Installing Ubuntu packages for dummies: Gstreamer plugins to play m4a files in Clementine?
How do I install applications in Ubuntu?
Domain Controller etiquette after a crash between Server 2003 & Server 2008 I have 2 domain controllers on a non-Internet connected network running Windows Server 2008 R2. They running RAID 5 on a 8 Hard Drive server. Sometime last week the Boot Sector became corrupt on DC1 and I was unable to recover the server. I am not going to have to rebuild the server. I have been reading about the changes from Server 2003 to Server 2008. DC1 was the main domain controller and now that it won't but it is all falling to DC2. I know that in previous versions of Windows Server you had to make on the primary and one the secondary. Since DC2 does not see DC1 anymore is there anything I need to do to DC2 as it is now the one in control? I am thinking some kind of meta data clean up but I can't find any hard information on what procedure to do. I understand as of Server 2008 domain controllers are on an equal footing and provide replication to each other so they should be the same correct? What happens when a familiar from the Find Familiar spell "dies"? In how many ways can $500$ indistinguishable students select books from $10$ titles if no more than $20$ copies of one particular text are selected? Assume that there are an arbitrarily large number of copies of ten diﬀerent discrete math books (which we will call titles) for cmsc250. Each student must choose one title as the course text book. Assume that the ﬁve hundred students taking the course are indistiguishable.  How many diﬀerent ways can the students choose titles, if Epp must be chosen by at most twenty students?   I understand that this is a stars and bars problem where the formula would be ${n+r-1}\choose{r-1}$, but whats throwing me off is the "at most" parameter of the problem. My answer is ${480+9-1}\choose{9-1}$ My reasoning was that we now have one less "bar", and that should be shown by lowering $r$ by 1  Am I approaching this the right way? Puppet client not connection to master - SSL connect Error I installed the puppet master and agent on the same machine. When the client is started, I got the following error message.  puppet agent --server=agent.com --no-daemonize --debug    err: Could not retrieve catalog from remote server: SSL_connect returned=1 errno=0 state=SSLv3 read server certificate B: certificate verify failed.  This is often because the time is out of sync on the server or client Uniform Circular Motion Why does the object not go inward, into the circle if the acceleration is inward? I think its because the velocity to outward? So they sort of cancel each other out? But if the speed is kept constant and the acceleration is inward, won't the object eventially move inward?   Also, what keeps the direction of acceleration always point inward? So I understand that Euclidean distance is valid for all of properties for a metric. But why doesn't the square hold the same way? Implementing toString on Java enums Nignx - worker_connections are not enough I don't know what is going on. I double value for worker connections but it still return error.  server { server_name xxx.com;  root /var/www/web; index index.html index.htm index.php; error_log /var/log/nginx/error.log; location / { proxy_http_version 1.1; proxy_set_header   Host $http_host; proxy_set_header   X-Real-IP $remote_addr; proxy_set_header   Upgrade $http_upgrade; proxy_set_header   Connection "upgrade"; proxy_cache_bypass $http_upgrade; proxy_pass         http://127.0.0.1:7777; }        listen 443 ssl; # managed by Certbot     ssl_certificate /etc/letsencrypt/live/xxx.com/fullchain.pem; # managed by Certbot     ssl_certificate_key /etc/letsencrypt/live/xxx.com/privkey.pem; # managed by Certbot     include /etc/letsencrypt/options-ssl-nginx.conf; # managed by Certbot     ssl_dhparam /etc/letsencrypt/ssl-dhparams.pem; # managed by Certbot  } server {     listen 80;     server_name xxx.com;     return 301 https://$host$request_uri; # managed by Certbot  }   Everything is okej with this code?  ERROR:  Firstly was:  worker_connections are not enough worker_connections are not enough   Now is  27513#0: accept4() failed (24: Too many open files) 27513#0: accept4() failed (24: Too many open files) 27513#0: accept4() failed (24: Too many open files) 27513#0: accept4() failed (24: Too many open files) Does the equivalence $$\neg\neg (P \rightarrow Q) \leftrightarrow (\neg\neg P \rightarrow \neg\neg Q)$$ hold in propositional intuitionistic logic? In propositional classical logic the equivalence holds obviously since $P \leftrightarrow \neg\neg P$. However, the similar-looking implication $\neg\neg (P \vee Q) \rightarrow (\neg\neg P \vee \neg\neg Q)$ is . The validity of the backward implication comes up in  as well. Fastest way to convert string to integer in PHP Neatest proof that set of finite subsets is countable? I am looking for a beautiful way of showing the following basic result in elementary set theory:     If $A$ is a countable set then the set of finite subsets of $A$ is   countable.   I proved it as follows but my proof is somewhat fugly so I was wondering if there is a neat way of showing it:  Let $|A| \le \aleph_0$. If $A$ is finite then $P(A)$ is finite and hence countable. If $|A| = \aleph_0$ then there is a bijection $A \to \omega$ so that we may assume that we are talking about finite subsets of $\omega$ from now on. Define a map $\varphi: [A]^{&lt;\aleph_0} \to (0,1) \cap \mathbb Q$ as $B \mapsto \sum_{n \in \omega} \frac{\chi_B (n)}{2^n}$. Then $\varphi$ is injective hence the claim follows. (The proof of which is what is the core-fugly part of the proof and I omit it.). This may be a stupid or trivial question, but I am new to Ubuntu, and have two unsolved problems (flashplayer doesn't play, and scanner doesn't work - in virgin install 13.04), so I started to search in documentation. In the 13.04 specific web site I was browsing the hardware section, and came across something like this: "Open Dash, and select Disk Utilities".  So what is Dash, and where is Disk Utilities?  The application finder could not find any of those. In terminal the "dash" command seems to invoke some sort of a shell. I wish to familiarize myself with the capabilities of QGIS up to and beyond QGIS version 3.0.   Can you recommend some good web resources and tutorials that would show me QGIS' capabilities?   I am interested in both using QGIS through its GUI and in developing applications using QGIS. Are bicategories and lax 2-categories the same? Choosing colors appropriately for red-green colorblindness I want a green for "correct answer" and a red for "wrong answer". My current choice is rgb(144, 238, 144) for the green and rgb(250, 128, 114) for the red. (See wikilearner.net/wiki for the colours in action.)  I have been told that these colors are very close in contrast, making it difficult for a person with red-green color-blindness. What would be a better choice? Conceptual half-life Question So I have this word problem and I’m a bit confused about it. I have the answer and explanation but I still don’t understand: The half-life of carbon-14 is approximately 5730 years, while the half-life of carbon-12 is essentially infinite. If the ratio of carbon-14 to carbon-12 in a certain sample is 25% less than the normal ratio in nature, how old is the sample?     A. Less than 5730 years      B. Approximately 5730 years      C. Significantly greater than 5730 years, but less than 11460 years      D. Approximately 11460 years  Correct Answer: A Explanation: Because the half-life of carbon-12 is essentially infinite, a 25 percent decrease in the ratio of carbon-14 to carbon-12 means the same as a 25 percent decrease in the amount of carbon-14. If less than half of the carbon-14 has deteriorated, then less than one half-life has elapsed. Therefore, the sample is less than 5730 years old. Be careful with the wording here—the question states that the ratio is 25% less than the ratio in nature, not 25% of the ratio in nature, which would correspond to choice (D). How is the ratio of the carbon isotopes relevant to half-lives? What is the purpose of saying the half-life of an isotope is infinite? What is meant by “the normal ratio in nature”? Just based on the answer, it seems like the question said “25% of a carbon sample decayed, how old is this sample?” Obviously it’s younger than 5,730 years (the time for its first half life) because if only 25% decayed that means half a half-life has passed. I don’t see how isotopes and ratios would change this problem at all. Edit: Every answer here was very informative and helpful. It was tough to pick a best answer. I picked Cosma’s because it clicked with me. If you’re reading this and want to understand radiocarbon dating, look at every answer because there is some useful information in every answer I am having trouble understanding the estimation of an AR process. In some textbooks, the AR(1) process is defined as follows: $y_{t}=\theta y_{t-1}+ϵ_t$ (which does not contain a constant). So the OLS estimator is biased. I am confused about the cause of the bias. It is explained that $y_{t-1}$ is dependent on $ϵ_{t-1}$ although it is independent of $ϵ_t$. However in linear regression, if the equation does not contain a constant, we cannot make sure the expectation of disturbance is zero. So the OLS estimator is bias without a constant. Does it mean that the OLS estimator is unbiased if I add a constant in AR process? How to add element by element of two STL vectors? Why is King Tommen Baratheon the "First of his Name" rather than at least third? What exactly is a kilogram-meter? This question isn't just about kilogram-meters, it's about multiplied units in general.  I have a good mental conception of divided units, e.g. meters per second or grams per cubic meter.  Meters per second just (usually) means how many meters are traversed by an object each second.  Simple.  But I don't really have a mental conception of what it means when units are multiplied, e.g. a kilogram-meter.  Can anyone explain in simple physical terms what a kilogram-meter is?