As per the title. I'm probably thinking too naively in a classical way, but intuitively it seems to me that:   the presence of vacuum energy at fixed density throughout all space and, an expanding universe   would imply that more and more energy is constantly added to the universe.  I am assuming we have not given up on energy conservation quite yet, so where is the catch?
I initially thought that dark energy must in some way violate conservation of mass and energy since the component of the energy density of space that comes from dark energy is constant, and space is expanding. Therefore, as space expands the energy in the universe that comes from dark energy would increase. I presumed the source of this energy was not coming from the conversion of other types of energy to dark energy, so it must violate conservation.  I decided to Google this and came upon this article:    It says that dark energy does NOT violate conservation and quotes Carroll, Press, and Turner (1992):  "…the patch does negative work on its surroundings, because it has negative pressure. Assuming the patch expands adiabatically [i.e. without loss or gain of heat], one may equate this negative work to the increase of mass/energy of the patch. One thereby recovers the correct equation of state for dark energy: P = – ρ c2. So the mathematics is consistent."  Is there a way to explain this in layman's terms? (The blog attempted to do this, but it was very unclear to me.) More specifically, can you explain where my initial train of thought described above fails when I erroneously concluded that dark energy violates conservation?  Thank you.
Dropbox: ext4 isn't ext4 Probability of Various Combinations of Weather There's a 10% chance it will rain today. There's a 15% chance it will snow today.   What percentage chance is it that it will:   Both rain and snow (it can both rain and snow at the same time)? Neither rain nor snow? -   Raining and snowing are independent of each other.  EDIT: (ADDED)   Rain or snow but not both? Aliens like giant grasshoppers invade earth, give black people power over whites WP_query 'orderby=none' Problem I have another database which stores post's IDs and I want do display them using WP_query to use the WP default pagination. I'm using orderby => none to preserve the original order, but the result reorders them by IDs.  $ids = array (60, 23, 78, 46, 105, 130)  $args = array (     'posts_per_page' =&gt; -1,     'post__in' =&gt; $ids,     'orderby' =&gt; 'none' );  $query = new WP_Query ( $args );  while ( have_posts() ) : the_post();     echo '&lt;li&gt;';     the_title();     echo '&lt;/li&gt;'; endwhile;   Could anyone help me?  Thanks, Romulo De Lazzari What are the responsibilities of each Pseudo-Terminal (PTY) component (software, master side, slave side)? I am trying to figure out how a tty works1 (the work-flow and responsibilities of each elements). I have read several interesting articles about it, but there are still some blurry areas.  This is what I understand so far:   The emulated terminal makes different system calls to /dev/ptmx, the master part of the pseudo-terminal. The master part of the pseudo terminal allocates a file in /dev/pts/[0-N], corresponding to the obsolete serial port, and "attaches" a slave pseudo terminal to it. The slave pseudo terminal keeps information such as session Id, foreground job, screen size.   Here are my questions:   Has ptmx any purpose besides allocating the slave part? Does it provide some kind of "intelligence", or the emulated terminal (xterm for instance) has all the intelligence of behaving like a terminal? Why does xterm has to interact with the master part, as it only forwards the stdout and stdin of the slave part? Why can't it directly write and read from the pts file? Is a session ID always attached to one pts file and vice versa? Could I type a ps command and found 2 sessionId for the same /dev/pts/X? What other information does the pts store? Does Xterm update all fields by himself, or does the ptm add some "intelligence" on it?     1. I base my understanding on the , and the  posts, as on several other Finding a research group where I can work remotely? How to make DNS server propagate faster if you are a site owner? It's often the case that I want to change name servers because my site is messed up.  Well, it takes a very long time for the name server to propagate.  Is there something in DNS, or registrar or anything I can do to speed that up.  Flushing my dns server using  and it rarely works Unable to post - login problems with Area 51 ... again I recently signed up for Area 51 with my stackexchange network account/ID, verified the account and logged in.  I see the main page  where I confirm that I am logged in.  I click on the discuss link on the black menubar at the top, which takes me to the discussion zone. From here I click on ask question, which asks me to add  a login even though I have already logged in with my stackexchange ID.  Here if I choose the stackexchange login option then it takes me back to the main page, from where the cycle begins again. Drive shape key based on relative camera orientation? This is a question from the free Harvard online abstract algebra .  I'm posting my solutions here to get some feedback on them.  For a fuller explanation, see  post.  This problem is from assignment $5$.     Prove directly that distinct cosets do not overlap.   Let $H$ be a subgroup of $G$ and let $a$, $b$, and $c$ be elements of $G$ such that $b\not\in aH$ and $c$ is in both $aH$ and $bH$.  Then there are elements $h$ and $h^\prime$ in $H$ such that $c=ah$ and $c=bh^\prime$.  So $ah=bh^\prime$ and $b=ahh^{\prime -1}$.  But $hh^{\prime -1}\in H$ so $b\in aH$.  This contradicts our original assumption. Therefore, there can be no element in more than one distinct coset.  Again, I welcome any critique of my reasoning and/or my style as well as alternative solutions to the problem.  Thanks. If every compact set is closed, then is the space Hausdorff? And now, for something completely different: The mushrooms are among us I'm talking about at least two juvenile sci-fi novels, read between second and fourth  public grades (U.S.A.) which for me places them around 1956-9.  The protagonists are a brother and sister, presumably my (then) age. They are friends  with a single man, a scientist who has built a rocket ship. The scientist is little fey,  physically; a (relatively) large, round head, balding, short in stature and striking long,  thin hands and fingers.  The rocket ship's final preparation is to slop a viscous, clear gloop over EVERYTHING, inside and out from a pail with a paintbrush. In flight, there is an encounter with the moon, and a very small planet with (non-threatening) inhabitants not physically unlike the fey rocket scientist. The planet orbits either the moon or the earth, not the sun, and strangely, some kind of mushroom(!) theme runs through the books. Really.  That's it. That's all I got (I was nine at the most, fer chrissake). My recollection tells me there was concealment from parents, a particular name for the planet and people  and flight through a spatial fog. I mention these things separately because I am less sure  of them than the previous two paragraphs. The author was blissfully unrepentant of the laws  of physics:  Earth gravity on a micro-planet, fog in space and super-gloop to ready the  ricketiest rocket. Worked for me.  I'm guessing even Richard, my previous mentor/savior might not be familiar with these.  Anybody? Author, titles? Or do you just recognize one of these? Proving the general limit $\lim_{n\to\infty} \frac{an+c}{bn+d} = \frac{a}{b}$ Black artifacts when looking through many transparent objects? Using v2.73, cycles and a very simple scene: an array of cubes, no big deal.   If I set the shader's material to transparent, the cubes in the foreground do become transparent but those far away in the back do not disappear completely and this strange dark things appear (visible in rendered mode and in final renders)    I've played with the clipping distance on the viewport and camera, but I can't figure out how to make those ghosts go away... If A and B are correlated with C, why are A and B not necessarily correlated? Ubuntu 20.04 no sound out of Bluetooth headphones Panasonic Eneloop BK-3MCC (4th gen) - where I can find maximum discharge current? Im looking for some official information source about maximum current for Panasonic Eneloop BK-3MCC rechargeable batteries.  All I found is , there is just 1 table (nothing about maximum discharge current), charge and discharge characteristics.  UPDATE LINK:   / edited - I fixed my mistake, I meant 6A not 8A /  There is discharge characteristic for 6000mA discharge. So... I can safely draw 6A from that AA cell? Searching for a string on multiple zip files My installer build "signs" a DLL using a Code Signing certificate during the build process.   I've noticed that if I try to build twice in succession, the second build fails because the DLL is already signed so signcode chokes. Obviously I can fix this by signing a copy of the DLL in the build, but the problem intrigued me:   Is it possible to "unsign" a DLL, and if not, why not...? FileZilla: How to copy files from one directory to another on the same server? I want to copy files from one directory to another on the same server using FileZilla. Please guide me how can it be done?