Bug with my meshes? Can't get my meshes to stop doing this and it's quite annoying
Cause of black artifacts in render? I was following  on creating a watch and noticed that when I rendered the watch, some pieces were messed up.  I'm new to 3D modeling and I've just learned Blender, I can't explain it well, so here's a picture:    Other examples:     I don't know if it's a problem with my World texture, the object, or the object's texture/material, so I can't even guess how to fix it. What causes this? Is it possible to fix it?
I have already proved Triangle Inequality $\lVert v+w\rVert \le \lVert v \rVert+\lVert w \rVert$ in vector space $\mathbb{R}^n$. However, I'm having difficulties proving the Reverse Triangle Inequality in the vector space.  I have started with   $$\lVert v \rVert^2=v \cdot v-w\cdot w+w\cdot w \le \lVert v-w \rVert+\lVert w \rVert^2$$ $$\lVert w \rVert^2=w \cdot w-v\cdot v+v\cdot v \le \lVert w-v \rVert+\lVert v \rVert^2$$  based on the Triangle Inequality but I don't know if it is correct. If this is right, I think I can go on with proving it the same way I would the normal Reverse Triangle Inequality. Transit Visa for Thailand How can I make a dispenser that has unlimited arrows? How is this command legal? "> file1 < file2 cat" Assuming file2 already exists, the command   &gt; file1 &lt; file2 cat   appears to be copying the content of file2 to file1.  But I cannot understand this structure.  I understand that "Nothing" is being directed to file1 (creating or erasing its content). Then the content of file2 is being directed to file1.  Why is cat after file2? How does it know to cat file2 if the operands are not in the correct order? An element not in a field extension Possible Duplicate:          Consider the field extension $\mathbb{Q}(\sqrt2)$. I want to show that $\sqrt5 \notin \mathbb{Q}(\sqrt2)$. If this were not the case, then we could write $\sqrt5 = a + b\sqrt2$ for $a,b\in\mathbb{Q}$. However, I do not see the contradiction here. Is there a better/easier way to prove this? Is there a number whose absolute value is negative? Script to remove Yellow(or any color) from layers panel? Why do we need to use int main and not void main in C++? How to disable pagebreak on \hline in longtable? How to disable pagebreak on \hline in longtable?  This is an example illustrating my problem:  \documentclass[12pt,a4paper,oneside]{letter}  \usepackage{longtable}  \begin{document}  \begin{longtable}{ | p{5cm} | } \hline Table header\\* \hline Lorem ipsum dolor sit amet, consectetur adipiscing elit. Mauris pharetra porttitor turpis, id egestas neque congue in. Nam sed lorem lorem, ac tristique tellus. Nunc ornare feugiat orci, a blandit turpis facilisis ut. Aenean pharetra ornare ante. Sed tempus leo in dolor eleifend placerat. Integer at enim augue. Ut nisl tortor, interdum ac porttitor ac, sagittis quis libero. Vivamus nibh metus, ornare vel pulvinar nec, fringilla nec orci. Maecenas mollis nulla a nibh fringilla nec convallis augue varius. Vestibulum ante ipsum primis in faucibus orci luctus et ultrices posuere   cubilia Curae. \\ Lorem ipsum dolor sit amet, consectetur adipiscing elit. Mauris pharetra porttitor turpis, id egestas neque congue in. Nam sed lorem lorem, ac tristique tellus. Nunc ornare feugiat orci, a blandit turpis facilisis ut. Aenean pharetra ornare ante. Sed tempus leo in dolor eleifend placerat.  Integer at enim augue. Ut nisl tortor, interdum ac porttitor ac, sagittis quis libero. Vivamus nibh metus, ornare vel pulvinar nec, fringilla nec    orci. Maecenas mollis nulla a nibh fringilla nec convallis augue varius.   Vestibulum ante ipsum primis in faucibus orci luctus et ultrices posuere   cubilia Curae. \\ \hline Table header\\* \hline Lorem ipsum dolor sit amet, consectetur adipiscing elit. Mauris pharetra porttitor turpis, id egestas neque congue in. Nam sed lorem lorem, ac    tristique tellus. Nunc ornare feugiat orci, a blandit turpis facilisis ut. Aenean pharetra ornare ante. Sed tempus leo in dolor eleifend placerat.    Integer at enim augue. Ut nisl tortor, interdum ac porttitor ac, sagittis  quis libero. Vivamus nibh metus, ornare vel pulvinar nec, fringilla nec    orci. Maecenas mollis nulla a nibh fringilla nec convallis augue varius.   Vestibulum ante ipsum primis in faucibus orci luctus et ultrices posuere  cubilia Curae. \\ \hline \end{longtable}  \end{document}   I'd like to have second header on page 3. I do not control table contents, so I can not do page breaks manually. Do any queries exist that require RIGHT JOIN, or can they always be re-written with LEFT JOIN?  And more specifically, how do you re-write this one without the right join (and I guess implicitly without any subqueries or other fanciness):   SELECT * FROM t1 LEFT JOIN t2 ON t1.k2 = t2.k2 RIGHT JOIN t3 ON t3.k3 = t2.k3 How can you find out which process is listening on a TCP or UDP port on Windows? Where do ultra-high-energy cosmic rays come from? Physicists have detected an amazing variety of energetic phenomena in the universe, including beams of particles of unexpectedly high energy but of unknown origin. In laboratory accelerators, we can produce beams of energetic particles, but the energy of these cosmic rays far exceeds any energies produced on Earth. So my question is, from where do these  come from? font-not-found error: font "HoeflerText" cannot be found -- LuaLaTex error! I am running this CV/Resume example from :   Here is a relevant fraction of the code:  \documentclass[10pt]{article} %!TEX encoding =  UTF-16 % See geometry.pdf to learn the layout options. There are lots. \usepackage[hmargin=1.25cm, vmargin=1.5cm]{geometry} %symbols - the ones you see on the left of the email and of the phone \usepackage{bbding} \usepackage{amssymb} \usepackage{eurosym} %Colors/Graphics \usepackage{color,graphicx} \usepackage[usenames,dvipsnames]{xcolor}  %Fonts and Tweaks for XeLaTeX \usepackage{fontspec,xltxtra,xunicode} \defaultfontfeatures{Mapping=tex-text} \setromanfont[Mapping=tex-text]{Hoefler Text} ...   So... when compiling with LuaLaTeX (part of MiKTeX on Windwos XP x64), I am getting the following error:  ... luaotfload | Font names database loaded: C:/Documents and Settings/Ampleforth/L ocal Settings/Application Data/MiKTeX/2.9/luatex-cache/generic/names/otfl-names .lua luaotfload | Updating the font names database: luaotfload | Scanning TEXMF and OS fonts... luaotfload | Font names database saved: %s  : C:/Documents and Settings/Ampleforth/Local Settings/Application Data/MiKTeX/2 .9/luatex-cache/generic/names/otfl-names.lua  !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! !  ! fontspec error: "font-not-found" !  ! The font "HoeflerText" cannot be found. !  ! See the fontspec documentation for further information. ! For immediate help type H &lt;return&gt;. !...............................................    l.28 \setromanfont[Mapping=tex-text]{Hoefler Text}   What is wrong? How can I install this font so LuaLaTeX is picking it up? Where to download? Any other thoughts about this? Can we use CAPITAL LETTERS to indicate actions? While designing for the web or the mobile applications, a natural free flowing text can be used for the general content, but when it comes to actions... can we use CAPITAL LETTERS. Polarization vectors of massive and massless particles After update, Ubuntu has now become PopOS I'm running Ubuntu 20.04.1 LTS. I was recently prompted to install an update from Ubuntu's GUI software updater, but I'm not sure which update. Now, I seem to have... a strange amalgamation of Ubuntu and PopOS all of a sudden? After booting up today, my desktop looks quite different:  It appears to be using Pop Shell, the tiling window manager that PopOS uses. The left-hand dock is gone. Looking at 'Appearance -&gt; Background' in Settings, the PopOS wallpapers are present. If I go to 'Appearance -&gt; Appearance', the light/dark theme chooser shows a visual with &quot;Pop!_OS User&quot; in it. The scrolling direction has been reversed. The icons are different. The Ubuntu Software Center is missing, but there's no &quot;Pop Shop&quot; in its place. The list goes on...  At the same time, a lot of my system is still very much how it was a few days ago when it was &quot;pure Ubuntu&quot; so to speak. My browser, IDE, files/folders, etc. are all the same... For context, I used to dual boot Windows and PopOS on a single SSD, but I've since wiped the drives I use (including resetting partitions). Now I use Windows on the SSD and Ubuntu on a new second drive... I can't imagine how anything from my old PopOS installation would carry over, let alone suddenly reappear inside Ubuntu after an update. EDIT: When running Software Updater again, it shows a full list of what it's trying to install: . When I try to install these packages, it fails midway through. That partially explains things... but why is this even happening? EDIT2: It is trying to install pop-gnome-initial-setup.deb which seems to conflict with gnome-initial-setup. Weird. Does it increase security if the CBC chunks of a AES-256 encrypted bytestream are uploaded to different clouds? I want to backup my data according to the 3-2-1 rule. I am already back up to 2 different drives (2 different systems) at home. In addition, I would like to use cloud storage (Google, Amazon, etc.). Considering the future weakening of cryptography by advancements in computing power (e.g. key guessing by quantum computing) I want my data to be as safe as possible because once it's uploaded it's prone to decryption in the future (i can't guarantee the data is deleted if I delete it from the cloud(s)). Does it increase the security of my data if I split the CBC chunks to let's say 2 clouds? Uploading the even-numbered CBC elements to e.g. Google and the odd-numbered elements to Amazon. Since one storage hoster is constantly missing the next part of the CBC-Chain (1/2 in total) shouldn't this increase security of the data even if the AES key is known by the hoster(s)? Reputation and inbox notification shows up again after refresh This was asked before too. .  Currently I am facing the issue of appearance of reputation notification in above toolbar.  I can see the reputation notification, for every page refresh even after clicking and viewing the notification.  current browser: Chrome Version 36.0.1985.143 m How can I prevent someone from resetting my password with a Live CD? Recently one of my friends came over to my place, within 15 minutes he hacked my account using a Live CD and reset the password in front of me. I was baffled to see such a thing. Please guide me to prevent such a future attempt using a Live CD. How do I turn off equation auto numbering