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April 21

Mars the Orange Planet

Mars in natural colour in 2007

Mars looks orange rather than red. Why is Mars is called the Red Planet and not the Orange Planet? Could it be due to lingual reason or is it just easier to say according to a forum I saw? Yeah, I know Mars looks reddish as seen in the sky on Earth (that could've been the root origin of the Red Planet), but it looks orange when seen from telescopes or from spacecraft near it. PlanetStar 00:10, 21 April 2017 (UTC)

We've been calling it the red planet longer than we've had telescopes. Medieval and classical astronomical works describe it as red. Ian.thomson (talk) 00:13, 21 April 2017 (UTC)
Also, the word orange as a colour descripion is of relatively recent origin. (First used in English in 1512.) Mars has been associated with war and blood for millennia. {The poster formerly known as} (talk) 00:31, 21 April 2017 (UTC)
Interestingly enough, the planets from Mars to Neptune approximately follow the spectrum, with no green. Mars is red, Jupiter is orange, Saturn is yellow, Uranus is cyan, and Neptune is blue. Two questions are (1) why is there no green planet and (2) do you think planet 9 will be violet?? (For the latter of these questions, it would be nice if official info could be found sometime within 2017.) Georgia guy (talk) 00:38, 21 April 2017 (UTC)
You might be interested in Sudarsky's gas giant classification, as a start for searching literature on this. It is predicted that so called "Class V" (as in Class five) Gas Giants could be visibly green. I couldn't find you answer for whether a terrestrial planet could be green. Someguy1221 (talk) 01:40, 21 April 2017 (UTC)
Are you suggesting we're living in a gay solar system, Georgia guy? :) -- Jack of Oz [pleasantries] 05:13, 22 April 2017 (UTC)
I'm just pointing out a pattern in planet colors. I didn't even think about that question as something someone would ask me. Georgia guy (talk) 00:52, 23 April 2017 (UTC)
There you go then. -- Jack of Oz [pleasantries] 00:41, 24 April 2017 (UTC)
People don't usually argue subtle color distinctions for tiny dots of light. ("Mars is cinnibar? You're trippin', dude. It's more of a burnt sienna.") The thing that distinguishes Mars and a couple of stars from all the little white dots is that they're slightly redder, so "red" seems like a good thing to call it. See also psychological primary color. Someone please also link that theory where, if a language has a word for green, then it has a word for blue, or however it goes. --Trovatore (talk) 00:42, 21 April 2017 (UTC)
Basic Color Terms: Their Universality and Evolution. --Jayron32 01:05, 21 April 2017 (UTC)
That's it, thanks. --Trovatore (talk) 04:15, 21 April 2017 (UTC)
I believe the color of Mars is mainly from iron oxide (rust). Would you describe that as orange or red ? StuRat (talk) 05:12, 21 April 2017 (UTC)
No, I'd say it's brown. But we're supposed to provide references, so, using, let's see what some dictionaries say. Rust, the substance, is:
  • "reddish" according to Merriam-Webster
  • "reddish- or yellowish-brown" according to Oxford
  • "reddish-brown or reddish-yellow" according to American Heritage
  • "brown" according to Collins (There, see, I was right!)
  • "red" according to Macmillan
But, like gray, brown is a color that can only be perceived by contrast with something brighter (see Brown#Optics). Since a planet is seen against the night sky, it cannot be perceived as brown; if its surface is brown it will appear red, orange, or yellow. -- (talk) 05:56, 21 April 2017 (UTC)
Tovator and 76.71 have it. It's hard to make a photograph that captures the experience of looking up at faint pinpricks against a jet black sky, but some of the photographs on are passable.
Mars looks noticeably red compared to its surrounding stars. (Moreso with naked eye than with those photographs.)
Even in these photographs it's easy to lean in close to your monitor and contemplate the exact color, but in real life, when it's just a shimmering dot close to the edge of your vision... Well, with my eyes, I feel proud that I noticed it was red. ApLundell (talk) 14:37, 21 April 2017 (UTC)
  • Different people see borderline colors differently (citation needed). I always see Mars as orange (OR) with my naked eye. As for why it might be called red even if everyone saw it as orange, sometimes (citation needed) orange is subsumed in red—see for example redhead. Loraof (talk) 15:34, 21 April 2017 (UTC)
There's a difference in shade depending on if it's very bright like the August 2003 "perfect opposition" (best opposition for 284 years) or minimum brightness (where it approaches the dimness at which the naked eye doesn't have color vision) and also how close to the horizon it is and how hazy the sky is. Have you seen it under all these conditions? Sagittarian Milky Way (talk) 00:25, 22 April 2017 (UTC)
Like the Red Planet, the robin redbreast typically has orange plumage. --catslash (talk) 15:57, 21 April 2017 (UTC)
  • I find the premise absurd. I have added a true color image of the planet. If I were to characterize this as anything other than red, I would call it i peachy-red, and find it in no way orangish. μηδείς (talk) 02:22, 22 April 2017 (UTC)
But when I hold my set of coloured pens next to your image, it is almost exactly the same colour as the orange pen, and nothing like the red one. Wymspen (talk) 14:24, 22 April 2017 (UTC)
There needs to be a color called rorange. Sagittarian Milky Way (talk) 16:22, 22 April 2017 (UTC)
I just held up an actual fruit and a red sharpie pen to the image. It is certainly closer to an unsaturated red than orange to my eyes, but then our computer settings may be off. I'll certainly grant that Mars is not FF0000 in the RGB color system, but I have never seen an image that has made me think the planet looked orange. μηδείς (talk) 02:12, 23 April 2017 (UTC)
Careful, most "True color" images from space instruments are not quite true color. (And they often don't match each-other.) In this image's case the red channel is coming from OSIRIS's "orange" filter. which is 607-691nm, which is not the same as cameras you might get from your phone's camera. It makes for good images, but without knowing the exact details of how the image was processed, I wouldn't use it to win a debate. ApLundell (talk) 09:23, 23 April 2017 (UTC)

Constraint vs Restraint (Physics and Maths)

Dear Science Reference Desk,

"constraints" and "restraints" are terms used interchangeably, but it seems they have a clear distinction in Physics, Maths, ..., that I could not find on

Some help from the web:

This question fits the Maths Reference Desk as well.

Thank you for the consideration! (talk) 08:11, 21 April 2017 (UTC)

I think Wikipedia makes the distinction very clearly. See the disambiguation pages Constraint and Restraint. Loraof (talk) 15:42, 21 April 2017 (UTC)

Scientific knowledge

trolls gonna troll. --Jayron32 14:10, 21 April 2017 (UTC)
The following discussion has been closed. Please do not modify it.

What is always more powerful and more scientific knowledge, is it special knowledge or general knowledge?-- (talk) 10:35, 21 April 2017 (UTC)

Does special justice always being more juditional than general justice?-- (talk) 11:09, 21 April 2017 (UTC)
Does extraordinary justice always being more juditional than other justice?-- (talk) 11:31, 21 April 2017 (UTC)
Define those words you're using. ←Baseball Bugs What's up, Doc? carrots→ 12:19, 21 April 2017 (UTC)
I’m interesting, does special justice always creating a special knowledge and does general justice always creating a general knowledge in science?-- (talk) 12:30, 21 April 2017 (UTC)
What are you talking about? Do you have any examples? ←Baseball Bugs What's up, Doc? carrots→ 12:33, 21 April 2017 (UTC)
  • I'm afraid your command of the English language is not good enough to express yourself such that people can help you find answers to your questions. It's clear your native language is something other than English. If you tell us your native language, we can direct you to help in your own native language. --Jayron32 13:15, 21 April 2017 (UTC)
I just noticed that the Languages on the reference desk aren't filled in. It would be nice so we could easily direct this user to the Russian reference desk. (talk) 13:18, 21 April 2017 (UTC)
They are on the left side of the page Wikipedia:Reference desk. Not sure it will help. If this is who I think it is, he's a regular customer here and we should probably shut this thread down; it never goes anywhere in the years he's been asking these sorts of questions. --Jayron32 13:43, 21 April 2017 (UTC)
This series lacks the "is been" constructions typical of that regular customer. —Tamfang (talk) 23:55, 23 April 2017 (UTC)

Thanks. To my mind, extraordinary justice does always creating special knowledge which always being more juditional than general knowledge.-- (talk) 13:28, 21 April 2017 (UTC)

I'm sorry, but this isn't understandable as a statement in English. I suggest trying to see if there's a help desk on the Russian wikipedia. Shock Brigade Harvester Boris (talk) 13:34, 21 April 2017 (UTC)
The answer lies in the eye of the Beholder. Classic Intellectuals have always voted Philosophy aka "general knowledge" "King of Science". A General would probably choose "Rocketscience" as most powerfull instead. --Kharon (talk) 13:42, 21 April 2017 (UTC)
Is special troll different from general troll? Where can I turn to have my language understood? Are there any English-speaking forums? Bus stop (talk) 13:57, 21 April 2017 (UTC)
  • I think we've seen enough here. --Jayron32 14:10, 21 April 2017 (UTC)

Specialty or profession

What is always more important the specialty or profession?-- (talk) 18:24, 21 April 2017 (UTC)

Identifiable whisperers

Whispering tells me "... there is currently no known possibility to use speech recognition successfully on a whispering person, as the characteristic spectral range needed to detect syllables and words is not given through the total absence of tone".

So, how come we can (usually) quickly identify a whisperer whose normal voiced speech is already known to us? Not just family and friends, but I'd bet that if I heard a recording of, say, John F. Kennedy whispering something, I'd know immediately it was he. What is it that we have that voice recognition technology has not yet achieved? -- Jack of Oz [pleasantries] 23:41, 21 April 2017 (UTC)

Really? I can't. Maybe it's just me. I honestly can't distinguish whispers. Usually, the content and speaking style are more important than the voice. (talk) 00:44, 22 April 2017 (UTC)

There are two sources for that statement, one written in 2011, and the other undated. I note that when I search Google Scholar for speech recognition via whispers, I find this is a very active field of research, with hundreds of papers published on the subject every year. Certainly, there are many experts who think it is possible to do this, and they are trying to figure out how. This is totally outside my field of expertise, so I wouldn't even know who to begin citing. Someguy1221 (talk) 02:47, 22 April 2017 (UTC)

  • I suspect the signal to noise ratio is relevant. The timbre of a voice might be lost to the hissing characteristic of a whisper. I remember reading that thieve's cant avoided voiced sounds in order to be less noticeable or comprehensible to unwanted listeners. μηδείς (talk) 02:08, 23 April 2017 (UTC)

April 22

Making big chicken breasts

How do people make big chicken breasts? I don't get why a whole chicken's breasts look small while packaged chicken breasts look huge, and they are boneless and skinless! How do people make such big boneless chicken breasts? (talk) 00:42, 22 April 2017 (UTC)

How much reading do you want to do?
Here's Small Poultry Flocks from Texas A&M, including discussion of raising, feeding, slaughtering, and packing chicken in low volume.
Many years ago, I toured a chicken slaughterhouse - ISO 22000-compliant - and the answer to almost all of your chicken slaughter and packaging questions, in a modern developed industrial nation, will generally be "robots." Robots slaughter the birds, clean, scald, and defeather the birds, cut the major parts of the birds, brine the birds, (which causes the meat to swell up and look nice and juicy before they put it in plastic wrap at a store) ... I was astonished how very rarely a human was required to touch the live animal, the carcass, or the meat. Of course, in some places, there's still a lot of manual labor in meat processing. The great read, A Nickel's Worth of Skim Milk contains descriptions of home-raised, home-slaughtered chicken in the central United States during the Great Depression, when a lot of people grew their chickens in their own back yard because the economics worked out to be more cost-efficient.
The process of food-processing - in small scale or in industrial scale - is a fascinating topic. When I was a younger student, I used to hang around at the Poultry Science Department and read books in their library. You can find volumes on the care and feeding and preparation of chickens, if that sort of thing interests you. You can get advanced graduate degrees in chemical, biological, and agricultural sciences. You can make a souped-up, plump, healthy, safe, and delicious bio-chemico-chicken, and you do the same using "organic-" methods (whatever that even means!) Have you reached out to your local state university's agriculture outreach cooperative extension? Here's Agriculture and Natural Resources from The Ohio State University, and they surely publish a lot of locally-relevant information about the way chickens are raised, prepared, and retailed in your state.
Nimur (talk) 01:14, 22 April 2017 (UTC)
Poultry science department? There is a science department just for bird meat? (talk) 01:24, 22 April 2017 (UTC)
Indeed, I went to school at North Carolina State University, and we had a Department of Poultry Science. There is probably one such department in your local university, too. The broiler industry is a multi-billion dollar business employing large numbers of laborers, business-people, scientists, engineers, financial investors, and so on. Just in North Carolina, there are something like one billion agriculturally-raised birds, bringing in something like four billion dollars of revenue and generating many billions of more dollars in peripheral agricultural economic impact.
Through education, food production has become so well-refined as an art and science and business that you didn't have to catch and kill a chicken in your backyard this afternoon. Have you ever asked your elders if they have any stories about that?
And, bonus question - for fun and profit - if one billion birds yields four billion dollars of revenue - then, since you're surely great at math - can you figure out a way to raise an entire chicken, over its entire adult life, bring it to slaughter weight, and sell it for four United States dollars, and make money doing it? Suddenly, the problem doesn't seem so easy, huh?
Nimur (talk) 01:29, 22 April 2017 (UTC)
This means a profit of $4 per bird over the cost of raising and selling them, not a total sale price of $4/bird. μηδείς (talk) 02:11, 22 April 2017 (UTC)
Oh, is that so? Nimur (talk) 02:41, 22 April 2017 (UTC)
Our article on revenue is pretty clear that it is not equal to profit. Revenue is sales; profit is sales minus costs. Matt Deres (talk) 12:50, 22 April 2017 (UTC)
Never mind, for some reason I was thinking of turkeys. I can easily see a $4 revenue on a chicken. But they only take a few months to mature. μηδείς (talk) 17:38, 22 April 2017 (UTC)
They actually reach slaughter weight at 5 to 6 WEEKS. DrChrissy (talk) 17:44, 22 April 2017 (UTC)
NC State University has a College of Agriculture and Life Sciences,[1] so it stands to reason they would have departments on various types of agricultural plants and animals. According to this,[2] NC State is one of six universities in America that happens to have a poultry science department. ←Baseball Bugs What's up, Doc? carrots→ 01:42, 22 April 2017 (UTC)
Here is a list of the departments in NC State's ag school.[3]Baseball Bugs What's up, Doc? carrots→ 01:46, 22 April 2017 (UTC)
I expect that about every state that has at least one Morrill Land Grant university has a corresponding agriculture extension program. That would be ... every state in the Union, and Puerto Rico. Some might not break the departments up in the same way, but if you eat chicken in your area... your state probably sponsors education on poultry science. Nimur (talk) 01:52, 22 April 2017 (UTC)
The University of Illinois has a strong ag program as well. You may find it interesting reading.[4]Baseball Bugs What's up, Doc? carrots→ 01:50, 22 April 2017 (UTC)
Turkeys are no slouches either: "Companies involved in the production and processing of turkey provide 374,600 jobs that pay $21.4 billion in wages to families throughout the country, generate about $97.5 billion in annual economic impact, and about $7.5 billion in taxes." Bus stop (talk) 01:57, 22 April 2017 (UTC)
By golly! (Gobbley?) Those turkeys create more jobs and pay more taxes than that turkey in the White House! Nimur (talk) 15:18, 22 April 2017 (UTC)
Several of these poultry science departments and their equivalents around the world look at fundamental issues such as the the welfare concerns that are raised by creating these large breasts. See Broiler#Welfare issues. DrChrissy (talk) 16:49, 22 April 2017 (UTC)
Are you sure the breeds of chicken you're seeing alive and whole are the same breeds you're seeing in shrink-wrap in the supermarket?
Here's a research paper about the type of chicken you'll find in the supermarket. [5] Check out the illustration on page four.
That 1978 breed looks very similar to every live chicken I've ever seen up close. ... But look at that 2005 breed! It's huge! No wonder you can get such large chicken breasts in the store. ApLundell (talk) 08:44, 23 April 2017 (UTC)
And don't forget that photo was taken in 2005 so we have had a further 12 years of artificial selection since then. It may be of interest to some that the broiler industry follows a selection principle of "one day per year"[6]. This means they are selecting and breeding for birds that reach their slaughter weight one day earlier each year. It's hardly surprising they look nothing like layer hens which are the same species. DrChrissy (talk) 17:15, 23 April 2017 (UTC)

Would sleep deprivation, weed or drunkness change an eyeglass prescription?

Assuming ability to tell 1 or 2 is better is still there. Not that I plan to get glasses while sleepy, drunk and stoned. Sagittarian Milky Way (talk) 13:31, 22 April 2017 (UTC)

I am very short-sighted. I am aware that when very tired the eye muscles seem weaker, and focusing properly becomes much more difficult. That could have an effect during an eye test - if very tired you might end up with lenses which are slightly too strong for normal use. I cannot comment on drugs or alcohol - I don't use either. Wymspen (talk) 14:30, 22 April 2017 (UTC)
  • Marijuana definitely has a temporary effect on focus, which I can tell you from repeated direct experience. The reason it is prescribed for glaucoma is its effect on the pressure of the eye. μηδείς (talk) 17:30, 22 April 2017 (UTC)

Time travel paradoxes

Has it already been proposed that there would be no butterfly effect in time travel paradoxes because the present already occurred once and still exists with everyone else, independently of the traveller, while he is in the past? Particularly, in the grandfather paradox, all his offspring would continue to live in the present, without magically dying at the moment when he is killed in the past. This would also imply that if Hitler is killed in the past, the present where everyone, except the traveller, is living would also remain unchanged, because it's already a post-Hitler present. If, however, the time traveller decides to stay and live in the past, this entails some sort of parallel universe or spacetime where he would face a different outcome. Brandmeistertalk 14:24, 22 April 2017 (UTC)

Scientific arguments against fantasy seem so very pointless. Its already a contradiction to reality. Why should one try to argue further about contradictions inside such madeup fakelogic? Even the commonly cited parallel universe is a “a bunch of malarkey” realy. --Kharon (talk) 16:24, 22 April 2017 (UTC)
The notion of backwards time travel is strictly fictional, so you can make up any hypotheses you want to. ←Baseball Bugs What's up, Doc? carrots→ 16:25, 22 April 2017 (UTC)
See Time_travel#Backward_time_travel_in_physics. No one yet confirmed it's "strictly fictional". But that's offtopic. Brandmeistertalk 16:31, 22 April 2017 (UTC)
I believe the grandfather paradox proves that changing your own past is impossible. However, there's nothing in that to prevent going to another timeline identical to your own, and changing that. The many worlds hypothesis suggests that all possible universes should exist, including those just like ours but in the past by some period, but actually getting there is the part we have no clue about. StuRat (talk) 17:56, 22 April 2017 (UTC)
It is certainly good evidence that time travel is impossible. However a lot of things have been thought to be impossible and yet are true, physics seems somehow to be able to get through cracks in our logic. See for example the strange case of Quantum pseudo-telepathy. What they do is just simply impossible in classical physics. Dmcq (talk) 19:23, 22 April 2017 (UTC)
The need to cook up ways to get around the paradoxes is a good indication of why backwards time travel cannot work. One of my old math teachers liked to say, "If you start with incorrect assumptions, you're liable to get 'interesting' results." Starting with the assumption that backwards time travel is possible leads to absurdities. ←Baseball Bugs What's up, Doc? carrots→ 20:58, 22 April 2017 (UTC)
Well there already is a version that does work in Quantum mechanics and is a bit like the grandfather paradox, see Delayed choice quantum eraser. Dmcq (talk) 23:05, 22 April 2017 (UTC)
It's simpler to take the view that time doesn't exist in the sense that we tend to think about it in our daily lives, see e.g. here. You existing now, yesterday and tomorrow are just separate realities that exist in their own worlds. It's not that one world "evolves" into another world. It's just that given the information that describes the local state near some point in one world, we can compress that information in terms of information present locally in another world, and in turn information in that other world can be compressed further in terms of information present in yet another world etc. etc. We can do this in a continuous way, which yields the illusion of a time evolution. Count Iblis (talk) 19:28, 22 April 2017 (UTC)
Well it's nice to be so sure but I don't think the Measurement problem and how that relates to our reality has been at all satisfactorily solved yet. And information is conserved in Quantum mechanics, you can't compress it. Dmcq (talk) 22:54, 22 April 2017 (UTC)
Iblis thinks Slaughter-House Five is a documentary. --Trovatore (talk) 23:04, 22 April 2017 (UTC)
Information is conserved in unitary QM, so you need to keep track of all sectors of the wavefunction here. Whether you believe in collapse interpretations or subscribe to the MWI doesn't matter here. So, if you prepare a spin polarized in the x-direction and I measure the z-component, then my measurement outcomes do not contain any more information than was in the original state, but here you consider information present in the probability distribution over all possible outcomes. But if we focus on a particular branch of the wavefunction where I find a definite outcome, then I need to specify one bit of information more to specify my measurement outcome. Both in the MWI and in collapse interpretation this is true, in the former case this is to specify which of the two copies I happen to be, in the collapse interpretations this is to specify which way the wavefunction has collapsed (you then assume that the other branch doesn't exist).
Now, all the sectors together are the same as the original state up to a unitary transform, and that unitary transform can be re-interpreted as a change of basis in Hilbert space. Therefore what we experience as time evolution which inevitably has to involve gaining information (if I feel that a second has passed then that feeling can only exist due to information that wasn't there a second ago), which must be identified with us getting located in a narrower sector of Hilbert space. So, it's then not the unitary time evolution that is involved here, rather that our time evolved versions exist in sectors that can be found by expanding in a new basis and then finding the components in that new basis. Count Iblis (talk) 00:17, 23 April 2017 (UTC)
There's only one answer for what happens at a given point in spacetime. Those who have suffered precognition have reason to appreciate that there is only one future, and while it may happen "because" it was seen, it won't be changed. Wnt (talk) 01:55, 23 April 2017 (UTC)
A lot of people here are dodging the question and instead making pretty absolute, unreferenced statements on topics that the greatest minds of several generations have failed to find a consensus on.
The answer to the question asker's question is : Yes. This interpretation has been proposed, and is discussed in our article on Time Travel here : Time_travel#Interacting_many-worlds_interpretation
This idea shows up sometimes in fiction, too. Although it's also conflated with other interpretations. (Marty McFly still has memory of his original universe, but photographs he's carrying change.) ApLundell (talk) 08:29, 23 April 2017 (UTC)
Thanks. Brandmeistertalk 18:51, 23 April 2017 (UTC)

Feynman lectures authorship and copyright

Feynman lectures' copyright does not belong to him. I want to know what share of the text was written by someone else? Are there any Feynman lectures in audio or video that match the books? — Preceding unsigned comment added by Justpierrepit (talkcontribs) 15:30, 22 April 2017 (UTC)

Yes, the co-authors are Robert B. Leighton and Matthew Sands ([7]). This says that Sands encouraged Feynman to prepare and deliver the lectures, and to tape-record them. Then Sands and Leighton participated in preparing them for publication. Brandmeistertalk 15:51, 22 April 2017 (UTC)

Yes but how far is the"official" text from Feynman's words? Were the other contributors just correcting errors? Or would they write whole new sections? — Preceding unsigned comment added by Justpierrepit (talkcontribs) 16:00, 22 April 2017 (UTC)

Wikipedia has an article on that: The Feynman Lectures on Physics (I haven't read it, tho) 2606:A000:4C0C:E200:984A:CA94:A2BD:E53B (talk) 20:11, 22 April 2017 (UTC)

There are multiple versions of the work.
Have you read the preface to your print version?
Have you read the preface to the version hosted by Caltech?
That'll explain what you want to know. Here are detailed comparisons among editions.
By the numbers, between 2005 and the most recent edition, the work had more than a thousand point of errata, frequently of a typographical nature, but occasionally including errors of a scientific nature.
Comparing versions of difficult science and math books is exceedingly difficult. I have, for example, two or three different editions of Gray and Meyer. It's hard to read one edition, let alone to painstakingly compare my two copies side-by-side; I have occasionally tried this for a few books in my collection, and it never works well. Imagine if we scientists followed the philosophical lead of our scholarly religious forebears: we might gather all the different personal paper copies that we have all collected among each individual version of all of our Great and Important Books. We might gather these scrolls together in a monastery, where we might conduct Exegesis on all the great Texts, and we might form cabals and Communions and Ecumenical Councils to decide which textual passages are gospel - of the Original Truth - and which passages and phrases are canonical additions that fall outside of Feynman's core seventy-some chapters, but contain material that we believe to be factual truth and whose actual words and letters were originally inspired by The Author... and then we might even find some non-canonical chapters that we consider so wrong that we label them heresy and blasphemy...
This style of literate scholarly research is perhaps academically interesting, but it is is not how science works. We only began to make progress after we evolved away from that type of scholastic mindset. Today, we value empiricism over textual analysis. This is the scientific method.
Yet, you want us to apply monkish textual analysis to the works of Feynman on Physics? Blasphemer!
So: stop caring who wrote the book, forget about version-controlling the errata, and start judging its content by its core merit: is it readable? Does it teach? Is it factually correct? Is it current and well-written? Is the presentation understandable? Does it follow a reasonable syllabus? When you read the book, is it good? Equally importantly: is it better than the other books you could be reading?
When you critique the book by those questions, it is actually a really poor text on modern physics, and this is why nearly no actual physicist or physics educator really uses it. This is a statement that I have made, and cited on many occasions on this reference desk.
When in doubt about a claim made by Feynman or anyone else, why not conduct an experiment?
Overall levels of student performance on standardized tests of achievement may be relatively insensitive to variation in the content of classroom instruction resulting from differences in how teachers use textbooks. The unpleasant reality, repeatedly shown by many different experimental methods, is that you either understand physics, and you are good at it - or you don't understand physics, and you are bad at it, and we can't change this reality by giving you better resources and books. Physics and math in particular are subjects for which student performance is among the least sensitive to variations in presentation of content.
Nimur (talk) 16:48, 24 April 2017 (UTC)

Virtual urge to urinate after drinking water

Shortly after I drink a glass of water, I sometimes feel a little sensation towards the need to urinate then the sensation subsides after a while, even without urinating. I feel like the bladder gets filled in and then empties without urinating. What causes this and does anybody else experience this? PlanetStar 20:07, 22 April 2017 (UTC)

It can also be triggered by the sound of that water flowing into the sink. This is part of a the mechanism allowing us to postpone to urinate even when the bladder is full, allowing us to urinate at the right place and time. Such mechanisms have evolved in our early ancestors who had primitive brains, the signal to urinate can then involve simple triggers that we may not find so convenient anymore. Count Iblis (talk) 20:13, 22 April 2017 (UTC)
It could also be an example of individual psychological conditioning. I myself usually feel an urge to urinate when returning home and approaching my front door, even if I don't really need to: this has probably been conditioned in me by the frequent occasions on which I've returned home after drinking (beer) and did need to urinate – fortunately, I can usually suppress the urge (long enough) by particular mental imagery. {The poster formerly known as} (talk) 02:06, 23 April 2017 (UTC)

And what about the urge that begins 10–15 minutes after drinking water then subsiding around 30 minutes later. How is this possible? PlanetStar 05:52, 23 April 2017 (UTC)

I'm struggling to find a proper source, but I'm certain that while researching "breaking the seal" at some point, I read that there are two triggers to the sensation of having to pee: a full bladder and the sensation of the bladder filling. The first is a one-way drive: it just builds up until the pressure seems unbearable and you urinate. The second is not; if the bladder is not full, that sensation can pass as you get distracted by other things. I'll keep looking. Matt Deres (talk) 18:11, 23 April 2017 (UTC)
So you're saying that the secondary urge to urinate is the sensation of filling up the bladder but it subsides once it stops filling as long as if the amount of urine in the bladder is still within the comfortable level. What do you mean 'get distracted by other things'? The hyperlink to breaking the seal only talks about alcohol's effect on the urge to urinate. I don't drink alcohol, I drink mostly water. PlanetStar 02:23, 24 April 2017 (UTC)
I usually find I develop an urge to urinate when I feel like I need to pee. μηδείς (talk) 17:11, 24 April 2017 (UTC)

Is the longitude linear in time when I throw a ball in an angle?

Suppose I throw a ball on a large sphere in vacuum. Then the height of the ball is parabolic as a function of time, and I want to say that the longitude of the ball is linear in time. Is that correct? If not, how good is this approximation when I throw the ball not very far? (Say, tens of kilometers on earth). -- (talk) 22:02, 22 April 2017 (UTC)

Suppose you're standing 10 meters from the North Pole, and you throw the ball very close to the Pole. As it passes by, the rate of change of longitude with respect to time will be very high. In fact, you can get it arbitrarily high by throwing the ball arbitrarily close to the Pole. Whereas it will not be so high at the moment it leaves your hand.
So in principle, no, it is not linear. But at ordinary latitudes and for reasonable distances, it's going to be pretty close, because although the ball's vertical component of velocity slows as it approaches its apex, the horizontal component remains constant. Well, almost constant. See elaboration below. --Trovatore (talk) 22:07, 22 April 2017 (UTC)
And what if we throw the ball such that the trajectory stays at a constant latitude? Will the longitude be exactly linear as long as we don't pass the point of discontinuity?-- (talk) 22:20, 22 April 2017 (UTC)
You can't actually do that, except at the equator. The ball will remain in a single plane containing the center of the Earth, which means that its ground track will follow a great circle route, not a path of constant latitude. --Trovatore (talk) 22:22, 22 April 2017 (UTC)
I wonder if what you're really asking is, does the point on the ground directly below the ball move at constant speed? The answer to that is "almost". The ball's orbit looks like a parabola to us, but that's because we're only seeing a tiny bit of it near the vertex. It's actually an ellipse. If I recall correctly (orbital mechanics will probably give more precise information), the ball's orbital angular momentum with respect to the center of the sphere remains constant. That's almost-but-not-quite the same as saying its transverse component of velocity remains constant, because as it's going up, it gets slightly farther from the center, so you don't need quite as much transverse velocity for the same angular momentum. However, to keep the same speed projected to the surface, you would need more transverse velocity.
So bottom line, the point projected to the ground slows down slightly as the ball ascends, and speeds up slightly as it comes back down. But very very very slightly. --Trovatore (talk) 23:19, 22 April 2017 (UTC)
Oh, also: This is for a non-rotating sphere. If you want to do things in the coordinate system of a rotating sphere, you also have the Coriolis effect to worry about. --Trovatore (talk) 04:05, 23 April 2017 (UTC)

April 23

Climategate 2.0: New E-Mails Rock The Global Warming Debate

Can someone more knowledgeable about climate change than me please take a look at this article and confirm/debunk it? Climategate 2.0: New E-Mails Rock The Global Warming Debate A Quest For Knowledge (talk) 00:04, 23 April 2017 (UTC)

There is no need to debunk it. It is a fake news, garbage. --AboutFace 22 (talk) 00:48, 23 April 2017 (UTC)
It's not an actual Forbes article but a blog hosted on Forbes. The author is "the president of the Spark of Freedom Foundation," which is first and foremost concerned with "promoting free markets" -- i.e. corporate profit. The author "promotes affordable, abundant energy founded in conservative economic principles" -- i.e. he's more concerned with corporate profit and right-wing politics than science. The incident he refers to is covered here. Ian.thomson (talk) 00:57, 23 April 2017 (UTC)
The story is published in Forbes Magazine, quite a respected source, and specifically quotes known entities, opening it up to a libel suit if the claims, such as this one

“I’ve been told that IPCC is above national FOI [Freedom of Information] Acts. One way to cover yourself and all those working in AR5 would be to delete all emails at the end of the process,”writes Phil Jones, a scientist working with the United Nations Intergovernmental Panel on Climate Change (IPCC), in a newly released email.

are false. But of course one can simply say it is fake news without proof. Of course, since no proof of that is offered, the fake news claim can be dismissed without any need to disprove it. The fact that it is a blog does not legally relieve Forbes of liability for the claim. When it is retracted, then you can bring forth the "fake news" claim. μηδείς (talk) 00:58, 23 April 2017 (UTC)
It's not actually published, it's hosted. The Forbes Contributors articles are generally regarded as user generated content -- they are neither edited nor fact-checked. At most, they can be used to source the author's opinions on a subject but are useless for facts beyond that. Ian.thomson (talk) 01:07, 23 April 2017 (UTC)
So, you've retreated from this being fake news to being a statement of opinion. But it is clearly a statement of fact. When it is withdrawn or denied, then get back to us. Otherwise, it is what it is, a recommendation of how to hide from the public by circumventing the FOIA. μηδείς (talk) 02:02, 23 April 2017 (UTC)
Please point to where I actually called it "fake news." You have me confused with AboutFace 22. I said that it's biased and unreliable for anything beyond Taylor's opinions. Per the article I linked to earlier, there was a second release of emails, but the assessment of the situation in reliable sources was that the material, or rather the out-of-context misquotations cherry-picked by conspiracy theorists, was just a stunt and not worth looking over. The most that the Forbes blog could be used for (if there were secondary sources covering it) would be "this one lobbyist whose job focuses more on profit than the environment disagrees and uses it to rehash the same old ClimateGate conspiracy theory." Ian.thomson (talk) 07:30, 23 April 2017 (UTC)
Please note that this story was published in 2011. Do you remember a big Climategate 2.0 scandal then? Me neither. A few people aimed to stir up trouble. It got a small amount of traction, but lacked the impact of the original Climategate and was quickly forgotten. Dragons flight (talk) 07:45, 23 April 2017 (UTC)

Misleading title, failure of refdesk regulars to do basic research: The "New E-Mails" were leaked (and the Forbes article published) in 2011.[8][9][10][11] Yes they were really leaked (see the last ref I just supplied) and we already have an article on it: Climatic Research Unit email controversy. --Guy Macon (talk) 07:53, 23 April 2017 (UTC)

A number of them did but yes I would prefer more checking rather than trying to be first to reply like slashdot. And personally I wish people would stop referring to what lobbyists like James Taylor write as 'opinion' or that they 'disagree'. That is implying a feeling or thought on their part. The deliberate taking out of context of quotes is too extreme to have any doubt except that it is simply part of a propaganda campaign with no consideration for the facts. We do not know whether he actually disagrees with the facts or not only that they are not as important to him as his agenda. Dmcq (talk) 08:50, 23 April 2017 (UTC)
Note that at the very top of that article is says "Opinion". This is the indication they give us that it's just one guy's opinion, and not a fact-checked and peer-reviewed article. As such, it should be treated as authoritatively as if I said "garlic is icky". StuRat (talk) 16:59, 23 April 2017 (UTC)
So the only demonstrable fact is that it's the writer's opinion. ←Baseball Bugs What's up, Doc? carrots→ 17:10, 23 April 2017 (UTC)
Jeez, you put that straight after I give reasons why it should not be called an opinion. 'Opinion' is just something written at the top by Forbes so they can claim deniability and does not make it an opinion. It is propaganda. Dmcq (talk) 17:10, 23 April 2017 (UTC)
There's a fine line between opinion and propaganda. ←Baseball Bugs What's up, Doc? carrots→ 17:19, 23 April 2017 (UTC)
The difference is pretty clear here. It is the difference between a witness identifying someone he thinks was guilty of a crime, and them planting evidence on them that they committed a crime. One helps the law and the other perverts it. In this case a thought out opinion one way or the other would be something for people to consider. Taking bits out of context and knowingly misusing them to further his aims as a lobbyist is propaganda. Dmcq (talk) 17:25, 23 April 2017 (UTC)
There's plenty of propaganda to go around. Al Gore for instance is not a scientist but he is a propagandist. The same motivation that discredits corporate positions also discredits political positions. There is nary a difference between ignoring climate change for oil profits and promoting climate change for social justice. Neither are science. Science doesn't need protest marches. --DHeyward (talk) 17:37, 23 April 2017 (UTC)
I assume you are talking about the March for Science. I certainly agree with what it says about policy in the Scientific opinion on climate change "The natural and social sciences can play a role in informing an effective response to climate change. However, policy decisions may require value judgments". However what Trump tries to do is suppress the message and research to find out the facts. I think scientists are entitled to present the results of their research rather than be suppressed and gagged and unfortunately that now requires them to fight to support the integrity of their profession. By the way I don't see what climate change has got to do with social justice but yes I would consider a scientist who went about crusading about it as no longer a climate scientist but someone with a crusade. And there is a dark line a crusader can go across where they start twisting the facts rather than keeping to them and the person who wrote this bit went past there long ago. Dmcq (talk) 18:19, 23 April 2017 (UTC)
How do you imagine Trump has any power to suppress climate science? He can influence policy but he does not sit on any peer review boards. It is certainly not clear what constitutes an "effective response" to climate change or that there is any scientific consensus for any particular measure. Those strongly advocating for specific political solutions (taxes, credits, subsidies, etc) are not basing their arguments on scientific consensus because no such thing exists for any particular solution. Whether the EPA or NASA funds research is again a political decision, not a decision on the merits of the science. Politicians that use contemporary science to justify policies enacted to resolve projected outcomes don't have a particularly inspiring track record. --DHeyward (talk) 18:53, 23 April 2017 (UTC)
Most of that is about how it is up to the administration to set policy and I agree with that. It is sad I think that they are doing stupid things but it is a democracy and they were elected to do that. However on the initial question of what Trump can do to stop the science and gag researchers how about reading the section on that article at March for Science#Donald Trump and you'll see he has taken very effective measures. Canada did this sort of suppression under its previous administration, see [12] for instance, but of course Canada isn't anywhere near as important as the US in science. Dmcq (talk) 19:47, 23 April 2017 (UTC)
March for Science#Donald Trump is a prime example of synth. Opposition or support of Keystone XL is nor scientific. It is a political position. Scientists don't make infrastructure decisions. That whole section is filled with a synthesis that politically motivated environmentalists are backed exclusively by science and that is false. Supporters and detractors of Keystone are generally motivated by emotion, not science. If Keystone was a key platform for the March for Science, I'm afraid that they have been duped into marching for a political cause, not science. --DHeyward (talk) 20:19, 23 April 2017 (UTC)
I was talking about gagging scientists and suppressing research. That section does cover the sort of thing I was talking about. That it covers some irrelevancies is not to the point here, if you want to point that out there then please do as the march isn't something I have taken any interest in. Do you dispute that it points out that Trump is gagging scientists and is suppressing research? Do you deny that it was very effective in Canada and Trump is heading towards being successful in doing it in America as opposed to your supposition that there is no way he could do it? Dmcq (talk) 22:55, 23 April 2017 (UTC)
I think there is a difference between setting a political tone and "gagging." The EPA is fundamentally a regulatory entity. If it has funded research, there is nothing they can do to suppress information. It's not scientific suppression, however, to say the EPA cannot speak using the Governments voice. I've not seen where scientists say they cannot publish other than they cannot say it with the voice of a federal agency. Trump's biggest influence will be money allocated for research but not direct intervention. Saying he is suppressing scientific voices would imply there is a lack of integrity among those scientists as they choose to go along with it. Are you saying scientists don't have the courage or integrity to report their findings? --DHeyward (talk) 01:07, 24 April 2017 (UTC)
In an environment where research funding is halved it will not be easy for an EPA scientist to get a job in a related area. And yes in Canada most scientists did buckle under at least overtly. Scientists are not superhuman. Perhaps you are thinking about the marines when you talk about courage and integrity. Have a read of [13] for an idea of what federally funded scientists see as in store for them. It lasted nine years in Canada and Trump is much more up front and brazen about doing things like that. Dmcq (talk) 08:40, 24 April 2017 (UTC)
  • My apologies, Ian, for possibly conflating you with About Face, who simply makes an unfounded statement. I did take you as defending that position. But I think the attributed quoted email speaks for itself. I am not interested in debate, so I'll sign off on this topic. μηδείς (talk) 17:45, 23 April 2017 (UTC)

The OP asked us to confirm or debunk the "Climategate 2.0 Emails". Here goes. Jeff Sonderman at the Poynter Institute "What the Forbes model of contributed content means for journalism" interviewed Forbes's chief product officer Lewis DVorkin about how Forbes runs their blogs. I've indented major points with a bullet to make sure they stand out. The article says:

"When you practice incentive-based entrepreneurial journalism, you have to decide what to incent.

  • Stock market news and analysis site Seeking Alpha, which gets its content from contributors as well, pays them each a very straightforward $10 per thousand pageviews. You could also pay contributors based on the volume of productivity (per article, per word, etc.) or based on a subjective notion of quality.
  • Forbes has chosen to pay contributors based on unique visitors -- specifically, loyal unique visitors. An author is paid a certain amount (which varies and DVorkin would not disclose, citing privacy of individuals’ contracts) for each first-time unique visitor, but 10 times more for each return visit from that person during the same month.
  • Why is that good? It’s an all-in-one incentive to write well, to write often, to distribute and promote content and to build community. You don’t get a large number of unique people to come, and then come back again, without doing all of that well.
  • It also lets each contributor choose the most appropriate way to build her audience. One contributor might write a few deeply researched pieces; another might hammer out a ton of quick, timely pieces. Both can succeed.

HOW DO YOU ORGANIZE IT ALL? There are no centralized editors assigning the stories. There’s not even an editor aware at any given time what all the contributors are working on. How do you keep that from becoming a tangled mess?

  • Forbes hires each contributor to write about a specific subject, and requires them to stay in their lanes, DVorkin said. And Forbes won’t take on a new contributor if her proposed subject area isn’t desirable (read: relevant and/or profitable), or if the contributor pool on that topic is already saturated.
  • Another strategy that keeps the site focused is applying “the Forbes prism” across every topic.
  • “The beautiful thing about Forbes is, you can put almost anything through a Forbes prism,” DVorkin said. “The Forbes prism is about free enterprise, entrepreneurship and smart investing. Most business stories, and dare I say many cultural events, you can put through that Forbes prism. Because it’s always, at the end, about money.”"
The difference, at the end of the day, between Forbes's blog space and wikipedia (to give a handy example) is ethos. They sum their editorial policy up as "It's always, at the end, about money." We, on the other hand, are here to write an encyclopedia (not that this means the same thing to everyone, it doesn't). We have several core pillars telling us how to write an encyclopedia, but "Neutral point of view" is the one that keeps me here. If I were convinced that there was a successful overall slant to wikipedia, I'd leave, and I'd blow my whistle loudly. I've been tempted to do just that, but realized that I was being naïve about the same sort of internal politics I've seen everywhere - it's not just wikipedia that suffers from counter-productive agenda-driven behavior and power gaming. Even monasteries and convents have that, beacuse they're full of people, too.
So, Mr. Taylor can present these Emails on his Forbes blog with no oversight prior to publication. The New Yorker uses fact-checkers, which puts them in a minority among news outlets today. The fact checkers' job is to read an article submitted for publication, call up the folks the writer says he spoke with, and confirm that they told him what he says they told him (according to Richard Preston. a veteran contributor to the New Yorker).
Forbes candidly admits (a) there's no one watching their bloggers and (b) they're mainly concerned about who brings loyal visitors to their Web site, and they pay people, whey they pay them at all, on this basis.
The article in question doesn't show the actual Emails, it paraphrases them. The article doesn't show the Emails' headings with "bang paths" we can use to confirm that people named in the article actually said what the article says they did in Emails.
We do know the author runs an organization opposed to the concept of global warming, and writes for another such organization. We know he's paid by the number of loyal, unique visitors to the Forbes Web site and gets paid ten times as much if they visit the Forbes Web site to read what he has to say more than once. So he has an incentive to write articles that attract attention and get the people who read them to get their friends and acquaintances to read them, and come back to the Forbes Web site to read more of what he has to say.
Unfortunately, one reliable way to do that is to write what people want to hear - to confirm their cherished beliefs. It doesn't just work for Forbes, it works at the Huffington Post, at Breitbart News, and pretty much every major news outlet in the United States. We don't see much balanced reporting of news in this country any longer because it bores people, but if you tell people what they want to hear, they won't be as bored, and they'll read or watch the advertising on your programs, and you'll make more money. So, even if you'd seen this on CNN, Time, The Weekly Standard, Fox News or MSNBC, the same pressures to tell the audience what they want to hear apply.
I can't tell you this article is false, but I can tell you it doesn't prove any of the points the author makes, either. Even if it's not provably false, it wouldn't stand a chance of being considered reliable enough to serve as a source for a fact in one of our articles by itself. loupgarous (talk) 08:34, 24 April 2017 (UTC)

A fish like this

I think "Plusfish" is destined to become an internet meme, even if he does look like he's maybe not altogether "there" mentally. -Snow

Sorry about the bad drawing. I made it it two secs just to give you an idea.

So, would such a fish swim well? Is there any animal in nature with a similar body plan? Thanks. Anna Frodesiak (talk) 00:15, 23 April 2017 (UTC)

Assuming you're referring to the plus-shaped cross section, it wouldn't work very well due to the vertical plane limiting flex in the horizontal plane and visa-versa (cf: Shear modulus). Note that many fish have a vertical body-shape and flex back-and-forth, and a few (e.g.: flounder) have a horizontal body-shape and flex up-and-down. 2606:A000:4C0C:E200:984A:CA94:A2BD:E53B (talk) 00:47, 23 April 2017 (UTC)
The Humpback Turret fish, a boxfish
  • A lot of fish in the Tetraodontidae (puffer fish) family have a boxlike form, especially the boxfish. The Articles have pictures of many different species. These animals are mostly grazing coral eaters, and are built defensively, not for speed, but close in manoeuverability. μηδείς (talk) 00:50, 23 April 2017 (UTC)

Fine answers. Many, many thanks. :) Anna Frodesiak (talk) 04:56, 23 April 2017 (UTC)

@Anna Frodesiak: To address 2606's comment on swimming, these animals, like the horsefish, and Mola mola, all depend on fins, and not body flexure for propulsion. μηδείς (talk) 17:50, 23 April 2017 (UTC)

Thanks, μηδείς. Yes, they don't look very bendy. Cheers. :) Anna Frodesiak (talk) 18:25, 23 April 2017 (UTC)
They are actually a little more flexible than they appear, but it doesn't play a large role in their locomotion. However, note that, using the terminology of your original inquiry, I would not say that they "swim (particularly) well"; of course, in an ecological context, "well" is whatever serves the organism in its survival, but I took your question to be looking for insight as to the biomechanical limitations on speed and maneuverability; the sun fish is rather noted for lacking both. It's really hard to say without at least a little speculation, but my presumption is that your hypothetical fish with a body design incorporating two perpendicularly intersecting planes would be similarly limited in mobility. Unless one or the other planes was characterized by non-skeltalized tissue that in no way leveraged off of the other, then each plane would incumber the other from flexing as it does in most fish species to generate forward momentum--making it, like the sunfish, mostly dependent upon fins or some other extremity or locomotive mechanism. Also, insofar as it has greatly increased surface area, it is generating more drag with each motion. Note also that the absence of this kind of body design in any known species (despite a mind-dazzlingly complex array of variations "experimented with" by various species), speaks volumes to it's probable non-viability. Such a combination of features would have to have some kind of selective benefit, and I can't think of any--or at least none that aren't already better met by other adaptive traits realized in known species. Snow let's rap 18:59, 23 April 2017 (UTC)

Anna, I think I might have spotted a fundamental flaw in your fish design. The poor thing would have trouble moving up and down in the water. The dorsal fin could push the fish downward, but plus-fish does not have fins that could move it back upward! To achieve this, it would need a swim bladder, but I am wondering if the unusual body shape would allow for this, and even so, it would be a very slow method and not really suited for e.g. escape behaviour. DrChrissy (talk) 18:35, 23 April 2017 (UTC)

Hi, DrChrissy. I didn't even know that a dorsal fin could push a fish downward. I always thought that fin was to keep it going in a straight line. Anyhow, I always wonder what other lifefoms are like on other planets. I guess poor plusfish doesn't exist anywhere in the universe. That's probably best for it. Anna Frodesiak (talk) 18:41, 23 April 2017 (UTC)
I don't actually know whether the dorsal fin can be used to push a fish downward. I was imagining if it was held stiff and fanned from side-to-side, it would create a downward force. If you look at photos of sunfish, they appear to have only two fins, one on the dorsal surface and one on the ventral surface. I am envisaging that the dorsal fin can push the sunfish down and the anal fin push the sunfish up. Interestingly, the sunfish lacks a swimbladder. Unless plusfish can solve this problem, I think it will be destined for a life of swimming in straight lines at the same depth! - not much of a plus! DrChrissy (talk) 18:55, 23 April 2017 (UTC)
Good point. And its name really is an oxymoron. Anna Frodesiak (talk) 19:04, 23 April 2017 (UTC)
I must correct myself. Sunfish do have small pectoral fins. These would allow the fish to control their depth with simple forward propulsion from the other much larger fins and the tail. DrChrissy (talk) 19:22, 23 April 2017 (UTC)
Well, not so much, actually, at least not given the environmental context of most fish; insofar as the ocean and most waterways have currents of one variety or another, it wouldn't be moving in anything like a forward only/all at one depth path. It's merely that it could only influence its path in one way (and not very well at that). But this actually emphasizes the one ecological condition which such a shape may suit in an organism; drifting. Plus fish is decently (though not ideally) designed to catch currents. I should not be surprised if something like this general shape exists amongst the myriad morphologies of plankton, for example. Such a high dependence on drifting just doesn't happen to be a part of the ecological niche which fish generally inhabit though, owing to their size, amongst other factors. Snow let's rap 19:40, 23 April 2017 (UTC)
Underestimated Mother Nature! This design actually gave some engineers in fluid dynamics a huge supprise. See Mercedes-Benz Bionic with an drag coefficient of only 0.19 ! --Kharon (talk) 23:23, 23 April 2017 (UTC)
Did you mean that I'm underestimating mother nature with my reference to drag? If so, I think you may have not understood my observation. I wasn't stating that fish generally are constructed poorly with regard to decreasing drag; the truth very self-evidently runs in the other direction. In fact, I was specifically contrasting this sleek design of the archetypical fish with the proposed body design of Anna's plusfish and noting that there would be a lot of extra surface area (almost twice as much, in fact, relative to "one-plane" fish of a similar mass) that would create a lot of drag relative to the standard body design of most fish.
Or maybe you just meant that the engineers underestimated the efficiency of the design? If so, I tend to agree with you; I can't imagine why anyone, let alone an engineer, would be be surprised by that--if in fact they were. Aside from the fact that the efficiency of similar designs is well understood as a matter of basic fluid dynamics, of course a branch of life that is the product of billions of years of evolution in the niche of propelled aquatic locomotion has tended towards designs favouring very low drag coefficients. Snow let's rap 00:20, 24 April 2017 (UTC)
This source from the Benz 'Bionic'→Yellow boxfish article has a pithy description of the "boxfish swimming paradox" -- worth a read for those interested: [14] --2606:A000:4C0C:E200:984A:CA94:A2BD:E53B (talk) 00:56, 24 April 2017 (UTC) Modified:01:19, 24 April 2017 (UTC)
@Snow Rise: I was only trying to answer Anna Frodesiak's initial question if such a fish would swim well. I bet everyone underestimating mother nature. This seemingly "boxfish swimming paradox" additionally implies that this lovely, chunky, little fish was underestimated by everyone. --Kharon (talk) 10:44, 24 April 2017 (UTC)

Why are there two types of oxygen based on the agreement of spins in different orbitals?

According to our article on singlet oxygen, there are two different kinds: 1Σ+
and 1Δg. The first kind is distinguished from triplet oxygen, which is 3Σ
, based only on whether the spins of two electrons in two different orbitals are the same or not. But ... I thought orbitals (at least p orbitals...) were supposed to be orthogonal: px and py; pi bonds in one plane or in the perpendicular plane. Yes, the electron also has intrinsic spin, but ... I thought it was called a triplet because your observation might find each of the two electrons spinning one way or the other! What am I missing here? Wnt (talk) 03:00, 23 April 2017 (UTC)

Spin isn't a physical thing, or at least to a first approximation its angular momentum "direction" is a different sort of meaning than the coordinate sense of which way a p orbital is pointing. The px and py orbitals are orthogonal, but that doesn't mean the electrons in them have their spin axes defined as ±x vs ±y. So an electron in one orbital vs an electron in a different orbital are strictly limited to being "same spin state" or "opposite spin states" regardless of the geometric relationship between those orbitals. DMacks (talk) 03:33, 23 April 2017 (UTC)
Let's put it another way then: Why do two electrons in different orbitals with "up" spins have the ability to form a triplet, representing that their measured spins may either agree or disagree in a given measurement, but when one has an "up" and one has a "down" spin, they form a singlet? I would have thought that if an isolated "up" electron can have either a positive or negative effect on the observed energy of some interaction, the same would be true of a "down". Wnt (talk) 10:18, 23 April 2017 (UTC)
The state has to change sign under interchange of the two electrons, triplet states are symmetric while the singlet state is anti-symmetric. If you have two different orbitals, then you construct an anti-symmetric spatial part of the wavefunction, the spin part is then a symmetric triplet state, but you can also also have a symmetric spatial part and a singlet spin part. If you put two electrons in the same orbital, then the spatial part of the wavefunction has to be symmetric, the spin part will then be the singlet state. Count Iblis (talk) 19:29, 23 April 2017 (UTC)
I didn't quite follow that but then again it isn't my field. I think what was really being asked is why the singlet state is a higher energy state and so more liable to engage in reactions. And that leads I think to the question of why Hund's rule of maximum multiplicity holds, and in particular why parallel spins are preferred over opposite spins which seems a bit odd given the way shells are finally filled according to the Pauli exclusion principle. The article says something about that but really it seems to just come out of the calculations. Dmcq (talk) 23:27, 23 April 2017 (UTC)
This is definitely a clue, though I could use a reexplanation anyway.... The problem basically is that you're assuming it makes sense to me that symmetric and antisymmetric come out as singlet and triplet, and we're not there yet. Your explanation reminds me of how a meso compound with a plane of symmetry will not rotate light, while d- and l- enantiomers will. But still... it's not really the same thing. I can kind of gather how an anti-symmetric molecule, rotated 180 degrees, resembles itself and has the same observed spin. Are the two electrons are positioned in such a way that the magnetic effects of the spins necessarily cancel out? But if the molecule were symmetric like the enantiomers, I'd kind of expect it to be a doublet (like chiral molecules rotate light one way or the other). Instead the spins can cancel out or not cancel out in either direction, I take it. Is this on the right track? Wnt (talk) 02:29, 24 April 2017 (UTC)
My understanding is that, since charged particles in the Standard Model (in this case, electrons) can't have zero spin, the mutual cancellation of their magnetic effects is impossible, so invariance comes at play here - otherwise they would lose their electromagnetic properties (so maybe there's fine tuning to it as well). Brandmeistertalk 08:36, 24 April 2017 (UTC)
I don't really understand what you mean there. I feel relatively sure that when you have two electrons in an orbital their spins do mutually cancel out (I mean, they keep their spins, but the effect of them on anything else cancels out). Which is why we look at the effect of two unpaired electrons in the oxygen rather than, say, the 1s shell. But maybe I misunderstand what you mean.
There are forums that cover this, and the math involved: But they could be a lot more explicit about the direction of things. I mean, we have a well nigh unique resource at Wikipedia showing the complex Schroedinger solutions as rings of color [15]. It's possible to see, when the magnetic quantum number is maximal and takes the entire angular momentum from the azimuthal quantum number, how this angular momentum is pointed -- we can literally see the little bands of complex angular momentum laid out end to end to add up to however many Planck units of it are present. The electron orbits (blurrily) at distance n^2 and speed n, for a net increase of angular momentum per n, and in these maximal-m orbits we see those quantized units meet up around the ring neatly. It really seems almost classical, except for whatever "phase" is, a waveform. Things get more complicated when m is not maximal because the other momentum is in an unspecified direction, so it is shared between two axes. But for example you can see that if l=1, m=0 there are opposite lobes because that component of angular momentum tumbles just once around the center, while if l=2, m=0 the lobes on either side are the same because it goes through a whole cycle on the first 180 degree flip and another on the second. I feel like intuition could make all those shapes seem obvious with just a little more thought. But I don't know how to apply this to a molecular orbital. Wnt (talk) 12:32, 24 April 2017 (UTC)

The science of making vegetables taste like meat

I once soaked dried split peas in water and boiled it and drained it. The liquid was drunk. The solid was formed into a patty and sandwiched between two pieces of bread with mayonnaise spread on one side of bread. If it weren't for the obviously green color, that tasted like meat. If I were blindfolded, then I would have thought I was eating a real hamburger. Then, I soaked soybeans in water and boiled it and drank the liquid and kept the solid. The okara was formed into balls and placed into the oven. The balls tasted like grainy tofu. The closest non-animal product that tastes like meat to my knowledge is the shiitake mushroom, but I still can distinguish that and real meat. I once tried the Beyond Meat chicken strips. It did not smell like chicken, but it surely tasted like chicken! What is the cause of the poultry's distinctive aroma? What makes red meat taste like red meat? (talk) 22:21, 23 April 2017 (UTC)

It's because the liquid was drunk. If you'd waited for it to sober up, you wouldn't have been able to reproduce the effect. --Trovatore (talk) 23:00, 23 April 2017 (UTC)
Do you smoke tobacco heavily? Is your local beef that bad? You at least have found a cheap way of eating food that seems satisfactory to you, and may be healthier than eyelids and arseholes. Me, I make my burgers from the cows next door, grass fed, lean mince with 10% of the fat from the animal added back in. They bear no resemblance to peas or the rubbish you get in supermarkets or Maccas.Greglocock (talk) 23:09, 23 April 2017 (UTC)
No, I do not smoke. I have never smoked in my life. I may have secondhand-smoked before, because some people smoke too much indoors. Fortunately, those situations are rare. I'm just hoping that I won't get cancer from breathing in secondhand smoke. (talk) 23:25, 23 April 2017 (UTC)
You refer to hamburger? Are you really shure there is real meat in them?
Just kidding. Most industrial Meat is actually rather tasteless, very contrary to meat from wild animals btw., and the commonly known taste of meat is actually just fat and salt. --Kharon (talk) 23:10, 23 April 2017 (UTC)
Cashews contain a lot of fat relative to protein and carbohydrate content. Salted cashews would be high in fat and salt. No... they don't taste like meat. Neither do avocados. They taste like butter with a distinctive avocado taste. (talk) 23:43, 23 April 2017 (UTC)
The umami taste receptors on your tongue are responsible for "savory" taste, which is typical of meat and meat dishes. According to our article Umami#Foods_rich_in_umami_components, "Many foods that may be consumed daily are rich in umami components. Naturally occurring glutamate can be found in meats and vegetables, whereas inosinate comes primarily from meats and guanylate from vegetables. For example, mushrooms, particularly dried shiitake mushrooms, are rich sources of guanylate; smoked, fermented fish are high in inosinate, and shellfish in adenylate."
Foods other than meat which tickle the umami receptors include mushrooms, vegetables such as ripe tomatoes, Chinese cabbage, spinach, and celery and fermented and aged products like cheeses, shrimp pastes, fish sauce, soy sauce, nutritional yeast, and yeast extracts such as Vegemite and Marmite. loupgarous (talk) 09:10, 24 April 2017 (UTC)
None of them taste like meat. I still want to know what makes meat meat. Umami just provides one characteristic of meat, though. (talk) 12:44, 24 April 2017 (UTC)
Umami detectors on your tongue detect glutamate. Taste itself is only regulated by about 5 or so taste receptors (sweet, sour/acidic, bitter/alkaline, salty, and umami/protein). Of those, the one which is most prevalent in meat flavors is umami. --Jayron32 15:57, 24 April 2017 (UTC)
There's also the texture, smell, and even psychology (if you think you are eating meat it will taste more like meat). But, to me, it's not necessary to fool myself into thinking I am eating meat. After a while, you don't crave meat specifically, although you may have cravings for protein, which can be satisfied with beans, nuts, etc. StuRat (talk) 13:49, 24 April 2017 (UTC)
Yes, I know that texture and smell have to do with taste. But what are the chemical compounds? (talk) 13:55, 24 April 2017 (UTC)
(multiple EC) It depends what you mean by "meat". Impossible Foods claims that heme is a significant factor for ground beef is heme although there are obviously other important factors and in any case, since they have a commercial interest their claims need to be taken with care. I don't think our level of understanding is sufficient that we could list all the factors anyway, and it's likely to vary at least to some extent, from individual to individual (and of course from type of meat) Nil Einne (talk) 13:59, 24 April 2017 (UTC)
The dish you made with dried peas is a traditional classic - Pease pudding (or porridge, or pottage) - and has never been considered a meat substitute. It is usually made with yellow split peas, rather than green. Wymspen (talk) 10:47, 24 April 2017 (UTC)

April 24

History of science, fringe theories

Science is filled with fringe theories that were ridiculed and laughed at first, but then as the evidence slowly built it was accepted. Alfred Wallace said

I thus learnt my first great lesson in the inquiry into these obscure fields of knowledge, never to accept the disbelief of great men or their accusations of imposture or of imbecility, as of any weight when opposed to the repeated observation of facts by other men, admittedly sane and honest. The whole history of science shows us that whenever the educated and scientific men of any age have denied the facts of other investigators on a priori grounds of absurdity or impossibility, the deniers have always been wrong.

is this really true? Has any historian done a survey and determined the % of fringe/obscure theories that turned out to be correct? Money is tight (talk) 09:11, 24 April 2017 (UTC)

Whenever a fact contradicts a theory, either the theory falls or is modified to account for it. But the process can be slow, and well-established theories take time to change pending strong verification of the claimed facts. The nature of science is to fit theory to fact, not vice versa. Scientists may cling to pet theories well after there are substantial doubts, maybe hoping that even newer facta and even more comprehensive theories will prove the older one correct at least in certain scopes (and fairly obviously it must have been correct within its original scope:). But your question seems to be asking something a bit different...not "who had a theory even that was contracted by fact", but "who had a theory that wasn't supported until much later". DMacks (talk) 09:29, 24 April 2017 (UTC)
  • "the disbelief of great men or their accusations of imposture or of imbecility" would count as proof by authority and ad hominem fallacies, thus unscientific.
Western science is based on the ideas of measurement, open publication and independent reproduction of results. It doesn't make assertions of holding absolute truth beyond this. Part of that is that it has to recognise the possibility of future development, either subtlety, loopholes or even existing unrecognised error. So claims "by great men" that something is definitively known now and forever are just no part of this.
I'd be interested to see more of these "fringe theories" that were robustly rejected but are now accepted. Andy Dingley (talk) 10:14, 24 April 2017 (UTC)
Well there certainly have been lots of things like that, famous examples are Wegener's continental drift, heavier than air flight, and spooky action at a distance never mind the oldies like the Earth going around the Sun or phlogston or that disease was caused by microbes not miasmas or that disease could be spread by surgeons not washing their hands or the idea a vital force was unnecessary for life. However the conditions set are probably too difficult for any statistics to be got. How about all the silly theories that are dismissed and rightly so? We don't hear about the great majority of those. Who counts as a great man? etc etc really. Dmcq (talk) 10:38, 24 April 2017 (UTC)
The bold adverb in Wallace's quotation: the deniers have always been wrong. is so reckless and untenable that the claim must be dismissed as false. Alfred Wallace also insisted that faked "spirit" photographs were real and published "Vaccination a Delusion; Its Penal Enforcement a Crime (1898)", which hardly encourages one to believe everything he said. Blooteuth (talk) 10:40, 24 April 2017 (UTC)
Notice that Wallace relativizes the claim with a "on a priori grounds of absurdity or impossibility," Science is built by empirically passing claims by the filter of experience, not by rejecting what appears to be absurd. But yes, the "always" should better be a "sometimes" here. Hofhof (talk) 10:57, 24 April 2017 (UTC)
  • So when was heavier than air flight ridiculed as a fringe theory? After all, birds and bees.
A favourite in similar vein is that, "science said that humans would suffocate if travelling at the speed of a steam train". Yet this is an unfounded quote and appears to be either made up or misquoted. Dionysius Lardner was a Victorian scientist who did say that Brunel's Box Tunnel would involve trains accelerating to unfathomable speeds and flying apart, but that's because he was a single very poor "scientist" who no one, least of all Brunel, took seriously. He was the fringe theorist, if anyone.
Wegener never had a strong hypothesis for continental drift despite having found the evidence to prove it. He had the observational evidence from the surface to confirm that drift had taken place, but not the undersea measurements (made in the 1950s-1960s to support nuclear submarine navigation during the Cold War) that explained how it happened. He did guess at the right thing with mid-ocean ridges and ocean floor spreading, but that was later and extremely speculative. Even then though, he was unproven by science, rather than excluded. Chamberlin, one of his greatest critics said, "If we are to believe Wegener's hypothesis we must forget everything learned in the last 75 years and start all over again." (from memory) which is more about recognising how much of a shake-up would be needed and how it was still so unproven, rather than rejecting it as implausible.
We hear "science" claimed to have done many ludicrous thing, but we have to be careful that it actually did so. Andy Dingley (talk) 11:26, 24 April 2017 (UTC)
You can read the heavier than air statement and a few other bombastic things from Lord Kelvin at [16]. Have a look at Lord Kelvin for others like X-rays will prove to be a hoax. Dmcq (talk) 13:17, 24 April 2017 (UTC)
An argument based on "because Lord Kelvin said so" is no longer scientific, it's an appeal to authority. This is Kelvin, asked for his own opinion, giving it - but that's not a scientific hypothesis with a formal logic behind it. In particular for the flight issues, he's making an engineering claim, not a scientific one. Science sometimes finds an objective and fundamental limit, like the Carnot cycle or Betz' law, but engineering limits are subjective and based on the limits of knowledge today. Kelvin recognised, like the Wright brothers, that powered flight was currently impossible because of the limitations of steam engines (I believe he had already seen Maxim's work here, through their acquaintance Lord Armstrong) but (unlike the Wrights) he didn't then go on to find an alternative engine and construct a lightweight and powerful one, so he assumed that the limit was permanent and unsurpassable.
Famously Kelvin also stated that classical physics was almost all worked out by around 1900, and this view stood until Einstein's 1905 paper on the UV catastrophe. But again, Einstein followed a scientific route and examined a known problem, published a solution to it, and was then widely accepted by other physicists because he had given a reproducible experiment, conclusion and theory to explain it. Quantum theory makes predictions and quite simple experiments can demonstrate these, so other physicists readily accept them. Andy Dingley (talk) 14:54, 24 April 2017 (UTC)
Actually that bit about there being no more real science is almost certainly not his - see William Thomson, 1st Baron Kelvin#Pronouncements later proven to be false. Dmcq (talk) 16:33, 24 April 2017 (UTC)
It's difficult to do the counting. What counts as fringe/obscure? What counts as turned out to be true? And for whom?
For sure, we can say that science is not filled with fringe theories that turned out to be right. Cranks love to frame Einstein or Columbus as people who were laughed at.
Einstein was not some sort of outsider at his time, but this is by far not accurate. At the time of Einstein, a book called A Hundred Authors Against Einstein came out, trying to refute his work (many were not physicians, but philosophers), but he was not considered some sort of crank by the physics community. Some serious physicists believed him to be wrong, but still read, cited and tried to refute (with scientific methods) his theories.
I don't know of any source to corroborate or refute the claim that people laughed at Christopher Columbus. However, this is often claimed by cranks too. I suppose that he wouldn't have gotten the ships if people back then believed he was mad. Hofhof (talk) 11:15, 24 April 2017 (UTC)
Columbus was wrong because he underestimated sizes, and thought that he'd cross what we now know as Asia, the Pacific, America and the Atlantic all in the time it took to cross just the Atlantic. But his notion of a spherical, circumnavigable Earth was mainstream even at his time - although reading the published literature of the day, or even of that 2000 years earlier, would have given him a better size estimate. Andy Dingley (talk) 11:28, 24 April 2017 (UTC)
Rather than wrong, he was wrong on purpose. He was a cherry picker when presenting his project. He could have become a CEO today. He chose the smallest circumference of Earth, the farthest East distance and the the farthest West distance. And he got lucky that America was there. Hofhof (talk) 11:43, 24 April 2017 (UTC)
Columbus illustrates the problem coming up with exact numbers for this question.
People were absolutely right to laugh at Columbus, he was an anti-science crank. Mainstream science knew almost exactly how big the Earth was, based on measurements and hard math, but Columbus subscribed to a fringe belief based on religion. Nowadays we remember him as having been vindicated, but it's only true vindication if he arrived in Indonesia like he claimed.
The science of the time was right, Columbus had proved himself wrong. But most people remember it exactly opposite! ApLundell (talk) 14:28, 24 April 2017 (UTC)
That is a consequence of the myth of the flat Earth. Many people today think the contemporaries of Ferdinand Magellan expected him to fall off the world's edge or something, and by extension that all adventurers of the time, including lyin' Columbus and blood-bathin' Cortez, were heroes of enlightment. See for instance this article in the LA Times. TigraanClick here to contact me 15:49, 24 April 2017 (UTC)
What does this have to do with a flat Earth? No-one was claiming that. Andy Dingley (talk) 16:22, 24 April 2017 (UTC)
Yep not many people believed that - but you might like a laugh from some modern flat-earthers, or maybe it's a head-scratch of incredulity, whatever Flat-Earthers Have a Wild New Theory About Forests :) Dmcq (talk) 16:38, 24 April 2017 (UTC)
Myth of the flat Earth is not about flat-earther theory, but about the contemporary belief in the prevalence of flat-earther theory in the Middle Ages. But I could not find any backup for it having anything to do with Columbus being viewed as a pioneer of science, so I struck that part (and added a source). TigraanClick here to contact me 16:46, 24 April 2017 (UTC)
No, it's an article that explains your modern belief in a supposed medieval belief in a flat Earth is itself a myth - just as everyone else is saying about Columbus. Columbus knew the Earth was spherical, so did everyone else. Andy Dingley (talk) 17:26, 24 April 2017 (UTC)
Tigraan is saying that Columbus's reputation as a upholder and pioneer of science is a side-effect of the myth that his contemporaries believed Earth to be flat.
That makes sense. Columbus's mythical fearlessness at the risk of sailing off the edge completely evaporates when we remember that nobody seriously believed there was an edge.
He's remembered (because of the flat earth myth) as someone who challenged conventional wisdom and turned out to be correct. When in real life, the conventional wisdom was 100% correct, and challenging it was a stupid mistake that nearly cost his life and the lives of his crew.
ApLundell (talk) 18:02, 24 April 2017 (UTC)

Measuring a blow to a ball

I wonder if we only know the weight of the ball, distance and curve of the strike, we could know how the blow was. What physical details else would you need to know to compare strikes? Hofhof (talk) 11:47, 24 April 2017 (UTC)

Not easily. See inelastic_collision for a start. You'd also need to know what materials(s) the ball and bat were made from to determine how much deformation occurred for starters. (talk) 12:27, 24 April 2017 (UTC)
And also the bat's angle and speed. ←Baseball Bugs What's up, Doc? carrots→ 12:31, 24 April 2017 (UTC)
And wind direction and speed, temperature of bat, ball, and air, air pressure etc etc. You could at best make a crude estimate of force. Fgf10 (talk) 14:23, 24 April 2017 (UTC)
Let's ignore extreme cases (nano-size hydrogen balloon hit by a relativistically moving cat's whisker inside Jupiter's Great Red Spot). More like hitting a baseball. Can the stated three parameters give a reasonably accurate calculation of the energy imparted on the ball? How crude would that estimate be, in real Earth conditions? Think spherical cow in a vacuum. (talk) 18:47, 24 April 2017 (UTC)

Classic American Cars

I need an expert to find out the car models. May you please help me?--Grand Depot (talk) 13:24, 24 April 2017 (UTC)

I zoomed in real close and it looks to me like it says Chrysler on the hood (bonnet). (talk) 13:49, 24 April 2017 (UTC)
Which photo do you mean exactly?--Grand Depot (talk) 14:18, 24 April 2017 (UTC)
I think its a late-1920s Chrysler Imperial, not sure which exact trim package or model though. --Jayron32 15:45, 24 April 2017 (UTC)
I think the one in the bottom middle is the one with the logo and that it is a Chandler Motor Car. Dmcq (talk) 17:00, 24 April 2017 (UTC)
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