Why is the Ubuntu kernel (4.1.5) so far behind the current Linux Kernel (5.2.6, soon to be 5.3)?  I would love to use Ubuntu, but my development work depends on solid kernel code.
Why are packages in the official Ubuntu repositories older than the latest (upstream) versions from Debian Sid, PPAs, the authors, etc.?
How to remove shutdown option in start menu of Windows 10 I have a PC that should always be on. I recently upgraded to Windows 10 from Windows 7. In Windows 7 I changed the default action of the power button in the start menu to log off from my machine so that I could not accidentally shut it off. However in Windows 10 the start menu changed and this doesn't appear to be possible anymore?   I wonder how the shutdown option can be removed from the start menu. I cannot find any information about it but I expect this to be possible. Undocumented increase in minimum bounty value? I recently discovered that if I have posted an answer to a question, the minimum bounty I can offer for that question is +100 (instead of the usual +50).   Temporarily deleting the answer reinstates the +50 bounty (a workaround!).  As far as I can tell, this is not mentioned in  , , or . I've also tried  but didn't get very far.  So:   Should the FAQs be updated to include this information? Why have this rule in the first place if it's so easily bypassed?     Update:  This is indeed a new feature (introduced in ) to .This is mentioned explicitly in a few   but, as far as I can tell, not in FAQs. This information is therefore out of reach of mere mortals who do not have a finger on the pulse of MSO/SE.   The loophole mentioned above , but as of this update, can still be exploited (tested on superuser).  We can haz bugfix and faq update, pliz? Referencing bib files with spaces in the filename Python metaheuristic packages Make Javascript do List Comprehension WiFi not working Kubuntu 20.04 - Intel 8265 Network Interface Is there an easy way to put a box around a theorem in LaTeX? For example to state an important theorem. I tried using page 20 of the ntheorem , but I do not know how to use the package. Why does triply periodic univariate function not exist? A univariate function $f$ is periodic with period $p_1,\ldots,p_k$ if   $$f(z) = f(z + \sum_{i=1}^k n_i \cdot p_i)$$   for all complex $z$ and integers $n_i$. Elliptic function is an example of doubly periodic function.  that a triply periodic univariate function cannot exist, but why? Can't we follow the construction of elliptic functions that uses Schwarz-Christoffel formula to map upper-plane onto a triangle, and use the reflection principle to create a lattice which corresponds to three periods?     Which step fails to hold when we mimic the construction of an elliptic function to create a triply period meromorphic univariate function?   Sorry if the question is stupid. I do not have an access to the original proof that a triply periodic function cannot exist, either. So references are welcome! Combinef in R HTS package- constrain to keep forecasts positive? When using the combinef function from Rob Hyndman's very useful  for forecasting hierarchical and grouped time series, there does not seem to be a way to constrain the optimally combined forecasts to be positive- the starting forecasts can be positive, but can go negative through the reconciliation process.  The forecast.gts and forecast.hts functions have an argument to keep forecasts positive, but this does not seem to be an option when using combinef by itself with forecasts obtained by other methods.  Am I correct in this understanding, and if so is there a decent workaround? Can I start and stop a tile floor job? I am tiling my bathroom floor and don't soon have a full day to dedicate to the job. Is it ok to lay down a few tiles each day and come back to the job when I have time? I would only lay mortar for the tiles I have time to lay each day.    My concern is that the mortar wouldn't properly "join" to the previously laid sections of tile and cause an inferior result, but I'm not really basing this concern on any facts. That is what I'm hoping to learn with this question. Can I use a one time pad key twice with random plaintext? I know  that uses $x={\sqrt{2}}^{\sqrt{2}}$ to prove that there must exist an irrational to an irrational power that evaluates to a rational. But I don't know if $x$ itself is known to be irrational or rational.  Could someone enlighten me? Thanks! Reduce spacing between subequations Time travel short story where dinosaur doesn't taste like chicken I ran across this  and it reminded me of an old short story I read a long time ago.  I read it in a collection of short stories.  It would have been a book because I borrowed it from a school library.   Probably in the 1970s or 1980s.  The book and the story would have been older, though.  Probably from the 1960s or earlier.  In the story, a scientist has a machine that he can use to view the past.  It isn't like a TV or something, though.  It opens a portal into the past that he can look through.  It is very difficult to control, though.  Pointing it at a place and time is likened to working in a hurricane.  The portal jumps and moves about randomly.  The steadier he can hold it, the clearer the past appears.  When it is really steady, he can hear sounds from the past.  It never gets really steady enough to reach through.  They try pushing tools through the portal to pick up things in the past.  The steadier the portal, the easier it is to push tools through.  It never gets steady enough for them to push a tool all the way through, though.  It just gets easier to make progress.  One day, they have the portal open and it is acting really wild.  At some point the workers take a break.  The portal is still open, and while they are loafing the portal settles down by itself and becomes steadier than it has ever been.  So steady that a piece of the past falls through.  The portal scooped a chunk of the ground out of the past.  The chunk of ground contains a nest with dinosaur eggs.  The scientist  rescues the eggs, and they manage to keep them warm enough until they hatch.  The dinosaurs are some kind of harmless things, and become the lab mascots.  Always wandering the grounds, and in and out of the lab.  One day, the have the portal open again and one of the dinosaurs wanders into the lab and walks into some high voltage terminal.  Crash, bang.  Short circuit.  All the equipment to open the portal is destroyed, and the dinosaur is roasted from the flash.  The roasted dinosaur smells good, like chicken, and the scientist's son (who has been telling the story) takes a bite to see what it tastes like.  He says "It resembled chicken the way an asteroid resembles Jupiter."   It tastes fantastic. With all of their work ruined, and the ruins of a fortune in expensive equipment scattered around them, the scientists and the labworkers all chow down on dinosaur.  Half raw, half burned to a crisp from the explosion.  They eat the dinosaur down to the bones.  They start breeding the dinosaurs, and sell them as food.  The guy's father makes a fortune selling dinosaur meat, but remains unhappy.  With money from selling dinosaur meat, he rebuilt his lab but never ever got the portal steady enough to actually visit the past or take samples.  Does anyone know the name of the story and the author, and maybe what collection it might have been in? Visually stunning math concepts which are easy to explain Since I'm not that good at (as I like to call it) 'die-hard-mathematics', I've always liked concepts like the  or the , which are easy to understand and explain but are mathematically beautiful at the same time.  Do you know of any other concepts like these? Why aren't bounties refunded if they are not awarded? I have  with a bounty that will expire in a few days. It looks like nobody will get the bounty; only one answer was posted during the bounty period, and it has no upvotes.  In cases like this, the bounty is thrown away.  Why isn't it refunded instead, if no answerer has earned it? How do people come up with difficult math Olympiad questions? Newbie Question: in Blender 2.8 Adding Armature options missing? I did try searching for this but didn't find anything.   I've been following some tutorials for Rigging and have seen a lot of videos showing  Armature Templates available from the Armature sub option see attached.  On the version of blender I'm using 2.8 Beta Win 10 64 bit (23 April 19) I have no options to select anything.  Only the Armature menu heading is from the ADD option  which when selected provides a single bone.  Have these other options gone now or do I need to configure something within blender?  Thanks What's the difference between a microcontroller and a microprocessor? There are several Q&amp;A threads that explain how to download youtube videos using the terminal.  However, I would also like to learn how to extract the video's soundtracks as MP3 files--also using only the terminal.  Answers briefly explaining how to use youtube-dl or other similar utilities before explaining how to extract the MP3 would be ideal for the sake of having all the information in one place--even though this aspect has been covered in other posts.