Having trouble playing DVDs on my laptop. They are .vob files. Neither VLC, Mplayer nor SMPlayer seem to help. Anything else I could do?
I just downloaded a DVD which is for a movie. After uncompressing the DVD file I see .VOB, .IFO and .BUP files. If I open the first .VOB file it shows me the DVD menu but I can't interact with it. So, my question is... is Totem able to play those kind of files? If so, how can I achieve that? What other app could I use in order to reproduce those files?  Edit  Using VLC didn't work neither. I forgot to mention I have already tried that. Let me rephrase: if I open the first video file it shows the DVD menu, BUT I can't interact with it.
Squares in arithmetic progression It is easy to find 3 squares (of integers) in arithmetic progression. For example, $1^2,5^2,7^2$.  I've been told Fermat proved that there are no progressions of length 4 in the squares. Do you know of a proof of this result?   (Additionally, are there similar results for cubes, 4th powers, etc? If so, what would be a good reference for this type of material?)    Edit, March 30, 2012: The following  in MO is related and may be useful to people interested in the question I posted here. I have a WordPress site which is 90% based on images.  I've installed Wp-Super-Cache, now it seems to load a little bit faster.   I've made a speed test on Pingdom Tools:   Page size 4.7MB Load time 5.09s Requests 153 Perf. grade 74/100   And also the Time Spent per Content Type:   Image    88.23%     So the problem is obviously the images.   My plan is to try as much as I can to optimize the images in terms of size, and then to add CDN support.  Is this enough in terms of improving the loading of images? Daily reputation cap doesn't account for reputation * loss* due to bounty awarded? There are many Q&amp;A's around this and the best explanation of daily cap model is from this answer that uses . It is an old answer but gives a good understanding.   My confusion is in applying this model to my situation yesterday.    On 31/12/2019, I awarded a bounty to , since it became eligible for bounty (2 days after posting it). Subsequently, I got more upvotes (including one accept) which exceeded the daily cap of 200. I am confused about this-loss of reputation due to bounty awarded by me preceeded subsequent gain of reputation so going by the bucket analogy, I should have my rep adjusted accordingly and those 6 up votes (at the bottom of table) should have been credited (rep should have been 177 instead of 117),  /reputation shows this   2 219845 (10)  1 219884 (2)  2 170717 (10)  2 219621 (10)  2 219845 (10) 2 219845 (10) 2 218537 (10)  2 219845 (10)  2 219892 (10)  2 219845 (10) 8 219821 (-100)  2 219845 (10)  2 219621 (10)  2 219845 (10)  2 219821 (10)  2 219845 (10)  2 219845 (10)  2 219845 (10)  2 219912 (10)  1 219912 (15)  2 219845 (10)  2 219845 (10)  2 219892 [10]  2 219845 [0]  2 219621 [0]  2 219845 [0]  2 219845 [0]  2 219845 [0]  2 219845 [0]  -- 2019-12-31 rep +117 = 27089 --   It is not the 6 votes I am bothered about, it is more about trying to correct my understanding  or have I stumbled upon an anomaly? How can I show that the set of rational numbers with denominator a power of two form a dense subset of the reals? How can I show that the set of rational numbers with denominator a power of two form a dense subset of the reals? Why do 'get' and 'have' work similarly in      I got/had my car repaired.    but differently – that is are not complemented in the same way although they still mean the same – in      I got someone to repair my car.    and      I had someone repair my car. Effect of switching response and explanatory variable in simple linear regression Let's say that there exists some "true" relationship between $y$ and $x$ such that $y = ax + b + \epsilon$, where $a$ and $b$ are constants and $\epsilon$ is i.i.d normal noise. When I randomly generate data from that R code: x &lt;- 1:100; y &lt;- ax + b + rnorm(length(x)) and then fit a model like y ~ x, I obviously get reasonably good estimates for $a$ and $b$.  If I switch the role of the variables as in (x ~ y), however, and then rewrite the result for $y$ to be a function of $x$, the resulting slope is always steeper (either more negative or more positive) than that estimated by the y ~ x regression. I'm trying to understand exactly why that is and would appreciate it if anyone could give me an intuition as to what's going on there. Using setminus notation with set elements The "correct" way to write a set without a specific element is as follows: $S \setminus \{s\}$  But in some contexts this is cumbersome to write/type or read, and it detracts from the flow of the writing. Is it acceptable to just use $S \setminus s$?  Edit: By "cumbersome" i mean they look bad when you're trying to inline formulas in LaTeX. Singular vs. Plural with Multiple Gerunds as Subject (IE: [Gerund] and [Gerund] are/is [something].) I'm trying to find out whether I should use a singular or plural verb when there are multiple gerunds as the subject of the sentence. For example:  Running the correct course and keeping a steady pace are/is necessary in order to win.  With either one of these by itself, &quot;is&quot; would be correct:  Running the correct course is necessary in order to win. Keeping a steady pace is necessary in  order to win.  With both gerunds combined, I can't seem to figure out whether the verb should stay singular since each phrase is singular, or if it should become plural since there are two connected by &quot;and&quot;. If we just treat the gerunds as regular nouns, then obviously it would become &quot;are&quot;, but I'm not sure if gerunds have the exact same rules as regular nouns. I know that if the sentence was:  Running the correct course and keeping a steady pace are both necessary.  That &quot;are&quot; would be correct, but without the &quot;both&quot; it sounds incorrect to me. Does anyone know the official rule here? How precisely do I need to post close to 7:00 (somewhere) to get hero of time? Timezones... are complicated. We have full hour offsets, half hour offsets...  And time keeping isn't always accurate. So does the Hero Of Time hat assume full or half hour offsets (or literally any timezone) and how close to 7:00 at somewhere do I have to post for my hat? i install ubuntu and followed a guide to put 20gb in '/' and the rest (150gb) in '/home'. Now i just found out that a lot of the things installed in ubuntu usually goes to '/' instead of '/home'. I have a lot more things to install.  So what is the point of '/home' ? How do I fix this ? Should I transfer 150gb from '/home' to / ?  Filesystem      Size  Used Avail Use% Mounted on udev            7.8G     0  7.8G   0% /dev tmpfs           1.6G  9.5M  1.6G   1% /run /dev/sda6        19G   16G  1.8G  91% / tmpfs           7.8G  676K  7.8G   1% /dev/shm tmpfs           5.0M  4.0K  5.0M   1% /run/lock tmpfs           7.8G     0  7.8G   0% /sys/fs/cgroup /dev/sda2        96M   29M   68M  31% /boot/efi /dev/sda8       159G  1.1G  150G   1% /home tmpfs           1.6G   56K  1.6G   1% /run/user/1000   what is /boot ? Its not '/' or '/home' $a\equiv\bar a\!\pmod{\!kn}\Rightarrow a\equiv\bar a\!\pmod{\! n};\ $ $(a\bmod kn)\bmod n=a\bmod n.\ $ Congruences persist mod factors of the modulus I noticed relation between modulo operation and number which is power of two  Example I have to calculate $ 3431242341 \mod 2^5 $, which is $ 5 $ but it is equivalent to  $ ( 3431242341 \mod 2^9 ) \mod 2^5 $   I tried many examples and it seems to be true in general, and I am not sure if it is a coincidence or true in general that I can use first modulo operation ( greater number) and the result will be the same. I might end up teaching philosophy in Finnish lukio/gymnasium. I will not get an opportunity to practice teaching it - I do get to practice teaching mathematics a fair deal, though. (The situation is somewhat unfortunate.) I have taken subject studies in philosophy at university. They amount to around 60 credits (ECTS).  Suppose I give the students an exam, which asks them to write an essay or two. After that my task is to grade the exams in a fair way and comment them in such a way that the students can learn from the feedback.  -  Suppose the task was to write an essay on the problem of universals - nominalism and realism, say. Let us say 6 points is the perfect score for this task.  I would expect the students to define nominalism and realism (2 points, maybe?) and explain the problem (2 points). Remaining two points for taking some stance and arguing for it - realism is more reasonable because so and so. Partial credits for demonstrating only partial understanding.  -  Am I missing some important aspects of philosophical thinking? Should I emphasize the different parts of an answer in a different way? I suspect my perspective is influenced by fairly extensive mathematics education - is there something particular I should watch out for? How can I install Celestia on Ubuntu 18.04.1? R/mgcv: Why do te() and ti() tensor products produce different surfaces? Why is the Ideal Norm Multiplicative? Renaming accessor/mutator methods in Eclipse? Is there any way to automatically rename accessor/mutator when a variable they get/set gets refactored -> renamed (Eclipse 3.4)? Master database is corrupt, instance won't start - what are my options? Help! My master database is corrupt, I can't even bring the SQL instance online! What are my options to get my server back up?   I do have a backup of master, but the  asks me to start the instance in single-user mode, which I can't do!  (Note: I'm leaving this question unspecified as to SQL version, so as to be a more widely-applicable reference. There are some similar questions on DBA.SE, but none that involve the server unable to start.) Simple Past vs. Present Perfect: "was" vs. "has been" Is it possible to build a single mysql query (without variables) to remove all records from the table, except latest N (sorted by id desc)?  Something like this, only it doesn't work :)  delete from table order by id ASC limit ((select count(*) from table ) - N)   Thanks. Do you think that "was going to be" or "would be" could be used as past tense of will?     I thought this book was going to be your choice.        I thought this book would be your choice.   Do these two sentences basically mean the same thing or are they slightly different?