Is the gravity between objects other than celestials observable?
Can the effects of a person's mass upon the local gravitational field be detected and measured remotely?
Arrows linking table cells I'm currently trying to add arrows in my synthetic division example to show people clearly how synthetic division works. I'm working on Overleaf.   The code for my synthetic division right now is:  \begin{tabular}{c |r r r r r}     &amp;1&amp; 4 &amp; -1&amp;16&amp;-20\\   1&amp;&amp; 1 &amp; 5 &amp; 4&amp;20\\   \hline    &amp;1 &amp;5 &amp; 4 &amp; 20 &amp;\rule{3pt}{16pt}\;0\\   \end{tabular}   How would I add arrows to this? For instance, a down arrow going from the first 1 to 1, then an upwards arrow pointing right from 1 to 1, then an arrow pointing down from 1 to 5, etc. Basically I would like to add arrows that look like this: Argument in "thebibliography" I was reading the explanation about  and was totally confused:     The thebibliography environment has an argument which should be a string at least the length of the widest entry label in the source list. Instead of using the numbers generated by the environment as entry labels, you can specify your own by using an optional argument to \bibitem, but remember to increase the length of the argument to the thebibliography command.    What does "widest entry label" mean? Practically, what should I put as the argument in   \begin{thebibliography}{?}   or is the argument not necessary? I applied for a standard visitor visa to the UK for seven days. I earn £278/month and have been working at the same organization for more than a year. I have saved up enough funds for the trip and I attached bank statements to prove it. The ECO refused my visa stating:      I note that you stated that your trip to the UK will cost you £1100, this is approximately 4 times your monthly income. I do not find it credible that you spend this amount on a trip.   I am a single woman, with no financial responsibilities and I saved up for this trip because I really wanted to visit the UK.  How do I prove to the ECO and the authorities that spending £1,100 for my trip wouldn't have caused me any financial harm neither would I have had to access UK government funds?    Another concern of mine is that if I reapply without the partial funding of my father or get sponsored by a different person, does the amount given by my father previously cause hindrance in my visa application?  Won't they still reject it on the basis of my pay being too insignificant? Can you not sell/destroy buildings? So I've started playing Gathering Storm, built a bunch of coal plants and now Global Warming is out of control mainly because of me. I've been trying to remove these power plants, but I haven't found any option to sell/destroy or even replace these buildings.  Is there seriously no way to do this? Give an example of a continuous function $f : [0, ∞) \mapsto [0, ∞)$ such that $\int_{0}^{\infty}f(x)dx$ exists but $f$ is unbounded. Give an example of a continuous function $f : [0,  ∞) \mapsto [0, ∞)$ such that  $\int_{0}^{\infty}f(x)dx$ exists but  $f$ is unbounded.   I have been thinking about this. And I have come to the conclusion that I will need to construct a function, $f$, such that $f$ is a sequence of triangles of increasing height, but decreasing base. I obviously need $f$ such that both the height of the triangles, and sum of the bases tends to infinity. But I also need that the $\sum (\text{height} \times \text{base}) \leq \infty $ Homebrew putty installation does not make the putty command recognisable I would like to instal  with use of Homebrew. I'm performing the following command:  brew install putty   which gives the seemingly correct output:  ==&gt; Downloading https://homebrew.bintray.com/bottles/putty-0.67.el_capitan.bottle.tar.gz Already downloaded: /Users/thisuser/Library/Caches/Homebrew/putty-0.67.el_capitan.bottle.tar.gz ==&gt; Pouring putty-0.67.el_capitan.bottle.tar.gz 🍺  /usr/local/Cellar/putty/0.67: 11 files, 1.5M   However, the putty command is not recognised:  thisuser-541/41:~$ putty -bash: putty: command not found Deleting a suspicious malware (imklaunchagent) in Mac I have a MacBook Pro (macOS Mojave) laptop and have recently noticed a suspicious process in Activity Monitor with this name : imklaunchagent    I checked this folder: /System/Library/Frameworks/InputMethodKit.framework/Versions/A/Resources/imklaunchagent and it seems imklaunchagent and its related files cannot be removed. I tried to remove it via Terminal and this message showed up: "Operation not permitted". However, in "Security and Privacy" of "System Preferences", I chose Terminal to have full disk access, still can't delete the file and the same message appears.  I installed the free version of Combo Cleaner and it detected other viruses, none of which are imklaunchagent. Is imklaunchagent a malware? How can it be deleted? How to float until on left (or right) page? I have two sideways tables that I want on two facing pages so the reader can turn the entire book and read them both in one turn. For the moment I keep moving them around to keep them on facing pages. Is there a way I can make the first one float until it's on a left page and then place the other one right after? Or perhaps some similar way to automatically get them on the same spread? TeXnicCenter & Adobe Reader DC How can I disable landscape mode in Android? Torus object stretched in array curve modifier I have a chain object. And i have a curve it follows. I got it to work for following curve, but chain object is not circles but both parts are more like stretched circles (ovals). Object i made with 2 toruses one rotated 90 degrees and then joined them together. I tried single torus too. But same issue. on a curve it just looks stretched oval. What can be the issue?   Thanks How to remove a vector QgsVectorLayer from QGIS python plugin I managed to add QgsVectorLayer in QGIS through a python plugin, for example:  vl = self.iface.addVectorLayer(uri.uri(), layerName, self.dbConn.getProviderName())   But how can I remove it? Differences between ways to express future actions What are good books for graduates/undergraduates in Astrophysics? There are no book recommendations for Astrophysics here. I will write my own answer, but I am also interested in what are others' views on the question (I will NOT mark my own answer as the best one). su command + authentication failure Android app "Unknown error" when uploading photo Spent a half hour on this. Android 5.1.1 latest version SE app (Play Store won't let me update so latest).   Tried to upload photo into an answer. "Something went wrong".  Did tricks to reduce photo size to 275k -- same.    45k rep on the stack.  Here is the photo..... oh wait.  How do I solve? Which cyan colored line is produced in the Thomson e/m apparatus? Related:   After reading Lisa Lee’s OP on an electron deflection tube, although she had some misunderstandings on its operation, I still believe that her question is still relevant. If one looks at the Thomson e/m tube filled with helium gas (made by ), the tracer light is created by de-excited electrons, not by an electron beam interacting with a phosphor as in Lisa Lee's OP. That is, the accelerated electrons scatters off of a low pressure helium gas and emit a tracer line to follow the electrons path, as shown below.     Now if you look at the bright line spectrum of helium,     One can clearly see that there are two “cyan” color lines around 500 nm. Following in Lisa Lee’s footsteps, there is a series of question one can ask: (1) which line is emitted by the Helium gas atoms? Or are both lines emitted? (2) How can a variable accelerating voltage for the electrons always produce the same tracer line color? In theory, I assume that if I decreased the energy of the electron beam, I could produce red (around 670 nm) or yellow (around 590 nm) tracer lines, but that doesn’t happen. Somehow, it appears to me that the e/m tube is “tuned” just right so that the emitted light is always this “cyan” color. Why? How to disable touchscreen permanently on ubuntu 18.04 "Similar questions" overlaps footer and has no background When I can scroll down far enough to have the hot network questions overlap the footer (because my question is short) there is no background under the text:    Could they either be given a white background: (just disable the transparency option)    Or stop at the footer:      This also happens with the help text on some sites, as per this bug report:     Ubuntu 14.04.1 (Latest LTS Version), . Same problem with  and .  Windows 10 Pro,  and .  (Images linked to screenshot of browser)  My question is different from  because my issue is the lack of background on the footer.   I think there was a site redesign? Two players, $A$ and $B$, alternately and independently flip a coin and the first player to get a head wins. Assume player $A$ flips first.  If the coin is fair, what is the probability that $A$ wins?   So $A$ only flips on odd tosses. So the probability of winning would be $$ P =\frac{1}{2}+\left(\frac{1}{2} \right)^{2} \frac{1}{2} + \cdots+ \left(\frac{1}{2} \right)^{2n} \frac{1}{2}$$  Is that right? It seems that if $A$ only flips on odd tosses, this shouldn't matter. Either $A$ can win on his first toss, his second toss, ...., or his $n^{th}$ toss. So the third flip of the coin is actually $A$'s second toss. So shouldn't it be $$P = \frac{1}{2} + \left(\frac{1}{2} \right)^{2} + \left(\frac{1}{2} \right)^{3} + \cdots$$