If one were to run/drive/fly along the earth's surface (by this I mean tangential to the Earth) at escape velocity (about 7 miles per second), would that person escape the gravitational pull? If not, at what speed would this happen?
We know the escape velocity from the Earth is 11.2km/s. Isn't it the velocity required to escape from earth if we go normal to the surface of earth? i.e while we derive the formula for the escape velocity from earth we never consider the slanted motion of the object. So when we launch a rocket we need to use very less value of velocity compare to escape velocity to escape from earth because rocket follows a slanted path so curvature of earth has an effect?  If what I said above is right, then how we can say escape velocity is 11.2 km/s?
Google chrome is reading characters backwards Let $\{K_n \}_{n \in \mathbb{N}}$ be a collection of sets, where $K_n = [n, \infty)$. Why is $\bigcap_{n \in \mathbb{N}} K_{n}$ empty? This question is related to Exercise 2.15 in Baby Rudin, in which the reader is instructed to "[s]how that Theorem 2.36 and its Corollary become false (in $R^1$, for example) if the word 'compact' is replaced by 'closed' or by 'bounded.'"  The relevant theorem and corollary are as follows:  Theorem 2.36: If $\{K_{α}\}$ is a collection of compact subsets of a metric space $X$ such that the intersection of every finite subcollection of $\{K_{α}\}$ is nonempty, then   $\{K_{α}\}$ is nonempty.  Corollary: If $\{K_{n}\}$ is a sequence of nonempty compact sets such that $K_{n}$ contains $K_{n+1},  (n = 1, 2, 3, ...)$, then   $K_n$ is not empty.  My Question: I realize this question and similar ones have been asked elsewhere on MSE, but I've yet to see a straightforward (to me, at least) answer to my question specifically. Usually, for the "closed" part of the exercise, the following collection of closed sets, $\{K_n \}_{n \in \mathbb{N}}$ is used:  $$K_n = [n, \infty), n \in \mathbb{N}.$$  For, the intersection of every finite subcollection of ${K_n}$ is clearly nonempty. Indeed,  $$ \bigcap_{i=1}^{m} K_{n_{i}} = [N, \infty) $$  where $N = \max\{n_1, n_2, ..., n_m\}$.  Then, the assertion is made that   $$ \bigcap_{n=1}^{\infty} K_n = \emptyset. $$  However, I don't see how the same argument can't simply be used, i.e., that, for example, $N \in  \bigcap_{n=1}^{\infty} K_n$ (or maybe, say, $n+1$). Intuitively, this certainly makes sense, I'd say. For, given the archimedean property, it seems that as $n$ approaches infinity, we can always find an $l$ in each increasingly smaller set such that $n &lt; l &lt; \infty$; and so $l \in  \bigcap_{n=1}^{\infty} K_n$.  What is it exactly that I'm misunderstanding or overlooking here? Black screen after installation of Ubuntu 18.04 Are there any reserved words in SQLite? I'm messing around with python for the first time.  I'm making my own changes to the interface, just because..  How can I move the text inside the buttons down and to the left? The left image is what I have now and the right one it's what I want to do..  Please have in mind that I have zero python knowledge. But I'm willing to learn.. How can I network two Ubuntu computers, so that they can "see" each other at an IP address? Curious badge bug I saw that it has been already reported that also they have earned courious badge but the badge has not been given. but their answers say that they must wait a day and the badge will be awarded.  In my case its 8/5 and it was 5/5 long time ago and I have never received a message telling that I have earned it. its just telling me that the next badge to be awarded is Curious badge.  this is my profile: Trying to Remember a Book that explored evolution of Dinosaurs to intelligence and then encountering humans Many, many years ago, I read a book where dinosaurs were assumed to have suvived the K-T event (or it never happened), and they evolved to intelligent species that used not only language (which combined sound, posture, and colour changes on their skin) but also used technology.  In the series, a human is captured or somehow gets integrated with one of the evolved dinosaur groups.  Again, from a very faint memory, the dinosaurs had a level of technology that would be about middle ages, and the humans were much more analogous to American Indian.  That's really all I can recall about the book, and I am trying to find it for my daughter to read.  Can anyone help me out? What is the best solution for database connection pooling in python? I have developed some custom DAO-like classes to meet some very specialized requirements for my project that is a server-side process that does not run inside any kind of framework.    The solution works great except that every time a new request is made, I open a new connection via MySQLdb.connect.    What is the best "drop in" solution to switch this over to using connection pooling in python?  I am imagining something like the commons DBCP solution for Java.    The process is long running and has many threads that need to make requests, but not all at the same time... specifically they do quite a lot of work before brief bursts of writing out a chunk of their results.  Edited to add: After some more searching I found  which looks decent, but as I'm relatively new to python I guess I just want to make sure I'm not missing a more obvious/more idiomatic/better solution. I would like to know where gravity gets its energy to attract physical bodies?  I know that the law of conservation states that total energy of an isolated system cannot change. So gravity has to be getting its energy from somewhere, or else things like hydropower plants wouldn't be able to turn the power of the falling water into a spinning rotor.  Just to be clear, Lets create an example:  Lets say we have two objects with equal mass close to each other. So gravity does its job and it pulls each other closer, this gets turned into kinetic energy. This is where I'm lost. According to the law of conservation energy can't be created or destroyed and the kinetic energy comes from the gravitational pull so where does the gravitational pull gets its energy.  If that energy isn't being recycled from some where else then that means you have just created energy, therefore breaking the law of conservation. "the 90s were the best decade ever" or "the 90s was the best decade ever"  "the 90s" and "decade" are both referring to the same singular period of 10 years, so "was" seems to make more sense. "90s were" rolls off the tongue better though. $\pi$ can be represented as $C/D$, and $C/D$ is a fraction, and the definition of an irrational number is that it cannot be represented as a fraction.   Then why is $\pi$ an irrational number? I rooted my Dream/G1 last night and finally gave up on modding it (not for good mind you, but for the moment) and opted instead to just restore it to factory settings via Settings &gt; SD card &amp; phone storage &gt; Factory data reset, which did solve all the problems I was having with multitasking (and not being able to answer it, etc.)  Curiously, I still seem to have root on the phone, despite having reset it. I'd love to understand how that is possible! Superuser Permissions is the only non-stock app still on the phone, and I'm still able to use su to gain root privileges from adb shell. Is this because BusyBox installs to my SD Card?  My phone works just fine, so this is hardly critical, but the whole exercise was/is about knowing my phone better and this is most def. a mystery. Thanks! I have been reading Men With Brooms for a few days. I read a sentence which did not make any sense to me, so I landed here to get some help on it. I have pasted the sentence from the novel. Please go through it and let me know your valuable feedback on it.  An excerpt from the novel (Men With Brooms: A Sweeping Epic, paperback 2002, a novelization by Diane Baker Mason):     Gordon was about to walk away from the Impala when he saw it stop and his son get out. So it was real the boy had come.   As per my opinion it should have been:     Gordon was about to walk away from the Impala when he saw it stopped and his son got out. So it was real the boy had come.   I have two questions here:   Why did the writer use stop and get instead of stopped and got? As she is telling us a story which happened in the past. Let's say the writer is telling us her mind's situation and she used the present tense for it but why did she use stop and get instead of stops and gets? Add a binary to my path I have an executable. I want to execute the executable in terminal with name only like other commands.  I can put my executable in /usr/local/bin or I could add its PATH to ~/.bashrc. Both will work.  What is better?  Is there  any difference? I got quite some trouble trying to prove this.  $$\sum_{k=m}^{n}(-1)^k\binom{n}{k}\binom{k}{m}=0, n&gt;m\geq 0$$  I tried using $$\binom{n}{m}\binom{m}{k}=\binom{n}{k}\binom{n-k}{m-k}$$ and then changing the summation boundaries as $k=0, n=n-m$, but that took me nowhere... I would really appreciate help. Thank you. Question about the Riemann-Lebesgue Lemma proof Ok, so one of the formulations of the Riemann-Lebesgue Lemma says: $$ f\in L^1(\mathbb{R}) \implies \hat{f}(\omega)\to 0\;\mbox{ when } \;|\omega|\to\infty.$$  I get all the steps of the proof, except the one which says that if $f$ is an arbitrary integrable function, it may be approximated in the $L^1$ norm by a compactly supported smooth function $g\in L^1$. My question is: Why? How do you know that for all $\epsilon&gt;0$, and for all arbitrary function $f\in L^1$ exists a compactly supported smooth function $g$ so that $||f-g||_{L^1}&lt;\epsilon$? The "proof" can be found in many places, but this step can be found in Wikipedia How to open a particular port in ubuntu? My SoulSeek client Nicotine+ checks my open ports during initial configuration and promts that the one port number it needs is closed, cutting me off frmo about 50% of the users. Is there anyway I can open that particular port for the application to use?  RUnning ubuntu desktop 13.04. I have not manually installed any firewalls, but not sure if its included in the default installation. $\lim_{x\to 0} \frac{\sin x - x}{x^2}$ without L'Hospital or Taylor What's a concise way to check that environment variables are set in a Unix shell script?