Descartes's cogito falls short
Could 'cogito ergo sum' possibly be false?
A screen of mine burnt out, and was replaced with a screen of lower resolution. It works in safe mode as that is in 800x600 resolution, but when I try to boot to normal mode, it fails. Is there a way to change the resolution for normal mode in safe mode? I'm not sure if there's a better place to ask this or not.   Why, at least here in America, is the standard electrical system set up for alternating current (AC) rather than direct current (DC)? I'm just completing a long-distance move and realizing how many DC adapters I have and how many of my devices require DC power:   All of my guitar pedals. My alarm clock. My external hard disks. My USB car HDD dock.   ... and the list goes on. If we're almost constantly having to use DC adapters to convert AC into DC, why isn't the standard DC, other than because people resist change? If I want to shoot darker shots, is it better to increase the lighting and then darken in post to retain clarity? I'm just getting started - in my last shoot, I was using a 6D with a 50mm/1.4.  In low light, the pictures looked fantastic on the viewfinder but on the computer screen, appeared extremely grainy.  For future shoots, if I want to achieve something like this:     Should I shoot with way more light / lower ISO to retain clarity, and then just darken in post?  What kind of setup would be needed to achieve the above?    With my setup -   Camera Canon EOS 6D  Lens EF50mm f/1.4 USM  Focal Length 50mm  Shutter Speed 1/40 s  Aperture f/1.8  ISO/Film 6400  I was getting very grainy results that I had to soften in post (in case you want to see my attempts):      Any tips would be much appreciated. The files are "ready to download" or "ready to be downloaded"? Both ways seem to be used quite interchangeably even though the first one doesn't seem grammatical to me (English is, however, my second language so I could be miles off here). What do you think? How big an RSA key is considered secure today? I think 1024 bit RSA keys were considered secure ~5 years ago, but I assume that's not true anymore. Can 2048 or 4096 keys still be relied upon, or have we gained too much computing power in the meanwhile?  Edit: Lets assume an appropriate padding strategy. Also, I'm asking both about security of signatures and security of data encryption. I wanted to tweet something on the lines of "Stack&nbsp;Overflow is awesome". When I do this kind of stuff, I usually use a username (for example: ) or a hashtag ()  I found , but it seems it is from someone unrelated with Stack&nbsp;Overflow.  Is there a Twitter account I can reference, or should I use a hash-tag? Should I just point to the site?  Thanks!  (Notice: I've seen lots of questions regarding Twitter and Stack&nbsp;Overflow, but those are mostly about integration/login with Twitter for the users accounts; I'm just asking for a single account for Stack&nbsp;Overflow; probably for announcements and PR, which is different) When does Ubuntu 16.04 use /etc/apache2/ssl/apache.crt? I have some Ubuntu 16.04 server running and set up one vhost in apache2 which uses (or should use) ssl.  &lt;IfModule mod_ssl.c&gt;         &lt;VirtualHost *:443&gt;          ServerAdmin myemail@mailhoster.xx         ServerName my.domain.name.de         DocumentRoot /var/www/mysslsite          &lt;Directory /var/www/mysslsite&gt;                 Options FollowSymLinks MultiViews                 AllowOverride All                 Order allow,deny                 allow from all         &lt;/Directory&gt;          ErrorLog ${APACHE_LOG_DIR}/mysite.ssl.error.log         CustomLog ${APACHE_LOG_DIR}/mysite.ssl.access.log combined          &lt;/VirtualHost&gt; &lt;/IfModule&gt;   I did NOT enable the standard sites-available/default-ssl.conf.  I am able now to browse to  and it is asking in firefox to add some exception which is totally normal if i did not buy any certificate.  But I was wondering where it is set up that it should use the certificates in /etc/apache2/ssl/ directory. I can not find any config where it is told to use that. I all the time was thinking that it will use something from /etc/ssl folder.   Or did I maybe not activate SSL correctly? Prepositions used with "inquire" I'm having a really hard time trying to understand what the differences between a desktop environment and a window manager are?  EDIT: From this :  There are basically three layers that can be included in the Linux desktop: X Windows – This is the foundation that allows for graphic elements to be drawn on the display.  builds the primitive framework that allows moving of windows, interactions with keyboard and mouse, and draws windows. This is required for any graphical desktop. Window Manager – The Window Manager is the piece of the puzzle that controls the placement and appearance of windows. Window Managers include: , , , , , etc. Requires X Windows but not a desktop environment. Desktop Environment – This is where it begins to get a little fuzzy for some. A Desktop Environment includes a Window Manager but builds upon it. The Desktop Environment typically is a far more fully integrated system than a Window Manager. Requires both X Windows and a Window Manager.  Examples of desktop environments are , , ,  among others) I have recently been reading about Quantum Electrodynamics which I found very interesting, but even more confusing.  I understand photons mediate the electromagnetic force and interactions between charges can be described by virtual photon exchange. And that in Quantum Mechanics particles paths can be evaluated by sum over all paths...  An electron travelling from one point to another will take all paths, emitting and reabsorbing virtual photons. Does the electrons take all paths including those that involve faster than light velocities?  Is this question null, Does it mean anything to ask about properties of virtual particles?  Do I have the wrong idea about what virtual particles are? Word for in-house jargon I am wondering if there is away (possibly a better way) to order by the order of the values in an IN() clause.  The problem is that I have 2 queries, one that gets all of the IDs and the second that retrieves all the information. The first creates the order of the IDs which I want the second to order by. The IDs are put in an IN() clause in the correct order.  So it'd be something like (extremely simplified):  SELECT id FROM table1 WHERE ... ORDER BY display_order, name  SELECT name, description, ... WHERE id IN ([id's from first])   The issue is that the second query does not return the results in the same order that the IDs are put into the IN() clause.  One solution I have found is to put all of the IDs into a temp table with an auto incrementing field which is then joined into the second query.  Is there a better option?  Note: As the first query is run "by the user" and the second is run in a background process, there is no way to combine the 2 into 1 query using sub queries.  I am using MySQL, but I'm thinking it might be useful to have it noted what options there are for other DBs as well. Notification that ‘someone might be watching what you browse’ If $f(x)$ is continuous on $[a,b]$ and $M=\max \; |f(x)|$, is $M=\lim \limits_{n\to\infty} \left(\int_a^b|f(x)|^n\,\mathrm dx\right)^{1/n}$? Let $f(x)$ be a continuous real-valued function on $[a,b]$ and $M=\max\{|f(x)| \; :\; x \in [a,b]\}$. Is it true that: $$ M= \lim_{n\to\infty}\left(\int_a^b|f(x)|^n\,\mathrm dx\right)^{1/n} ? $$  Thanks! How to change camera movement speed on Path during animation Im making a animation in blender that requires the camera to change speeds while moving along a path. I'm using the Curve/Path for the path. I need the camera to move at a certain speed going between 2 places, and then slow down while moving around something its focusing on. How would I implement a realistic stock market? Magnetic field lines When I searched the net about magnetic field lines,  told something about contour lines and that magnetic materials placed along a magnetic field has some specific loci, which i did not understand. Can someone explain it to me in details.  Also how do we know that tangent to a magnetic field line gives the direction of magnetic field? I am very confused. Prove that $\liminf x_n = -\limsup (-x_n)$ How can we prove that $\liminf x_n = -\limsup (-x_n)$?  The definitions we are using are $\limsup x_n = \lim\limits_{n\to\infty} \sup\{x_k; k\ge n\}$ $\liminf x_n = \lim\limits_{n\to\infty} \inf\{x_k; k\ge n\}$ How can I get grub2 to boot a different option only on the next boot? Where do the regions of Westeros appear to align as of the season 6 finale? Based on , my understanding is that there are 9 regions of Westeros subject to the rule of the Iron Throne, from Dorne joining up to Cersei killing Robert.  With whom does [insert region] align in what appears to be Daenerys vs Cersei?   Kingdom of the North -- Daenerys probably but currently busy with White Walkers Kingdom of the Mountain and the Vale -- Daenerys probably but currently busy with White Walkers (supposedly; depends on what Littlefinger has in mind) Kingdom of the Isles and Rivers (Iron Islands) -- Daenerys Kingdom of the Isles and Rivers (Riverlands) -- Cersei because the Freys are with the Lannisters? Kingdom of the Rock -- Cersei because she is a Lannister Kingdom of the Stormlands -- Cersei? Kingdom of the Reach -- Daenerys after invitation of Varys and Ellaria Principality of Dorne -- Daenerys after invitation of Varys presumably Crownlands -- Cersei since Cersei is currently occupying the Iron Throne   Am I understanding this right? Anything wrong?