Lights entering the prism with different wavelengths at the same angle. why go to different directions? what happens step to step between the protons&amp;electrons in glass and the photons? what is the wavelength of interest in the direction the light goes? please don't tell they have different index of refraction.
It is well known that a  can "split light" by separating different frequencies of light:    Many sources state that the reason this happens is that the  is different for different frequencies.  This is known as .  My question is about why dispersion exists.  Is frequency dependence for refraction a property fundamental to all waves?  Is the effect the result of some sort of non-linearity in response by the refracting material to electromagnetic fields?  Are there (theoretically) any materials that have an essentially constant, non-unity index of refraction (at least for the visible spectrum)?
On iPhone it's very easy to clone an app (running multiple copies of the app on the same device); e.g.:    Is it possible to do this on Android? Probability that the bag contains all balls white given that two balls are white A bag contains $4$ balls .Two balls are drawn at random and are found to be white.  What is the probability that all the four balls in the bag are white?.  The options are $\large\frac{1}{5}\space ;\frac{2}{5} ;\frac{3}{5} ;\frac{4}{5}$  My work: It's given that two balls are white.So the rest of the balls could be    all white One of them white none of them white   So among the three above possibilities only one satisfies our conditions so the probability is $\frac{1}{3}$.But it not even the options given. What's wrong with my work? Incorrectly answered 'No' to "Any previous visa refusals..." on a UK Standard Visitor visa application. How can I fix my mistake? I'm from Lebanon and I've been working in Saudi Arabia for nine years. In 2012, I put the money that I collected from my job as a teacher in my father's Lebanese account since I didn't have one in Lebanon. During the interview, my interviewer told me that my application will be rejected because I don't have proof that this money is mine and clearance officer will think someone else gave me the money. I didn't know that I had to bring with me from Saudi Arabia an employment letter and bank statements to prove that this money is mine and I earned it by working in Saudi Arabia. Anyways, my visa did get refused as my interviewer had told me it would be.    Last May, I was granted a US visitor visa Multi Entry for 5 years. I wanted to visit the US in August for 10 days but my mom entered the hospital so I had to postpone it. Now I'm applying for a teacher training program in the UK. I received an invitation letter from Brighton University and so I applied for a UK Standard Visitor visa. After I paid and printed the application, I realized that I answered the question Any previous visa rejections ... with "NO" and I don't know how should I fix this.  Please note that I still didn't give my biometrics, I still didn't use my US visa which I received on May 2016, I paid for my application so I can't amend it online. I'm supposed to give my biometrics and submit my documents this Monday.  If I don't say anything will they check it and refuse me?    Will my US visa be an advantage and they will disregard the previous rejection or should I correct it when I submit my documents this Monday? Possessive of a word that is already possessive If the cricket ground Lord's is a possessive, what if you want to describe something belonging to Lord's? Would you say:     I was very impressed by Lord's's customer services.   It doesn't look right, so what is the correct way of writing it? Time limit on accepting an answer Why is there a 15 minute time limit on accepting an answer in StackOverflow? Scaling in object and edit mode My question is: why do Object mode scaling and Edit mode scaling seem to be incompatible? I'm quite new to blender, so I may not know sth important about these modes. The actual case is:  I create a cube, which is 2×2×2 metres in metric units by default  (it's also shown under 'dimensions')    Then, with the cube selected, I switch to Edit mode, and enable 'Edge info: Length' under 'Mesh display'    And it shows the cube's measurements, which are 2m on each edge.  Now I use the scale tool in Edit mode, making the edges 2.244m    That's good so far. Changing back to Object mode, the changes can be seen under 'dimension'    However, when I use the scale tool in Object mode, the scale and dimensions also change, but changing back to Edit mode, the measurements shown remain the same      So the question is, why does the scale tool work differently and have different effects in Ojbect mode and Edit mode? Also, how can I enter the desired size of my cube manually to get an accurate result, without using the scale tool in Edit mode, and without changing the scale ratio in object mode? Sort an array without rewriting a key Doesn't Radagast care about trees? In the book The Two Towers, Treebeard refers to Gandalf as "the only wizard that really cares about trees".  But in Fellowship of the Ring, we met the wizard Radagast the Brown, whose special focus is on animals, especially birds.  Of course, animals aren't trees, but it is difficult to imagine a person loving animals without also caring deeply about trees - especially when that person loves birds most of all, and so many birds are so  dependent upon trees for their survival.  More generally, Radagast seems like an all-around nature lover, and this too suggests that he "really cares about trees".  This leads me to imagine several possibilities:   Treebeard doesn't know Radagast (this seems unlikely - they have both been around for thousands of years, so surely they have bumped into each other at some point)   Treebeard forgot about Radagast, possibly because he was annoyed at Saruman and a bit angry at the time    Radagast actually doesn't care about trees    Is there some other alternative I have overlooked, or is one of the options I mentioned correct?  Or does Tolkien never address this apparent problem? I have a char in c#:  char foo = '2';   Now I want to get the 2 into an int.  I find that Convert.ToInt32 returns the actual decimal value of the char and not the number 2.  The following will work:  int bar = Convert.ToInt32(new string(foo, 1));   int.parse only works on strings as well.    Is there no native function in C# to go from a char to int without making it a string?  I know this is trivial but it just seems odd that there's nothing native to directly make the conversion. Is there a HTML opposite to ? Is there a tag in HTML that will only display its content if JavaScript is enabled? I know &lt;noscript&gt; works the opposite way around, displaying its HTML content when JavaScript is turned off. But I would like to only display a form on a site if JavaScript is available, telling them why they can't use the form if they don't have it.  The only way I know how to do this is with the document.write(); method in a script tag, and it seems a bit messy for large amounts of HTML. I am looking for a way to add some string to the beginning of every line (same string for every line). Not something customizable but rather something that will be easy to remember and available on every POSIX-compliant platform (and every shell as well). If $m_1 , m_2, \cdots m_n$ are natural numbers where at least one of them is not a perfect square, then how do I prove that the sum $$\sqrt{m_1}+\sqrt{m_2}+ \cdots + \sqrt{m_n}$$ is irrational? I'm hoping to prove this using methods from pre-calculus level algebra. Holomorphic function has at most countably zeros Let $f$ be holomorphic in a domain $U$, then $f$ has at most countably zeros.  How can I prove this statement? I have seen it in Sheng Gong  explicitly, but without any indications. Proving that if $V$ is an inner product space and $U_1, U_2$ are subsets, then $U_1 \subset U_2$ if and only if $U^{\perp}_2 \subset U^{\perp}_1$ I have the following reference:  @MISC{EX2012,   author = {{S}ingle {A}uthor {O}rganization},   year = {2012},   title = {Example} }   A citation for this is breaking after "Author", but extending beyond the margin, as shown in the following example layout in the PDF:  Demo text demo text demo to margin Demo text which cites it (Single Author Organization, 2012) and flows over the margin.   How can I solve this? I am using natbib and citing with \citep{EX2012}. I have to resit a calculus exam and for some reason set proofs were never my best friend...  Anyway, on a practice exam I encountered the following proof:  $$A\cap(B\cup C) = (A\cap B)\cup(A\cap C)$$  When I draw a Venn-diagram it seems quite obvious but I couldn't manage to write the proof down properly.  If someone could help me, that'd be great! The title says it all, just wondered if accessing the iOS will count towards your consecutive visited days. Does it mean neither a muslim nor a pakistani anymore? Or it means muslim and ex pakistani. I will be very thankfull if you people kindly elaborate this for me. c++ get registry key returns only one char How to disable automount in nautilus's preferences I am using Ubuntu 11.10 (64 bits) and I do not want to mount automatically USB thumb drives in my system. I tried the command dconf-editor and gconf-editor but there isn't the icon to disable it in nautilus preferences (apps|nautilus|preferences|media_automount).  Thanks.