Plot Details/Summary: This particular book was part of &quot;story time&quot; that the teacher read to the class when I was in elementary school back in the 70s, so I'm a little fuzzy on the details.  What I do remember is that some kids, and possibly a parent/guardian, travel to an alien planet.  The aliens there have a problem: sulphur/sulfur is a vital nutrient to them, and their natural source has somehow run out. I recall one of the kids - I think a little girl - solves their problem by giving the aliens her pet chicken.  The yolk in the eggs she lays have enough sulphur to sustain them.  I'm not sure if this was supposed to be a temporary fix until they found a more permanent source, of if they planned on breeding more chickens to make it a sustainable thing.   The humans return to Earth at the end, I think. Publication Details: The book would have come out no later than the mid-to-late 1970s.  It was very &quot;soft&quot; sci-fi, written for a young audience.  That's all I can remember.
I'm talking about at least two juvenile sci-fi novels, read between second and fourth  public grades (U.S.A.) which for me places them around 1956-9.  The protagonists are a brother and sister, presumably my (then) age. They are friends  with a single man, a scientist who has built a rocket ship. The scientist is little fey,  physically; a (relatively) large, round head, balding, short in stature and striking long,  thin hands and fingers.  The rocket ship's final preparation is to slop a viscous, clear gloop over EVERYTHING, inside and out from a pail with a paintbrush. In flight, there is an encounter with the moon, and a very small planet with (non-threatening) inhabitants not physically unlike the fey rocket scientist. The planet orbits either the moon or the earth, not the sun, and strangely, some kind of mushroom(!) theme runs through the books. Really.  That's it. That's all I got (I was nine at the most, fer chrissake). My recollection tells me there was concealment from parents, a particular name for the planet and people  and flight through a spatial fog. I mention these things separately because I am less sure  of them than the previous two paragraphs. The author was blissfully unrepentant of the laws  of physics:  Earth gravity on a micro-planet, fog in space and super-gloop to ready the  ricketiest rocket. Worked for me.  I'm guessing even Richard, my previous mentor/savior might not be familiar with these.  Anybody? Author, titles? Or do you just recognize one of these?
Why is it called a quadratic if it only contains $x^2$, not $x^4$? Should it not be bidratic or didratic etc? As it is common with people from my country, I have an immense difficulty with prepositions in English, especially with the use of in and on.   When the preposition indicates the position of the object it is a bit easier to decide which one to use, but as it requires thinking from me, I still say things like "I put the bill in the fridge", "my pencil is on my bag", etc, even though if I think about it, I would know how to say it correctly.  Of course, even in those cases where the preposition indicates position the decision is not always clear, as is the case for example with "on the bus" (you are not on top of the bus, you are inside the bus) or "he is in bed" (you are not inside the bed, you are on top of your bed).  Other cases are even less clear, and I believe there is no real rule to decide what should be said; the person should just know it. Two examples are "in a bad mood", "you are on my mind".  So my first question is whether there is really no rule to help me. The second question refers to two of the cases where I still don't know whether to use in or on:   good luck on/in your exam in/on the list   The last one is especially important to me, as I have asked a number of native speakers, and each time I get a different answer. The only consensus seems to be the case where you say "on top of the list". Apart from that, some people will say that I should say "his name is in the list" whereas others think I should say "his name is on the list". And yeah, a couple of people did tell me that I can use either.  Can someone help me? RAII and smart pointers in C++ In practice with C++, what is , what are , how are these implemented in a program and what are the benefits of using RAII with smart pointers? If $f(xy)=f(x)f(y)$ then show that $f(x) = x^t$ for some t Let  $f(xy) =f(x)f(y)$ for all $x,y\geq 0$. Show that $f(x) = x^p$ for some $p$.    I am not very experienced with proof. If we let $g(x)=\log (f(x))$ then this is the same as  $g(xy) = g(x) + g(y)$   I looked up the hint and it says let $g(x) = \log f(a^x) $   The wikipedia page for functional equations only states the form of the solutions without proof.  Attempt  Using the hint (which was like pulling a rabbit out of the hat)  Restricting the codomain $f:(0,+\infty)\rightarrow (0,+\infty)$ so that we can define the real function $g(x) =  \log f(a^x)$ and we have $$g(x+y) = g(x)+ g(y)$$   i.e $g(x) = xg(1)$ as $g(x)$ is continuous (assuming $f$ is).  Letting $\log_a f(a) = p$ we get $f(a^x) =a^p $. I do not have a rigorous argument but I think I can conclude that $f(x) = x^p$ (please fill any holes or unspecified assumptions) Different solutions are invited $x^TAx=0$ for all $x$ when $A$ is a skew symmetric matrix Let $A$ be an $n\times n$ skew symmetric matrix. Show that $x^TAx =0 \ \forall x \in \mathbb R^n$.  How to prove this? I have recently bought a Logitech M510 as my main mouse switching over from a magic mouse. I didn't realize missing horizontal scrolling would be such an issue, but apparently it is.   Now a mac does support horizontal scrolling by holding shift + scrolling, this is however amazingly slow.   I have the Logitech Control Center installed, which offers a few extra options, but nothing regarding the horizontal scroll speed. The scrolling speed options offered there only affect vertical scrolling.    Can the vertical speed be one setting and the horizontal speed another? When it comes to , I often read recommendations like "Use adb logcat to find some more details". Looking for a good way to backup all my apps including their data,  refers to adb backup and adb restore. In several places one can find ways to remotely do on an Android device with the use of , such as transferring files using adb push or adb pull, accessing the  via adb shell, and more. So ADB seems to be a good thing to have for an Android user.  But how to get this "ADB thingy" on my computer? Not being a developer, installing the entire  seems a bit overkill. Is there a more minimalistic approach available? Allow Documentation in other Stack Exchange communities I'm a Salesforce developer and would love Documentation to be available in other Stack Exchange communities. The reason is  a lot of Salesforce developers get help, especially newer ones like myself. The developer forums and documentation on  is mediocre. It would be nice to allow users to create their own and give pack on USB-C to MagSafe 2 Adapter I have a 2015 MacBook Pro with a MagSafe 2 charging cable. My wife has a new MacBook Pro from 2016 with USB-C. I was wondering whether I could technically (in the matter of electronic feasability) use her charging cable on my MacBook and vice versa with some sort of adapter / dongle, and, if so, where I would get one? How do I print an IFrame from javascript in Safari/Chrome Can someone please help me out with printing the contents of an IFrame via a javascript call in Safari/Chrome.  This works in firefox:  $('#' + id)[0].focus(); $('#' + id)[0].contentWindow.print();   this works in IE:  window.frames[id].focus(); window.frames[id].print();   But I can't get anything to work in Safari/Chrome.  Thanks  Andrew What is the rigor behind U subsitution? Find the number of natural solutions of $5^x+7^x+11^x=6^x+8^x+9^x$   It's easy to see that $x=0$ and $x=1$ are solutions but are these the only one? How do I demonstrate that?  I've tried to write them either:  $$5^x+7^x+11^x=2^x*3^x+2^{3x}+3^{2x}$$  or  $$5^x+7^x+11^x=(5+1)^x+(7+1)^x+(11-2)^x$$  and tried to think of some AM-GM mean inequality or to divide everything by $11^x$, but those don't seem like the way to go. Any hints? Why does my user number show up in the search box when clicking my profile information? Let $f$ be a continuous function. If $f$ is uniformly continuous then it maps cauhy sequence into cauchy sequence. Is the converse true? That is if $f$ maps cauchy into cauchy gives the uniform continuity of $f$. I think it's no. Can suggest a counter example How to remove the URL from the printing page? I want to remove the URL that gets printed on the bottom of the page.   like:  yomari.com/.../main.php?sen_n   How can it be omitted or prevent from getting printed?  To be more specific, is there any way I can prevent the page URL, date and the page title being printed along, while printing the web page? How to use "fit" to frame the nodes and labels I'm using the fit TikZ library to fit a rectangle around two nodes which include labels. However, the rectangle is only fit around the actual nodes, not about their labels:  \documentclass{article} \usepackage{tikz} \usetikzlibrary{fit}  \begin{document} \begin{tikzpicture}   \node [label=label1,draw] (node1) {Node1}; \node [label=label2,draw] (node2) at (4,2){Node2};  \node[fit=(node1)(node2), draw] {}; \end{tikzpicture} \end{document}     How to fit the rectangle also around the node labels? Is Tactical Down-Voting ever valid? Has anyone noticed any tactical downvoting of their, or other people, answers?  For example, in a recent answer to a question, my answer described a possible solution.  Shortly afterwards, another answer appeared following the solution I had mentioned.    I know that this is completely in the spirit of the site, however my answer had been down voted even though it was still as valid as it ever was.  Another poster also had his equally valid solution down voted.  There is no way of knowing the reason behind the down voting, as no comments were left, but I am suspicious as to the ethics behind down voting someone else's valid answer in the hope of making their own answer more prominent.  Are people really that desperate to gain reputation?  I have seen comments in other posts that suggest that tactical downvoting has occurred.  So, does anyone think that it is acceptable to downvote another post, even though it is still correct but may not provide a complete answer, to make their own appear more favourably? Vote can't be changed if answer is edited too quickly Is $7$ the only prime followed by a cube? Riddle (simple arithmetic problem/illusion) I'm not sure how well known this "riddle" is but here it goes.  3 people go to a restaurant, each buy food worth 10.00.  When they're done, they give 30.00 to the waitress.  She gives the money to the manager, manager says they paid too much, gives 5.00 back to the waitress.  She comes back to the table, gives a dollar back to each person and then puts the remaining 2.00 in her pocket for tip.  So now, each person has paid 9.00.  9.00 x 3 = 27.00.  Plus the 2.00 in the waitresses pocket is 29.00.  What happened to the 30th dollar?  So what's the issue with this way of calculating (since if you backward it works fine), that doesn't give us the correct result?