Is the PMP or other project management certification worth while to have?

Question: This is a classic question whose answer would likely help a lot of people on this site.
Is it worth it to get the PMP? How about other project management certifications?
Comment: Related question:  http://pm.stackexchange.com/questions/36/is-pmp-certification-an-appropriate-career-goal-for-someone-about-to-start-a-care
Comment: Does it help?  Who knows!  But it doesn't hurt. :)
Comment: Depends on the final goal. What is the overall life plan?
Comment: Opinion related. Unlikely to have value to the general reader.
Answer: Certifications of any type, whether for PM (PMP, PRINCE2), Computer Security (Security+) or Plumbing are of primary use to job seekers. It's an independent and objective assessment you can put on your resume to document that the certifying authority thinks you possess a particular skill.
The question a person needs to ask themselves is: what are they hoping to gain from certification?
I personally got my PMP specifically because I was considering changing jobs & I was looking to add a PM credential to my resume. I had been managing projects for over 10 years. I applied, bought Head First PMP, took a few free online practice exams and took the test. The certification provided exactly what I expected.
For a younger or candidate PM, I'm not sure I'd encourage them unequivocally to run out & get certified, unless they also considering a career change. The PMP is heavy on theory and light on practice - it reminds me of the CMMI that way. I've run across some PRINCE2 sites that deride the PMP for essentially capturing 'common sense' and little else. That said, because of the devotion to the PMBOK, which is an excellent set of practices, the PMP certification is of increasing value as the size of the project increases.
In a nutshell, I highly recommend the PMP or any comparable cert for job seekers. I would not recommend it outright for people wanting to learn the profession, but it's an option that you could certainly take.
Answer: There was a paper in the February 2011 issue of the Project Management Journal (Vol. 42, Nbr. 1): "PMP Certification as a core competency: Necessary but not sufficient" (pages 31-41). Although it was only a limited study, its' results are interesting.

The PMP Certification was the least valued of a list of 15 core competencies by professional IT recruiters. The most important where softskills like leadership, ability to communicate at multiple levels, verbal and written skills, attitude and the ability to deal with ambiguity and change.
There was no difference in project success rates between PMP certified and uncertified project managers.

I still value my certification because it gave me the opportunity to study the pmbok in more detail then I otherwise was ever going to do. Like all the rest, this is tacit knowledge I carry with me to do my job. But when people ask me about it I call it the cherry on the cake: it looks good, but it doesn't tell you anything about the cake :-).
Comment: Because the term "Last month" is time sensitive, could you please cite the issue number?
Comment: @user213: I have updated my answer. Thanks for pointing that out to me. I will keep it in mind.
Answer: I can't argue on the value to job seekers. But recently I had a fundemental Aha Moment that made me realize the value of certifications, if done right. I wrote a long blog on this, specifically in reaction to the recent PMI Agile Certification.
If you want to read the full blog, click on the URL below. The nutshell points to the US Incident Command System. A national system that allows multiple emergency service agencies to plug into each other and operate together on a disaster.
The can do it because of a common language and a common framework.
Certifications give you that common ground from which everyone can agree that the red cylinder thing is a fire extinguisher and not an upright vacuum cleaner.
Potato, Pahtato Gorilla- http://thegorillaisnamedhogarth.blogspot.com/2011/03/potato-pahtato-gorilla.html
Comment: +1 Good point, Joel. Effective communication relies on having a common language and certifications move everyone towards a standard set of terms.
Answer: I have completed my PMP certification in Oct-2010 and have few comments regarding its worth

In a world moving from waterfall to lean and agile the 42 processes and 9 knowledge areas may not make sense in all project management scenarios. That's the reason why I think PMI has realized it and has come out with an agile certification.
Having said the previous point I still believe for a technical person moving to PM role it provides a very structured learning methodology where you can understand and appreciate the different facets of project management especially topics like risk management and cost management which no one teaches you otherwise.
Also in the end any certification help you differentiate yourself from the persons with similar skill set, and demonstrate that you have invested time and effort in getting yourself benchmarked against some industry standard.
Answer: There are a few perspectives:

Looking for a job
In this case it really depends. There are some organizations which values certification highly and those which don't really care and won't pay you even a penny more because you have a bunch of certificates. Big corporations tend to be in the former group. I personally present the latter approach. You can either prove your skills during recruitment or no and your certificates don't change it.

Knowing the stuff
Whatever kind of certification we're discussing here it deals with specific methods, practices, principles and nomenclature. If everyone at your workplace follow specific method getting certification can help to sort all the stuff out and get you on the same page with others. Especially when the organization follows some approach rather conservatively.

Learning/becoming better specialist
That's where certification barely works. You can get most certificates pretty easily (PMP being rather an exception here). Having the certificate proves only you participated in some course (see: http://technicaldebt.com/?p=645). Even PMP with PDU mechanism doesn't really work well here. A bunch of PDUs is no confirmation that I'm better specialist or know more than someone who doesn't care about it at all.

To summarize: if your organization is orthodox in following specific method, certification might be quite a good idea. If you look for a job, think first what kind of job you're looking for. And if you want to learn I believe you can use the time much better than trying to earn a certificate.
Btw: so far I know no PM-related certificate which would work differently.
Answer: I have found getting a PMP is worth it to have if you think that the certificate will allow you to move up in your current company or you think that you would look for another position in the future.
Although I have found that solid experience is much more valuable than a PMP certificate, it certainly opens doors for you when job searching!
For more information, you can check out a few articles I've written here: PMP certificate- is it worth it?, and What to expect applying, preparing, and taking the PMP exam
Answer: I actually wrote a blog post about it. The summary of it is that I think it's worth it for me, but depending on your situation it might not be the best thing for you.
http://www.liquidplanner.com/blog/2011/3/10/pmp-certification-is-it-really-worth-it.html
Answer: PMP & Career Opportunity
PMP, per se, does not create any job opportunity. But it can help in enhancing your career. The scope of PMP is excellent. It is a well renowned & respected certification. According to various surveys, it is one of the top 10 certifications in the world.
PMP Scope
Many companies have made it mandatory for the PMs to attain a PMP or equivalent certification. You will find many JDs saying "PMP mandatory". If you do not have the certification then you are not considered for the PM designation. This might restrict your career progress.
Another reason to do PMP is salary. According to PMI's Salary Survey 9th edition - those with a PMP certification garner a higher salary (20% higher on average) than those without a PMP certification
You can also refer to PMI salary survey (http://www.pmi.org/learning/project-management-salary-survey.aspx) and check out the salaries for your geography and your industry.
PMP Requirements
There are 2 requirements to appear for the PMP certification -

Project Management Experience
35 hours of Project Management Education

Regarding Project Management Experience
You need 4500 hrs of PM experience if you have done 4 years of degree (bachelors degree or equivalent). Other wise if you have a diploma of equivalent then you need 7500 hrs of PM experience.
PM role is important for doing PMP - 4500/7500 hours of experience should be in leading & directing projects. However, PM role is not equivalent to PM designation/title. PM role means that you should have managed full or part of a project. PM role could mean vendor management, team management, client management etc. The projects could be related to any industry. They could be big or small, technical or non-technical etc.
You can read more about the details of PM experience here - questions on PMP requirements
Regarding 35 contact hours
This article that will tell you everything about PMP 35 hours training - The Complete Guide to PMP 35 Contact Hours
You can do self-learning online training to get 35 contact hours - Best PMP Online Training Course - 6 Popular Courses Compared
Or you can go go for an instructor-led online course - Best PMP Live Online Training - 6 Popular Courses Compared


How does the Sony 135 F2.8 [T4.5] STF twin aperture lens design work?

Question: I stumbled across the Sony 135 F2.8 [T4.5] STF other day.
I have read through the review but I can't for the life of me figure out what the twin-aperture setup is supposed to do!
Answer: From the article:

This lens has two apertures; the stepless aperture, manually
  controlled with the aperture ring, and the automatic aperture (A
  position), controlled by the camera. In the stepless aperture setting,
  emphasis is put on the aperture shape, which is rounder than the
  automatic aperture. For large aperture settings, selecting the
  stepless aperture is recommended.
Comment: See also http://www.the135stf.net/design.html
Answer: Basically there is a manual iris that is designed to produce as round an opening as possible in order to render out of focus highlights as circles (instead of pentagons, octagons, etc.)
Since the whole purpose of this lens is to produce smoother blurred backgrounds using the apodization element, it would be a waste if the effect were ruined by not having a circular aperture when stopping down slightly.
Presumably having this aperture stop right down would compromise its roundness, so they added a second aperture which can close all the way down for when you want a very narrow aperture.


Would a salt bridge work through which the ions could not diffuse into the half cells?

Question: Instead of covering the ends of the salt bridge in an electrochemical cell with a membrane, one could also plug them on both sides with a conductive non-porous material, for example gold, which doesn't go into solution. Would the accumulation of the ions at the plugs and their electrostatic force field be enough to keep the cell running?
Comment: In doing so, you will effectively split your electrochemical cell in _two_  independent cells, each having gold as one of their electrodes. Then you may apply the common rules to see if these cells will work.
Comment: I think the gold plugs would not act as electrodes - gold ions would not go into solution, and there is no wire between the gold and the other electrode. The plugs do not necessarily have to be a metal - I want them to be non porous and able to let the electric field through that the accumulating charges have. I think a closed glass tube would also work.
Answer: It is a very good thought experiment as to why we don't cap the salt bridge ends with gold plugs. By capping, you are essentially providing an interface which can source and sink for electrons in the cells, thus each end will act as an electrode in the cell. One end of the salt bridge will act as a cathode and one end will act as an anode (strange as it may sound!)
As to your comment above "I want them to be non porous and able to let the electric field through that the accumulating charges have. I think a closed glass tube would also work". No a close tube will not work. You need the ions or electrons to move in order to observe current flow. A closed glass tube will have an infinite resistance and hence no current can flow!
Comment: The ions inside of the closed glass salt bridge could move - and would polarize the solution inside the closed glass salt bridge by opposite charged ions accumulating in opposite ends.The opposite charges in the solution on the other side of the glass would mirror the charges and push up against the salt bridge. The resulting electrostatic field would be zero, I suppose. And that's what a salt bridge should accomplish. I am not sure I am right, so that is why I ask the question.
Comment: I upvoted your answer sometime ago. Of course, you are correct for the glass rod. I just did a *very rough* calculation assuming a "closed glass salt bridge" with electrolyte filling, etc., resulting in about 0.25 pF equivalent capacitance. Even if charged to 1 V, this is only about 1.5 million electrons worth of charge. The charging would take place very quickly and it would be a fairly finicky to measure. So, case closed as far as I can see!
Comment: Could you add your rough calculations as a separate answer? I think it be very useful. Thanks.


Unable to connect to authentication servers on debian vps

Question: I am currently hosting a server on a VPS running debian and when I try to connect to the server my client gets an error saying the authentication servers are down, and the server displays an error saying it is unable to connect to the authentication servers. I have checked the status of the servers and Mojang says they are up and running. I suspect it has something to do with the fact it is a vps and i need to add the authentication servers to a file somewhere in the OS to allow the server to connect I am just unsure where and how.
Comment: If you connect to your VPS directly (not with the MC client) and try to ping the Minecraft authentication servers from within it, what is the result?
Comment: Has it ever worked in the past?
Comment: No, the server itself had been copied from a windows machine and when it was on that it worked.
Answer: Some folks use VPS servers to try and 'crack' all kinds of authentication servers, including Mojang's. They're not really interested in Minecraft accounts beyond learning of an email / password pair that might work for other (more important) things like gmail.
It's not unlikely that the previous 'owner' of your VMs IP was engaged in those sort of shenanigans, and that Mojang inserted a firewall rule on their side to stop the abuse.
If that is the case:

Contact Mojang. Tell them you just bought a new VPS and it can't connect to their authentication server.
Be ready to back up that claim - keep the welcome email the host sent you
If all fails, try explaining this to your host, and ask for an IP from a different block

SSH to the VM first and try pinging / traceroute to the auth server, include this information when you contact Mojang.
When you get a shiny new VM, you also (unfortunately) inherit all of the bad behavior that might have been coming from the IP it was assigned - once in a while you have to play the it ain't me game to get stuff working again.
Comment: Wait, it is an answer, but you could simplify the first paragraph of it. It sounds like you are answering the question of "How do people steal my Minecraft Password?", but the rest answers the question here.
Comment: @ardaozkal I made an edit. I have to explain the phenomenon as context, but I think it reads more clearly now.
Answer: I had a similar issues.
The problem with all the fixes i found was that I installed Minecraft via snap. sudo snap install minecraft and because snaps are self contained the java on my machine did not effected it.
What fixed it for me was installing the old launcher instead.

Remove snap version sudo snap remove minecraft
completely remove java 10 ( If Installed )
Install Minecraft Via curl Script
Answer: I've had this issue before, turned out that whilst I'd created iptables rules to allow incoming connections to ports that the server used for the game, I hadn't allowed established/related connections coming back from the authentication servers.
If you are using iptables, you might want to check you have this rule on your input chain.
iptables -A INPUT -m state --state ESTABLISHED,RELATED -j ACCEPT

Check if you have any iptables rules using the command iptables -L
If this helps, these are my iptables rules (as seen by the command iptables -L), basically, it firewalls off all incoming connections apart from SSH (used to manage the server), http as I run a web server on the system, then I allow 25565 (Minecraft) and 25575 (rcon), and any other incoming traffic on the local network (192.168.1.0/24). I place no restrictions on traffic being output from the system, and note that I also allow all ICMP traffic through, which isn't essential, but it could cause problems if you block it.
root@mc:~# iptables -L
Chain INPUT (policy DROP)
target     prot opt source               destination
ACCEPT     tcp  --  anywhere             anywhere       tcp dpt:ssh
ACCEPT     tcp  --  anywhere             anywhere       tcp dpt:http
ACCEPT     tcp  --  anywhere             anywhere       tcp dpt:25565
ACCEPT     tcp  --  anywhere             anywhere       tcp dpt:25575
ACCEPT     all  --  192.168.1.0/24       anywhere
ACCEPT     icmp --  anywhere             anywhere
ACCEPT     all  --  anywhere             anywhere       state RELATED,ESTABLISHED

Chain FORWARD (policy ACCEPT)
target     prot opt source               destination

Chain OUTPUT (policy ACCEPT)
target     prot opt source               destination

Answer: I'm not sure if you are still having this issue, but I finally found a solution that works for me.  Along with making sure the iptables rules suggested earlier are in place, I had to add two java command line arguments.
-Djava.net.preferIPv4Stack=true -Djava.net.prferIPv6Addresses=false

After adding those in my java execution line, I was able to connect to my minecraft server running on my debian vps.
Answer: I had this problem on a new Digital Ocean box running Ubuntu 18.04 and tried a lot of things, but these steps finally fixed it.

Ensure you can access the following URLs from your box using ping, curl, wget etc.

minecraft.net
account.mojang.com (note, this will give you a 403 by default)
authserver.mojang.com
skins.minecraft.net
textures.minecraft.net

If you cannot, look at Tim Post's answer, if you can connect, continue.
Completely remove the currently installed version of Java from the box. There are complete answers online as to how to do that.
apt-get install openjdk-8-jdk. (I had java 10 installed from apt-get install default-jre and nothing I did would make that work.)
update-ca-certificates -f
Run the commands from this script
/usr/bin/printf '\xfe\xed\xfe\xed\x00\x00\x00\x02\x00\x00\x00\x00\xe2\x68\x6e\x45\xfb\x43\xdf\xa4\xd9\x92\xdd\x41\xce\xb6\xb2\x1c\x63\x30\xd7\x92' > /etc/ssl/certs/java/cacerts
/var/lib/dpkg/info/ca-certificates-java.postinst configure
reboot
Success!
Answer: I suggest that you completely re-create the server (using same map, etc.) since you just copied the files from a windows computer.
Server files that come from a windows machine CANNOT  be used on Linux unless you create a virtual machine.
You can download Linux server files from here under multiplayer setup:
https://minecraft.net/download
I hope this helps :)
Comment: The only possible problem with copying server files from Windows to Linux is having the wrong binary and failing to start the server at all, but the Minecraft server package is a .jar file that will run anywhere, not Windows-specific. Besides, the server is obviously running, just not authenticating.
Comment: The server launches and I can connect to it if I set online mode to false, but it just can't connect to the authentication servers
Comment: I would still suggest a re-install. Most bugs such as this one are solved this way...


Gnome-Shell 3.4 Themes not working in 12.04?

Question: Even themes advertised as Gnome-shell 3.4 compatible have graphical issues on Gnome-Shell 3.4. The main thing is that the text is black and nearly invisible, and the icons in the applications screen are crowded and in some cases overlapping. The themes did not do this before upgrade, and the default doesn't do it now. I am using user theme extension, and the themes I have tried are the Ambiance-Color set and London Smoke (both of which are advertised as 3.4 compatible).
Comment: Please add the method you used for installing you themes in your question (and what theme are you using?)
Comment: Edited, now can you answer?
Comment: This question appears to be abandoned and unanswered, could you perhaps add more detail to your question? If this question no longer applies then you can either delete it or answer it yourself if you've solved the problem.  This is to help with the Ask Ubuntu Clean Up. If you feel this question is *not* abandoned, please flag the question explaining that. :)
Answer: Here is the right way to get gnome-tweak-tool (advanced settings) to work therefore shell themes and extensions to work WITHOUT breaking your gnome shell
<code>sudo add-apt-repository ppa:ricotz/testing
sudo apt-get install ppa-purge
sudo apt-get update
sudo apt-get install gnome-shell-extensions
sudo apt-get install gnome-shell-extensions-common
sudo ppa-purge ppa:ricotz/testing
(type N and press enter at the end of the process)
</code>
Restart the shell (Alt F2 >> r >> enter)
Comment: Didn't work, and may or may not have broken my system (Some errors while installing, hopefully nothing serious). Appears to be fighting for supremacy with a package in a ppa I don't have.
Answer: Most of Gnome Shell themes are currently incompatible with Gnome 3.4, the same for some extensions.
You can look for updated themes on Deviantart for instance.
I'm currently using this theme which works pretty well.
http://www.ubuntuvibes.com/2012/04/orion-gtk3-and-gnome-shell-elegance.html
Comment: I specified in the question that these themes were 3.4 compatible.
Answer: Furthermore, first delete older themes in .themes directory before installing the new one, otherwise, it won't work.
Comment: Tried, both .themes and /usr/share/themes/, still got the graphical errors.


Are pine needles poisonous to goats?

Question: I'm finding seemingly contradictory information with a normal search (forums).  Many sources say that their own goats love pine needles and there's nothing wrong with letting them eat them.  Occasionally somebody jumps in to say that pine needles can cause a miscarriage in bred does.  I suppose both can be true.  Any reliable source of info out there?
Comment: Welcome to Sustainable Living! Although eating can be seen as a form of recycling, your question is much more about biology than it is about sustainability. Perhaps somebody here knows something about goats, but I think you'll have a better chance of getting a good answer at [Biology SE](http://biology.stackexchange.com/)?
Comment: I think it's a legit question about sustainability because keeping livestock is an important part of sourcing ones own food and that's a sustainable thing to do.
Comment: or possibly even the skeptics SE?
Comment: I would be surprised as I've seen a goat grab a lit cigarette out of a guys hand and eat it 'cherry' first. It seems to me goats have iron stomachs.
Comment: My friend requested all of his acquaintances deposit their christmas trees in his goat pen. The goats stripped them to trunk and twigs. They lived a long time.
Comment: I find this very interesting! Particularly as I want to plant a windbreak for our milk goats's pasture on our property and initially considered pine trees for it. But my neighbours who are cattle farmers had a lot of abortions in their herd that grazed in a camp that had a pine tree windbreak, ultimately they cut down the whole pine tree windbreak. I just figured that with goats and cattle both being ruminants, the similarity between the two species is too close for my comfort, and abandoned the idea of using pine trees. I have now planted a line of mulberry trees that the goats seem to enjoy
Answer: My father's goats love pine, not just the needles but the young and flexible twigs too. So much so that most of the pinetrees in the feeding area lost the branches under 1,5 meters or so.
They never had a miscarriage, but had a lot of false pregnancies. I do not know if those have anything to do with pine.
Answer: I have been told that pine is a natural de-wormer for goats. I always give mine a few descent size branches when they show signs of worms. They usually will try their hardest to get to the branches even when they have plenty to forage on. Never had any issues and the worm problem is usually eliminated.
Answer: There is quite a lot of info on the web in general, from this big list of poisonous and ok plants (repeated in various places with no source or attribution - pine is on the ok side). A more definitive answer comes from this summary of two research papers containing this excerpt:

No abortions occurred, however, toxicity was observed in the 3 treated groups. The pine tips were most toxic, the bark less toxic and the needles least toxic. Clinical signs of toxicity included muscular weakness, trembling, unusual stance, rumen stasis, bloating, opisthotunus, depression, loss of appetite, and death. Necropsy revealed no significant gross lesions. Pine needles, tips, or bark do not cause abortions in goats but are potentially toxic…"

My experience is that goats will eat pine trees if given the opportunity, so it's probably wise to keep pregnant ones away from the trees. But they do generally seem to prefer grass and trees with bigger leaves. My experience of goats eating young trees (including pines) suggests that that should apply to any tree you don't want the goats to eat. Note that goats are climbers, and will eat much more of the tree than you would expect, if they can get access.
Answer: Some pines can act as abortifacients and possibly cause renal damage because they contain isocupressic acid.
Ponderosa pine is the one I know of, because we have some near our goat pasture and have to keep them fenced out of it. I have heard that juniper and a few other conifers might have this problem too.
On the other hand, our goats love douglas fir needles and young bark, and have eaten it regularly for 9 years with no miscarriages.
Answer: Well, it seems a little is ok.
I think we have over done it with out goats, given them too much too quickly. Seems to be a problem with gut bacteria and not having time to adjust to the new feed.
We had 2 huge pines cut down in the yard and have been chucking branches into the goat pen all week, so they don't have much choice.
Bad move - our one doe couldn't get up last night and is very week and bloated, all the others look ok, but seem like they have slight signs of bloat and weekness.
There was a study that someone referred to in a post about this very issue, it suggested that the tips are the more toxic part, and if they have too much it's a problem.
Bottom line: I think if you have decent pasture they will eat a bit of everything. Don't feed them pine exclusively.
Comment: *There was a study that someone referred to in a post about this very issue*  Please add a reference
Answer: I have a goat that's been sick for years and the pasture she's in is in the middle of a pine forest (bull pine to be exact). Whenever she's out and about she always takes a nibble on some pine trees and it's impossible to get her away until she is satisfied. I found a way to use this to my advantage and even out the harmful with the helpful. I take molasses and glaze some over the pine trees, to single out the trees they like, and then I put about half a cup of loose minerals over it. It encourages them to eat their minerals and to lessen the amount of pine they eat.
Comment: Welcome to Sustainability.SE! Thanks for the answer, and this seems like a helpful tip -- however, how does this limit the amount of pine that the goats eat? Do they get full on the molasses, or does it make eating the pine harder?

Are pine needles poisonous to goats?


Caption YouTube videos that are not mine

Question: I need to caption YouTube videos that are not mine (I currently link to them).  I don't believe I can edit and add captions when I am not the original owner.  However, can I download a video and then upload it under my account?  Then I ought to be able to caption it, correct?
Answer: You actually don't need to download it.  You can use a free service called Amara (formerly called Universal Subtitles) to "caption in the cloud," so to speak.  Once you've completed typing the captions and syncing them to the video (again, in the cloud with their browser based interface) it will generate an embed code from Amara that you can put in the HTML of your preferred page.  It also does an interactive transcript.  Very nifty.
Comment: Welcome to the Web Applications Stack Exchange site. Please take the [tour](http://webapps.stackexchange.com/tour) as it will help you to _learn the ropes_.


Missing spark plug, broken rear timing chain guide?

Question: On a 2004 ford explorer v6. I had a mechanic tell me the rear timing chain guide went.
Upon getting my vehicle to the house I noticed a single spark plug sitting on the front deck on the plastic gutter piece, and looked at the engine to find a spark plug wire hanging free with an empty spark plug hole.
They told me they did the work I asked, and had it running, then it began to sound odd and stopped running.
Is it possible they screwed up?
Comment: It seems clear they screwed up by returning the car to you with a missing spark plug. I'd find another mechanic!
Comment: If you were missing a plug your engine should have been running extremely rough, did you notice this?
Comment: Yes all six are necessary, there are no spares.  I'd take it back and demand a refund.  I don't think I would give them another chance to "fix" it.
Answer: It's clearly an issue on their side.
A spark plug does not blow out of the engine alone, the spark plug would be shattered at minimum.
Get the best refund you can, reinstall the spark plug and try a different mechanic.
What I don't understand  is that you have been able to drive back home like this ?!


Trub versus Lees

Question: What is the difference between Trub and Lees?
I've only heard about lees in regards to wine, i.e. the leftovers in the bottle. Note, Wikipedia says Lees is not only leftover grape bits, but also dead yeast.
OTH, Trub is the leftovers after a homebrew boil. I've also heard the settled yeast after bottle conditioning called trub.
Could the bottle conditioning 'trub' also be called 'lees'? Is there a technical difference? Is there an etymological difference? (I realize that last question might be better fit for the ELL or English stacks, please advise)
Answer: Wiki says that trub is German for lees.
https://en.wikipedia.org/wiki/Trub_(brewing)

Trub versus Lees


mobile sites/apps and other things

Question: I honestly have only heard about this because of the tv show, the good wife.  I didn't know it was real. I am very curious as to what bitcoin is, can do and also, if there are mobile friendly apps and sites for the use of bitcoins. Also, explaining this mining thing a little better, would help. I am not sure how that earns me bitcoins or if I have to pay in with paper money to get bitcoins or if it is even legal to have bitcoins. (seeing that you have a siteshutdown is concerning to me with the fbi doing it). Anyway....thanks for taking the time to read this....I look forward to the answers.  Also....one last thing.....can I buy things like computers, software, cameras, editing software with bitcoins if I save enough of them?
Comment: Hi jason, welcome to Bitcoin.SE. Please have a look at the [about] to get a better understanding of how this site works: We are trying to build a good resource of questions and answers, which means that one is supposed to focus on one question per "question". Also, it is appreciated when the question shows previous research effort. Most of the questions you have asked have answers on this or other websites, for example have looks at [tag:mining], [tag:mobile], [How do you obtain Bitcoins?](http://bitcoin.stackexchange.com/questions/91/how-do-you-obtain-bitcoins).
Answer: That's lot of questions!!
The first thing I recommend is to browse the pages here: http://bitcoin.org/en/
As a bitcoin user/spender you don't need to think much of how mining works, just that they are crucial to keeping the entire system safe.
Other than mining you can get bitcoins from an exchange, or other services. https://localbitcoins.com/ is a site where you can find real people that sell bitcoins and you can agree to met someone face-to-face. An exchange can be thought of brokerage account, you can buy bitcoins for a commission the same way you would buy company stock.
There are a lot of different things you can spend bitcoins on, must of it are online. For real shops that accept bitcoin this site http://coinmap.org/ will guide you
Obviously there is a lot more to be said but I recommend you to start reading. This forum is more for technical questions on the bitcoin network I think but there are other forums for miners, users, investors etc.

mobile sites/apps and other things


Inflation from a cold wallet?

Question: Is there a good way to make a wallet a cold wallet after setting the inflation destination? That is, if I have a wallet and set the inflation destination to a pool so I will accumulate inflation, can I still make that wallet "cold"?
Answer: Stellar doesn't have such concept as "cold" wallet. Once your wallet is created and funded, the public key and current balance are recorded on the ledger. If your private key securely stored somewhere (encrypted flash-drive or hardware wallet like Ledger Nano S), you shouldn't worry about the funds.
In order to enhance your account security, you can add one more signer and set all account thresholds to 2. In that way only those persons who have both private keys can authorize a transaction. However, multi-sig is not supported by most wallets so far, and if you choose this option you'll have to dive deeper into the Stellar docs and use Stellar Laboratory instead of a wallet with fancy interface.
Answer: Just create a paper wallet (paper, pendrive, ledger nano, etc), add some funds, set inflation destination and that's it. Even if you don't touch your account for years inflation will get to the ledger and increase your balance.
<code>function setInflation(secretKey, destination, memo='Inflation') {
    var serverUrl = 'https://horizon.stellar.org';
    var server    = new StellarSdk.Server(serverUrl);
    var account   = StellarSdk.Keypair.fromSecret(secretKey);

    server.loadAccount(account.publicKey()).then(function(sourceAccount) {
        var operation   = StellarSdk.Operation.setOptions({inflationDest: destination});
        var transaction = new StellarSdk.TransactionBuilder(sourceAccount)
            .addOperation(operation)
            .addMemo(StellarSdk.Memo.text(memo))
            .build();
        transaction.sign(account);
        server.submitTransaction(transaction);
    });
}
</code>
Comment: Nevermind - found the answer re: setting inflation destination on a cold wallet here: https://stellar.stackexchange.com/questions/38/how-do-i-select-an-inflation-destination?rq=1 SO - I am accepting this answer with the additional description on how to set the inflation destination. Thank you!
Comment: So how do you set the inflation destination for a paper wallet? My best guess is you need to set up a connected account, set the inflation destination, and then print the key/password combo and delete the account from the connected wallet. Or is there a way to set the inflation destination without having the wallet online?
Comment: Added some JS code for reference

Inflation from a cold wallet?


cesium quantized mesh generator

Question: We are trying to develop pur own quantized mesh generator and visualize these terrain tiles on CesiumJS. As an input we use SRTM data that belongs to north parth of TURKEY. We generate contours on DEM, extract points from contours and triangulate points using Delanuay algorithm. Finally we tile data according to TMS specification and encode data to terrain files. When we attemp to visualize these terrain files on CesiumJS, we receive some errors. We tile data for zoom levels between 10 and 16 because our region is relatively small compared to world. But while we are zooing to our region cesium requires tiles that are not in our zoom range and after a while when we keep zoom in everything disappears. We couldn't figure it out why this happens. Here is some pictures describe situation before and after a zoom.
Comment: Does it help if you provide some simple tiles for the zoom levels outside the range of your project? For example using only the continent boundaries from https://www.naturalearthdata.com/
Answer: The open source project Tin-Terrain might be of help. It is a simple command line tool that we have just released. It will generate quad-tree tiled TIN quantised meshes that are directly compatible with CesiumJS.
Comment: [**Avoid overt self-promotion.**  The community tends to vote down overt self-promotion and flag it as spam. Post good, relevant answers, and if some (but not all) happen to be about your product or website, that's okay. However, you *must* disclose your affiliation in your answers.](https://gis.stackexchange.com/help/behavior).  In practice this means any answer that recommends your own product must include something like "**Disclosure:** I am the [position] of [company] that develops/distributes this software".

cesium quantized mesh generator


Authentication by delegation: what does it mean?

Question: What does "authentication by delegation" mean?
Answer: It means that you delegate the responsibility of authentication to a trusted third party. In practice, when using google as an OpenId provider that people will use to log in to your web site you are doing delegated authentication.
Answer: It means that you are trusting the word of someone else when they assert the identity of an entity. It is generally established to be safe to do this by a cryptographic relationship, e.g., the assertion is signed with a private key that you know only they (should) have, and you can use their public key to verify it.
Answer: I think it depends upon context.
The phrase makes me think of impersonation in Windows operating systems.  Here delegation allows the server implementing an RPC service to assume the identity of the caller - subject to some infrastructure constraints.  When an RPC call impersonates the caller, it is trivial to establish the identity of the caller, since it is inherent to the current execution context, and can be acquired (at a low level) from the current thread token.  I'd argue that "authentication by delegation" probably refers to this pattern of authentication subject to the typical facilities offered by Windows systems (be that using [D]COM or WCF or native Win32 calls.)
http://technet.microsoft.com/en-us/library/cc961952.aspx


Inner product in QFT

Question: When we write inner product in QM for example $\langle\psi\rvert x \psi\rangle$it means (in position space) $\int\psi^*(x,t)x\psi(x,t)dx$. But when we write, in QFT, $\langle0\rvert0\rangle=1$ what does it mean? As $\rvert0\rangle$ stands for vacuum state and since there is no particle as of now (since no creation operator is operated on it yet), why are we choosing it to be one?
Comment: The vacuum state still has to be normalised ...
Comment: @JohnRennie yeah it has to but if I think about vacuum it reminds me of just empty space with zeroth energy level so idea of normalization sounds a bit weird to me. Like in QM we back the normalization by giving a physical argument that particle has to be found in between $-\infty$ and $+\infty$ but what to say when we are dealing with the vacuum.
Comment: Possible duplicate: https://physics.stackexchange.com/q/8602/2451 and links therein.
Answer: In the standard treatment of quantum field theory, states are treated as abstract vectors in a large Hilbert space (specifically, a Fock space), and no "wavefunction" interpretation is given to them like it is in 1D quantum mechanics.
For applications to black hole physics (and other areas of quantum gravity), however, one often refers to the "wave functional" (the probability amplitude for the field to be in a specific configuration) $\Psi[\phi(\textbf{x})]$, for which a matrix element is written as a path integral
$$\langle\Psi|\mathcal{O}|\Phi\rangle=\int\mathcal{D}\phi(\textbf{x})\,\Psi[\phi(\textbf{x})]^*\mathcal{O}[\phi]\Phi[\phi(\textbf{x})],$$
which is calculated in perfect analogy to expectation values in 1D quantum mechanics.
When we write $\langle 0|0\rangle=1$, what we're saying is that the vacuum wave functional $\Psi_0[\phi(\textbf{x})]$ is normalized with respect to this (somewhat ill defined) inner product.
Answer: There is no physically-meaningful relationship between the norm of a state-vector and the number of particles it contains. QFT is not constructed in terms of particles anyway; it is constructed in terms of quantum fields. Particles are phenomena that the theory predicts. The vacuum state is a physical state defined to be the state of lowest energy. Particles are defined relative to the vacuum state, and the vacuum state has no particles by definition. A typical state in QFT does not have any well-defined number of particles.
(By the way, the meaning of "particle" becomes even more blurred in QFT in curved spacetime, where there is no longer any obvious way to choose which state to call the "vacuum".)
Only non-zero vectors in the Hilbert space can be used to represent physical states, and a non-zero vector has a non-zero norm. Just like any other physical state, the vacuum state is represented by a non-zero vector in the Hilbert space.
As Bob Knighton's answer highlighted, we can use a representation in which a state-vector is a function of the field variables, and the field operators are differential operators acting on those functions. A simple but explicit example of a calculation using such a representation can be found here: https://physics.stackexchange.com/a/439381/206691. A famous published example can be found here:

Feynman (1981), "The qualitative behavior of Yang-Mills theory in 2 + 1 dimensions", Nuclear Physics B 188: 479-512,
https://www.sciencedirect.com/science/article/pii/0550321381900055

To help emphasize that the vacuum state should be regarded as a physical state (and therefore should be represented by a non-zero vector in the Hilbert space), remember that even "empty space" always includes a non-zero metric field. Flat spacetime is no exception. We usually treat the metric field as a prescribed background in QFT, not as one of the quantum fields, but it is still an essential part of the model. Even though "empty space" might not have any particles, it always has at least one entity (the metric field) that is "physical" in the sense that it would interact with other fields and particles if they were present  — at least it would in the real world.

Inner product in QFT


How to mine with NVidia GeForce GTX 560Ti on Linux?

Question: The questions is in title. Been surfing a bit, and I'm not aware of any software which allows mining with Nvidia GPU on Linux.
Answer: We support with xmr-stak-nvidia all gpus from fermi up to the current available pascal generation.
Answer: Your video card is old and may not be supported. Fireiceuk have released an xmr nvidia miner and may support it. You can try and install it https://github.com/fireice-uk/xmr-stak-nvidia. Lastly, this can be really problem for you when installing the required drivers for nvidia.
Answer: https://github.com/KlausT/ccminer-cryptonight/releases
not positive if the 500 series is supported, but it's what I'm using for nvidia on linux currently


When is it best to use a Rainbow Table attack?

Question: Under what circumstances that a Rainbow Table attack is best used?
Comment: We generally ask that people have done some research before asking here. I googled "Under what circumstances that a Rainbow Table attack is best used?" and got a ton of high-quality hits. If you did that research and still have questions, then please refine the question to include what you do understand and where your confusion is.
Answer: Given that a Rainbow Table attack means that one must first precompute and store a lot before the attack can be done, it is best used when this trade-off is doable and it is worth the problem. This means for once that everything precomputed fits even into an acceptable storage. Additionally the rainbow table  should get used many times, so that the huge overhead of precomputing once gets pays off by using it a lot.
A typical example where this works are breaking unsalted password hashes: the hashes for typical passwords can be precomputed once and then used again and again to crack new password dumps. That's why unsalted passwords are a bad idea.
A typical example where this does not work are properly salted passwords: with the random salt one needs way more time and memory to store all possible hashes for a typical password and this effort does not pay off. That's why random salting is the usual way to defend against rainbow table attacks.


open tunings for bass?

Question: Long time bass [hack] player, also play a little bit of guitar, working on learning some music theory to expand my understanding of the mechanics of creating music. I'm curious about open tunings on both bass and guitar. Since I have a strong fondness for blues & slide guitar, I'm finding more and more references to open tuning. What are the major reason(s) for doing this? Can open tuning(s) be used on the bass as well as the guitar? Thanks for the assistance -d
Answer: There are a couple reasons that one might use an open tuning but the most common has to do with chords.  As you may well have noticed, certain chords are much more comfortable to play than others and some chord voicings just can't be accomplished.  Open tunings allow chords to hold a different shape on the guitar, which can make some chord voicings easier or actually possible.  Open tunings or alternate tunings can also allow for some monophonic lines to be more easily played and can be used to allow open strings to be incorporated.  Some will also say that open tunings will change the tone of your instrument to some extent, which is certainly true since you're essentially changing the tension of the strings, which affects tone, but most professionals will have their alternately tuned guitars all set up for that specific tuning; a setup of this nature would usually change the gauge of the strings to accommodate the needed frequency and maintain the instrument's intended tone and sustain, as well as considering the tension that the strings put on the instrument.
In a traditional approach, the bass doesn't typically play chords, so most of the value of an open tuning is lost, but not all of it, though it may just be categorized as an alternate tuning without playing chords.  Since the bass is usually playing monophonically, your alternate tuning considerations would be focused on playability and whether or not you want open strings included.  If you are consistently playing certain types of patterns that are hard to accommodate on the bass, an alternate tuning might be able to help with that.  This could also be a means of writing something different than you usually would (if you're writing), as we humans tend to fall into habits/patterns and those patterns are often influenced by the amount of effort/comfort involved in accommodating them.  So, a change in tuning will make some options easier and others harder, essentially forcing you to either do something new or find a new way to do the same thing you did in the original tuning, both of which can be a great exercises for your musicality, and your brain in general.
There are those bass players that play chords, myself included, and an open tuning could very well be great for those players.  Beyond the fact that low frequencies tend to get very muddy when used for chords, bass is a lot more difficult to physically play chords on due to the size of the instrument and its strings, as well as the scale length being longer, making it more difficult to get the same fret range that you would on a guitar.  An open tuning or alternate tuning could help reduce the physical strain of accommodating chords by allocating some notes to open strings, or changing the location of a given frequency to be included in your chord, which can reduce the stretch needed to reach it, or make a given note not need to be barred, as barred chords on bass are particularly uncomfortable.
So generally speaking, I don't typically see open tunings for bass, though I have seen alternate tunings.  For example, the bassist for Tool uses DADA (not sure if he always does or just for some songs though).  I also have a 6-string bass that is tuned from D-Eb (tuned in fourths) but that just affects the overall range of the instrument and not the playability or comfort level of a given chord or interval.  It could be fun to experiment with but if it were more useful, it would probably be a lot more common than it is.
Comment: Interesting and thoughtful ... Thank you! Re: habits/patterns - I'm recovering from wrist surgery, and finding positions that were comfortable in the past aren't comfortable (or possible in some cases) ... so this is an interesting and perhaps practical application.
Comment: @David - That might just be the sort of solution that you're looking for.  I've had wrist issues myself (fortunately no surgery required), which are probably at least partially the result of my playing chords on bass.  You may also want to sit down with an instructor, if that's something available to you, and they can make sure that your technique is proper.
Comment: Improper technique can cause a lot of issues.  Try to position yourself so that your wrist is as straight as possible.  This may call for raising the bass by adjusting your strap.  Look up some Classical guitarists and notice how they sit and how the guitar rests.  They most often have the guitar resting on their left leg, unlike most others who place it on their right leg (for right handed guitars) and they will have that leg elevated with a stand under their foot.  All of this is to promote a healthy posture and cause as little physical strain as possible, ensuring a long musical career.
Answer: tl;dr; "open-tuning" means that the open notes are in key (are in "tune").
If you're mostly into blues, then you're probably looking for interesting tunings for a blues minor pentatonic scale.  In this case, I'm inclined to agree with @Basstickler.  If you'd like to play around with other scales, you might be interested in a open tuning for that scale.
Check out this image (that I borrowed from this answer):

I will mainly talk about guitar here, but we'll never mention a chord, so this all applies equally well to bass.  To relate this to bass, just look at the EADG strings.
These notes are in the A minor pentatonic scale.  There are two cool things about A minor here - it's very popular in blues music and it has a lot of notes that happen to be open on a standard guitar tuning.  This last feature makes playing in this key extra-flexible because you can now hit notes that might be otherwise be difficult to reach from a given position, and also extra-forgiving, because you can always just stop fretting and keep strumming/picking/slapping away and you're still in key.
Of course, A minor pentatonic isn't the only scale that has lots of open strings on a guitar or bass.  There are other scales as well.  More to your question, there are also many keys for which notes on the open string are not in key.  They're way out of key.  One example of this is Bb minor (check out that 1st fret in this image that has exactly 1 note [or 0 notes for bass]).  This means that you basically gotta have your fingers on the board at all times when playing Bb minor.
However, if you tune each string on your guitar up by one half step (E# A# D# G# B# E#), then Bb minor has lots of open strings.  In fact, it's all the same fingerings as A minor was in standard tuning.  Bb is A plus one half step!
Similarly, from the picture we see that A minor has one string (B) for which the open note isn't in key.  You could make it be in key if you liked, by simply tuning that string up one-half step (imagine moving the whole B row in the image one step to the left).  Now we can also pluck the B (now the B#) string open and be in key.  Of course, this maybe complicates other fingerings you'd like to have in this scale.
This "open-tuning" thing doesn't only work for the minor keys, though.  There are many, many, many well used and loved scales.  Some of these may coincide with having many or all of the open notes in a standard tuning.  Many more will coincide with having many or all of the open notes in a custom tuning, if you'd prefer having open notes be in key.
Answer: One reason for alternate tunings, especially with slide guitar, is to reduce the interval distance between strings, so that a melody or scale can be played with less movement of the slide.  This can also be an advantage on bass, where the scale can make it hard to reach some intervals.
I was playing slide guitar with Open-D (Vestapol) tuning [DADF#AD] when I picked up bass, so I ordered a custom set of bass strings from Kalium to tune the bass [DF#AD]. (Intervals between strings are major third, minor third, and perfect fourth.) Worked well for me, being familiar with the chord shapes already.  Of course it makes it less convenient to reach wide intervals, but I generally prefer close intervals anyway.
Answer: From a slide perspective it becomes obvious: a slide is straight, so complex fingerings are impossible. Instead, you tube the strings so that the chords you want are able to be "fretted" by a straight bar.
Even if not using a slide, open tunings can sound quite different when you play chords.
Yes, you can use open tuning on a bass - it's not quite as relevant, as basses are tuned quite simply (guitars are tuned the way they are to make chords very accessible, and this isn't as necessary on a bass)

open tunings for bass?


User reports a bug, send it to QA first or Programmer first?

Question: We have a live SaaS product and users report bugs sometimes. We have a functional tester and a programmer. When a user reports a bug should it go directly to the programmer or should it go to qa first and must be reproduced by qa before going to the programmer?
Comment: This question is highly contextual. Can you provide more details on the problem that you are experiencing in this regard?
Comment: If you don't have either, you really should decide who is in charge of that kind of thing.  I would dump it on QA.  A lot of times the issue is user error.
Comment: Do you have a level 1 or level 2? (Support) They really should be reproducing the bug,
Comment: " I pay the programmer much more than testers" I wonder if that affects the number of bugs your customers are finding.
Comment: Unless specific house procedures say otherwise, don't you think programmers are there to do things, and QA people to decide whether things should be done?
Comment: I am the PO and go through all bugs before sending it to the programmer. I do not test the bug but I do make sure it is a legitimate issue before sending it over. I guess the problem is that some bugs are easy to find the cause and some are not. I don't want QA wasting time trying to reproduce it if the programmer could look at it and know what changes he did last that could cause it. At the same time I don't want the programmer spending countless hours trying to reproduce it either. I pay the programmer much more than testers so there needs to be a good balance.
Comment: @alephzero Of course. Paying the programmers more gets you better developers gets you code with fewer bugs. Paying QA less gets you less good QA which lets more bugs slip through.
Comment: If user-error hasn't been ruled out yet, definitely give it to QA first. But it looks like you should consolidate this into a workflow. Don't micro-optimize your bug-handling.
Answer: It depends
Each company has its own process for handling customer-reported defects. The one I'm most familiar with is more or less as follows:

Customer support person attempts to reproduce defect and updates the report with any extra information
Customer support or product owner searches defect management tool to determine whether or not the defect has been reported previously. In a large/complex application, it's not uncommon for multiple reports of the same problem to be made
If at this stage the defect is determined to be a true defect, the report is turned over to the product development team. It may go to testing for more detailed reproduction, it may go to development for correction, or it may go to a general backlog for grooming and estimation.
An emergency will often go through immediate reproduction, estimation, and be scheduled for fix as soon as possible in order to minimize customer problems. Less critical defects go through the normal estimation and scheduling process.
If the defect is an emergency fix, it may be released in a patch deployment, depending on the current release schedule and whether the fix needs to go out immediately.

Some other factors that affect how customer-reported defects are handled:

If the software is not a multi-tenanted SaaS offering, a special patch version may be offered to the customer(s) affected.
If the software is multi-tenant, and has the ability to handle a/b feature enablement (i.e. a change for the software can be rolled out to a small subset of users while the rest continue to use the prior version), the fix may be made available to only that customer to allow for more detailed checking that the fix does not cause problems for other customers.
If the customer has a history of reporting requests for changes to current features as bugs, the changes may be made as a bug fix but not prioritized for immediate release (customers like this happen. Sometimes far too often).

This is a long way from a complete list, but it should give you some idea of the decisions that go into what happens when a customer reports a defect.
Comment: The problem with these kind of bureaucracy instead of letting devs figure out what is important is that the most important problems are often hidden because people fail to see the importance/implications. Take grindr for example: https://www.troyhunt.com/hacking-grindr-accounts-with-copy-and-paste/ - I can bet the fix was really easy. But QA instead blocked any direct talk between customers and development.
Comment: @paul23 - I've had my own issues convincing devs that something is important (a rather nasty privilege escalation bug) and I *am* the QA, so it's not simply that. Our team does bypass the bureaucracy for critical problems - and for some issues, we've gone through the entire process in a couple of hours, then run a post mortem to find out how everyone missed something that nasty.
Answer: It depends on your policy if you have one. It could go either way.
It could also be that it goes to the PO and they should approve it before continuing with the fix or putting it in the backlog.
Comment: Agree. It depends on the firm or project guidelines. I worked at 1 project where a 3rd party group of testers was assigned to test system and the norm was to assign defects directly to developers. Only after 2 weeks, we were getting over 100 defects each week and most of those were invalid(invalid data or raised due to invalid scenarios or system or domain knowledge). 'Standard Policy' was changed to assign it first to PO/BA to have a preliminary check.
Comment: I think this question is asking for ideas on how to come up with the policy?
Comment: All the bugs are approved by me (product owner) before they go to the programmer. So they are legitimate issues reported by users. I am just running into issues where the programmer assigns it back to me saying he can't reproduce. I think a lot of the problem is we do not have the proper tracking in the app like analytics to help with the issues. I think we need to implement better tracking, Have the programmer be the first person who receives it and then if he can't reproduce or doesn't know what could cause it after X amount of time he should send it to QA. Thoughts?
Comment: @RustyCraig I think Kate Paulk's answer goes in much more detail and it already covers anything else that comes to my mind.
Answer: It depends on the company to company and it's organizational work culture.
In my current and previous companies,
When a end user reports a bug first it goes/assigned it the QA team.
Then the QA team tries to replicate it in lower/Test environments (sandboxes).
If it's a valid issue then QA team documents the exact steps to reproduce it and after that it get's assigned it to the Developer/programmer for resolution/fixes.
If it's invalid then the same will get communicated to the user. This process will reduces the programmer's time.
Answer: First of all users should report using a reporting system, they should not be aware where does it go.
From there it depends on the size of your company, the product and how mature it is, the SLA you promise, the resource the company have and the kind of issues you expect.
Some examples I've seen over the years-

A big financial company, all user issues are passed through a first level line of  responders capable of solving simple issues since they assume most issues are actually user errors, configuration errors or people not reading the manual. Product managers are alerted on the more serious issues and they do a first triage as to where to forward it.

A small startup delivering a new innovative service, they have only one tester that don't have the bandwidth to look at user issues so developers check the external issue board every morning, if a problem seems to require reproduction the tester will help with that.

A medium sized company delivering safety critical software, issues must be solved quickly so the entire development organization are doing an on-call duties checking each issue as it arrives. If a problem arrives during work hours the person on call will try to triage it and request a tester's assistant if it is too complicated to reproduce.

A huge company delivering free and very popular service, issues are reported through a community forum, many of them are answered by community members. Product managers or people in special roles monitor the forums and locate problems that requires the developers attention. A mail is sent to the entire relevant team and the team is responsible to choose who will triage it.
Answer: Generally, there are 3 "stages" in handling a bug report, even if they are all carried out by a single person.  These are:

attempt to reproduce the bug, determine if it can be reproduced as is or if more information is needed, what steps need to be taken, is it just user error etc.
decide if this is behavior that needs correcting and if so how urgent / important it is
if a real problem was identified and when the priority demands, fix the problem and confirm that the behavior identified in step 1 no longer produces the error, and check if other non-standard behavior has been introduced.

In a lot of small companies with few developers there is a tendency to jump straight to stage 2 - the developer assumes they know what the bug is (often assuming user error is most likely) and decide if it is worth following up before even trying to reproduce it.  They will only then go back to stage 1 when (and if) they go to fix it.  If a bug report goes to the tester first, they are more likely to carry out stage 1 so that is one argument for sending all reports to the tester first.  However the tester may then be spending a lot of time trying to reproduce a bug that the developer can instantly say "that's a limit on the XY system" or "yes, I know that, it's a side effect of something already on the fix list"
So I would suggest both developer and tester seeing the initial bug reports and hopefully communicating about them, but then tester has the initial responsibility of reproducing / confirming the bug before it is evaluated for Stage 2.
Answer: To add to the "it depends" answers, I'd say the primary metric for determining an appropriate process for your company/team is what's going to get the issue resolved the quickest for the stakeholders (both the end customer as well as the company)?
For me, that would mean determining what's going to get the issue triaged accurately and appropriately (i.e. is this a rare edge case that only affects a single customer, something that affects everyone but has a clear workaround, is it something that needs a hot fix ASAP, etc).  Downstream from the triage, i.e. getting the bug fix prioritized, worked on, etc are other steps to also define, but figuring out the best way to triage the bug is the first step.
Comment: The OP should ask their staff first. Maybe they're lucky, and the tester and programmer are happy to figure out a workflow that gets things solved quickly and effectively.
Answer: In general the programmer is a more skilled and more expensive workforce than a tester. Therefore, in my opinion, for an optimal division of work, the tester should receive all the bug reports. The tester should then handle those bugs he/she can solve him/herself and only pass the hard ones over to the big guns/the programmer. This way the programmer can spend more time what he/she is supposed to do, programming.
Answer: In an ideal world? Your support escalation process involves checking for reproducibility; user error is common enough that you don't want to be spending either QA or dev or PO/BA assets on filtering the simple stuff out.
However, you also never want to tell a client "we can't reproduce it, we're ignoring this". People are distinctly not fond of being gaslit, and that is how it will come across. Once obvious user error has been ruled out and support has escalated it to their highest tier, the next step is generally one of four things… and which of the four happens should, ideally, be somewhat context-sensitive:

If there is reason to suspect that it should be reproducible but they can't figure out how, flag a QA resource to help with a brief consultation. This path is about leveraging QA's extensive experience with how to exercise corner cases of the system, and is especially useful if the client was trying to "do something weird" that is particularly likely to have exercised less-used parts of the system.
If there is reason to believe that it may not be a supported use case for the system, flag a PO/BA to check whether it is an actual bug, or just a lack-of-feature. With well-designed software this should actually be fairly rare, because the system should clearly inform the user that what they're trying to do isn't supported (yet), but there's always something that slips through.
If it seems "just plain old weird" or if there is something unexpected such as a stack trace (i.e. "something that really should never be sent to a client in the first place"), flag a dev to come do an over-the-shoulder check. Many companies choose to have an on-call developer as the technical / internal escalation point out of support (as opposed to the managerial / "the client is screaming bloody murder and lawsuits" escalation out of it).
If all else fails, especially if it hit either path 1 or path 3 and they need to escalate further, call in your guru / "troubleshooter". This is the person in your organization who has a near-mystical ability to look at even the most complex problems and at least have some idea what could be going wrong and how to start trying to diagnose it. If you don't have one and your organization is of any significant size, you should budget to fix that. You won't need them often, but when you do they will absolutely save your bacon. Note that while this may happen to be "a senior dev", usually they are closer to DevOps, because resolving problems that reach this level often requires a diversified background.

Since you mention that it it a SaaS product, I will say that you really, really need a proper set of analytics tools. And probably to spend the dev resources to get them wired up "fully", although even just getting the basics in place will help more than most folks realize. Without these, trying to diagnose any complex problem in a SaaS environment is at best far more painful than it needs to be, and at worst simply implausible (or even truly impossible) to do.
Answer: When a user reports an issue it should be reviewed and ideally recreated by the QA/Tester prior to the developer being exposed to it. Unless the user is a code-level expert in the software they will be reporting only from their sphere of knowledge. Any developer encountering the defect directly would need to recreate the issue prior to fixing it. Having what could effectively be called a QA-Layer between user and code would ensure the defect is correctly reported, enabling it to be fixed and released in a timely manner.
Answer: This sounds like you are missing a production support/issue tracking process, as production issues should never go straight to dev or test.
Even if there's not a person playing the formal support role, a good issue tracking process and system could help capture issues in a way that they could be reproduced. A well written issue report should read just like a good test case.
If there's a lack of staff, a tester should be able to review an issue and get enough details to reproduce it, so using QA to screen the issues for the developer might be a good idea.
Answer: In My Current Project, As Issue needs to be quickly handled it is assigned to Both Developer and QA. QA tries to replicate the issue while Developer tries to do thorough code check to ascertain it will work properly in the given scenario. Sometimes QA gets to the issue first while sometimes it is Developer that gets to the issue first.The process is different in different organisations and it also depends on the workload which is currently there on QA/Developer. At the end it is Team Effort to deliver Quality and nice user experience.
Answer: I think any bug reported by a user should first be shared with the QA team. This would give QA team a chance to work on the areas that were missed while producing test cases. Moreover, the QA team would be able to better analyze the situation to locate any flaws in the design and share them with the programmers.


Cross Yagi Antenna Design

Question: What will be the effect if I add the insulation between elements and metallic boom of the cross yagi antenna (where elements from outside of the boom, instead of through boom) and in this case boom correction is required?
If this is not the best way, feel free to suggest another methods for connecting the elements and metallic Boom.
Answer:
"But I want to get know what happen when the elements of the antenna are from outside and insulated from the metallic boom"

The characteristics of your antenna will change:

R component of Z at f will change
X component of Z at f will change
VSWR at f will change
Antenna Resonance f(r) (where X~~0) will change
directivity/gain-plots, -3dB angles, will change
front/back ratio will change

How much all this is changing is cannot be determined unless a lot of very precise detail is documented, and complex simulations are ran.
Even then these would be simulations, as the real numbers are actually dependent on the  mounting, height, and other environmental factors.
Answer: ANY time you change the mounting method the lengths need to be recalculated. You can google "element correction factor" and trust that their formula is correct or use an antenna simulator to do it for you. It is usually just a few percent (2%???) BUT IT WILL MAKE A DIFFERENCE!
Comment: Thank you. But I want to get know what happen when the elements of the antenna are from outside and insulated from the metallic boom.

Cross Yagi Antenna Design


Furnace keeps kicking off and on

Question: My furnace runs for a few min then flickers and shuts off and then the system recycles and it fires back up and the process repeats over and over and over etc....
Comment: Is the thermostat being satisfied, or is the furnace turning off before reaching the desired (set) temperature?
Comment: It sounds like possibly a dying flame sensor. What is the make and model of the unit? can you provide a better description of exactly what's happening?
Comment: This could be the diverter valve sticking.  The symptoms would be that the water is very hot but the radiators are cool.
Answer: I had a similar problem in which the furnace would start its pre-purge cycle, and then shut off.  The root cause was a broken solder joint on the controller circuit board, which I was able to see with strong reading glasses, and later repair by myself.
Try wiggling the low voltage electrical cables when your furnace acts up.  If you find an intermittent contact, it could be due to one or more broken solder joints.
Answer: That's what it's supposed to do.  It heats until a "high" cut-out temp, and rests until a "low" cut-in temp.  If it's colder outside, that will chill down your house much faster, it will hit the "cut-in" threshold much sooner, and cycle more often.  So if it started doing this during the cold snap, that's why.
If the heater is working at its limits due to the cold snap, it will barely turn off before it starts up again.  The fix is a bigger heater, or temporarily running additional heaters e.g. electric.
In some thermostats there is an adjustment for the "spread" between cut-in and cut-out.  You could try increasing that.
Also, thermostats are sometimes in a bad location: either too close to the heater, or blasted by a hot-air vent or convection.  They think the house has warmed up, so they cut out, which causes rapid cycling. That can be handled by moving furniture, closing or redirecting vents, putting a cover or shield around the thermostat (a piece of paper will suffice for experimentation) etc.

Furnace keeps kicking off and on


QM: why is reflection of a photon not a measurement?

Question: Many experiments with entangled photons are sending them through different glass fiber cables (e.g. in opposite directions for spatial separation). The photons will inevitably be reflected many times in the cable before reaching the end of the fiber, correct? Why is this interaction with the optical barrier layer not a measurment, which to my understanding would destroy the entanglement?
Comment: Position and spin are independent degrees of freedom. So some process equivalent to a measurement about position  does not destroy the spin entanglement.
Answer: The interaction is not a measurement because the probability that it will produce a measurable change in the momentum of the reflecting object is extremely small. The reflector is in a mixed state in which its momentum has a range of values that is large compared to the momentum of the photon. So the shift in the mirror's momentum as a result of the reflection will be so small that it will not be detectable with very high probability. I don't know the exact numbers but let's say it's -1,000,000 to +1,000,000 in units of the momentum the photon will impart upon reflection. The photon is incident on the mirror and changes its momentum by +1 so that the range is now -999,999 to +1,000,001. So the probability is large that if you measure its state you won't detect any difference.
Comment: I was under the impression that "measuring" is the pure act of interaction with other particles, no matter if there is some mind or apparature behind this which would assesses the quality of interaction.
Comment: The issue is not whether there is a mind it is just whether there is a record. You can have a record of something without anybody seeing it. Fossils were records of animals long before anybody dug them up. In the case of the mirror the issue is just whether the photon reflecting from the mirror generates a record and it doesn't with high probability.


Exceptions to Intrasyllabic Synharmony in modern Czech?

Question: Studying Czech (and reading about the history of slavic languages) I encountered the concept of Intrasyllabic Synharmony, which somehow motivates the Slavic Palatalizations by explaining that the velar consonants "adapted" their point of articulation when combined with front vowels. Chains such as

*k > *kʲ > *č,
*g > *gʲ > *dž > *ž,

(First Palatalization)
*k > *t > c, and
*g > *d > dz > z

(Second Palatalization)
are then nicely explained in *e/ē, *i/ī environments (and the diphthongs thay yield them).
Interestingly, this racionalization helped me to see some logic behind inflections that before seemed random or highly irregular (to name an example, klika --> klice). However I am now curious to understand why then in some Czech words there are velar consonants next to front vowels. I am not thinking about obvious loanwords, but about basic words that -I guess- must be very old, such as taký/také. Does this not violate Intrasyllabic Synharmony? Is this an instance of irregularity in the Sound Laws, or is there something deeper at play here?
Comment: Just noting, "taký" and "taká" are just in some dialects, not in the contemporary standard Czech. This also partially applies to "také", but it depends – if it is just neutral gender of taký/taká (meaning "such"), it is dialectical. If it means "also", it belongs to contemporary standard Czech.
Answer: The so-called "Sound Law" and the thing that was regular is 1500 or more years old, when it was a general rule of articulation in the proto-language. It was a subconscious, unavoidable "law" in the same way that aspiration is in most dialects of English. It did not produce č, it produced fronted kʲ. Subsequently, this process was phonologized – became a rule of the "morphophonemics", and gave rule to underlying segments like /č/. This is similar to how the English phonemes [v,z,ð] arose from earlier *f,s,θ by inter-vocalic voicing – then other factors made it impossible to predict which fricatives would voice, and children had to simply learn that some words have [v] and some have [f].
The Czech vowel written "y" derives from a much earlier central or back vowel, which has widely become fronted in Slavic. In Czech, the vowel itself is not pronounced differently from "i", but it has a different effect on the preceding consonant, so that synchronically there are two kinds of [i] (similar to the two kinds of [o] in Spanish, one which diphthongizes when stressed and one which does not).
The original "sound law" as principle of articulation is long done with, and what Czech has inherited is the consequences of that law, namely a system of grammatical rules. That is, there is no longer "Intersyllabic harmony" in Czech, there is the grammaticalized residue of such a phonetic law.
Comment: That's clarifying, thank you. I feel silly to ask this, given that spanish is my native language, but, could you clarify that thing about "the two [o]"? Maybe with an example? I guess it is something I do without realizing it :D  (It was not that long ago that I learnt that I've been saying all my life [deðo] and not [dedo] :S )
Comment: contar / cuento, montar /monto.
Comment: I must be missing something, those [o] sound exactly the same to me. I need to look into that more carefully. Is the [o] in *contar* different than the one in *cuento*? Also, the only diphthong there is the *ue* in *cuento*, which does not have [o]. And the only stressed [o] is the first one in *monto*. So I don't really get the meaning of the comment about the diphthongs and the stress, sorry.
Comment: The sound exactly the same but they behave differently. Sometimes [o] diphthongizes when stressed, sometimes it doesn't. Same with palatalization and [i] in Czech.


Vimperator Style Extension for Safari 5?

Question: Do we have a Vimperator style extension for Safari 5?
Answer: Not really. I've been hoping for a good one, but I keep coming back to Firefox and Pentadactyl, a Vimperator fork.
Safari does have Vimlike and Vim Keybindings, but Vimperator and Pentadactyl are miles ahead in terms of features. If all you're looking for is Vim-style movement and the ability to follow links from the keyboard, those should do the trick, but I miss a lot of the deeper features that Pentadactyl offers: javascript evaluation, quicklinks, ability to yank links from the keyboard, and much, much more.
Answer: Vimari also offers some of the keyboard shortcuts from Pentadactyl.
Answer: An old question, but it seems that the plugin sVim does a decent job now.
Answer: I found the extensions by Daniel Bergey useful: http://dbergey.github.com/
Answer: Have a Look at: https://github.com/flipxfx/sVim
It's similar to cVim for Chrome.


Wind measure with strain gauge

Question: I'm trying to build my own weatherstation for my home, I want to measure temperature humidity and wind strenght and direction. For the wind I have a question. I want to measure the wind with a ball on top of a stick (schematic), and measure the bending of the stick with some strain gauges. Is this possible or just a crappy idea. And what material would I need for the stick that it bends for low wind forces too?
Comment: This won't work.  Vortex shedding forces will swamp the average force (from Re  = 6 × 10^3 to Re = 3 × 10^5 . Build an anemometer.
Comment: Calibrating that would be a nightmare.
Comment: @PhilSweet Would those forces still be such an issue for wind across a flat plate?
Answer: There may be other designs from which you can select, but I would consider a mechanism that does not depend on a specific material bending, especially at low air speeds.
I suggest this, because a light, easily bent material may snap at higher velocities, while a stronger one may exhibit insufficient bending at lower speeds.
Consider a design in which a material of sufficient strength, perhaps aluminum has a hole drilled through it. This plate can be of any outer shape but should have a thickness to allow pressure sensors to be attached to the inside surface of the hole.
Instead of a plate, one could use a strong piece of thick walled aluminum tubing of a length that would support these pressure sensors. Placed at eight equally spaced locations on the inside wall of the tube, they would provide pressure information to your device, which I envision is something like an Arduino or Raspberry Pi.
This pressure sensing tube would be placed as near as possible to your sphere, while the sphere is mounted on another piece of lightweight tubing nearly the same diameter as the sensing tube.
The opposite end of the sphere tube should be some distance away to reduce the angle of contact between the two tubes. Consider it as a lever. Long levers have small angle changes compared to short levers. The best circumstances should arise if the inner tube is a fraction of a millimeter smaller than the diameter of the sensors within the outer tube. This reduces point contact on the sensors, reducing the possibility of damage.

By having many sensors inside the tube, you can do more accurate direction locating and pressure measurement. If your sensors are not strips but are instead short button types, the surrounding tube can be shorter, of course, but should still remain as tightly around the sphere tube as possible.
Comment: Heck, why not just build a pitot tube?  No reason to reinvent anything.
Answer: Here's another approach:
While just a bit over the top, using something like this with somewhat lower density materials may be effective.  Doesn't turn in to electronic measurements readily.
I have seen simple wind guages that had a flap pivoted on one edge, and the angle from vertical was calibrated with wind speed.

A comment above is certainly correct:  A round pole will shed vortices and will require some post measurement tricks to get a reasonable number out of it.
You might be able to derive wind speed from the oscillations set up by the vortex shedding.  Another method that is fraught with calibration issues.
You also may find that at certain wind speeds you get resonances that turn your flexible pole into so much debris, or give wild answers.

If your goal is to make a wind measuring device  without moving parts, you might be able to rig something with timing ultrasonic pulses on a round trip cross wind and up/down wind.  I bet you could get within a few percent with two sets at 45 degrees to each other.
Answer: I like the idea above, however I also like the idea of a bending poll. It could work. You'll need to pump electricity into the poll and measure resistance. Essentially, as the poll bends, resistance would increase. Setting the limits might be a bear. Never tried something like this, but you could theoretically gather the information needed. At 0 mph u see 0 deflection, with Cu possibly, u see 0 resistance. At 300mph the rod is at 90 degree, and you see resistance at half. Just an estimate of course, again this is theory. Could work however.

Wind measure with strain gauge


Starting an app when the screen is locked?

Question: Is there any easy way to start an app when you press the button to lock your screen? I've seen custom lock screens before so I know it's possible even if I have to make my own app for it. I have an app that I want to pop up every time the screen is unlocked, but it doesn't do it on it's own. I've seen/used other apps that could do this so if necessary I would code my own app to do this, but I'd prefer an already existing, preferably free option.
Answer: There might be multiple solutions to this. One I can think of involves the use of Tasker, the most flexible automation tool for Android. You could create a profile that triggers on "Screen Unlock", and have it start an app.
However: though there's a free 7 day trial available on the projects homepage, after that the app costs about 5 Euro. There are many other automation apps available on the playstore which might be able to achieve the same. As a long-time Tasker user I no longer try the others, so I cannot tell for sure.
Condition: Event → Display → Display Unlocked
Task: App → Load App → (select your app here)
Comment: Thanks for that. I ended up getting AutomateIt because it's free and works just as good for my purposes. If you hadn't mentioned tasker I might never have found AutomateIt :D
Comment: Glad it helped! There are a lot of automation apps out there, hard to keep all their features and limitations in mind. Luckily there's almost always one fitting the purposes of the questioner :)


What is the opposite of the word 'optimum' for this context?

Question:
The use of the optimum formula of x compounds is relatively small.

What is the opposite of the word optimum? Is it non-optimum? Could inefficient be a choice?
Comment: *Optimum* is generally equivalent to "best" or "best fit", but not necessarily "most efficient" - there's other ways of being the best (e.g. "optimum strength").  You would need to say *optimally efficient* for *inefficient* to really be the opposite.
Answer: It depends on what you mean by opposite:

Do you mean exact opposite, as the hottest one -- the coldest one?
Or do you mean just negation, like the hottest one -- not the hottest one?

For exact opposite
I can't find antonym for the adjective optimum/optimal here.
Although antonym for the noun optimum is the noun pessimum, the word pessimum neither can be used as adjective, nor has correspondent adjective in English (and you certainly need an adjective here).
For negation
The synonym for non-optimal is suboptimal.

The use of the optimum formula of x compounds is relatively small.
  On the contrary, suboptimal formulas/suboptimal formulae are widely used.

Post scriptum
I recommend you changing the word optimum to optimal here, as you certainly need an adjective (although the word optimum can be used as adjective too, most people prefer to interpret it as noun). And together with some other changes:

The use of the optimal formula for x compounds is relatively rare.
  On the contrary, suboptimal formulas/formulae for x compounds are widely used.

(If I understood your original sentence correctly.)
Answer: There's something wrong with your sample sentence. I know because I have no idea what it means.
Apart from that, I prefer "optimal," which is a natural adjective, to "optimum," which is not.
That said, there is no exact antonym for "optimal." But, since it means "the best possible under the circumstances," you might as well make do with "worst possible," "least efficient," or simply "horrid."
Answer: From the Latin, pessimum, but that word didn't actually make it into English. Instead there's optimism and pessimism, but those are entirely different.
Because the word didn't cross languages with its native opposite, though, it doesn't have a clear one in English. Ricky has some decent ones.
Answer: 'optimum' is not a native English word. 'optimal' would be one. As such, its antonym will be 'non-optimal'(used frequently in mathematics).
'optimum' is an example of mixed English, which is usually spoken by non-native speakers. I, being an Indian, have seen examples of this among locals.


How to use "get late"?

Question: I know the meaning and usage of "get late" in "It's getting late, I've got to go"
Now I am wondering if it is correct to use the phrase "get late" in this sentence: "Sorry I got late for school today" or rather "Sorry I got late to school today" or "Sorry I arrived late at school today".Which is correct?
In the same way, is it correct to use it like this: "He is running because he is afraid of getting late for school on the first day (of school)"
Thanks you all.
Answer: Sentence: "It's getting late, I've got to go"
That's idiomatic, yes. The entire phrase refers to time: it's getting late.
The it is called a dummy pronoun and refers to a time. Dummy pronouns are used a lot in English: "It's odd that you think my letter is good."
However, a person is late. A person does not "get late". A person can get other things though: get rich, get poor, get tired. In this usage the verb get means become.
I am late for school. It got late. [it=time expressed with dummy pronoun].
Comment: You seem to have opposite takes on a person getting late. Could you tell me more on this?
Comment: I mean you two!
Answer: You can get to school late.
And when you're running late, you're afraid of being late for school or of getting to school late.
Notice the different placement of the word late.
We don't say get late to school. not idiomatic Rather, you get to school late.
But you can "get late for school" as the result of some delay.
Comment: You seem to have opposite takes on a person getting late. Could you tell me more on this?
Comment: I mean you two!
Comment: That's because of his last line. He means: It can get late for school. Meaning: It's too late to go to school. So, there is no disagreement. "It's getting late for that."
Comment: Or "late for school" is your state. You  can become late for school if you experience a delay.  There is a roadblock because of an accident, and you can say "Now I am late for school" because "I got delayed". That is not the same as arriving late: *I will get to school late*.

How to use "get late"?