Name of a short sci fi story about 2 astronauts
Short story from many years ago: the ancient, brilliant, cruel race was Earthlings
One of my friends said that I would die if I drank distilled water (we were using it in a chemistry experiment) I gave it a go and surprisingly did not die.  I did a bit of  and found    It said that drinking only this kind of water could definitely cause death, as distilled water was highly hypotonic and it would make the blood cells expand and finally explode and ultimately cause death.  I wanted to know exactly how much of this water on an average was needed to be consumed to cause death. Mass retagger badge I've been busy retaggin questions since I got my retag privileges.  Shouldn't there be an incentive to retag wrongly tagged questions, other than the urge to do things right?  I'm mean, the only "badge incentive" for retagging are "Firs edit" (Organizer) and "Creation of a tag used 50 times" (Taxonomist). The first one is easy to get, and the second one, right now in SO is almost impossible to get without cheating, that's editing 50 questions with an unlikely tag. Taxonomist I guess, could encourage wrongly tagging.  Is this really a problem?  We could have an "Tagged 200 question" badge, so people go for that badge, instead of taxonomist. how to get output of a script/program into a file? Why are the holodecks on Voyager in use if they have energy issues? I'm watching the first two seasons of Voyager and various episodes have commentary on having energy limitations -- but we constantly see crew using extremely complicated holodeck simulations. Why would they allow use of the holodeck if they need to conserve energy? Is there a way to have Cycles skip rendering alpha? Eigenvalues of Householder matrix What would be the eigenvalues for a Householder matrix defined as: $H = I - 2 u u^T$? Can someone explain it  to me intuitively or with a simple proof? Is it possible to skip releases during an upgrade? I was on the tube and overheard a dad questioning his kids about maths.  The children were probably about 11 or 12 years old.   After several more mundane questions he asked his daughter what $1/0$ evaluated to. She stated that it had no answer. He asked who told her that and she said her teacher. He then stated that her teacher had "taught it wrong" and it was actually $∞$.  I thought the Dad's statement was a little irresponsible.  Does that seem like reasonable attitude? I suppose this question is partly about morality. Can i prevent/restrict standard user from installing/uninstalling software in Ubuntu 12.04 desktop? Prove that any two consecutive terms of the Fibonacci sequence are relatively prime Prove that any two consecutive terms of the Fibonacci sequence are relatively prime.   My attempt:    We have $f_1 = 1, f_2 = 1, f_3 = 2, \dots$, so obviously $\gcd(f_1, f_2) = 1$. Suppose that $\gcd(f_n, f_{n+1}) = 1$; we will show that $\gcd(f_{n+1}, f_{n+2}) = 1$. Consider $\gcd(f_{n+1}, f_{n+2}) = \gcd(f_{n+1}, f_{n+1} + f_n)$ because $f_{n+2} = f_{n+1} + f_n.$ Then $\gcd(f_{n+1}, f_{n+1} + f_n) = \gcd(f_{n+1}, f_{n}) = 1$ (gcd property).  Hence, $\gcd(f_n, f_{n+1}) = 1$ for all $n &gt; 0$.  Am I on the right track? Any feedback would be greatly appreciated.  Thanks, Filter to change the content of 404 page I have created custom rewrite rules. These rules now go to 404 page as expected. I can use action hook template_redirect to change the template matching query_var.  But I don't want to create separate template files as the page structure depend on the current theme in use. Rather I just want to change the content and title. I have tried change the content using the_content filter, but it seems the filter doesn't even get called for 404 page.  I also tried loading index.php template and then using the_content filter, but it also doesn't work.  Is there any way to achieve this? Short story about robots on a farm after losing communications, go out to rule the world Solve a congruence $1978^{20}\equiv x\pmod{125}$ How do I copy a property from an active object to selected objects? I was watching some videos on YouTube showing how to get the Duke O' Death in GTA 5, however what I have seen is sort of unclear.  Some people say you must be a returning player on GTA 5 to get it (what does this mean too BTW?), some people don't say that. Some people say you have to be Trevor, some people don't. Some say the time of day matters, some don't. And apparently you can buy it from Warstock website (I can't).   Can someone please tell me how to get it?! GTA 5 came with my PS4 (I didn't play it on PS3) if that helps. How to use AT commands in Android by 'root' the phone We have various Android devices from Spike, Samsung, Micromax, etc. How can we issue AT commands from Android to the modem? We searched in Google Play but did not find any app related to this.   suggests:     [F]irst you have to root the phone...`    How can we do this? Why can't we use entanglement to defy Heisenberg's Uncertainty Principle? In principle, it is possible to entangle any property of two particles, including speed and momentum. Surely then, this could be used to defy the Uncertainty Principle, which states that the momentum and position of a particle cannot be together measured with accuracy, but the more accurate one gets, the less accurate the other becomes:  $$\Delta x\Delta p=\dfrac{\hbar}{2}.$$  If one was to set up an experiment where two particles are entangled, one could then measure the position of one particle with great accurary at the same time as measuring the momentum of the other particle with great accuracy, which would mean that, as the two particles are entangled, one would then know the momentum of the particle they measured the position of.  Therefore, the Uncertainty Principle would have been defied, as both momentum and position have been measured with a high accuracy.  However, this can't be true, as someone would have thought of this before.  So why wouldn't this work? I am using a linux server which has 128GB of memory and 24 cores. I use top to see how much it is used. Its output is pasted at the end of the post. Here are two questions:  (1) I see that each of the running processes occupies a very small percentage of memory (%MEM no more than 0.2%, and most just 0.0%), but how the total memory is almost used as in the fourth line of output ("Mem:  130766620k total, 130161072k used,   605548k free,   919300k buffers")? The sum of used percentage of memory over all processes seems unlikely to achieve almost 100%, doesn't it?  (2) how to understand the load average on the first line ("load average: 14.04, 14.02, 14.00")?   Thanks and regards!  Edit:  Thanks!  I also really like to hear some rough numbers based on used percentage of memory to determine if a server is heavily loaded, since I once became the one who cramed the server without understanding the current load.  Is swap regarded as almost the same as memory? For example, when memory and swap are almost of same size, if the memory is almost running out but the swap is still largely free, may I just view it as if the used percentage of memory + swap is still not high and run other new processes?  How would you consider together CPU or memory (or memory + swap) usage? Do you become worried if either of them reaches too high or both?  Output of top：  $ top    top - 12:45:33 up 19 days, 23:11, 18 users,  load average: 14.04, 14.02, 14.00 Tasks: 484 total,  12 running, 472 sleeping,   0 stopped,   0 zombie Cpu(s): 36.7%us, 19.7%sy,  0.0%ni, 43.6%id,  0.0%wa,  0.0%hi,  0.0%si,  0.0%st Mem:  130766620k total, 130161072k used,   605548k free,   919300k buffers Swap: 63111312k total,   500556k used, 62610756k free, 124437752k cached    PID USER      PR  NI  VIRT  RES  SHR S %CPU %MEM    TIME+  COMMAND  6529 sanchez   18  -2 1075m 219m  13m S  100  0.2  13760:23 MATLAB 13210 timothy   18  -2 48336  37m 1216 R  100  0.0   3:56.75 absurdity 13888 timothy   18  -2 48336  37m 1204 R  100  0.0   2:04.89 absurdity 14542 timothy   18  -2 48336  37m 1196 R  100  0.0   1:08.34 absurdity 14544 timothy   18  -2  2888 2076  400 R  100  0.0   1:06.14 gatherData  6183 sanchez   18  -2 1133m 195m  13m S  100  0.2  13676:04 MATLAB  6795 sanchez   18  -2 1079m 210m  13m S  100  0.2  13734:26 MATLAB 10178 timothy   18  -2 48336  37m 1204 R  100  0.0  11:33.93 absurdity  12438 timothy   18  -2 48336  37m 1216 R  100  0.0   5:38.17 absurdity 13661 timothy   18  -2 48336  37m 1216 R  100  0.0   2:44.13 absurdity 14098 timothy   18  -2 48336  37m 1204 R  100  0.0   1:58.31 absurdity 14335 timothy   18  -2 48336  37m 1196 R  100  0.0   1:08.93 absurdity 14765 timothy   18  -2 48336  37m 1196 R   99  0.0   0:32.57 absurdity 13445 timothy   18  -2 48336  37m 1216 R   99  0.0   3:01.37 absurdity 28990 root      20   0     0    0    0 S    2  0.0  65:50.21 pdflush 12141 tim       18  -2 19380 1660 1024 R    1  0.0   0:04.04 top  1240 root      15  -5     0    0    0 S    0  0.0  16:07.11 kjournald  9019 root      20   0  296m 4460 2616 S    0  0.0  82:19.51 kdm_greet     1 root      20   0  4028  728  592 S    0  0.0   0:03.11 init     2 root      15  -5     0    0    0 S    0  0.0   0:00.00 kthreadd     3 root      RT  -5     0    0    0 S    0  0.0   0:01.01 migration/0     4 root      15  -5     0    0    0 S    0  0.0   0:08.13 ksoftirqd/0     5 root      RT  -5     0    0    0 S    0  0.0   0:00.00 watchdog/0     6 root      RT  -5     0    0    0 S    0  0.0  17:27.31 migration/1     7 root      15  -5     0    0    0 S    0  0.0   0:01.21 ksoftirqd/1     8 root      RT  -5     0    0    0 S    0  0.0   0:00.00 watchdog/1     9 root      RT  -5     0    0    0 S    0  0.0  10:02.56 migration/2    10 root      15  -5     0    0    0 S    0  0.0   0:00.34 ksoftirqd/2    11 root      RT  -5     0    0    0 S    0  0.0   0:00.00 watchdog/2    12 root      RT  -5     0    0    0 S    0  0.0   4:29.53 migration/3    13 root      15  -5     0    0    0 S    0  0.0   0:00.34 ksoftirqd/3 How to prove that $p-1$ is squarefree infinitely often, where $p$ is prime?  I had thought of using Dirichlet's theorem on arithmetic progressions.  The number of squareful values of $p-1$ less than or equal to $n$ is bounded by $\sum_{q}{\pi_{q^2,1}(n)}$, each term $\pi_{q^2,1}(n) \approx \frac{\pi(n)}{q \cdot (q-1)}$, and $\sum_{q}{\frac{1}{q \cdot (q-1)}} \lt 1$.  But using for example , the possibility is open that the error in each approximation for $\pi_{q^2,1}(n)$ may continue to increase with $q$, and since the sum runs up to $\sqrt{n}$, this argument is invalid.  Is there a more refined version of Dirichlet's theorem that can be used to circumvent this issue?  Or an entirely different way to prove this statement? Can someone pgfplots the following picture concerning confidence intervals? I've been trying to use the following code to produce it, but have no idea how to shade in the tails I am interested in. By the way, the line pointing the (100-C/2)% can be an arrow, does not have to be squiggly as depicted in the picture.   \begin{tikzpicture}[ every pin edge/.style={&lt;-}, every pin/.style={fill=yellow!50,rectangle,rounded corners=3pt,font=\small}] \begin{axis}[every axis plot post/.append style={   mark=none,domain=-3:3,samples=50,smooth}, clip=false, axis y line=none, axis x line*=bottom, ymin=0, xtick=\empty, ] \addplot {\gauss{0}{0.5}}; \addplot {\gauss{0}{1}}; \node[pin=70:{$\hat{\theta}_1$}] at (axis cs:0.57,0.5) {}; \node[pin=270:{$E(\hat{\theta} = 0$}] at (axis cs:0,0) {}; \draw[dashed] (axis description cs:0.5,0) -- (axis description cs:0.5,0.92); \end{axis} \end{tikzpicture}