How will I upgrade Ubuntu 12.04 to 13.1 internally without the iso file . Please help .
I am currently using Ubuntu 10.04. I know there is a 10.10 release, but can I upgrade directly to 11.04? Could you walk me through the steps please?
What is the relativistic calculation of travel time to Proxima Centauri? It has already been  how fast a probe would have to travel to reach Alpha Centauri within 60 years.  NASA has done  into a probe that would take 100 years to make the trip.  But I am interested in this question from a slightly different perspective.  I would like to know how long the trip from our solar system to Proxima Centauri would take for both a ship and for an observer on Earth while accounting for the effects of general relativity on a .  The following assumptions may be made:   The ship starts and ends at 0 km/s relative to the Earth observer. The ship experiences a constant force of acceleration of 20 g until the half-way point and then a constant force of deceleration of 20 g until the destination. The path traveled is such that accleration is in only one spatial direction. The distance traveled is 4.25 light years.   Calculate (accounting for general relativistic effects):   Time of trip for Earth-based observer. Time of trip for ship-based observer. Maximum speed.   You don't need to consider mass, or life-support systems, or method of propulsion; I am really only interested in the effects of relativity on the perceived time of the trip. A regular function can contain a call to itself in its definition, no problem.  I can't figure out how to do it with a lambda function though for the simple reason that the lambda function has no name to refer back to.  Is there a way to do it?  How? To date I have had an Apple ID tied to my personal email address. It uses my personal paypal account for the purchases, and currently it has a credit balance thanks to some Christmas iTunes gift cards.  With the App Store recently being released, I'd like to buy an OS X app for business purposes. I don't want to use the credit balance on my personal Apple ID account, so I was thinking about creating a new Apple ID just for when I buy apps that I use for business. This way I could have the business Apple ID tied to my business paypal account.  However, I'm concerned that there might be some gotchas with using two different Apple IDs on the same MacBook by the same user. Before I just try this blindly, does anyone have any experience or know of any gotchas? How to create functions of arbitrary number of variables? Does lower resolution result in better signal-to-noise ratio, given the same sensor size? With the release of the Canon EOS R5/R6, there have been many saying that they prefer the 20MP R6 camera over the 45MP R5 camera, due to its lower price but also because of &quot;better low-light performance.&quot; In camera comparison sites, I've also seen the sentiment that bigger pixels (lower resolution) = better low light performance. However, is this a myth? Here is my reasoning for this. Let's say that there are two full-frame sensors, one 20MP sensor and a 80MP sensor. According to many people, the 80MP sensor would be terrible for low-light photography since the pixels are smaller. However, each 2x2 block in the 80MP sensor could be mapped, and in post averaged to a 1x1 pixel, effectively making the image into a 20MP image. This could also be done in-camera as an option. Would this image have just the same amount of usable information as the image from the 20MP sensor? In other terms, since both sensors are 35mm sensors (i.e. equal area), the amount of light falling onto the sensor is the same. So, at the end of the day, there will be no difference between a 20MP image and a 20MP image that has been downsampled from 80MP, right? So their low-light performance would be the same. You even get an advantage from having the option to get 80MP photos if you wanted. Why do people say that a lower-resolution camera has better low-light performance, when it should theoretically be the same as one with higher resolution (all other factors equal)? Note: this question is about sensors with the same size but with different pixel density. Hence, it is different from  asking about different sensor sizes. I am aware that a full-frame camera will have better low-light signal due to its bigger area than an APS-C sensor, but what about the similarly sized sensors? I have a basic doubt about the associativity of the cartesian product. Well, first wikipedia says that the cartesian product isn't associative, and there's a good argument for it: if $x\in E$, $y\in F$ and $z \in G$ the identity $((x,y), z)=(x,(y,z))$ would imply that $(x,y) =x$ and $(y,z) = z$ so that $((x,y),z)=(x,y,z)$ would mean nothing.  That's fine, I like this argument. However, in his book Calculus on Manifolds, Spivak says that the cartesian product is associative. He says: if $A \subset \mathbb{R}^m$, $B\subset \mathbb{R}^n$ and $C \subset \mathbb{R}^p$ then $(A\times B)\times C = A \times (B \times C)$, and both of these are denoted simply by $A \times B \times C$.  Well, this confuses me because Spivak is always very rigorous, so that he wouldn't state something that's not true in such way. Is Spivak or Wikipedia right ? Or Spivak's statement only works for subsets of euclidean spaces ?  Thanks in advance and sorry if this question is too basic. C# 4.0 optional out/ref arguments Cannot locate Ubuntu Software Center via Firefox to open APT links In the new canon what do we actually know about Darth Plagueis? I read and loved  but with all the recent changes to what is and isn't canon I'm losing track.  There's a common theory that Supreme Leader Snoke is Darth Plagueis, most are discounted because Plagueis is a Muun. But where does that information come from? What current canon information do we have about Plagueis that disproves this theory and what has been marked as Legends? NS list does not match list from parent zone I'm attempting to figure out an error message that I got from dnsstuff.com when examining my DNS records.  The error reads as follows.     NS list does not match list from parent zone. This should be addressed because queries for this domain may require an extra lookup (and more overhead) because there is no direct relationship between the NS records at the parent and the NS records at the authoritative servers. This can cause delays. The mismatched NS list is:      nameserver ns1.domain.co. | xxx.xx.xxx.xxx is missing NS2.domain.co. | yy.yyy.yy.yyy   There are a couple questions I have regarding this.   What is the difference between a parent and authoritative zone?  In other forum posts I've seen, the seem to be used interchangeably (although that could be my misperception). What does it mean for the NS list not to match the list from the parent zone?  What is "the list from the parent zone" to which they refer? How might you recommend that I resolve this?   In case this affects any answers, I'm running Virtualmin on Ubuntu 12.04.  Any help is appreciated.  Many thanks in advance! How to randomly subset X% of selected points? How do you import CA certificates onto an Android phone? I want to connect to my University's wireless using my Nexus One. When I go to "Add Wi-Fi network" in Wireless Settings I fill in the Network SSID and select 802.1x Enterprise for the security and fill everything out.  The problem is that our university's wireless uses Thawte Premium Server CA certificate for certification.  When I click the drop down list for CA certificate I get nothing in the list (just N/A)  Now I have the certificate (Thawte Premium Server CA.pem) and have moved it to my SD card, but it doesn't look like Android automatically detects it.  Where should I put the certificate so that the Android wireless manager recognizes it. In other words, how can I import a CA certificate so that Android recognizes that it is on the phone and displays it in the CA Certificate drop down list.  Thanks for any help,  Tomek  P.S. My phone is not rooted  EDIT: After doing some research it looks like you are able to install certificates by going to your phone's settings > Location &amp; Security > Install from SD card  Unfortunately it looks like the only accepted file extension is .p12. It does not look like there is a way to import .cer or .pem files (which are the only two files that come with the Thawte certificates) at this moment.  It does look like you can use a converter to convert your .cer or .pem files to .p12, however a key file is needed.    I do not know where to get this key file for the Thawte certificates. Operators can be cyclically interchanged inside a trace: $${\rm Tr} (AB)~=~{\rm Tr} (BA).$$ This means the trace of a commutator of any two operators is zero: $${\rm Tr} ([A,B])~=~0.$$ But what about the commutator of the position and momentum operators for a quantum particle? On the one hand: $${\rm Tr}([x,p])~=~0,$$ while on the other hand: $$[x,p]~=~i\hbar.$$ How does this work out? Location of /etc/fstab in El Capitan I want to activate the . But I can't find the /etc/fstab on my mac. osx 10.11.5 El Capitan Accepted way to abbreviate cities that have "Saint" in their name My first question here, so I'm not sure if this OT or not, so please bare with me.  Background: I don't live in US. I'm working with some data that I'm pulling from . Sometimes, I'm getting a city name as St. John and sometimes as Saint Ann.   So my question is, is there an accepted way on how people write a US city names which starts with Saint or is this just some random thing (or just specific to AdWords maybe)?  I'm asking this, because if for example I'll get both St. John and Saint John in the same file, should I consider them the same or should I be suspicious? Site specific magic comment links I would like site specific magic links. Currently you can write [so] in a comment, and it links like this: . I would like to be able to have site specific ones, so for example: English Language &amp; Usage  [dictionary] would go to http://dictionary.com and shows as   Ubuntu  [launchpad] would go to https://launchpad.net/ubuntu and shows as   [launchpad#bugnum] would go to https://bugs.launchpad.net/bugs/bugnum and shows as   [forums] would go to http://ubuntuforums.org/ and sows as   [discourse] would go to http://discourse.ubuntu.com and shows as   [paste] or [pastebinit] would go to http://paste.ubuntu.com and shows as   [install-d] would go to http://ubuntu.com/download/desktop/install-ubuntu-desktop and shows as   [install-s] would go to http://ubuntu.com/download/server/install-ubuntu-server and shows as   ppa:peterlevi/ppa would go to https://launchpad.net/~peterlevi and shows as   There is    Ask Different  [applesup] would go to http://www.apple.com/support and shows as   Christianity  [bible] would go to http://biblegateway.com and shows as   Currently, they are all the same, for all sites. I would like devs (mods maybe) to be able to add them on a per site basis. This is just a selection of examples. People can comment or answer with ones they would like and I'll edit them into this question. I asked this because  on Ask Ubuntu Meta wasn't possible right now - because it wasn't a feature.  [The devs] said right now it isn't possible because magic links are network wide, and they weren't sure it was high enough priority to really get done anytime soon, but if you want you can post a feature-request on Meta Stack Exchange requesting site specific magic links and see if you can garner more support for the feature and maybe get a dev to champion it.  So that's what I've done! I want to start using the terminal more often, but I don't know what are the different commands available to me. Is there a way to list all the different commands that I can make use of? Looking for a book series about a girl and her friends captured and sold as slaves I'm trying to find the name of a book series I read about 10 years ago. It might be a children/young-adult series since I was fairly young. There is also a small chance it was written by a french author, as I read it in french. The series is composed of at least three books, maybe more. Here is what I remember :   The main character is a poor girl/young woman, but there are several point of view characters At the beginning of the first book the plot is set in a city where rich people live in the city center and the further you go from the center the poorest people are. Moreover, the houses are painted according to the wealth of the owner. It was something like : the richer had red houses, the poorer blue houses, and the moderately wealthy purple (it was not those colors in particular but it was something like that) At the end of one of the book there is some kind of uprising and the people paint all the houses in multiple colorful shades (to symbolize the new found equality between the citizen) At some point the main character and other peoples of the city get captured (maybe after some kind of war the city was involved in), separated and sold to slavery One of them, an older boy, become a soldier and learn a special fighting technique that looks like dancing (and he grows to like it) Another of the captives, a young girl (the sister of the main character if I recall correctly) get marked with a fire-heated mark to show her condition of slave   That is all I remember, I have no clue about the time or geographic setting nor the story details.  I know it's not much to go by, any help would be greatly appreciated, as I would like to find these books and read them again. Search across Stack Exchange sites in Android app $(\mathbb R, \oplus)$ is a group. Define a multiplication with which we get a field. Where $a \oplus b = a + b +1$ I have this problem from the book Real Analysis of Miklos Laczkovich ():     Let $\oplus : \mathbb R \times \mathbb R\to \mathbb R $, where $(a,b) \mapsto a + b +1$. Then,  $(\mathbb R, \oplus)$ is a group. Define a multiplication with which we get a field.   But in the exercise there are no hints. Could anyone help me?