Is there a non jailbreak firewall for the iPhone or is there some way to set one up, somehow?
Does iOS support a built-in firewall like macOS does? I don't see anything about it in Settings.
Why isn't the center of the galaxy "younger" than the outer parts? I understand that time is relative for all but as I understand it, time flows at a slower rate for objects that are either moving faster or objects that are near larger masses than for those that are slower or further from mass.  So, the illustrative example I always see is that if I were to leave earth and fly around at near light speed for a while or go into orbit around a black hole the time I experience would be substantially shorter than for those I left behind at home on earth and I'd come back to find that I've only aged however long I felt I was gone by my own clock but that on Earth substantially more time would have elapsed.  Following through on this model, the stars in orbit around the black hole at the center of the Milky Way are aging much much slower (relative to us), right?  So does it not follow that the center of the galaxy is some appreciable (I have no idea how to go about putting this in an equation so will avoid guessing at the difference) amount "younger" than the stuff further away from the center?   If this is not true, could someone please explain why not, and if it is true, can someone please point me to where I can calculate the age of the center of the galaxy :-)  And to be clear... what I'm asking is... if there was an atomic clock that appeared at the center of the galaxy when the center was first formed, and we brought it through a worm hole to earth today - how much time would have elapsed on that clock vs. the age we recon the galaxy currently is? (13.2 billion years) Induction: Prove that $4^{n+1}+5^{2 n - 1}$ is divisible by 21 for all $n \geq 1$. Induction: Prove that $4^{n+1}+5^{2 n - 1}$ is divisible by 21 for all $n \geq 1$. Is there a way to programmatically determine if a font file has a specific Unicode Glyph? I'm working on a project that generates PDFs that can contain fairly complex math and science formulas.  The text is rendered in Times New Roman, which has pretty good Unicode coverage, but not complete. We have a system in place to swap in a more Unicode complete font for code points that don't have a glyph in TNR (like most of the "stranger" math symbols,) but I can't seem to find a way to query the *.ttf file to see if a given glyph is present.  So far, I've just hard-coded a lookup table of which code points are present, but I'd much prefer an automatic solution.  I'm using VB.Net in a web system under ASP.net, but solutions in any programming language/environment would be appreciated.  Edit: The win32 solution looks excellent, but the specific case I'm trying to solve is in an ASP.Net web system.  Is there a way to do this without including the windows API DLLs into my web site? Autocovariance of an ARMA(2,1) process - derivation of analytical model for $\gamma( k)$ How many characters have appeared in both Marvel and DC comics? The  (the character from Guardians of the Galaxy) says that she has appeared in both Marvel comics as Mantis and DC comics as Willow because her creator "took her with him".     After leaving Marvel Comics, writer Steve Englehart carried Mantis' tale through two other companies before returning to Marvel. In DC Comics' Justice League of America #142, she appears as Willow. Asked where she came from, Willow replies, "This one has come from a place she must not name, to reach a place no man must know." (Mantis refers to herself as "this one").   Are there any other examples of a character appearing in both Marvel and DC comics?  Especially if it's because the original creator has switched companies but still wants to utilize the same character, even under a different name? I've been thinking about switching to Ubuntu full time, but there are still some programs left behind that I haven't found any equivalent to yet. Does anyone know of a music player similar to Foobar2000 (I've read it doesn't handle well in WINE)? Proving $(A\le B)\vee (B\le A)$ for sets $A$ and $B$ Is transferring to another university an option for an unhappy PhD student? I've heard of people transferring between graduate schools because of their advisor moving to another school and taking their students with them.   Do students ever transfer for other reasons? If a student isn't happy at the school they choose, could transferring be an option? Presumably they would frame it as something positive such as "turns out I really want to work with Professor X" rather than "I hate my school", but does this ever happen? Is there a certain timeframe in which this is possible? (Assume it's a 5 year PhD program.)  If the answer varies by subject please mention the subject in your answer.  (Context: many friends have told me that if it turns out I'm not happy with my choice, I can always transfer. My impression is that this is actually difficult since many schools don't accept transfer students and in any case not being able to stick with a program looks bad -- but I don't have evidence either way so wanted to ask people who are in academia. Of course the ideal would be to pick a school one is happy with in the first place!) Domain of ProbabilityDistributions Cannot invoke method or retrieve property from null object. Object returned by the following call stack is null. \"File\r\n\" Why is it important to apply transformation to an objects data? I've watched several tutorials and very often they applied the location, rotation or scale to the object when they transformed it in Object Mode. They always said it is important, but why? I frequently find myself needing a word to express happiness that acknowledges a tragic or unfortunate circumstance underpinning that happiness. Preferably the word could have both adjective and verb forms. For example, "Gregory [verb-ed | felt adjective about] the balmy February day, suspecting it was yet another consequence of catastrophic and irreversible climate change."  "Bittersweet" is close, but not precisely right. It implies ambivalence rather than genuine gladness. "Schadenfreude" is also in the neighborhood, but I don't want to imply that the tragic part of the situation is what causes the pleasure. (Also, I recognize that the word may not quite exist in English, and I don't know if this is forbidden for this forum, but I'd welcome a loan word or phrase if there's a better one.) Can a 3rd party app *technically* take better pictures? I've seen in several forums that some phones have very good cameras and the photos  taken are compressed too much and the details are lost.  I was wondering whether a 3rd party application (forgetting the post processing done by the application) have access to the full resolution image without any compression.  So can another application access the raw data from the camera or all applications gets the same raw data when they access the camera? What do we know about the Ainur who stayed in the Timeless Halls? I'm setting up a Cronjob that will backup a MySQL database I have in my server, but I don't want it to keep overwriting the same file over and over again. Instead, I want to have an array of backups to choose from, done automatically. For example:  ## Cronjob, run May 21st, 2011: mysqldump -u username -ppasword database &gt; /path/to/file/21-03-2011.sql  ## SAME Conjob, run May 28th, 2011: mysqldump -u username -ppasword database &gt; /path/to/file/28-03-2011.sql   And so on.  Is there any way that I can use the system date and/or time as some kind of variable in my Cronjob? If not, what are your suggestions to accomplish the same? It's not like there's anything else to do.   Shouldn't the speaker say: "There's something else to do." ? so what's the meaning of the sentence and what's the difference between the two of them? Thank you, EM wave generation from different frames of reference After upgrading from Ubuntu 13.04 server, the www pages won't display themselves.     Error 403 Forbidden You don't have permission to access / on this server.   I've changed access control saves from apache2.2 to apache2.4, but that didn't work. What else could I do? I understand monsters only spawn in a 9 x 9 grid of chunks centered on the player, and I assume they stay around while they remain within that distance of you. But do they despawn as soon as you move away from them? Or do they remain? If so what (if anything) causes them to despawn? Are the rules any different for passive mobs?  Will running far away from an area and then coming right back clear it of monsters? I have a directory on my Windows 7 machine that has hundreds if not thousands of sub-directories.  Some of them have files, some do not.  I want to delete all the empty directories.  Looking at the del and rmdir DOS command, it does not look like you can recursively do this without deleting all the files.  Is there a way to do this from the command line?