First law states that energy can neither be created nor be destroyed. So how did the big bang gathered so much energy to expode?
Did the law of conservation of energy apply to the earliest moments of the Big Bang? If so, what theoretical physics supports this?   I hear that Einstein's theory of relativity disputes the law of conservation of energy- so does that mean the law is false, or only some aspect of it?
I want to use a very long USB cable to place a webcam in a different room. The maximum length that I found was five meters.   What is the maximum length of a USB cable? What is the maximum length achievable when using USB extension cables? How to get the ASCII value of a character How do I get the  value of a character as an int in ? I would like to see the icons in the 'Hot Network Questions' right panel clickable, leading to the homepage of the site where the question comes from.  It would make it more comfortable to switch to the site when you want rather to visit it than to see that specific "hot" question. Directory size calculation difference I need to get the size of directory in terminal for signing purposes. I'm using following command:  du -s /path/to/dir   I'm multiplying the result by traditional UNIX block size (512 bytes) and get actual directory size in bytes. However, the Finder's "Get Info" dialog window shows the size slightly smaller than the one calculated with the terminal command. And it seems that it's reproducible on any folder/bundle. What am I missing? Prove that $$1+\frac{1}{3}+\frac{1\cdot 3}{3\cdot 6}+\frac{1\cdot 3\cdot 5}{3\cdot 6 \cdot 9}+.........=\sqrt{3}$$   $\bf{My\; Try::}$ Using Binomial expansion of  $$(1-x)^{-n} = 1+nx+\frac{n(n+1)}{2}x^2+\frac{n(n+1)(n+2)}{6}x^3+.......$$  So we get $$nx=\frac{1}{3}$$ and $$\frac{nx(nx+x)}{2}=\frac{1}{3}\cdot \frac{3}{6}$$  We get $$\frac{1}{3}\left(\frac{1}{3}+x\right)=\frac{1}{3}\Rightarrow x=\frac{2}{3}$$  So we get $$n=\frac{1}{2}$$  So our series sum is $$(1-x)^{-n} = \left(1-\frac{2}{3}\right)^{-\frac{1}{2}} = \sqrt{3}$$  Although I know that this is the simplest proof, can we solve it any other way someting like defining $a_{n}$ and then use Telescopic sum.  Thanks. Russian babel and chemformula Send values from one form to another form From Geneva airport to Lausanne station On September 4, I will be arriving in Geneva by airplane at approximately 11 AM. After that, I need to go to Lausanne. I have two questions:   Do I need to buy a train ticket online, or can I buy it directly at the station without any problems? (Problems such as: the trains are always full, it's not permitted to buy a ticket etc.) Moreover, are the tickets only for a specific train or it is like "you can board any train from Geneve to Lausanne with this ticket"? How do I get from the airport to the Geneva train station (as low a budget as possible, I guess walking is not an option though), and how much does it cost?   I'd appreciate answers from people who have been there, but if you're able to find an exhaustive link from any website that's okay too. Let $\alpha = \frac{1+\sqrt{-19}}{2}$. Let $A = \mathbb Z[\alpha]$. Let's assume that we know that its invertibles are $\{1,-1\}$. During an exercise we proved that:     Lemma: If $(D,g)$ is a Euclidean domain such that its invertibles are $\{1,-1\}$, and $x$ is an element of minimal degree among the elements that are not invertible, then $D/(x)$ is isomorphic to $\mathbb Z/2\mathbb Z$ or $\mathbb Z/3\mathbb Z$.   Now the exercise asks:     Prove that $A$ is not a Euclidean Domain.   Everything hints to an argument by contradiction: let $(A, d)$ be a ED and $x$ an element of minimal degree among the non invertibles we'd like to show that $A/(x)$ is not isomorphic to $\mathbb Z/2\mathbb Z$ or $\mathbb Z/3\mathbb Z$.  How do we do that? My problem is that, since I don't know what this degree function looks like, I don't know how to choose this $x$!  I know that the elements of $A/(x)$ are of the form $a+(x)$, with $a$ of degree less than $x$ or zero. By minimality of $x$ this means that $a\in \{0, 1, -1\}$. Now I'm lost: how do we derive a contradiction from this? SFDC DKIM Setup - Production or Sandbox? Cannot figure out this via SFDC documentation. Need someone who have setup this before to advise.  Basically we want to enable DKIM for our SFDC org. In testing Sandbox and production, the from email address is using the same email domain. For example, "test@abc.com" for sandbox and "contact@abc.com" in production.   Question: shall we setup DKIM in both sandbox and production or just need to setup in production since sandbox and production are actually using the same domain "abc.com"? What's the difference between a Long Term Support Release and a Normal Release? What are the differences between an Ubuntu Long Term Support release (LTS) and a normal release? Hartshorne Theorem 8.17 Why don't we include $\rho g h$ in a hydraulic jack below? 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. Why is "improve this question / answer" shown to anonymous users instead of "edit"? If I browse a site as an anonymous user, instead of "edit" I see: "improve this question / answer".        I don't get it, are anonymous users considered to be kinda dumb and don't understand "edit"?  Why to reword this action? In .NET, which loop runs faster, 'for' or 'foreach'? Detach (move) subdirectory into separate Git repository What is that "1 view" which automatically appears after submitting a question? Are the questions submitted on SO and other SE sites initialized with 1 view, or does the first view belong to the user who posted it?  Why is a question given a free first view? It just appears, as soon as the question is published. Idiom or expression criticizing people who ignore you right after getting what they wanted/ were after Split string containing command-line parameters into string[] in C# I have a single string that contains the command-line parameters to be passed to another executable and I need to extract the string[] containing the individual parameters in the same way that C# would if the commands had been specified on the command-line. The string[] will be used when executing another assemblies entry-point via reflection.  Is there a standard function for this? Or is there a preferred method (regex?) for splitting the parameters correctly? It must handle '"' delimited strings that may contain spaces correctly, so I can't just split on ' '.  Example string:  string parameterString = @"/src:""C:\tmp\Some Folder\Sub Folder"" /users:""abcdefg@hijkl.com"" tasks:""SomeTask,Some Other Task"" -someParam foo";   Example result:  string[] parameterArray = new string[] {    @"/src:C:\tmp\Some Folder\Sub Folder",   @"/users:abcdefg@hijkl.com",   @"tasks:SomeTask,Some Other Task",   @"-someParam",   @"foo" };   I do not need a command-line parsing library, just a way to get the String[] that should be generated.  Update: I had to change the expected result to match what is actually generated by C# (removed the extra "'s in the split strings)