My lens broke somehow. I didn't drop it as far as I remember, but the cause of the drop isn't really the point... a part of my lens broke, and my lens cap is stuck to it. Is my lens a goner? Can I buy a replacement for the specific part or will I have to fork out the near $400 to replace it? Where is the best place to cry?  This is a Nikon D90 with an AF-S Nikkor 18-200mm 1:3.5-5.6 G II ED
Can I send in for repair a lens that has a shattered front element?     UPDATE: The front element was not shattered, it was the UV filter. Factory diagnosis: Lens assembly had been impacted; cleaned and checked.  Helpful notes by Crowley, David Richerby (x2), Michael Clark (x2), and   mattdm (on element price vs UV filter).      Canon cleaned and checked my lens back to like new quality for $179 labor, no parts, not including shipping.      Jim Garrison answered my question, but Crazy Dino has the best info all around for a lens element shatter.   Original Question:  I recently opened my camera bag to find a shattered front element on a Canon EF 16-35mm f/2.8 L II USM lens.   There are a lot of micro glass shards on the second element.  Does anyone have experience with this sort of thing?  Some of the following are questions I have:   Can I get it repaired? What will the cost be roughly? Will the lens ever work the same and have a good image quality? Should I ship it as is, or attempt cleaning it with air? Where is the best place to cry a little?   Thanks, any good info on this would be appreciated.  I will never rest a lens on another lens, I nearly lost a 24-70mm L that shattered a UV filter also.   Good reason to have a UV always, never thought it could happen to me.  Update: Looking at it more it looks like maybe just the front ring came undone and the UV filter broke?  I can't remember what it looked like exactly before.  I threw away the glass shards (polished sand) in the Nevada desert.      UPDATE: Primary reason for thinking more than just the UV was broken,   UV filter split into two rings, depositing the locking collar into the   lens barrel.
How do I use extern to share variables between source files? You can’t buy your kids clever. What’s more, if they’re merely above average, by sending them to some hideous Holland Park hothouse, you’re probably buying them miserable.  — Alex Proud,   ""   As far as I know, clever and miserable are both adjectives, not nouns. So why were they used with to buy? Is this an idiomatic way of saying You can't buy your kids intelligence and you're probably buying them (moral) misery? If so, what is the idiom used here? I'm not familiar with it. How to add a script to Startup Applications from the command line? Conditional Linq Queries We're working on a Log Viewer. The use will have the option to filter by user, severity, etc. In the Sql days I'd add to the query string, but I want to do it with Linq. How can I conditionally add where-clauses? What happens when many neurons have same weights? Does it make any sense to have two (or more) neurons in a neural network with the same weights? (intuitively it makes no sense, since all the neurons would behave the same way).   Please consider both the input and hidden layers. What if the weights are equal 0? What is the "Event Horizon" of a black hole How to draw a return arrow from node-3 to node-1 Quitting a job in the US on a work visa, going to Canada and re-entering on a tourist visa (ESTA waiver) I have been working in the USA on an E-3 visa and intend to return home to Australia, but I want to travel around the US before I do so. I am under the impression that after leaving my current company, I will have 10 days to leave the country.   Will I be able to go into Mexico or Canada and re-enter with an ESTA waiver as a tourist? Ubuntu system is broken after accidentally uninstalling many packages I accidentally removed all the packages starting with the name jpeg with:  sudo apt-get remove jpeg*   This screwed up a lot of things, removed Unity, Firefox, Flash player etc.  I somehow managed to recover the desktop and unity but then a lot of things are still buggy. For example .rpm files and .tag.gz just won't open up at all.  What I want is a way to fix everything that's amiss. Something that is the equivalent of a 'repair installation' with a windows disc.  Any tips, anyone? Why can't I paste § into a Minecraft command? Merge two custom post types into one admin page? I am building a site with 4 custom post types. To make things easier for our client/admin, I'm wondering if there is a way to merge those custom post types into one list in the backend? Like if you look at normal backend admin page with the list and columns of posts, can a page like that pull in 3 other post types for easy sorting/searching?  I can't combine the CPTs into one, they must remain seperate outside of one 'viewing' page in the admin area if possible.  Any thoughts on how to do this?? Or even where to start looking/thinkging of how to develop this? White cloudy areas on bottom of new stainless steel skillet I just bought my first few pot and pans "Calaphon" stainless steel trip-ply  I used my new 10" skillet tonight, and cooked pork chops. I heated the pan first, added olive oil, let it heat, then added chops. After I was done, cleaned it immediately under water, and noticed white cloud looking areas on the bottom of the skillet. They won’t wash or rub off  Do I need to return these? I did buy them for the look as well. I had installed VirtualBox but it started giving me problems. So I uninstalled it using:-  sudo apt-get remove virtualbox-\* sudo apt-get purge virtualbox-\*   But when I reinstalled VirtualBox it again resumed to previous settings and started giving same problems. How can i completely remove VirtualBox from my laptop and then reinstall it such that it wont give same problem again? When I was at school and learning integration in maths class at A Level my teacher wrote things like this on the board.  $$\int f(x)\, dx$$  When he came to explain the meaning of the $dx$, he told us "think of it as a full stop".  For whatever reason I did not raise my hand and question him about it.  But I have always shaken my head at such a poor explanation for putting a $dx$ at the end of integration equations such as these.  To this day I do not know the purpose of the $dx$.  Can someone explain this to me without resorting to grammatical metaphors? I'm a European citizen living in the US on a work visa. Due to some unfortunate circumstances, I need to urgently visit my home country. However I would like to get back to the US after my visit is complete. Flying from the US to Europe is not a problem as there are still daily flights between some city pairs. However going back could be tricky, as  anyone who has been in the Schengen area in the past 14 days from re-entering the country.   Is there a flight route that would let me from Europe to some country, stay there for 14 days and then fly to the US? Canada is out, as they've banned international visitors. Mexico seems to keep their border open, but I  any direct European flights from their airports. Almost every other country either suspended flights or doesn't allow foreign nationals to enter. I've upgraded from 12.04 to 14.04 via command-line when my system froze, had to do REISUB and dpkg --configure -a to recover from crash after rebooting.  Now everything seems to work except automatically mounting external thumb drives and external hard disk drives. After plugging in said drives, they fail to show up on the left pane and remains unmounted. I can see the device if I run lsusb and fdisk though, so it's possibly to manually mount it but I'd rather resolve why it's not automatically mounting. Prove Or Disprove: tr(AB)=tr(A)*tr(B) $\mathrm{tr}(AB)=\sum\limits_{i=1}^n \sum\limits_{j=1}^n a_{ij}*b_{ji}$  $\mathrm{tr}(A)*\mathrm{tr}(B)=\sum\limits_{i=1}^n a_{ii}*\sum\limits_{i=1}^n b_{ii}$  Therefore $\mathrm{tr}(AB) \neq \mathrm{tr}(A)*\mathrm{tr}(B)$  Is the proof valid? I'm still new to ZFS. I've been using Nexenta but I'm thinking of switching to OpenIndiana or Solaris 11 Express. Right now, I'm at a point of considering virtualizing the ZFS server as a guest within either ESXi, Hyper-V or XenServer (I haven't decided which one yet - I'm leaning towards ESXi for VMDirectPath and FreeBSD support).   The primary reason being that it seems like I have enough resources to go around that I could easily have 1-3 other VMs running concurrently. Mostly Windows Server. Maybe a Linux/BSD VM as well. I'd like the virtualized ZFS server to host all the data for the other VMs so their data could be kept on a physically separate disks from the ZFS disks (mount as iscsi or nfs).  The server currently has an AMD Phenom II with 6 total cores (2 unlocked), 16GB RAM (maxed out) and an LSI SAS 1068E HBA with (7) 1TB SATA II disks attached (planning on RAIDZ2 with hot spare). I also have (4) 32GB SATA II SSDs attached to the motherboard. I'm hoping to mirror two of the SSDs to a boot mirror (for the virtual host), and leave the other two SSDs for ZIL and L2ARC (for the ZFS VM guest). I'm willing to add two more disks to store the VM guests and allocate all seven of the current disks as ZFS storage. Note: The motherboard does not have IOMMU support as the 880G doesn't support it, but I do have an 890FX board which does have IOMMU if it makes a huge difference.  My questions are:  1) Is it wise to do this? I don't see any obviously downside (which makes me wonder why no one else has mentioned it). I feel like I could be making a huge oversight and I'd hate to commit to this, move over all my data only to go fubar from some minute detail I missed.  2) ZFS virtual guest performance? I'm willing to take a small performance hit but I'd think if the VM guest has full disk access to the disks that at the very least, disk I/O performance will be negligible (in comparison to running ZFS non-virtualized). Can anyone speak to this from experience hosting a ZFS server as a VM guest? Night's Watch deserters are sentenced to death, as we've seen in the very first episode of Game of Thrones. A man dressed all in black is apprehended by Stark men and brought before Lord Eddard Stark. Lord Stark sees him as a deserter and sentences him to die (and then executes that death penalty).  However, there are men of the Night's Watch south of the Wall, on a legitimate mission or on some kind of allowed leave. For instance, we have Benjen Stark visiting Winterfell when the king and his party is there. There is also Yoren, who travels around Westeros in search of new recruits.  I could imagine that the Warden of the North (and other lords in the northern part of Westeros) would have a good idea of who would be allowed further south and whose appearance would raise suspicion. But I reckon the southern lords don't have as many visits from the Night's Watch, so they might not know who would be allowed to be there and who wouldn't.  How would lords who are rather unfamiliar with the specific brothers of the Night's Watch discern deserters from brothers sent out for some reason?  That ends my question, but there is a spoiler from the season 5 finale that continues the question a bit more:      Sam is sent to Oldtown to become a Maester, so he can replace Maester Aemon at Castle Black.  But he is riding together with Gilly (a woman!) and her baby (a baby!), which might raise a lot of suspicion from people who don't know what he is sent out to do.  What prevents southern lords of sentencing Sam as a deserter from the Night's Watch? The sum of powers of two and two's complement – is there a deeper meaning behind this? Probably everyone has once come across the following "theorem" with corresponding "proof": $$\sum_{n=0}^\infty 2^n = -1$$ Proof: $\sum_{n=0}^\infty q^n = 1/(1-q)$. Insert $q=2$ to get the result.  Of course the "proof" neglects the condition on $q$ for this formula, and the sum really diverges. However I now noticed an interesting fact:  If you use two's complement to represent negative numbers on computers, $-1$ is represented by all bits set. Also, sign extending to a larger number of bits (that is, getting the same number in two's complement representation on more bits) works by copying the left-most bit (also known as sign bit) into the additional bits on the left.  Now imagine that formally you sign-extend the number $-1$ to infinitely many bits. What you get is an infinite-to-the-left string of $1$s. Which, using the normal base-2 formula $n = \sum_k b_k 2^k$ (where $b_k$ is the bit k positions from the right, i.e. $b_0$ is the rightmost bit), that infinite string of $1$s translates into exactly the sum above! So in some sense we have an independent re-derivation of that equation.  Now my question is: Is there something deeper behind this? Somehow I cannot imagine it is just coincidential.