Energy & Mass of a Photon
Does $E = mc^2$ apply to photons?
Non in front of hyphenated adjective What's the simplest way to wrap extruded text around a cylinder? What's the simplest way to wrap extruded text around a cylinder that has a specific radius (for example, the label on a can of baked beans)?  I've tried using the Simple Deform modifier, but that (a) doesn't allow you to choose a radius and (b) requires the text to be converted to a curve.  I'm trying to model a cylinder with radius of 30, which has a line of embossed text that runs around the curved side, facing outward.  Thanks! Looking for the name of a post apocalyptic/sci-fi tv show or film Every once in a while this starts nagging me, I have really no idea and not much to go on so here goes...  A man wearing a blue? uniform walks into a town that looks abandoned and empty and all covered in dust.  The skies are brown/dirty with no sun.  He goes into the upstairs of one of the houses. He stops at I think a fireplace, examines something, or it’s like he’s remembering something.  Then downstairs in the street, a man/person wearing rags/robes with bandages covering his face starts banging on a fire hydrant with a stick/pipe. More people in bandages/robes start appearing, there's a chase in the town. I don't remember much but he's chased into wastes? through a gully or ditch and then a vehicle (only really remember that it was steel in colour) shows up and a woman comes and shoots one or two of the people chasing him.   That’s about all I remember. I was about 6 or 7 maybe and it was afternoon maybe a little later.  I thought maybe Star Trek, but after searching I don't think it is. I think it might be 80's, maybe early 90's. I think it's sci-fi rather than post-apocalyptic. I need to calculate the Cramer Rao lower bound of variance for the parameter $\theta$ of the distribution $$f(x)=\frac{1}{\pi(1+(x-\theta)^2)}$$   How do I proceed I have calculated $$4 E\frac{(X-\theta)^2}{1+X^2+\theta^2-2X\theta}$$  Can somebody help I read this sentence on an educational website:     Now times have changed and you are ready for situations involving forces in two dimensions.   Shouldn't there be a comma before and, since the subject of the sentence has changed (things vs. you)?      Now times have changed, and you are ready for situations involving forces in two dimensions.   What is the exact comma rule for joining two clauses with and? It seems that I'm missing something about this.  First of all, the series is convergent: $\lim_{n\rightarrow\infty}\frac{2^{-n-1} (n+1)^2}{2^{-n} n^2}=\frac{1}{2}$ (ratio test)  What I tried to do is to find a limit of a partial sum $\lim_{n\rightarrow\infty}S_n$ as follows: $S_n=\frac{\frac{1}{6} n (n+1) (2 n+1)}{\frac{1-\left(\frac{1}{2}\right)^n}{2 \left(1-\frac{1}{2}\right)}}$. Still, the limit is $\infty$ and I'm clearly doing something wrong. How to prove $3^\pi>\pi^3$ using algebra or geometry? It's a question of a some time ago test, I've found a way to solve the problem using calculus, but always I've thought that exist a solution with algebra and geometry.  Thank you for your time. Custom question lists: finding questions you can answer How to get Lookup ID from Search API with REST I'm trying to get the ID of a lookup field when using search api. My query looks something like this:  /_api/Search/query?querytext='ListId:12345678-1234-1234-1234-123456789012'&amp;selectproperties='Title,Company'   Where Company is the lookup field, in a specific list.  The result looks like this:  &lt;d:element m:type="SP.KeyValue"&gt;   &lt;d:Key&gt;Company&lt;/d:Key&gt;   &lt;d:Value&gt;Some company&lt;/d:Value&gt;   &lt;d:ValueType&gt;Edm.String&lt;/d:ValueType&gt; &lt;/d:element&gt;   I have created a managed property which looks like this: system of ode with non-constant coefficient matrix Proving 'Law of Excluded Middle' in Fitch system Automatic line breaking of long lines of text? Here, it is just a example. I have a line:  aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa aaaaaaaaaaaaaaaaaaa   Now, I want to let LaTeX automatically wrap the line according to the width of the text block/margins. Remotely changing hard drive boot order, windows 7 I have one workstation chassis with two hard drives.  Depending on which one I boot from, I get one of two different operating systems: both are windows 7, but they have different static IPs, serve totally different purposes, etc.    The workstation has a modern asus motherboard, core i7 intel CPU, 32 GB ram.   Is there a way to remotely change which hard drive is booted from on a reboot?  Both systems have remote users, and i'd like a solution that is more elegant than being physically present and selecting boot order manually. I want to programmatically create a new column in an MS Access table.  I've tried many permutations of ALTER TABLE MyTable Add  MyField DECIMAL (9,4) NULL; and got:      Syntax Error in Field Definition   I can easily create a number field that goes to a Double type, but I want decimal.  I would very strongly prefer to do this in a single ALTER TABLE statement and not have to create a field and then alter it.   I am using Access 2003. Can two different planes share the same flight number? Recursively copy files from one directory to another I have all my music in a folder /media/kalenpw/MyBook/Music/ABunchOfOtherFoldersWithFilesInside. I want to copy all of the mp3s to /media/kalenpw/HDD/Music so I used:  cp -R /media/kalenpw/MyBook/Music/*.mp3 /media/kalenpw/HDD/Music   however this only copied the mp3s in the root music folder and did not open any of the artist subdirectories and copy those files.  I was under the impression -R would recursively copy all the files. How can I achieve said goal? Wiki-tag edit error is non-descriptive I've been editing some wiki entries on the new Expatriates site, and started to get the following error:    When I go to a normal post, I see what is presumably the proper explanation:    Can the Wiki Tag edit error be updated to show a more meaningful error message? If in a topological space only finite subsets are compact sets, is it then the discrete topological space?   Thank you. Copy existing property from e.g. Properties window to a custom panel So if I have this custom panel in the 3D view, is there a way I can take a property from for example the properties window and paste it onto my panel below the "text" prop, without creating a new property?  The reason I do not want to create a new property is because I want them to share all data, such as values, keyframes, drivers etc.        bl_info = {     "name": "",     "description": "",     "author": "",     "version": (0, 0, 1),     "blender": (2, 70, 0),     "location": "",     "warning": "",      "wiki_url": "",     "tracker_url": "",     "category": "" }  import bpy  from bpy.props import (StringProperty,                        BoolProperty,                        IntProperty,                        FloatProperty,                        FloatVectorProperty,                        EnumProperty,                        PointerProperty,                        ) from bpy.types import (Panel,                        Operator,                        AddonPreferences,                        PropertyGroup,                        )   class inouse_Settings(PropertyGroup):      my_bool = BoolProperty(         name="Enable or Disable",         description="A bool property",         default = False)     class UV_OT_my_panel(Panel):     bl_space_type = 'VIEW_3D'     bl_idname = "UV_OT_my_panel"     bl_label = "Custom"     bl_category = "Custom"     bl_region_type = 'TOOLS'      def draw(self, context):          scn = context.scene         mytool = scn.inhouse         layout = self.layout          col = layout.column(align=True)         row = col.row(align = True)         row.prop(mytool, "my_bool", text="Text")       def register():     bpy.utils.register_module(__name__)     bpy.types.Scene.inhouse = PointerProperty(type=inouse_Settings)  def unregister():     bpy.utils.unregister_module(__name__)     del bpy.types.Scene.inhouse  if __name__ == "__main__":     register() Soving a Complex Integral along a circle