Are there any large maritime data sets?
What are the existing datasets of world maritime routes?
Spin or rotate an image on hover Detecting constexpr with SFINAE Ways to go from A to B(proof) How can you find and replace text in a file using the Windows command-line environment? Neutrino Oscillations and Conservation of Momentum I would like to better understand how neutrino oscillations are consistent with conservation of momentum because I'm encountering some conceptual difficulties when thinking about it. I do have a background in standard QM but only rudimentary knowledge of particle physics.   If the velocity expectation value of a neutrino in transit is constant, then it would appear to me that conservation of momentum could be violated when the flavor eigenstate at the location of the neutrino source is different from that at the location of the interaction, since they are associated with different masses.  For this reason I would think that the velocity expectation value changes in transit (for instance, in such a way to keep the momentum expectation value constant as the neutrino oscillates), but then it seems to me that the neutrino is in effect "accelerating" without a "force" acting on it (of course, since the momentum expectation value is presumed constant, there may not be a real problem here, but it still seems strange).   Any comments? Are there functions or packages in Mathematica to sort subsets in lex order, colex, revlex, etc.? Nick Fury told Captain America that he has been "asleep" for nearly 70 years. If Dominic Cooper was playing Howard Stark Senior (grandfather of Tony Stark) then it is fine, but if he was playing Howard Stark (father of Tony Stark) then after 70 years he should be around 90 or above.  Tony Stark, his son, should be 60 to 70 years.  Is that possible?  Tony doesn't look 70 years in The Avengers. I'd like to create a PDF report with knitr with LaTeX-code in RStudio with biblatex for citations. However, the in-text-citations are always undefined and no bibliography is printed. The same bibliography works perfectly with a pure .tex-document stored in the same folder and containing the same citations, same path to the .bib-file etc. However, as for all references (also with hyperref) I have to compile twice. I thought this might be the problem with knitr (that the compilation is run only once), but the hyperref-references to figures work well. Any idea what might go wrong with the bibliography when using knitr and how I can solve the problem?  MWE:  \documentclass{article}  \usepackage[style=authoryear-comp, maxnames=1, bibencoding=utf8, backend=biber]{biblatex} \bibliography{ZoteroOutput.bib}  \begin{document}  According to the literature \parencite{gonzalez2003} we can assume...  \printbibliography  \end{document}   From the log-file:  Package biblatex Warning: Please (re)run Biber on the file: (biblatex)                mwe (biblatex)                and rerun LaTeX afterwards. How do I make Firefox start always maximized? I am setting up Ubuntu with gnome for my grandma. How can I make firefox start ALWAYS maximized. Compactness of $A:=${$f \in C[0,1], |f|_\infty \le K, |f'|_\infty \le M$} Here we use infinity norm as metrics for $C[0,1]$. The professor claims that this set is compact. I can show this set is relative compact by Arzela Ascoli, i.e., for each subsequence there is a further sub-subsequence that uniformly converges to a continuous function on $[0,1]$. But it is not intuitive to me why this set is compact, i.e. the limiting function also satisfies $|f'|_\infty \le M$. Is it true that $A$ is close and therefore compact? passive Vs active or omission of 'which is' What is the part of speech of 'regarded' in the following?     "a quality of beauty and intensity of emotion regarded as characteristic of poems"    Why isn't it "... [which is] regarded ..."?  And in another case:      "a small lizard with wide feet, found especially in warm countries"     And also:      "Words used to describe writing or speech style"    In all these examples, why shouldn't the verbs be in their passive form (e.g. which is found, words that are used)?   I am a ESL learner and I am very confused by these usages! Ubuntu 18.04: switch back to /etc/network/interfaces Starting sometime around Ubuntu 18.04, the Ubuntu devs stopped using the classic /etc/init.d/networking and /etc/network/interfaces method of configuring the network and switched to some thing called . This has made a lot of people very angry and been widely regarded as a bad move. Is it possible to remove netplan and use the correct /etc/network/interfaces method for configuring the network? Ever since mods gained the ability to undelete comments, deleting them has become easier as the confirmation dialog was removed.  However, this is not the case in the mod queue &mdash; I still get a confirmation dialog for each comment I want to delete in the queue under a custom-flagged post (single-comment flags can be deleted just fine). And since this is the place from where I delete comments the most, it can be annoying.  In addition, the "purge comments" button, when invoked from the queue, refreshes it, so I have to scroll back down, remember which post I just purged, and mark the flag as helpful. Usually not a big issue but if there are multiple "obsolete comments" flags, then it can get confusing.  Could the workflow for comment thread moderation from within the queue be improved? Ideally, make comment deletion work like everywhere else on the site, and make the purge button AJAX-based like the comment deletes. Reading data from a relational database into a LaTeX table I'm using Tex Live 2009 on Debian squeeze. I can upgrade if I really, really  have to, but I'd rather not. I was wondering if it would be possible to do the following.  Given some data in a (relational) database, can I extract it and automatically format it in a LaTeX table, so one would not need to manually recreate the LaTeX table if the data changes? Could one do such a thing with Lua? One would normally use a suitable language database adaptor for this, and I see Lua has . I'd like to use PostgreSQL. I'm currently using version 8.4.  Solutions not involving Lua are also fine. Just to be clear, I don't know anything about Lua and my knowledge of LaTeX programming is also extremely skimpy. I'm looking for a recipe which I can adapt if necessary. While this is not really important for my current use case, it seems like a useful general technique if possible. My final goal is to generate Impulse Response Functions in R.  I have variables that are non stationary when I set k = 5 in a Unit Root test, and they are cointegrated which to my understanding prompts the use of the VECM, from which the Vec2Var argument is used to then generate IRFs. However, my response functions from this methodology do not decay over time and mostly do not revert to the zero line.  Furthermore, I noticed that when I input first differenced variables into the VECM as opposed to level data above, response function do revert to the zero line. Therefore my first question is: 1) is it appropriate to use differenced variables in a VECM model?  Secondly, as an alternative I am considering restricting the number of lags used in the Unit Root tests so that the variables are not all non-stationary; in this case 2) would the use of VECM be void and the VAR with first differences be a more appropriate model? Again, using differenced data is giving me better response functions that revert to zero in the long run. However, 3) is it ok to use the VAR for stationary/non-stationary data in levels where these variables are still cointegrated?  Also, I am using growth rate variables, 4) should I still long transform all variables and use logs in all tests?  Thank you for the help! Do greenhouse gasses make the world habitable? An ageing gent says he does not accept this statement:  It's a fact that greenhouse gases, predominantly water vapour, keep the Earth  from being hostile and cold; that CO2 albeit in trace quantities is also a  greenhouse gas and therefore helps keep the planet warm...   I know no more about why he rejects this statement - maybe it is that water vapour alone would do the job. The gent in question has a first class degree and a doctorate in physics.    Is there a debate within the physics community over this or am I misunderstanding? Finding minimum bounding extent of given pixel value within raster? Short story: rocket fuel which oxidizes iron destroys life on earth I'm looking for the title of a short science fiction story, probably published in a Hugo winner collection 30 years ago. In the story, scientists have developed an extremely efficient rocket fuel that has one dangerous side-effect: it oxidizes iron. A man takes off in a rocket powered by this fuel but returns to find the earth completely devoid of life. His subsequent investigation reveals that a single drop of the fuel began a domino effect, as the substance oxidized all iron it came into contact with. In the end, the man is dying.  He drags himself to the ocean, believing that if he can get his living cells into the water they will restart the primordial soup. It is commonly stated that there are four fundamental forces, or interactions, in nature. It is natural to consider which of those is responsible for the normal force we meet in elementary physics. What is the nature of the force exerted on a body by the floor on which it rests?  Of the four forces, the only one that seems relevant is the electromagnetic force, and I always assumed the repelling force in question is ultimately the EM one. The Wikipedia article on  seems to agree:     Molecular and quantum physics show that the electromagnetic force is the fundamental interaction responsible for contact forces.    An alternative explanation is that the force results from Pauli's Exclusion Principle; however, reasonable as it may seem, it doesn't seem to answer the question of what force is actually at play here. The exclusion principle isn't a force, or at least it's not normally described as such.  I've recently come across a rather forcefully presented argument that states that the normal force is a macroscopic force that is not directly reducible to the EM force, or to any of the other forces; rather, it does indeed result from Pauli's Exclusion Principle by way of interaction of electron wave functions. The argument further claims that attempts to correct the Wikipedia article have met with the usual "source needed" objections, and that this topic is either misunderstood by or poorly covered in the standard texts.  (The argument can be found ).   Which way is it? How can I create a select menu in a shell script? I'm creating a simple bash script and I want to create a select menu in it, like this:  $./script  echo "Choose your option:"  1) Option 1   2) Option 2   3) Option 3   4) Quit     And according to user's choice, I want different actions to be executed. I'm a bash shell scripting noob, I've searched the web for some answers, but got nothing really concrete.