Toilet paper, paper towels or cardboard are all relatively strong when dry but as soon as they are wet it is much easier to tear them. Why is this?
My four-year-old daughter asked me why paper tends to fall apart when wet, and I wasn't sure.  I speculated that the water lubricates the paper fibers so that they can untangle and separate more easily, but I really wasn't sure.
What is the correct way to install proprietary ATI Catalyst Video Drivers (fglrx) directly from AMD? I am planning on doing a fresh install of Ubuntu and want to know what is the correct way to install ATI Catalyst Video Driver?      There are multiple valid answers for this question spanning over several versions of Ubuntu. For your convenience an index of each below: Are numbers in which all substrings are primes finite regardless of base? I read the definition of  as  $$W ~=~ \vec{F} \cdot \vec{d}$$  $$\text{ Work  =  (Force) $\cdot$ (Distance)}.$$ If a book is there on the table, no work is done as no distance is covered. If I hold up a book in my hand and my arm is stretched, if no work is being done, where is my energy going? I'm a bit familarized with conditional sentences. But the following sentences with 'should' and 'happen to' are quite confusing too me. They are:   If it should rain, I will stay at home. 2.If it should happen to rain, I'll stay at home   If it happens to rain, I'll stay at home.    What are the meaings of those sentences ? Do they all mean the same ? Thank you a lot in Advance for your answer. Why do you write "occurred" but "listened"? The past tense of to occur is occurred (not occured), but the past tense of to listen is listened (not listenned).  Why? What is the general rule that is applied to make the past tense of a verb? Can't boot Ubuntu or Windows 8 after Ubuntu 64-bit install on Samsung series 7 Windows 8 laptop, error "All boot options are tried." I have a Samsung Chronos 7 laptop (NP770Z5E) pre-installed with Windows 8, and I wanted to install Ubuntu 13.04 alongside it, so I can dual boot. Here is what I've done:  Updated BIOS to lastest version (P04ABU) using Samsung Updater Reduced Win8 partition by half, I left the others untouched Created a bootable USB stick using  and a Ubuntu 13.04 64-bit image Disabled FastStartup on Win 8 Disabled Fast BIOS Mode Boot Mode changed to CSM OS  Update:  Also disabled Secure Boot (I had to disable it in order to select CSM OS)  After that I saved the BIOS settings, and shut down the computer. I plugged in the USB drive, powered the computer on, entered the BIOS and tried to change the boot order. Oddly, there was only one option in the boot order screen, the USB drive (HDD didn't show up in the boot priority screen). I ignored that and installed Ubuntu. I've created 3 partitions from the unused spaced left: a 8GB swap, a 100MB BIOS boot partition, and the rest to ext4, mounted in /. Boot loader installed on /sda. After a reboot, this message appears:  All boot options are tried. Press &lt;F4&gt; key to recover with factory image using Recovery or any other keys for next boot loop iteration.  So I went to the BIOS to change the boot device priority, and the list is empty! Enabling Secure Boot and Fast BIOS had no effect. I used the Ubuntu Live USB to check the disk contents, I can see the Ubuntu and Win 8 partitions. I've used Boot Repair (using the Recommended Repair), with no avail, the Boot Repair log is here:  Boot Repair showed me a message about the system being a&quot;EFI system&quot;. I suppose that means that I should have checked out the advanced settings. I don't know how to proceed. I don't know if it's a good idea to &quot;recover with factory image&quot; since I have modified the original partitions. Maybe I need to experiment with Boot Repair's advanced settings. Why does turning Caps Lock off take such a long time to work? This is my biggest issue with Linux and the main reason I don't use it as my main working OS.  Whenever I use caps lock to write something in upper case and disable it in order to keep writing the next letter AFTER I've disabled it is written in upper case.  So, my text comes out weird, as SOMETHING *L*ike this  I've tried Linux Mint, Fedora ... and the issue keeps happening.  Searching Google I've found some very rare persons have the same issue, but I was unable to find any solution.  Is there any way to solve this or am I DOOMED *F*or life?  BTW, whenever I ask this question someone suggest I should learn to use shift, instead of caps lock. I know, that's the right way, but I'm used to use caps lock and, well, it should work. Show community wikis differently in the Android app What is the first reference in Sci-Fi to a touch-screen computer interface? I know in TNG that all computer interfaces are now touch-screen, and that got me thinking: when was the first reference to touch-screen computer interfaces in Sci-Fi made? I want to be able to calculate the confidence interval from the estimated coefficient and respective standard errors.  I have a linear regression model which can be summarized (in R):  summary(fit1)  Call: lm(formula = bwt ~ height + weight + parity, data = data)  Residuals:     Min      1Q  Median      3Q     Max  -66.913 -10.624   0.991  10.979  55.621   Coefficients:             Estimate Std. Error t value Pr(&gt;|t|)     (Intercept) 31.19217   13.56879   2.299   0.0217 *   height       1.24964    0.23083   5.414 7.48e-08 *** weight       0.06781    0.02823   2.402   0.0164 *   parity1     -1.83309    1.19838  -1.530   0.1264     --- Signif. codes:  0 ‘***’ 0.001 ‘**’ 0.01 ‘*’ 0.05 ‘.’ 0.1 ‘ ’ 1  Residual standard error: 17.9 on 1170 degrees of freedom Multiple R-squared:  0.04898,   Adjusted R-squared:  0.04654  F-statistic: 20.08 on 3 and 1170 DF,  p-value: 1.071e-12   With this model I can calculate the respective confidence intervals:  &gt; confint(fit1)                   2.5 %     97.5 % (Intercept)  4.57029503 57.8140351 height       0.79676227  1.7025207 weight       0.01243198  0.1231932 parity1     -4.18429933  0.5181151   I would expect the intervals of the predictor height to be given by  $$ 1.24964 \pm (1.96*0.23083) = [0.7972132,1.702067] $$  where 1.24964 is the estimated value for the coefficient and 0.23083 is the standard error for this coefficient. The numbers are close but not quite the same.  What am I doing wrong? SQL Server Agent Jobs and Availability Groups I'm looking for best practice in dealing with scheduled SQL Server Agent jobs in SQL Server 2012 availability groups. Maybe I missed something, however at the current state I feel that SQL Server Agent is not really integrated with this great SQL2012 feature.  How can I make a scheduled SQL agent job aware of a node switch?  For example I have a job running on the primary node which loads data each hour. Now if the primary goes down, how can I activate the job on the secondary which now becomes primary?   If I schedule the job always on the secondary it fails because then the secondary is read-only. How should different sized RAM be added to iMac? I have a mid-2011 iMac which came with 4GB RAM (2x2GB). I just bought 8 GB (2x4GB) and added it to get a total of 12GB. The current configuration is as follows:    Given that the RAM is a different size, do I have the optimal locations for the different RAM chips? At the moment what I did was to simply add the 2 new sticks of RAM in the two empty slots. I just installed Ubuntu 16.10 on my desktop and have a USB deathadder. The problem is I can't see where the cursor actually is because it appears only in the top left of my screen. The mouse still moves but the cursor graphic doesn't follow Qualcomm Atheros QCA6174 802.11ac Wireless Network Adapter [168c:003e] (rev 32) can't enable wi-fi Quote unquote (or end-quote), unseparated by the actual quotation In spoken English, people often say "quote-unquote" (or "quote-endquote") to indicate that part of what they are saying is a quotation (scare or otherwise). Sometimes the quoted material will go between quote and unquote, and occasionaly it will precede the quote-unquote. Often, though, "quote unquote" introduces the quoted material.  Why does quote unquote precede the quotation?  It would seem that quote opens the quoted text and that unquote closes it, but then why would we close the quotation before actually providing it. It would be the equivalent of writing your quotation marks together, "", rather than around the quoted text.  What are the origins of this construction?  Three years ago ChrisR asked  on whether it is correct to use quote, unquote. The answers did not deal with origins, but one commenter suggested that quote-unquote is a corruption of quote-on-quote, but he provided no evidence, nor any real explanation. I have a quaternion, coming from a system with the following:(intertial sensor)  Right handed. Forward direction: Y axis Right direction: X axis Up direction: Z axis   I need to convert this into a coordinate system that is: (Unreal engine)  left-handed. Forward direction: X axis Right direction: Y axis Up direction: Z axis   I have tried negating the axis, and angle, I have tried switching values, i cannot get this to work. All help greatly appreciated! I am working in C#, with Microsoft.Xna.Quaternion. Is there any way to accept only numeric values in a JTextField? Conjugate class in the dihedral group List all the conjugate classes in the dihedral group of order $2n$ and verify the class equation.  The dihedral group is generated by two elements $r$ and $s$.   The order of $r$ is two since $r^2=e$ and $s$ is $n$ since $s^n = e$. And I know all elements can be produced as either $s^k$ or $rs^k$. How can I list all the conjugacy class? How to build a custom kernel? Is a 1st-level spell cast using a 4th-level slot a 1st-level spell, or a 4th-level spell?