I have bought a stainless steel pot steaming insert. Will adding salt to food (maybe frozen) when I start cooking it with steam cause pitting of the insert? Thank you.
In the context of boiling water for pasta or other purposes, all over the Internet the advise is oft-repeated that salt should not be added to the water when it is cold in order to prevent damage to the pot such as pitting over long term use.  The reasoning is that the salt stays on the bottom of the pot for longer without dissolving, and has a chance to interact with the surface metal.  Is there any objective evidence--preferably scientifically based--that this phenomenon actually occurs in practical kitchen-type conditions, or is this another piece of common wisdom that is often shared but not backed by evidence, much like  common wisdom that it is necessary to use very large volumes of water to cook pasta?
Where should collision detection logic be placed? I am developing a small 2D game engine. The characters have a paint method which currently does the following:   Calculate the new position of the character as per its speed, etc. Update the collision grid cell ** Draw the character at the new position   ** I have created a collision grid to reduce the number of intersection checks  Now the basic algorithm which I have thought for detecting collision is:   For Each Character     Check intersection with characters in surrounding 8 cells   I can simply place this code in the paint method. But here is the problem I anticipate.  Suppose two characters A and B lie in adjacent cells in the collision grid. Now as per the above algorithm in the iteration of character A it will detect that it has collided with B. In the iteration for character B it will detect that it has collided with A.  But I have an idea that when A detects that it has collided with B, it should inform B that it has collided with A. This would save lot of comparisons when there are more than 2 actors colliding. But I am not sure how to handle this. I think instead of every character checking for its collision, I should check for the collision inside the game loop.   Would this approach be correct? How have you handled this kind of problem? I thought of the collision grid thing myself. Are there any alternatives to collision grid logic? For $a, b \geq 0$, $0 < x < 1$, show $(a+b)^x \leq a^x + b^x$ Let $a, b$ be positive real numbers. Let $0 &lt; x &lt; 1$. Show that  $(a+b)^x &lt; a^x + b^x$.  The function $f(x) = (a+b)^x -a^x - b^x$ has $f(0) = -1$, $f(1) = 0$ and it seems to be an increasing function. But I am unable to show that it is increasing function. $\|h(x)-h(y)\|\geq 3\|x-y\|$ prove that image of open is open Why does the multi-paragraph quotation rule exist? How do exchanges match limit orders? Let $A$ be a square matrix of order $n$ such that $A^2 = I$.  Prove that if $1$ is the only eigenvalue of $A$, then $A = I$. Prove that $A$ is diagonalizable.   For  (1), I know that there are two eigenvalues which are $1$ and $-1$, how do I go about proving what the question asks me? When I create a UV sphere and add the subdivision surface modifier, the following wrinkle appears.    How can I avoid it?  I've read the article  but there seems to be no clear solution.  UPDATE 1  I've used the word 'apply' in the first sentence of the initial version of this question. It's misleading since I want to preserve the modifier without 'applying' it. Rather, what I meant is 'adding' the modifier.  UPDATE 2  I followed josh sanfelici's solution, but still there is an artifact at the pole.  Here is the screen: (A rendered view with a sun lamp)    Maybe it's the limitation of the general-purpose subdivision modifier.  BTW, when the cast modifier is added after the subdivision modifier, the sphere becomes perfect (even for my original wrinkled sphere).  But since I want to edit the resulting sphere (for example, scaling X, Y, etc) while modifier is added but not applied, it's not usable. Look at this if block:  #!/bin/bash  str="m.m" if [[ "${str}" =~ "m\.m" ]]; then     echo "matched" else     echo "not matched"     exit 1 fi  exit 0   This should print "matched", but it doesn't. Where am I going wrong? Is convex surface normal in cast iron skillet? I am new to cast iron skillet. I have cooked with it several times and found the Lodge 12" cast iron skillet has a convex surface which is not observable unless you pour oil on it.  When I cook, the oil move to rim of the skillet and makes the center short of oil. Is it normal?  EDIT: I added the photo of the stove and skillet for reference Adding Basemaps from Google or Bing in QGIS ArcGIS Desktop has the option of using basemaps from ArcGIS Online. Does QGIS have any such options? How many ancestors alive 1000 years ago does a person have on average? I was thinking about something the other day (that is probably stupid), and thought this would be a good place to talk about it.  If someone wanted to draw its family tree over the last 1000 years, he'd write a binary tree with a depth of about 40 (counting 25 years on average between each generations). This tree would have 240 leaves, or about 1012 ancestors on the deeper level. That is obviously much more than the total world population and a stupid figure when you think about it.  The only explanation that I can think of is that a real genealogy tree must have "linked" branches at several levels that change the actual number of ancestors. Anyway, for an average person, how many ancestors would that make? Could one assume that all or nearly all of the persons that lived in its country or world region a 1000 years ago would be part of its ancestors? $G$ is non abelian simple group of order $<100$ then $G\cong A_5$ Trouble doing polynomial interpolation Notify us when the question has been edited after posting an answer I was answering a question on Stack Overflow and required to use a trailing space in one of my code snippets.  I formatted it like so:  `&lt;a `   And it renders without the trailing space: &lt;a  Using the &lt;code&gt; tag does account for trailing spaces, though in my case it busts because of the &lt;. Here's my formatting with the &lt;code&gt; tag:  &lt;code&gt;&lt;a &lt;/code&gt;   Here's how it renders:  (Yes, you should see nothing there).  This is a pretty annoying bug. Can we get it fixed? How can an int be cast to an enum in C#? How does the new automatic reference counting mechanism work? Cannot boot because: Kernel panic - not syncing: Attempted to kill init! This is what I've got. I cannot boot and I see the two of three little lights on the keyboard blinking all the time and the cooling is working on full power, almost.  I saw in other askubuntu topic suggestion for memory test. I did it. I didn't have any errors.  I am 99,9% sure it is not a hardware problem, because I have Windows 7 and I can boot it and it works just fine.  This problem came without any warning or something. I just turned off the laptop one day and at the other day I couldn't boot.   From recovery mode I get this: Let $(M,d)$ be a metric space, and $A\subset M$. By definition, $A$ is said to be compact if every open cover of $A$ contains a finite subcover.  What is wrong with saying that, in $\mathbb{R}$, if $I=(0,1)$, we can choose $G=\{(0,\frac{3}{4}), (\frac{1}{4}, 1)\}$, which satisfies $I \subset \bigcup_{U\in G} U$, but we can't extract a finite subcover, so $I$ is not compact. Is $G$ a finite subcover of $G$, so it is not a valid cover for proving this? I would take $\cup_{n\in\mathbb{N}} (\frac{1}{n},1)$ in order to prove this, can we conclude that every open cover is necessarily a infinite union of open sets $\neq \emptyset$? On the three Stack Overflow chat servers, the  page displays the following image:    Is it from an actual episode, or is it a 'shop?