My computer doesn't have a disc drive and I am unsure how to continue installing without one.
I tried to use the usb-creator.exe from Ubuntu 10.10 desktop i386 ISO image and it does create an USB stick that doesn't boot. When I try to boot from it I get:     Operating System not found.   I try to do this from Windows 7 x64. I'm not looking to create a live Ubuntu media, only an installation USB disk.  I repeated the process several times and I even tried to reformat the USB drive (FAT32), no success yet.  The USB stick is a 8GB one.
About 0.999... = 1 I've just happened to read this  on MO (that of course has been closed) and some of the answers to a similar  on MSE.   I know almost nothing of nonstandard analysis and was asking myself if something like the sentence « $1- 0.999 \dots$ is a nonzero positive infinitesimal» could be easily expressed and proved in nonstandard analysis.  First of all, what is 0.999... ? If we take the usual definition as a series or as a limit of a sequence of rationals, then it will still be a real number and equal to $1$ (I guess by "transfer principle", but please correct me if I'm wrong).  Instead, let's define  $$0.9_N:=\sum_{i=1}^N 9\cdot 10^{-i} $$  where $N\in{}^*\mathbb{N}\setminus\mathbb{N}$ is an infinite nonstandard natural number. This $0.9_N$ is a legitimate element of ${}^*\mathbb{R}$, expressed as $0.$ followed by an infinite number of "$9$" digits.  What can be said about $\epsilon_N:=1-0.9_N$ ? Is there an elementary proof that $\epsilon_N$ is a positive infinitesimal of ${}^*\mathbb{R}$ ? (by "elementary" I mean just order and field axioms and the intuitive facts about infinitesimals, like that for $x$ infinite $1/x$ is infinitesimal etc.; no nonprincipal ultrafilters &amp; C). TestMethod do not support Web service callouts, test skipped I have written a test class for a trigger on the lead object.  When i run the test class i get the following error:  Methods defined as TestMethod do not support Web service callouts, test skipped  There is an other trigger on lead that has a call to a webservice so i get this error.  I have wrapped the call with:  if (!Test.isRunningTest()) {    // do callout }   But i’m still getting the same error.  Any other way to run correctly the test class?  Thank you in advantage. How to solve $\frac 1{1.2.3}+\frac 1{2.3.4}+\frac 1{3.4.5}+...$ As my question says,   $$\frac 1{1.2.3}+\frac 1{2.3.4}+\frac 1{3.4.5}+...$$  As far as $\frac 1{1.2}+\frac 1{2.3}+\frac 1{3.4}+...$ is concerned, we can write it as $\frac 1{n-1} - \frac 1{n}$ What can we do here? How do you return to the default view (the one you see when blender starts)? Is it possible to have a pair of Gaussian random variables for which the joint distribution is not Gaussian? Somebody asked me this question in a job interview and I replied that their joint distribution is always Gaussian. I thought that I can always write a bivariate Gaussian with their means and variance and covariances. I am wondering if there can be a case for which the joint probability of two Gaussians is not Gaussian? Is it possible for many domain names to share one IP address? Is it possible for many domain names to share one IP address? For example, www.xjtl.com, www.fmie.com, sdmfl.com, etc.  Hundreds of domain names share just one IP – when you do a DNS query for each of them, the same IP is returned.  Are there any laws or Internet rules that disallow this? I installed Ubuntu today and since the first start up I have a problem with the mouse cursor.  It starts randomly disappearing and flickering a lot.  I have searched for a solution on Google and here but didn't find anything. Change color of links created with \in, \at, etc Assume you are given two objects whose exact locations are unknown, but are distributed according to normal distributions with known parameters (e.g. $a \sim N(m, s)$ and $b \sim N(v, t))$. We can assume these are both bivariate normals, such that the positions are described by a distribution over $(x,y)$ coordinates (i.e. $m$ and $v$ are vectors containing the expected $(x,y)$ coordinates for $a$ and $b$ respectively). We will also assume the objects are independent.  Does anyone know if the distribution of the squared Euclidean distance between these two objects is a known parametric distribution? Or how to derive the PDF / CDF for this function analytically? How to compute rational or integer points on elliptic curves This is an attempt to get someone to write a canonical answer, as discussed in this . We often have people come to us asking for solutions to a diophantine equation which, after some clever manipulation, can be turned into finding rational or integer points on an elliptic curve. See , , , , . (This list is biased towards questions I have answered because I remember them best; other people have answered such questions as well.) I would like an answer to which, after one of us has explained the cleverness, we could direct the OP.  An ideal answer would address    How to find both rational and integer solutions Good software solutions. Ideally, it would nice to have a walkthrough for doing these things with , so that people could find solutions without even installing anything. References for how to transform some standard presentations of elliptic curves into Weierstrass form, so that we don't have to write out the algebra every time. I'm thinking of  a cubic in $\mathbb{P}^2$ with a rational point that is not a flex,  $y^2 = \mbox{degree 4 polynomial}$, a $(1,1)$ curve on $\mathbb{P}^1 \times \mathbb{P}^1$, or an intersection of two quadrics in $\mathbb{P}^3$. This is my circuit. I need to find the power dissipated by Vlamp. So the lamp turns on if the Vlamp is more than 2V. When the lamp is on it has an internal resistance of 10 Ohms, and when it is off it acts like an open circuit.  How would I find the power dissipated? I know how to do it for Voltage sources and Resistors, but not elements like these.  One more thing, I already figured out that: Battery has open circuit voltage of 4V R1 = 5 Ohms R2 = 5 Ohms k = 0.2A/V When lamp on and Vlamp = 2V, Rbat = 10 Ohms   . Why is there such variation in PhD length internationally? I'm an undergrad in Australia, and at this stage I want to go on to do further study in maths (or maybe physics/CS, still have a few years till then).  Should I do so, I imagine that I will want to complete a PhD overseas. Possibly at a university in the US or maybe Oxbridge in the UK.  In Australia, PhDs typically take 3 or 4 years, and I would be eligible to go straight into a PhD upon completion of my undergraduate degree (it is research focused and includes an honours year, see ).  But, much of what I have found for overseas institutions has been in the range of 5-7 years, or maybe a 3-4 year PhD with a few years doing a master's degree beforehand.  Does this indicate that the level of rigour and amount of work produced is significantly different for various PhD programs, or is it the case that some programs are more relaxed and simply spread the same amount of work over a longer period of time? How do I enter a file or directory with special characters in its name? Shutdown and User button missing in panel Why is charge of the electron negative? "Looking forward to hearing from you" - May I omit "I am" at the beginning? The hidden flaw in "singular they"—what to do about reflexive pronouns? We have  to a question about gender-neutral pronouns, in which he points to the "singular they" and its long history of use in English. (Note that he also advises against using it.) Example:     If someone wants to watch TV tonight, they'll have to do the dishes.   This avoids having to say "he or she" in mixed-gender situations. Okay, fine. I'm not going to get my panties in a bunch if people want to talk this way.  But it occurrs to me that "singular they"—infelicitous at the best of times—really falls apart when extended into the realm of reflexive pronouns:     If someone wants to watch TV tonight, they'll have to do the dishes all by themselves. [?]   That feels very wrong. The only alternative, if one paints oneself into that corner, is to flip it back to singular:     If someone wants to watch TV tonight, they'll have to do the dishes all by themself. [???]   That feels worse.  If I'm to state this as a question, I guess I would put it thus: How can use of a "singular they" truly be reconciled? Is it really as much of a linguistic dead end as it feels to me? How to change SQL Server collation Database files that are built using SQL 2008 are not compatable with 2005. Is there a work around? How did Bill and Percy get 12 OWLs? In Prisoner of Azkaban, Hermione took 12 subjects, and needed a Time-Turner to do so. However, it is mentioned in the series that both Bill and Percy Weasley got 12 OWLs, so would have taken 12 subjects as well, so both would have needed Time-Turners for three years to do this. Doesn't this seem a little unusual, given how strict the Ministry is over the use of Time-Turners,  that they would give them to several Hogwarts students?