Between Hawking &amp; Ellis and Wald, which one would be the better choice to follow up a graduate-level course in GR (based off of Carroll's book)?  If not either of those two, does anyone have any suggestions? I'm interested in those two not only because of the physics they present but also because of their rigor (I'm a post-grad mathematician).
What are some good books for learning general relativity?
Why does the max aperture change when use Nikon 60mm AF-D Micro on D90 camera? I have found that my Nikon 60mm Micro AF-D changes aperture from 2.8 to 3.2 when used with a D90. I have tried both A and M mode. Is it by design? Why?  I intend to buy  and it will lock the maximum aperture at 2.0 (my guess) instead 2.8. So should I buy it or not, or would it be better to buy the newer 50mm 1.4 AF-S version? How to get rights of admin after I disabled all admin accounts in my computer What is this Disney scifi movie from the late 80s/early 90s? Is “what’s” a correct short form of “what does”? E.g. “What’s he think?”  Usually ’s is short for “is” so I don’t know. Database does not update automatically with MySQL and Python I'm having some trouble updating a row in a MySQL database. Here is the code I'm trying to run:  import MySQLdb  conn=MySQLdb.connect(host="localhost", user="root", passwd="pass", db="dbname") cursor=conn.cursor()  cursor.execute("UPDATE compinfo SET Co_num=4 WHERE ID=100") cursor.execute("SELECT Co_num FROM compinfo WHERE ID=100") results = cursor.fetchall()  for row in results:     print row[0]  print "Number of rows updated: %d" % cursor.rowcount  cursor.close() conn.close()   The output I get when I run this program is:     4Number of rows updated: 1   It seems like it's working but if I query the database from the MySQL command line interface (CLI) I find that it was not updated at all. However, if from the CLI I enter UPDATE compinfo SET Co_num=4 WHERE ID=100; the database is updated as expected.  What is my problem? I'm running Python 2.5.2 with MySQL 5.1.30 on a Windows box. Why does my regular expression work in X but not in Y? Why can Naruto still use Rasenshuriken? When Naruto first used Rasenshuriken against Kakuzu the effect was massive. He destroyed   two of Kakuzu's hearts, but there were a huge after effect to him. If I'm not mistaken, Tsunade advised Kakashi to ask Naruto never to use the technique again due to the huge risk. So why is Naruto still able to use the technique and have no side effects after that battle? I may have missed out on something. How can I add a second hard drive to a previously configured UEFI/ACHI Windows 8 machine? Recently purchased a new Windows 8 PC.  It came with one hard drive.  I want to a second hard drive to it.  This second hard drive is my data hard drive from my previous computer.  However, I have run into issues when the system accesses it.  The drive is found in the BIOS. But is not seen by Explorer or Disk Management.  I have added the drive to the next available SATA slot:  SATA 2.  The machine is a UEFI/ACHI based machine.  In my reading I have found people documenting the following:  1) adding multiple partitioned hard drives (like mine is) to UEFI based machines is not  possible 2) I have seen it suggested that you can only add blank hard drives to UEFI based machines.  However, in doing so, I did not have success.  I tried to add it as a hard drive with unallocated space and then as a hard drive with a single simple partition.  Both attempts failed.  My ultimate question:  What is the proper procedure for adding a second hard drive to a UEFI/ACHI machine?  I do not want to reinstall the OS and start from scratch as I have seen suggested elsewhere.  There has to be a way to accomplish this without all that hassle.  Thanks in advance for your help. Does this polynomial evaluate to prime number whenever $x$ is a natural number? I can't find a way to close a view panel, in particular the horizontal at the bottom, is pretty useless to me at this moment. What are the rules about take a bike on the London Tube? Can I take a bike on the Tube (underground) in London, if so how much does it cost? About the term $-\nabla_{[u,v]}w$ in the definition of Riemann curvature tensor How do I search events between two set dates inside WP? This is a  about DNS (Domain Name Service).   If my understanding of the DNS system is correct, the .com registry holds a table that maps domains (www.example.com) to DNS servers.   What is the advantage? Why not map directly to an IP address? If the only record that needs to change when I am configuring a DNS server to point to a different IP address, is located at the DNS server, why isn't the process instant? If the only reason for the delay are DNS caches, is it possible to bypass them, so I can see what is happening in real time? When a person lifts a book while standing on the earth's surface. Why is his force considered external to the book-earth system? Isn't his force internal like the case of the forces that cause the exploson of a bomb. I think the forces the person exerts on both the book and the earth are internal since they are equal but opposite therefore resulting in the position of the centre of mass of the system being maintained and if i'm right is the mechanical energy of the system constant?  Am i wrong? Please correct me. What is the correct name to use with /give for Lapis Lazuli? This is a school-network.  Official (outside reachable domain name) is  bgschwechat.ac.at (www.bgschwechat..., mail.bgschwechat... and ftp.bgschwechat..)  Internally the windows domain is named bgs.ac.at  We need (possibly cheap) SSL certificates for Webserver and Exchange-Server  From our firewall (www.bgschwechat.ac.at) (Sophos UTM9) requests get NATed to virtual machines - some of them need SSL   Webserver (running CENTOS - www.bgschwechat.ac.at) Exchange Server (named xch.bgs.ac.at) should be reachable via NAT as mail.bgschwechat.ac.at WSUS Server (dc2.bgs.ac.at) - only for internal clients   My question: What kind of SSL-Certificate would we need to secure eg. both domains (bgschwechat.ac.at AND bgs.ac.at) so that they appear secured from outside when NATTING for example mail.bgschwechat.ac.at to xch.bgs.ac.at ?  Or do we need to rename the interior domain to the official domain name?  ...recommandations where to purchase such certificate? How do I remove the space between inline/inline-block elements? When should I use "when" and "while"? But you can't find anything while you're crying.   But you can't find anything when you're crying.   I'll tell you about it while Frank saddles the horse.   I'll tell you about it when Frank saddles the horse.     When should I use when, and when while? Are these sentences correct? In ZFC set theory, every element object is a set. We know or feel that if $X$ and $Y$ are sets, their cartesian product $X\times Y$ is a set.  My question is: Why if $X$ and $Y$ are sets, their cartesian product $X\times Y$ is a set?