and although you might be injured in the resultant stage diving, at least you don't hang onto the conductor like a dead sloth. There's also the rare example of super-low voltage electrocution, which is only found in submariners, electroplaters and telephone exchange engineers. Even a 2V lead-acid battery can, if big enough, deliver a fatal current. Andy Dingley (talk) 10:35, 5 March 2018 (UTC)[reply]

I assume that in a real-life scenario, if you throw an electric heater into a bathtub, the circuit breakers would trip or fuses blow. And wouldn't be a "fatal electric shock circumstance." I wouldn't test this although. Hofhof (talk) 13:42, 5 March 2018 (UTC)[reply]

The circuit breaker might take a long time to trip or might not trip at all, since tap water is not all that conductive and a. 15 amp breaker takes way more than 15 amps to trip quickly. Caution:Don’t try this at home! A utility I worked at used a salt bucket as a current limiting device a galvanized steel bucket was connected to the system electrical ground connection and filled with water. A copper paddle with a wooden handle was connected to 120 v ac and held with a hand clad with an approved rubber glove and leather outer glove. Some table salt had to be dissolved in the water to get significant current to flow when the copper rectangle ( perhaps 5 inches by 7 inches ) was lowered into the water. With some salt in the water the current was enough to boil the water near the paddle and trip an overcurrent relay ( several amps). This chancy device was retired in favor of safer resistive load boxes (akin to electric toaster).Edison (talk) 17:54, 5 March 2018 (UTC)[reply]

See liquid rheostat. The scary ones were the ones used on early electric locomotives! Andy Dingley (talk) 23:35, 5 March 2018 (UTC)[reply]

The fuses are unlikely to blow. This is an electric heater, which is a high power device, usually designed for the limit of practical use. In the UK, it would be fused at 13A and would be a 2kW or 3kW device. The situation is also an earth fault, which is of higher impedance than the normal connection. The over-current fuse might blow if you stuck a fork into the heater and touched the case, but a conduction path through water is unlikely to do it.

What's a "circuit breaker"? Again, like the fuse, an over-current breaker is unlikely to trip. Instead if it's a specific type of circuit breaker, an RCD, then it might trip in time to save you. However the fault current an RCD can pass by design (to avoid nuisance tripping) is generally higher than a safe current limit - especially on a general supply circuit. If you do have equipment in a bathroom (UK practice seriously discourages this), it's usual to provide a lower tripping current and faster acting RCD for such a situation. Andy Dingley (talk) 23:43, 5 March 2018 (UTC)[reply]

I’m surprised you are unfamiliar with “circuit breakers” but fortunately we have an article about them. Edison (talk) 22:41, 7 March 2018 (UTC)[reply]

It seems clear that Andy Dingley knows what about circuit breakers, their point is the term is imprecise since it can mean different things. Nil Einne (talk) 02:00, 8 March 2018 (UTC)[reply]

One minor point. "Bathtubs are earthed (through the pipes, if nothing else)" is not necessarily true. The faucets are normally above the tubs, and at least where I live, drain pipes are now commonly made of plastic. --69.159.62.113 (talk) 08:37, 7 March 2018 (UTC)[reply]

The requirements and practice for deliberately earthing bathtubs have changed over the years, and for the last forty (at least) there has been a strong requirement that this is done by added protective conductors (wires clamped on). Before this, tubs were metal and so were water supply pipes, so there was a fairly good, although accidental, earth connection.

In the '60s and '70s, there was a shift to plastic tubs and plastic wastepipes. The taps were still strongly earthed and there was a period when these "toaster in the bath" accidents were caused by this. Once again, the bather was already in contact with the live supply (usually a radio near the edge of the bath), yet unharmed, and it was when they reached out and touched the earthed tap to run a bit more water that they received a serious shock. The increasing use of plastic meant that a specific earth conductor and equipotential bonding was needed in baths and kitchens - especially kitchens, as sinks are still largely stainless steel. Equipotential bonding is not the same as earthing (although it can be part of it), as it has conductive things connected together, but not necessarily earthed. However it does mean that there won't be a dangerous condition where one metal thing becomes accidentally live, then there's a dangerous shock on touching another which was accidentally earthed.

Plastic supply pipes are now coming into common use, rather than copper, but water is still enough of a conductor that it could be a shock hazard as an earth return. Andy Dingley (talk) 10:37, 7 March 2018 (UTC)[reply]

Winds and fire

While fueling a fire by bringing fresh oxygen, a strong wind would also tend to extinguish it, by analogy of birthday candles. How one can measure the associated balance of oxygen vs extinguishing, possibly in terms of wind speed required to offset the oxygen intake and extinguish the fire? 212.180.235.46 (talk) —Preceding undated comment added 16:08, 5 March 2018 (UTC)[reply]

In the real-world scenarios, wind generally serves to spread fire. Here's [5] a nice research paper that describes how wind velocity and other variables affect fire spread. One situation where wind can help extinguish fires is when the fuel load is light and there is not much mass burning. E.g. this[6] research paper on grass fire modeling indicates that they can sometimes be put out by very high winds. Fire modeling is a very complicated and complex field; there are few (if any) general laws, and much is still not well understood. A lot of the research is still confined to very specific questions and applications: e.g. here [7] is an interesting study of the effectiveness of using vortex rings to extinguish fires in oil and gas wells. This is all about fires much larger than a birthday candle. I am not aware of any work regarding calculation of wind speed necessary to extinguish such small fire, but perhaps someone else can shed some light on that! SemanticMantis (talk) 16:34, 5 March 2018 (UTC)[reply]

Read Firestorm. There is no typical balance since fires are very different depending on energy source and scenario. Almost all firefighting strategies aim at cutting off the supply of Oxygen. The few situations where its better to extinglish the fire by cutting off the flame manually its usually done with explosives. For that read our article about Red Adair. --Kharon (talk) 17:02, 5 March 2018 (UTC)[reply]

Note that if you don't blow hard enough, the candles won't go out. ←Baseball Bugs ^{What's up, Doc?} carrots→ 21:12, 6 March 2018 (UTC)[reply]

Or even if they do, they might not stay out. DMacks (talk) 21:26, 6 March 2018 (UTC)[reply]

From what kind of soda glass was made in the ancient time?

I looked for the way the glass was made in the ancient time and I found this site which states "Glass is produced from a mixture of silica-sand, lime and soda". What kind of soda it was? and how did they make it? 93.126.116.89 (talk) 17:20, 5 March 2018 (UTC)[reply]

"Roman glass was made from the melting of sand and natron – mineral soda – from the Wadi Natron in Egypt", from Ancient_glass_trade. More info at History_of_glass, which says "The alkali of Syrian and Egyptian glass was soda ash, sodium carbonate, which can be extracted from the ashes of many plants, notably halophile seashore plants: (see saltwort)." See also Sodium_carbonate#Occurrence_as_natural_mineral. It would seem some ancient glass was made with mined mineral soda ash, while other ancient glass was made using plant-derived soda ash. SemanticMantis (talk) 17:34, 5 March 2018 (UTC)[reply]

What is the reason that it's not recommended to "mix" different alcohol drinks?

Always I've been told that it's forbidden to mix different types of alcohol (for example vodka and beer or wine). What is the reason for that? 93.126.116.89 (talk) 18:06, 5 March 2018 (UTC)[reply]

Old saying I learned as a kid: Hard before beer, you are in the clear. Bear before hard, you are in the yard. 209.149.113.5 (talk) 18:46, 5 March 2018 (UTC)[reply]

"Alcohol myth buster: 7) Switching between beer, wine, and spirits will make you more drunk. FALSE: Your blood alcohol content is what determines how drunk you are. Mixing drinks may make you sicker by upsetting your stomach, but not more intoxicated". UK National Health Service Alansplodge (talk) 19:07, 5 March 2018 (UTC)[reply]

Old British saying: "Cider on [i.e. after] beer makes you feel queer, beer on cider, nothing finer." Note that in Britain, "cider" is always alcoholic, so we don't use the term "hard cider" (in 45 years of drinking I've never seen a so-called "soft cider"), and is often stronger than the average beer. {The poster formerly known as 87.81.230.195} 90.211.131.202 (talk) 19:49, 5 March 2018 (UTC)[reply]

I'm pretty sure Alanspoldge has provided a reasonable reference to read indicating it is likely false. Continuing to insist that it is true, absent a competing reliable source, isn't useful. --Jayron 32 20:58, 5 March 2018 (UTC)[reply]

I don't see anyone insisting on anything Jayron. DuncanHill (talk) 23:44, 5 March 2018 (UTC)[reply]

NHS (via AlanSplodge): ". . . Mixing drinks may make you sicker by upsetting your stomach, but not more intoxicated."

British saying I quoted: ". . . makes you feel queer . . . ". "Feel queer" means feel ill, not "be drunker." {The poster formerly known as 87.81.230.195} 90.211.131.202 (talk) 12:37, 6 March 2018 (UTC)[reply]

But then again, "Whisky on beer, never fear; beer on whisky, very risky." (common in the UK)

Much depends on the relative strengths of the two, and on the habits of the drinker. In UK drinking practice, whisky after beer is more commonly the habit of a fairly moderate drinker. Beer on whisky though is unusual, unless you're seeking to get drunk in a serious manner. Also "drinking beer" in the UK would be seen as drinking several pints of British beer, quite possibly double figures, which is an alcohol content comparable to the whole of Milwaukee. Andy Dingley (talk) 23:54, 5 March 2018 (UTC)[reply]

Drinking whisky with beer (i.e. alternating sips) is a common practice in Scotland, where the combination is known as a "hof an' hof" (i.e. a half and half). Note however that Scotch whisky is essentially distilled beer, so this is not really mixing in the same way that combining beer with wine or cider is. {The poster formerly known as 87.81.230.195} 90.211.131.202 (talk) 12:37, 6 March 2018 (UTC)[reply]

There are lots of cocktails made by mixing hard liquor with beer or wine, see for example the famous boilermaker (beer cocktail). Looie496 (talk) 20:04, 5 March 2018 (UTC)[reply]

My favourite is the Dog's nose, where a single or double gin is added to a pint of porter or stout. For historical authenticity (as drunk by the 18th-century Bow Street Runners), one should first mull the porter (a microwave can substitute for a red-hot poker), then sprinkle some finely grated nutmeg on top, then add the gin. It's a wonderful 'winter warmer', but I'd never drink more than one. {The poster formerly known as 87.81.230.195} 90.211.131.202 (talk) 12:37, 6 March 2018 (UTC)[reply]

Could it be that taking two types of alcohol is harder on the liver too, even if you don't get more intoxicated? Hofhof (talk) 22:34, 5 March 2018 (UTC)[reply]

I suppose it could be. The body is pretty complicated and all sorts of weird things can happen. But I can't think of any reason to think it is harder on the liver. Do you have a reason to think that? --Trovatore (talk) 22:56, 5 March 2018 (UTC)[reply]

If you're drinking "two types" of alcohol (such that your liver cares) then the second is likely to be methanol, which is well known for making you sick, blind, mad and dead in that order.

There are many other things in an "alcoholic drink", some of which are well known for causing various upsets. Not many of them involve the liver. Andy Dingley (talk) 23:54, 5 March 2018 (UTC)[reply]

If you have a variety of drinks, you are likely to have more in total, than if you just had one kind. Graeme Bartlett (talk) 23:52, 5 March 2018 (UTC)[reply]

Bingo! I think you nailed it. --Stephan Schulz (talk) 09:35, 6 March 2018 (UTC)[reply]

Only problem is that the claim is that the order of the drinks matters. Hofhof (talk) 13:32, 6 March 2018 (UTC)[reply]

The question, as stated, is anecdotal evidence with poor experimental design. It's inconclusive either way.

There are two hypotheses put forward here, which aren't contradictory, and both of which fit the claim and the observed data.

1. Total alcohol content, not order of consumption, is what matters.

2. There are other social effects, such that the order of consumption is also correlated (but not physiologically causative) with quantity.

Andy Dingley (talk) 14:11, 6 March 2018 (UTC)[reply]

One thing that may be relevant in some circumstances is that the human digestive tract absorbs alcohol fastest at 20% alcohol + 80% water mixture. So if you consume a mix of a low alcohol drink (or even water) and hard liquor it can give a steeper path to intoxication than just hard liquor. 91.155.192.188 (talk) 14:27, 6 March 2018 (UTC)[reply]

I heard it as "liquor before beer, you're in the clear; beer before liquor, never been sicker." The explanation I've heard is based on rate of consumption. If one first establishes the pace of drinking hard alcohol, one is sipping a relatively small volume over time or is drinking a quick shot but only occasionally. Keeping up that pace switching to something with less alcohol content means you slow down the rate of alcohol consumtion. But if instead you start by drinking a lower-alcohol beer, you're drinking at a faster volume pace. Switching to a higher alcohol content means you need to suddently slow down the volum pace to keep from suddenly jumping to a higher alcohol pace, and need to do so at a time when your judgement might already be impaired. Though chasing a sipped mixed drink with a power hour sure confounds things. DMacks (talk) 14:49, 6 March 2018 (UTC)[reply]

Somebody (not me, because that would be original research) feels that mixing wine with almost any other alcoholic beverage can upset my (I mean, their) tummy more than just the other alcoholic beverage. That person assures me that alternating tequila and beer is refreshing and benign.Hayttom (talk) 20:30, 6 March 2018 (UTC)[reply]

I had always heard this in relation to nausea rather than drunkenness per se; if we're only talking about biological triggers for emesis, there is room for unexpected biology. But searching up some refs: [8] [9] [10] all I see are guesses no matter which perspective it is taken from. Wnt (talk) 08:49, 7 March 2018 (UTC)[reply]

March 6

earthing

is there a way to test if something (a washing machine, say) is earthed properly (or at all)? Can I just measure the resistance between PE (earth clips, it's a Schuko type outlet and plug) and some exposed metal part with a DMM? I did mine and it was something like 700 Ohms - that's not ok, it should be very low, should it? 78.50.151.26 (talk) 17:04, 6 March 2018 (UTC)[reply]

Here is a basic outline on how to test if something is properly earthed (grounded in AmEng). --Jayron 32 17:09, 6 March 2018 (UTC)[reply]

That's not the same thing. That article is about testing the fixed premises wiring, not the appliance. Andy Dingley (talk) 21:52, 6 March 2018 (UTC)[reply]

This is meant to be done with a dedicated earth continuity tester, that can inject 10s of Amps, and measure the voltage rise. They are commonly called Meggas, after the company that makes them. We don't seem to have an article on the device, or the company. LongHairedFop (talk) 21:49, 6 March 2018 (UTC)[reply]

"Meggers" aren't the earth impedance testers, but the high resistance insulation testers. We could certainly use an article on them, although we do have one on the company. Andy Dingley (talk) 21:51, 6 March 2018 (UTC)[reply]

I don't know German domestic regulations, but in the UK this would be part of portable appliance testing, usually known tautologically as 'PAT testing'. A quick guide to the requirements for it. A detailed guide to how to organise testing in a business, (requires sign-up). This is normally outsourced to the innumerable 'cottage industry' PAT testers: it costs a few hundred for a few days' course, a few hundred more for a test machine and then almost anyone can set themselves up as such a service. Cost of having a test done mostly depends on the number of items to test in a day: per-item costs are cheap when doing a whole office, but a call-out charge to test one item is a whole call-out charge.

Technically, the requirements are in here: Code of Practice for In-service Inspection and Testing of Electrical Equipment (4th ed.). IET. 2012. ISBN 978-1-84919-626-0. Very simplified, the steps are:

Visual check for damage
Earth continuity test (low impedance measurement from the plug earth to the case)
Insulation resistance test (high impedance Megger test from Live & Neutral pins of the plug (connected together) to the Earth pin
Leakage current test (high impedance test from Live & Neutral to the case) - this may involve a high voltage 'flash' test.
Functional check

It's not necessary to use a specific PAT tester instrument for this, although it does need properly calibrated instruments, one of which is a Megger, a high-voltage resistance meter and many tests need to be carried out at current which aren't those that a normal ohmmeter works at. PAT testers are much quicker for bulk testing though. Competent PAT testing does need more than just "poking at it a bit with a Megger" though.

For your washing machine, the first thing is to eyeball check it for what's wrong - it should have an earthed cable with a clear earth connection to the case, just inside the cable entrance. If this is still connected, then I'd strongly expect that the cable or plug has a broken earth connection. Then do a continuity test [11] [12] where you need a fractional ohm ohmmeter that can use a high testing current. This current can be 20-200mA for one testing method, or as much as 25A for an appliance like a washing machine (this is why a PAT tester is often needed, as there aren't many other test instruments which can do this easily). The earth resistance must be no more than 0.1Ω (for the connection to the case), plus an allowance (usually even less than this 0.1Ω) for the cable resistance. [I'm not going to re-state the rest of PAT testing]

Your washing machine is a simple device, earthing wise. So I'd expect to be able to get the loop impedance right by no more than just looking at that one connection and probably swapping a damaged cable. Andy Dingley (talk) 21:50, 6 March 2018 (UTC)[reply]

Frozen-thawed eggs - yolks remained solid

I froze and later thawed some whole eggs and when I cracked them open, all three yolks were solid (they'd thawed over 12 hours at ~20 °C so they weren't still frozen). Was this caused by the freeze-thawing? — Preceding unsigned comment added by 185.222.219.151 (talk) 22:41, 6 March 2018 (UTC)[reply]

[F]reezing yolks for future use is problematic. The water they contain forms ice crystals, causing their proteins to cluster together in tight groups that don’t easily come apart, even once the yolks return to room temperature. The result: yolks that remain solid even after thawing and produce baked goods with hard, gelatinous flecks.

"Freezing Egg Yolks". www.cooksillustrated.com.

See also: "Freezing Eggs". Eggcyclopedia. Incredible Egg. —2606:A000:4C0C:E200:1D14:5B23:6FC6:8569 (talk) 00:22, 7 March 2018 (UTC)[reply]

March 7

A case study of a male with anorexia nervosa and low testosterone levels.

Could anyone help me find the full text of this pubmed article? Thanks for your time and help! 60.54.122.164 (talk) 08:12, 7 March 2018 (UTC)[reply]

If you really need a copy of a scientific article and don't want to pay for it, shoot the main author an email and ssk for a "reprint". But for something that old, you may have to go to a nearby university library and look on microfiche. Abductive (reasoning) 09:18, 7 March 2018 (UTC)[reply]
There's a Wikipedia project called Wikipedia:WikiProject Resource Exchange/Resource Request that lets you ask other Wikipedians for copies of references they may have access to but you don't. I would try there. --Jayron 32 13:26, 7 March 2018 (UTC)[reply]

Imagine the temerity of coming to the reference desk looking for a reference! Matt Deres (talk) 14:53, 7 March 2018 (UTC) [reply]

I think Abductive is right that the big problem here is it possibly just isn't online. The Journals own archives only go back to 1996 [13]. I had a look at it doesn't look like Jstor has archives and I couldn't find anyone else with them. I looked at the University of Auckland database, obviously not the most extensive in the world although they do have a medical school, and they only seem to have the official journal (including archives back to 1996) for online access. Further back to 1978 you will need to get access to the printed journal. Or make an interloan request. So unless someone has specifically made this particular article available, someone is going to need to scan or digitally photograph some physical version of the original journal. Nil Einne (talk) 01:21, 8 March 2018 (UTC)[reply]

Does the crust thickening over the eons make it easier or harder to break Earth's highest natural point above sea level record?

The Himalayas are too still growing to attempt the record but times when the world's highest point stops rising happen eventually.

2. Are the highest points in Himalaya-style ranges on Pangeas? Sea level is lower then, colliding plates are bigger and more numerous, providing more chances for a mountain to beat the others but Pangeas stop rising when mantle convection switches direction due to continent insulation instead of waiting for the limits of structural strength or plate power so I'm not sure.

3. Or are they/will they be volcanos? Couldn't a shield volcano significantly exceed Mauna Kea volume by having it's plate decelerate and reverse direction a few miles after the hotspot passed? Sagittarian Milky Way (talk) 23:17, 7 March 2018 (UTC)[reply]

To answer 3: Olympus Mons is a Shield volcano on Mars. With its 22 Km height its 2 and a 1/2 times higher than our Mount Everest. In fact most "peaks" on planets and moons in our system are volcanos and given their measure we are probably very lucky on earth, which is roughly twice as big as Mars, not to have a relative copy of Olympus Mons with 44 Km height on earth. --Kharon (talk) 02:02, 8 March 2018 (UTC)[reply]

The highest points are probably under control by glacial erosion. If land gets too high on Earth it will get covered in glaciers, and icecaps, which will grind off the surface rapidly. Some rapidly rising tectonic areas on Earth are under deep river valleys. see River anticlines. Graeme Bartlett (talk) 03:30, 8 March 2018 (UTC)[reply]

So a Greenhouse Earth might have the highest point of at least the Phanerozoic if higher snowline overcomes the higher sea level? Sagittarian Milky Way (talk) 03:55, 8 March 2018 (UTC)[reply]

Yes. Greenhouse conditions will also have more humidity and then condense more on high areas. The monsoon may be heavier with more erosion. This may trigger more uplift adjacent to the big rivers. But also the snow line would then be higher. But if the temperature is so high, as on Venus, there is no condensation of water to liquid or solid, even though it has a similar amount of water vapour as the Earth's atmosphere. This idea would predict tropical areas to have higher topography than polar regions. Graeme Bartlett (talk) 04:24, 8 March 2018 (UTC)[reply]

Most of the earth's highest points are tectonic rather than volcanic in origin, although these are almost all in Asia. The highest active volcano in the world is Ojos del Salado on the borders of Chile and Argentina at 6,893 m, about 2,000 m lower than Everest. The continental collision between the Indian and Eurasian Plates that has produced the Himalayas is not that unusual in Earth's past history, but it would be useless to speculate if the mountains associated with say the Caledonian orogeny were higher - we simply cannot know. Mikenorton (talk) 10:28, 8 March 2018 (UTC)[reply]

So if anyone says the Appalachians or whatever were 30,000 or 33,000 feet that's just unfounded speculation? Sagittarian Milky Way (talk) 10:46, 8 March 2018 (UTC)[reply]

That would be a guess, albeit an educated one no doubt, but insufficient to answer this question in my opinion. Our best guess for the Caledonides is that they were similar in scale to the Himalayas - that's all we can say. Mikenorton (talk) 11:25, 8 March 2018 (UTC)[reply]

March 8

science

properties of different plastic — Preceding unsigned comment added by Amohamed7001 (talk • contribs) 03:18, 8 March 2018 (UTC)[reply]

Did you see Plastic#Properties and classifications? Then you can also look at individual plastics articles like Polyethylene#Properties. Graeme Bartlett (talk) 04:15, 8 March 2018 (UTC)[reply]

Goldfinger

I know that "skin suffocation" is not real and that having your entire body painted gold would not, by itself, kill you; HOWEVER, given that the paint DOES interfere with the body's thermoregulation, in the particular case of Jill Masterson, would it have been plausible for her to die from heatstroke, given that the scene takes place in Miami, which can get very hot and humid? (There has indeed been at least one case, back in Leonardo da Vinci's time, when a boy died after having been painted gold (although the actual cause of his death was hypothermia), which is probably where Fleming got this idea in the first place.) 2601:646:8E01:7E0B:71B8:6856:E929:5E71 (talk) 09:46, 8 March 2018 (UTC)[reply]

Is the question "Is death by gold paint possible?" or "Would Jill Masterson have died if painted?"

You don't need much thermoregulation, even in Florida, to lie still on a bed. Heavy exercise might be another matter. Then the main human method of thermoregulation is sweating, which is an effective paint remover (to see it in action, watch Newportograd-based band musika Rogora Khart performing [14], in whiteface makeup). Humans can also, like hairier mammals such as dogs, regulate by panting. Then, in the Masterson case, the problem is that she's supposed to have lain there passively (a Bond girl's main role) whilst being first painted, then dying - without doing anything about it. Note that (in the book at least) the whole body painting thing is a fetish of Goldfinger's and he does it first with all his women, so it's survivable through exercise. The McGuffin is that "leaving the little patch unpainted" is the difference between survival and developing an unanticipated, fatal heatstroke (which isn't though an unusual prognosis for heatstroke).

So it's not about body painting (neither reality nor story claim the lack of most body thermoregulation would be harmful), it's all about that unpainted patch. Which is pure invention. Also, as with all Bonds, do read the book - they have so much more depth than the films. Andy Dingley (talk) 10:47, 8 March 2018 (UTC)[reply]

So the answer in her case is "probably not"? Thanks! 2601:646:8E01:7E0B:71B8:6856:E929:5E71 (talk) 12:41, 8 March 2018 (UTC)[reply]

[15]. --Jayron 32 12:59, 8 March 2018 (UTC)[reply]

Just in case, I should point out that painting can be lethal if a toxic solvent is used in the paint -- and many solvents that are ordinarily little inconvenience, like toluene, can be fatal with sufficient skin coverage. This isn't relevant to the McGuffin, but a body-painting project should be approached with some caution. Wnt (talk) 15:37, 8 March 2018 (UTC)[reply]

Danger of eating raw eggs

Was salmonella in eggs less common when Rocky ate them raw? Was it more common to eat eggs raw back then? --Hofhof (talk) 18:04, 8 March 2018 (UTC)[reply]

Presuming you mean the first movie, probably less common for the first question. [16] says

Salmonella enteritidis in chicken eggs mysteriously began to appear in many countries at about the same time in the late 1970s and early 1980s. One theory, by Andreas J. Bäumler, a microbiologist at the University of California, Davis, ties the bacterium’s emergence to the virtual eradication of two related strains of salmonella that make chickens sick. Once those strains were stamped out, through culling of infected birds, the theory goes, immunity to similar strains of salmonella decreased. That opened up a niche for enteritidis to thrive.

The first movie was set in 1975, so it was likely at the beginning of this time, if not before. The CDC in the US recommends pasteurised eggs if you don't want to cook them (or only lightly cook them) [17]. These are evidently widely available there. (I don't think pasteurised eggs as opposed egg products are at all common, if they even exist, here in NZ.) Nil Einne (talk) 18:26, 8 March 2018 (UTC)[reply]

BTW, probably not the best source for learning about that kind of thing (I came across it when looking for something else) but this source has some discussion of the various serotypes if you're wondering if it's likely other ones were a big problems with eggs before [18]. Nil Einne (talk) 18:39, 8 March 2018 (UTC)[reply]

See also [19]/[20], [21] & [22]. The history part of the last source in particular seems to support the view that human Salmonella infections from eggs (or chickens) were a lot less common then. Nil Einne (talk) 18:56, 8 March 2018 (UTC)[reply]

Great reference work Nil, thanks! SemanticMantis (talk) 21:23, 8 March 2018 (UTC) [reply]

In The UK, raw eggs were off the menu from Dec 1988 (Salmonella in eggs controversy) until Oct 2017 [23]. --catslash (talk) 13:35, 9 March 2018 (UTC)[reply]

Yes, my read of the sources that in a number of countries definitely including the UK, Salmonella risk from raw eggs peaked sometime in the 80s, 90s, 2000s or maybe 2010s and has been going down since then. I think this includes the US, although the risk still seems relatively high there, but anyway if you are talking about one of the later Rocky movies it may get complicated. Nil Einne (talk) 02:27, 10 March 2018 (UTC)[reply]

What's the next Bayer star to cross an official constellation border by proper motion? What was the previous?

(using the fiction that they've always existed even though the borders are only roughly a century old) Sagittarian Milky Way (talk) 23:54, 8 March 2018 (UTC)[reply]

I don't see an article for Bayer star. What are you talking about? ←Baseball Bugs ^{What's up, Doc?} carrots→ 00:14, 9 March 2018 (UTC)[reply]

See Bayer designation and Table of stars with Bayer designations. Looie496 (talk) 01:57, 9 March 2018 (UTC)[reply]

A star's Bayer designation is also it's most common "name" except for the dim ones in the table with numbers and the very few that link to their names. (i.e. Polaris) Sagittarian Milky Way (talk) 02:42, 9 March 2018 (UTC)[reply]

You will be interested in http://orbitsimulator.com/constellations/constellationProperMotion.html where each constellation has an animation in .gif form and you can see stars moving in and out of constellations. Alpha Centauri crosses very quickly. But some constellations have stars right in a corner, like Andromeda, so these come in or out fast. Hydrus has a star that only entered about 1000 years ago. Graeme Bartlett (talk) 03:32, 9 March 2018 (UTC)[reply]

March 9

Hydramethylnon

Does anyone get this? Our article on hydramethylnon doesn't suggest that it's terribly poisonous (the blue section of the NFPA label is just 1). The image that pops up if you hit the red button says "Did you order a book on how to poison redheads?" but again our article doesn't suggest anything very relevant.

A little searching suggests that hydramethylnon is used to control the meat ant, which seems to have a red head. Is that the joke? --Trovatore (talk) 10:44, 9 March 2018 (UTC)[reply]

Its a "comic" webpage. Why do you expect them to be absolutely seriouse? No idea if they are joking or dont know better. They obviously offer no access to anyone and everyone willing to correct their mistakes like we here. --Kharon (talk) 16:17, 9 March 2018 (UTC)[reply]

I don't expect them to be serious, obviously. I just don't get the joke. Unless it's the bit about the redheaded ant, in which case I don't think it's as funny as Zack usually is. --Trovatore (talk) 19:53, 9 March 2018 (UTC)[reply]

A little extra context: As regular readers of Saturday Morning Breakfast Cereal will recognize, the redhead in the frame is the cartoonist himself, Zach Weinersmith, and the woman is his real-life wife, whose name I can't remember but she may herself have a WP page as a biologist. So it's a my-wife-is-trying-to-get-rid-of-me joke, which is not exactly novel, but if it were done in some clever way I wouldn't mind that. In this case, if it is the thing about the meat ant, then I don't think it's that clever, just obscure. Then the cartoon shoehorns in a completely different point about personalized AI recommendations. Well, no one bats 1.000. But if anyone can come up with a different explanation I'd be interested to hear it. --Trovatore (talk) 20:28, 9 March 2018 (UTC) [reply]

I should also say, it's only because I think really pretty highly of the comic, in general, that this one made me scratch my head and go WTF. I think it's one of the best webcomics out there, maybe the best. Try this one for example. --Trovatore (talk) 20:37, 9 March 2018 (UTC) [reply]

Simón Bolívar and natural history

Natural history#Birth of scientific biology says the following:

The understanding of "Nature" as "an organism and not as a mechanism" can be traced to the writings of Alexander Humboldt (Prussia, 1769–1859). Humboldt's copious writings and research were seminal influences for Charles Darwin, Simone Bolivar, Henry David Thoreau, Ernst Haeckel, and John Muir.

Darwin, Haekel, and Muir were biologists or naturalists, and Thoreau wrote a good deal about nature, but Bolívar? He was a soldier and politician. What did he do that would be influenced by such a perspective? Or should this be taken as an error of some sort? Simón Bolívar (disambiguation)#People lists nobody who would potentially be confused with him and who would be a likely candidate for appearing in this section, and Simone Bolivar doesn't exist. I'm inclined to distrust the statement: it comes from a book, very improperly cited, whose author is a popular writer, not a scholar, and the publisher does literature and other popular writings, not scholarly stuff on history, biology, or history of science or history and philosophy of science. And the poor quality of the citation (and apparent spelling error) make me question whether the person who added this statement were properly capable of interpreting what was in the source in the first place. Nyttend (talk) 12:34, 9 March 2018 (UTC)[reply]

That sentence is false or obscure, for it would probably astonish Bolivar, Humboldt etc to be cited as origins of an idea as ancient as Hylozoism.John Z (talk) 19:05, 9 March 2018 (UTC)[reply]

Bolivar is not being so cited. "Humboldt's copious writings and research were seminal influences for Charles Darwin, Simone Bolivar, Henry David Thoreau, Ernst Haeckel, and John Muir". DuncanHill (talk) 19:19, 9 March 2018 (UTC)[reply]

My point is that any of those people would be astonished to see anyone who had lived so recently so cited. And the article is not on Bolivar, Humboldt or any of the others. It is a sillier anachronism than "The understanding of differential and integral calculus can be traced to Silvanus P. Thompson" At least that's the right millennium.John Z (talk) 01:01, 10 March 2018 (UTC)[reply]

There's a review of the book in Geoscientist (Vol 26, No2, March 2016, page 22) which says, amongst other things, "His range of influences, from Goethe and Simon Bolívar to Darwin, Haeckel, Muir, Emerson and Thoreau, defies belief." The review is by Ted Nield. DuncanHill (talk) 12:43, 9 March 2018 (UTC)[reply]

See also Alexander von Humboldt and Simón Bolívar by J. Fred Rippy and E. R. Brann, The American Historical Review Vol. 52, No. 4 (Jul., 1947), pp. 697-703. DuncanHill (talk) 12:48, 9 March 2018 (UTC)[reply]

A Google search for '"Simon Bolivar" Humboldt' returns many hits. They certainly met, and it seems they certainly discussed politics. DuncanHill (talk) 12:51, 9 March 2018 (UTC)[reply]

And, if you had looked at our article Simón Bolívar you would have read "During this time in Europe, Bolívar met Alexander von Humboldt in Rome. Humboldt later wrote: "I was wrong back then, when I judged him a puerile man, incapable of realizing so grand an ambition." Leopold von Buch, a geologist with little or no interest in politics, came to know Bolívar through Humboldt disliking him immediately". DuncanHill (talk) 12:57, 9 March 2018 (UTC)[reply]

(edit conflict)Just to note that it is not unusual for people from wildly different fields or geographies to have long-distance friendships or to converse with one another. Bolivar was certainly active during the tail end of the Age of Enlightenment; maybe half a generation or so younger than other late enlightenment politicians such as Benjamin Franklin and Thomas Jefferson, both of whom had a keen interest in science, and especially natural history. Our article at Simón Bolívar#Private life notes that he met Humboldt and another scientist, Christian Leopold von Buch, while travelling in Europe to recover emotionally from the death of his wife. It appears that their friendship was late in coming; apparently Humboldt initially disliked him, but later grew to admire him. This source (in Spanish) notes that they traveled together in Italy, and hiked up Vesuvius together, and quotes some of the writings of both men to each other. There's also a Pico Humboldt in Venezuela; one has to wonder if Bolivar had a direct influence on that. --Jayron 32 13:03, 9 March 2018 (UTC)[reply]

(ec)Nyttend, if you wonder what a soldier and politician might learn from Humboldt, you could try reading the articles on Bolivar and Humboldt, and on the Age of Enlightenment. You failed to do even the most basic of research before coming here to be snide about the editor who added the reference, an award winning book and its author, and a major publisher. You really should try harder next time. DuncanHill (talk) 13:10, 9 March 2018 (UTC)[reply]

We also have many other scientist-politicians (even if Bolivar wasn't much of a scientist actually, he did have an interest in it) such as Isaac Newton (who served in Parliament and also took his job as Master of the Mint quite seriously), scientist-solidiers such as Lazare Carnot (from a noted family that also produced many physicists and politicians), etc. The modern world has given us Angela Merkel and Margaret Thatcher (both chemists before entering politics), Grace Hopper (computer scientist and naval officer), etc. The presumption that one could not have such interests in common does seem quite misplaced. --Jayron 32 13:21, 9 March 2018 (UTC)[reply]

It's not just an interest in Humboldt's science, we read in Alexander von Humboldt that "Other scholars counter that Humboldt dedicated large parts of his work to describing the conditions of slaves, indigenous peoples, mixed-race castas, and society in general. He often showed his disgust for the slavery and inhumane conditions in which indigenous peoples and others were treated and he often criticized Spanish colonial policies." The relevance of that for Bolivar hardly needs spelling out, does it? DuncanHill (talk) 13:38, 9 March 2018 (UTC)[reply]

<side discussion moved to talk --Jayron 32 14:52, 9 March 2018 (UTC)>[reply]

March 10

Could Classical Physics Book For A Math Person

I have always been fascinated by physics, but I have a terrible time of learning it - not the mathematics parts, but the way that physics books use mathematics and the physical assumptions that inform on that (which are often unstated). Indeed, I am in a weird position in that I study mathematics and, actually, have an easier time with physics the more removed it gets from day to day life (where things have to be laid out more carefully and clearly for the reader). However, so while I can make my way through a book on quantum physics, on math alone, and skim through the parts that draw directly from classical mechanics, I can't go much beyond this because I don't have a good foundation for the subject. So, does anyone know of any good books on classical mechanics (especially those that get into classical field theory at some point) that are written with math majors in mind? It would be doubly awesome if the book did help develop physical intuition, or an intuition for these subjects as held by physicists. I am not asking for a book that develops the mathematics of classical mechanics, by itself, that isn't especially difficult for me, but for a book that could hold my hand, so to speak, with the physics side of it (and, if possible, doesn't use math tricks without explaining them - even in simple cases where the math clearly works out, several of the books of read seem to just assert results more on the basis that that should be the case than because of any mathematical justification, which makes even basic math feel slippery when paired up with physics to me). **For a specific example, the last such book I tried reading was discussing unit vectors in spherical and cylindrical coordinates, which isn't a difficult concept, but they immediately began to use them without any clarification on why they could use them that way, it was very hand wavy - after sitting down and writing it out a little, it wasn't difficult to follow. The problem here, for me, wasn't that I need to get more comfortable with the math and they were just assuming I was, but that there were physical assumptions about what we were doing that were being used to handwave why you can do this and that; indeed, I would have been more comfortable with skipping steps in a mathematical concept than appeals to why you can treat the dot product a certain way because of work and force. In short, I would love a book that reads more like a math book and builds up from first principles, as much as possible, while explaining the physics that follows from there, rather than the opposite way around. Thank you for any help to this rather ranty and rambling request:-)24.3.61.185 (talk) 10:55, 10 March 2018 (UTC)[reply]