Airplane on a treadmill
What will happen if a plane trys to take off whilst on a treadmill?
I am trying to set multiple definition queries for one layer based on one field using python.  ie.  I have a City layer with a field that holds the city name.  I want a copy of the layer in an MXD with the Definition query set for each value in the City field.  So essentially, I have one source layer, with a copy of the layer as many times as there are values in the City field.  The query would look like this: CITY = 'Atlanta' Please revisit the CAPTCHA & China issue Back in 2012 when China first blocked all Google services, thereby preventing non-VPN users from proving their non-roboticness, someone quickly opened this thread on Meta:    The consensus at the time was "we can't think of a better way of doing things".  Well, 3 years have passed and China is showing no signs of unbanning Google. Meanwhile, CAPTCHA technology has evolved. Can the SE admins please revisit this situation? People in China without a VPN are completely unable to prove they are not bots. I couldn't even search for the phrase "pgp" on Security.SE without hitting the human verification barrier. Blocking questions is one thing, but searches also? I think that's too strict.  (yes, I wrote this with my VPN) Mysterious contact by advanced aliens; leaves humans insane It'd be great if anyone could remember the source of this short story I only dimly remember, but recall finding quite haunting back in my youth.  I read it maybe 20 years ago in a paperback that probably dated from the '80s.  It begins with the protagonist (a young man) being being woken by a deafening noise coming through his cochlear implant.  He's on a spaceship, and has volunteered to be put in a capsule and fired off to a remote part of the solar system.  Once in place in their capsule, the volunteers are visited by what is (presumably) a highly intelligent alien life-form, and gifted with some artefact containing priceless knowledge, like, for example, the cure for cancer.  The (unexplained) encounter leaves the them completely and irrevocably insane, perhaps terrified out of the minds.  Yet despite this, volunteers still clamour to be chosen for the mission. Why are there scenes that will not render on GPU but will render fine on CPU? I've already tried GPU Rendering and it seem to be twice as fast as the CPU. However I have some situation where tried to render on the GPU, but it doesn't do anything. When I switch to CPU it renders.  I have some fur texture/materials using particle systems. I wonder if that causes the GPU not to render, I'm not really sure. Safari Extension to Manage Tabs? Integral of $\frac{\sqrt{x^2+1}}{x}$ So I have to do the integration of $\frac{\sqrt{x^2+1}}{x}$. Give me a hint. What should I replace? Should I do it with integration by parts? Prove that the dihedral group $D_4$ can not be written as a direct product of two groups I like to know why the dihedral group $D_4$ can't be written as a direct product of two groups. It is a school assignment that I've been trying to solve all day and now I'm more confused then ever, even thinking that the teacher might have missed writing out that he means normal subgroups.  On another thread it was stated (as the answer to this question) that the direct product of two abelian groups is again abelian. If we consider the direct product of abelian subgroups $H$,$K\in G$ where $HK=G$ (for all $g \in G$, $g=hk$ $h \in H$, $k \in K$.) I can't understand why this would imply $g=kh$? It is not stated anywhere that $H$,$K$ has to be normal! But if this implication is correct I do understand why $D_4$ (that is non-abelian) can't be written as a direct product of two groups. But if it's not, as I suspect, I need some help!  We know that all groups of order 4 and 2 are abelian, (since $4=p^2$), but only 4 of the subgroups of $D_4$ are normal:  Therefor I can easily show that $D_4$ can't be a direct product of normal subgroups: The only normal subgroups of $D_4$ is the three subgroups of order 4, (index 2 theorem): $\{e,a^2,b,a^2b\}$, $\langle a\rangle$, $\{e,a^2,ab,a^3b\}$ and the center of $D_4=\{e,a^2\}$ We can see that these are not disjoint. So $D_4$ can't be a direct product of normal subgroups. The reason for this being that the center is non-trivial. But why can't $D_4$ be a direct product of any two groups?  If we write the elements of $D_4$ as generated by $a$ and $b$, $a^4=e$, $b^2=e$, $ba=a^3b$ why isn't $D_4=\langle b\rangle\langle a\rangle$ ? I calculated the products of the elements of these two groups according to the rule given above and ended up with $D_4$, and also $\langle a\rangle$, $\langle b\rangle$ is disjoint...? Why is this wrong? Very thankful for an answer! Checking incoming call in iphone Misleading chat usercard on SE 2.0 chat Journal of Finance Template German '*.bst' How can I remove excess fat from stews or soups without refrigerating? Error When Create Drupal Commerce Product Display I want to write a survey on one emerging research topic in wireless communications (It can be applied to any field!). There are almost 500 papers on this topic as published or in early access. And the publishing rate in this topic is increasing day by day. So, I want to write a survey on this topic keeping in mind that it will get high citation and it will help new scholar who are in struggle with this topic. I found only one survey written by some reputed authors, however it lacks in many ways, like detailed information related to particular direction, it just assembles the papers in a good manner. I want to pick some directions and discuss  important approaches with good connection between them. However, I find it very difficult to proceed with large number of papers. Is there any good way to handle the survey process in a good efficient and quick way? PS. According to me, many people have already started to write this. Show timestamp of a vote in the tooltip when mousing over it I need to install more applications - can I use my external HD (samsung T5) and add an additional applications folder? I have loads of space on it and it the speeds are great. Understanding the "Birthday Problem" I had to take ownership of the special folder C:\Program Files\WindowsApps to fix . The issue is now resolved, so I'd like to reset the permissions to the way they were before I took ownership of the folder.  I reverted NT SERVICE\TrustedInstaller to the owner and removed my account's permission entries:     But I still have full control of the folder and can browse the folder in Explorer without getting the usual warning that I would have to take ownership:     Is it possible to restore the default permissions of this folder? Why is the sum of the digits in a multiple of 9 also a multiple of 9? The sum of the digits in $9 k$ (where $k$ is an integer) is a multiple of $9$: for example   $$9\cdot 1=9$$ $$9\cdot 7=63 \qquad  \text{and } 6+3=9\cdot 1$$ $$9\cdot 11=99 \qquad \text{and }  9+9=9\cdot 2$$  But why? Why are our planets in the solar system all on the same disc/plane/layer? I always see pictures of the solar system where our sun is in the middle and the planets surround the sun. All these planets move on orbits on the same layer. Why? Assume I have many TeX files. For the sake of simplicity, also asssume they are in a single folder or directory.  I want to input all files from within my main LaTeX document. Actually I can create a list of those files using C# in advance.  To enrich my view about LaTeX or TeX, could you tell me whether or not this job can be done only by using pure TeX or LaTeX?