We know that GR and QM are both valid and verified and yet for some reason they just don't want to go together. We say QM describes the microscopic while GR describes the macroscopic. I was thinking it might be simpler than that. Perhaps the reason these to do get along is because they truely are disparate phenomena.  You can't have a particle or event with out a point in spacetime in which it occurs, but you could have a point in spacetime where nothing exists, and no event happens (beyond observing that there is nothing there).   Then GR describes where things happen and how  spacetime is affected once an event does occur, while QM describes the particle's composition and behaviour. To put it another way.  Spacetime which GR describes provides the frame of reference for paticles and force carriers described in QM.  Then it would seem that the reason both are correct and yet seemingly incompatible is that, despite the interplay between the two theories,  they really do discribe two disparate (though interacting) "phenomena" .   Sounds like a nice theory but I have to admit it lacks coroboration.   Is there literature  into Space Time soley as an independant yet interacting frame of reference for Quantum phenomena rather than trying.to explain spacetime as a quantum phenomena?
It is well known that quantum mechanics and (general) relativity do not fit well. I am wondering whether it is possible to make a list of contradictions or problems between them?  E.g. relativity theory uses a space-time continuum, while quantum theory uses discrete states.  I am not merely looking for a solution or rebuttal of such opposites, more for a survey of the field out of interest.
I've recently gotten into The Flash TV show, and so I've been reading about his powers. What I don't understand is why his typical rogues pose a threat - it seems like there should be very little limit to his powers.  He can go back in time, so if he loses a battle or the bad guys do something, he can go back and preempt it. In the new 52, he can all but predict the immediate future, so he can see bad things that are going to happen and stop them. He can phase matter through matter, or let matter pass through him. This means he is all but immune to weapons fire.  I haven't read enough of the old comics so I don't the know challenges he's had. For a guy who can't be attacked, can time-travel and can race around the globe several times in a minute, I can't imagine there is much that could pose a threat. poll() failed, context incorrect? - Example: bpy.ops.view3d.background_image_add() I keep on getting context errors in the Blender Python API.  I don't understand the issue of the context in the API, how do I know which is the correct context?   Thanks! Create user ID `root` to force `gedit` to create user configuration file When using sudo powers and calling gedit the top level menu with File Edit View Search Tools Documents Help is missing.  If I create user ID root and sign in once and call gedit will it create the necessary user configuration files that might fix this?  Will this also make the annoying error messages go away whenever I use sudo, gksu or pkexec as a regular user with elevated privileges togedit ?  Will there be other benefits with Nautilus and other Gnome derivative Ubuntu applications?  NOTE: by sudo powers you can google pkexec gedit 3.5k hits, gksu gedit 40k hits or sudo gedit 500k hits. I'm in the minority using the first method but I believe it will become the standard in Ubuntu 17.04.    June 12, 2017 Update Here are a list of errors you get when using pkexec gedit:  (gedit:13003): Gtk-WARNING **: Calling Inhibit failed: GDBus.Error:org.freedesktop.DBus.Error.ServiceUnknown: The name org.gnome.SessionManager was not provided by any .service files  ** (gedit:13003): WARNING **: Set document metadata failed: Setting attribute metadata::gedit-spell-enabled not supported  ** (gedit:13003): WARNING **: Set document metadata failed: Setting attribute metadata::gedit-encoding not supported  ** (gedit:13003): WARNING **: Set document metadata failed: Setting attribute metadata::gedit-position not supported   On this  there is a commitment to fix these distracting messages as of June 5, 2017. No indication is given for when the fix will be upstream nor if the functionality will be implemented or the error messages will simply disappear.  Note the bug report was filed over a year ago and over that time it only effects 18 people. Many questions already ask about this topic ( , , etc.) and their answers vary, but they always give exceptions to the apostrophe-s rule, for example:      6.24 The general rule for the possessive of nouns covers most proper nouns, including most names ending in sibilants."   Examples they give include Kansas’s, Ross’s land, and Jones’s reputation. Exceptions include Jesus’  and Moses’.  Which names does this apply to?  Is the Aeneas’  form correct, or is it Aeneas’s instead? "An hour" or "a hour" Atomic Physics: stimulated emission I'm studying a chapter about atomic physics right now but there's thing I just don't seem to understand. When stimulated emission occurs, there's an incoming photon which stimulates the atom to go an energy level lower with the result that a new photon gets emitted.  Can someone explain the reason why the incoming photon stimulates the atom to emit a second one? To me it seemed more logic for the atom to absorb the photon and go an energy level up. There seems to be a phenomenon which I don't know about. Ubuntu 18.04 Dock mouse hover tooltips - how to disable? I need to know if it is possible and how to disable the Ubuntu 18.04 Dock tool-tips for mouse hover the pinned application. Simple programs with tutorials for beginners in graphic design? How to prevent LaTeX from hyphenating the entire document? I can't find where I can remove any kind of hyphenation and just have LaTeX just do a line break.  edit: Honestly speaking I just don't like to read hyphenation anywhere and that's the only reason why I wanted to remove it. It is a matter of style, probably unexpected in LaTeX.  The document has only a summary in a different language and I used the language packages to hyphenate properly. Create a directly-executable cross-platform GUI app using Python How does the Higgs mechanism work? I need a DSLR camera with a barcode scanner for on-site tours photography, which means it needs to be untethered! The image would have to contain the barcode scanned information in the image metadata or in the name itself.  I've seen solutions like, Foolography and a $2600 Canon Studio Edition launched in 2010. But I'm not sure of either those products!  So I'm asking the gurus here how I can get this working, which camera would I need and any accessory necessary?  I'm trying to recreate something like I saw the on-site volume photographers do in Disney's parks. What should I look for when buying a used bicycle? I'm moving to a city where I can ride a bicycle to the grocery store, coffee shop etc. I want to purchase a decent used bicycle. I'm leaning towards a bike that's in between a "10-speed" or road-bike and a mountain bike. What should I look for when choosing a particular bike?  I've never purchased a used bicycle. Other than classifieds (e.g., Craigslist), what types of places can I look? What other issues should I consider, such as size, visual appearance, leaking tires, etc.? How can I make sure it's not stolen? I always thought water sources were called taps in kitchens, bathrooms etc, but a Google search only returned outdoor taps.  So my question is, what are indoor taps really called? Like this one: Problem with option border of class standalone I tested a MWE given in question . Following the documentation (page 9) I used the class option border={left right bottom top} with left=right=top=0pt and bottom=20pt (20pt only to show the effect here).  With the version 2012/09/15 v1.1b of standalone and the following MWE I get no 20 pt margin at the bottom of my picture.  What is the problem?  MWE:  \documentclass[% % border=1pt   border={0pt 0pt 20pt 0pt} %left right bottom top ]{standalone}% http://ctan.org/pkg/standalone \begin{document} $2^5 = x_5 \times y^8$ \end{document} Computing the Galois group of $x^4+ax^2+b \in \mathbb{Q}[x] $ I want to compute the Galois group of some polynomials, but I want to see some examples first. For example this proposition could be helpful. I don't know how to prove it &lt;.&lt;  Let's consider a polynomial $f(x)= x^4+ax^2+b \in \mathbb{Z} $. Let $ \pm\alpha , \pm\beta$ denote the roots of $f(x)$. Note that $f$ is irreducible iff $\alpha^2, \alpha\pm\beta \notin \mathbb{Q}$. So let's suppose that $f(x)$ is irreducible. Let's denote $G$ the galois group of $f$ (the Galois group of the splitting field $\mathbb{Q}(\alpha,\beta)/\mathbb{Q}$)  $i)$ $G\cong V$ the Klein 4-group iff $\alpha\beta \in \mathbb{Q}$  $ii)$ $G\cong \mathbb{Z}_4$ iff $\mathbb{Q}(\alpha\beta)=\mathbb{Q}(\alpha^2)$  $iii)$ $G\cong D_8$ the dihedral group of order 8, iff $\alpha\beta \notin \mathbb{Q}(\alpha^2)$  I need help with the proofs of this propositions... Well I'm very lost with the computation of Galois group, some care must be exercised, I don't have it. For example I know that Galois group acts transitively, in the sense that $u\in K/F$ a galois extension, the other roots of the minimal polynomial of $m_u(x)\in F[x]$ are precisely the elements $ \sigma(u)$ , where $\sigma \in Gal(K/F)$. And clearly any automorphism, is determined by only the value of a basis. In this case we are working on $\mathbb{Q}(\alpha,\beta)$, so I have to know the values of both. But I have to respect the algebraic relations involving $\alpha , \beta$ I proved that in $i),ii)$ $\mathbb{Q}(\alpha,\beta) = \mathbb{Q}(\alpha) $ So I have to know the values on $\alpha$.   My first question is: If in both cases $i),ii)$, I have an extension of degree 4 (so $|G|=4$) I have to map $\alpha$ to determine the automorphism, but I have also to map $\alpha$ to all of it's four roots. Why the galois group in this case are different?  My second question is about $iii)$ I have no idea How to attack it. Prove $a^\alpha b^{1-\alpha} \le \alpha a + (1 - \alpha)b, \; a,b > 0,\; 0 < \alpha < 1$ I'm just going to throw this out there, but Google indexes Stack Overflow really quickly For example, I  after using Google to try to find an answer. I then turned back to Google and did a search for  and it was already the first result! Similar searches also put my question on the first page, usually in the top 5!  This is insanity. Did I get lucky and post just before an indexing? Is the popularity of SO leading to Google indexing extremely frequently? Or is Jeff using some kind of crazy SEO? MacTeX - TeX Live Utility broken after 2015 update I have the following strange message.  The repository at ftp://ftp.oleane.net/pub/CTAN/systems/texlive/tlnet  has TeX Live 2015, but you have TeX Live 18446744073709551615  installed. You need to switch repositories in order to continue.   How can I fix this ? Pop up option are not popping up after snipping the area