It is the everyday life in boxing: One boxer gets a smack in the head, cannot do anything for many seconds and then: Victory of his opponent due to a Knockout!   What is the reason for losing consciousness for a short time by e.g. a strong smack in the head?  Are there any neuronal reactions that cause this?
Consciousness is an electrical and chemical interaction in the brain, caused by neurons firing and chemical interactions. How does a mechanical "force" cause this to stop working?  i.e. How does a mechanical action (such as a punch to the head) cause this electrical/chemical system to stop working (leading to unconsciousness)?
Currently, for all my commands that require root access, I have to type them out on a command line.  I would like for the GUI to prompt me to key in my password, when sudo is required, instead of having to type out the commands from command line.  Is there any way to enable this? Previously one version of Ubuntu desktop had this feature out of the box.  This version of Ubuntu (that I am now running) I upgraded from a server installation.  I will add, my user account is already added to sudo group. Thus I can run commands such as sudo gedit or sudo apt-get but I'm not able to install software in the Ubuntu Software Center. How can we recover the Newtonian gravitational potential from the metric of general relativity? The Newtonian description of gravity can be formulated in terms of a potential function $\phi$ whose partial derivatives give the acceleration:  $$\frac{d^2\vec{x}}{dt^2}=\vec{g}=-\vec{\nabla}\phi(x)=\left(\frac{\partial\phi}{\partial x}\hat{x}+\frac{\partial\phi}{\partial y}\hat{y}+\frac{\partial\phi}{\partial z}\hat{z}\right)$$  However, in general relativity, we describe gravity by means of the metric. This description is radically different from the Newtonian one, and I don't see how we can recover the latter from the former. Could someone explain how we can obtain the Newtonian potential from general relativity, starting from the metric $g_{\mu\nu}$? Is it possible to save `bc` command line history? bash has a handy file .bash_history in which it saves the history of commands and on the next execution of bash the history is populated with saved commands. Is it possible to save bc command history to a file in the same way and then load it on startup so that bc history is preserved? I tried reading  and it mentions readline and libedit. From ldd /usr/bin/bc I see mine uses readline and readline has  and read_history functions. Is this functionality implemented in bc or to do it I'll need to patch bc? Revision history suggests that I edited the post body, whereas I didn't I was doing some re-tagging and I noticed that the automatically generated revision comment says that I edited the post body where I only edited the tags. I am unable to figure out simple solution to add "Bookman Old Style"  as a main font in my latex document. I have used below line but does not give me required font.  \usepackage{bookman}   Could not find any Simple correct answer for this. Pl. suggest how to do it.  I am using windows, pdflatex.  thank you Why is the application of probability in  (QM) fundamentally different from its application in other areas? QM applies probability according to the same  as in other areas of physics, engineering, etc.  Why is there a difference?  Naively one would assume one of these possibilities:   It is not the same probability (theory?) It is a matter of interpretation (of the formalism?) Something else?   Many answers (which I am still studying) focus on the fact that the combined probability of two mutually-exclusive events in QM is not equal to the sum of the probabilities of each event (which holds classically by definition). This fact (appears to) makes the formulation of another probability (a quantum one) a necessity.   Yet this again breaks down to assumed independent, if this is not so, the "classic probability" is applicable (as indeed in other areas). This is one of the main points of the question. What does the notation like 8.6e-28 mean? What is the 'e' for? Ubuntu desktop suddenly points to home folder Are  and the  really the same thing?  Not too long ago, Susskind and Bousso uploaded the article "" with the thesis that the many-worlds interpretation and the multiverse of eternal inflation are one and the same thing. The parallel worlds of one are exactly the same thing as the parallel worlds of the other.   First, they claim decoherence can't happen over a complete description of the future light-cone of the measurement. Then, they apply that principle to eternal inflation. Without decoherence, superpositions of nucleating bubbles and metastable vacua can't decohere. According to the anthropic principle, most bubbles have no conscious observers, but an exponentially small minority do. Apply black hole complementarity to causal horizons.  Then, somehow, in a way I can't follow, they combine causal diamond worlds into a global multiverse.  Then they claim decoherence is reversible.  My head is spinning. What are your opinions on this paper? Why does holding something up cost energy while no work is being done? I need to repair my Windows 10 installation. Where can I get a clean ISO (with install.wim, no Install.ESD, so that I can run DISM against the WIM) of the specific Windows 10 build required for this?  In my case, I need the Anniversary update (Build 14393), Creators Update (Build 15063) or Fall Creators Update (Build 16299.15). Movie with "Where do the tubes go?" I'm trying to find a movie with an underground facility with people wearing white suits. The people have been affected such that they show no curiosity. There is one person that does and asks one of his co-workers where a tube leads to.      At the end there is an uprising where everyone gets to see the surface and sunlight.   What is the name of this movie? How to compute the  formula $\sum  \limits_{r=1}^d r \cdot 2^r$? Is the set of all finite sequences of letters of Latin alphabet countable/uncountable? How to prove either? Today in Coding/Cryptography class, we were talking about basic definitions, and the professor mentioned that for a set $A=\left \{ \left. a, b, \dots, z \right \} \right.$ (the alphabet) we can define a set $A^{*}=\left \{ \left. a, ksdjf, blocks, coffee, maskdj, \dots, asdlkajsdksjfs \right \} \right.$ (words) as a set that consists of all finite sequences of the elements/letters from our $A$/alphabet. My question is, is this set $A^{*}$ countably or uncountably infinite? Does it matter how many letters there are in your alphabet? If it was, say, $A=\left \{ \left. a \right \} \right.$, then the words in $A^{*}$ would be of form $a, aa, aaa, \dots$ which, I think, would allow a bijection $\mathbb{N} \to A^{*}$ where an integer would signify the number of a's in a word. Can something analogous be done with an alphabet that consists of 26 letters (Latin alphabet), or can countability/uncountability be proved otherwise? And as mentioned before, I am wondering if the number of elements in the alphabet matters, or if all it does is change the formula for a bijection.   P.S. Now that I think of it, maybe we could biject from $\underset{n}{\underbrace{\mathbb{N}\times\mathbb{N}\times\mathbb{N}\times\dots\times\mathbb{N}}}$ to some set of words $A^{*}$ whose alphabet $A$ has $n$ elements? Thanks! Is there an easy way to change filetype association? After the upgrade to 11.10 I've had the problems that    all music-files would open with banshee, which then crashed all folders would open with konsole   The first problem I  after installation of "ubuntu tweak" "> admin > filetype Associations".. Changed back to totem.  The second was somehow not accessible this way (did not give any possibility to add commands).  I've changed the line "inode/directory=nautilus-folder-hanlder.desktop" to "inode/directory=nautilus.desktop" from "/usr/share/applications/defaults.list" and now everything works fine.  Question: More convenient ways to do that? How did Princess Leia survive this? In the Last Jedi movie, there is a scene where      her spaceship is taken down, Princess Leia is thrown into outer space, and seen floating there, frozen.    However, she manages to survive this, while any ordinary human being couldn't.   How did she manage this? Is this done by using the Force? How to add System.Windows.Interactivity to project? Given a continuous random variable $X$ and the pdf find.... There is a pattern excercise:  First pattern: We have $X$ and the probability density function is usually:  $$ f(x) = \begin{cases}   {ax+bx^2} &amp;  {0\lt x \lt 1} \\   0 &amp; \text{else}   \end{cases} $$  Then we are given $E|X| = 0.6$   And usually asks to find:  a) $P\{X&gt;0.5\}$  b) $Var(X)$    Second pattern:  $$ f(x) = \begin{cases}   {cx^4} &amp;  {0\lt x \lt 2} \\   0 &amp; \text{else}   \end{cases} $$  Where c is a constant. Find:  a) Mean value of $X$  b) Variance of $X$     Third pattern (it's more like a reverse problem):  We are given $Y= \sqrt{X}$, find it's cumulative distribution function (CDF) and  it's probability density function (pdf).    Update:  The third one is transferred to a .  This is not homework. I'm self-studying and in need of some help. Thank you. Run Trigger As A Specific User (or Profile)? Is this possible?  I'm not finding help, Google or otherwise, for this.  Situation:  A trigger runs and cycles through groups of Opportunities.  Some of these Opportunities are Closed Won, and most users of the system are not allowed to Edit Closed Wons (especially the Sales team).  But I need this trigger to be able to touch the Opps (it's fired when the User touches the Account and subsequently a group of Opps under that account gets touched).  It is a VALIDATION RULE blocking them.  Ultimately, I may investigate, if no other option, setting a HIDDEN FIELD on the Opp before updating, then clearing if after, and putting bypass code in the Validation rule.  This is a backup plan.  I'd like to know how to "Run As" a specific profile though.  Anyone have an example of this?  I have three profiles out of twelve that can touch Closed Wons... Restate theorem in separate file I state a theorem in the main body of a document and prove it in the appendix. I use thmtools's restatable environment to restate the theorem there. However, I now need to have my appendix in a separate pdf file (hence a separate tex document). I'm using xr and xcite to get the cross-references and bibliographical references to play nicely.  But the commands created by restatable are not carried. Is there any way to to the restating of the theorem in the appendix in a separate document?  Here's a MWE:  main document: main.tex  \documentclass{article} \usepackage{thmtools} \newtheorem{theorem}{Theorem}  \begin{document}  \begin{restatable}{theorem}{thmcmd}\label{thmlabel} Here is the statement of the theorem. \end{restatable}  The above is Theorem~\ref{thmlabel}.  In this way I can restate it: \thmcmd*  \end{document}   appendix: appendix.tex  \documentclass{article} \usepackage{xr} \externaldocument{main} \usepackage{thmtools} \newtheorem{theorem}{Theorem}  \begin{document}  I can refer to Theorem~\ref{thmlabel}.  But I cannot restate it like this: % \thmcmd*  \end{document}