Why doesn’t Quicksilver’s speed cause a sonic boom, lethal to anyone around him?
Why doesn't Quicksilver create sonic booms?
How can I sum two values and store the result in other variable? find() function in python2.7.5 Solder new RAM in a 2015 Retina MacBook Pro I know that the new rMBPs have no "user-serviceable" RAM. But is it possible to solder a new RAM chip onto a 2015 rMBP? Given that the technician doing this is able to install the new chip without damaging anything, would it work? Can I travel to Germany from a country different from the one I got the visa from? How to delete all lines that do NOT contain a certain word in Vim? In vim I can delete all lines that contain the word "price" with this  :g /price/d   How can I delete all lines that do NOT contain the word "price"? What makes frictional force the centripetal force of a car turning along a curve? As friction is the opposing force and acts anti-parallel so there is no component of frictional force towards the center,right? Then how can frictional force be centripetal force? How do I go about porting Ubuntu Touch to different devices? High CPU usage by "System" and "System interrupts" (caused by ACPI.sys) I have a laptop, which was running Windows 8.1 x64 without any problems. Now with Windows 10 x64 installed, Task Manager constantly shows unusual CPU usage by "System" and "System interrupts". To solve this, I already tried the following, without success:   Disabling and uninstalling all non-essential drivers. Installing newer drivers than the ones that were automagically installed (if available). Disabling/enabling fast boot option. Disabling all of the non-essential services. Sysprep. Resetting BIOS to defaults and various combinations of settings. Flashing BIOS to the latest available version. Clean install from the same media that I use for other PCs. Installing all of the updates offered in Windows Update to this day. Windows Performance Recorder / Analyzer.   I'm not very familiar with Windows Performance Analyzer, so I'm hoping someone here can point me in the right direction - what exactly should I look for, to figure out which device/driver is the culprit. Or, if there's any other approach to figuring out this problem?  For the brave souls, here's my  and a screenshot of the problem: Finding where source has branched from git cardinality of the set of $ \varphi: \mathbb N \to \mathbb N$ such that $\varphi$ is an increasing sequence I know that the set of functions $ f:\mathbb N \to \mathbb N$ is uncountable, but what if we consider only $f$ such that $f$ is increasing? I want to know if this set is countable D: and also the case of bijective and increasing (clearly if the firstone holds then this too). I think that it could be possible that it's countable What is the relationship between the focal length and field of view for an equal-area ("equisolid") projection fisheye lens?  Alternatively, what is the relationship between the 180-degree image circle size and the focal length for such a lens?  Ultimately I want to find the field of view of a Tokina 10-17 mm fisheye zoom at focal lengths other than 10 mm on APS-C (). Stein's lemma condition (Apologies if I break some conventions, this is my first time posting!)  I am working on proving Stein's characterization of the Normal distribution: for Z $\sim N(0,1)$ and some differentiable function $f$ with $E[|f'(Z)|] &lt; \infty$, $$E[Zf(Z)] = E[f'(Z)]$$ Writing the LHS expression in integral form and integrating by parts, I eventually obtain: $$E[Zf(Z)] = \frac{1}{\sqrt{2\pi}} \left[ -f(z) \cdot \exp \left\{ \frac{-z^2}{2} \right\} \right] \Bigg|_{-\infty}^{\infty} + E[f'(Z)]$$ Now I need to show that the first expression on the right hand size is zero. Intuitively, this seems clear because of the exponential term, but I am having trouble explicitly applying the condition on $f'$ to prove this rigorously. Any ideas? Why do not we ask negative questions without a contraction on the not after the verb? I have found multiple questions touching on this but not a single one that has a comprehensive answer. The information is all there but in little bits.     etc.   Exactly why is "Do not you sleep?" ungrammatical (except in poetry/with artistic license)? I understand that not can't contract after you: "Do you not sleep?" because not can only contract after a verb, and that it always does after do: "Don't you sleep?" but why does it (why must it) contract if it's placed after the verb in a question?   Don't you sleep? (common form) Do not you sleep? (ungrammatical) Do you not sleep? (less common form) How to install Windows 7 from the network? Is it possible to install Windows 7 (Current RTM Version) on a computer without using removable media like DVD or USB?  The first thing that comes to my mind is through the network, but I don't have experience of doing a fresh install of Windows 7 via the network.  How to install Windows 7 via the network without any removable media?  P.S. I know some may think that doing so, is just a waste of time and it's easier to do it with removable media, but in the current situation the target PC neither has CD/DVD Drive nor supports booting from USB. And in addition to that, the target computer is connected to the network via a wireless connection (I don't know if it will cause any problems with the installation). Displaying row/column of point in raster using QGIS? My Prof wrote that   $\sum_{n=2}^{\infty} n(n-1)x^{(n-2)} = \frac{2}{(1-x)^3}$  when $-1&lt; x&lt;1$  I do not understand where the above formula comes from. Can someone please explain the steps or provide a hint?   Thanks! I'm asked to show that $a^{61} \equiv a\pmod{1001}$ for every $a \in \mathbb{N}$. I've tried to tackle this using Fermat's Little Theorem and Euler's Theorem, but I can't even get started. My main problem seems to be the "for every $a \in \mathbb{N}$" part, because if it restricted $\gcd(a, 1001) = 1$ I would be able to factor out 1001 and try to show that it's factors divide $a^{61} - a$. I'm kinda lost here. Any help is appreciated. I am trying to rotate a dual monitor which is attached to the VGA output of my laptop. My system is Ubuntu 15.10.  However, here is the outcome I get when I use xrandr:  xrandr --output VGA-1-0 --rotate right xrandr: output VGA-1-0 cannot use rotation "right" reflection "none"   I have seen other posts on this subject, which all recommend editing xorg.conf. I have tried that, too. Here's my current xorg.conf file:  Section "ServerLayout" Identifier "layout" Screen 0 "nvidia" Inactive "intel" EndSection  Section "Device" Identifier "intel" Driver "modesetting" BusID "PCI:0@0:2:0" Option "AccelMethod" "None" Option "RandRRotation" "True" EndSection  Section "Screen" Identifier "intel" Device "intel" EndSection  Section "Device" Identifier "nvidia" Driver "nvidia" BusID "PCI:1@0:0:0" Option "ConstrainCursor" "off" Option "RandRRotation" "True" EndSection  Section "Screen" Identifier "nvidia" Device "nvidia" Option "AllowEmptyInitialConfiguration" "on" Option "IgnoreDisplayDevices" "CRT" Option "RandRRotation" "True" EndSection   Still, I keep getting the same error when trying to use xrandr to rotate that screen.   Is there another way of doing so? Determining "level" of an NPC ally for purpose of budgeting encounter XP Photoelectric effect intensity I understand the PE effect quite well but I'm failing to understand one thing. Intensity is the amount of energy per second incident to a given area.   So can you can increase the intensity by either increasing the electrical energy or making the area smaller? By increasing the electrical energy, what exactly is happening?  I assume that by increasing intensity you are increasing the number of photons incident to an area of the metal thus increasing the rate of photoelectric emission. But why doesn't increasing intensity via more electrical power lead to greater energy of the electrons, if by increasing intensity you are increasing the energy of the incident waves?  I understand the results but I'm trying to understand why the intensity works the way it is thanks