If there was no time prior to the big bang and it was possible that it expanded and created the universe (and it happened) then, despite time doesn't exist there, if something is possible it will happen?
I saw  hosted by Stephen Hawkins.  And if I didn't get it wrong, it says that there was no time before the big bang, time was created there.  So how can anything happen when there is no time (eg: the creation of time and the universe)? Is this what he calls a 'singularity'? Which I could think like this: when there is no time nothing can happen, except during this singularity.  Of course I don't know of a law that says 'when there is no time nothing can happen..', I just came up with it, as something intuitive.
How to tell the difference between linear and non-linear regression models? I was reading the following link on non linear regression . My understanding from reading the first section "Nonlinear Regression vs. Linear Regression" was that the equation below is actually a linear regression, is that correct? If so why?  $$y = b_1x^3 + b_2x^2 + b_3x + c$$  Am I also to understand that in non linear regression multicollinearity isn't an issue? I know that multicollinearity can be an issue in linear regression so surely if the model above is in fact a linear regression there would be multicollinearity? How hard do early-career academics in the United States work, really? I'm finishing a PhD in Sweden this year and seeking a post-doc in the United States (atmospheric remote sensing).  It is clear that a job in academia is not a nine to five job; nor do I want it to be.  I often work late in the evening when I'm on a productive spur.  When an important dead-line is coming up, one needs to work harder, and there is no overtime paid.  I accept that.  However, no matter how much I'm interested in my research, I do enjoy and need a reasonable amount of spare time, too; relaxing on the weekends, occasionally a long weekend away, and sometimes a longer trip, such as three weeks in the wilderness.  Regarding the normal work ethos for early-career academics in the United States, I have a hard time judging what is normal and what is excessive.  Some examples:    warning post-docs that he expects all of the members of the group to work evenings and weekends. My apparent naïveté in believing that , despite Wikipedia  as a rest from work, or a hiatus, often lasting from two months to a year.  I was thinking of my friend, who spent a year between his PhD and his first post-doc travelling from France to Mongolia mostly on foot. Someone  I am not a good role model, but when I don't work on a Sunday, I count that as a vacation day.  having no employment-related benefits such as paid vacations, sick leave, or unemployment compensation. Question    We don't have such a work-ethos where I'm at.  I belief that working too hard risks stress and burn-out, and does not increase productivity in the long run, nor human well-being.  I want to do science.  Doing science makes me happy, but having time to relax while not doing science is important for me.  Does the selection of examples I gave above represent a normal situation in U.S. early-career academia?  Should I expect an attitude where asking for a 3-week holiday during the summer is considered as being not serious, or is the situation in practice usually not as bad as the examples above make it sound?  How hard to early-career academics in the United States work, really? Displaying page construction guides Is there any way to overlay some lines and dimensions on the document so that one can see where the margins end and more easily examine the overall layout and ratios of elements on the page?  See for example, some of the illustrations of frameworks in this article on the  and this one on  (which displays dimensions). Adapt Ubuntu to a high-DPI resolution screen How can I adapt Ubuntu to a high resolution display?  I have a display with 3200x1600px on only 11'' and everything looks really tiny. What does “a couple” mean to you, and what does “a few” mean to you? What does “a couple” mean to you, and what does “a few” mean to you?  Is there a proper way to use these words?  It was striking to hear that “a couple” meant two (2) to someone.  My reaction was, “how/why do you make a short word longer by adding an extra syllable to just say ‘two?’”  I think Few: 2-3, Couple 4-6, Several 7+.  What are your thoughts? I came to this conclusion: the primes that can't be written as the sum of two squares (lets use$p\prime$ to denote) can be written as ${p}\prime \equiv 3 \;(\bmod\; 4)$.  I need a simple proof to show this and am stuck. I would appreciate guidance! "export PS1=" for customizing shell prompt Is my paper under review (or similar) for too long and if yes, how should I react? I'm learning calculus, specifically derivatives and applications of MVT, and need help with the following exercice:      Show that, for all $n &gt; 1$ $$\frac{1}{n + 1} &lt; \log(1 + \frac1n) &lt; \frac1n.$$    I tried to follow the below steps in order to prove the RHS inequality:   Proving that $f &lt; g$ on $I$ from $a$ to $b$:  Step $1$. Prove that $f' &lt; g'$ on $\operatorname{Int}(I)$.  Step $2$. Show that $f(a) \leq g(a)$ or that $f(a^+) \leq g(a^+)$  Following the above steps, let $f(x) = \log(1 + \frac1x)$ and $g(x) = \frac1x$, for all $x &gt; 1$. One has  $$f'(x) =  -\frac{1}{x^2 + x} \quad \text{and} \quad g'(x) = -\frac{1}{x^2}.$$  We note that, for every $x &gt; 1$, $f'(x) &gt; g'(x)$. Moreover, $f(1^+) = \log(2) &lt; 1 = g(1^+).$   My problem is that I got the wrong inequality sign in Step $1$.    Looking at the solution in my textbook, the author suggests using the MVT but I don't know how to apply it in this case. Pending suggested edit message bug I just tried to edit a post on Stack Overflow but when I pressed the 'edit' button it showed me this message on a white page.    I know what the message means but I don't think it is supposed to show up in a white page. So, is this a bug or is it something else? I understand that the mechanics and design of a lightsaber aren't that complicated.  Do others besides the Jedi and Sith (or their minions) make or use lightsabers?  And if they don't, why not? Would it better the community if we got compensated for posts? Even with minuscule alt coins? If we are effectively generating more traffic to Stack Exchange sites, would it become a better community if users were compensated somehow besides rep points? Even with minuscule alt coins? Japan is a volcanically active country which means it has a plethora of onsen (hot springs) all around the country.  Visiting these onsen is supposed to be a popular vacation destination for the work-weary Japanese.    I've been told that, as with other things in Japan, there is a rather strict etiquette surrounding the use of the onsen.  In particular, the two things I've read about so far are   Swimming Suits are not allowed. It is very important that one bathe immediately before entering the onsen.   Are these true?  Are there any other taboos that a naive American should be aware of? table side by side with minipage I can't manage to get two tables side by side in a minipage environment. Any kind suggestion would be highly appreciated!   \documentclass{article} \usepackage{array}  \begin{document} \begin{table}[htbp] \centering \begin{minipage}{.2\textwidth}     \begin{tabular}{| m{3cm} | m{4.3cm} | c |}   \hline  number of entity filter (size 1) &amp; number of context filters (size 2, size 3,  size 4) &amp; Accuracy\\ [2ex]   \hline  32  &amp;  32  ,  32  ,  32  &amp;  0.835 \\[0.5ex] \hline 32  &amp;  64  ,  64  ,  64  &amp;  0.821 \\[0.5ex] \hline 32  &amp;  128  ,  128  ,  128  &amp;  0.819 \\[0.5ex] \hline 32  &amp;  256  ,  256  ,  256  &amp;  0.749 \\[0.5ex] \hline 32  &amp;  512  ,  512  ,  512  &amp;  0.683 \\[0.5ex] \hline 32  &amp;  1024  ,  1024  ,  1024  &amp;  0.528 \\[0.5ex] \hline 32  &amp;  2048  ,  2048  ,  2048  &amp;  0.235 \\[0.5ex] \hline 64  &amp;  32  ,  32  ,  32  &amp;  0.850 \\[0.5ex] \hline 64  &amp;  64  ,  64  ,  64  &amp;  0.816 \\[0.5ex] \hline 64  &amp;  128  ,  128  ,  128  &amp;  0.786 \\[0.5ex] \hline 64  &amp;  256  ,  256  ,  256  &amp;  0.795 \\[0.5ex] \hline 64  &amp;  512  ,  512  ,  512  &amp;  0.765 \\[0.5ex] \hline 64  &amp;  1024  ,  1024  ,  1024  &amp;  0.669 \\[0.5ex] \hline 64  &amp;  2048  ,  2048  ,  2048  &amp;  0.331 \\[0.5ex] \hline 128  &amp;  32  ,  32  ,  32  &amp;  0.920 \\[0.5ex] \hline 128  &amp;  64  ,  64  ,  64  &amp;  0.890 \\[0.5ex] \hline 128  &amp;  128  ,  128  ,  128  &amp;  0.886 \\[0.5ex] \hline 128  &amp;  256  ,  256  ,  256  &amp;  0.846 \\[0.5ex] \hline 128  &amp;  512  ,  512  ,  512  &amp;  0.789 \\[0.5ex] \hline 128  &amp;  1024  ,  1024  ,  1024  &amp;  0.755 \\[0.5ex] \hline 128  &amp;  2048  ,  2048  ,  2048  &amp;  0.488 \\[0.5ex] \hline 256  &amp;  32  ,  32  ,  32  &amp;  0.920 \\[0.5ex] \hline 256  &amp;  64  ,  64  ,  64  &amp;  0.922 \\[0.5ex] \hline 256  &amp;  128  ,  128  ,  128  &amp;  0.912 \\[0.5ex] \hline 256  &amp;  256  ,  256  ,  256  &amp;  0.877 \\[0.5ex] \hline 256  &amp;  512  ,  512  ,  512  &amp;  0.872 \\[0.5ex] \hline 256  &amp;  1024  ,  1024  ,  1024  &amp;  0.771 \\[0.5ex] \hline 256  &amp;  2048  ,  2048  ,  2048  &amp;  0.683 \\[0.5ex]  \hline  \end{tabular} \end{minipage}% \hfill \begin{minipage}{.2\textwidth}     \begin{tabular}{| m{3cm} | m{4.3cm} | c |}   \hline  number of entity filter (size 1) &amp; number of context filters (size 2, size 3,  size4) &amp; Accuracy\\ [2ex]   \hline 512  &amp;  32  ,  32  ,  32  &amp;  0.910 \\[0.5ex] \hline 512  &amp;  64  ,  64  ,  64  &amp;  0.922 \\[0.5ex] \hline 512  &amp;  128  ,  128  ,  128  &amp;  0.909 \\[0.5ex] \hline 512  &amp;  256  ,  256  ,  256  &amp;  0.910 \\[0.5ex] \hline 512  &amp;  512  ,  512  ,  512  &amp;  0.883 \\[0.5ex] \hline 512  &amp;  1024  ,  1024  ,  1024  &amp;  0.730 \\[0.5ex] \hline 512  &amp;  2048  ,  2048  ,  2048  &amp;  0.682 \\[0.5ex] \hline 1024  &amp;  32  ,  32  ,  32  &amp;  0.925 \\[0.5ex] \hline 1024  &amp;  64  ,  64  ,  64  &amp;  0.931 \\[0.5ex] \hline 1024  &amp;  128  ,  128  ,  128  &amp;  0.920 \\[0.5ex] \hline 1024  &amp;  256  ,  256  ,  256  &amp;  0.917 \\[0.5ex] \hline 1024  &amp;  512  ,  512  ,  512  &amp;  0.899 \\[0.5ex] \hline 1024  &amp;  1024  ,  1024  ,  1024  &amp;  0.858 \\[0.5ex] \hline 1024  &amp;  2048  ,  2048  ,  2048  &amp;  0.776 \\[0.5ex] \hline 2048  &amp;  32  ,  32  ,  32  &amp;  0.933 \\[0.5ex] \hline 2048  &amp;  64  ,  64  ,  64  &amp;  0.934 \\[0.5ex] \hline 2048  &amp;  128  ,  128  ,  128  &amp;  0.925 \\[0.5ex] \hline 2048  &amp;  256  ,  256  ,  256  &amp;  0.928 \\[0.5ex] \hline 2048  &amp;  512  ,  512  ,  512  &amp;  0.907 \\[0.5ex] \hline 2048  &amp;  1024  ,  1024  ,  1024  &amp;  0.878 \\[0.5ex] \hline 2048  &amp;  2048  ,  2048  ,  2048  &amp;  0.798 \\[0.5ex]  \hline  \hline \end{tabular} \end{minipage} \caption{filter window size} \label{tab:config_filternum} \end{table}   \end{document}   What I have so far  EDIT: I followed the second solution from , and it somehow didn't work. I am not sure why. What is the purpose of -e in sed command? I can't find any documentation about the sed -e switch, for simple replace, do I need it?  e.g.  sed 's/foo/bar/'   VS  sed -e 's/foo/bar/' What's the best way to animate an illustration for the web? I have a couple of illustrations done in Illustrator and I am planing to animate it for a website that I am working on, I've heard of  toolkit with flash, but is it the best way to go or is there another "better" way of doing it?  Here's an example of the kind of animations I am aiming for: Can a hotel kick you out if you let an unregistered guest share a room with you? Is it possible to load a TikZ library locally? I'm writing a set of course notes that has an appendix containing many activities.   I do not wish the activities to be shown in the Table of Contents, but I do wish them to be numbered. Here is the solution I was using:  In the preamble:  \newcommand{\activity}[2]{\bgroup\let\addcontentsline=\nocontentsline#1{#2}\egroup}   and now my "activity" starts out with:  \newpage \activity\section{A Fun Educational Activity}   There is only one problem. The activity starts out indented, as opposed to not indented, as a section should be.   How do I make my activity start out without an indent?  I realize I could simply add \noindent but it seems to me that there should be a more elegant solution. Chrome asks for password to unlock keyring on startup In Google Chrome, when I go to a login page, a window pops up asking to "Enter password for keyring 'default' to unlock". In most cases, whether I click Cancel or enter my password, the login form gets auto filled anyway.  How do I get rid of the popup? I want it to auto login each time, not ask for my system password. The dialog box never appears for any other apps.