Is mass slowly destroyed when force of gravity is applied?
Where does tidal energy come from?
Looking for title & author - short story - possibly called "Arms Race" - about rediscovery of manual arithmetic short story - possibly called "Arms Race" - about rediscovery of manual arithmetic.   The hero rediscovers manual calculation - e.g., how to do long division with pencil and paper - in a world where everyone has ben using calculators for aeons. Brought before the president to demonstrate this, the great line in the story is the president, after using his calculator to check the hero's answer, says, "My God -- he's right." A great national project to exploit this advance over the enemy is obviously necessary... I see stuff like command 1&gt; out or with 2&gt;&amp;1 to redirect stderr, but sometimes I also see &amp;&gt; by itself, etc.  What is the best way to understand &amp; and what it means exactly? How can tangential acceleration from a radial force be explained? Emmy Noether's theorem in simpler terms I'd like to understand  and its contents as to what it implies in a bit simpler terms. I am familiar with mathematics unto Calculus 1,2,3 and some linear algebra and group theory. I am familiar with that for each symmetry there is a conservation law.    Now is there a one-one correspondence between these two always? What about laws like conservation of charge?  And conservation of energy?  And conservation of mass?  Considering our view of nature was changed as Special Relativity was introduced and thus, what earlier the theorem would have asserted as mass and energy to be originating from different symmetries then how did we reconcile these two as just one symmetry? Drawing text and line-dasharray Is it possible with TileMills and CartoCSS? What is the reason Men play 5 sets & Women play 3 sets in a Grand Slam in Tennis? In the ATP &amp; WTA events, both Men &amp; Women tennis players play best of 3 sets. But when it comes to Grand Slams, the Men play 5 sets. At the risk of sounding a misogynist, I always believe the reason to be strength &amp; endurance. After all, a 5 set EPIC match lasts 5 hours while a 3 set EPIC last 3 hours.    Is that the only reason. Or am I a naive misogynist? Also was that the case since the history of Grand Slams or did Men play 3 sets before? Case insensitive 'Contains(string)' Is there any (even the most subtle) difference between the meaning (or connotation) of that is and i.e.?  I used to be convinced that they were synonyms, until an editor of a scientific journal changed all occurrences of i.e. into that is. While I'm aware of  it does not quite answer my question. I have a simple sentence:     If any of the devices was not switched off, do something.   Is there supposed to be was or were? I was thinking about was since it could be rephrased as:     If any one of the devices was not switched off, do something.   But maybe that does not make any sense at all. Also, this is for a technical documentation where more formal language is preferred, not sure if that makes any difference. Two "if"s in a row How can I create a product key for my C# application? How can I create a product key for my C# Application? I need to create a product (or license) key that I update annually.  Additionally I need to create one for trial versions.  Related: URLs: Should I use hyphens, underscores or plus symbols? Which is better for search engines?   example.com/my_cool_page.html example.com/my-cool-page.html  example.com/my+cool+page.html Privacy leak in permalink? Update (Jan 8, 2019) This is now 8 years old, but still getting occasional upvotes/attention, so I thought it's worth giving a summary of the current state.  Despite originally being , over the last decade some changes have made the privacy implications much clearer.  You now click &quot;share&quot; instead of &quot;link&quot;, and the pop-up is very explicit that the link includes your user ID. There is a  asking that this user ID be anonymized or hashed, to allow users to earn publicity badges (the intention behind having the user ID present in the URL, as per ) while eliminating the privacy issue. Original Post It seems to me there is something of a privacy leak when permalinking to a question.  For what I would assume is the purposes of tracking which user is responsible for bringing traffic back to an SE site (for badges, etc.), the user ID of the user obtaining the permanent link . I wouldn't argue that this shouldn't be the case, but I find no warning or mention of this when I do these actions.  I'm sure I'm not the only one that doesn't desire anonymity on SO but would like at least pseudonymity on some places I might share a SO link, such as on a random blog.  As a user, I would not expect sharing a permanent link to leak my identity.   Unless you are familiar with Stack Exchange links or your own userID, it's certainly not obvious by looking at the link that it includes your personal info.  It'd be nice to have fair warning that using that feature will do so, and perhaps provide/describe the workaround: to simply remove the user-id segment from the URL.  Other features would be a preference that formats future permanent links to exclude the user id. Example (from this question)  Permalink:  Link to my user page: Why does chmod 777 -R / leave the system unusable? I'm only granting permission to all to do anything but why does the system crash by giving permissions only? I'm only modifying the permission not changing the files. Prove $[0, 1]$ and $(0, 1]$ are equinumerous by use of bijection What my thought was that the bijection was a piecewise function:  $f(x) = 1/n+1$ if $x = 1/n$ for some $n \in \Bbb N$ and $x=1/n$ if $x \neq1/n$ for some $n \in \Bbb N$.  However, the textbook says this is incorrect. I don't actually see why. Was it a matter of brackets or the open variable $(0,1]$, which is what I tend to think. Suspended user cannot award bounty When asking a new question and typing in the title we get a list of similar questions named     Questions that may already have your answer     That suggestions contains posts across all tags. Like the example in the screenshot it returns similar questions for Python, jQuery, SQL, C#, Java, C++, ...  This makes the list less useless unlikely people find a question that already answers theirs. If people actually find a similar question in that list many duplicates could be avoided.  So can tags I entered below the question be considered to update the list? And can the tag textbox maybe put above the question title? In Iron Man 3,      When the real villain kidnapped the President of the United States,   it is never explained why none of the other Avengers came to help, or why Tony didn't call them. The only explanation so far is: "it was an Iron Man movie...", but an in universe answer would be good. Including Interaction Terms in Random Forest Suppose we have a response Y and predictors X1,....,Xn. If we were to try to fit Y via a linear model of X1,....,Xn, and it just so happened that the true relationship between Y and X1,...,Xn wasn't linear, we might be able to fix the model by transforming the X's somehow and then fitting the model. Moreover, if it just so happened that the X1,...,XN didn't affect y independent of the other features, we also might be able to improve the model by including interaction terms, x1*x3 or x1*x4*x7 or something of the like. So in the linear case, interaction terms might bring value by fixing non-linearity or independence violations between the response and the features.  However, Random Forests don't really make these assumptions. Is including interaction terms important when fitting a Random Forest? Or will just including the individual terms and choosing appropriate parameters allow Random Forests to capture these relationships? Pros and cons of rooting using apps ("Soft Root") compared to other methods ("Hard Root") There are quite a few app based rooting methods. A recent review , points to some of them and there may be more apps, paid or otherwise.  From what I understand,   Plus Points   Ease of rooting Don't need a laptop or computer   Minuses   Based on exploits, so may not work if exploits are denied by OS updates Difficulty in unrooting (as I see on some forums for my device Huawei Honor 6)   Questions:    What are the pros and cons apart from above?  If a device has both options - app based rooting and rooting by methods by developers, which one should I opt for?   Note: I am not seeking app suggestion or recommendation.