Hi guys I today started up my pc today(like any other day) and suddenly on desktop my pc freezes completely ctrl+alt+del doesn't work.  So I restarted my pc and suddenly it gave me the bootmgr is missing error, I then unplugged my ext hdd(not that it normally gave me issues) to then get the next issue which is "Reboot and select proper boot device or insert boot media in selected boot device and press a key".  I have no idea where this issue came from, it's all so sudden.   What I did so far is:  Restart it a few times. Check my bios for the boot priority(My SSD is all of a sudden missing) only my disk drive is detectable. Noticed my Bios build is 1107, My motherboard is the Asus P8H67M-Pro, went to the site and saw the latest build 1502 so it's quite outdated although it doesn't reach windows since my ssd is missing so I can't safe start to update my bios.  My SSD is by the way not new, I didn't add anything to my pc external nor internal and my SSD brand is OCZ Vertex 4 120gb. Also I opened up my pc because I read my ssd should be on the sata 0 but I don't see any numbers on the cables for I'm also uncertain which it needs plugged in.  Please help me, thanks in advance.
My computer no longer boots Windows or the installed operating system. Instead, I may get this error:  PXE-E61: Media test failure, check cable -or- Check cable connection!  PXE-M0F: Exiting PXE ROM.   and/or one of the following messages or similar:  Operating System not found  No boot device available- No bootable devices--strike F1 to retry boot, F2 for setup utility  No bootable device -- insert boot disk and press any key  No Boot Device Found. Press any key to reboot the machine  Default Boot Device Missing or Boot Failed  Reboot and Select proper Boot device or Insert Boot Media in selected Boot device   What does this mean and what can I do?     This question comes up often and the answers are usually the same. This post is meant to provide a definitive, canonical answer for this problem. Feel free to edit the answer to add additional details.
How does Newtonian gravitation conflict with special relativity? In the Wikipedia article , it says     After Newtonian gravitation was found to be inconsistent with special relativity, . . .   I don't see how Newtonian gravitation itself is inconsistent with special relativity.  After all, Newton's Universal Law of Gravitation is completley analogous to Coulomb's Law, so it would seem that, if there were an analogous "gravitational magnetic field", one could formulate a theory of gravitation in exact analogy with Maxwell's Theory of Electromagnetism, and of course, this would automatically be consistent with Special Relativity.  What about this approach to gravitation does not work?  The only problem I could see with this is the lack of evidence for a "gravitational magnetic field".  That being said, gravity is "weak" as it is, and my guess is that it would be extremely difficult to set up an experiment in which a massive body were moving fast enough for this "magnetic field effect" to be obsevable.  EDIT:  As has been pointed out to me in the answers, Newton itself is inconsistent with SR.  Similarly, however, so is Coulomb's Law, yet, electromagnetism is still consistent with SR.  Thus, how do we know that it is not the case that Newton's Law is the special "static" case of a more general gravitomagnetic theory exactly analogous to Maxwell's Theory:  Let $\mathbf{G}$ be the gravitation field, let $\rho$ be the mass density, and $\mathbf{J}$ be the mass current density, let $\gamma _0$ be defined so that $\frac{1}{4\pi \gamma _0}=G$, the Universal Gravitation Constant, let $\nu _0$ be defined so that $\frac{1}{\sqrt{\gamma _0\nu _0}}=c$, and suppose there exists a field $\mathbf{M}$, the gravitomagnetic field, so that the following equations hold: $$ \vec{\nabla}\cdot \mathbf{G}=-\frac{\rho}{\gamma _0} $$ $$ \vec{\nabla}\cdot \mathbf{M}=0 $$ $$ \vec{\nabla}\times \mathbf{G}=-\frac{\partial \mathbf{M}}{\partial t} $$ $$ \vec{\nabla}\times \mathbf{M}=\nu _0\mathbf{J}+\gamma _0\nu _0\frac{\partial \mathbf{G}}{\partial t} $$ where theses fields would produce on a mass $m$ moving with velocity $\mathbf{v}$ in our inertial frame the Lorentz force $\mathbf{F}=m\left( \mathbf{G}+\mathbf{v}\times \mathbf{M}\right)$.  This theory would automatically be consistent with SR and would reduce to Newton's Law of Gravitation for the case of gravitostatics:  $\frac{\partial \mathbf{G}}{\partial t}=\frac{\partial \mathbf{M}}{\partial t}=\mathbf{J}=0$.  (To be clear, you can't just set the time derivatives equal to $\mathbf{0}$ as it seems I have done.  Upon doing so, you obtain the corresponding static theory, which is technically incorrect (as you can easily see because it won't be relativistically invariant), but is nevertheless often a useful approximation.)  My question can thus be phrased as:  without appealing directly to GR, what is wrong with this theory? A Russian girl is asking for 500 euros to get a passport in Russia. Is this a realistic amount of money for a passport fee? What happens with lethargy when Haste is cast again on a creature before first cast runs out? Haste states     When the spell ends, the target can't move or take actions until after its next turn, as a wave of lethargy sweeps over it.   However, let's say Character A cast Haste on Character B. In the 10th round (final round of haste if concentration not broken), Character B casts Haste on himself.  What happens during the next round?    Do they lose a round of the "new" haste while they are lethargic and lose movement and actions? Does the new haste override the lethargy until it ends? Is it some combination? Retain AC/Dex modifications but lose actions/movement? None of the above? Simulate bad cell phone reception in the lab Avoiding confusion over the term "Research Assistant" I know that one can use "they" / "them" / "their" in place of "he" / "him" / "his" or "she" / "her" / "hers" when the subject's / direct object's gender is not known; for instance, just looking at the default user's about me section on Stack Exchange sites:     Apparently, this user prefers to keep an air of mystery about them   My question is what happens when someone wants to reference the subject using a pronoun instead.  Should the verb be conjugated accordingly to the pronoun? E.g.:     Apparently, they prefer to keep an air of mystery about them   Or should the conjugation be retained? E.g.:     Apparently, they prefers to keep an air of mystery about them   The former looks unclear because it wouldn't allow the reader / listener to understand if the writer / speaker is talking about a single person or about a group of people, however the latter sounds very weird, at least just to the non-native speaker which I am. How to enable iptables (instead of firewalld) services on RHEL 7 and Fedora 18? The newest fedora has firewalld as new firewall aplication. I liked old iptables services. I want them back but have no idea how to do that. I have tried :  systemctl disable firewalld.service systemctl stop firewalld.service systemctl enable iptables.service systemctl enable ip6tables.service systemctl start iptables.service systemctl start ip6tables.service   But it does not work! Didn't find any help on wiki or google.  Disabling firewalld work ok, but when I'm trying to enable iptables.service I get:  systemctl enable iptables.service Failed to issue method call: No such file or directory Grant admin rights on an application I'm want to grant a user administrative rights to one application on Windows 7. I don't want them to be able to have full admin rights, but admin rights are required for one of the applications they need to use.   Is there a way to set up a batch script or something where the user won't know it's being run as admin?  Or is there another way?  How can I accomplish this? How to print variables without spaces between values How to find an ellipse , given 2 passing points and the tangents at them? Please answer to a question , how to find an ellipse which passes the 2 given points and has the given tangents at them. And one related question is that the given condition can decide just one ellipse which satisfies it?  Thank you in advance.  Edit : May be , I can say the first answer (by Mr. André Nicolas) is for the general case. Is there no special case where only a finite set of ellipses satisfies the condition?  Edit : According to the answers and comments , I can compute an arbitrary chosen ellipse for my condition (using the method by Mr.Patrick Da Silva). But there are possibly many others which satisfy my conditions. Am I right? 'Some index files failed to download' while updating When running sudo apt-get update I get these following errors:  Err archive.ubuntu.com quantal InRelease Err archive.ubuntu.com quantal-updates InRelease Err archive.ubuntu.com quantal-backports InRelease Err archive.ubuntu.com quantal-security InRelease Err archive.ubuntu.com quantal Release.gpg   Unable to connect to archive.ubuntu.com:http: [IP: 91.189.92.177 80] Err archive.ubuntu.com quantal-updates Release.gpg   Unable to connect to archive.ubuntu.com:http: [IP: 91.189.92.177 80] Err archive.ubuntu.com quantal-backports Release.gpg   Unable to connect to archive.ubuntu.com:http: [IP: 91.189.92.177 80] Err archive.ubuntu.com quantal-security Release.gpg   Unable to connect to archive.ubuntu.com:http: [IP: 91.189.92.177 80] Reading package lists... Done W: Failed to fetch archive.ubuntu.com/ubuntu/dists/quantal/InRelease   W: Failed to fetch archive.ubuntu.com/ubuntu/dists/quantal-updates/InRelease   W: Failed to fetch archive.ubuntu.com/ubuntu/dists/quantal-backports/InRelease   W: Failed to fetch archive.ubuntu.com/ubuntu/dists/quantal-security/InRelease   W: Failed to fetch archive.ubuntu.com/ubuntu/dists/quantal/Release.gpg  Unable to connect to archive.ubuntu.com:http: [IP: 91.189.92.177 80] W: Failed to fetch archive.ubuntu.com/ubuntu/dists/quantal-updates/Release.gpg  Unable to connect to archive.ubuntu.com:http: [IP: 91.189.92.177 80] W: Failed to fetch archive.ubuntu.com/ubuntu/dists/quantal-backports/Release.gpg  Unable to connect to archive.ubuntu.com:http: [IP: 91.189.92.177 80] W: Failed to fetch archive.ubuntu.com/ubuntu/dists/quantal-security/Release.gpg  Unable to connect to archive.ubuntu.com:http: [IP: 91.189.92.177 80] W: Some index files failed to download. They have been ignored, or old ones used instead.   I am using Ubuntu 12.04. This is the command I used after installing Ubuntu from window installer. I am sure my laptop is connected to internet. What can I do now? On November 11, my American girlfriend flew over to the UK to visit me. She was detained and questioned, and refused entry under the belief she would not leave within those six months. This was due to her having no return flight booked, as we were going to wait until we were together in the UK to book a return flight for either herself, or both of us back to the USA once we decided what exact dates I would be able to travel. Lesson learned. A hard lesson, but we learned!  Anyway, they said although she'll flag up in the future, it won't be a straight ban from entering and she could even try to come back the next day if she so pleased, although it would be unwise if her circumstances had not changed.  Fast forward to December 18. She got herself a job in the States to prove she intends to leave at the end of her stay, and has since applied for a UK Standard Visitor Visa. She posted her documents off to New York earlier today.  Will they send her a letter back refusing to issue her a visa since, as an American citizen, she does not even need one? She wanted to get one to be safe as I told her not to fly to the UK even with return flights booked if she doesn't have a visa, as she risks being denied once again after a long flight. It's hard to get this information on the Internet, and some stories I read said that they were sent a letter back from the UK Embassy denying their visa simply because they don't need one in the first place - even after that person was denied entry.  We're in a bit of a pickle granted, so any help would be greatly appreciated.   Cheers. Where should I post my sum-up of the answers, as the OP? How to AutoSize the height of a Label but not the width Union of a finite set and a countably infinite set is countably infinite Okay, obviously beyond Data and the Soong-type androids. But seriously, we have more robots in our daily life now than there apparently are on Trek. Is there a canon answer why not? It seems like Star Wars is more on the nose in this regard - it’s unclear why all dirty/dangerous/boring work wouldn’t be done by robots (anthropomorphic or not). Smoothness constraint of wave function Is there anything in the physics that enforces the wave function to be $C^2$? Are weak solutions to the Schroedinger equation physical? I am reading the beginning chapters of Griffiths and he doesn't mention anything. I recently moved from having a main site like www.example.com with a subdomain associated site yyy.example.com, to moving everything off the subdomain to a subdirectory like www.example.com/yyy/, with the same hierarchy underneath the subdirectory, and now yyy.example.com is just a redirect page to the subdirectory, so yyy.example.com/abc/page-x is redirected to www.example.com/yyy/abc/page-x and so on.  The effect has been that the traffic increased by several times (the total page views are more than ten times at the present rate) what it was to the yyy subdomain. Previously almost all of the traffic to the yyy subdomain was from the www site. This is from monitoring the old yyy site for a year or more.  I'm curious to know if there's any research or results which would indicate whether this is universal (subdirectories beat subdomains) or "just me". If $(1), (log_yx), (log_zy), (-15log_xz)$ are in Arithmetic Progression... If $(1), (log_yx), (log_zy), (-15log_xz)$ are in AP then...   (A)$z^3=x$   (B)$x=y^{-1}$   (C)$z^{-3}=y$   (D)$x=y^{-1}=z^3$   (Multiple answers may be correct)   I tried many approaches, one of them being: $1+log_zy=2log_yx$ $log_zz+log_zy=log_yx^2$ $log_z(yz)=log_yx^2$ But the fact that the bases are different is causing the main problem as I don't know how to proceed further. It would be great if anybody could give me a hint for solving such questions. How to find out when an Oracle table was updated the last time Can I find out when the last INSERT, UPDATE or DELETE statement was performed on a table in an Oracle database and if so, how?  A little background: The Oracle version is 10g. I have a batch application that runs regularly, reads data from a single Oracle table and writes it into a file. I would like to skip this if the data hasn't changed since the last time the job ran.  The application is written in C++ and communicates with Oracle via OCI. It logs into Oracle with a "normal" user, so I can't use any special admin stuff.  Edit: Okay, "Special Admin Stuff" wasn't exactly a good description. What I mean is: I can't do anything besides SELECTing from tables and calling stored procedures. Changing anything about the database itself (like adding triggers), is sadly not an option if want to get it done before 2010.