How did Planck solve the UV catastrophe? From online sources, I've seen that this had to do with quantization of energy. Somehow I cannot wrap my head around this.   Can any of you please explain? Thank you for your time :)
Max Planck, arguably the leading theoretical Physicist of his day, apparently used of experimental data to formulate his equation for , which was a major step in the birth of quantum mechanics. For this seminal event of the 20th century, I would expect a detailed explanation of how Planck arrived at his conclusion that energy MUST be quantized. I've even read his Nobel lecture but was non the wiser.  Can some kind person please explain it, or give me even just a hint?
has been, have been , had been Please anyone tell me when we have to use "has been, have been , had been" and something  started in past and still continuing is it possible to use has been ? Suspending with root on USB I have a laptop running Ubuntu 14.04 from a root file system on USB storage. This is not working well, because after wake up from suspend, ext4 will frequently try to write to the root file system before USB is ready.  Here is what I see in the kernel log when this happens, notice how I get a bunch of I/O errors on sda1, and then one second later the USB storage drive is finally detected by the kernel.  [ 2826.517419] wlan0: associated [ 2826.517452] IPv6: ADDRCONF(NETDEV_CHANGE): wlan0: link becomes ready [ 2827.575371] EXT4-fs warning (device sda1): ext4_end_bio:317: I/O error -5 writing to inode 1733735 (offset 0 size 0 starting block 12629950) [ 2827.575380] Buffer I/O error on device sda1, logical block 12629694 [ 2827.575400] EXT4-fs warning (device sda1): ext4_end_bio:317: I/O error -5 writing to inode 3148603 (offset 0 size 8192 starting block 12844470) [ 2827.575404] Buffer I/O error on device sda1, logical block 12844212 [ 2827.575411] Buffer I/O error on device sda1, logical block 12844213 [ 2827.575448] EXT4-fs warning (device sda1): ext4_end_bio:317: I/O error -5 writing to inode 3015015 (offset 0 size 90112 starting block 6588832) [ 2827.575453] Buffer I/O error on device sda1, logical block 6588576 [ 2827.575461] Buffer I/O error on device sda1, logical block 6588577 [ 2827.575465] Buffer I/O error on device sda1, logical block 6588578 [ 2827.575469] Buffer I/O error on device sda1, logical block 6588579 [ 2827.575473] Buffer I/O error on device sda1, logical block 6588580 [ 2827.575477] Buffer I/O error on device sda1, logical block 6588581 [ 2827.575481] Buffer I/O error on device sda1, logical block 6588582 [ 2828.857284] sd 0:0:0:0: [sda] No Caching mode page found [ 2828.857293] sd 0:0:0:0: [sda] Assuming drive cache: write through   At first there is no visible indication outside of the kernel log, that the problem has triggered, but if I let Ubuntu stay running beyond this point, then the file system will get errors and eventually switch to read only mode. At that point I have to reboot into recovery mode and run fsck.ext4 manually from a root shell in order to repair the file system.  Is there some setting I can change such that access to the root device after waking from suspend can be delayed until the USB drive is ready? Experience using dropdowns in-line of sentence "mad lib" style Do you have experience implementing text inputs or drop-downs in-line with other text or forms? Is this approach any better than just creating a separate field/label?  In the example below the user has the option to indicate when to be reminded again (in one, two, or three days). When they are reminded of an assignment, they simply get an email or text message. How to open Nautilus at current command line directory? I was wondering if anybody knew a command that would allow me to open a Nautilus (if that's the right name for the Ubuntu graphic/window explorer) window from the command line at the current directory that the user is at.  So, if I open a command line, and type:  cd /home/myUser/some/long/path/to/a/directory   Then, I'd like to be able to issue some command:  nautilus open-sesame   And have a graphic window opened to /home/myUser/some/long/path/to/a/directory. Is this even possible? Short story with spaceship and humanity not realising they should be on it The plot is about:   A spaceship travelling through the universe Earth is a rogue planet whose inhabitants have been cut off and don't realise that their true purpose is to be part of the spaceship   The reason earth was in turmoil (wars etc.) was that they didn't realise that their true role was to fit into the ship  The ship contained 3 or 4 beings that made the thing work Planets throughout the universe are populated with the various beings which are components of the space craft   I seem to remember like an eye shaped being Each of them fulfil their role Humans are part of that as well.  There are loads of planets with humans on but earth has gotten overlooked so it never realised that's what they were designed for The story concludes with the ships picking up someone from Earth   and with the "human" realising that this is what they should really be doing  Humans have a different name that explains their role in the ship.   I probably read it around 30 years ago in English in a sci-fi collection book. WebView loading Url Is it bad to use a pacifier? I've been using it when she gets fussy and she seems to love it. Is this a bad habit to get into? I've heard there are potential dental/breastfeeding/dependency issues. Is there any truth to this? I have critical low storage level and can't understand what takes much of it and how that's possible that the installed applications can use 7 GB? I only use a few social media clients without any games or soft like Photoshop. Also on the second screenshot it indicates that the apps are using just 1.13 GB and so I can't understand the situation. Also what is the "Other"? PHP regular expressions: No ending delimiter '^' found in Why do we not use the definite article in "Where can I find the room 401?" Last week in college, a student [with a thick South Asian accent] asked me:     "Excuse me, where can I find the room 401?".   I realized that to my native English ears, the word "the" sounded non-native. This had me realize that we sometimes use no article.  I am learning French; in French, we seem to always use some kind of article before nouns. It surprised me, at that moment, to realize that English doesn't always do the same! (That, and using the definite article in "the room 401" seems to make sense if I think about when definite articles are used).  Is there a grammatical name or concept for this "no article" aspect of our language? Are there any websites that can explain this to me? Add anchors to the how-to-ask and how-to-answer pages Google Chrome (Windows) not displaying text/encoding correctly on certain websites I experience a problem similar to    Here's a screenshot on the website     I've tried:   Removing fonts I have installed Setting the encoding to Western, UTF-8, Greek, Automatic Changing the fonts used in Google Chrome Removing Google Chrome, including all application data/user profiles Running CCleaner Reinstalling Google Chrome, twice Installing Chromium (fonts display fine in Chromium) Turning off Windows ClearType Changing Windows/Chrome languages from English (Australia) to US, UK Restarting Windows several times after making changes   All of which did not work. I do not connect over VPN/proxy.   Can anyone give me any tips?  Windows 7 x64 Ultimate I've been using the biblatex package for a while, and since updating my TeX installation (post-el capitan upgrade) I have been experiencing the following.   If the following is typed:  Such and such has been said \citep[111]{citekey}.   The following text is displayed:  Such and such has been said (Author, 2016, p. 111).   And if the following is typed:  \citet[111]{citekey} has said such and such.   The following text is displayed:  Author, (2016, p. 111) has said such and such.   The citep command is working as I want it to, but I do not want a comma placed after the author's name when using the citet command. I would like it to display as follows:  Author (2016, p. 111) has said such and such.    If I use the \citeyearpar command, it is fine, but I would rather not have to type the author's name in manually.   Here is the command placed in the preamble:  \usepackage[backend=bibtex, style=authoryear-icomp, url=true, isbn=false, natbib=true, sortcites=true, block=space, pagetracker=false, loccittracker=constrict]{biblatex}   Here is an example of an entry in my bib file (made using BibDesk):  @article{poldrack2006, Author = {Poldrack, Russell}, Journal = {Trends in Cognitive Sciences}, Number = {2}, Pages = {59--63}, Title = {{Can cognitive processes be inferred from neuroimaging data?}}, Volume = {10}, Year = {2006}}   I have also tried changing the entry to the following:  @article{poldrack2006, Author = {Russell Poldrack}, Journal = {Trends in Cognitive Sciences}, Number = {2}, Pages = {59--63}, Title = {{Can cognitive processes be inferred from neuroimaging data?}}, Volume = {10}, Year = {2006}}   The bibliography entry appears as follows, and is fine:  Poldrack, Russell (2006). “Can cognitive processes be inferred from neuroimaging data?” In: Trends in Cognitive Sciences 10.2, pp. 59–63.  Thank you for any help that can be offered. How can I automatically forward Facebook messages to my email or phone? I can create email addresses that forward to other email addresses.  Likewise, can I automatically forward Facebook messages to either my email or phone? How can I draw a graph like the diagram below? I'm trying, but something is wrong with my code in LaTeX: \begin{asy} pair dynkinMark(real x, real y, string s = &quot;&quot;, pen p = defaultpen, pair B = dir(45)) { if (s != &quot;&quot;) { dot(&quot;$&quot;+s+&quot;$&quot;, (x,y), B, p); }     else { dot((x,y), p); }     return (x,y); }  dynkinMark(0,1, &quot;1&quot;, dir(135)); dynkinMark(0,2, &quot;2&quot;, dir(135)); dynkinMark(0,3, &quot;3&quot;, dir(135)); dynkinMark(0,4, &quot;4&quot;, dir(135)); dynkinMark(7,1, &quot;1'&quot;); dynkinMark(7,2, &quot;2'&quot;); dynkinMark(7,3, &quot;3'&quot;); dynkinMark(7,4, &quot;4'&quot;); path p1 = (0,1)..(2,2.0)..(5,3.5)..(7,4); path p2 = (0,2)..(2,1.2)..(5,2.5)..(7,3); path p3 = (0,3)..(2,2.8)..(5,1.5)..(7,1); path p4 = (0,4)..(2,3.8)..(5,3.5)..(7,2); draw(p1, blue); draw(p2, heavycyan); draw(p3, mediumcyan); draw(p4, lightblue); dot(&quot;$12$&quot;, IP(p1, p2), dir(90), heavygreen); dot(&quot;$13$&quot;, IP(p1, p3), dir(90), heavygreen); dot(&quot;$23$&quot;, IP(p2, p3), dir(90), heavygreen); dot(&quot;$14$&quot;, IP(p1, p4), dir(90), heavygreen); dot(&quot;$24$&quot;, IP(p2, p4), dir(90), heavygreen); real y = 0.8; label(&quot;$s_1$&quot;, (IP(p1,p2).x, y), heavygreen); label(&quot;$s_2$&quot;, (IP(p1,p3).x, y), heavygreen); label(&quot;$s_1$&quot;, (IP(p2,p3).x, y), heavygreen); label(&quot;$s_3$&quot;, (IP(p1,p4).x, y), heavygreen); label(&quot;$s_2$&quot;, (IP(p2,p4).x, y), heavygreen); \end{asy} How to find out if an item is present in a std::vector? All I want to do is to check whether an element exists in the vector or not, so I can deal with each case.  if ( item_present )    do_this(); else    do_that(); Calculate business days I need a method for adding "business days" in PHP. For example, Friday 12/5 + 3 business days = Wednesday 12/10.  At a minimum I need the code to understand weekends, but ideally it should account for US federal holidays as well. I'm sure I could come up with a solution by brute force if necessary, but I'm hoping there's a more elegant approach out there. Anyone?  Thanks. Take a look at this example schematic:  The chip in question is the  and as you can see power is provided on both sides (with a 100nF cap to smooth noise I guess). Is this strictly required or could you put power into one side and just ignore the other? I know that I have just put power in one side and everything still seems to work fine but I feel uneasy with doing that. I feel that they would not waste pins that could be doing something useful by having an extra pair of power in/out pins. For what purpose does this PIC MCU (and others like it) have multiple power pins? Why Does the Transaction Log Keep Growing or Run Out of Space? This one seems to be a common question in most forums and all over the web, it is asked here in many formats that typically sound like this:  In SQL Server -  What are some reasons the transaction log grows so large? Why is my log file so big? What are some ways to prevent this problem from occurring? What do I do when I get myself on track with the underlying cause and want to put my transaction log file to a healthy size? How to embed a text file in a .NET assembly? I would like to embed a text file in an assembly so that I can load the text without having to read it from disk, and so that everything I need is contained within the exe. (So that it's more portable)  Is there a way to do this?  I assume something with the resource files?  And if you can, how do you do it and how do you programaticaly load the text into a string?