I have an external hard disk drive that I have set to drive F which contains some programs that I have shortcuts on the desktop to. I have a second external hard disk drive which I store my music on which is auto assigned to drive E, due to someone thinking that Australians love to have wings on power plugs for hard drives while power boards have each socket close together. I can have both of these hard drives set at the same time.  My music hard drive I normally only plug in when I synchronise music to my iPod, but on occasion when I unplug my music hard drive and plug my old one back in or at times when I turn on my computer with the music hard disk drive in, turn off my computer and turn it back on with my old hard drive, its drive letter gets switched to E.  I get annoyed having to always go into disk management and change the drive letter back to F when this happens so   Can I lock my hard drive to always be F? If anything else tries to be F, it can fail for all I care. Is there a batch file I can use that'll go though all the steps of Disk Management to change a drive's letter, that way I can set it up in the startup folder?   EDIT:      I get annoyed having to always go into disk management and change the drive letter back to F when this happens   I am just pointing it out in case someone missed it, because I already use Disk Management to change the drive letter back to F. If it stayed there then I would have a problem.
I have scripts that expect specific drive letters for hard drives. Windows sometimes assigns the different drive letters (e.g. I expected my Maxtor drive to be E:, but it's now F:, therefore my scripts will fail), depending on the order of how the drives are plugged into my laptop.  In Windows 7, how do I assign a permanent drive letter to a drive?
Can Blender render pngs with the background transparent? When I try to start Runescape I get an error message that says: CLassNotFoundException and lists Rs2Applet.class. How do I fix this so I can play? Say there are $m+n$ elements split into two groups ($m$ and $n$). The variance of the first group is $\sigma_m^2$ and the variance of the second group is $\sigma^2_n$. The elements themselves are assumed to be unknown but I know the means $\mu_m$ and $\mu_n$.  Is there a way to calculate the combined variance $\sigma^2_{(m+n)}$?   The variance doesn't have to be unbiased so denominator is $(m+n)$ and not $(m+n-1)$. Plotting the function $f(x)=x^{1/3}$ defined for any real number $x$ gives us:   Since $f$ is a function, for any given $x$ value it maps to a single y value (and not more than one $y$ value, because that would mean it's not a function as it fails the vertical line test). This function also has a vertical tangent at $x=0$.   My question is: how can we have a function that also has a vertical tangent? To get a vertical tangent we need 2 vertical points, which means that we are not working with a "proper" function as it has multiple y values mapping to a single $x$. How is it possible for a "proper" function to have a vertical tangent?  As I understand, in the graph I pasted we cannot take the derivative of x=0 because the slope is vertical, hence we cannot see the instantaneous rate of change of x to y as the y value is not a value (or many values, which ever way you want to look at it). How is it possible to have a perfectly vertical slope on a function? In this case I can imagine a very steep curve at 0.... but vertical?!? I can't wrap my mind around it. How can we get a vertical slope on a non vertical function? Two load icons simultaneously appearing in Android app This  confirms that the Android app is using two different loaders since last year, but just today I've noted that, at the questions page, it is using them simultaneously. I've never noted this, so I believe this bug was recently created.  I hope the following gif is clear enough to show the issue. Also, note that the bigger loader is "freezing".    SE Android App Version: 1.0.60 My Android OS Version: 5.0.2  Still observed in version 1.0.89 How to make a safe in vanilla Minecraft that locks and unlocks with a key? How can I make a safe/vault or something to lock my door that is very easy (as I am not that advanced with redstone) to keep people out of my house? Without mods? Why aren't there any common words for 'defecating' and 'urinating'? How to generate world files for raster X? Logging in as the same user multiple times in Remote Desktop Windows Server 2008 Quick question: I have a situation where I need to let multiple people on different PCs log into one server 2008 machine as administrator simultaneously over remote desktop. I have the CALs for it, it's just not set up correctly. When one user tries to log in, it boots the other out. What I need is to present to them a different session, just each as logged in as admin. Sorry for the slightly rambling post, I'm new here. Thanks! What is the optimum pattern to place crops in Minecraft? What factors affect soil hydration and crop growth time? What is the most efficient layout of dirt and water to grow crops? Access network share from within VBScript eg FileSystemObject If a Matrix Has Only Zero as an Eigen-Value Then It Is Nilpotent If you shine a light away from the center of a Schwarzchild black hole, will it stay still? $$ A $$  Light is travelling away from the absolute center of the Schwarzchild black hole (i.e. none of that spinning/stretching field) at $\ C $, and so shouldn't $\ \Delta C$ need to be greater than $\ C $ in order for the light to collapse into the black hole, therefore violating the relativistic limit of $\ C $?    It seems like light would just 'hover' right in the center of a black hole then. Because if it goes away from it, the event horizon pulls it back, and if it goes into it, the velocity change must be greater than $\ C $ which violates general relativity; so technically there's no way for the light to move away, and so it would just be still.  The thing is that the light must move at the speed of light or general relativity doesn't work. It's massless... But in the center of a black hole, if the above is true (it can't move or escape), then it is not travelling at the speed of light. So it cannot be still.  It cannot be spinning in a constant orbit either, because that would require velocity in an outward angle. And it cannot move in an outwardly fashion, only in an inwardly one.  Is it spinning in an infinitely decaying spiral towards the center?  If so what happens to it if and when it reaches the direct and complete center, i.e. The case of it being 'shot' from the center.    $$ B $$  If you shot light at an angle towards a black hole, but not directly to the center of it  then that light from the outside will eventually become the same as the light that I said was shot from the center to the outside; because in both cases, they end up in an infinitely decaying spiral.    If so it would end up exactly like the light in the above paragraph, so then we need to figure out what happens to that light to figure this one out, or vice versa.    $$ C $$  If you shot light directly towards the center of a black hole it would have no spiral to decay into, so therefore it must stop at some point in the center of a black hole. If it stops though, it loses it's momentum and violates general relativity again because it's energy "disappears".    If so then it violates conservation laws. So I'm assuming this simply is not true.    Is the light travelling into a black hole somehow still travelling at the speed of light, in every direction possible where that direction keeps it facing towards the center?  If so, why is there not a point at which the only thing left for the light to do is stay still, since all other paths would increase the distance between it and the black hole's center, and therefore become Case A. And if there isn't, what would happen if there was?  Also, if it's a time and observation answer where it supposedly takes and infinite amount of time for C to hit the center, wouldn't it be the case that the black hole is 'eating' all of the available light in the universe and keeping it in stasis?  Also, what happens in a Kerr black hole then? Does it just rip the field of time/gravity at an angle such that the light would never get closer than the center? Auto incrementing field based on groups within feature class? I am needing to auto increment a field based on groups within a feature class. I have 8 plots within a given polygon and I need to assign them an ID from 1-8 for each set of plots within each polygon. The polygon would have its own unique ID number to be used to group the plots.  I assume it would be an alteration of this:  rec=0 def autoIncrement():  global rec  pStart = 1   pInterval = 1   if (rec == 0):    rec = pStart   else:    rec = rec + pInterval   return rec How to participate in clan war instead of being a spectator I joined a new clan and now that the clan war has started I tried to attack but it says "Spectator can't attack". How do I get out of being a spectator (I haven't used either of my 2 attacks in the war). I went to the clan castle and the clan option and I selected "Yes I'll participate in this war" but nothing happens. If $ad$ and $bc$ are odd and even, respectively, then prove that $ax^3+bx^2+cx+d$ has an irrational root. $\displaystyle ax^3+bx^2+cx+d$ is a polynomial with integer coefficients. It is given that $ad,\,bc$ are odd and even respectively. Then prove that not all roots of the polynomial are rational.  It is easy to see that none of the roots are integer. But how to tackle the rational case? Any help is appreciated. Notation for functions vs. numbers I wanted to align a set of equations to left. I found on the Internet that you can do it easily with align* environment.   I found it here:   So I did it:  \begin{align*}  f(b)-f(a)=&amp;f((b_1,b_2,\dots,b_k))-f((a_1,a_2,\dots,a_k))=\ &amp;=\sum_{i=1}^{k}[f((a_1,\dots,a_{i-1},b_i,\dots, b_k))-f((a_1,\dots,a_i,b_{i+1},\dots, b_k))  \end{align*}   Unfortunately, I got bunch of red errors saying that there are missing $s. Why? Doesn't that align* environment provide a math environment already? Keyboard key stuck or not being recognized; how to fix This is an attempt to write a canonical QA for this issue, as per the Meta post:   I expect it to be periodically edited with the goal of becoming a comprehensive information resource.  I have a MacBook Pro that has a key(Shift, Return,   Command, P, etc.) that doesn’t respond when pressed or is stuck in the down position.    It's possible that my favorite beverage was spilled (or some other liquid damage).  It's also possible that I have no idea what happened.  It was working yesterday and suddenly today it's no longer working.  Is there any way to bypass or remap the key?  Can I  have the system ignore it completely?  (This question can also apply to external USB keyboards or the Bluetooth keyboards) how to glob every hidden file except current and parent directory I want to glob every hidden file and directory, but not the current (.) and parent directory (..).  I am using bash.  Observe current behaviour:  $ ls -a .  ..  ...a  ...aa  ..a  ..aa  .a  .aa  .aaa  a $ echo * a $ echo .* . .. ...a ...aa ..a ..aa .a .aa .aaa   I would like .* to behave like this  $ echo .* ...a ...aa ..a ..aa .a .aa .aaa   There is the shell option dotglob  $ shopt -s dotglob   that works in a way; now I can use * to glob everything (hidden or not) but not . and ..  $ echo * ...a ...aa ..a ..aa .a .aa .aaa a   but now I can't differentiate between hidden or not. Also, .* still globs . and ..  $ echo .* . .. ...a ...aa ..a ..aa .a .aa .aaa   Is there a way to make .* not expand to . and ..?