I was looking at this image and reading through the Wikipedia page for viruses and it says that to satisfy the definition of "being alive" the organism must have a cellular structure, but it seems to me that if an organism has all these other factors without a cellular structure, it is still seemingly alive, no?  So why exactly does an organism need a cellular structure to be alive? What is the rationale for that criteria?
The recent  about a new supermassive virus being discovered got me thinking about how we define viruses as non-living organisms whilst they are bigger than bacteria, and much more complex than we first gave them credit for.   What biological differences between viruses and cellular organisms have made viruses be deemed non-living?
How to add repository from shell in Debian? threeparttablex table notes for tabu tabulars with less than \textwidth Google AdSense Policy Non Compliant "Site Behaviour: Navigation" Past tense and the phrase "who knows what" SQL - an error occurred during the pre-login handshake Explain why $E(X) = \int_0^\infty (1-F_X (t)) \, dt$ for every nonnegative random variable $X$ How can a single slit diffraction produce an interference pattern? How can a light passed though a single slit produce a similar interference pattern to the double-slit experiment? How does the diffracted wave produce the points of cancellation and reinforcement, if there is only one wave? Why can't I press the Install button when installing applications from unknown sources? I'm trying to sideload an application, as seen in the picture below.    I have allowed the installation of applications from unknown applied actions in settings, but I can't seem to press the install button. The cancel button works correctly and installing applications via adb install works correctly. What's the problem?  EDIT: For those who have this problem, using ChainFire's  will correct it because the app uses hardware compositing, and Android doesn't notice a "layer" on top of the current screen. The Find Familiar spell states, in part:  As an action, you can temporarily dismiss your familiar. It disappears into a pocket dimension where it awaits your summons.  The question arising from this is:  Is this pocket dimension different for every familiar in the world? Thus being a personal pocket dimension? If this is true, then it should be able to store items given by its master for safe keeping away from anyone else, as long as these are items that a familiar could carry with it. Can the familiar bring small items with it into the pocket dimension for safe keeping? Why does DMM show AC and DC current when source is a battery? (How to calculate power in this case?) The circuit is an altered Joule Thief of my design that is driven by an AA or AAA battery. I’m observing the current at the battery anode with my DMM in series. (Extech EX330) This circuit is extremely efficient (In relation to other Joule Thief I've build.) and does some weird stuff - like, it needs a pushbutton sometimes.    Measurements: It is drawing 9.21 mA DC and 6.48 mA AC in series with the battery. It shows 1.364 VDC and 0.010 VAC in parallel with the battery. Output on the LED is 2.572 VDC and 0.011 VAC with no measurable frequency. (with my DMM at least) All measurements are taken with the same configuration and voltage.    But how is it drawing AC and DC and how do I calculate power consumption? --> Could it be because the emitter pin of the NPN is directly connected to ground? --> Or is the circuit just "switching on and off"?     Download schematic:  (I tried to simulate the circuit in LTspice. Thanks for making me aware of this amazing program, Sredni Vashtar!)     What the pushbutton is used for: The pushbutton is used to "kickstart" the oscillation when it wont start by itself. For example: I have to manually "oscillate" using this button to start the circuit if the capacitor is too big and battery voltage is low. Pushing the button releases the energy in the transformer into the capacitor. If it reaches LED forward voltage the circuit keeps oscillating on it's own. It does work without manual intervention when then capacitor in parallel with the LED is not too big, like &lt;5000 µF, and it's a fresh battery.    . Thank you for your answers! I'm learning so much! :D What does this cryptic Bash command mean? I was reading Ubuntu Forum's warning about malicious commands and found this interesting gem:  :(){ :|:&amp; };: WARNING: The above code will crash your machine unless you have strict proc limits in place (which you probably don't) prompting a hard restart. Consider this code similar to running sudo rm -rf /.  But what does that mean? Even with my programming experience I've never seen a command that cryptic that's not assembly language. Let $\Gamma$ be a set of formulas and $\phi$ be a formula. Show that $\Gamma \cup \{\neg \phi\}$ is satisfiable if and only if $\Gamma\not \models \phi$.   This seemed pretty obvious but I wanted to see if my proof made sense:  Proof: $(\Rightarrow)$  To derive for a contradiction, suppose that: $\Gamma \models \phi$. That means for all truth assignments $v$, for $\gamma \in \Gamma$, if $v(\gamma) = T$, then $v(\phi) = T$.  But this contradicts our assumption that $\Gamma \cup \{\neg \phi \}$ is satisfiable by the fact that $v(\phi) = T$ cannot happen so: $\Gamma \not \models \phi$ .  $(\Leftarrow)$   So by the definition of $\Gamma \not \models \phi$, we have that there is some truth assignment $v$ which satisfies $\Gamma$ but does not satisfy $\phi$. So  that means $v(\phi) = F$ since $v(\phi) \not = T$ which implies that $v(\neg \phi) = T$ which means $v$ satisfies $\Gamma \cup \{\neg \phi\}$.    I feel like I'm missing something in the forward direction, but at the same time... It looks pretty trivial as well. Am I missing anything crucial?  Thank you! CMake & CTest : make test doesn't build tests What is Java's answer to WPF? Is there a privacy setting on Facebook that will stop the posting that is made on your friend's wall when you make a new friend?  I do not want this to appear on my friend's wall when I make a new friend End Process vs End Process Tree What is the primary difference between the two? I always see this in the right click menu in windows. What happens if you end a process that is relied upon by another process? Is there a way to "kill" a process tree in linux or is the technology different? What's the reason I can't create generic array types in Java? Hi this must be a basic question but I haven't seen an answer with cerbot considerations (if there are any considerations). How do I get https www to redirect to non-www instead of timing out?  The https www version of my site times out instead of redirecting to non-www, whereas all other versions (http and https non-www) work fine.  Preferably I would like to future proof so that I can renew the certs through certbot and not need to manually change the nginx config afterwards.  The nginx server config is shown below:  server {     listen 80 default_server;     listen [::]:80 default_server ipv6only=on;     server_name www.mydomain.com mydomain.com;      listen 443 ssl; # managed by Certbot     ssl_certificate &lt;path_to_cert&gt; # managed by Certbot     ssl_certificate_key &lt;path_to_key&gt;; # managed by Certbot     include /etc/letsencrypt/options-ssl-nginx.conf; # managed by Certbot     ssl_dhparam &lt;path_to_this&gt;      if ($scheme != "https") {         return 301 https://$host$request_uri;     } # managed by Certbot } What Wording Did Witches and Wizards in Other Cultures Use for Spells? Should flagging a question for closure prevent close-voting? Back in April, I flagged a post as "not a real question".  The post was subsequently closed and reopened, then closed again and finally just reopened a 2nd time a short time ago.  I still firmly believe the post is not acceptable for SO, so I went to use my recently acquired close vote privilege and was greeted with the following messsage:    I specifically clicked close and not flag (and figuring I just clicked in error, I tried again and got the same message).  I do understand that, in the new closing system, flagging for closure is treated very much like a close vote (since it throws it to the close vote queue) except no vote is actually recorded.  My issue is why should by flag be counted as a close vote when I never actually voted to close.