first of all I'm not sure if I should post this here or in the astronomy stack. I think biologist are more likely to answer my question. To make it short:  Why when looking for any sort of life on other planets, we keep looking for similar conditions we call "life friendly", like nice temperature, oxygen level, pressure etc...  Is there some rule in biology that says life can only exists under these conditions? Why nobody supposes that evolution did not have enough time yet on our planet to generate other living mechanisms, and that on other planets even if the conditions are not suitable for us, there might be something well evolved through time there. After all if we can conceive electric robots that can survive to radioactivity and to high pressures and temperatures, why nature shouldn't be able to?
I have seen many articles that talk about a star's "habitable zone" as the ring around it which is just the right temperature for planets to have liquid water, which is necessary for life. My question is, why does a planet need to have liquid water in order to sustain life? Who says that extraterrestrial life can't live off of some other kind of sustenance?
Why is the "Arnold Schwarzenegger" terminator referred to by two different product numbers (T-101, T-800)? Convergence of $\sum_{n=1}^\infty{\left(\sqrt[n]{n}-1\right)}$ Should the currently selected item in a combo/dropdown box also be included in the list of choices? For example, you have a combo box which contains 10 elements including the one that is currently selected. When you prompt to drop down the list to choose another, should the currently selected item also be in this list? Particles rotation not working correct Difference between declaring variables before or in loop? ok, ive a class and i pass an object as property.  the object that i pass is a List&lt;X&gt;  in my class im trying to access the Object index by reflection BUT I CAN'T!!!   Example:  this class works i just wrote down the part i want to show you and i need help.  class MyClass {     private object _recordSet;     public object RecordSet     {         get { return _recordSet; }         set { _recordSet = value; }     }      public string Draw()     {         system.reflection.Assembly asem = system.reflection.Assembly.getAssembly(_dataSource.GetType());          object instance;          instance = asem.CreateInstance(_dataSource.GetType().UnderlyingSystemType.FullName);          //to access de Count of my List         int recordcount = int.Parse(_dataSource.GetType().GetProperty("Count").GetValue(_dataSource,null));          //i need to do a          for(int cont = 0; cont &lt; recordCount; cont++)         {             _dataSource[cont].Name; // &lt;-- THIS PART IS NOT WORKING!!! because i cant access the Index Directly.... WHAT TO DO!! ???         }     } } Is there a problem with Beamer in the latest MiKTeX update? This is about MiKTeX Revision 2.9.6360.  Immediately after the latest MiKTeX update, my Beamer files stopped compiling.  When i tried to compile a file that had been working fine I got a Package installation popup saying:  tex\latex\beamer\beamerbasemodes.sty  Is missing.  It is part of the following package  beamer   So i clicked to have it installed.  All that achieved is that i got an error message  ! LaTeX error: File 'beamerbasemodes.sty' not found   I repeated this a few times with minor changes to the file, and then went to the MiKTeX Package Manager to see what parts of Beamer are installed.  It said none were.  Either the update had removed Beamer, or the attempt to install beamerbasemodes on the fly had done it.  So I reinstalled it by hand.  In fact i did this several times in various ways.  It made one difference.  Sometimes the problem package was identified as  translator.sty  In case it would help, I ran Update FNDB and restarted my machine.  Each time I installed Beamer, the Package Manager then reported that Beamer was installed.    But when I tried to compile the file, the same things happened all over.   And when i went back to the MiKTeX Package Manager it reported Beamer is not installed.   Is Beamer now out of date?  Or is this a problem on the new update?  Is there a simple fix i can use? Indent math blocks? I want all math blocks \begin{math} in my document to be intended automatically, like it's the case with \begin{itemize}.   Can anyone please give me a hint on how to do this? Thanks :-) There is a classic problem:  Suppose that $X_1,\ldots,X_n$ form an i.i.d. sample from a uniform distribution on the interval $(0,\theta)$, where $\theta&gt;0$ is unknown. I would like to find the MLE of $\theta$.  The pdf of each observation will have the form: $$ f(x\mid\theta) =  \begin{cases} 1/\theta\quad&amp;\text{for }\, 0\leq x\leq \theta\\ 0 &amp;\text{otherwise}. \end{cases} $$ The likelihood function therefore has the form: $$ L(\theta) = \begin{cases} 1/\theta^n \quad&amp;\text{for }\; 0\leq x_i \leq \theta\;\; \text{for all }i,\\ 0 &amp;\text{otherwise}. \end{cases} $$ The general solution is usually that the MLE of theta must be a value of $\theta$ for which $\theta \geq x_i$ and which maximizes $1/\theta^n$ among all such values.   The reasoning is that since $1/\theta^n$ is a decreasing function of $\theta$, the estimate will be the smallest possible value of $\theta$ such that $\theta\geq x_i$.  Therefore, the mle of $\theta$, $\hat{\theta}$, is $\max(X_1,\ldots,X_n)$.  Here, I do not understand why we cannot just differentiate the likelihood function with respect to theta and then set it equal to $0$?  Thanks! throwing exceptions out of a destructor Most people say never throw an exception out of a destructor - doing so results in undefined behavior. Stroustrup makes the point that "the vector destructor explicitly invokes the destructor for every element. This implies that if an element destructor throws, the vector destruction fails... There is really no good way to protect against exceptions thrown from destructors, so the library makes no guarantees if an element destructor throws" (from Appendix E3.2).   seems to say otherwise - that throwing destructors are more or less okay.  So my question is this - if throwing from a destructor results in undefined behavior, how do you handle errors that occur during a destructor?  If an error occurs during a cleanup operation, do you just ignore it? If it is an error that can potentially be handled up the stack but not right in the destructor, doesn't it make sense to throw an exception out of the destructor?  Obviously these kinds of errors are rare, but possible. I have question about ArcGIS and python script. There are following sample code, So I would like to change Another Field , not OIDFieldName. Please let me know how to change Another Field.  import arcpy import itertools  arcpy.env.workspace = r"C:\path\to\workspace"  base_shapefile = "some_shapefile.shp"  oid_field = arcpy.Describe(base_shapefile).OIDFieldName feature_count = int(arcpy.GetCount_management(base_shapefile).getOutput(0))  for (i, j) in itertools.combinations(range(feature_count), 2):     arcpy.Select_analysis(base_shapefile , "combination_%i_%i.shp" % (i, j), '"%s" in (%i, %i)' % (oid_field, i, j))   These sample code is combination for 5C2. I want to create all combiantions 5C3 , 5C4 , 5C5. Finding the dual basis for the space of polynomials of degree $\leq$ 2 Let $V$ be the space of polynomials of degree at most $2$, with basis $\{1,x,x^2 \}$.Find the dual basis to $\{1,x,x^2\}$.   I know that the dual basis of $\{f_1,f_2,f_3\}$ is the basis $\{f_1^*,f_2^*,f_3^*\}$ where $f_i^*(a_1f_1,\ldots,a_3f_3)$ but I'm not sure how to actually compute the dual basis. How to bond two different internet connections I've only found a recursive algorithm of the extended Euclidean algorithm. I'd like to know how to use it by hand. Any idea? How caret calculates R Squared From the training output below, it looks like R squared is not calculated by the traditional formula 1 - SSE/SST, since lower error rate has lower R squared. So how is it calculated?    colsample_bytree  min_child_weight  RMSE      Rsquared    0.4               3                 16963.39  0.8799191   0.4               5                 16813.24  0.8788395 Using continuous color band for raster legend in QGIS composer legend? I'm looking for a way to insert continuous colour legend for a raster layer.  I managed to create discrete symbols with values along the bar, but I would like to have a continuous bar with some values on the bar, similar to the old plugin "One-Band Raster", that it doesn't work with the QGIS version higher than 1.7  I tried to set in properties->style, where I selected the  Render Type "Singleband pseudocolor" and see the "generate new color ramp" box.  I tried both "Continuous" or "Equal interval". However, in the Composer the legend always is displayed with discrete symbols.  Is there any way that can make QGIS Composer to display a nice continuous band for a raster layer? (Google) Title of page not updated, everything else did My website changed significantly this month.  Amongst the changes was the website's title.  Two weeks ago, I finally used Webmaster Tools and submitted the page.  So far, Yahoo and Bing have updated the title in the search results, but not Google.  I've resubmitted via Webmaster Tools the website, and the bots have crawled the page, and have added "content keywords".  But the title still doesn't match.  The "content keywords" lists many of the words in the new title (but contains keywords of the existing title also).  Must say that 4 of the top 5 key words in the "significance" list are the new title's.  Still, no change.  Any remedies for this problem?  Is adding the "alt" tag for the logo significant enough to trigger the change?  There isn't an appropriate place to put the company name between  tags on the front page.  Any suggestions?  Thanks. 1) "The book 'The Three Musketeers' is a wonderful example of..." Here we have a proper noun, a title that happens to end in a plural, and I have no sense that the verb should be plural. "Musketeers"/is seems proper/natural/correct, and 'are' not at all.   However, such certainty begins to wane in other examples: 2) "'The Heidi Chronicles' is a wonderful example of..." doesn't completely shake my confidence, but it moves the needle, at least a little bit. But, practically speaking, I wouldn't have a second thought about correcting a student who used 'are' instead of 'is'.  Here's the one that really bothers me: 3a) " 'The Basement Tapes' are a wonderful example of..." I don't think this sounds any less proper/natural/correct than 3b) " 'The Basement Tapes' is..." In fact, 3a seems less awkward than 3b.  Why? LaTeX Classes or Styles for Schedules and/or Calendars? Maybe TeX isn't the best for this particular problem, but any teachers out there use a particular class or package to plan lessons?  Right now I'm just using a spreadsheet, but I always find myself wishing there was a 'lessonplan.sty' or 'classschedule.sty' file out there somewhere so I could still use the LaTeX for equations, tables, lists etc.    A bit of searching yielded a few results, but there doesn't seem to be a consensus.  Anyone used any of these:        Any recommendations from anyone on best way to make calendar-based class schedules and/or lesson plans? Suppose I want to know whether $\sqrt{7}\in\mathbb{Q}_5$, or more generally, whether $\sqrt{n}\in\mathbb{Q}_p$ for $n\in\mathbb{Z}$, $p$ an odd prime. What are the techniques for determining this? Am I supposed to "lift" it from $\mathbb{Z}/p\mathbb{Z}$ using Hensel's lemma? Could I see an example?