We assume the universe has been shaped by a explosion "Big Bang" but from what I understand explosions make the environment "not" homogeneous and "not" isotropic. If that's right how can we assume the universe is homogeneous and isotropic? or am I wrong about the meaning of homogeneous and isotropic?
TV documentaries invariably show the Big Bang as an exploding ball of fire expanding outwards. Did the Big Bang really explode outwards from a point like this? If not, what did happen?
Force a rebuild of the start menu program index/database in Windows 10 With Windows 10 Microsoft migrated to a database-ish solution for indexing programs in search and the start menu, rather than just using a /startmenu/ directory. AFAIK the exact implementation is still pretty unclear, but there is something along those lines.  Updating from 8.1 to 10 causes it to migrate everything from /startmenu/ to the new system, which ignoring issues such as a (seemingly arbitrary) cap of 500 applications, works fine.  However this failed for me, and from googling seems to be an issue from upgrading with an older dev build, which then carried on to RTM.  So does anyone know a way to force a rebuild/re-index of the program library? Rebuilding the system wide index through control panel (also in &lt;=8.1) has no effect. "It really doesn't matter" v "It doesn't really matter" Auto-fit TextView for Android How to prove $4(n!)>2^{n+2}$ for $ n\geq 4$ with induction I've done the base step, but how do I prove it is true for $n+1$ without using a fallacy? $$4(n!)&gt;2^{n+2}\quad \text{for } n\geq 4$$ Please help. Sum of $k$-th powers My daughter applied at the Italian Consulate in Philadelphia, and they gave her two entries for 20 days (we thought it was for 20 days each entry). She was in Italy 12 days, then went to England for 1 week and flew to Venice to take a 10-day cruise. She couldn't make it because they said she has only 8 remaining days, but she still has a land tour already paid this week.  What can she do? Can she extend the Schengen visa for 12 more days? Right now, she is in Madrid, but next week she has to fly from Barcelona to Paris to start with the tour. What would happen if she decides to take the tour with the expired visa? She is a US permanent resident. Is there a way to get new dwellers with higher than normal stats? Software for measuring internet traffic? I'm interested in finding a free piece of software for Windows XP &amp; 7 that allows us to measure both incoming and outgoing internet traffic, but not traffic between users of the local network.  I live in a shared household with three others, and we're interested to see which of us is using the largest amount of our monthly internet quota. We're all happy to install the necessary software.  Any suggestions? I was wondering if there is any rule in English that forbids us to say A Happy New Year when we wish someone Happy New Year? I know that we just say it like that, but I was trying to find the rule which would explain this. Thank you for your help. Deleting comments under posts in the mod queue should be easier Ever since mods gained the ability to undelete comments, deleting them has become easier as the confirmation dialog was removed.  However, this is not the case in the mod queue &mdash; I still get a confirmation dialog for each comment I want to delete in the queue under a custom-flagged post (single-comment flags can be deleted just fine). And since this is the place from where I delete comments the most, it can be annoying.  In addition, the "purge comments" button, when invoked from the queue, refreshes it, so I have to scroll back down, remember which post I just purged, and mark the flag as helpful. Usually not a big issue but if there are multiple "obsolete comments" flags, then it can get confusing.  Could the workflow for comment thread moderation from within the queue be improved? Ideally, make comment deletion work like everywhere else on the site, and make the purge button AJAX-based like the comment deletes. Where can I safely store my stuff? I'd like to find a place to store stuff while I'm out adventuring, without spending 5000 on a house (at least, until I can afford that...). Where can I safely store items without worrying about them disappearing?   There are two possible places that come to mind,  (to which I have the key and was told I could stay), and the small bedroom given to me at the  (which I was told was mine, despite seeing J'zaro sitting in it later). Can I store items safely in either of these places? Why not to extend the set of natural numbers to make it closed under division by zero? What is the probability that $x_1+x_2+...+x_n \le n$? Given that $X_1, X_2...$ are mutually independent random variables. For each $i$ with $1\le i \le n$   the variable $X_i$ is equal to either $0$ or $n+1$ $E(X_i)$ = $1$   also.. if $X_i$ is equal to either $0$ or $n+1$, doesn't that mean that all $X_i$ need to be $0$?  Thanks Trying to manually sign android package with jarsigner.exe and install with adb.exe Miraak is stealing all my dragon souls Comma with 'who' in this specific sentence Can you shed light into this?  The coach came to the defence of the player who has been sacked from the team following his differences with the captain.  OR  The coach came to the defence of the player, who has been sacked from the team following his differences with the captain.  Isn't the subordinate clause that begins with 'who', non-restrictive? Recently I've changed jobs, and consequently the field of research has also changed. But I'm still getting proposals for publications in the previous field, and it is interesting for me to accept some of them. My concern is about which affiliation to use: on one hand I gain all the knowledge in that field while working on the previous employer, also I hope they can cover my expenses related to the publication. On the other hand, I do not work for them anymore, and my current company has very little interest in my old field of research, and probably will not support it financially, but I think it is wise to mention them as well. As a compromise I'm thinking to put the previous employer in the affiliation, and the name of my new employer in the footnote, something like "currently at XYZ". Surely I'll discuss this issue with both, although the opinion of the community is also very valuable. British placement of punctuation relative to inverted commas Is liquid cooling necessary for high CPU performance over extended periods? I'm planning on building a system for high CPU and memory performance.  Graphics performance is not a major concern, as I do not plan to use it for gaming.  I noticed that liquid cooling seems to have become common since my last build, and I am wondering if it is needed in my case.  I do not plan to overclock any of the components.  The intended use for the system is primarily development and occasional compute-intensive tasks that will run on all cores continuously for several days to a week.  The system will not normally be in continuous usage like this, but it needs to be capable of occasional extended periods of continuous use at full capacity.  I have included the main components below.  CPU: i7-5960X  Memory: 64GB DDR4  Graphics card: Nvidia GeForce GT 730 2GB  Drive 1: 1TB SSD  Drive 2: 4TB 7200RPM HDD  Power supply: 700W  Is liquid cooling needed for the above build?  If not, is there any advantage in using it?  I have read reviews that mentioned liquid cooling unit failures that resulted in leaks, so I would rather not use it if it is not necessary.  Thanks! Does someone falling into a black hole see the end of the universe? This question was prompted by . Notoriously, if you calculate the Schwarzschild coordinate time for anything, matter or light, to reach the event horizon the result is infinite. This implies that the universe ages by an infinite time before someone falling into the black hole reaches the event horizon, so could that person see the universe age by an infinite time?  To be more precise, suppose the observer starts falling from rest at time $t = 0$ and some initial distance $r &gt; r_s$. If we wait for some time $T$ then shine a light ray at the falling observer. Will the light ray always reach the falling observer before they cross the event horizon? If not, what is the formula for the longest time $T$ that we can wait and still be sure the ray will catch the observer? If $T$ is not bounded it implies that observer could indeed see the end of the universe.  I can think of a qualitative argument for an upper limit on $T$, but I'm not sure how sound my argument is. The proper time for the observer to fall to the event horizon is finite - call this $\tau$. The proper time for the light ray to reach the horizon is zero, therefore the light ray will reach the observer before they cross the event horizon only if $T &lt; \tau$. Hence $T$ is bounded and the observer won't see the end of the universe.  I think a more rigorous approach would be to determine the equations of motion (in the Schwarzschild coordinates) for the falling observer and the light ray, and then find the condition for the light to reach the falling observer at some distance $\epsilon$ from the event horizon. Then take the limit as $\epsilon \rightarrow 0$. In principle this seems straightforward, but in practice the algebra rapidly defeated me. Even for a light ray the radial distance:time equation isn't closed form (Wolfram claims it needs the $W$ function) and for the falling observer the calculation is even harder.