I found out it is possible to run ubuntu on a USB. So thats what i tried and it worked. I wanted to test an express application but installing node js throws an error everytime. sudo apt install nodejs sudo apt install Nodejs  Error: E: Paket nodejs kann nicht gefunden werden. (German for &quot;Package not found&quot;) since today my only experience with linux was a 5€ a month server i bought and played around with Note: Any tipps for asking better questions in the future?
How can I install applications like Google Chrome on Ubuntu?  Are there any commands to install an application?    Index of answers:
How to sync bookmarks across Google Chrome and Mozilla Firefox bookmarks? Is there any meaningful distinction between:  class A(object):     foo = 5   # some default value   vs.  class B(object):     def __init__(self, foo=5):         self.foo = foo   If you're creating a lot of instances, is there any difference in performance or space requirements for the two styles? When you read the code, do you consider the meaning of the two styles to be significantly different? I noticed that Dolores Umbridge was born during the first Wizarding War, so it's very likely she wasn't a Death Eater then (but she is pretty evil -- who knows?).  After that Voldemort was not around in a way that could affect many people, and most wouldn't know he was planning to rise again.  During that time, and up through Voldemort's return (in Goblet of Fire), did Umbridge have any connection with the Death Eaters or with Voldemort?  Was she doing what she did on her own, or was it because of an association with Voldemort or his allies? When you respond to someone in a comment you use @PersonsName. Is there anyway it could be linked like this @ Incoming light reacts with the several types of cone cells in the eye. In humans, there are three types of cones sensitive to three different spectra, resulting in trichromatic color vision. Each individual cone contains pigments composed of opsin apoprotein, which is covalently linked to either 11-cis-hydroretinal or more rarely 11-cis-dehydroretina.  The opsins (photopigments) present in the L and M cones are encoded on the X chromosome.  A very small percentage of women may have an extra type of color receptor because they have different alleles for the gene for the L opsin on each X chromosome. X chromosome inactivation means that only one opsin is expressed in each cone cell, and some women may therefore show a degree of tetrachromatic color vision. Tetrachromacy is also demonstrated among several species of birds, fish, amphibians, reptiles and insects.  Humans cannot see ultraviolet light directly because the lens of the eye blocks most light in the wavelength range of 300–400 nm.  So, besides above mentioned exceptions, is it possible due to mutations or genetic engineering to see UV or infrared. What kind of mutations should be made or are the changes to be made in the opsines to big to create 'alien' eyes? I downloaded the July 30th update for Pokemon Go and when I open the app I'm prompted to login, But once I login, it redirects me to this page on Cookies::     If I click "Done" in the top left, it prompts me to login again! I've tried reinstalling the game, restarting my phone, etc. I can't much enable Cookies on the inline Safari browser. It doesn't make sense, and cookies are on in Safari (because I don't use Safari and they're enabled by default).  How can I fix this? I am a Indian citizen in the United States on a F-1 visa.  For the summer break, I am traveling (round-trip) from Chicago to New Delhi via Dusseldorf-Frankfurt by Lufthansa airlines. My onward Journey would be on July - 8 and return Journey on Aug - 11.  My layover will be of 1 hour 10 mins in Frankfurt and 3 hours in Dusseldorf.  I would like to know if I require Category A or Category B Visa. If not, what type of visa do I require for the Schengen visa for my transit. How I can apply for the same?  I tried to find slots in German consulate but all slots are full before my departure date. If I don't get the Schengen visa, I cannot travel and will loose all the fare (since my ticket is a non-refundable ticket). Is there any other way I can tackle this situation. Non-algebraically closed field in which every polynomial of degree $<n$ has a root My problem is to build, for every prime $p$, a field of characteristic $p$ in which every polynomial of degree $\leq n$ ($n$ a fixed natural number) has a root, but such that the field is not algebraically closed.  If I'm not wrong (please correct me if I am) such a field cannot be finite, by counting arguments. But on the other hand, the union of all finite fields (or of any ascending chain of finite fields) of characteristic $p$, which is what I get if I start with $F_p$ and add a root to each polynomial of degree $\leq n$ in each step, is the algebraic closure of $F_p$, hence algebraically closed. I don't see how I can control this process so that in the end I get a field that is not algebraically closed.  Any hint will be welcome. Thanks in advance. How to join a LAN / IPX game on Diablo 1? Recently some of my friends and I grew nostalgic about the original Diablo and realized we've never truly tried the multiplayer aspect of that game. So we set up a modern VPN LAN solution via tuungle (using the appropriate IPX Wrappers) but the problem is, while any of us can manage to create session in Diablo FULL, others cannot find a way to join my IPX/LAN game.  There are no "join" buttons in the game itself.  I've read somewhere that Spawn version is a trial version but can be used to join Multiplayer games. If they can, is it possible for them to play the entire game on LAN or is trial restricted from choosing some classes/accessing some areas?  Or are there some other ways to join? How to detect scene strips in the VSE on frame changes? I need to detect scene strips in the VSE on the current frame, meaning on what strip is the play head at this moment? However I can't seem to find the right type(?) to attach the ".strip_elem_from_frame" function to, in order to get the info/name/type on the strip. Here's a test script which must run in a screen with a sequencer with scene and movie strips in it:  import bpy  #update at frame change def currentStrip(*pArgs):     print("Current Strip: "+str(bpy.context.sequences[0].strip_elem_from_frame(bpy.context.scene.frame_current))) #Doesn't detect any strips at all.  #add frame change handle def attachAsHandler():     for f in bpy.app.handlers.frame_change_pre:         bpy.app.handlers.frame_change_pre.remove(f)     bpy.app.handlers.frame_change_pre.append(currentStrip)  currentStrip() attachAsHandler() Is posting someone's comment as an answer okay? I came across  and at the time there were no suggested answers. After reading Mark Hubbart's comment (at the time with four upvotes), which was the correct answer, and seeing that it had been over 30 minutes since his comment, I figured I would provide that answer in my own words, which I did. My answer is longer, and I think more rounded and more useful, but the core of the answer came from the comment. I have no idea if I'd have thought up the answer on my own--a definite maybe to that.  Now had I tried to be "honorable" or something, such as instead of answering, suggesting to the commenter that he make his comment an answer, I would only have accomplished giving away easy rep to some other user not as into gratuitous self-denial.  The commenter had merely to enter his comment into an answer box instead of a comment box! It was his choice! Whether he was too lazy or didn't think his answer worthwhile or some other reason is not my responsibility. Must I bend over backward to help him earn points that he so carelessly left lying around for another person to take? It just took a tiny bit of non-laziness on my part to get my text typed into the box that would reward me instead of the box that wouldn't.  If my perspective is incorrect and the community would rather see such answers-as-comments rewarded and supported, I will gladly accept that. In the meantime, I just want to shake off the tiny bit of guilt my overly-nice and overly-concerned-with-propriety self is feeling. :) Finding the left and right cosets of H = {(1), (12), (34), (12) ○ (34)} in S4 I have an exercise where I am supposed to find the left and right cosets of H = {(1), (12), (34), (12) ○ (34)} in S4. But how do I generate the cosets? As I have understood it you are supposed to pick a number that is not in the set H and multiply it with every number in H. But this does not exactly give the right answer. I would really appreciate it if someone gave an easy to understand explanation of how to generate the left and right cosets. How do I enable hibernation on Wubi? I installed Ubuntu on my Windows 7 Sager laptop using Wubi. Hibernate (i.e. suspend to disc) is not an option from the power icon, only suspend, shutdown, etc. Hibernate is also not an option from my battery/lid close options. I understand that hibernation is disabled by default in Ubuntu 12.04. I tried running pm-hibernate but I get the following message:  Looking for splash system... none  s2disk: Snapshotting system   and then the computer just hangs with a black screen. According to the documentation  if this fails then I can't enable hibernate but it offers no help in making pm-hibernate succeed.  Could swap be my problem? It looks like I have very small swap:  user@ubuntu:~$ cat /proc/swaps Filename                Type        Size    Used    Priority /host/ubuntu/disks/swap.disk            file        262140  0   -1   The advice on  is only for the author's set up (e.g. I don't have an Ubuntu install disk since I used Wubi) and he says that 'INFO: This will not work for 12.04, resume from hibernate work differently in 12.04.'  Any advice? I really need to get hibernate working to use my laptop as a, er, laptop.  Thanks Do I have to care about bad boxes? When I compile my PDF from LaTeX source, do I have to care about all the messages (currently 28) about 'bad boxes'?  The PDF seems fine to me. Design review - RGB LED color mixer using PWM Can I run OSX applications? Just wondering, are there any projects like WINE, but for Mac software? That is, can we use a program that acts like a compatibility layer to run Mac apps? Is AES in CBC mode secure if a known and/or fixed IV is used? I have a need to encrypt credentials for a third-party app used by a secured internal app. Over on ITSec.SE, I was helpfully shown a scheme to encrypt the third-party credentials based on a hash of the credentials for the internal app.   I picked AES as the encryption algorithm, but the problem is that the password-based scheme doesn't produce a "secret" IV. So, the IV must at least be known to an attacker (stored alongside the encrypted data). A hash value used for password verification could work, or I could just generate a pseudorandom byte array and drop it in the DB as a new column. I was further considering, for simplicity, to use a constant IV.   What adverse effect will either of these choices have on the security of the encryption? Does AES depend, as many block ciphers do, on an unpredictable IV? Does it matter if the IV is stored as unencrypted plaintext? Measure of Image of Linear Map I am trying to work my way through the proof of the change of variables theorem for Lebesgue integrals. A key lemma in this context is as follows:  If $T:\mathbb{R}^n \rightarrow \mathbb{R}^n$ is a linear map and $A \subset \mathbb{R}^n$ is Lebesgue measurable then $\lambda(T(A)) = |\det T \  | \cdot \lambda (A)$, where $\lambda(X)$ denotes the Lebesgue measure of $X$.  Can anyone provide a reference for a proof of this lemma that clearly references the facts from linear algebra that are necessary to effect the proof? The source I have for this lemma refers to German texts that I am incapable of reading and I have been unsuccessful at finding an alternate proof.  Added For the Benefit of Future Readers: In addition to the excellent references I received in response to this question, I have managed to find an additional reference that also provides a good proof of this fact: Aliprantis and Burkinshaw's Principles of Real Analysis, Third Edition, Lemma 40.4 pp 389-390. I have a bunch of external and internal HDDs that I use on a Linux system. I only have Linux systems, so using a Linux file-system would only make sense, right? However I'm currently using NTFS everywhere, because it gives me the most usable space out of HDDs.  I would like to switch to Linux file-systems now though, mostly because of permissions and compability (e.g. I can't get my LUKS encrypted NTFS partition to resize under Linux, keeps telling me to chkdsk under Windows).  However when I formatted those HDDs I tried out a bunch of different filesystems and every Linux filesystem, even ext2 which as far as I know has no journaling, used a lot of space for itself. I don't recall exact values, but it was over 100GB that NTFS got me more on a 2TB HDD, which is a lot.  So my question is: Is there a way to make ext-filesystems use less space for themselves? Or is there another filesystem (I've tried ext2, ext3, ext4, NTFS and vfat - None of them came even close to the usable space NTFS offered me) with perfect Linux support and great usable space?  I'd love to hear about how and why filesystems (especially ext2 which has no journaling) use that much more space than NTFS and I don't know where else to ask. I'd mostly prefer a way to use ext4 without journaling and anything else that uses up this much space, if that's possible. When $f(x+1)-f(x)=f'(x)$, what are the solutions for $f(x)$?