Extension of Schengen visa, or apply for a new visa?
Is it possible to extend a tourist Schengen visa (12 more days)?
Securely erasing all data from a hard drive I am about to sell my old desktop PC and I am cautious about some of my sensitive information being available to the purchaser, even after reformatting the hard-drive, using data recovery software.  How can I securely wipe the hard drive so that the data on it cannot be recovered?  Although I specifically want help with my Windows PC, it wouldn't hurt if there were suggestions for Macs as well. Transpose of inverse vs inverse of transpose Show that every uncountable set of real numbers has a point of accumulation. How do I download a YouTube video? When typing &lt; or &gt; in LaTeX and compiling with pdflatex, the less than and greater than symbols appear at upside down exclamation points. I'm not in math mode. $\max(\{n: n+5 | n^5 + 5\})$ What is the maximum value of $n$ if $n + 5$ divides $n^5 + 5$, $n$ being a natural number? I tried to solve by binomial theorem but it failed. Will Google punish me if I import a story from my own blog to content sharing sites such as Medium.com? I've heard that Google punishes sites with duplicate content.   If I write an article on my blog then import it on Medium (basically a copy/paste) will Google regard it as a duplicate?   Medium.com is a blog platform (sort of). what is the difference between "yet" and "still"?   When we can use "still"? and when we can use "yet"?   Are they synonyms or not?  "The plan could yet succeed." Can I use "still" in that sentence instead of "yet"?  "I still don't understand." Can I use "yet" in that sentence too? How to fully backup non-rooted devices? Proving by induction that $ \sum_{k=0}^n{n \choose k} = 2^n$ This is a variation of the  questioned some time ago.  For a complex Hilbert space $H$ let $T: H \rightarrow H$ be a bounded operator. We call that $T$ is a trace-class operator if the following sum  $$\sum_{i}{\langle |T|e_{i}, e_{i} \rangle} &lt; \infty$$  converges, where $|T| = (T T^{*})^{\frac{1}{2}}$ is the absolute value of the operator.  Assume that  $$\sum_{i}{\langle Te_{i}, e_{i} \rangle}$$  converges for any basis in the space $H$. How to prove that if the aformentioned property holds then the operator is a trace class operator?  The progress on the problem is the following: Given an arbitrary bounded operator $T: H \rightarrow H$, one can use the following decomposition $$T = \big( \frac{T + T^{*}}{2} \big) ^{*} + i \big( \frac{T^{*} - T}{2i} \big) ^{*}$$  The latter line gives the decomposition $$T = A + i B$$ where $A, B$ are normal operators.  For the normal operators we can apply the spectral theorem that proposes that $T$ is unitary equivalent to  $$(UT U^{-1})(f(x)) = g(x) f(x)$$  where  $$U: H \rightarrow L^{2}(X, \mu)$$ $$g \in L^{\infty}(X, \mu)$$  Though this decomposition classify the operator in a broad sence, i see no direct way to conclude the statement. Are the any hints that may extend the previous argument? If not, are there any ways to conclude the statement? Do the automatic success and failure rules apply to skill checks? We had a rule check tonight that we couldn't answer. On the Pathfinder wiki I could only find info on natural 20s and 1s in regards to attack rolls and saves in combat.  Do they also apply to skill checks? So I noticed that many cards with tap-effects ship with a clause specifying that they can only be used on untapped permanents, such as  and .  So here's my question:   Doesn't that imply that, given the right situation, one can legally tap an already tapped permanent?   I'll give an example of the kinda scenarios this is relevant for: Can  activate her first ability when no untapped cards are around? Or, thinking untap-effects, could I bounce a forest with  even when there isn't a tapped creature available?  Notice that, unlike the previous batch of examples, the wording on these lacks the clause restricting their use to un/tapped permanents - does that mean that they aren't?  Any kind of clarification would be greatly appreciated here. Objects, shadows and reflections not rendering in EEVEE I started to work with EEVEE short time ago and I was amazed by the capabilities of this engine. However, I noticed something strange when I was rendering some tests. Some objects/reflections/shadows dissapear when they're off canvas. I imagine that maybe this is for save memory data, but it can be not suitable to some projects. To make my point graphical, I made a simple scene with simple objects. The main object is the sphere with a mirror-like shader. Out of focus there are different objects with different shaders. A yellow cone, a blue cylinder and a white cube light. But surprisingly, those objects dissapear when the composition is rendered. See the rendered animation below:  Notice that the blue cylinder is not even showing at all in the final render. And the blooming effect from the light cube also dies. I would like to improve this bahaviour and render the objects that are still out of canvas using EEVEE. Do I missing something like memory configuration or reflection/shadow tweaks? Is this caused by the EEVEE engine or by my GPU config (GTX1060)? Thank you in advance! Do I end up richer paying down a mortgage or contributing to an IRA? I have $10,000 extra cash that I can either use to pay down my 5% mortgage, or contribute to my IRA.  I'm 30 years old.  I hope to pay off the mortgage in about 5 years.  I'm stymied, because:   Paying $10,000 into my mortgage earns me $500 a year (in interest savings) for the life of the mortgage -- hopefully 5 years. Paying $10,000 into my IRA earns me roughly a $3000 lowering of my tax bill now (plus CD ROI of about 1% at retirement time.)   So I can get $2500 ($500 a year over 5 years), after which I will have paid my mortgage off with other money; or I could get $3000 in cash right now plus a bit of extra money when I retire.  Even ignoring the future benefits of the IRA contribution, it feels like I should put the money into my IRA: it's an immediate 30% return on investment, as opposed to a 5% return for 5 years.  But if I always make that decision, I won't be paying off my mortgage early, and that $500 will stretch out over 30 years, costing me $15,000!  Which actually leaves me with more money in the end?  What basic principle of math am I missing?  Update:  The principle of math I was missing is that, assuming I'm taxed at the same rate when I retire as I am taxed now, I end up with exactly as much money as if I had invested the $10k and not received a $3k tax reduction.  (Of course, my income level and tax laws will have changed by then, but let's ignore that.)  So the question simplifies to, "Should I put $10k toward eliminating a 5% debt or toward a 1% investment?" in which case I should clearly put it toward the mortgage.  I was confused by the government incentive into thinking that retirement investment was a sweeter deal than it actually is.  This is probably their goal, and probably a noble one :) Use XeLaTeX in Texmaker instead of pdfLaTeX iPhone screen randomly turns on I have always believed that it was ok to replace a capacitor with a slightly higher voltage rated one. eg 16v with 25v.Going higher than this would risk the capacitance value being out at the working voltage. However I just read the following quote from this       Electrolytic capacitors are non-ferroelectric with a very low dielectric constant. Their capacitance is derived from a very high surface area and nanometer thick dielectric layers. Their capacitance is not a function of applied voltage.‐Design Solutions For DC Bias In Multilayer Ceramic Capacitors (August 2010 Electronic Engineering Times)   So does this rule not apply to aluminum electrolytics? Eg will I have no issues replacing an electrolytic 25v 100uf with a 50v 100uf assuming both are low esr, similar footprint and good quailty? The topic which haunted me for two years until I gave up on it. But now I am doing engineering and this topic suddenly popped out of my textbook from nowhere. I seriously need to understand this topic because I wasn't able to do so in the past. I have read many book on 'energy' and it came to nothing. Maybe just because the many books I have read all said 'energy' is something which doesn't 'exist'! It is 'abstract'! It is just a number which represents the state or orientation of a system. But then I see so many examples that 'uses' energy to do 'work'. But the question here is that if anything doesn't exist in this universe, then how can the same thing be used to do something that exist?  My problem is that I didn't understood the topic 'energy' and all the other topics related to it (work, power etc.) "Being" or "to be"? Which is better structured?     "She loves to be herself instead of showing off"    or     "She loves being herself instead of showing off"   or     "She loves being and not appearing"