E.g. why do we experience gravity all the time, but on an atomic scale, the gravitational forces are so small?
Why is gravity stronger than other forces at the macroscopic level, yet weaker than other forces at the quantum level? Is there an explanation?
How can I find out which apps I have already downloaded on my iPhone? When you attempt to download an app that costs money, you will not be charged if you already bought the app. After you press buy and enter your iTunes password, it will say "You have already purchased this item. To download it again for free, select OK."  The problem is that I deleted hundreds of apps from my phone, some of which were paid for. Later on I might find an app I like but notice that it costs money. It might be an app I had already paid for, or an app which I got when it was free.  How can I know if I tap the buy button if I will be charged for the app or not?  In other words, how can I know if I owned a previous version of an app before? Getting error using JMeter behind a proxy I am new to JMeter and trying to run a test from behind a corporate proxy. I read on the same from apache site and followed the same process so as to run the test. However, i am still  unable to record a test from behind the proxy.      This message always appears after pressing on 'Start' recording:     After that, I have changed apache port to 8000 as in below and made it different      This time after pressing on start was this message I remember reading a series when I was around 7th or 8th grade about aliens who had taken over Earth by putting metal caps on people when they were "entering adulthood" to control them (not direct control, but it would keep them from rebelling). There was a faction of people who able to escape and had fake caps and would save teens who were about to be capped.  The main protagonist was a teen boy who was a boxer (or training to be a boxer or something). The aliens would hold tournaments for the humans and whoever won would be "worthy" to serve as personal slaves to the aliens.     The protagonist won and was able to get inside to try and learn more about the aliens from the inside. I'm having a bit of a trouble with the below question     Given $G$ is an undirected graph, the degree of a vertex $v$, denoted by $\mathrm{deg}(v)$, in graph $G$ is the number of neighbors of $v$.   Prove that the number of vertices of odd degree in any graph $G$ is even. What suggestions should I make when reviewing a poorly written paper? Since I need a break from the reviewing...  Often in my field I review papers from researchers in Asia (reviews are not double blind) which are poorly written. By poorly written, I don't mean that the prose is not pleasing to the eye, that there are problems with how the writing flows, or that there are innocuous typos or spelling mistakes. Instead, the grammar used by the authors differs seriously from normal English, and often produces significant changes in the meaning of sentences.  Usually such papers are ultimately readable, but one has to go back and re-read sentences or paragraphs several times to infer the meaning (and this is with strong knowledge of the research area!), so I generally won't reject a paper solely for this reason. However, I would feel remiss in my duties as a reviewer if I didn't instruct the authors to improve this aspect of the paper. I'd like to provide helpful advice for the authors without just giving them a laundry list of the errors.   Typically I highlight a few places where I had significant trouble understanding what they actually meant to say, and suggest seeking a professional editor before publication.   Are these reasonable things to suggest?   What other suggestions can I make? maximum of two uniform distributions I have a question. Let's suppose that the two random variables $X1$ and $X2$ follow two Uniform distributions that are independent but have different parameters:  $X1 \sim Uniform(l1, u1)$  $X2 \sim Uniform(l2,u2)$  If we define X3 as the maximum of X1, and X2, i.e., $X3 = max(X1, X2)$, what kind of distribution would it be? It is certainly not a uniform and I can calculate the cumulative probability, i.e., $p(X3 &lt;= a)$, because $p(X3 &lt;= a) = p(X1 &lt;= a) p(X2 &lt;= a)$. But, I wonder if there exists any density function that can model X3. Quite often, the phrase "x for x's sake" is used in English, and so one could describe someone as being "argumentative for argument's sake" to describe someone who is arguing for the sake of arguing.  However, is there an adjective that means the same thing?  For example, it could be used in the context:     I don't want to be [X], but [argument...]   ... indicating that your argument is necessary and not intended to irritate. What are the meaning and possible origin of "word!" and "word up"? Series about proxy space battles via implanted computers in kids The premise of the story is that there are 2-3 main coalitions on Earth and they fight over resources in the edges of the solar system with spaceships that are controlled from Earth by kids with computers in their heads.  If I recall correctly:   The main character's name is Tom, he starts out by conning people at some sort of gambling arcade before he is found and recruited by the "army" The Pentagon in the US has a super tall tower built in the courtyard called The Spire where most of the three books take place. The reason they need kids for this has something to do with brain elasticity and putting computers in adults causes them to go mad. All the cadets are super dismissive about learning how to program their computer aside from one girl who is super good at it. The best fighters from each side of this conflict were something of superstars, but everyone else was kept completely anonymous for their protection. There were at least 3 books last I knew, released circa 2011-2014 The third book ends with Tom being the first astronaut to Mars. The first book had a green cover, the second was yellow, and the third was red. Though I might have the order wrong. Prove $\vdash \neg(\square F\land p)$ in $KD$ Where did folder "merge" or "keep both" go in OS X 10.9 Mavericks? Before Mavericks one could hold the ALT key and move a folder "A" onto a folder "B" where already an "A" existed. In this case Mac OS X asked in Lion if I want to merge - or on Mountain Lion if I want to keep both (which was also a merge).  I can't find this option in Mavericks.  Did Apple remove this useful feature?  Any hints?  (And yes: I own ForkLift, which can do it - I just sometimes still prefer the Finder). Joining lots of small polygons to form larger polygon using PostGIS? How do I set up a "secure" open resolver? This is a  about securing public DNS resolvers   Open DNS servers seem pretty neat and convenient, as they provide IP addresses that we can use consistently across our company regardless of where they are located. Google and OpenDNS provide this functionality, but I'm not sure that I want these companies to have access to our DNS queries.  I want to set up something like this for use by our company, but I hear a lot about this being dangerous practice (particularly in regards to ) and I want to make sure that we do this right. What things do I need to keep in mind when building this type of environment? When I try to connect to servers or join up on lan worlds in Minecraft it says "Failed to Login : Invalid session (Try restarting your game)". Multiplayer used to work fine but now keeps coming up with this error. Can anybody help? How to exit from an application which doesn’t exit on press back button? Is it possible to obtain AES-128 key from a known ciphertext-plaintext pair? I have a file, which was encrypted with AES-128 in ECB mode. I know the format of the original file and know that all files in this format have the same headers. So, I have an encrypted block and the original block.  Can I get the encryption key, using this information? I need to get a history of which processes have run on my Windows machine, and when they were run.  However, I cannot use any third-party software, as I cannot guarantee that it will always be running.  Is there any way to get this information only using Windows built-in functionality? How can I convert a vector to a cell array? I've got two tables:  TableA ------ ID, Name  TableB ------ ID, SomeColumn, TableA_ID (FK for TableA)   The relationship is one row of TableA - many of TableB.  Now, I want to see a result like this:  ID     Name      SomeColumn  1.     ABC       X, Y, Z (these are three different rows) 2.     MNO       R, S   This won't work (multiple results in a subquery):  SELECT ID,        Name,         (SELECT SomeColumn FROM TableB WHERE F_ID=TableA.ID) FROM TableA   This is a trivial problem if I do the processing on the client side. But this will mean I will have to run X queries on every page, where X is the number of results of TableA.   Note that I can't simply do a GROUP BY or something similar, as it will return multiple results for rows of TableA.   I'm not sure if a UDF, utilizing COALESCE or something similar might work? Two of my friends are getting married. They're both huge Doctor Who geeks, and actually met through a DW RPG. Their wedding invitation contained a very subtle DW reference (you wouldn't have been able to tell unless you were very familiar with the show yourself.)   Doctor Who's been running long enough that there are quite a few nice quotes for basically every occasion in life. I was hoping someone would know a nice wedding-related one, or maybe one about love, that I could include in a wedding card?