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March 8

Year Span of 485-490 Days

Are there any known planets out there with a year span of 485-490 days ? I ask this because the number of days in a Julian cycle is 4×3651⁄4 = 1461 = 3×487. — 79.113.199.220 (talk) 00:51, 8 March 2017 (UTC)[reply]

Do you mean our Earth days of 24 hours or another planet's number of rotations during its orbit around the sun?--Aspro (talk) 00:59, 8 March 2017 (UTC)[reply]

Initially, I had Earth days in mind, but, now that you've mentioned it, I would be curious about the latter as well. — 79.113.199.220 (talk) 18:47, 8 March 2017 (UTC)[reply]

Not in our solar system. Mars already has 667 days in a year. If I understand how it works, you would need a planet between Earth and Mars to have a year with a length between those two. StuRat (talk) 01:01, 8 March 2017 (UTC)[reply]

If you look at List of exoplanets and sort by orbital period, you will see that none are on that list. There is a lot of selection bias going on here, and planets with short orbital periods are much more likely to be identified. Graeme Bartlett (talk) 01:13, 8 March 2017 (UTC)[reply]

I was looking at the exact same table, while you typed that! So, "HD 95127 b" is 482 days, and "HD 564 b" is 494 days. For sure, there will be lots - billions upon billions! - which we're yet to discover.86.20.193.222 (talk) 02:14, 8 March 2017 (UTC)[reply]

The length of a year is not exactly 365.25 days. So, whatever mystical calculation you plan on doing will be wrong. We have a leap year every four years EXCEPT years ending in 00 unless the year is divisible by 400. 209.149.113.5 (talk) 14:35, 8 March 2017 (UTC)[reply]

For starters, my calculations (mystical, or otherwise) have never been wrong so far. :-) Secondly, I would be more interested in whether this value has ever been used historically in either astronomical or calendrical computations. — 79.113.199.220 (talk) 18:47, 8 March 2017 (UTC)[reply]

Yes. The length of a year has been used in many calculations along with many things, such as the number of books in the Old Testament or the number of planets in the Solar System or the number of toes on a four-toed hedgehog. Pick any day of any year and it is very likely that someone made a calculation that something would happen on that day. 209.149.113.5 (talk) 21:53, 8 March 2017 (UTC)[reply]

(Are you joking, or do you genuinely not know the difference between astronomy and astrology ?) — 79.113.199.220 (talk) 02:30, 9 March 2017 (UTC)[reply]

Also, tropical or sidereal? Or anomalistic? Sagittarian Milky Way (talk) 15:27, 8 March 2017 (UTC)[reply]

Both. If either you or someone else know of any planet out there whose `year span` (tropical, sidereal, anomalistic, etc.) lasts anywhere in between 485 and 490 days, please let me know. — 79.113.199.220 (talk) 18:47, 8 March 2017 (UTC)[reply]

Falling asleep in classrooms

In one of the lectures of a community college classroom, I dozed off and then rested during a brief video lecture. When the video ended, I just suddenly regained consciousness (or woke up). Why is that? --George Ho (talk) 02:46, 8 March 2017 (UTC)[reply]

Wikipedia's only major coverage seems to be Sleep#Awakening, but that has some references which may lead you to sources to answer your question. --Jayron 32 02:54, 8 March 2017 (UTC)[reply]

I was a champion lecture-sleeper in college, and it always seemed that sudden changes woke me up. If nothing else, everyone getting up at the end o the lecture would do it. I once dozed off during a lecture on sleep, and became an object lesson for the classroom. I don't have an answer for you specifically, but apparently the nature of arousal from sleep is a deeply complicated field [1]. Someguy1221 (talk) 03:55, 8 March 2017 (UTC)[reply]

OR: There can also be a very subtle trigger you become accustomed to. I regularly woke up at exactly 5:59 each morning, and my alarm was set for 6. I eventually figured out that the alarm made a little click when it hit 5:59, and that woke me up, not because it was itself loud enough to wake me, but because my brain took it as a warning to get up now as a jarring alarm would go off soon. StuRat (talk) 04:46, 8 March 2017 (UTC)[reply]

I quite often wake up just before my alarm goes off but not sure there is any clicking going on. One weird thing when I used to use a radio alarm is I used to dream about a particular song. Then I would wake up due to the alarm and that song would be playing. I remember hearing the alarm switching on waking me up and the song in my sleep definitely happened before the alarm went off. Explain that! Polyamorph (talk) 20:16, 8 March 2017 (UTC)[reply]

For the first one, assuming there is nothing else which happens before the alarm which you've learnt to associate with the waking up, the obvious issue is how consistent the time of your alarm is. If you always wake up at the same time, or at least the same time on the same day then you may very well have learnt to wake up at that time. If the times are not consistent at all, it's more complicated. First you need to really check (as StuRat mentioned) there is nothing else happening that you're associating with the alarm. I would generally expect a mobile phone won't for example, but you'd still need to check somehow. Then you'd need to check your are really waking up before most of the time and not just a few times and remembering those times, the timing of 'just before' is also relevant. Unless you've kept a careful diary (which is complicated anyway), there is a strong risk of confirmation bias. In fact, depending on the circumstances you may very well be waking up more than that and not remembering.

I admit I've sometimes felt I did the same, and with a mobile phone, and the times weren't consistent at all but I suspect it's probably a combination of confirmation bias and that I tend to wake up a lot anyway. I may also be taking clues from stuff like how dark it is etc. A good activity tracker which detects how many times you're waking etc would help here although you have to be very careful about timing and data quality etc, especially if you're trying to use it to determine if you really wake up before.

For the second one, two likely explainations are your memory of hearing the alarm switch on waking you up is faulty or you didn't actually have a song in your sleep before the alarm went off. People can often be a bit confused when waking up and can still be in a semi-dream state, so any memory of what happened and which one was first is always a bit circumspect.

Nil Einne (talk) 22:55, 8 March 2017 (UTC)[reply]

It is also common for the brain to subjectively move and expand dream memories in time. For instance, I have sometimes been awoken by external noises but had the memory to have seen the corresponding reason of that noise occur a while before the noise actually happened and woke me up (as if my brain had foreseen it). Similarly, we can have the impression to have had a long dream, while it may actually have been produced in a very short moment. I am not sure if this is related to the same phenomena, but hypnosis is notable as being able to produce false memories which are perceived by the subject to have occurred back in time, but were actually forged by suggestion during sessions (and hence hypnosis being considered a misleading investigation tool, other than aspects of it being considered pseudoscience)... PaleoNeonate (talk) 00:14, 9 March 2017 (UTC)[reply]

That's interesting! That a sleepy brain will mix up the order of short term memories which are perceived as real time experiences. Thanks for your answers.Polyamorph (talk) 09:28, 9 March 2017 (UTC)[reply]

I've often noticed that, when I flinch from a sudden noise, my memory of the flinch precedes my memory of the bang. From which I infer that between sensation and memory are multiple neural paths, differing in length. —Tamfang (talk) 06:27, 12 March 2017 (UTC)[reply]

More OR: I have found that when I'm dozing, like half-asleep, my hearing gets more acute, i.e. small noises which wouldn't normally grab my attention might wake me up. ←Baseball Bugs ^{What's up, Doc?} carrots→ 05:30, 8 March 2017 (UTC)[reply]

How tall was Homo erectus?

On the Homo erectus talk page there was a question about this paper:[2] The page doesn't appear to have any information at all about how tall and how heavy an adult homo erectus was. Does anyone have a source for that information? --Guy Macon (talk) 06:36, 8 March 2017 (UTC)[reply]

Apparently researchers in the field are reluctant to give height estimates. This paper suggests a height of between 1.64m and 1.68m for a particular H. erectus individual, and then immediately casts doubt on it. This source, which I can only see the preview of, states that one individual was estimated would have reached 1.85m in height had it survived (a reference I believe to Turkana Boy, whose potential height estimate was later lowered dramatically), and that no adult H. erectus skeleton has been recovered with an estimated height less than 1.58m. So in terms of prehistoric hominids, it sounds like they were actually quite tall, though they have also been described as quite skinny. There are uncertainties in the height measurements because no complete skeleton has ever been recovered of this species, and there are inherent uncertainties such as the distance between vertebra. Someguy1221 (talk) 07:30, 8 March 2017 (UTC)[reply]

I suspect that this is related to the fact that everyone has heard of T. Rex but nobody seems to have heard about Sarcosuchus imperator or Deinosuchus riograndensis. In the popular culture, big prehistoric reptilian predators all went extinct. Having one that has close relatives still alive today doesn't fit the narrative. Likewise, in the popular culture recent hominids were big, muscular brutes. Having one that was tall, skinny, walked upright and had a small brain doesn't fit the narrative. --Guy Macon (talk) 05:22, 9 March 2017 (UTC)[reply]

Wind noise

Two questions:

1) How exactly does wind translate into noise ?

2) I've noticed that below a certain speed, winds don't seem to make any noise at all. Is this due to laminar flow versus turbulent flow ? StuRat (talk) 16:22, 8 March 2017 (UTC)[reply]

This looks like some good recent research on the general topic, as it pertains to automobiles. This paper discusses the process as it pertains to sound engineers and microphones specifically, both seem to discuss wind noise in general, as well as how it pertains to specific fields of study. --Jayron 32 16:28, 8 March 2017 (UTC)[reply]

Also relevant to consider is that there are two, distinct, definitions of sound: the physics definition of a mechanical wave and the psychological definition of sound as qualia. When one asks "what causes wind noise", that implies both "how does wind cause vibrations in the air" and "how does the human mind perceive such noise". --Jayron 32 16:33, 8 March 2017 (UTC)[reply]

Thanks so far. Anyone else ? StuRat (talk) 18:13, 11 March 2017 (UTC)[reply]

Why are headlights green?

I'm not even sure "headlights" is the right term. I see these during the day. Newer cars in some cases have a row of white dots (almost blue, actually) which might be a half circle. Or they might be a full white circle in other cases. I started wearing a new pair of sunglasses and these lights are the only thing they change for white to a yellowish green.— Vchimpanzee • talk • contributions • 18:15, 8 March 2017 (UTC)[reply]

Daytime running lamps? Sagittarian Milky Way (talk) 18:22, 8 March 2017 (UTC)[reply]

Can you include a picture? It makes it easier for us to understand what you're talking about. --Jayron 32 18:23, 8 March 2017 (UTC)[reply]

This isn't exactly the same as what I've been seeing but it's close enough.— Vchimpanzee • talk • contributions • 19:36, 8 March 2017 (UTC)[reply]

These LED lights tend to be a bit bluer (to me, at least) than 'normal' headlights. Colour perception is notoriously difference between people, maybe you're perceiving them as greener. Fgf10 (talk) 19:49, 8 March 2017 (UTC)[reply]

They do look blue to me. But not with these sunglasses on. Older sunglasses that broke didn't do this.— Vchimpanzee • talk • contributions • 20:45, 8 March 2017 (UTC)[reply]

Lots of sunglasses are designed to block blue light (the hardest color to focus, I think?). So from your description, it seems likely that the (bio-adjusted) intensity profile of the lights has some red, a medium amount of green, and peaks in the blue. Your sunglasses filter out the blue, leaving the green. I don't have enough information to give a more precise answer, and in any case color vision is very complex so any treatment like this is bound to be oversimplified, but my speculation is that this is what is going on. --Trovatore (talk) 20:52, 8 March 2017 (UTC)[reply]

Although it is possible to make a white LED, most such LEDs are actually clusters of LEDs emitting three colors that combine to appear white. If you block one completely, the effect would be quite noticeable. Someguy1221 (talk) 01:33, 9 March 2017 (UTC)[reply]

I don't know who mentioned blocking anything "completely". Many sunglasses are designed to block blue light, but of course not completely. --Trovatore (talk) 02:04, 9 March 2017 (UTC)[reply]

I mentioned it, to make a point, which I guess didn't come through. I have a suspicion that applying a narrow absorption spectrum to a "peaky" emission of light (google "white LED emission spectrum" to see how bimodal these are) will have a more dramatic effect than applying the same peak to a blackbody spectrum that appears to have the same color. Someguy1221 (talk) 03:28, 9 March 2017 (UTC)[reply]

Indeed. I'd note there's no particular reason you can block one LED unless it has some special polarisation or something. What you will block are wave lengths and it doesn't matter how they are produced. Certain methods will produce more peaky spectra but it's too complicated to say just RGB will do that. Nil Einne (talk) 02:40, 9 March 2017 (UTC)[reply]

I thought it would have been obvious I was referring to a sunglass coating whose emission/reflection spectrum is centered on one wavelength that happens to be close to one of the peaks in the LED's emissions. Someguy1221 (talk) 03:30, 9 March 2017 (UTC)[reply]

The problem is this is still IMO conflating two different things.

TLDR version is if phosphor coated LEDs had not come to predominate because of luminous efficacy advantages, I'm not convinced typical white LEDs which were multichip would necessarily be more peaky than they are now. (The SPD may be different sure.) Whether this would be from more than 3 LED colours or some other strategy I can't say but it seems to me some strategy would have been used. In other words, the issue of white LEDs generally being RGB other than being untrue is IMO mostly a red herring even if the peakiness of the SPD is relevant. Multichip LED don't have to be and probably wouldn't be so peaky if they were the norm and phosphor coated LEDs are still a bit peaky and would potentially be more so if no one cared about them.

Looking online, it does seem most RGB LEDs still have a fairly peaky SPD. One of the best I found was this using a collimator [3] but even that is still tripeaked. Much more common is something like this [4].

But low CRI phosphor white LEDs can also be peaky particularly in the blue part of the spectrum (which seems particularly relevant to this question), see [5] and [6] or the earlier sources. More to the point, I don't see any reason why a RGB LED intrinsicly has to be tripeaked. Making a fairly broad SPD R, G and B LED is probably difficult and may require a phosphor coating or similar, probably one reason development hasn't been particularly successfully. And I see even less reason why a phosphor coated LED couldn't be tri-peaked (and I also question if tri-peaked matters so much here since we're probably only talking about cutting of one peak). Possibly the development of phosphor coated LEDs was helped by earlier research for other purposes e.g. fluorescent lights but I'm not sure (I may have known at one time, but can't remember).

Regardless even if it is easier, I think there's a fair chance a key reason why decently broad SPD and decent CRI phosphor white LEDs are so much better than RGB LEDs is since that's where the research is due to the luminous efficacy advantage. IIRC green LED luminous efficacy is the biggest problem and until this is solved, RGB LEDs are only going to have niche applications.

And some of these applications are reducing since the research into phosphor white LEDs means some degree of spectrum tunability is now achieved using multichip LEDs with a white LED as I mentioned (see e.g. [7]). Besides that I also came across some sources mentioning using more than 3 colours [8] [9] (one seems commercial, one research), I'm not sure whether these are at all common but ultimately most manufacturers are going to concentrate on what works and is cost effective etc, not in proving they can create a broad SPD RGB LED.

While broad SPD may be related, it isn't necessarily the target anyway. CRI is generally more important although the usefulness of CRI to LED colour rendering performance is often questioned for LEDs anyway [10] [11] [12] [13] [14]. Not that this means such a peaky SPD is considered good, in fact IIRC (and also what I think I saw from a quick skim through the sources) one of the concerns is that peaky spectrum can achieve a decent CRI but even there a different peaky spectrum may often be better yet achieve a lower CRI. But this also doesn't mean the typical idea is just need a broad SPD with no peaks in the visible spectrum. And this is complicated by other targets like luminous efficacy, CCT etc too. E.g. I didn't look that well into this research [15], but it sounds like they're suggesting using low CRI lighting in unimportant places. (Although 2007 is very old in LED research.)

Typical white LEDs is perhaps not the best reference point anyway. There is a fair amount of research into how different SPD, CCT etc affect headlamp performance. This is mostly in how it affects illumination and visibility of stuff that matters to drivers at night but I'm sure there must be some into how it affects performance of daytime running lights. Which isn't to say there isn't also a lot of marketting etc. [16] [17].

Nil Einne (talk) 13:57, 9 March 2017 (UTC)[reply]

That isn't true. Most white LEDs are blue LEDs with a phosphor coating. RGB LEDs are only used for niche cases. If you don't believe me look at a white LED or do a search. Many LEDs do use clusters but that's a different point. Note that clusters of different colours are sometimes used for improved colour rendering or adjustment but these aren't necessarily be RGB. They may in fact have one or more white LEDs. Nil Einne (talk)`

News to me! And you're right! From sleuthing on Google Scholar, it looks like single-color LED with a phosphor coating exceeded three-color LEDs in efficiency sometime in the mid-late 90s. Someguy1221 (talk) 03:28, 9 March 2017 (UTC)[reply]

No problem and sorry for the tone. I was tired and also editing from a mobile device. Nil Einne (talk) 10:21, 9 March 2017 (UTC)[reply]

Ah, no offense taken. My fault for relying on an electronics textbook written in '93. Someguy1221 (talk) 23:01, 9 March 2017 (UTC)[reply]

I wore different sunglasses today and the lights are back to white. I bought the sunglasses yesterday since the new ones that turn the lights green were the last pair I had left that weren't broken in some way. And they specifically said they block ultraviolet light. I don't know what I did with the tag on the others.— Vchimpanzee • talk • contributions • 17:00, 10 March 2017 (UTC)[reply]

Could they have been high-intensity discharge lamps ? "Beginning in the early 1990s, HID lamps have seen applications in automotive headlamps. Xenon, or high-intensity discharge (HID), lighting provides brighter headlights and increases visibility of many peripheral objects (e.g. street signs and pedestrians) left in the shadows by standard halogen lighting." These tend to look blue, versus the more yellow look of traditional headlights: [18]. StuRat (talk) 21:54, 10 March 2017 (UTC)[reply]

I think we established what I was seeing with the new sunglasses weren't those. And this week I quit wearing the sunglasses that turned those lights green, saving them in case something happens to the newer ones.— Vchimpanzee • talk • contributions • 18:13, 11 March 2017 (UTC)[reply]

March 9

How did Mammuthus spp. die out but Homo sapiens survive?

During the last Ice Age, how did Homo sapiens survive? Shouldn't Homo sapiens be extinct too because of climate change that killed the food supply? 166.216.159.20 (talk) 03:20, 9 March 2017 (UTC)[reply]

Your question is based on a false premise - the scientific community has not agreed on a cause for the extinction of mammoths, see Mammoth#Extinction. Climate change is suspected to be a major component, but not the sole cause. Even if we did assume food supply as a cause, the human diet is much broader than the Mammoth diet, as you're comparing an omnivore to an herbivore. Someguy1221 (talk) 03:33, 9 March 2017 (UTC)[reply]

Wikipedia has an article on said extinctions of megafauna. See Quaternary extinction event. As noted by Someguy, you'll not find a "here's what we know caused it" type answer, but rather "here's a half-dozen possible things that caused it, and some or all of these may have contributed to some degree". --Jayron 32 03:40, 9 March 2017 (UTC)[reply]

The distinction between omnivores and herbivores raises another issue that would've contributed to mammoth extinction while helping humans survive. Ian.thomson (talk) 03:47, 9 March 2017 (UTC)[reply]

Indeed. In simple terms, humans could eat mammoths but mammoths couldn't eat humans. Gandalf61 (talk) 09:03, 9 March 2017 (UTC)[reply]

Isn't it true in more than one way -- i.e. that overhunting by cavemen contributed to the mammoths' extinction? 2601:646:8E01:7E0B:9031:2E93:E491:EE2 (talk) 10:58, 9 March 2017 (UTC)[reply]

Do any of you have some reading on any of this, or are we just making it up as we go along? --Jayron 32 11:24, 9 March 2017 (UTC)[reply]

"Mammoths were herbivores so were very dependent on gaining all the nutrients they needed to survive from the plants that they ate... a poor habitat as a result of climate change, combined with increased contact and hunting by humans as they increasingly entered their areas of habitat led to their eventual extinction" Why Did The Wooly Mammoth Die Out, National Geographic. Gandalf61 (talk) 21:49, 9 March 2017 (UTC)[reply]

Additionally to what others have said, the extinction of one species, even in the course of a mass extinction event, does not mean that all other species must go extinct. If it did, life itself would not have survived the Cretaceous–Paleogene extinction event that killed the non-avian dinosaurs, or the many other extinction events over time. Life, of course, has survived mass extinction events. Some species survive, others fail, for reasons of natural selection and fitness to their changing environment or flexibility to adapt to it. --OuroborosCobra (talk) 15:58, 9 March 2017 (UTC)[reply]

Moreover, humans have an obvious adaptibility advantage, other than being able to vary the diet and to more efficiently disperse heat. Intelligence, allowing to pass knowledge from generation to the next through culture, map and mark territory, invent and build tools and traps, create or adapt shelters, create and wear clothing, use fire, carry water, manage resources, establish concurrent social roles (infant protection and raising vs education vs hunting and fighting) etc. PaleoNeonate (talk) 18:20, 9 March 2017 (UTC)[reply]

I forgot to mention it, but an important factor for survival is also the metabolic rate; despite our energy-hungry brain, humans do not have to actively feed all-day to meet its nutritional requirements. PaleoNeonate (talk) 18:27, 9 March 2017 (UTC)[reply]

I'd like to speak to the premise of the question (I don't think there's an agreed upon answer for the actual question beyond the fact that humans were clearly more in charge of their environment than other animals at that point - fire is a great ally). Mammoths and mastodons (and others) went extinct and a handful of elephant species survived to modern times. Erectus and Neanderthalensis (and others) went extinct and Homo sapiens survived to modern times. Both families seem to have enduring the same kind of 'pruning', but you're comparing apples and oranges, so to speak, and wondering why they're different. Mammoths and humans occupied very different ecological niches and habitats so comparing them is always going to be problematic. A better question is to compare within a niche or clade or geographical area and examine differential survival rates. Incidentally, humans and elephants are by no means unique in this regard. Old school attempts to force evolutionary history into a straight line obscures that - and leads people to make the same kind of error the OP did. Rather unfortunately, our lead pic in evolution of the horse makes the same mistake, though the caption at least attempts to address the issue. Matt Deres (talk) 19:37, 9 March 2017 (UTC)[reply]

See here: "Woolly mammoths (Mammuthus primigenius) populated Siberia, Beringia, and North America during the Pleistocene and early Holocene. Recent breakthroughs in ancient DNA sequencing have allowed for complete genome sequencing for two specimens of woolly mammoths (Palkopoulou et al. 2015). One mammoth specimen is from a mainland population 45,000 years ago when mammoths were plentiful. The second, a 4300 yr old specimen, is derived from an isolated population on Wrangel island where mammoths subsisted with small effective population size more than 43-fold lower than previous populations. These extreme differences in effective population size offer a rare opportunity to test nearly neutral models of genome architecture evolution within a single species. Using these previously published mammoth sequences, we identify deletions, retrogenes, and non-functionalizing point mutations. In the Wrangel island mammoth, we identify a greater number of deletions, a larger proportion of deletions affecting gene sequences, a greater number of candidate retrogenes, and an increased number of premature stop codons. This accumulation of detrimental mutations is consistent with genomic meltdown in response to low effective population sizes in the dwindling mammoth population on Wrangel island. In addition, we observe high rates of loss of olfactory receptors and urinary proteins, either because these loci are non-essential or because they were favored by divergent selective pressures in island environments. Finally, at the locus of FOXQ1 we observe two independent loss-of-function mutations, which would confer a satin coat phenotype in this island woolly mammoth." Count Iblis (talk) 20:11, 9 March 2017 (UTC)[reply]

Mammoths aren't extinct. They are just waiting for us to clone them back into existence. :-) StuRat (talk) 21:49, 10 March 2017 (UTC) [reply]

Feeding boogers to tropical fish

I must ask, is it okay for children to regularly feed boogers to a tank of tropical fish? Anna Frodesiak (talk) 12:51, 9 March 2017 (UTC)[reply]

Cattle population historical chart

Does anyone know where I can find a chart of the cattle population in the world since domestication, showing how it has increased (and possibly sometimes, reduced) from century to century? --Lgriot (talk) 13:56, 9 March 2017 (UTC)[reply]

I don't think the Romans kept track of their cattle. A few latest years are here.[20] --AboutFace 22 (talk) 21:40, 9 March 2017 (UTC)[reply]

Any approximation would be fine, I don't need the numbers from a statistical government department, just any historian's / archeologue's / biologist's estimate would do. --Lgriot (talk) 16:18, 10 March 2017 (UTC)[reply]

Might be possible to estimate through atmospheric methane, if the other major sources could be corrected. Probably not possible post-industrial revolution by this method. Klbrain (talk) 00:53, 12 March 2017 (UTC)[reply]

That is an interesting idea, although it will also include other natural sources of methane production than cattle (Methanogenesis#Natural_occurrence) and even possibly methane of non-organic origin when going far back enough (abiotic methane, Abiogenic_petroleum_origin#Example_proposed_abiogenic_methane_deposits). PaleoNeonate (talk) 05:05, 12 March 2017 (UTC)[reply]

Press and hold to turn on electronic device

A friend is building some type of battery-powered electronic device and has asked me general questions about breadboarding. Having got the device to work, he would like to add a pushbutton which would require a long press (say 2 seconds) to turn on the device. I've see smart phones and meters with such a feature: presumably there is a very low-current-draw circuit which monitors the on switch, the powers up the main device(perhaps with a small microcomputer in it) which has a much higher current draw. This would prevent accidental turn-on and provide longer battery life than if the device were always at high current draw but muted. Any suggestions as to where to find coverage of this? Edison (talk) 19:50, 9 March 2017 (UTC)[reply]

Without a CPU the way I think your friend can do it is simply with a circuit where by a capacitor can be charged until it switches on a transistor which activates the device. The time delay being the value of the resistor between the power rail (connected by depressing the switch) and the capacitor value. Not being able to see the circuit diagram can't advise any better. Yes, it is doable very simply.--Aspro (talk) 20:14, 9 March 2017 (UTC)[reply]

You can email me the circuit diagram if you like (as I only charge $90 an hour consultancy fees). Yet, from this your friend can grasp the basic principle and adapt it.--Aspro (talk) 20:25, 9 March 2017 (UTC)[reply]

Search for "delay timer circuit" - for example this one. Gandalf61 (talk) 21:37, 9 March 2017 (UTC)[reply]

Yep. That ticks the box. Note: it shows an electrolytic capacitor and so did my example. This is a must.--Aspro (talk) 23:14, 9 March 2017 (UTC)[reply]

Are humans really grass eaters?

By grass, I mean members of the Poaceae family - rice, wheat, maize, and rye. Those are also staple food, which means they compose the majority of the diet because of high energy density. Does that mean that humans in temperate climates are primarily herbivorous omnivores, eating mostly various types of grass as a staple food? 66.213.29.17 (talk) 20:35, 9 March 2017 (UTC)[reply]

Most of us don't eat grass, we eat the grain or its products. ←Baseball Bugs ^{What's up, Doc?} carrots→ 21:13, 9 March 2017 (UTC)[reply]

See staple food. A staple food is that from which a population gets the most of its food energy (calories). And the biggest staples are either grains or root vegetables, depending on the climate. Of the top ten staples, #1, 2, 3, and 9 are grains, #4, 7, and 8 are roots, 6 is a legume, and 10 is a fruit. Cereal grains are all botanically grasses. --Jayron 32 21:25, 9 March 2017 (UTC)[reply]

There is a trick in the nomenclature here. When you use the term 'grass eater', it strongly implies the eating of the plant itself (i.e. graminivore) rather than just a particular part (i.e. granivore). Humans by and large do not 'eat grass' in that sense; we would get very little nutrient from the indigestible fibre the grass leaves are composed of. It would be like asking 'Are humans really tree eaters?' because apples are popular. Grass eating men is something very very different. Matt Deres (talk) 22:33, 9 March 2017 (UTC)[reply]

Indeed, and our teeth are not adapted for large scale or long term grass eating (compare to File:Crâne_cheval.jpg for instance). PaleoNeonate (talk) 23:20, 9 March 2017 (UTC)[reply]

Sugar is usually made from grass: sugar cane in many places or corn in USA. Graeme Bartlett (talk) 12:29, 10 March 2017 (UTC)[reply]

... or Sugar beet. Dbfirs 14:25, 10 March 2017 (UTC)[reply]

That is not a grass though! It accounts for 20% of world production. So grass has 80% share. Graeme Bartlett (talk) 05:56, 11 March 2017 (UTC)[reply]

Quorn question

According to this per 100g it has 2g of fat, 0.5g of saturates, 4.5g of carbs, 0.6g of sugar, 5.5g of fibre, 0.3g of salt, and 14.5g of protein. That's only 27.9g. What is the remaining 72.1g made of? — Preceding unsigned comment added by 177.2.64.216 (talk) 20:38, 9 March 2017 (UTC)[reply]

Water.--Aspro (talk) 21:05, 9 March 2017 (UTC)[reply]

Yes -- in case a ref is needed, this site shows water content of various mushrooms, which are in the same ballpark. Henry ^Flower 21:08, 9 March 2017 (UTC)[reply]

Rather eat any of those various mushrooms than quorn, which I find horrid -even if it is cheap. --Aspro (talk) 21:37, 9 March 2017 (UTC)[reply]

For those who, like me, had no idea what Quorn was, here's a convenience link. --Trovatore (talk) 09:08, 10 March 2017 (UTC)[reply]

Thank you. Judging by the header (before I read the question), I figured it was an SA question, since I've only ever encountered "Quorn" in the Rain follows the plow article. Nyttend (talk) 05:32, 11 March 2017 (UTC)[reply]

Trickshots

Due to some impossible physics (particularly at 2:06, 2:11, 2:15 and 2:38) are those some kind of remotely guided balls? Sifting thru comments, trickshot and google was not particularly helpful. Brandmeister^talk 21:38, 9 March 2017 (UTC)[reply]

Those are most likely real and for certain possible.--TMCk (talk) 21:50, 9 March 2017 (UTC)[reply]

I see nothing to indicate those are impossible physics. See Glossary of cue sports terms#english. Enough practice and those shots can be made by anyone. --Jayron 32 21:53, 9 March 2017 (UTC)[reply]

Glossary of cue sports terms#draw is also relevant. PrimeHunter (talk) 00:05, 10 March 2017 (UTC)[reply]

Yes, they all look natural, (if very, very difficult) to me. (I watch a lot of snooker, though with my eyesight I can no longer play.) You may notice that the demonstrator is using a white ball with spots, so that you can see the imparted spin which causes the arcing trajectories, reversals etc. Bear in mind that for each shot you're only seeing the take where it worked, not the possibly dozens of takes where it didn't. {The poster formerly known as 87.81.230.195} 90.202.209.145 (talk) 22:38, 9 March 2017 (UTC)[reply]

March 10

Flat Earth Hypothesis is easily proven wrong

How do flat earth people explain the fact that the moon appears upside down when viewed in Australia as compared to viewing in Canada (at the same time)? I like to hear the flat earth scientific explaination. 148.182.26.69 (talk) 02:18, 10 March 2017 (UTC)[reply]

Who says it looks upside-down in Australia? ←Baseball Bugs ^{What's up, Doc?} carrots→ 03:21, 10 March 2017 (UTC)[reply]

People from the northern hemisphere who go to Australia and look. Matt Deres (talk) 03:30, 10 March 2017 (UTC)[reply]

I see what they're getting at. It's all in the way you're looking up at it. And it seems that there is a lot of stuff in Google about how this "proves" the earth is round. I'm not so sure that's definitive. ←Baseball Bugs ^{What's up, Doc?} carrots→ 03:37, 10 March 2017 (UTC)[reply]

Flat Earthers believe there is an international conspiracy comprised of every national government, every airline employee, major shipping companies, anyone involved in space travel, and the entire population of the southern hemisphere. I would not expect any sort of evidence to sway them. As Jonathan Swift said, "Reasoning will never make a Man correct an ill Opinion, which by Reasoning he never acquired." Someguy1221 (talk) 03:59, 10 March 2017 (UTC)[reply]

Ole was driving home and Lena called him on his cell. "Be careful, Ole, dere's some idiot drivin' de wrong way on de expressway!" Ole said, "Dere's not yust one, dere's hundreds of 'em!" ←Baseball Bugs ^{What's up, Doc?} carrots→ 04:33, 10 March 2017 (UTC)[reply]

Not just the moon, even the constellation of Orion is upside down. "In ancient Greek mythology, Orion was a legendary hunter. To us in the southern hemisphere, he appears upside-down and is quite easy to recognise." from the website 148.182.26.69 (talk) 05:13, 10 March 2017 (UTC)[reply]

They're not upside-down if you're facing south while looking up at them. ←Baseball Bugs ^{What's up, Doc?} carrots→ 05:45, 10 March 2017 (UTC)[reply]

Generally speaking, you can't see a northern constellation at all while facing south and standing in the southern hemisphere. A bit more complicated than that, but it's the gist. Someguy1221 (talk) 06:12, 10 March 2017 (UTC)[reply]

Maybe a question for Wikipedia:Reference Desk/Pseudoscience? Tigraan^{Click here to contact me} 09:00, 10 March 2017 (UTC)[reply]

Assuming you're standing straight up and down. But here's the thing: if you were to lie/recline back on something so you can see objects in the northern sky, then their orientation is the same as in the Northern Hemisphere. The only reason for the perceived difference is that the guys in the Northern Hemisphere normally, under gravity, are tilted north, while the blokes in Australia looking in the same direction in the sky are typically tilted south. Up is not up. Wnt (talk) 12:17, 10 March 2017 (UTC)[reply]

As said by others, this doesn't seem to be a science question but see [21] [22] [23] [24]. There's even videos if you prefer [25] [26] [27] [28]. Nil Einne (talk) 10:21, 10 March 2017 (UTC)[reply]

That the moon appears the other way up in Australia does not disprove that the earth is flat. It is just a matter of perspective. If the moon is 45 degrees above the southern horizon in the north and 45 degrees above the northern horizon in Australia then it must be about 3000 miles above the earth and have a diameter of about 25 miles. This has been obvious to people for centuries, it is sad that people nowadays can't work these things out for themselves rather than believing everything the military-industrial complex wanting billions for their rockets pushes at them ;-) Dmcq (talk) 11:46, 10 March 2017 (UTC)[reply]

Any fool can look out his window and see that the earth is flat.[29][30] --Guy Macon (talk) 15:55, 10 March 2017 (UTC)[reply]

So if i am just slightly north of the equator watching the moon, and i step south, across the equator, when does the moon flip? Greglocock (talk) 17:28, 10 March 2017 (UTC)[reply]

Till at least 2025 AD the Moon can be upside down as far north as 20+ km north of central Orlando, parts of Texas and halfway between Shanghai and Taiwan Island. But only for a small fraction of the year once every 18 or 19 years. In reality it might not look that upside down without a plumbbob till hundreds of kilometers further south. When the Moon's overhead as far south as it gets it could appear north side up in the northernmost Australian state capital (Brisbane) but maybe so close to overhead that you couldn't tell. Sagittarian Milky Way (talk) 04:23, 11 March 2017 (UTC)[reply]

When you turn your body 180 degrees. ←Baseball Bugs ^{What's up, Doc?} carrots→ 19:36, 10 March 2017 (UTC)[reply]

If you're that near the Equator, you'll be looking directly overhead to see the Moon. So one can't really define which way is "up" when looking at the Moon, unless also stating which direction you're pointing in. Andy Dingley (talk) 20:29, 10 March 2017 (UTC)[reply]

?Directly overhead? how come. Its on the horizon quite oftenGreglocock (talk)

The equator also makes the Moon lie on its side much more than at middle latitudes. Sagittarian Milky Way (talk) 04:23, 11 March 2017 (UTC)[reply]

The Moon being north of you relative to the ground in one place and south of you relative to the ground in another is not inherently contradictory with at least some flat-earth theories (i.e. there might be some that suppose some kind of exotic geometry where all bets are off. That seems to be pretty common among the more "educated" or "internet-savvy post-ironic" flat earthers); indeed, if the earth is a plane section and the moon is above it then surely there exists a line segment on the plane section for every angle T such that T is the angle in the planar dimension between every point on that segment and the moon. That is, if you're standing in a ballroom and look up at the chandelier in the center, then walk across the ballroom and look at it again, you'll both have to look in a different direction AND see a different part of the chandelier. 97.93.100.232 (talk) 02:59, 11 March 2017 (UTC)[reply]

Actually that is the basis of a contradiction, because you don't see many different parts of the Moon in the North and South - the difference is only what you'd expect for a ball a quarter of a million miles away, whereas (as Dmcq calculated) if you assume the Earth is a plane and the Moon above it, the Moon is only 3000 miles away, which means that observers in different hemispheres should see almost half of a landscape unique from their position. Of course, belief in a Flat Earth lends itself to belief in a Flat Moon that only happens to look like a ball in the sky, in which case you both see exactly the same terrain ... which is again disprovable, but only with some fancy telescopes doubtless owned by compliant geeks who suck up to the Elders of Zion. But there's also the question of why the flat Moon doesn't look like an ellipse from far north and far south, which I'd think could be addressed with some really remarkable handwaving about atmospheric phenomena that distort the view of it (but not the stars behind it). The Flat Earth thing doesn't really hold water; we just have to be careful about using disproofs that only work if you assume the Earth isn't flat. Wnt (talk) 20:22, 11 March 2017 (UTC)[reply]

How could time zones exist in-universe? Do Flat Earthers never call an overseas person they trust at sunset and ask whether it's setting now? Sagittarian Milky Way (talk) 21:21, 11 March 2017 (UTC)[reply]

At what height are hill/mountains made from rock?

Mountains in Colorado for example look like they are made from rock but other mountains in other places look like they are made from dirt but are actually made from rock underneath. How do you know if a mountain or large hill is all dirt or has rock underneath? Does it happen at a certain height?--Sara203040 (talk) 03:02, 10 March 2017 (UTC)[reply]

It's all rock if you go deep enough. Lower elevations are warm enough for vegetation to grow, which over time Soil accumualtes. Above the Tree line, it's mostly just rock and ice. ←Baseball Bugs ^{What's up, Doc?} carrots→ 03:39, 10 March 2017 (UTC)[reply]

Actually, beneath that it's turtles all the way down. μηδείς (talk) 03:58, 10 March 2017 (UTC)[reply]

For further information, see Turtle Rock. ←Baseball Bugs ^{What's up, Doc?} carrots→ 04:35, 10 March 2017 (UTC)[reply]

Wikipedia has not one, but at least two articles on mountain building, Mountain formation and Orogeny. It's a complex process, but Wikipedia's articles are a good a place as any to start learning. --Jayron 32 03:45, 10 March 2017 (UTC)[reply]

Some hills are made of sediment (sand, mud, gravel, probably some loose rocks) rather than solid rock. However, these are particular types of hills, defined by how they were formed rather than just their size. Iapetus (talk) 11:03, 10 March 2017 (UTC)[reply]

The depth of the rock bed under topsoil can be mapped using techniques of Reflection seismology if a controlled Seismic source such as a vibrator or explosives is available, or by Ground-penetrating radar which can penetrate up to 15 meters in some soils (or much deeper through ice) at low radio frequencies. A natural indicator of non-porous bedrock is at the level of the Water table where water springs emerge. Blooteuth (talk) 13:48, 10 March 2017 (UTC)[reply]

If you are interested in dirt formation in mountains, there are many studies done at the Biltmore estate. It was a barren mass of red clay hills before work was done to get a forest growing again. It now has soil on top of the clay throughout most of the forest. Understanding how the soil was replenished by regrowing the forest helps explain how mountains have dirt below the tree level, but not above it. 209.149.113.5 (talk) 18:13, 10 March 2017 (UTC)[reply]

Sour strawberries

I know sucrose is sweet, and dissociation of an acid is sour. But why are most of my store bought strawberries sour? 166.216.159.224 (talk) 15:52, 10 March 2017 (UTC)[reply]

The Strawberry article doesn't overtly say, but it's possible they're picked before they're fully ripe. ←Baseball Bugs ^{What's up, Doc?} carrots→ 16:15, 10 March 2017 (UTC)[reply]

This may be helpful. It should be noted that, depending on where you are located, strawberries are not likely in season. Your IP address geolocates to Michigan; your local season is late may-early june. That means your berries from your store may be shipped in from somewhere else, quite possibly as far away as the other side of the planet (a lot of fruits in the Winter in the U.S. are grown in Chile and shipped to the U.S.) and as such, they are usually picked "underripe" so they don't spoil on the trip. ~~The under-ripe strawberries are treated with ethylene to "redden" the surface, but that doesn't effect the flavor.~~ here is some good information on off-season strawberries. --Jayron 32 16:33, 10 March 2017 (UTC)[reply]

Do you have a source for the ethylene ripening not changing flavor? Maybe it's different in different fruits. For example Bananas are treated similarly, shipped green then ripened with ethylene. Our ripening article also has some nice info at the top on acidity, sourness and sweetness of fruit. To me, (WP:OR) ripened bananas taste different than green bananas, and I have ripened green bananas at home using the ethylene from ripe bananas - these also change in sweetness and flavor. SemanticMantis (talk) 16:41, 10 March 2017 (UTC)[reply]

So amended per [31] Underripe strawberries do not respond to ethylene. Thanks for the correction. Strawberries do not ripen after picking, and looking deeper into sources I cited above, specific breeds of strawberries are grown for long-distance shipping. These breeds are naturally lower in sugar, so taste less sweet and more sour. The lower sugar content results in longer shelf life, but makes them less sweet than breeds grown for local market use. --Jayron 32 16:48, 10 March 2017 (UTC)[reply]

Ethylenecontrol.com has some detailed info on lots of relevant stuff, thanks! SemanticMantis (talk) 21:27, 10 March 2017 (UTC)[reply]

Also note that strawberries, even when fully ripe, aren't all that sweet. [32] (switch to 100 g serving), lists only 5 grams of sugar per 100 gram serving. Compare that to honey: [33], which has 82 grams of sugar per 100 grams, or a mango, which has 15 grams of sugar per 100 g serving: [34]. Many people add some form of sugar, such as sugar added to whipped cream, to their strawberries. StuRat (talk) 21:34, 10 March 2017 (UTC)[reply]

Good point. I like them just the way they are, personally, but most (that I've seen anyway) do seem to sweeten them before eating. Earl of Arundel (talk) 22:32, 10 March 2017 (UTC)[reply]

March 11

Why does salt make food taste better?

I boiled baby spinach leaves in water in a big pot. In a skillet, I cooked tofu cubes on the skillet and turned so that both sides appeared brown, indicating that it'd be crispy. The spinach diffused green color to the liquid. I transferred some spinach broth and spinach to a bowl and added the tofu cubes. It tasted bland. But adding salt made the food more palatable. Why? 107.77.194.158 (talk) 01:31, 11 March 2017 (UTC)[reply]

You develop a preference for foods with salt concentrations similar to what you are used to. You can even train this by forcing yourself to eat food with salt concentrations outside your normal comfort zone (either high or low) for several weeks. So if you start adding only half the normal amount of salt to your soup for a few weeks, thereafter the original amount of salt may start to taste excessive. Your salt preferences can also change based on how much salt you've eaten that day. Here are just a few studies on these effects: [35][36][37]. Going on Google Scholar and searching for something like "salt taste preference" will turn up a nearly unlimited number of studies of this phenomenon. It's even true for other mammals, such as mice. Someguy1221 (talk) 01:39, 11 March 2017 (UTC)[reply]

Within a certain range, yes, but sodium is an important nutrient, so we all will crave it, to some extent. Unfortunately, this nutrient rarely occurs in quantity in natural foods (other than seafood) but is now common in prepared food, so our cravings, which were appropriate when it was rare, are now unhealthy, when it is common. Note that we have salt-detecting cells on our tongues: [38]. Also note that "too salty" is highly unpalatable, although that threshold will vary by individual. StuRat (talk) 01:42, 11 March 2017 (UTC)[reply]

If you are trying to reduce sodium intake, one way to deal with bland foods is to add other spices, such as peppers. The capsaicin can fix the bland problem. However, be careful when using something like hot sauce, as those are often high in sodium, too. StuRat (talk) 01:55, 11 March 2017 (UTC)[reply]

In my case, I started enjoying hot sauce with my food when I discovered Sriracha sauce (Huy Fong Foods), which in my opinion makes other popular hot sauces taste vile and malodorous by comparison. I noticed the fairly high sodium content, but I also noticed that if I used enough to where sodium is an issue my mouth would be a volcano. A little goes a long way. --Guy Macon (talk) 02:56, 11 March 2017 (UTC)[reply]

Too sweet for my taste, and too much — something. Vinegar? Garlic? Not sure. Anyway I prefer or Tapatío or Cholula. But de gustibus and all that. --Trovatore (talk) 03:26, 11 March 2017 (UTC) [reply]

Using my 2nd link below, those have 110mg and 85mg, respectively, per 5 g serving. StuRat (talk) 18:10, 11 March 2017 (UTC) [reply]

Yea, looks like 60mg per 5g serving: [39]. That's not bad, as long as you keep to that serving size, although this source puts it at 100mg per 5 g serving: [40] and lists others with ranges from 26mg to 220mg, so it's worth shopping around. StuRat (talk) 03:07, 11 March 2017 (UTC)[reply]

Recreational drug use in animals

In what ways do animals use drugs recreationally, and which drugs?

Perhaps I should qualify: I mean wild animals consuming substances e.g. plants, at least in part, because of the effect of the drug. I believe that animals consume opium poppy latex, but I am not aware of any other recreational drug use in animals.--Leon (talk) 09:10, 11 March 2017 (UTC)[reply]

It's sometimes claimed Catnip#Effect on cats for various cat species although I'm not sure whether this happens in the wild much. The range for catnip and various Leopard and probably Lynx and catnip would seem to overlap so it's possible. Nil Einne (talk) 09:35, 11 March 2017 (UTC)[reply]

I don't know the quality of this source [41] but you could probably search the examples and it also mentions 2 books that would seem to be of interest. P.S. The examples in the above source also seem to be sourced themselves with RS. Although some of them are newspapers the bigger issue is probably the website's interpretation anyway. Nil Einne (talk) 09:40, 11 March 2017 (UTC)[reply]

Apparently dolphins have taken to chewing puffer fish, as was reported just lately. Andy Dingley (talk) 10:13, 11 March 2017 (UTC)[reply]

Reindeer are known to like fly agaric. Cheers ✦ _hugarheimur 11:20, 11 March 2017 (UTC)[reply]

Birds are known to get drunk on fermented berries. Jahoe (talk) 12:41, 11 March 2017 (UTC)[reply]

Pigs like to eat fermenting apples, apparently. --TammyMoet (talk) 14:47, 11 March 2017 (UTC)[reply]

The widely held belief that elephants get drunk on fermented fruit has been shown to be a myth. ^[1] Roger (Dodger67) (talk) 18:35, 11 March 2017 (UTC)[reply]

^ http://news.nationalgeographic.com/news/2005/12/1219_051219_drunk_elephant_2.html

Sigh.

Ref regarding dolphins chewing puffer fish.

Ref for reindeer eating mushrooms and also discusses several other animals that consume psychoactive substances.

Ref regarding birds getting drunk off of berries.

Another generic ref on the subject, with a link to a more scholarly disputation on the drunk elephant story. Matt Deres (talk) 19:29, 11 March 2017 (UTC)[reply]

FWIW, the source I linked above before all of the replies (I did add the P.S. after some of them) includes this video of dolphins [42]. It also suggests the mushroom thing applies to moose as well as caribou/reindeer but I'm unclear whether the book it uses Animals and Psychedelics: The Natural World and the Instinct to Alter Consciousness ISBN 978-0892819867 mentions moose since it's not discussed in the abstract/reviews. It also mentions several more animals for alcohol including bees, fruit flies and monkeys although I'm not sure the later 2 are in the wild (well ignoring the book mentioned there which was referring to humans).

There are a few other cases mentioned there not mentioned here yet like big horned sheep and lichen. As well as cattle, sheep and sometimes horses with locoweed, although I guess for these you could dispute whether this counts as in the wild but it has given rise to a word wiktionary:locoed. It simplifies a bit but from the refs it uses, it's been sheep at least don't seem to get addicted [43] but cattle seem to learn the behaviour socially [44]. More info on locoweed and lichen is probably found in the other book it mentions which it uses as a source for that info Intoxication: The Universal Drive for Mind-Altering Substances ISBN 978-1594770692.

Also mentioned in the source I linked is an example of what the OP referred to namely wallabies consuming opium. The elephant thing is new, the posting is tagged with elephants but from what I can tell they aren't mentioned in it. (They are mentioned in the first book which seems to predate the dispute.) Nil Einne (talk) 20:41, 11 March 2017 (UTC)[reply]

Just to be clear, no part of my sigh had anything to do with the posts of people who posted references. Matt Deres (talk) 22:50, 11 March 2017 (UTC) [reply]

Our article on locoweed says that "some individual animals seek it out". -Arch dude (talk) 02:52, 12 March 2017 (UTC)[reply]

The chemistry of ice cream

Chemically, what is ice cream? How can ice cream be low fat? I thought the fat part of milk is required in ice cream production. Can coconut flesh be grounded up into a creamy texture and then frozen at slightly below zero Celsius by ice cubes and salt while the mixture is constantly mixed by shaking the bag? Is this how commercial coconut ice cream is made? Avocados are high in fat. Why are't they made into commercial ice cream? Why are coconuts, almonds, and soy used instead? 107.77.194.195 (talk) 16:30, 11 March 2017 (UTC)[reply]

Ice cream is your source. The so-called "low fat ice cream" used to be called "ice milk" because it had very little fat content. ←Baseball Bugs ^{What's up, Doc?} carrots→ 17:03, 11 March 2017 (UTC)[reply]

"Low fat" is a relative term in the US. For example, 2% milk can be marketed as "reduced fat" compared to whole (4%) milk and one-percent milk can be described as "low fat" in comparison. What is marketed as reduced fat icecream in the US is not the same as "ice milk" and the brand I buy (bought) seems to use carb-based emulsifiers to maintain a fatty texture that icemilk does not have. Now I am off to seek ice-milk.... μηδείς (talk) 17:49, 11 March 2017 (UTC)[reply]

While fat, or something that simulates fat, is required to avoid ice crystals and get a creamy feel, shaved ice is another approach. As long as the crystals are small enough, they aren't too annoying. As for avocados, they can be used, but do have a flavor, so only work with strong flavors, like chocolate, that would cover up the avocado taste. Vanilla ice cream made with avocados would taste like avocados, not vanilla. Bananas can also simulate the fat, so frozen bananas in a blender can make a passable dessert. StuRat (talk) 17:52, 11 March 2017 (UTC)[reply]

Most industrial produced ice cream today is simply foam, representing 30-70% air or gas. Foam guarantees a soft, creamy texture and ofcourse at the same time its very, very, very cheap. You may notice icecream today is always sold with a volume declaration and there is never a weight declaration.

Ofcourse if you could read "2 litres/700 g" you would not pay more then the equivalent for 2 litres of milk, which seems a common prizetag, because you woult assume there is ~0.5 litres of milk in that at best. Often there isnt even any milk in it at all and usually it only contais Propylene glycol, some cheap fluid, some cheap fat and lots of sugar, in a masterful, cheap mixture you can not distinct form pure frozen whipped cream. --Kharon (talk) 22:23, 11 March 2017 (UTC)[reply]

Not in the U.S. where ice cream must contain milkfat to be called "ice cream". [45] Rmhermen (talk) 02:00, 12 March 2017 (UTC)[reply]

Radium Fission

Is any radium isotope fissile?32ieww (talk) 17:30, 11 March 2017 (UTC)[reply]

See radium. StuRat (talk) 17:56, 11 March 2017 (UTC)[reply]

Does it answer the question? Dbfirs 18:25, 11 March 2017 (UTC)[reply]

Wikt:fissile defines the word as "capable of undergoing nuclear fission", so any radioactive isotope would seem to qualify. However, the OP may have meant it in a more restrictive sense, like "usable to make a nuclear weapon or power a nuclear reactor". StuRat (talk) 18:32, 11 March 2017 (UTC)[reply]

Well almost any substance can decay. Even protons decay eventually. See Fissile material. Dbfirs 18:36, 11 March 2017 (UTC)[reply]

Looks like Wiktionary may need to be updated to show this diff between Wikt:fissile and Wikt:fissionable. They are currently treated as synonyms there. StuRat (talk) 18:41, 11 March 2017 (UTC)[reply]

Before 1965, the American Nuclear Society decided that "fissile" should refer to "those heavy nuclides which can be fissioned by thermal neutrons". Dbfirs 18:43, 11 March 2017 (UTC)[reply]

Looking at Isotopes of radium, no isotopes of radium are listed as undergoing fission. Radium atoms with masses 221-226 can undergo cluster decay, which according to that article "is a type of nuclear decay in which an atomic nucleus emits a small "cluster" of neutrons and protons, more than in an alpha particle, but less than a typical binary fission fragment."--Wikimedes (talk) 19:56, 11 March 2017 (UTC)[reply]

Research question: What's in a typical carpet?

Someone suggested attempting to write an article at Wikivoyage on "Carpet Safari" for April 1st.

This got me thinking, as I wasn't sure what to put in such an article as I am not entirely sure what might be relevant.

So does anyone have a guidebook to what flora and fauna may be present in a typical carpet? ShakespeareFan00 (talk) 19:05, 11 March 2017 (UTC)[reply]

Not every question has an answer. Look up yurt, Persian carpet, and indoor-outdoor carpeting, as well as dust mite and nematode. A more specific question could be answered more specifically. μηδείς (talk) 19:19, 11 March 2017 (UTC)[reply]

Seek and ye shall find. See Your home is a jungle inhabited by 100 different species, What Lives in Your House (Besides You), 50 Interesting Facts about Carpets, and Uninvited Guests: Invisible Creatures Lurking in Your Home. Alansplodge (talk) 20:03, 11 March 2017 (UTC)[reply]

How indestructible are military dog tags? (morbid)

I was thinking about the metal ID tags that military personnel wear, as do some other extreme activity people, and was wondering, how tough are dog tags? House fires burn at about 1500-2000ºF, and stainless steel melts between 1600 and 2200º depending on type and thickness. So would it be more likely that (in the unfortunate event of a firefighter dying in a blaze) that their tags wouldn't survive, but would like warp or the letters would be smeared and thus of no use? Another possibility is that the metal could become malleable enough that a falling object could crush or deform the tags? Thanks L3X1 ( distant write ) 20:24, 11 March 2017 (UTC)[reply]

You should check your (false) temperatures.--TMCk (talk) 21:02, 11 March 2017 (UTC)[reply]

"In typical house fires, temperatures seldom reach 650 degrees C." Manual of Forensic Odontology, Fourth Edition edited by Edward E. Herschaft (2007) p. 46. Alansplodge (talk) 21:30, 11 March 2017 (UTC)[reply]

Which is 1,200F (so, not close to 2,500F, the melting point of steel, but at least let's keep using the same scale). Matt Deres (talk) 22:23, 11 March 2017 (UTC)[reply]

Most are made of iron steel sheet metal. Something suitable, like SAE 310S stainless steel, has a melting range of 1354 – 1402°C °C or 2470 – 2555°F °F. --Kharon (talk) 22:42, 11 March 2017 (UTC)[reply]

Thanks Kharon I didn't know that. L3X1 (distant write) 22:48, 11 March 2017 (UTC)[reply]

(edit conflict) Thanks for the feedback, I am fruitlessly trying to track down the Google search that gave me the stainless steel temp. But regarding house fires, 1200 is only the average. Chimney fires (which can spread to the house) can easily break 2000ºF^[1]. Also hot spots, and other structure fires can get lots hotter than 1100ºF, and while no department would send in firefighters, there is the possibility that they could of died while the fire was smaller, and the bodies were unable to be retrieved by other crews before the blaze intensified. So I'll take all this as: Yes, their indestructible unless something above average happens. L3X1 (distant write) 22:46, 11 March 2017 (UTC)[reply]

Chimney fires are not the type of house fire fireman put out and I don't think Santa is wearing a dog tag :)) --TMCk (talk) 23:11, 11 March 2017 (UTC)[reply]
...and "fireking" certainly not a reliable nor believable source.--TMCk (talk) 23:15, 11 March 2017 (UTC)[reply]

I must be missing something from you first statement "Chimney fires are not the type of house fire fireman put out". Fireman do put out chimney fires, and chimney fires can turn into attic fires which constitutes a structure fire. I'm not a firefighter, but I've seen chimney fires on STATter911.com, and it still is missing the point. The avg. house fire temperature doesn't exclude the fact that other types of structure fires could be closer to 2000ºF. But I've seen to have answered my own question, below the destruction temps of steel, dog tags are indestructible by heat. Above the melting point of steel, poof. Thanks for y'alls time.L3X1 (distant write) 23:23, 11 March 2017 (UTC)[reply]

The point is that chimney fires can be the cause of a "regular" house fire but it's not the ch. fire itself that is put out, and no fireman will crawl into a chimney.--TMCk (talk) 23:29, 11 March 2017 (UTC)[reply]

References

^ http://middlegeorgiachimney.com/services/chimney-fires/

Ice falling from aircraft

What happens to ice which falls off aircraft as a result of the aircraft's anti-icing systems activating? Does this ice eventually fall to the ground below, or does it get absorbed in air? If it were to fall from the ground at thousands of feet above the air, then it would probably be hazardous for whatever/whoever it strikes on the ground, right? 173.52.236.173 (talk) 23:46, 11 March 2017 (UTC)[reply]

Whether it's hazardous would depend on the size and shape of the pieces. A small piece would not carry much kinetic energy even if falling rapidly, and furthermore, it would also have a low terminal velocity. --76.71.6.254 (talk) 00:26, 12 March 2017 (UTC)[reply]

See Ice falls from aircraft.--TMCk (talk) 00:26, 12 March 2017 (UTC)[reply]

However, that page refers to two other reasons that ice may fall off, rather than anti-icing systems as in the question. --76.71.6.254 (talk) 00:34, 12 March 2017 (UTC)[reply]

Oh. I didn't know that de-iced ice falls different than non-de-iced ice.--TMCk (talk) 01:08, 12 March 2017 (UTC)[reply]

In reading De-ice, I'm not so sure your initial premise is likely. ←Baseball Bugs ^{What's up, Doc?} carrots→ 01:05, 12 March 2017 (UTC)[reply]

March 12

Is Earth getting bigger? If so, why?

Hi guys. In the NatGeo or BBC docus I see, all things historic (fossils, towns) are excavated from meters below the present ground level. The historic ages are mapped as per the depth of the excavation below ground level. This seems to point to the fact that the Earth is getting bigger. Is this the right perception? If it is getting bigger, how is that happening? Is it because of space dust or any other reason? Thanks. Lourdes 04:46, 12 March 2017 (UTC)[reply]

The ground in some areas tends to accumulate and uplift. Check your local cemetery and notice how flat-ground markers appear to be "sinking" due to vegetation and soil accumulation. ←Baseball Bugs ^{What's up, Doc?} carrots→ 04:50, 12 March 2017 (UTC)[reply]

(edit conflict) Earth isn't gaining appreciable mass, or at least that's not the reasons behind what you see in archaeological excavations. (In fact it's generally thought that Earth is slowly losing mass.) There are various ways for things to get buried: natural processes such as deposition of material from rivers or glaciers (as in the famous Gården under Sandet in Greenland), mounding-up of material as a city decays and is rebuilt (see Tell (archaeology)), and so on. Shock Brigade Harvester Boris (talk) 05:01, 12 March 2017 (UTC)[reply]

Also note that the depth/age evaluation relationship is always specific to that location, a particular depth is not universally of the same age everywhere. Various dating methods are used to determine the age of a particular layer at a particular location. Layers of great depths can also be revealed in mountains, because of the tectonic processes which formed them. PaleoNeonate (talk) 05:27, 12 March 2017 (UTC)[reply]

We also have an article on the falsified Expanding Earth hypothesis. PaleoNeonate (talk) 08:21, 12 March 2017 (UTC)[reply]

Maybe we should also point out that the material that accumulates on top ultimately comes from the interior of the Earth - either as sedimental material removed by Erosion and deposited on top by wind or water, or, in the case of organic material, as carbon that outgassed (mostly in the form of CO2) and was converted by photosynthesis into more complex molecules. It's a cycle, not a one-way street. --Stephan Schulz (talk) 08:45, 12 March 2017 (UTC)[reply]

Golden gun

In Scaramanga's golden gun, how is the breech kept closed during firing? In other words, what keeps it from backfiring in his face every time he pulls the trigger? 2601:646:8E01:7E0B:F88D:DE34:7772:8E5B (talk) 07:05, 12 March 2017 (UTC)[reply]

Golden gun, part 2

Although Scaramanga boasted that he "only needs one shot" to kill his targets, how is this possible with the dinky little 17-caliber gun that he had? Specifically, even if one makes a 17-caliber hollow-point bullet out of solid gold (which would increase momentum and thereby stopping power), and loads the cartridge with enough propellant to give the same muzzle velocity as for a standard 17-caliber bullet, would this give enough stopping power to reliably stop (let alone kill) a person with only 1 shot? 2601:646:8E01:7E0B:F88D:DE34:7772:8E5B (talk) 08:03, 12 March 2017 (UTC)[reply]

As part of the (fictional) narrative, he simply is that good (or claims to be). Killing in one shot with a BL 15 is not a mark of great skill. With a small caliber, you have to aim not just at the person, but at a particular part of the person. --Stephan Schulz (talk) 08:40, 12 March 2017 (UTC)[reply]

All right, I consider the original question answered -- but this brings up a second question: Is it possible, with a 17-caliber pistol (and one with a removable barrel, at that -- removable barrel = at least some free play between the barrel and receiver = less accuracy), to reliably hit a person's vital organs at anything beyond point-blank range? 2601:646:8E01:7E0B:F88D:DE34:7772:8E5B (talk) 09:33, 12 March 2017 (UTC)[reply]

[1] ttp://news.nationalgeographic.com/news/2005/12/1219_051219_drunk_elephant_2.html

[2] ttp://middlegeorgiachimney.com/services/chimney-fires/

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