What covers a sensor, and what can we clean it with?
What is the best way to clean the sensor on a interchangeable lens camera (mirrorless or digital SLR)?
Today while troubleshooting a service broker problem, I discovered that the database owner was the Windows login of an employee who had left the company. His login had been removed and thus the query notifications were failing.   Supposedly the best practice for dealing with this is to make 'sa' the database owner. We changed it and that cleared out the queue.   My (very elementary) question: what is the database owner and what is its purpose? Product of square of distances from vertices of a polygon of radius a I want to find out the following product.  $\prod_0^{n-1}  (r^2 + a^2 -2ra\cos(2k\pi/n - \theta))$ I have been trying to use complex numbers but did not work out. The book I am reading the result is directly stated as $r^{2n} + a^{2n} -2r^na^n\cos(\theta)$. Please help. Cooking steak in frying pan, problem with oil splatter I was using canola oil and put the stove top setting on "high - 9". I read plenty of guides suggesting there will infact be oil splatter, but it was pretty excessive and burning my arm with one drop getting near my eye before I stopped. I turned the heat setting down to "medium - 4", where the oil splatter seemed to drop substantially. Before I try to make steak again I'd like to get some clarification  So my questions are:   Which heat setting am I supposed to use? Is that type of oil splatter normal or should I try using a different oil, and if so, what oil? Should oiling the meat instead of the pan help the problem? Tag info not updated regularly on profile? From my , I learned that all tag related info on profile will be updated daily at UTC 03:00.  However, something is wrong here. It's now UTC 05:00+, but my tag number, say 93 (c++) is not updated against yesterday. I am pretty sure about this and I did earn some more points throughout the day. Sorry for not be able to capture the screenshot yesterday, but I did check this number 10 hours ago (which belongs to yesterday, also 93).  Is there a bug happening here? Or updating time different?    UPDATE: As of 24 Jan, the tags are still not updated with the proper values.  UPDATE2: Fixed around 25 Jan, UTC 03:00, at least for me. Running this script on: "Red Had Enterprise Linux Server release 5.11 (Tikanga)"  Mail is: version 8.1 6/6/93 (appears quite old).  Have tried various things and cannot seem to get this to work..  echo "Email message" | mail -a /home/user/checks/notprocessed.txt -a /home/user/checks/dirlist.txt -s "Subject" recipient@company.com /home/user/checks   Resulting message:     mail: invalid option -- a   mutt is not installed and I have limited access to this system as it is owned by the company I work for.  I could add in other components, but has to go through change management, and related processes.  uuencode is not available either.  Here is what I am using today and I am trying to add a second file to:  if grep 'Not Empty' /home/user/checks/notprocessed.txt    then    echo "files were found";     SUBJECT="NIGHTLY DIRECTORY LISTING OF FILES SENT TO VENDOR";    FROM="SENDER&lt;sender@company.com&gt;"    # EMAIL="JOHN DOE&lt;recipient@company.com&gt;"    EMAIL="MARY DOE&lt;recipient@company.com&gt;";    /bin/mail -s "$SUBJECT" "$EMAIL" -- -f "$FROM" &lt; /home/user/checks/notprocessed.txt /home/user/checks/dirlist.txt     exit -20 fi   And..  /home/user/checks/dirlist.txt is not attached or included as part of the e-mail.  I would like /home/user/checks/dirlist.txt to be actually an attachment  This actually does work - but includes the notprocessed.txt as the body of the email..  if grep 'Not Empty' /home/user/checks/notprocessed.txt    then    echo "files were found";     SUBJECT="NIGHTLY DIRECTORY LISTING OF FILES SENT TO VENDOR";    FROM="SENDER&lt;sender@company.com&gt;"    # EMAIL="JOHN DOE&lt;recipient@company.com&gt;"    EMAIL="MARY DOE&lt;recipient@company.com&gt;";    /bin/mail -s "$SUBJECT" "$EMAIL" -- -f "$FROM" &lt; /home/user/checks/notprocessed.txt     exit -20 fi Windows 10 64-bit requirements: Does my CPU support CMPXCHG16b, PrefetchW and LAHF/SAHF? I'm currently trying to find out whether or not it would be a good idea to update my slightly dated notebook (Windows 7, 64-bit) to Windows 10. The problem is that Microsoft states in their  that to use the 64-bit version of Windows 10, a processor which supports CMPXCHG16b, PrefetchW and LAHF/SAHF is needed. I know that my processor is 64-bit (Intel Core i5-2430M @ 2.40 GHz) but I don't know how to find out whether it supports CMPXCHG16b, PrefetchW and LAHF/SAHF, and I have no idea what these mean.  I tried using Google and got no results that made sense to me, only some comparison of my i5 and a similar AMD processor. I also checked Intel's ARK website. If somebody could point me to where I can get more info I would be really grateful. Multiple entry visa to UK (sponsored visitor) Over time I realized a very annoying property of the Stack Overflow reputation system: Easy answers to popular question are rewarded with a lot more reputation points than actually great answers. In case anybody actually needs examples for this, here are two examples from :   gained me 420 rep, I invested 2 minutes writing it, and it only was a wild guess.   took me about an hour for the research and the math and gained me 40 rep.  Now I know that you are bound to get more rep for answers that are useful to more people, and I'd say that's fine. But the current situation is quite extreme: 30% of my reputation is from 5 of my 330 answers, and they are definitely far from being my best ones.  A final example that is not from my profile, but more extreme: Do you really think  is worth 40000 reputation?  My proposition to improve that situation would be to make the reputation gain from a single answer non-linear, maybe even have it capped at a certain point. I'm not sure on how that non-linear function should look exactly, and would leave good proposals for that to users with more experience than me. I have recently upgraded SQL Server 2000 database to 2008 R2.    What I did was:   Shutdown SQL Server 2000 (express) service on old machine, Move datafiles (mydatabase.mdf and mydatabase.ldf) to new machine, Run SQL Server Management Studio 2008, Connect to local database engine, Attach datafiles to database. Change the compatibility level of database to SQL 2008 (100).     Question: What else should I do to make migration complete?  I want to:   use new features like checksumming and full recovery model, make this database to be exactly as it was created in SQL 2008 R2, make this database to be fully compatibile, correct and be perfect suited for new, SQL 2008 R2 database engine.     In other words: I just want to know how to correctly and completly convert old SQL 2000 database to new 2008 R2 database, be calm that everything is done right and be happy with all new features.    I'm asking this question, because I've found a lot of sites on the Internet that says so many different things that makes me confused: some say that it is required to rebuild indexes, another says to do other things... and now I know nothing so I want to hear experienced person opinion and clear, step-by-step instructions. I work for very small company, I'm on my own and I don't want to screw things up.    Sir, I'm really impressed with your answer, I wasn't expecting so much.    So some comments:   The database is now in production. As I said, it was upgraded using deattach-attach method as I desribed in first post and as described on MSDN:  It had to be done quickly, so I was forced to do it that way. Let's forget about how inappropriate could it was and focus on current situation. The users/persmission is not a problem here - there are only few and permissions are simple. The application which use database is compatibile with SQL 2000 till 2012 so this is not a problem either. The database file (MDF) isn't big - only about 1GB.     Few more questions:   You recommend to use backup/restore method, but I did as written above, so can I encounter any problems now? Everything worked without any problem. About checksumming and full recovery model: it wasn't available/enabled on SQL 2000, so I want to use them now. You said that the only thing I need to do is to enable those options in database properties? I've read somewhere, that it isn't enough and I should also rebuild indexes or something. I really don't know, I just asking. I'm prepairing to migrate this database to SQL 2012 - so first it was from SQL 2000 to 2008 R2, now it will be from 2008 R2 to 2012 (it was impossible to do this directly because of lack of support of SQL 2000 databases in SQL 2012). So I understand that I should follow your guide: backup it in 2008 R2 and restore in 2012, then do the rest of your tips, right? Please explain me the backup/restore method: Is it like a dump of database to SQL queries and then restoring it by executing a bunch of queries? Will this method by the way "defragment" my database? If not, how to defragment/optimize it manually? As we were using SQL 2000 Express for years (no management interface), we were doing backups simply by stopping engine and RAR the DATA directory. For now, as we are on SQL 2008, isn't this still better than using backup function in Management Studio? Full recovery mode with frequent Transaction log backups - Where is the Transaction log stored - is it the LDF file? How sould I backup it properly?     I know that my questions may sound silly, I'm not professional database admin, but I am the only person here who can do such "hard core" task like upgrading the database engine. I'm also sure that your knowleadge will help a lot to other people like me.  Thank you very much for your time and knowleadge, I really appreciate this. 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. I am not talking about miracles, religious revelation, or artistic expression, but something more mundane. There is a lot of "empirical" evidence that the Riemann hypothesis is true, the scare quotes indicate that the source of the evidence is "mathematical intuition". In psychology there are mental states that no one sees, touches, hears, smells or tastes, qualia with their perceptual fullness that can not be conceptualized or directly communicated, and abilities/skills "know how" with the same problem. In linguistics Kripke's theory of reference relies on "modal intuitions" to decide the truth of counterfactuals. But an empirical counterfactual is an oxymoron, especially when it is embedded into an entire "possible world".  Freudian psychoanalysis and Husserlian phenomenology are attempts to deal with some of them systematically, but they are traditionally confined to the fringe of science at best. The mainstream approach is empirical second hand, but behaviorism in psychology and linguistics, and nominalism in mathematics, were not very productive.   According to the naturalized epistemology there is no a priori "first philosophy" of science, methodology is subject to the "tribunal of experience" and revision, just as the science itself. Should it apply to non-empirical experience? Sense empiricism has served science well for centuries, and was fully embraced by Quine.  takes him to task for it:     "Cognitive science is an empirical science working to unearth the mechanisms through which natural language constitutes itself. That account has had to recognize the indispensability of mental states, of beliefs, if it is ever to become adequate to the problem... There is still too much "first philosophy" in Quine. We must rescue naturalized epistemology from its own founder".    Note the use of "empirical" together with "mental states".  Questions: Does naturalized epistemology dictate that natural science should relax sense empiricism, and approach non-empirical phenomena partly first hand? If so, how can the scientific method be adapted to introspective/intuitive phenomena that are not readily reproducible, manipulable, measurable, and/or publicly accessible? What would play the selective role of empirical testing? Can there be non-empirical (more likely, not entirely empirical) natural science? How do you send a HEAD HTTP request in Python 2? What I'm trying to do here is get the headers of a given URL so I can determine the MIME type. I want to be able to see if http://somedomain/foo/ will return an HTML document or a JPEG image for example. Thus, I need to figure out how to send a HEAD request so that I can read the MIME type without having to download the content. Does anyone know of an easy way of doing this? Is it possible to detect a player consuming food items? Get latest Flash player on Ubuntu I know, it's been asked before but I couldn't really get a satisfying answer for some details/backgrounds and I guess it's an important question for many.    Some application seem only to be running with Adobe Flash 15 (or at least I know it does, because I have that version on my Windows Partition).  The official Adobe website says:     NOTE: Adobe Flash Player 11.2 will be the last version to target Linux as a supported platform. Adobe will continue to provide security backports to Flash Player 11.2 for Linux.   Some search on the web like "Ubuntu Adobe Flash 15" or similar does not return any good websites.  I found something that says   (using a "pepper-based version"), and  .   Is it impossible to use this for Firefox too? Would it be a privacy risk?  Are there no alternative projects (I know it's closed source but there are so many so very bright people out there using something similar to wine but just for the plugin....)?  How about the Mac-Version? Shouldn't someone be able to port that one to Linux? Area 51 is miscounting my proposal followers I know of one person who is following my proposal who doesn't show up on the proposal webpage.    My proposal is for quantitative finance: .  It shows 19 people following the proposal (on the side of the page), and the total listed at the top of the page is 19 followers.  Yet one user is not listed: .  This makes me wonder if other followers are also not being counted? Apostrophe difference (Ones' and Two's Complement) bash - problems reading text file and printing line by line Non academic career options for PhD in Math I am thinking of getting my M.S. in Computer Science. I chose C.S. because I enjoy programming and because its a solid choice, career wise.  Low unemployment, good pay, all that jazz.  But my real passions has always been math and lately I have been thinking about swapping and going for my graduate degree in Math. If I went the math route I would probably go full PhD (since I don't think there is much you can do with just a Masters in math).  But as much as I love math, I can't see myself being a math teacher. I would want to work in research or industry, applying math to solve real world problems.    What kind of non-academic jobs are there for someone with a PhD in math (or what is the best resource to see what jobs are out there)? Why is ++i is l-value and i++ not? Model a simple 3D spiral shape? I need to model a simple spiral shape. I imagine the best way to do this is with curves, but I am unsure how to create a perfect spiral shape with curves. What's the best/easiest way to make a spiral tube?