Conveyor animation for Powerpoint presentation
Rigid body simulation not interacting with objects that have an array modifier
Add warning when changing display name The policy on changing one's display name :  only one display name change is allowed every 30 days  However, there is no warning whatsoever when actually changing one's display name.  Thus, it came as quite a bit of a shock to me when I found out today that I might be stuck as &quot;Unicorns are Yummy&quot; on Stack Overflow for the next freakin' month. I would like to recommend that a warning be added to the &quot;Edit Profile&quot; page to warn people. Or, at least make the policy concerning display name changes more obvious. Workaround I was able to change my display name back (phew!) by copying my profile from Meta Stack Overflow. I still think a warning should be implemented, though. Forecast total for a year given monthly time series I have a monthly time series (for 2009-2012 non-stationary, with seasonality). I can use ARIMA (or ETS) to obtain point and interval forecasts for each month of 2013, but I am interested in forecasting the total for the whole year, including prediction intervals. Is there an easy way in R to obtain interval forecasts for the total for 2013? Food in the Star Wars Universe? Are the foods in the Star Wars Universe the same as ours'? Do they have strawberries or potatoes or something? I know that they might have some food other than the food that we also have, but I'm wondering if they have any food like ours'. Using multiple wildcard parameters with arcpy.ListFeatureClasses I know there has to be a way to do this but I'm having trouble figuring out how to do so. I would like to create a list of feature classes to perform operations on however, I want to have the list contain feature classes which have 2 separate and distinct file name identifiers. The code would look something like:  FCS = arcpy.ListFeatureClasses("X_*" OR "*_Y")   I know OR is incorrect however, is there some way to do this without having to re write code to work with the second wildcard. Thanks for helping gout, i know there is a selection method in the Select By Attributes which allows for multiple wildcard use using the OR statement. I will give this question a little context. Firstly, as I understand it, as soon as I "close the switch" on a circuit, electric current pretty quickly establishes a steady state where, at any given cross section along a wire, the average kinetic energy of that slice is both constant and equal anywhere along the wire. (Please correct me if I am misunderstanding).   If the average kinetic energy is constant anywhere throughout the wire in the circuit (which confuses me, as I would think that the electrons should all accelerate after exiting the resistor since they are no longer being impeded as much), that means that the average velocity is constant. So, in the example of a simple circuit with a battery of v Volts and a resistor of o Ohms, my question is the following:  Because a 'voltage drop' is known to occur across the resistor, what type energy is being "traded" to generate the heat that radiates from the resistor? I would think that the reflexive answer is "electrical energy"...hence the VOLTAGE drop (the sacrificed energy is clearly not kinetic, as the velocity is constant everywhere). However, I find this confusing. Does this mean that if I had a positive test charge, it would be easier for me to bring it to the beginning of the resistor as compared to bringing it to the end of the resister?     Further, if the correct answer IS "electrical energy", why exactly DOES electrical energy get "dissipated" as the electrons pass through the resistor? I always here the comment Oh! It's because all the electrons are running into densely packed crap which impedes their flow but that to me sounds like a reason for their KINETIC energy to be reduced. However, clearly that's not the case. So, ultimately, I guess the real question is:  **What goes on in the resistor that is literally removing electrical energy **. I am sure that this is a quantum mechanics question, but my quantum mechanics knowledge is not terribly strong. If I could get an answer that is devoid of crazy wave function equations, I would greatly appreciate it. Thanks! A finite $p$-group cannot be simple unless it has order $p$ I am to trying to prove this theorem: A finite $p$-group cannot be simple unless it has order $p$.  I have this:   Let $G = P$ and $|G|=p$; then there exists $N$, a normal subgroup of $G$ by Lagrange's theorem, such that $|N| \mid |G|$ so, $|N|= |e| = 1$ or $|N| =  p$  If $|N|=p$ so $N=G$.  But I don't know how I can prove the part in the case of $|N|=|e| = 1$  Is my start correct? Evaluate the integral $\int_{-1}^1\frac{dx}{(e^x+1)(x^2+1)}$. Evaluate:      $$\int_{-1}^1\frac{dx}{(e^x+1)(x^2+1)}$$ Is JavaScript a pass-by-reference or pass-by-value language? How do you concatenate characters in java? Concatenating strings would only require a + between the strings, but concatenating chars using + will change the value of the char into ascii and hence giving a numerical output. I want to do System.out.println(char1+char2+char3... and create a String word like this.  I could do   System.out.print(char1); System.out.print(char2); System.out.print(char3);   But, this will only get me the characters in 1 line. I need it as a string. Any help would be appreciated.  Thanks Proof problem: Show that $n^2-1$ is divisible by $8$, if $n$ is an odd positive integer. I want to ask a question about modular arithmetic. I know, that modular multiplicative inverse exists only if modulo and integer are relatively prime. I want to know, are there any ways of division in modular arithmetic, if modulo and integer aren't relatively prime? I tried to find info about that, but failed. Number of normals from a point to an ellipse From a typical point $P$ inside an ellipse, how many points $Q_i$ on the ellipse have $PQ_i$ normal to the ellipse?  Someone asked me at school many years ago but I don't think I worked it out. Calculus of variations -- how does it make sense to vary the position and the velocity independently? I live in Ethiopia and the government blocks all urls with the word "proxy" in them. I couldn't use that word in the title above because that would make the url contain the word proxy.   When I apt-get upgrade I get errors because some packages like libproxy1, libproxy1-plugin-gsettings, libproxy1-plugin-networkmanager, python-libproxy all contain the p word.  Therefore, it is all blocked. I tried putting the urls into proxy sites, but they all just returned to their home page.   Are there any other solutions? How does IPv4 Subnetting Work? Do electrons really perform instantaneous quantum leaps? This is not a duplicate, non of the answers gives a clear answer and most of the answers contradict.  There are so many questions about this and so many answers, but none of them says clearly if the electron's change of orbitals as per QM can be expressed at a time component or is measurable (takes time or not), or is instantaneous, or if it is limited by the speed of light or not, so or even say there is no jump at all.  I have read this question:      where Kyle Oman says:     So the answer to how an electron "jumps" between orbitals is actually the same as how it moves around within a single orbital; it just "does". The difference    is that to change orbitals, some property of the electron (one of the ones described by (n,l,m,s)) has to change. This is always accompanied by emission or absorption of a photon (even a spin flip involves a (very low energy) photon).   and where DarenW says:     A long time before the absorption, which for an atom is a few femtoseconds or so, this mix is 100% of the 2s state, and a few femtoseconds or so after the absorption, it's 100% the 3p state. Between, during the absorption process, it's a mix of many orbitals with wildly changing coefficients.      where annav says:     A probability density distribution can be a function of time, depending on the boundary conditions of the problem. There is no "instantaneous" physically, as everything is bounded by the velocity of light. It is the specific example that is missing in your question. If there is time involved in the measurement the probability density may have a time dependence.   and where akhmeteli says:     I would say an electron moves from one state to another over some time period, which is not less than the so called natural line width.     where John Forkosh says:     Note that the the electron is never measured in some intermediate-energy state. It's always measured either low-energy or high-energy, nothing in-between. But the probability of measuring low-or-high slowly and continuously varies from one to the other. So you can't say there's some particular time at which a "jump" occurs. There is no "jump".     where annav says:     If you look at the spectral lines emitted by transiting electrons from one energy level to another, you will see that the lines have a width . This width in principle should be intrinsic and calculable if all the possible potentials that would influence it can be included in the solution of the quantum mechanical state.   Experimentally the energy width can be transformed to a time interval using the Heisneberg Uncertainty of   ΔEΔt>h/2π   So an order of magnitude for the time taken for the transition can be estimated.     So it is very confusing because some of them are saying it is instantaneous, and there is no jump at all. Some are saying it is calculable. Some say it has to do with probabilities, and the electron is in a mixed state (superposition), but when measured it is in a single stable state. Some say it has to do with the speed of light since no information can travel faster, so electrons cannot change orbitals faster then c.  Now I would like to clarify this.  Question:   Do electrons change orbitals as per QM instantaneously? Is this change limited by the speed of light or not? In a group $G$, if for all $a,b,c\in G$, $ab=ca\Rightarrow b=c$, then $G$ is abelian Let $G$ be a group. If for all $a,b,c\in G$, $ab=ca\Rightarrow b=c$, then phow can I prove that  $G$ is abelian? My router can do port-forwarding based on MAC addresses. That is, a specific MAC will get a specific IP, for which I can configure a set of ports to be forwarded. In order to easily change that set of ports, I'd like to have different connections in the Network manager.  How do I change the MAC address for a network connection? I've seen many of the solutions on the topic, all posted in this site. But I haven't seen any of them mentioning Apple's adapter,   I have that, which was used to connect to my old MacBook Pro 2013.   Now, I'm assuming that all I need is to connect the Mini DisplayPort to an adapter, such as  (as mentioned in one of the posts) and the USB cable to a USB-C adaptor.   Is this correct? I want to leave my Mac awake overnight so it syncs 4GB of data from Dropbox. I need to prevent the machine from going to sleep because that pauses the Dropbox sync  I've been using  to keep the computer awake, but it also keeps the computer unlocked which is insecure.  I need a method to keep my Mac awake (so that Dropbox can sync overnight) but also locked (so no one can read my email). It'd be great if this method also turned off the screen (to preserve power), but honestly that's not even 100% necessary.