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# Category Archives: Community

## A long step towards the adult PhysicsOverflow

Today, the new category system, which allows an unrestricted number of category-levels, has been installed on PhysicsOverflow. This system was required to enable the categorization of submissions beyond the four levels provided by the actual Question2Answer (Q2A) framework. This new system is almost invisible for the user, but has the important function to make a (future) large number of submissions searchable by the user. About two and a half months have been required to develop this system, you had to wait for a long time. Therefore I like to give you some insights.

The original category system of the Q2A framework is a hierarchical database model. Every node (a category) is linked to its parent by the ID of the parent node. Such a model enables a fast writing of new nodes (you just create the node and link it to its parent), while queries through the tree are usually slow. Q2A solved this issue by a fixed number of 4 category levels. To be able to find parents in a short time, the path to the parent is hard-coded in every post. This means that every post contains four indices storing the way back through the tree. This is a clever and fast solution. However, it can not be extended to an unrestricted number of categories, it even gets slow if extended to 8 levels for instance. The category system is written in the core code of Q2A and spread over a large part of the system.

Another issue arising when we increase the number of category levels is the user interface. Actually, when the user asks a question, he has to select the category for this post. The user interface uses select tags like:

It is clear that for instance for eight categories, the place on the page is too small to display all these tags side by side. Therefore also the user interface had to be changed. The new user interface take much less room and looks like this:

For the new category system, I have implemented another database model, called nested set model. It allows for an unrestricted number of category levels. While queries through the categories become very fast, the insertion of nodes is slow, because all indices of the whole tree have to be changed. However, changes on the categories will be used much less frequent than for instance to display the tree. Like this, it is well adapted to our needs.

As already mentioned, the original category system is placed in the core code of Q2A and is active in almost all pages provided by the framework (even in pages I never expected this). I had to replace 9 files completely, all select specifications for database accesses to the category system had to be renewed and, naturally, the code for the nested set model had to be written. To give you an impression on the size of the task, here some numbers: The original Question2Answer framework consists of about 36’000 lines of code. Until today, I have written 18’100 new lines of code for PhysicsOverflow in form of plugins, layers, overrides and changes in the core code, about half of the size of the system. The new system required 5’800 additional lines of code, which explains, why it took that long to realize it. I hope now that I was able to test all use-cases so that there remain eventually only minor bugs.

The next development step will be a surprise, stay tuned!

polarkernel

## We have a talk at the 5th Offtopicarium :-) !

A few weeks ago, Piotr Migdal made me aware of the Offtopicarium (he is among the organizers), which is a mixture of scientific conference, workshop, and geek gathering ;-). Its purpose is to discuss topics and ideas, which are usually off-topic  to “regular” events and meetings, but nevertheless interesting and exciting.  The Offtopicarium welcomes (rather geeky 😉 …) people, who have a good idea and are passionate about it, such as scientists, entrepreneurs, people involved in startups, NGOs, and such.

So, after nice discussions and kind encouragement by Piotr Migdal, I finally submitted an abstract. It got just accepted, such that we will have  a (20 min + 20 min discussion)  talk  about PhysicsOverflow at the

## 5th Offtopicarium (26-28.09.2014, Węgierska Górka, Poland)

Of course, I will shamelessly use this opportunity to introduce and advertise PhysicsOverflow:

The Q&A part as a revival of  Theoretical Physics SE and a physics analogue of MathOverflow, whereas the Reviews section should take the role of an overdue competitor of the (outdated and flawed in many ways) journal peer-reviewing process.

And who knows, maybe we will also find a second system developer there, to help and unburden Polarkernel …?

Anyway, summer holidays are mostly over (at least in Germany …) and members of PhysicsOverflow are heartily encouraged to make PhysicsOverflow look as awesome  as possible by nice contributions 😉 !

Even though I already have some ideas of course ;-), I would be happy to consider suggestions concerning the talk, they can be mentioned for example in the comments here.

Cheers !

## A “beginners” complementation to PhysicsOverflow?

PhysicsOverflow has always been, and will always be a site for physics and has always maintained, and will continue to forever maintain a minimum level or standard for questions. Specifically, every question posted on PhysicsOverflow must be at least at a graduate level. For example, in terms of theoretical physics, quantum field theory and advanced general relativity mark the bottom level for questions.

However, we have recently had private discussions with a user who has preferred to remain anonymous, about setting up a lower-level completion to PhysicsOverflow. I personally consider this to be an absolutely brilliant idea. When we first talked about starting a new physics forum or Question & Answer site, we immediately wanted to have a site at a higher level because we felt that a free, frank, and non-censorious environment was most needed for a site at a higher level as opposed to a site for basic physics. When we conducted our poll for the level of our site nearly last year, “graduate level” won the poll. However, now that PhysicsOverflow is up and running, we realise that every community that discusses a scientific discipline needs a free, frank, and non-censorious environment to develop.

First of all, let me note that we are NOT planning to allow lower-level physics on PhysicsOverflow. PhysicsOverflow shall maintain its level forever. Our plan is to set up an additional site at a lower level than PhysicsOverflow at a domain like beginners.physicsoverflow.org. They will get to use our software (since our software contains many additional plugins made by polarkernel to the freely available, open-source Question2Answer software). This was not the first time we have seen the lack of a free, frank, and non-censorious site for lower-level physics. Another user, whose preference for anonymity is unknown, has also previously expressed that there is no undergraduate-level counterpart for PhysicsOverflow. The plan is therefore to set up an additional site (PhysicsUnderflow?) at a subdomain of PhysicsOverflow, like beginners.physicsoverflow.org or underflow.physicsoverflow.org.

## Will this positively affect PhysicsOverflow?

Yes, of course!

• Post migration – This is the main positive impact of a “PhysicsUnderflow” on PhysicsOverflow. If a question is too basic for PhysicsOverflow or too advanced for “PhysicsUnderflow”, the question can be migrated between the sites. There is a Question2Answer plugin for this.
• More contributors – I mean positive contributors. If someone enjoys participating on “PhysicsUnderflow”, they have a greater likelihood of participating on PhysicsOverflow, when they’re ready to participate on PhysicsOverflow.
• Post diversion – Currently, we tell new users in their confirmation emails that PhysicsOverflow is a site for physics at a graduate-level and above; basic questions go here: physics.stackexchange.com. If we have a brother site, “PhysicsUnderflow”, we can tell users to participate on PhysicsUnderflow for lower-level physics.

## How can I help?

The PhysicsOverflow team is unfortunately uncapable of providing our full attention to “PhysicsUnderflow”, since we all have long to-do lists for PhysicsOverflow itself. The “PhysicsUnderflow” project requires:

• At least one Super-administrator. This is essential. A super-administrator’s tasks include: executing the will of the community and managing the site in general, importing of posts from StackExchange, if the PhysicsUnderflow deems this necessary.
• It would be nice to have a Developer to assist polarkernel at least in the beginning for setting up this site. This developer would have to voluntarily support the development of a “PhysicsUnderflow”, i.e. to put it straightforwardly, we, as a very small team, are currently incapable of paying an additional developer for the development of a “PhysicsUnderflow”.
• Most importantly, the site needs to have a Community. There are no minimum criteria for activity (unlike in some dystopic settings across the internet), but people who are interested in a “PhysicsUnderflow”.

If you want to make the idea of a “PhysicsUnderflow” a reality, then please try to help out.

## I am willing to be a super-administrator on “PhysicsUnderflow”! What next?

The first step in setting up a “PhysicsUnderflow”, in my opinion, is to set up a public blog for organised disucssion on this matter, like how PhysicsOverflow set up this very blog as per John McVirgo’s suggestion. You are encouraged to use as structure similar to that of this blog when writing posts for comment discussion on this blog of a “PhysicsUnderflow”. So please tell us if you are willing (and have the time, capacity, and inclination) to be a super-administrator, and tell us the URL of the blog that you have set up so we can link to it from the top of this post.

## How will PhysicsOverflow support PhysicsUnderflow?

• Helping you install all the PhysicsOverflow software (including the Question2Answer core, all our plugins, our theme, admin panel code, and everything) on it.
• Providing you with a list of our custom pages.
• Telling you how we deal with community moderation, provide a list of our community moderation posts.
• Advising you on managing a “PhysicsUnderflow”, etc., ; for example, do you think it that this beginners site would also need to import posts from SE? In that case, it would be a pretty huge burden on you, since there are a lot of basic questions on SE. Maybe you should just import questions with at least 10 votes and not graduate-level+.
• Promote the beginners site on the tpproposal blog and on the meta of PhysicsOverflow (done)

Eventually, I hope to see more and more “*erflow” (where “*” could be “und” or “ov”) sites form, and eventually form some sort of a large “Erflow” network with each scientific discipline having two sites, one overflow, and one underflow. Like a chemistryoverflow.org, etc. Anyway, that will probably take years : )

## We Have Liftoff!

Liftoff

PhysicsOverflow public beta is online now since 17 days. After a turbulent start with some database issues on our host and spam attacks, now the site is stable and working fine. After an ongoing and continuous improvement of details, the section with Q&A on physics takes now the main part of activity on the site. Since we have gone online at 4th April, more than 150 new users have registered on the site and many of them are already quite active. The number of visits per day exceeded the number of visits on Theoretic Physics on SE since the first day, as can be seen in the following graphics:

This is great, since we aren’t even part of a huge network! Our questions per day is about 5.6 (excluding imported posts), which is a lot more than TP.SEs. However, as already stated, the site does not depend on these figures, there is no deadline, as it was on TP. Also the term beta does not mean that the site will go away, it means only that we have still much more ideas to obtain the full-fledged version of PhysicsOverflow.

Now is the time where the site gets shaped. If you participate now with your votes, ideas, opinions, questions and answers, you contribute to build a site with contours as you like them. Don’t stay outside, have a look at PhysicsOverflow, register there if you like it, or contribute here on this blog.

Review Section

We are still a small team. However, we are working with full power to be able to leave the beta state and to complete the site, as intended. The main part for this will be the Review Section, as already announced in this blog. This is not only a reconfiguration of the site, it requires a considerable part of new development, because such a feature is not foreseen in the Question2Answer framework. In detail, the following main functionalities have to be developed:

• Integration of new pages, called Submission and Review.
• Two voting criterias, one for originality and one for accuracy.
• New page design, enabling display of a score value from the votings.
• Redesign of voting mechanism, distributing votes to multiple authors.
• Integration in the rep update and recount system.
• Adding and managing the required database tables.
• Increasing the category depth to realize hierarchical tagging system.
• Integration of score as new sorting criterion.
• Software for mass import from ArXiV.
• Software for daily import from ArXiV.

We are on the way with all that and look forward to realize these steps within a reasonable time. Stay tuned!

## Physics Overflow is going to go public!

Finally, a long-awaited announcement. Physics Overflow’s private beta will end next week at midnight on Thursday, i.e. at 0000 hours, 4 April 2014!

This means that the public beta, which is the fifth phase in the history of Physics Overflow is going to begin. The phases so far are:

• The blog
• The offline site [Foetushood]
• The private beta [Infanthood]
• The public beta (will begin next week) [Childhood]

So Physics Overflow will reach it’s childhood at the age of one and a half months next week! Sorry, couldn’t resist from giving stupid analogies.

Seriously, these things remain to be done, with the deadline (I copy an answer of mine from Physics Overflow):

I think that the TP.SE question Public beta: Attracting users? is also relevant to us.

In my opinion, there are some plug-ins (a job for polarkernel) remaining to be installed as soon as possible, such as

These plug-ins are good to have, and the first one is almost a necessity. I wonder why Q2A does not incorporate it in it’s core.

The second one gives admins some great tools to see how well the site is faring at a glance. It could even be made public I hope.

Additionally, we also may want to decide on solutions for having a chat room. That somehow reminds me; we may also consider retaining the tpproposal blog as a (hopefully $\infty$) life-long blog for Physics Overflow. The chat room; I’m not sure if we should wait for the public beta to start or not, but I just thought of reminding everyone about it.

From the things you have listed the following need to be done by 0000 hours, [CEST]

• Sunday:
• Tuesday:
• We should invite everyone listed in the blog post.
• We should announce on the TRF thread and invite Lubos too. Dilaton will write a guest post on TRF.
• We should obviously announce on the blog.
• On the blog, user10001 (dushya) had the idea of promoting the site to various physicists in the world.
• Wednesday:
• I (and anyone else who is interested) need to finish 14 and 15 of the FAQ.
• The long users need to be corrected (I will do this).
• The main page needs to be set to Q&A.
• Thursday:
• Change permissions
• Edit robots.txt (a job for polarkernel)