I remember something in The Deathly Hallows that Harry tries "Accio Hagrid" and the bike shoots towards Hagrid instead of the opposite thing that should occur. (Thanks Himarm for the quote)     “Hagrid!” Harry called, holding on to the bike for dear life. “Hagrid — Accio Hagrid!” The motorbike sped up, sucked toward the earth.    So what would happen if we said, let's say "Accio Eiffel tower" (Not Accio moon as it may cause death due to various factors :D ), assuming that we don't have enough power to summon such a big object. (I doubt only Dumbledore could manage that! ). Would we get sucked towards Eiffel tower as harry and the bike gets towards Hagrid. Wouldn't that then be a great way to travel? ( If we can somehow manage to prevent collisions, by putting some spell on ourselves or something?)
We know that Accio spell (aka ) has some limits:   It can be blocked (e.g. Harry couldn't Accio the Diadem in RoR in Deathly Hallows). Many more failures are listed on Wikia.   But what are the exact full rules and limitations governing the spell in Harry Potter world?   Distance?  Line-of-sight?  Knowing exact or approximate location?  Specificity of item (e.g. "Accio Broom" seemed to work for Weasleys in OotP to bring their locked-up brooms - why not just a random broom?) Types of Accio-able stuff? Can you Accio water? Lump of earth? Gases/liquids/etc...? Can you Accio based on jQuery selector (or an SQL where clause), for lack of a better description? E.g. "Accio the book that has the word 'Flammel'"? "Accio biggest green ball from this room"? Can you Accio ALL items of a kind? (the reason I thought of this whole question was seeing "Accio all guns" comment in ). Can you Accio vague stuff? ("Accio meal"). Other rules that can be inferred.   NOTE: While Wikia article has some of the info, it is clearly very lacking in details on specific rules based on specific instances in canon. I'm looking for a fully comprehensive, organized ruleset for the charm, not merely 1-2 tidbits in Wikia article.
Warning: Total photoshop newb!  I recently got a cool image of my fiancee and I holding hands and showing off her engagment ring. The backdrop is the beach:    I tried to trace an image using a combo of the laso and magic wand tools to select my target. Then I used that to pull out the target as another layer.  I then pasted in a background gradient.     Ended up with a really lame photoshoped looking picture. Notice the white lines where I didn't get the arms close enough and the choppy spots where I got too close.    So what's my main problem here?   Is their a way to bet a better cutout? Is their a blending tool that will make the background look more natural? both   I tried a dozen or so tutorials I found in google searches but they just don't blend these types of images together in any of them. Thanks in advance. How do deactivate plymouth boot screen? Lately, booting Ubuntu on my desktop has become seriously slow. We're talking two minutes. It used to take 10-20 seconds. Because of plymouth, I can't see what's going on. I would like to deactivate it, but not really uninstall it. What's the quickest way to do that? I'm using Precise, but I suspect a solution for 11.10 would work just as well. Showing that $a^n - 1 \mid a^m - 1 \iff n \mid m$ Let $a\ge 2$ be an integer. Show that for positive integers $m,n$, we have $a^n - 1$ divides $a^m - 1$ if and only if $n$ divides $m$.   I am having trouble showing this. I've seen a similar problem on here but it only shows one direction for the proof. I would like to see both directions.  This is what I have so far: Let $m = nq + r$, then $a^m - 1 = a^{nq + r}- 1 = a^{nq}a^r - 1 = a^{nq}a^r - a^r + a^r - 1 = a^r(a^{nq} - 1) + a^r - 1$. Since $0\le r\lt n$, $r = 0$ then $a^m - 1$ = $a^{nq} - 1$ so $a^m$ = $a^{nq}$ . Thus $m = nq$ hence $n\mid m$. My new 1,5 TB ext4 Hard Disk makes mysterious noises and fails to read and write. But not always. Sometimes it just works. But then I get those following errors. Does anyone know a solution for that or is my new WD Caviar Black 1.5 TB hard disk broken?  [  551.162286] ata7: SATA link down (SStatus 0 SControl 310) [  551.162294] ata7.00: link offline, clearing class 1 to NONE [  551.178223] ata7: EH complete [  551.190802] ata7: exception Emask 0x10 SAct 0x0 SErr 0x4040000 action 0xe frozen [  551.190807] ata7: irq_stat 0x00000040, connection status changed [  551.190811] ata7: SError: { CommWake DevExch } [  551.190818] ata7: limiting SATA link speed to 1.5 Gbps [  551.190822] ata7: hard resetting link   Update Mainboard P7P55D LE: How do I get my C# program to sleep for 50 msec? How do I get my C# program to sleep for 50 milliseconds?  This might seem an easy question, but I'm having a temporary brain failure moment! Question: Let $a, b \in \mathbb{R}$ with $a &lt; b$ and let $f: [a,b] \rightarrow [a,b]$ continuous. Show: $f$ has a fixed point, that is, there is an $x \in [a,b]$ with $f(x)=x$.  I suppose this has to do with the basic definition of continuity. The definition I am using is that $f$ is continuous at $a$ if $\displaystyle \lim_{x \to a} f(x)$ exists and if $\displaystyle \lim_{x \to a} f(x) = f(a)$. I must not be understanding it, since I am not sure how to begin showing this... Should I be trying to show that $x$ is both greater than or equal to and less than or equal to $\displaystyle \lim_{x \to a} f(x)$ ? Why when importing an obj file nothing appears even when zooming? I have opened a new blender file and deleted the default cube, then imported an obj file . I did not see any thing so i selected it and i zoomed ,nothing appears.In the outliner i saw the object name ,But in the info panel i see that there isn't any verts/faces/edges.  When i opened the obj file in a text editor i found Mesh data in it. I tired this in all blender versions (2.78c/2.78.5/7.9). Can any one help how to view the mesh? Why do Star Trek vessels always approach each other on parallel planes? Space is just open 3D space, right? In Star Trek, ships are always coming from somewhere else: different solar systems, galaxies, etc. However, when they meet, they always seem to be on parallel planes (facing each other).  In some episodes I recall seeing ships that were adrift (and they appeared facing a different trajectory). How can there possibly be some standardized reference plane in space? Do ships just choose to align with each other to be polite? Or perhaps when entering a solar system, the pilot, or navigation system aligns orthogonally with the local orbital axis? Modify obj after import using python I am trying to modify an object after importing it. This post is related to   import bpy full_path_to_file = "C:\\Users\\xyz\\Documents\\test.obj" bpy.ops.import_scene.obj(filepath=full_path_to_file) # create the material mat = bpy.data.materials.new('MaterialName') mat.diffuse_color = (1.0,0.0,1.0) mat.diffuse_shader = 'LAMBERT' mat.diffuse_intensity = 1.0  # get the object obj = bpy.data.objects['Cube']  # get the material mat = bpy.data.materials['MaterialName']  # assign material to object obj.data.materials.append(mat)   I wanted to add a material to the imported object but that is not happening. So I tried to scale it even that is not happening.  I realized that no operation is being performed on the imported objects. But the same operations are executing on the objects that are created (i.e. not imported).  Any help would be appreciated. Using crontab to execute script every minute and another every 24 hours Mathematical Prerequisites for QFT Does Hilbert's $\varepsilon$-calculus have any real problem when using for incomplete systems? Why do I have two docks in Ubuntu desktop (with GNOME 3) after installing Dash to Dock? What's going on here? I've installed the  on Ubuntu 17.10. Everything was cool, and as I was trying to hone and tweak the look of my desktop, at some point the shortcuts bar (dock?) on the left is duplicated.  (Click image to enlarge) The default, which normally disappears with Dash to Dock, is there underneath the one that usually shows up when I install Dash to Dock. Why? I've tried to go through the options for Dash to Dock, the GNOME Tweak Tool, and the regular Ubuntu settings, but I can't figure it out. How can I test for a player wearing specific armor? How can I test for a player that is wearing an iron helmet named "test1" and an iron chestplate named "test2" in Minecraft Version 1.12? I once already asked a very similar question; . But this is some what different.  I have the following code;  \documentclass{standalone} \usepackage{graphics} \usepackage{tikz,pgfplots} \pgfplotsset{compat=1.6} \begin{document} \begin{tikzpicture}  \begin{axis}[% width=3cm, height=3cm, scale only axis, every x tick label/.append style={font=\scriptsize\color{gray!80!black}}, xmin=0, xmax=20000, xlabel={$t$}, xmajorgrids, xminorgrids, every y tick label/.append style={font=\scriptsize\color{gray!80!black}}, ymin=0.0004, ymax=0.0012, ylabel={$\phi_{\mathrm{i}}(t)$}, ymajorgrids, yminorgrids, name=plot1]  \end{axis}  \begin{axis}[% width=3cm, height=3cm, scale only axis, every x tick label/.append style={font=\scriptsize\color{gray!80!black}}, xmin=0, xmax=20000, xlabel={$t$}, xmajorgrids, xminorgrids, every y tick label/.append style={font=\scriptsize\color{gray!80!black}}, ymin=0.2, ymax=1.2, ylabel={$h(t)$}, ymajorgrids, yminorgrids, name=plot2, at=(plot1.right of north east), anchor=left of north west]  \end{axis}  \begin{axis}[% width=3cm, height=3cm, scale only axis, every x tick label/.append style={font=\scriptsize\color{gray!80!black}}, xmin=0, xmax=20000, xlabel={$t$}, xmajorgrids, xminorgrids, every y tick label/.append style={font=\scriptsize\color{gray!80!black}}, ymin=0.0004, ymax=0.0012, ylabel={$\phi_{\mathrm{o}}(t)$}, ymajorgrids, yminorgrids, name=plot4, at=(plot1.below south west), anchor=above north west]  \end{axis}  \begin{axis}[% width=3cm, height=3cm, scale only axis, every x tick label/.append style={font=\scriptsize\color{gray!80!black}}, xmin=0, xmax=20000, xlabel={$t$}, xmajorgrids, xminorgrids, every y tick label/.append style={font=\scriptsize\color{gray!80!black}}, ymin=2000, ymax=12000, ylabel={$p_{\mathrm{i}}(t)$}, ymajorgrids, yminorgrids, name=plot5, at=(plot4.right of north east), anchor=left of north west]  \end{axis}  \end{tikzpicture} \end{document}   This creates the following plot:    I think there is to few vertical/horizontal spacing between the plots. I want to increase this. Currently I use x- yshift, this gives the following result:  \documentclass{standalone} \usepackage{graphics} \usepackage{tikz,pgfplots} \pgfplotsset{compat=1.6} \begin{document} \begin{tikzpicture}  \begin{axis}[% width=3cm, height=3cm, scale only axis, every x tick label/.append style={font=\scriptsize\color{gray!80!black}}, xmin=0, xmax=20000, xlabel={$t$}, xmajorgrids, xminorgrids, every y tick label/.append style={font=\scriptsize\color{gray!80!black}}, ymin=0.0004, ymax=0.0012, ylabel={$\phi_{\mathrm{i}}(t)$}, ymajorgrids, yminorgrids, name=plot1]  \end{axis}  \begin{axis}[% xshift=1cm, width=3cm, height=3cm, scale only axis, every x tick label/.append style={font=\scriptsize\color{gray!80!black}}, xmin=0, xmax=20000, xlabel={$t$}, xmajorgrids, xminorgrids, every y tick label/.append style={font=\scriptsize\color{gray!80!black}}, ymin=0.2, ymax=1.2, ylabel={$h(t)$}, ymajorgrids, yminorgrids, name=plot2, at=(plot1.right of north east), anchor=left of north west]  \end{axis}  \begin{axis}[% yshift=-1cm, width=3cm, height=3cm, scale only axis, every x tick label/.append style={font=\scriptsize\color{gray!80!black}}, xmin=0, xmax=20000, xlabel={$t$}, xmajorgrids, xminorgrids, every y tick label/.append style={font=\scriptsize\color{gray!80!black}}, ymin=0.0004, ymax=0.0012, ylabel={$\phi_{\mathrm{o}}(t)$}, ymajorgrids, yminorgrids, name=plot4, at=(plot1.below south west), anchor=above north west]  \end{axis}  \begin{axis}[% xshift=1cm, width=3cm, height=3cm, scale only axis, every x tick label/.append style={font=\scriptsize\color{gray!80!black}}, xmin=0, xmax=20000, xlabel={$t$}, xmajorgrids, xminorgrids, every y tick label/.append style={font=\scriptsize\color{gray!80!black}}, ymin=2000, ymax=12000, ylabel={$p_{\mathrm{i}}(t)$}, ymajorgrids, yminorgrids, name=plot5, at=(plot4.right of north east), anchor=left of north west]  \end{axis}  \end{tikzpicture} \end{document}     I want to know if there is a more consistent manner to do this. Prove that if $X$ and it's closure $\overline X$ are connected and if $X\subset Y \subset \overline X$, show that Y is also connected. Can anyone give me a proof of the statement that if $X$ and its closure $\overline X$ are connected and if $X\subset Y \subset \overline X$, show that Y is also connected?  Thank you. How to update Ubuntu terminal? How to update Ubuntu terminal? Is the gravitational constant $G$ a fundamental universal constant? I downloaded a file from the internet (I can link to it here, but in the interests of not annoying other users, I won't post the link), and I can't delete the file with the message:   You need permission to perform this action  You require permission from the computer's administrator to make changes to this file   Trouble is, I am the administrator and UAC is completely off.  If I go into the Properties/Security tab, I get the message   You do not have permission to view or edit this object's permission settings   Clicking "Advanced"/Owner, it says:   Current owner: Unable to display current owner.   If i try to change the owner, I get the same message:   Unable to set new owner on file  Access is denied. To which extent is general relativity a gauge theory?