Dublin airport: am I going through passport control?
Do I need an airport transit visa for Dublin, Ireland en route to the UK?
Isomorphism between $\mathbb{C}^* $ under multiplication with $\mathbb{C}$ under addition. Does there exists an Isomorphism between $\mathbb{C}^* $ under multiplication with $\mathbb{C}$ under addition.  Attempt In my opinion It does not exists.  If there exists such an isomorphism say $\phi :\mathbb{C}^* \to \mathbb{C}$ then, from the fact that Isomorphism takes identity to identity we have $$\phi \left( 1 \right)=0$$  From the fact      Given $\phi:G \to H$ be an isomorphism, then For a fixed integer $k$ and a fixed group element $b$ in $G$, the   equation $x^k=b$ has the same number of solutions in $G$ as does   the equation $x^k=\phi\left(b\right)$ in $H$.   We have $x^4=1$ and $x^4=0$ must have same number of solutions, but the solutions to these equations are 4 and 1 only. How to change Gnome-Terminal title? I have several instances of terminals running in my working environment, what I would like is to set a specific title for each one, in order to have a clear idea what purpose the specific terminal serves i.e. Apache, editing_ini, postgres etc...  Of course from the command line. How would one write object-oriented code in C? What are some ways to write object-oriented code in C? Especially with regard to polymorphism.    See also this Stack Overflow question . Baking lots of bread - keeping a yeast starter Like many people sheltering-at-home, I'm baking . My yeast supply is running low, and I'm not sure I'll be able to get more on demand. I'd like a simple way to make sure I have yeast on hand for my next batch. Could you all recommend a method for storing a starter culture?  Specifically:   How should I store it (how much? where? I have a fridge ~4C and a wine cooler ~13C)  How often should I feed it? With what? Should I divide the culture when feeding?  How much should I use when baking? Can I treat it like dry active yeast, or does it need more/less time?   For some other context, I'm a novice at making bread (I've made it a few times, and others in my family make it more often). I see lots of advice on sourdough starters, but am interested in something that's a replacement for dry active yeast (unless sourdough starters are actually easier to maintain). I found a  that was similar, but it focused on long-term storage of yeast and the answers did not describe how to use the starter.  Your advice is appreciated. new array.sty and colortbl.sty incompatibility? What is the importance of the Diophantine inequality $\frac{1}{p} + \frac{1}{q} + \frac{1}{r} > 1$? In Humphreys' book  Introduction to Lie algebras and Representation Theory(3rd printing, p.62), the Diophantine inequality $$\frac{1}{p} + \frac{1}{q} + \frac{1}{r} &gt; 1$$ appeared while classifying all Coxeter graphs of irreducible root systems. Under the assumption $p \geq q \geq r \geq 2 $, the possible triples turn out to be $(p,2,2), (3,3,2),(4,3,2),(5,3,2)$, which correspond to the Coxeter graph $\text{D}_{p+2}, \text{E}_6, \text{E}_7, \text{E}_8$, respectively.  It seems quite straightforward to solve the inequality in positive integers, but Humphreys said that      This inequality, by the way, has a long mathematical history.   without further comment. So I want to know if this Diophantine inequality has any important significance, or if it has appeared in other context (maybe relevant history) before. Getting secondary citations right I have some questions regarding secondary citations (in an computer-science research paper that should be published in a journal). I know that they should be avoided when possible, but it is not always that easy. More specifically, my situation is this:  Article A says:     The average value of ... in ... is ... [B]. [C]’s study says that in ... the value is ...   This statement is exactly what i need for my paper. If I read [B] and [C], I see that [A] cited them correctly and if I would have found these two other articles myself, I would have written the same.  Now how to cite this in a correct way?      [B] and [C] say (cited in [A]) ...   and do a “bad” secondary quote;    [B] and [C] say ...   and neglect the investigation done by [A] and peform citation plagiarism;    [A] says ...   and neglect that the data was the achievement of [B] and [C].    [A] says based on the findings of [B] and [C] ...   and do a secondary quote again. PrintWriter and PrintStream never throw IOExceptions Some days ago I realized that  (as well as ) never throw an IOException when writing, flushing or closing.  Instead it sets an internal flag (trouble=true) when an error occurs. It's not possible to get the exact exception, but only if there was some exception ().  My question is: why would one want to have such behavior? Isn't that bad API design? How can I transfer large files from Linux to iPad over a cable or wifi? I am looking for a way to transfer large files to the iPad without using iTunes or pushing to and pulling from a remote server.  I run an Ubuntu laptop as my only OS at the moment and want to be able to transfer movies to my iPad.  I currently transfer most of my files by way of the dropbox app which works well for small files but is quite slow for larger files and eats up my bandwidth.  Ideally I'd like to be able to transfer over a cable or through WiFi.  Thanks for any tips. Limited options in a certain area? Ok so i am a bit of a noob in blender, so I need help with this.  I am trying to texture something, but there is no texture button where there should be, because the blender edge window cuts it off here's a picture When would I need a SecureString in .NET? Ohm's law states that  electric current is directly proportional to voltage provided that physical conditions like temperature remain constant i.e. $$V = IR$$  On the other hand,  $$\text{Power = Voltage} \times \text{Current}$$  So here it seems that the higher the voltage, the lower the current, provided that the power remains constant (i.e. current is inversely proportional to the voltage here which is against Ohm's Law.).   Now my question is how do physicists explain this apparent contradiction? Or maybe this not a contradiction because I am analysing things incorrectly?   P.S.: I am a tenth grade student so please refrain from the usage of highly complicated terminologies in your answers. How to evaluate a math expression given in string form? Duty Free in the USA. Why do I have to be given my purchase as I board the plane? I am not one for buying things in airports but recently my wife asked me to get her an alcoholic beverage while flying from the USA to Ireland (JFK-DUB). I made the purchase in JFK and was surprised to be told I had to collect it when departing for my flight as I board the plane. The sales assistant's English wasn't their best so I may have misheard and my Yorkshire twang may have thrown her, but I was somewhat surprised as to why I couldn't carry the bag myself to the plane.  Is there a law that prevents me from carrying my purchase to the plane or is this an added service I was charged, which I was duped into paying?  When boarding the plane there were several others who had to pick up their sealed duty free bags (why sealed?) so it wasn't just me. No explanation was given. Fundamental question about dimensional analysis How do I know I have the correct exposure when shooting in manual mode? I have a Canon XTI which I've been using for a few years now. Most of the time I'm been shooting in one of the "semi-manual" modes like aperture priority or shutter priority, but now I'd like to try using full manual mode. I should have a new EF-S 17-55 f/2.8 delivered when I get home today. Before I was using a variable aperture Sigma 17-70 which made manual mode more difficult with the aperture changing arbitrarily.  I understand the effect of changing aperture and shutter speed, but right now I'm accustomed  to only controlling one at a time. The camera is usually setting the other to get the right exposure automatically for me. So if I'm controlling both how do I know I have the correct exposure? I understand I need to use the metering in my camera but I'm not sure exactly how do do that.   First when should I be using each of the metering modes (Evaluative, Partial, Center weighted, or Spot)? These just change the area of the scene which is metered correct?  How do I know what the meter should read off a specific object? Obviously if I just happen to be shooting a 18% gray wall then it should be at zero, but that can't apply to everything? If I'm shooting a black cat and take a spot meter reading off of the cat then the meter should read less then zero right? But how do I know how much less then zero? Are there rules of thumb I can follow? I've ordered a couple gray cards with my new lens. So experimenting with those should help.  How often should I be changing these settings? Say I'm at a party indoors which is consistently lit. I should be able to set the aperture, shutter speed, and ISO and just forget about it unless the lighting changes correct? Does the same apply to outdoor scenes? I've been hesitant to use manual mode in the past because I felt like I was spending a lot of times messing with settings before each shot. But not I'm realizing that this is really only the case when the lighting changes, or I want a different style of photo such as a different depth of field.  Finally, does exposure change with distance to the subject? For example say I want to take a picture of a statue with correct exposure using a gray card. I'd place the card on the statue, and while being careful not the block the light on the card find the correct exposure by spot metering the card. If I were then to step back 20' to get the whole statue in frame would I still have the correct exposure? A proof that $1=2$. May I know why it’s false? Fold a plane. then fold again Imagine a piece of paper and you fold it in half and then fold it again. that's what I am trying to do and cant. If I use bones the influence of the bones won't allow me to because I need 2 bones to control the same area. If I try shape keys it just deforms the mesh if I try to make it in multiple steps or does the wrong animation because it draws the shortest path instead of rotating from a point like a piece of paper would. Best Place to put Feature Requests? The only place I am aware of is the . The question is as below:      Show that each vertex $v$ of a tree $T$ appears $deg(v)-1$ times in the Prüfer encoding of $T$, where $deg(v)$ is the degree of $v$ in $T$.   For this, I think there are 3 scenarios a leaf should be considered for: (1) when it is a leaf as part of a tree; (2) a leaf that has been discarded; (3) the remaining edge. I feel like this will result in a short proof which is only two (or so) statements long, but at the same time, feel it is too simple.   EDIT: I've had a look at this again and narrowed it down to 2 cases:   Case 1: The vertex $v$ in question has $deg(v)\ge2$. $v$ then loses its neighbours as the algorithm is applied repeatedly until $v$ becomes a leaf itseelf. At this point, $v$ is attached to another neighbour, leaving an edge. This means the algorithm can no longer be applied and we have obtained the final Prüfer Encoding for the tree $T$.  Case 2: The vertex $v$ has $deg(v)\ge 2$. It loses its neighbours as the algorithm is applied repeatedly but is deleted itself at some point in the process.   Have I gone about this wrong?  Thank you.