How do I install Ubuntu on a USB?
How do I install Ubuntu to a USB key? (without using Startup Disk Creator)
Is there a way to absolutely force a Log Out, Shut Down, or Restart with open tabs and unsaved documents? I could not find any relatively simple way to log out of a public use Mac quickly with many tabs open and unsaved document in the background without resorting to sudo shutdown -h now.  The reason I ask is that sometimes a user will have his/her account logged into the iMacs here at school and they would try to log off and then leave, thinking it has completed but the process is interrupted by Safari and Office apps, leaving their account, mounts, and websites still accessible to the next person who sits down.  Obviously a shortcut string would be nice instead of posting a note telling the person to type arcane things in a terminal. For example, just having them try to find Terminal.app is going to be a chore.  This doesn't seem to make sense because the user can just quit each app and click a few dialog boxes but unlike you and I to whom repeatedly pounding Command-Q while hitting the spacebar and D keys are probably second nature. Can I make a public directory under a private directory? I have a personal folder /a/b on the server with permission 700. I don't want others to list the contents in /a/b. The owner of /a is root.  Now I need to open the full authorities of directory /a/b/c to all users.  I changed the permission of /a/b/c to 777 but it is still inaccessible for others. May I get off in an intermediate city of my route during transfer? I want to go from Panamá to Turkey. There're direct flights of Turkish Airlines that are expensive. And there're flights Panamá -&gt; Istambul -&gt; Baku there're cheaper 2 times of the same airline. The transfer in Istambul takes 6 hours.    Will it be a violation if I buy a ticket Panamá -&gt; Istambul -&gt; Baku and leave in Istambul? Can I start and stop a tile floor job? I write financial applications where I constantly battle the decision to use a double vs using a decimal.  All of my math works on numbers with no more than 5 decimal places and are not larger than ~100,000. I have a feeling that all of these can be represented as doubles anyways without rounding error, but have never been sure.  I would go ahead and make the switch from decimals to doubles for the obvious speed advantage, except that at the end of the day, I still use the ToString method to transmit prices to exchanges, and need to make sure it always outputs the number I expect. (89.99 instead of 89.99000000001)  Questions:   Is the speed advantage really as large as naive tests suggest? (~100 times) Is there a way to guarantee the output from ToString to be what I want? Is this assured by the fact that my number is always representable?   UPDATE: I have to process ~ 10 billion price updates before my app can run, and I have implemented with decimal right now for the obvious protective reasons, but it takes ~3 hours just to turn on, doubles would dramatically reduce my turn on time. Is there a safe way to do it with doubles? What does it mean to accept an answer? How do I accept an answer, and what are the rules? Can I accept my own self-answer? What are the reputation benefits? Which answer should I accept? Should I upvote the accepted answer? What should I do if none of the answers are suitable?      For more information, see "" in the . Generating random numbers without repetitions Combining jquery functions - on() hover/mouseenter/mouseleave Is the solution to a question regarding four smaller masses on a rotating hollow sphere accurate? I was doing the question :     A uniform 8.40-kg spherical shell, 50.0 cm in diameter has four small   2.00-kg masses attached to its outer surface and equally spaced around it. This combination is spinning about an axis running through the   center of the sphere and two of the small masses (see ). What friction torque is needed to reduce its angular speed   from 75.0 rpm to 50.0 rpm in 30.0 s?   I understand how to get $\alpha$, and how to get $\tau$ from $I$ and $\alpha$. What I do not understand is their computation of the moment of inertia. The question did not provide any information regarding the shapes of the masses, but the solution (which writes $I=\frac{2}{3}MR^2+2mR^2$) seems to assume that the masses are point particles. Thus, the two masses along the rotational axis have a moment of inertia of 0 ($r=0$), and each of the other two masses has a moment of inertia of $I=mr^2 =mR^2$, where $R$ is the radius of the sphere and $r$ is the distance from the axis.  But why are the masses considered to be point particles? I wanted to use the parallel-axis theorem to determine the moment of inertia about the rotational axis; not knowing the shape of the masses made this impossible, since I couldn’t find the moment of inertia about the CM. If I knew $I_{CM}$, then couldn’t I use $I_{axis}=I_{CM}+mR^2$ for the two masses not on the rotational axis and $I_{CM}$ for the two that are? That would make $I_{total}=\frac{2}{3}MR^2+4I_{CM,\:mass}+2mR^2$ Would that not be a better way of solving this problem? How can I make sure texts from friends with iPhones don't go to iMessage instead of my Android phone? I have always used an Android phone, but text messages from certain friends get hijacked by iMessage. How do I prevent iPhones and MacOS Messages from sending me iMessages? I need all messages to be SMS or MMS. Some friends with iPhones will text me, but I don't receive the message. Today I noticed the Message app on my Mac had notifications. I never open this app since I don't use iMessage, but I looked today, and found multiple &quot;lost&quot; messages from several weeks ago. Please note that this is NOT the same question as . My Android phone is not, and has never been, registered with iMessage, and I have already followed those instructions. Another poster () had the same question as me----but it was closed, being deemed as the same as the Removing phone number question. It's actually fairly different. I have tried:  Leaving my Messages app closed on my Mac. But somehow messages from these people get hijacked. Deregistering my mobile number using Apple's online Deregister iMessage tool. When I attempted this, I got the message &quot;Your phone number is not registered with iMessage.&quot; Finding a setting on my Android phone that addresses this. The problem is apparently (and logically seems to be) on the Apple end.  Things  says he tried:   Closing Messages.app. I still get macOS notifications of messages. In Messages &gt; Preferences… &gt; Accounts &gt; [my email address], untick &quot;Enable this account&quot;. Then my friends messages disappear and I never see them at all, at least until I reenable in Messages.app. Looking in System Preferences and on icloud.com and appleid.apple.com    to see if there is some setting I can disable—but I've not found    anything relevant. Using Apple's Deregister iMessage tool to unregister my mobile    number. When I attempted this it gave me the message &quot;Your phone number is not registered with iMessage.&quot; How to use manual partitioning during installation? I'd like to see the full How-To on how to use manual partitioning during Ubuntu installation. The existing guides (at least those I found here) cover only automatic part and leave untouched the manual part (or extremely short and contain no pictures).  I'd like to cover such situations:     If your disk contains other systems: Can I leave the Schengen Area (and come back) while my non-eea spouse resident card application is being processed? My wife and I recently moved to Germany. She's a Swedish citizen, and I'm American. It'll be December before I can actually apply for my residence card, because my appointment to register our address is so far out - the local police station was all booked out and we didn't get an apartment right away.  I imagine that I won't be getting my residence card until well after Christmas, by which time my 90/180 days will be passed. What if I want to leave to, say, London for the holidays? Will I be allowed back in? I hit day 90 around the 21st of December. I could maybe leave on day 89 and come back on day 90 (with my wife and our marriage cert), or use this Polish solution: , since I can't be expelled from Germany for overstaying my visa while my application is processing.  Both of those seem a bit risky though. Am I reading too far into it, or is this a legitimate concern? Will I get some sort of documentation saying I have a residence card application processing? Compiling LaTeX document empties .bbl file I'm trying out biblatex for the document I'm compiling, using the biber backend on my miktex distribution. Everything, including biber, should be up to date, assuming the MiKTeX repository currently holds the latest versions of everything.  This is what the biblatex documentation (p. 101) says about how often I have to run biber to update my .bbl file:     Whenever a reference to a work which has not been cited before is   added, this procedure must be repeated. This is also the case if the   last reference to a work which has been cited before is removed   because some citation labels may change in this case.   So if I make changes to my document (which is a very common activity in the process of writing a document), but leave the citations unchanged, I should not have to re-run biber before compiling the changes. However, every time I compile my document, regardless of the compiler or documentclass, the .bbl file is emptied. Consequently, the next time I compile the document without running biber, the bibliography is removed (seeing as the .bbl file contains nothing), and all my citations are broken. For this reason, I have to run biber before every time I compile the document, which largely counters the benefit of externalizing the bibliography in the first place.  How can I make the compilers stop overwriting my .bbl file and make everything behave as described in the biblatex manual?  Upon investigating the contents of the auxiliary files, I found that the .bbl file (after running biber, before compiling) begins with the following lines:  % $ biblatex auxiliary file $ % $ biblatex bbl format version 2.3 $   Does the biblatex version 2.8 still mark the .bbl files as version 2.3? If not, could this be the problem? And if so, why does my 2.8 version of biblatex (partly) behave as version 2.3?  Any help solving this problem would be much appreciated. The general consensus is that the single best indicator of a fund's future performance is the its expense ratio . If you look for more than 5 minutes online you discover the  approach to investing; the , etc. It looks like the less you pay for a fund (and therefore the less it's managed), the better it does in the long run.  So why is it that in peoples' 401(k)s there are so many high-cost actively managed funds? Furthermore, why are there so many high-cost actively managed funds in the first place? Shouldn't the market reflect the fact that actively-managed funds typically don't beat the index they benchmark to and and react by purging itself of these crappy funds? How do I download a YouTube video? What are instructions on how to download videos from YouTube?    Notice: Terms of Service Violation  Please be aware that by following any of the answers below, you will be violating YouTube's . In particular, from Section 5.B.:     Content is provided to you AS IS. You may access Content for your information and personal use solely as intended through the provided functionality of the Service and as permitted under these Terms of Service. You shall not download any Content unless you see a “download” or similar link displayed by YouTube on the Service for that Content. You shall not copy, reproduce, distribute, transmit, broadcast, display, sell, license, or otherwise exploit any Content for any other purposes without the prior written consent of YouTube or the respective licensors of the Content. YouTube and its licensors reserve all rights not expressly granted in and to the Service and the Content. a year on: what does it mean? PLease, dear native English speakers, help me to understand the meaning of the expression "a year on" within the context "The reality is that, a year on, a true 4K standard is still very much a work in progress..." Thank you a lot! Derivatives: enter "evaluated at" vertical bar with multiple values as subscripts Sorry for the long title, but how do I enter evaluated at (for a derivative), with multiple valuation criteria at the bottom of the the big | line?  Thanks! How to show  tag literally in / tag? Can there be more than one power series expansion for a function. I guess the answer is NO, for polynomials.  I know that there are more than one series expansion for every function.  But I am talking about power series here.  All Ideas are appreciated Does WaitForMultipleObjects() reset all auto-reset events?