How come this sentence works: 'Let me know if you’re available.'  But this one doesn’t: 'Let me know if either of you’re available.'  Because the second one doesn't work, there must be some sort of rule about where contractions are valid. What is it?
I often hear people saying that "I am" is the shortest sentence in the English language.  I know that there are also discussions about sentences using the imperative mood such as "Go." that would be shorter, but my question is this:  Why would we (the people saying "I am" is a full sentence) not accept "I'm" as a complete sentence?  Is there some unwritten rule about contractions that says "I'm" wouldn't be correct?
Why does water take a "wet" path? Allow me to explain what I mean... ((I am asking this question in the physics section in hopes of finding a "physics" argument))  I shall make it clear what I mean by demonstrating an experiment...  Hold your hand upright with your index finger pointing up towards the sky. Now drop about 2-3 drops of water right on top of your finger. Water drop should (theoretically) stay there. Now tilt your hand ever so slightly towards one side. The water drop rolls down your finger down your wrist leaving a trail towards the tilted side right?  Now's here comes my question. Now if you bring your finger and the hand to the initial upright state and place another water drop on the same finger. Now we see that the water drop takes the same trail! Why does it happen?  My argument: The water trail which was previously left off reduced the friction in that path by filling the gaps between the molecules. Hence the new drop tends to slide more on that path and hence ends up travelling in it.  ((This "effect" is also observed when tear drops keep rolling down in the same path. But that could just be because that path is the steepest.)) Proving that $\lim\limits_{x\to\infty}f'(x) = 0$ when $\lim\limits_{x\to\infty}f(x)$ and $\lim\limits_{x\to\infty}f'(x)$ exist I've been trying to solve the following problem:  Suppose that $f$ and $f&#39;$ are continuous functions on $\mathbb{R}$, and that $\displaystyle\lim_{x\to\infty}f(x)$ and $\displaystyle\lim_{x\to\infty}f&#39;(x)$ exist. Show that $\displaystyle\lim_{x\to\infty}f&#39;(x) = 0$.  I'm not entirely sure what to do. Since there's not a lot of information given, I guess there isn't very much one can do. I tried using the definition of the derivative and showing that it went to $0$ as $x$ went to $\infty$ but that didn't really work out. Now I'm thinking I should assume $\displaystyle\lim_{x\to\infty}f&#39;(x) = L \neq 0$ and try to get a contradiction, but I'm not sure where the contradiction would come from.   Could somebody point me in the right direction (e.g. a certain theorem or property I have to use?) Thanks How to ssh into a server running on a home network, behind a router? Okay, so I have a PC in my home network, running Ubuntu on a VM with openssh server installed.    How can I remotely access it from another computer outside the home network, using the internet? What IP address do I use to connect to it? What kind of port-forwarding do I need to do? Out-of-control starship results in some crew members landing in a rebirthed universe? Do citizens migrate closer to their workplace within the town? By using the Path tool (F2, 7) I have found some laborers walking very long to eat at home or to warm up in winter.  If I build a house close to a Quarry or a Mine, will Stonecutters or Miners move automatically to this house to avoid long walking distances between the workplace and home?  Or can I assign some citizens to houses closer to their workplace? Setting up LVM Snapshot as a backup/restore point in ubuntu Relation between power and energy If I have an expression for the 'rated generator power' of a wind turbine, call it $P(t)$ how is the energy, that the wind turbine generator generate, related to the power $P(t)$?  So: $$E(t)=\dots$$ How to use z-index in svg elements? Notification for reviews shows way too many Since a , I see more than I should:    I see no reason to see 134 posts are awaiting review, when there is literally nothing I can do about them. I think it is a bug, because notification is meant as something that will make me act. When I know I usually can't, obviously I will start to ignore it.  If it's not a bug, please remove bug tag and explain how it is supposed to be useful, or how can I switch to only seeing notifications about things I can act on.  Note that apaprently there are no flags for me, neither. I see only stats, migrated, close, delete, there, as if there was no flags waiting:    If you expect us to click on it every few minutes  just to see personalized numbers next to queues, why don't you simply query for personalized numbers every few minutes and cache them for us? It should cost you similar, in database usage, and will save us a lot of clicking and frustration.  If all this number means is "there might be reviews, or not" or "for sure there are none"  it would be simpler just to hide "review" link in the second case. We don't need two links with the same function next to each other, thank you, one is enough, and meaningless numbers are only irritating. Global warming and air temperature The layman's question. Is there a maximum temperature that can be reached by air on Earth due to global warming? For example, one that would prevent living organisms from functioning? I read somewhere that with the increase of the sun's brightness by 10%, the average temperature on our planet will be 47 C. This, however, only for about 600 million years. Would global warming enable reaching such a high average temperature? Unparsed HTML shows on search result page When you search on any of the SE network sites, with a tag (so that a description is shown); it shows the tag info content box, with the highlight-search-term span elements.  For eg. I searched ; ; and the results are as shown:                  Notice the &lt;span class='search-highlight'&gt; boxes around searched tag terms. JavaScript post request like a form submit Splitting string into pair of characters in Ruby I have a string (e.g. "AABBCCDDEEFF") and want to split this into an array with each element containing two characters - ["AA", "BB", "CC", "DD", "EE", "FF"]. I've been modeling an F-15, but when I rotate the flaps on Y-Axis the Flaps offset from the wing and they look like they are about to fall out, so I end up correcting it by rotating in the X and Z-axis to align them correctly.  However when I rotate them back from the Y-Axis they look distorted again because I did rotations on the X and Z axis. I tried riding it, no help. I saw something about custom orientation to fix it but that was not clearly explained and it was done on an ideal plane that was (0,0,0); mine is pre-rotated on all axis.   I'll take scripts if needed and I'm using Blender 2.8.  When I rotate it on the Y-Axis:    Fixing it using X and Z rotation:    Rotating it back on the Y distorted it again:    Here's the wing with ailerons and flaps: Given $(a_n)$ with $a_n \geq a_{n+1} \geq 0$ show that if $\sum \sqrt{a_n a_{n+1}} < \infty \implies \sum a_n < \infty$ "Fatal error: Cannot redeclare " Independence of Gaussian variables In Ubuntu 20.04, on the desktop, there is a number of actions I wish I could do, such as, by order of importance :  use keyboard shortcuts such as select all, copy / paste. use drag &amp; drop with icons deactivate the &quot;mouse over&quot; highlight, and restrict the clicking area to only the icon, not the surrounding square  To put it simply, I'd like to have the exact same features as offered by the desktop of Ubuntu 18.04 (probably related to a specific version of GNOME, and not Ubuntu itself). Am I missing something obvious here? I actually see no reason why those actions are removed or deactivated on the desktop, since they all work in any Nautilus window. If I wrote something in plperlu, when would that module be reloaded?  Every time the function ran?  The first time it ran?  Does the Perl DLL get unloaded if it hasn't been used in a while, and then after that it'd be another module reload? Convergent or divergent $\sum_{n=1}^{\infty} \frac{e^nn!}{n^n}$? Any suggestion/hint, not the whole solution, how to determine convergence/divergence of $$ \sum_{n=1}^{\infty}\dfrac{e^n \cdot n!}{n^n} $$ I'm currently stuck.