Prove Spin of a massless particle $S_z=\pm1$
Why is the $S_{z} =0$ state forbidden for photons?
How do I count attendance in Excel? Hi there! I'm looking for a help drawing this diagram. Any ideas? How do I copy Word tables into Excel without splitting cells into multiple rows? I have data in a Word table that includes line and paragraph breaks. When I copy the data into Excel, it splits each line and paragraph I want into multiple cells. How do I copy the data to Excel and keep the breaks? I lost my .keystore file? When Jedi lose parts of their body, does their midi-chlorian count and strength in the Force diminish? From what I understand, midi-chlorian count is a strong indicator of ability in the Force (though there are other factors as well). So it seems like when Anakin loses his arm or Luke loses his hand, their midi-chlorian counts (and thus their Force ability) should slightly diminish.  Is this the case? How do I create a very long delay with Redstone? I am new to dslr's and got a nikon 3000 with 18-55 lens as a gift.  I already see some limitations with the lens for walking about or on trails.  So my question is being new should I go with a 55-200 or 55-300 or is there another step before I go with a telephoto lens. Promote tag wiki creation for new tags Stack overflow links not working Greatest and Least Resistance and Current Characteristics of Parallel vs Series circuits Which type of circuit would have the greater resistance?  Which type would have the greater current? and Why?  My book says that parallel has the greater resistance than current as parallel wiring if thought as water pump tubes has greater resistance during water flow.  Contrary to my book, if I make up numbers to solve for which has the greater resistance, i find that  series has greater resistance.  Equivalent resistance of 2 Ohm resistor in series is greater than that of 2 resistors with 2 ohms in parallel. I I have a laptop which I'm going to return due to battery defects. As I have already configured everything on this laptop, I'd like to migrate the installation on the new laptop (when I'll get it). The one to replace has a 128 GB eMMC, and two USB 3 ports. So, I was thinking to   Boot from a Linux live USB from port 1 Make an image with dd of the eMMC, saving it to a external HDD on port 2 Do the reverse on the new laptop   My question is, will it work fine with Windows? Does migrating this way have any issues? Would I be able to restore the installation if the new laptop is a different model with at least 128 GB? ARMA lag selection for ARMA-GARCH models Why doesn't C3PO recognize Leia in R2's recorded message? I'm planning to buy a new Android phone and I'd like to be able to transfer the progress I have made at several games to the new device, so I won't have to play all the levels again from scratch.  I currently have an HTC Desire and will buy an HTC Evo 3D.  There's probably no simple/general solution to this.  But I was wondering if anyone did something similar and could provide some advice (e.g. where to look for files that might hold game progress information). I want to create buffer polygon(with curved edges) from  points like this using ArcGIS for Desktop.   distance toward North from a point 5, toward South 1.5, toward west 1, toward East 2.   all this distance is attached as attribute in point in different fields. Elastic net penalty I have a question about the elastic net penalty as implemented in glmnet in R compared to the original paper by Zou and Hastie (2005). In glmnet the penalty is listed as   $$ (1-\alpha)/2||\beta||_2^2+α||\beta||_1. $$  but in the paper it is  $$(1-\alpha)||\beta||_1 + \alpha||\beta||_2^2.  $$  Does anyone know where the factor $\frac12$ some from? (Never mind the fact that the $\alpha$'s were swapped between the two parameterisations.) In both cases the penalties are multiplied by $\lambda$, but what are the mathematical/technical arguments for not using a simple convex combination of the lasso and ridge penalties? Disable Tabbing in Firefox 3, Chrome 4 and IE8? Tabbed Browsing may be nice for reading news sites in one sitting, but I still think they are a usability nightmare if you need to keep the page open for a long time, e.g., for testing it while developing or as a reference for something.  The nice thing about the Windows Taskbar (before Windows 7 ) is that it's easy and natural to remember where things are. I can have 30 tabs in it, but because I know what each one is, I know where I have to click to open something - it's the most efficient way of working I've encountered so far.  Sadly, Tabbed Browsing completely breaks this efficiency because it is not possible to specifically click on a tab in the taskbar, I have to click on the browser, search the tab and then click it, which means at least 2 clicks.  Long story, short question: Is there an extension or setting to completely disable tabbing on Firefox 3, Chrome 4 and Internet Explorer 8 and have one Window/Taskbar entry for each open page? I know that in Chrome I can just drag a tab out of a Window to create a new one, but if there is a general way, that would be easier.  Edit: IE8 conveniently offers an option for that: Tools - Options - Tabs - Enable Tabbed Browsing. Need help in proving that $\frac{\sin\theta - \cos\theta + 1}{\sin\theta + \cos\theta - 1} = \frac 1{\sec\theta - \tan\theta}$ We need to prove that $$\dfrac{\sin\theta - \cos\theta + 1}{\sin\theta + \cos\theta - 1} = \frac 1{\sec\theta - \tan\theta}$$  I have tried and it gets confusing. I seem to have screwed up something that allows you to inset evenly, I think I have tried every combination of settings in inset and pivot center and even is far from even.  I tried uninstalling and re installing blender 2.71 and get the same result.  The image attached is a simple default cube that I tried to inset evenly.  I have also attached the blend file link  help?? I'm about to fly from Istanbul to Seoul and I have a useful amount of Turkish Lira (TRY) left but I don't have any South Korean Won (KRW) to pay for the metro to my hostel when I get there.  Several times in the past I've ended up being stuck with currencies that are very difficult to exchange in the country I've arrived in.  Can I buy KRW at the airport in Istanbul?  (I've also asked , since Stack Exchange questions are meant more for the long tail than just for the original asker.)