I shall travel to Mexico and then to the USA with a Lesotho passport. I have a 6 hour layover in London at Heathrow airport out of South Africa. I have a US visa in an old passport which is still valid until 2019.    DO I need a transit airside visa for London - I will not require to pass through customs/passport control while waiting at Heathrow.  DO I need to have my US visa transferred into my new passport before I leave home?  - Nothing has changed, such as my names in the new passport.
I have a valid B1/B2 US visa expiring about a year from now. The passport it's in expired a few years ago, and I recently got a new one.   The passport number does not match, but the national ID number, mentioned in both, does (it used to be the same as your national ID, but not anymore)  Can I travel to the US carrying both passports? Or is it asking for trouble? (I read a few years ago that it was possible, but that might have changed)  Should I just get a new visa to avoid potential complications?
I have two rasters: a digital elevation model (DEM) and a Landsat band. The grid resolution of both is 30 m, but the grids are not coincident (see image: the dark raster on top is the DEM; the light raster underneath is the Landsat band).  I want to perform some transformation of the Landsat band so that its grid aligns perfectly with the DEM grid. I've tried resampling the Landsat band to 30 m in ArcGIS using the DEM as a Snap Raster in the Environment settings, but this does not have any effect. I've also tried clipping the Landsat band to the extent of a vector polygon (that the DEM is also clipped to), while setting the DEM as the Snap Raster, but to no avail.  I suspect this is happening because both rasters are already at the same resolution (just on different grids), but I really need their grids to be aligned to be able to do any further analysis.  Can I do this in ArcGIS Desktop? D'Alemberts Principle to solve a Classical Mechanics problem I found this question on this very site and was curious on how to solve it using D'Alembert's Principle  .I already know how to do it by balancing the torque about toppling point so please don't post the latter as an answer . My attempt was to displace the upper sphere by $d\theta$ which gives its virtual displacement as  $rd{\theta}cos(\theta)$j(notice we are only interested in the y component becuz the only component of the applied force which is gravity in this case is the y component in the dot product the other components vanish) similarly the cylinder is also displaced $r'd{\phi}cos(\phi)$ where r' is the distance from the point of toppling of the center of mass. $r'cos(\phi)=H/2=r(1+sin(\theta))$ ,$r'sin(\phi)=R=r(1+cos(\theta))$ and $tan(\phi)=H/2R$ the equation coming from D'Alemberts principle is $mgrcos(\theta)d\theta=Mgr'cos(\phi)\phi$ I tried solving this but couldn't arrive at the right answer. Any help would be appreciated! I am using BusyBox on a small embedded ARM system.  I'm trying to read the "top" output, in particular for the Python process listed.  How much real memory is this process using?  Also what does VSZ stand for?  The system only has 64MB of RAM.   Mem: 41444K used, 20572K free, 0K shrd, 0K buff, 18728K cached CPU:   3% usr   3% sys   0% nic  92% idle   0% io   0% irq   0% sirq Load average: 0.00 0.04 0.05 1/112 31667   PID  PPID USER     STAT   VSZ %VSZ %CPU COMMAND   777   775 python   S     146m 241%   3% /usr/bin/python -u -- dpdsrv.py Polynomial $P(a)=b,P(b)=c,P(c)=a$ Let $a,b,c$ be $3$ distinct integers, and let $P$ be a polynomial with integer coefficients.Show that in this case the conditions $$P(a)=b,P(b)=c,P(c)=a$$ cannot be satisfied simultaneously.  Any hint would be appreciated. Functional equation: $f: \mathbb{R} \rightarrow \mathbb{R}$, $f((x + 1) f(y)) = y (f(x) + 1)$ I'm wondering something. Whenever i right click on minecraft and click open with another application, i try to find Java JDK. I have installed it for minecraft itself, but i just cant find where java is on the list of other applications. Any help? Why is compactness in logic called compactness? In logic, a semantics is said to be compact iff if every finite subset of a set of sentences has a model, then so to does the entire set.   Most logic texts either don't explain the terminology, or allude to the topological property of compactness. I see an analogy as, given a topological space X and a subset of it S, S is compact iff for every open cover of S, there is a finite subcover of S. But, it doesn't seem strong enough to justify the terminology.   Is there more to the choice of the terminology in logic than this analogy? How does a Support Vector Machine (SVM) work? When to use an interface instead of an abstract class and vice versa? Atomic Physics: stimulated emission I'm studying a chapter about atomic physics right now but there's thing I just don't seem to understand. When stimulated emission occurs, there's an incoming photon which stimulates the atom to go an energy level lower with the result that a new photon gets emitted.  Can someone explain the reason why the incoming photon stimulates the atom to emit a second one? To me it seemed more logic for the atom to absorb the photon and go an energy level up. There seems to be a phenomenon which I don't know about. Integrate $\int_0^{\pi/2} \frac{1}{1+\tan^\alpha{x}}\,\mathrm{d}x$ Evaluate the integral $$\int_0^{\pi/2} \frac{1}{1+\tan^\alpha{x}}\,\mathrm{d}x$$ What are all the member-functions created by compiler for a class? Does that happen all the time? Can the union axiom be weakened? We have a fairly big MS SQL 2008R2 database that resides on a SSD drive. The drive itself only has ~110Gb of space, and the database files are the only files on the drive.  The database is in "Simple" recovery mode, and only has two files, .MDF and .LDF.   The disk is now nearly full: the MDF is currently 109Gb in size. However, SSMS tells me there's nearly 18Gb of "Space Available" (in the 'General' properties page), and if I go through the motions of Shrinking the file it also tells me there's 18Gb of space free. SSMS also tells me the database size is around 132Gb, which surprises me - that wouldn't fit on the drive!  From what I've read, shrink is a really bad idea. However, I'm starting to see replication errors (could not allocate space for object). We've previously tried shrinking the database, but within a few hours the file was back to it's original size.  How should we proceed - given there's apparently 18Gb of free space, should SQL automatically use that free space? Or is it as simple as: we really need more disk space? Can a 20V 4.51A power supply be used with a computer that requires a 19V 3.42A power supply? In a Discord call on the desktop app and my voice cannot be heard by others. When I use Discord  through browser I can be heard. Any help appreciated. mysqli_fetch_assoc() expects parameter / Call to a member function bind_param() errors. How to get the actual mysql error and fix it? Select from list of reasons when performing downvotes C++ equivalent of java's instanceof What is the preferred method to achieve the C++ equivalent of java's instanceof? I accidentally discovered () that a closing square bracket within an optional argument delimited by [ ] can cause problems.  Here is example code illustrating the issue:  \documentclass{article}   \begin{document}  \tableofcontents  \section[Square brackets ([ and ])]{Square brackets: [ and ]} % bad: the TOC now has "Square brackets ([ and", and the actual title is a mere ")".  Some text.  \section[{Square brackets ([ and ])}]{Square brackets: [ and ]} % good (works as originally intended)  Some text.  \end{document}   The text to be used as the optional (as well as the non-optional) argument contains a ], and this character is not supposed to function as the optional argument terminator but as a matching square bracket/parenthesis. Perhaps this is as it should be, but the question is how to best circumvent any potential problems. Enclosing this in a group works, but I don't know whether doing this has other side effects (perhaps not here in the case of \section but hopefully someone else has a better example of where grouping could lead to a problem). There is no (obvious) way other than writing [{ }] because [ and ] are not normally escaped. That [ and ] are normal characters and bear syntactic function (as optional argument delimiters) creates this potentially problematic situation.  Is simply enclosing the entire optional argument in a group ({ }) a good solution? Are there other/better ways?