I encounter a contradiction.   Many resources state that a digital sensor are unsensitive to UV light. Even wikipedia, "However, newer photographic film and digital cameras are highly insensitive to UV wavelengths." .  Digital Photography Review goes even to the point that a digital photographer won't even need it on a beach (an UV-light rich area). "digital sensors are not and hence do not need UV filters in even bright sunlight".   While other resources state that digital sensor are sensitive to UV light.    Can someone clarify this contradiction?  My prognosis is that a digital sensor is sensitive to UV light, but sensor manufactures include an UV blocking system on the sensor. But I don't know if that's true. I do know that IR light is blocked through a IR-absorption glass on the sensor itself.   Is my prognosis correct?
Is there any way, shape, or form that ultraviolet light is recorded by a digital sensor?  Ideally, this question is related strictly to the sensor, without even a glass lens in between which could cut or block UV light.  But of course I don't take pictures with a bare sensor, I also have a lens, so I'd also like to know how much UV gets to the sensor to begin with.
Why is my StackOverflow with an indent and doesn't have reputation I was going to make a filter for the &quot;&quot; by excluding some sites from it.  I noticed  which talks about &quot;negative filtering&quot; but does not explain how one can do it or if it is possible.  There does not seem to be a way to do this, though.  On the filter page, my only options are:  So how can I do &quot;All sites except [list]&quot;? It would also be nice if this could include similar functionality with the meta checkbox.  Something like &quot;All main &amp; meta sites except...&quot; I'm more of a math guy than a physics guy so bear with me....  In fractal geometry, fractals are considered to have fractional dimension. For instance an object such as the Koch curve has a fractal dimension of around $1.2$. You can also define a concept called fractal extent (which is the experimental version of hausdorff measure). This extent is a measure of how large a fractal is. It's even been used to more accurately model the distribution of coastline bird nesting.   Even though fractals work as an interpretation of geometrical units, I don't think they would describe things such as $kg^{1/2}$ very well. In addition, I've heard about white Gaussian noise that has square root time units.   What is the physical meaning of fractional units such as the above? (Since it obviously has little geometric meaning) Scanner is skipping nextLine() after using next() or nextFoo()? Been trying to find graphic novel for decades - at least I think it's a graphic novel When I was a kid I had a book that I loved, as I think about it I'm pretty sure it would be characterized as a graphic novel although I was unfamiliar with that term at the time. It was a large hardcover comic book but a full-length story, probably a few hundred pages long.  This would have been about 25-30 years ago.  I recall a little about the plot: It starts with a spaceship crashing somewhere, I remember one of the first panels had the phrase that the ship "yawed wildly". I always remembered that because I had to look up the word "yawed".   The rest of the story is told in flashback form, with the rise of an empire, and I'm pretty sure there's a guy who's a slave or otherwise in the lower strata of society who rises to be the ruler of the world or something like that.    I thought that the title had the word "titan" or "empire" in it (Empire of the Titans, or Rise of the Titans, or something similar), but Google searches have been unfruitful. Trying to install Ubuntu on Dell XPS 15 (9570) I have been trying to install Ubuntu on my new laptop:     Dell XPS 15 (9570)   Windows 10 Home 64bit English   8th Generation Intel(R) Core(TM) i7-8750H Processor (9M Cache, up to 4.1 GHz, 6 cores)   16GB, 2x8GB, DDR4, 2666MHz   256GB M.2 2280 PCIe Solid State Drive   NVIDIA(R) GeForce(R) GTX 1050Ti with 4GB GDDR5     I began by trying to install Ubuntu 18.04 LTS using an 8GB USB drive. The first issue I ran into was getting frozen on the bootup screen on the fourth dot. After a couple tries, I plugged in my monitor (through HDMI) and it stopped getting stuck all of a sudden.    Next, I tried to go through the installation and when I clicked on restart now, my computer froze and I had to shut it down manually and start it back up again. At this point I got to the login screen and logged in but after entering my password it got stuck on a purple screen with my mouse pointer (which was frozen). I was able to get into a shell at this point (with ctrl+alt+f4) and attempted to run sudo apt-get install nvidia-390 but this froze when it reached building initial module for 4.15.0-22-generic and upon reboot I had to run sudo dpkg --remove -a.    I was unable to work around this so I attempted to install Ubuntu 16.04 which I could only do by adding acpi=off to the boot configuration (which by the way, I had a lot of trouble getting to since GRUB usually flashed in and then immediately disappeared and only occasionally would it stick around long enough for me to use). But when I try to boot up now, I never reach the screen with the five dots and instead immediately get stuck on a purple screen (with no mouse pointer).  I reinstalled Ubuntu 18.04 and am back to being stuck on the log-in screen.  What should I do? pgfplots -> contour gnuplot with lualatex instead of pdflatex How to migrate a WordPress installation from one site to another, including all images? Is there a general relation between $a/b$ and $(a+c)/(b+c)$ where $a,b&gt; 0$ and $c\geq 0$ ?   Is there a general proof for that relation ? Environment for two columns with lstlistings In order to reduce copy-pasting, I want to create an environment that will produce a two-column table with headers and two listings in different languages, like below:  \begin{tabular}{l l} Python &amp; Haskell \\ \hline \\ \lstset{language=Python} \begin{lstlisting} A \end{lstlisting} &amp; \lstset{language=Haskell} \begin{lstlisting} B \end{lstlisting} \end{tabular}   I want to use it like below, hiding everything but code:  \begin{comparison} A \vs B \end{comparison}   So far I tried making two new environments (instead of a \vs command inside) with \lstnewenvironment, where first environment had \tabularx command and second \endtabularx. I also tried creating normal \newenvironment for this tabular, &amp; for \vs command and manually inserting \begin{lstlistings} and \end{lstlistings} with code, but it stopped compiling when I put lstlistings inside.  How can I create such an environment?  EDIT: The most compact version I've came up with until now is  \newenvironment{comparison} {\begin{parcolumns}[nofirstindent,distance=0pt,colwidths={1=0.35\textwidth}]{2}} {\end{parcolumns}}  \lstnewenvironment{python} {Python \lstset{language=Python,frame=t}} {}  \lstnewenvironment{haskell} {Haskell \lstset{language=Haskell,frame=t}} {}   which is used like that:  \begin{comparison} \colchunk{ \begin{python} A \end{python} } \colchunk{ \begin{haskell} B \end{haskell} } \end{comparison}   I'm still unable to hide \colchunk{} within python or haskell environments. self referential struct definition? View list of files in ZIP archive on Linux How do I change "Show Applications" button on GNOME 3 dash? I'm using Ubuntu with GNOME desktop.   I was wondering how to change the "Show Applications" button icon on the dash? Minimum of the Gamma Function $\Gamma (x)$ for $x>0$. How to find $x_{\min}$? Multi document printing from document library? Is there any one have solution for print multiple documents from Document library? User has option to select multiple documents or single document or inside folder.  I found commercial product "Unbounded Printing Services for SharePoint". But is so expensive. Please share me if you have any thoughts. How do I move Steam games to a new computer without re-downloading them? I have just bought a new computer and I have everything migrated over except for my Steam games.  I looked in Program Files/Steam/ and I found a folder full of the games I have downloaded, but I do not know if it is safe to just copy these folders from one computer to another (seeing as a lot of other applications will not work if you do this), or is there another recommended way?  I don't really feel like re-downloading all my games. I don't have the time nor bandwidth to download 20GB over a 1.5mbps connection.  Is it possible to contact Valve and get a disk with the games on it? Isomorphism equivalence implies fundamental group is abelian I'm trying to solve hard combinatorics that involve complicated factorials with large values.  In a simple case such as $8Pr = 336$, find the value of $r$, it is easy to say it equals to this: $$\frac{8!}{(8-r)!} = 336.$$  Then $(8-r)! = 336$ and by inspection, clearly $8-r = 5$ and $r = 3$.  Now this is all and good and I know an inverse function to a factorial doesn't exist as there is for functions like sin, cos and tan etc. but how would you possibly solve an equation that involves very large values compared to the above problem without the tedious guess and checking for right values.  Edit: For e.g. if you wanted to calculate a problem like this (it's simple I know but a good starting out problem) Let's say 10 colored marbles are placed in a row, what is the minimum number of colors needed to guarantee at least $10000$ different patterns? WITHOUT GUESS AND CHECKING  Any method or explanation is appreciated! In Lubuntu, there's no 'Add New Program...' button in Desktop Session Settings. Is there an easy way to add new autostart programs in Lubuntu? Let $f : U \to V$ and $g : V \to W$ be linear transformations on the vector spaces $U$, $V$, and $W$. Supposedly,  $$ \dim(\ker(g \circ f)) = \dim(\ker(f)) + \dim(\ker(g) \cap \operatorname{im}(f)). $$  How might I go about proving that?    (Attempt:) The $\dim(\ker(g)\cap\operatorname{im}(f))$ term suggests to me that I should define a vector space $V' = \ker(g) + \operatorname{im}(f)$ to invoke the theorem that  $$ \dim(V') = \dim(\ker(g)) + \dim(\operatorname{im}(f)) - \dim(\ker(g) \cap \operatorname{im}(f)), $$  but I don't really see where to go from there.