Do black holes exist?
How long does it take for a black hole to form for an external observer?
I was getting the usual 4-8mbps in 12.04 when copying files via usb sticks. However after upgrading to 12.10, I only get 200-300kbps when I try to perform the same operation.   I have tried different usb sticks (which work flawlessly on Windows 7) and still experience the same issue. I experienced the same issue sometime ago on 11.10 but everything was normal when I upgraded to 12.04 so it might be a kernel issue.  Here's the output of dmseg |tail:      mysterio@mysterio-HP-Pavilion-dv6700-Notebook-PC:~$ dmesg |tail   [  871.023093] sdb: sdb1  [  871.026909] sd 5:0:0:0: [sdb] No Caching mode page present  [  871.026920] sd 5:0:0:0: [sdb] Assuming drive cache: write through  [  871.026927] sd 5:0:0:0: [sdb] Attached SCSI removable disk  [ 1036.226206] ISO 9660 Extensions: Microsoft Joliet Level 3  [ 1036.233561] ISO 9660 Extensions: RRIP_1991A  [ 1086.342973] ISO 9660 Extensions: Microsoft Joliet Level 3  [ 1086.343010] ISO 9660 Extensions: RRIP_1991A  [ 1173.971357] ISO 9660 Extensions: Microsoft Joliet Level 3  [ 1173.971441] ISO 9660 Extensions: RRIP_1991A   I have updated my system with the latest updates. What could be wrong? Define $S\equiv\{ x\in \mathbb{Q}\mid x^2<2\}$. Show that $\sup S=\sqrt{2} $. How would you handle different aspect ratios in a 2d platformer? prominently sports purple hair.    Is this her natural hair color?  Natural extensions in the answer depending on the correct answer: Is she wholly human and humans in the Galaxy Far Far Away can have this hair color?   Or is she partly human or not human?   Or does she dye her hair?   Or is there another hair color changing technology? Does this exist: software for noise cancellation Stopping resetting of linked locators in manipulate Is it possible to add multiple materials to a text object? I know that for a mesh you can go into edit mode and select vertices and assign a specific material to them quite easily. I want to know if it is possible to do this with a Text object (which has no vertices). Indentation shortcuts in Visual Studio filling area between 2 functions, with shading Retry a task multiple times based on user input in case of an exception in task Simple Past vs. Present Perfect: "was" vs. "has been" Possible Duplicate:          As a English non-native speaker it is difficult for me to understand when I must use present perfect or past simple because in my official language there isn't the present perfect tense. I know that present perfect is related to something that happened in the past but its result is important now. But for instance:        The message has been sent.   The message was sent.      Please help me point me out any examples/contexts where I should use 1. instead of 2. I'm using Terminator version 0.97. Is there a way that I can scroll unlimited? In the current version I only can scroll back limited history A commutative ring is a field iff the only ideals are $(0)$ and $(1)$ Let $R$ be a commutative ring with identity. Show that $R$ is a field if and only if the only ideals of $R$ are $R$ itself and the zero ideal $(0)$.  I can't figure out where to start other that I need to prove some biconditional statement. Any help? Dropping one of the columns when using one-hot encoding My understanding is that in machine learning it can be a problem if your dataset has highly correlated features, as they effectively encode the same information.  Recently someone pointed out that when you do one-hot encoding on a categorical variable you end up with correlated features, so you should drop one of them as a "reference".  For example, encoding gender as two variables, is_male and is_female, produces two features which are perfectly negatively correlated, so they suggested just using one of them, effectively setting the baseline to say male, and then seeing if the is_female column is important in the predictive algorithm.  That made sense to me but I haven't found anything online to suggest this may be the case, so is this wrong or am I missing something?  Possible (unanswered) duplicate: How to type en-dash and em-dash in Windows 7/8? I write blog posts, and I often need to type en-dash (–) and sometimes em-dash (—) in my blog posts. Currently I keep these characters saved in a text file, and copy-paste them whenever I need them. Unnecessary to say, it is a headache to move between keyboard and mouse when you type large texts.  It would be better for me if there ware a keyboard shortcuts available for these two characters. Is there a way to type en-dash and em-dash in Windows? I use Windows 7 and Windows 8 in different computers.    Here's an aligned comparison of dashes, if you need to see the difference for some reason.   Here's-dash Here's–en-dash Here's—em-dash How do I check the integrity of a storage medium (hard disk or flash drive)? Uses of the 3D Cursor I know the 3D Cursor can be used to position new objects, or snap existing ones to a certain location - but what else can it be used for?  An exhaustive list of every possible use would be great (without repeating similar things like "pivot for spin tool", "pivot for screw tool" - which could simply be said as "Pivot for modeling tools"). Sending a simple TCP message using Netcat I am trying to use netcat to send a simple message over TCP, e.g. I want to send the digit 1.  So I understood that I write the following in the terminal, after installing netcat  netcat [ip-address] [port]  But how do I specify the message to be sent? i.e. where to I write "1" ? Terms for collections of animals As I watched the murder of crows sitting on the line above my house this evening, I got wondering where all of the collective nouns for animals (pod of whales, gaggle of geese, pride of lions) came from and why we need so many.    If sheep can be a flock, why can't whales, geese, lions, and crows? What's the action of banging two beers together called?