Many articles say that "the coronavirus" — they probably speak of the SARS-CoV-2 — can "remain alive" for so many hours on some surfaces, so many days on some other surfaces. For example, "the virus lives 5 days on glass".  I think that this is a bad choice of word. All these articles speak about the virus SARS-CoV-2 as if it were a living being. But I think it is not a living being. The virus SARS-CoV-2 does not "live" on a glass surface. It just is there.  When a virus SARS-CoV-2 is on an object, what happens to it? If it is not there anymore after 5 days, why? What does time do to a virus?
Given that the majority of biologists do not currently consider viruses to be alive, a virus can never die.  It can, however, get destroyed by long exposures to soapy water, alcohol, and apparently certain frequencies of UV light.  Why is an individual SARS-CoV2 virion not infectious forever?  Or is it?
Lightning aura:iteration over two objects with dynamic key I want to do simple thing - I want to iterate over list of two objects and use displayColumns as dynamic keys to get values from selectList object:  &lt;aura:attribute name="displayColumns" type="String[]"/&gt; &lt;aura:attribute name="selectList" type="Object[]"/&gt;   &lt;table&gt;     &lt;aura:iteration items="{!v.selectList}" var="elem"&gt;     &lt;tr&gt;         &lt;aura:iteration items="{!v.displayColumns}" var="col"&gt;             &lt;td&gt;{!elem[col]}&lt;/td&gt;         &lt;/aura:iteration&gt;     &lt;/tr&gt;     &lt;/aura:iteration&gt; &lt;/table&gt;   In pure JS I would do: elem[col.value], but in lightning compiler returns:      expecting a positive integer, found 'col' at column 6 of expression:   elem[col.value]: Source   Is there any workaround without creating proper object structure in controller? How to automate generation of image files? Evaluate the infinite product $$\lim_{ n\rightarrow\infty }\prod_{k=2}^{n}\left ( 1-\frac{1}{k^2} \right ).$$  I can't see anything in this limit , so help me please. What's the max height of blocks for a redstone contraption to still work even I'm in the surface below?  Like if I build a pillar to the max height of blocks and build a redstone contraption there, is it still going to work even I'm on the surface below? Turn off paragraph indention for a single line New Graphics Card Preventing Boot Up How to turn off Wireless power management permanently On the grade of an ideal I need to prove the following statment (actually a special case of it).     Let $R$ be a Noetherian ring, $M$ a finite $R$-module and $I$ an ideal of $R$. Then   $\operatorname{grade}(I,M)\geq 2$ if and only if the homomorphism $M\rightarrow$Hom$_R(I,M)$ given by $m\mapsto(i\mapsto im)$ is an isomorphism.   This is Exercise 1.2.24 in Bruns and Herzog, Cohen-Macaulay Rings. How to determine function name from inside a function Tangent lines to ellipse from external point How to re-link missing blender files I have multiple characters linked to a blender file, but i moved the original character files and now blender is sating they're missing.  Is it possible to get blender to find the missing blender files like it finds missing image files so that i can preserve the previously made animation?  On a side note is there a way to also view a list of all the missing files? How to prove that a compact set in a Hausdorff topological space is closed? What are good methodologies for creating sprocs that reduce the pain of debugging? And what tools are out there for debugging stored procedures?  Perhaps most importantly, what are indications to look out for that errors are happening in a sproc and not in the code? I hope I'm not all over the board too terribly bad here. Votes for answers to any of the above. Thanks.  For what it's worth, I work in a .NET environment, SQL servers. Monitoring contents of files/directories? In the C and C++ programming languages, what is the difference between using angle brackets and using quotes in an include statement, as follows?   #include &lt;filename&gt;  #include "filename" Can PS4 Minecraft join with PC Minecraft? How to compute the series: $\sum_{n=0}^{\infty} (-1)^{n-1}\binom{1/2}{n}$ I'm sure its a simple question and I suppose it was asked many times, but I just can't figure it out from other answers, sorry.  I use recent versions of PostgreSQL and MySQL. I have 2 tables:  CREATE TABLE authors (     id INT,     name VARCHAR )  CREATE TABLE posts (     id INT,     author_id INT,     text VARCHAR,     date DATE )   I need to select one most recent post for each author. Thanks!  UPDATE  Thanks, both links provide answers to my question with some exception. All the following queries give the same result (which one is the most efficient btw?) The issue is when there is more than one post from the same author with the same date. Then the returned result set contains all such posts. How should I modify these queries to return exactly one post per author?  SELECT p1.* FROM posts p1 LEFT JOIN posts p2 ON p1.author_id = p2.author_id AND p1.date &lt; p2.date WHERE p2.author_id IS NULL ORDER BY p1.author_id;  SELECT p1.*  FROM posts p1 INNER JOIN (   SELECT author_id, MAX(date) AS max_date   FROM posts   GROUP BY author_id) p2   ON p1.author_id = p2.author_id AND p1.date = p2.max_date ORDER BY p1.author_id;  SELECT * FROM posts p1 WHERE date = (SELECT MAX(p2.date)               FROM posts p2               WHERE p1.author_id = p2.author_id) ORDER BY author_id;  SELECT * FROM (     SELECT author_id, MAX(date) date     FROM posts GROUP BY author_id ) p1 INNER JOIN posts p2 USING (author_id, date) ORDER BY author_id; Can I nohup/screen an already-started process? I'm doing some test-runs of long-running data migration scripts, over SSH. Let's say I start running a script around 4 PM; now, 6 PM rolls around, and I'm cursing myself for not doing this all in screen.  Is there any way to "retroactively" nohup a process, or do I need to leave my computer online all night? If it's not possible to attach screen to/nohup a process I've already started, then why? Something to do with how parent/child proceses interact? (I won't accept a "no" answer that doesn't at least address the question of 'why' -- sorry ;) ) Sponsor Gallery, Page, or Something Like That? nhj asked the other day,  In , I wrote:     We were thinking of putting together a "sponsor gallery" of sorts that listed out all of the sponsors with a brief description. Kinda in the vein of what we have on the every-now-and-then  at TDWTF.   So, consider this the discussion for that topic.   What would you like to see in a sponsor gallery? Should it be one big, long list? How does the order get determined? Should we organize the sponsors based on tags (and if so, what about sponsors who target like java and .net)? What about former sponsors... do they get removed from the list, or go on like the "past sponsors" section/page?  Keep in mind that this is not something we intend to charge extra for... this is more a service to the you, the members, than anything else. I've gotten postive feedback from the TDWTF "gallery", as a lot of readers come through RSS, have adblock running, etc.