Does a router have a unique MAC address? Is it detectable by a website?
Is your MAC address revealed when you hit up a website?
Lets say I have a  creature that says "Whenever another creature enters the battlefield under your control, you may gain 1 life." and I currently have all 4 of them in the battlefield. Then I cast another creature and : Do I get 1 or 4 life? Does that effect trigger for every priest or just once? thanks for help Can someone please explain this weird Pygame importing convention? I am trying to create buffers around the Hurricane Sandy path I created in QGIS (points are lat/long).   I have both points from each day she was tracted and the line I created from it with Points2One.   When I go to make buffers around either the line or the points, the buffer takes up the whole screen. Its all just one color.   I have made buffers before but from data I did not create.   Right now all of my projections are set to WGS 84 EPSG 4326. Script to remove Yellow(or any color) from layers panel? Polar Plot x and y ticks and units Prove that $\prod_{k=1}^{n-1}\sin\frac{k \pi}{n} = \frac{n}{2^{n-1}}$ Using $\text{n}^{\text{th}}$ root of unity  $$\large\left(e^{\frac{2ki\pi}{n}}\right)^{n} = 1$$  Prove that   $$\prod_{k=1}^{n-1}\sin\frac{k \pi}{n} = \frac{n}{2^{n-1}}$$ I accidentally disabled my admin account.  After I login to another account I found I can not get admin rights, because all admin accounts on my computer are disabled.  I clicked on 'run as administrator' but only see a smart card choice (all the admin accounts are disabled so no choice provided)    I don't want to re-install my OS, help!    Details:  I have account A on my computer.    I got a new computer so I want to give the old one to my mother.    Creating a new user account B for her and disable account A.    Logout and restart.    Successfully login B, now I found I could not get admin rights because no account choice is provided.    More informations about my machine:  OS is Windows 10 and my admin account is a Microsoft Account.  I have an arch-linux installed on my computer and dual-boot it using GRUB, so maybe I can not use safe mode. Bounds for $n$-th prime In  I have found that the bounds for $n$-th prime is given by, $$n(\ln n+\ln \ln n)&gt;p_n&gt;n(\ln n+\ln \ln n-1)$$ for all $n\ge6$. Are there even stronger bounds for the $n$-th prime?   If possible (of course if the answer is affirmative) in the answer (or comment) please give the link of the paper in which it first appears. How does the ternary operator work? Greek numbering What is the relative speed of two near-light speed particles headed towards each other? I understand that nothing can move faster than light due to time dilation. I want to build upon my understanding of Einstein's theory of Special Relativity, so I came up with this hypothetical problem for myself:  If both particles are moving at 0.9c towards each other (according to an observer on Earth), what speed does each particle have relative to the other?  I'm stumped since I am only familiar with Newtonian classical mechanics to solve this (which would be wrong). I am aware of Lorentz' factor $\gamma =\frac{1}{\sqrt{1 - \frac{v^2}{c^2}}}$ and the time dilation equation $t_m = \frac{t_o}{\sqrt{1 - \frac{v^2}{c^2}}}$, but I'm not sure how to apply it in this instance. I'm just looking for a gentle push in the right direction. Edit: My prior research:  This article, ,  talks about the effect of a baseball thrown at 0.9c would have as it traveled towards a batter. This is not what I'm looking for since it doesn't explain the math behind finding the collision speed between two high velocity entities.  This question on Yahoo, , asks a similar question to mine, but no math is involved to demonstrate the calculations behind the reasoning.  This question on Physics.SE, , does not answer my question either. I have not been able to find a similar Physics.SE question which can provide me to clues to my own hypothetical question.  I have also Googled the following phrases:    i. &quot;collision faster than the speed of light&quot; ii. &quot;collision of high speed particles&quot; iii. &quot;lorentz transformation in a collision&quot; iv. &quot;collision analysis at light speed&quot; Atmospheric pressure In FBD doubt Let us say I have a beaker floating in a water tank. Suddenly I put some water in the beaker also. The figure here shows the exact situation   Now I want to draw the FBD of the beaker. I am somehow confused with the role of the atmospheric pressure in drawing the FBD. I thought of two ways of drawing this and I am just unable to figure out which one is right.    Here since the beaker is floating an $F_{buoyant}$ is there in the upward direction which the net mass (beaker+water in beaker) would put its weight downward.  But while solving one question I came to know that total force that a liquid exerts on the bottom of the container is $P_0+m_{liquid}g$ ($P_0$ is the atmospheric pressure). So should the downward force on the beaker be $(M_{beaker}+M_{water in beaker})g+P_0 S$ (S being the base area of the beaker) as in the second diagram down here.    Here the $P_0S$ due to atmospher on the tube gets cancelled by the $P_0S$ exerted by the water in tank on the tube. But what about the $P_0S$ from the water present in the tube? Do the FBD's apply like the one in the new image? I am trying to prove the following identities:  a. $$\sum_{k=0}^n(-1)^k{n\choose k}^2 = \bigg\{^{0 \ \text{if k is odd}}_{(-1)^m{2m\choose m} \ \text{if n = 2m}}$$ b. $$\sum^k_{i=0} {n+i \choose i}={n+k+1\choose k}$$  For part $b$ I know I can use induction. It is clearly true when $k=0$ and then assuming for $k-1$ we get $$\sum^k_{i=0}{n+i\choose i}={n+k\choose k-1}+{n+k \choose k}={n+k+1\choose k} \ ...$$ A get() like method for checking for Python attributes If I had a dictionary dict and I wanted to check for dict['key'] I could either do so in a try block (bleh!) or use the get() method, with False as a default value.  I'd like to do the same thing for object.attribute. That is, I already have object to return False if it hasn't been set, but then that gives me errors like     AttributeError: 'bool' object has no attribute 'attribute' Bonus continent troops in Risk So I have taken over all of Australia and I get 2 extra troops.    My friend then attacks Indonesia from Southeast Asia. When it's my turn I retake control of Indonesia.  Now, do I get 2 more bonus troops since I retook control over the continent? I'm trying to boot Canonical's Azure 16.04 .vhd file in a VirtualBox VM and it hangs at "non blocking pool is initialized".  It works in Hyper-V, so it may only be a bug in virtual box (5.0.20). Evaluating and negotiating a start-up package I've been offered an academic position, and am now in the fortunate, but unfamiliar position of negotiating the offer.  I've seen a few blogs/comments/posts on this process.  However, I have no real idea how to evaluate the offer that's been made.  Coming from the position of a postdoc, the package seems impressive (given that, as a postdoc, my "package" consists of a very modest salary and health benefits).  However, I also realize the importance of maximizing (within reason) my initial offer, as this sets the baseline for, at least, the first few years of my faculty career and could provide support that would prove very important in the initial year or so while I'm trying to obtain grant funding.  In particular, I'm looking for two types of information.  First, what types of startup packages are standard for tenure-track assistant professors of Computer Science at a public RU/VH (i.e. Research) university?  This is just to give me some point of comparison.  Second, what types of changes are reasonable to negotiate?  Can I ask for more summer salary support while still conveying to them my desire to obtain grant funding as quickly as possible?  The offer already includes a reduced teaching load for the first few years --- is it also reasonable to ask for an extra semester off prior to a tenure review?  I understand these are fairly broad questions, but any input or suggestions would be very helpful.  I'm definitely interested in the job; I really liked the department and think it's a great opportunity.  I don't want to alienate anyone by pushing too hard, but at the same time, I want to make sure that I make every reasonable effort to maximize my chances for academic success, which includes maximizing my available resources by negotiating the best startup package I can. Is there a 2D generalization of the coefficient of restitution? The  characterizes a collision in one dimension by relating the initial and final speeds of the particles involved,  $$C_R = -\frac{v_{2f} - v_{1f}}{v_{2i} - v_{1i}}$$   In a 2D collision, the velocity can be split into components parallel and perpendicular to the "plane of collision" (the plane tangent to the two objects' surfaces at their contact point), and the equation above applies to the perpendicular components of the velocities only. One could write  $$\begin{pmatrix}v_{2f\shortparallel} - v_{1f\shortparallel} \\ v_{2f\perp} - v_{1f\perp}\end{pmatrix} = \begin{pmatrix}1 &amp; 0 \\ 0 &amp; -C_R\end{pmatrix}\begin{pmatrix}v_{2i\shortparallel} - v_{1i\shortparallel} \\ v_{2i\perp} - v_{1i\perp}\end{pmatrix}$$   My question is, is it useful (i.e. does it produce a more accurate description of realistic 2D collisions) to generalize that matrix? Perhaps by allowing the top left element to be unequal to 1, or allowing nonzero off-diagonal elements? Or is there some nonlinear relation that works better?  As usual, if you know of any relevant published research, references would be much appreciated. Is using Gravatar a security risk? This has been . It is unfortunate the accepted answer is so far from reality.   There are some facts:    's MD5 hash is an unsalted MD5 hash of an email address. A 3rd party could harvest every MD5 hash for every user's email on Stack Overflow.  The 3rd party could store all the hashes in a lookup table Email addresses are usually of a very particular format The attacker could start with a brute force of @gmail.com followed by @yahoo.com, etc. The attacker has the advantage that he/she could attack a huge set of emails in one go. So instead of needing to brute force every email individually the attacker can brute force in bulk.   The algorithm is quite simple, calculate a "random" MD5, look it up in the lookup table.       Is Gravatar a big enough security risk to warrant caching images locally?     Examples:    Someone could harvest about 50k email addresses quite easily and shoot off a bogus promotion from Stack Overflow to all the users. A spammer/stalker/generic evil guy can tie you identity to all the rest of the sites that use Gravatar. Does one need to adjust for multiple comparisons when using MANOVA? There are 10 dependent variables and 2 groups. When I wanted to compare 10 dependent variables between two groups, I performed MANOVA.  I wonder if there is a multiple comparison problem in that case. Should I have performed Bonferroni correction because of 10 dependent variables? Or is Bonferroni useless because MANOVA just does analysis once?