How many network switches can I daisy chain together
How many switches can be stacked/interconnected?
What equipment should I have to kill the Eye of Cthulhu? I just manually summoned the Eye of Cthulhu, going into battle with copper armour, tungsten broadsword, gold bow, jester arrows and plenty of lesser healing potions. I came rather close to death but I managed to stay alive. However, the Eye took off when I had his health down to ~1700. I'm assuming this means you only have a few minutes to finish it off after a certain point. Is there any equipment I'm missing to help kill the Eye faster and to help my survivability? If it's relevant, my current life is 120. I am constructing a thought experiment about a spinning object that is floating in intergalactic space.  I assume that this object is about the size of a planet so that it will have enough gravity so that a Foucault pendulum will work, although I'm not sure that this is necessary for the thought experiment.    I can easily determine that this object is spinning if I stand on the object and observe the galaxies around me rise and set.  Similarly, I can determine the axis of rotation.    For simplicity, I go to one of the poles of my object, and I set up my Foucault pendulum.  What will I see?  And why will I see it?  I assume that in intergalactic space, the gravity is very small (galaxies are very far away, and the mass of my object is very small compared to the mass of a galaxy) so that there will be little coupling between the gravitational field of my object and the gravitational field of the galaxies around me. In the Deadpool movie when Wade his mutant cells get activated, his skin changes so he looks like Freddy Krueger (As Weasel referred too). But he obtains healing abilities and his cancer gets cured because of it. He's become an immortal person which can heal any wound super fast.  What I don't understand is, why doesn't his skin heal so he would look like before? I remember that Francis (or Ajax) said that it's a 'side-effect' of mutating, but why wouldn't it heal when he has a healing ability? Why is df missing 500MB of available space? I've just had a message today from Ubuntu 11.04 that I have only 100 MB left, so I cleaned up some files, and I got 200 MB. Then, after a couple of hours, suddenly I have only 26 MB?! I tried df, du via mount --bind, /forcefsck with reboot - nothing could should what the culprit is - finally I searched big files, realized /var/log/syslog is 100MB+ and /var/log/kern.log is 200MB+ - blanked them with sudo bash -c 'echo &gt; ...' and rebooted, and now I have some spare MB.  But now, I realize I have another problem with df:  $ df -h Filesystem            Size  Used Avail Use% Mounted on /dev/sda5             9,7G  8,8G  385M  96% / none                  963M  696K  962M   1% /dev none                  969M   12K  969M   1% /dev/shm none                  969M  252K  969M   1% /var/run none                  969M     0  969M   0% /var/lock /dev/sda6             9,7G  8,1G  1,1G  89% /media/disk  $ df -h --block-size M Filesystem           1M-blocks      Used Available Use% Mounted on /dev/sda5                9845M     8960M      385M  96% / none                      963M        1M      962M   1% /dev none                      969M        1M      969M   1% /dev/shm none                      969M        1M      969M   1% /var/run none                      969M        0M      969M   0% /var/lock /dev/sda6                9845M     8235M     1110M  89% /media/disk   Note so for /, it says there are 9845M total; and Used 8960M - then remaining would be 9845-8960 = 885 M, however, here I have only 385M Available.  Also, for /media/disk, it says total 9845M, Used 8235M - then remaining would be 9845-8235 = 1610, however, here I have only 1110M Available.  In both cases, there is exactly 500 MB difference.  Where did this difference come from - and can I reclaim it?  Here is also lsof | grep 'deleted' - can't see nothing suspicious here:  $ lsof | grep 'deleted' nautilus  1911 user   21u      REG        8,5   142760     260562 /home/user/.local/share/gvfs-metadata/home (deleted) nautilus  1911 user   22w      REG        8,5    32768     268807 /home/user/.local/share/gvfs-metadata/home-fe882154.log (deleted) python    1919 user    8u      REG        8,5     4096     392258 /tmp/ffiqRK968 (deleted) python    2165 user    5w      REG        8,5        0     132261 /home/user/.[SNIP].lock (deleted) python    2166 user    5w      REG        8,5        0     132261 /home/user/.[SNIP].lock (deleted) python    2185 user   21r      REG        8,5   142760     260562 /home/user/.local/share/gvfs-metadata/home (deleted) python    2185 user   22r      REG        8,5    32768     268807 /home/user/.local/share/gvfs-metadata/home-fe882154.log (deleted) gnome-ter 2279 user   27u      REG        8,5      640     392575 /tmp/vte5KDX2X (deleted) gnome-ter 2279 user   28u      REG        8,5     4936     392605 /tmp/vteKRDX2X (deleted) gnome-ter 2279 user   29u      REG        8,5      648     392947 /tmp/vteMZDX2X (deleted) ubuntuone 2544 user   17u      REG        8,5     4096     392335 /tmp/ffiMErq0V (deleted) bamfdaemo 3235 user   12r      REG        8,5   143868     269077 /home/user/.local/share/gvfs-metadata/root (deleted) bamfdaemo 3235 user   13r      REG        8,5    32768     272310 /home/user/.local/share/gvfs-metadata/root-18092a02.log (deleted) firefox   5291 user   59u      REG        8,5    33288     132262 /var/tmp/etilqs_YdeZiWSd5iQwJ4U (deleted) firefox   5291 user   60w      REG        8,5    32768     132271 /var/tmp/etilqs_MNLXhEaEqoXMm9b (deleted) firefox   5291 user   70u      REG        8,5    34952     132297 /var/tmp/etilqs_yXDdwVeMxmmdpNz (deleted) How many combinations of groups are there where no member of a group has been with another member before? I found this hard to word in the title, so let me give an example. I have 16 students, and I want to split them up into 4 groups of 4. However, I want to make sure that every time I have a new combination of groups, that a student has never been with any of their new groupmates before. I found info on how to separate objects into groups, but not in only unique ways as I've described above. I think I figured this out the rote way, by assigning each student a number and then finding the unique combinations, and got 3. But I'd like to know the math behind it, and how it could be applied to other configurations (20 students w/ 4 groups of 5?). Thanks for any help you can give! Adding a reference between Eclipse Java projects Why does the following hold:  \begin{equation*} \displaystyle \sum\limits_{n=0}^{\infty} 0.7^n=\frac{1}{1-0.7} = 10/3\quad ? \end{equation*}  Can we generalize the above to      $\displaystyle \sum_{n=0}^{\infty} x^n = \frac{1}{1-x}$ ?   Are there some values of $x$ for which the above formula is invalid?  What about if we take only a finite number of terms? Is there a simpler formula?     $\displaystyle \sum_{n=0}^{N} x^n$   Is there a name for such a sequence?    This is being repurposed in an effort to cut down on duplicates, see here: Coping with  duplicate questions.  and here: . "The following packages have been kept back:" Why and how do I solve it? I just added a PPA repository for the development version of the GIMP, but I get this error:  $ apt-get update &amp;&amp; apt-get upgrade ... The following packages have been kept back:   gimp gimp-data libgegl-0.0-0 libgimp2.0   Why and how can I solve it so that I can use the latest version instead of the one I have now? I've just begun to work learn Linear Algebra on my own through Hoffman and Kunze's book and the first problem set already has a question that I can't solve:  Prove that if two homogeneous systems of linear equations in two unknowns have the same solutions, then they are equivalent.  I can't seem to figure out how to prove this without resorting to case work where you account for the cases where one of the coefficients are zero and when both are.  Is there an elegant way to prove in general that when two systems of linear equations have the same solutions, they are equivalent? The converse is obvious enough though.  Definition of equivalence from the text :     Let us say that two systems of linear equations are equivalent if each equation in each system is a linear combination of the equations   in the other system. The company I work for makes hardware that communicates to the computer though a serial port. Third party companies write software that communicates with our hardware.   There are times when I need to diagnose our hardware. However, a third party software app connects to the serial port when Windows starts up, blocking any other connection. I don't know the name of this application/service and it's not always the same one.  Is there any way to either:   Find the name/pid of the app/service that is currently using a given serial port or Steal the serial port connection from another app.   vb.net preferably, but I'll take a language agnostic answer as well. This is Exercise 3.1.A. in      Suppose that $\pi: X\rightarrow Y$ is a continuous map of differentiable manifolds. Show that $\pi$ is differentiable if differentialble functions pull back to differentiable functions, i.e., if pullback by $\pi$ gives mpa $\mathcal{O}_Y\rightarrow \pi_*\mathcal{O}_X$.   Let $f: V\subseteq Y\rightarrow \mathbb{R}$ be a differentiable function on an open subset of $Y$. Let $(U,\phi)$ be a chart of $X$, $(V,\psi)$ be a chart of $Y$. Then $f\circ\pi(\phi^{-1})$ is differentiable and $f\circ\psi^{-1}$ is differentiable. We need to show that $\psi\circ\pi\circ\phi^{-1}$ is differentiable. I don't know how to prove this.   Can we say that since $(U,\psi\circ\pi)$ constructs a chart of $X$, by the compatibility, $\psi\circ\pi\circ\phi^{-1}$ is differentiable? This seems true but this does not use the fact that $f$ is differentiable.  Sorry I have no background of Differentiable Manifolds. Any help would be appreciated.  I also saw this post: , but I don't understand how $\gamma$ is smooth in the answer. $\gamma=\beta\circ\rho$, where $\rho$ is defined to be smooth, but $\beta$ is not. How do I get an operating system onto a new hard drive? Search engines and browser accept-language I'm building a web portal where language content will generally depend on the "accept-language" sent by the browser. The same content-URI will thus serve different content to different users depending on their browser setting.  I'm very curious to know how this will affect search indexing. Does Google index using all languages, and is it handled well? How to change/rewrite the lost password url? I used iThemes Security (formerly Better WP Security) hide back-end functionality to change the login url to /signin however clicking the lost password link /wp-login.php?action=lostpassword now generate a 404  Manually going to /signin?action=lostpassword works.  I came across the following code below which is suppose to make the change to however after some testing it doesn't seem to work  //******************************************************* //Function to change to lost password url //******************************************************** add_filter('site_url',  'wplogin_filter', 10, 3); function wplogin_filter( $url, $path, $orig_scheme ){     $old  = array( "/(wp-login\.php)/");     $new  = array( "signin/"); //this can be change to login or whatever or may remain there     return preg_replace( $old, $new, $url, 1); }   add to .htaccess  RewriteRule ^signin$ wp-login.php   How can i modify the above code in order to change the url for the lost password? Proof of Heron's Formula for the area of a triangle Let $a,b,c$ be the lengths of the sides of a triangle. The area is given by Heron's formula: $$A = \sqrt{p(p-a)(p-b)(p-c)},$$ where $p$ is half the perimeter, or $p=\frac{a+b+c}{2}$.  Could you please provide the proof of this formula? Thank you in advance. Is the intersection of a closed set and a compact set always compact? Use of "save" or "save for" in sentences I set up Windows 10 and have been using it for months on a spare laptop.  When installing, I did not use a Microsoft account to enable all of the app connectivity because I don't need that functionality.  I do not want these features active on this device, and I used a simple user name during the install.  Everything was going fine until I read about the Linux/bash features that are available in the anniversary update.  I decided to try them out and entered my Microsoft Insider credentials to enable the features in the developer options of the Control Panel.  I didn't realize the primary account on this device would now become linked to that Microsoft account.  Is there a simple way to disassociate the Microsoft account from the local account, or are they now linked forever in an unholy union?  I can set up a new local account, but I'd rather not lose all the settings and folder preferences prior to my gaffe. When I was younger (11-12 years old, so the early 2000s) I once read a story where a young boy, who may have been either a young prince or a squire of some sort, is recruited by a wizard and taken to a city to train as a mage.  I seem to remember him living in dorms with the other children at this school, until he gets into difficulty with another of the boys in the dorm. He is kicked out of the dorms and ends up living above a blacksmith shop (I think).  I remember it being the first book in a series of books of which there were about 3 out at the time. I think one of the stories was about the boy going to a tower to do something or other.  Does anyone have any idea what this book series is? I haven't been able to find it for years now but it was a story I really loved. I have two sites that were originally migrated from SPS2003.  It worked well in SharePoint 2007 and even on SharePoint 2010,  however when we migrated it to SharePoint 2013,  the home page throws following errors on the ULS Log.     5/24/2013 09:57:46.62  w3wp.exe (0x0D50)   0x1D24  SharePoint Foundation   Files   ak8dj   High   UserAgent not available, file operations may not be optimized.    at Microsoft.SharePoint.SPFileStreamManager.CreateCobaltStreamContainer(SPFileStreamStore spfs, ILockBytes ilb, Boolean copyOnFirstWrite, Boolean disposeIlb)     at Microsoft.SharePoint.SPFileStreamManager.SetInputLockBytes(SPFileInfo&amp; fileInfo, SqlSession session, PrefetchResult prefetchResult)        05/24/2013 09:57:46.62 w3wp.exe (0x0D50)   0x1D24  SharePoint Foundation   Cobalt  ajoii   Medium   Mapping Store error to Cobalt error. [Store Error: System.NullReferenceException: Object reference not set to an instance of an object.     at Microsoft.SharePoint.CoordinatedStreamBuffer.SPCoordinatedStreamBufferFactory.CreateFromDocParams(SqlSession session, Guid guidSiteId, Int32 cbContent, Nullable1 parentId, Guid docId, Nullable1 level, SPChunkedArray`1 rgbContent, Byte[] rgbRbsId, Int64 bsn, Byte partition, Int32 pageSize, Boolean bStartFilling)        05/24/2013 09:57:46.62 w3wp.exe (0x0D50)   0x1D24  SharePoint Foundation   Cobalt  aintx   High    Failed in CobaltStream.LockBytes: ErrorException --- Error: Unknown (Win32=0x80004003) --- Error message: System.NullReferenceException: Object reference not set to an instance of an object.     at Microsoft.SharePoint.CoordinatedStreamBuffer.SPCoordinatedStreamBufferFactory.CreateFromDocParams(SqlSession session, Guid guidSiteId, Int32 cbContent, Nullable1 parentId, Guid docId, Nullable1 level, SPChunkedArray`1 rgbContent, Byte[] rgbRbsId, Int64 bsn, Byte partition, Int32 pageSize, Boolean bStartFilling)     at         05/24/2013 09:57:46.64 w3wp.exe (0x0D50)   0x1D24  SharePoint Foundation   Files   ak8dj   High    UserAgent not available, file operations may not be optimized.    at Microsoft.SharePoint.SPFileStreamManager.CreateCobaltStreamContainer(SPFileStreamStore spfs, ILockBytes ilb, Boolean copyOnFirstWrite, Boolean disposeIlb)     at Microsoft.SharePoint.SPFileStreamManager.SetInputLockBytes(SPFileInfo&amp; fileInfo, SqlSession session, PrefetchResult prefetchResult)     at         05/24/2013 09:57:46.64 w3wp.exe (0x0D50)   0x1D24  SharePoint Foundation   Database    ab1a9   High    Failed to get document content data. System.NullReferenceException: Object reference not set to an instance of an object.     at Microsoft.SharePoint.CoordinatedStreamBuffer.SPCoordinatedStreamBufferFactory.CreateFromDocParams(SqlSession session, Guid guidSiteId, Int32 cbContent, Nullable1 parentId, Guid docId, Nullable1 level, SPChunkedArray`1 rgbContent, Byte[] rgbRbsId, Int64 bsn, Byte partition, Int32 pageSize, Boolean bStartFilling)     at   I could not find any materials related to this on the internet,  I am not even sure if it has to do something with SPS2003 compatibility.  Any help pointers?