Ever since my accidental ‘discovery’ of the word CEILIDH written on a numb3rs blackboard, I keep an eye on their blackboards whenever I watch a new episode, and try to detect terms I might know. Here’s todays screen-shot

I had to choose one frame from a minute long shot (the ‘link’ on the left hand side is more recognizable in other frames). Anyway, here’s what I thought to recognize : a link, a quaternion-algebra over a number field,

to be precise, and a in it. So did someone construct link-invariants from maximal orders in quaternion algebras? I surely didn’t know, but when in doubt there is always… google. I searched for ‘link invariant quaternion algebra maximal order’ and the third hit on page 2 gave me a pdf-file of a paper which seemed to have the relevant terms in it.

The paper is Automorphic forms and rational homology 3–spheres by Frank Calegari and Nathan Dunfield. Bingo! Their first figure is the ‘link’ drawn on the blackboard

which actually turns out to be a graph… This couldn’t be a coincidence, so as in the ceilidh-story, there had to be a connection with one of the authors. ‘Calegari+numb3rs’ didnt look promising but ‘Dunfield+numb3rs’ returned the hit Crime and Computation from CalTech News.

Krumholtz’s star turn as a math genius belies his dismal record as an algebra student. He explained that in preparation for his role he hung around Caltech last fall, “wandering the hallways and campus for two to three weeks,” to soak up the academic ambiance. To plumb character motivation he talked to a real-life youthful math guy, Caltech’s 30-year-old professor Dunfield.
In a phone interview shortly after the show’s television debut Dunfield recalled spending about an hour with Krumholtz, who plays 29-year-old Charlie. “He wanted to know what it’s like to do mathematics and work in academia, what types of things his character would likely be concerned about, like tenure or other issues.”
The professor, who was so un-starstruck that he hadn’t even made a point of watching the premiere, added, “He wanted to know, why would somebody choose to become a mathematics professor. Would they have to love math?” What was his response? The professor said he does not recall.

Google analytics is collecting data on this site for over a month now. Perhaps it is time to share a few lessons Ive learned over this period.

UPDATE : I have de-activated all google analytics plugins on this site. I may re-activate them for short periods later but ONLY to detect problems or to check on plugin performance. I will announce this in the sidebar with a ‘this site contains google analytics script code’-sticker. I encourage people using google analytics stalking code to do the same.

1. Aim at the generic visitor, not the specific

Analytics offers an amazing amount of data, in debatable detail. For example, via the map-overlay one can zoom in to specific towns and communities. When combined with other data, such as new/returning visitors etc., this quickly becomes borderline stalking. So, repress that urge to check-out whether someone you know is reading your blog, and how often, and how long, and how deep, and … Use analytics only to get an idea of what the generic visitor does with your site.

2. There is a world outside your blog

Don’t get obsessed by analytics-data and, certainly, do not feel that you have to react to it, all the time! For example, below the evolution of the number of visitors coming here over the last month

The dramatic fall in attendance from last friday until this monday might have worried me (when obsessed). However, a quick check gave a similar drop for the number of new visitors and the number of search-engine referrals. Probably, people were, at that time, more interested in the stock-market-crisis than in this blog… Besides, most people visiting here come from the US and I learned that they had a Luther King vacation day, so perhaps lots of them enjoyed a prolonged week-end, away from their computer.

3. Detect & correct major, lasting changes

So, forget about temporary blips. However, when a certain trend has every indication of becoming permanent, it might be the moment to check out what is going on. Below the bounce rate-evolution over the last month

This is what you might call a lasting drop! Fortunately this time I knew what was going on, because of the actions described in the bounce rate post. But, when you detect a similar drop in certain stats it is time to figure out the causes. Perhaps you de-activated by mistake a certain plugin (see below), or something is wrong with your server, or…

4. Check-out plugin performance

There are tons of Wordpress plugins, some useful, some less. So it is best to check whether activating a plugin has the desired effect. For example, you should be able to detect installation of an SEO-plugin (for, Search Engine Optimalization) in the Traffic Sources/Search Engines graph, installing and using a tagging-plugin should give you more referrals from Technorati and look-a-likes, etc.

5. Don’t take it too seriously

You can use analytics data just for fun! For example, do a quiz, show visitor-data and ask for global events explaining the graph (as above). Or notice quirks in your data. For example, here the time-on-site graph over the last month

My generic visitor seems to have a cyclic attention-span…

The next thing on my tech-to-do-list : learn all about Yahoo Pipes :

Pipes is a powerful composition tool to aggregate, manipulate, and mashup content from around the web. Like Unix pipes, simple commands can be combined together to create output that meets your needs. Here are a few popular ways the service can be used:
- create your ultimate custom feed by combining many feeds into one, then sorting, filtering and translating them.
- geocode your favorite feeds and browse the items on an interactive map.
- remix your favorite data sources and use the Pipe to power a new application.
- build custom vertical search pages that are impossible with ordinary search engines.
- power widgets/badges on your web site.
- consume the output of any Pipe in RSS, JSON, KML, and other formats.

I’ve posted before on setting up your own lifestream, or your own planet, or scraping feeds, or subscribing to my brain, or … whatever. The good news is : all these ideas are now superseded by Pipes!

Pipes is a free online service that lets you remix popular feed types and create data mashups using a visual editor. You can use Pipes to run your own web projects, or publish and share your own web services without ever having to write a line of code. You make a Pipe by dragging pre-configured modules onto a canvas and wiring them together in the Pipes Editor. Once you’ve built a Pipe, you’ll be able save it on our server and then call it like you would any other feed. Pipes offers output in RSS 2.0, RSS 1.0 (RDF), JSON and Atom formats for maximum flexibility. You can also choose to publish your Pipe and share it with the world, allowing other users to clone it, add their own improvements, or use it as a subcomponent in their own creations.

This is the essential message to get : yahoo-pipes allows you to remix the web, filtering out all noise! And the good news is

1. There are plenty of public pipes around to get you going, and
2. Pipes has an iTouch-friendly interface (see above left). All you have to do is to Safari to iphone.pipes.yahoo.com and use them.

Here are a few public-pipes you can use out of the box!

• iPhone / iPod Touch: The Most Comprehensive Feed Ever!, doing what it promises : giving you the best iTouch-posts without having to roam for them.
• JSON Geocoder, returning lat/lon/address info from the the given address.
• Uber Blog Search, Search all the blogosphere with one query. Hits Google, Ask, Technorati, and icerocket then returns the unique results. Below the web-interface giving the results for ‘noncommutative’…

• Meta Search Alerts if you want a less ‘neverendingbooks’-based reply

and finally, one of my favorites, implementing to some extend the Lifestream-idea (iTouch-interface above left)

• lifefeed - virable, Easily Aggregate your social whereabouts great for blogs profiles and more! Aggregates Your Feeds From: -Digg -Last.fm -Twitter -Flickr -Del.icio.us and your very own blog Adopt and Improve, enjoy!

I’ll promise to spend some time soon to set up my very own pipes and make them available…

I couldn’t believe my eyes. I was watching an episode of numb3rs, ‘undercurrents’ to be precise, and there it was, circled in the middle of the blackboard, CEILIDH, together with some of the key-exchange maps around it…

Only, the plot doesn’t involve any tori-crypto… okay, there is an I-Ching-coded-tattoo which turns out to be a telephone number, but that’s all. Still, this couldn’t just be a coincidence. Googling for ‘ ceilidh+numbers‘ gives as top hit the pdf-file of an article Alice in NUMB3Rland written by … Alice Silverberg (of the Rubin-Silverberg paper starting tori-cryptography). Alice turns out to be one of the unpaid consultants to the series. The 2-page article gives some insight into how ’some math’ gets into the script

Typically, Andy emails a draft of the script to the consultants. The FBI plot is already in place, and the writers want mathematics to go with it. The placeholder “math” in the draft is often nonsense or jargon; the sort of things people with no mathematical background might find by Googling, and think was real math. Since there’s often no mathematics that makes sense in those parts of the script, the best the consultants can do is replace jargon that makes us cringe a lot with jargon that makes us cringe a little.
From then on, it’s the Telephone Game. The consultants email Andy our suggestions (”replace ‘our discrete universes’ with ‘our disjoint universes’”; “replace the nonsensical ‘we’ve tried everything -a full frequency analysis, a Vignere deconstruction- we even checked for a Lucas sequence’ with the slightly less nonsensical ‘It’s much too short to try any cryptanalysis on. If it were longer we could try frequency analyses, or try to guess what kind of cryptosystem it is and use a specialized technique. For example, if it were a long enough Vigenere cipher we could try a Kasiski test or an index-of-coincidence analysis’). Andy chooses about a quarter of my sugges- tions and forwards his interpretation of them to the writers and producers. The script gets changed, and then the actors ad lib something completely dif- ferent (’disjointed universes’: cute, but loses the mathematical allusion; ‘Kasiski exam’ : I didn’t mean that kind of ‘test’).

She ends her article with :

I have mixed feelings about NUMB3RS. I still have concerns about the violence, the depiction of women, and the pretense that the math is accurate. However, if NUMB3RS could interest people in the power of mathematics enough for society to greater value and support mathematics teaching, learning, and research, and motivate more students to learnthat would be a positive step.

Further, there is a whole blog dedicated to some of the maths featuring in NUMB3RS, the numb3rs blog. And it was the first time I had to take a screenshot of a DVD, something usually off limits to the grab.app, but there is a simple hack to do it…

The bounce rate indicates how many web-visitors leave the site without visiting any other pages before a certain session timeout elapses. That is :

High bounce rate means the site must be horrible to site visitors and most likely they would never return again. They are not even interested to check other content of the site. First impression counts.

After installing google analytics some weeks ago, I noticed a worrying high bounce rate : close to 80%… At first I thought this was due to the fact that all iTouch fans left the moment they saw a mathematical symbol, but further analysis proved me wrong : iTouch fans study posts here a lot longer than the average mathematician. But then, what was the reason? Is this site really so horrible to look at? is the content of such poor quality?

Anyway, I’ve tried out a couple of tricks, with surprising effect. The bounce rate dropped from 80% to under 3% and best of all, it appears to stay that low. Here, the google-analytics bounce-rate evolution of the last 3 weeks

So, what kind of magic voodoo did I perform on january 6th? I’ve installed a couple of Wordpress Plugins and changed the upper part of the entry-page. My basic assumption is that people leave a site when they come to it for specific information (for example via a search engine), do not find the info immediately and don’t want to spend too much time looking for it. So, I wanted to have all tools to find content on this site right in front of the potential new-comer. Here are the 5 major changes to the header part and the plugins Ive used.

1 : Rather than having a monthly-archive in the sidebar providing no more info than the number of posts in a particular month, create a proper archive page where visitors can find the titles and links to all posts in reverse chronological ordering. I did use the Smart Archives Plugin.

2 : Even better : have a drop-down archive right under the header-picture so that visitors can scroll down the list of all posts without having to load another page. Ive used the Awsom Archive Plugin.

3 : Let visitors see in a glance what your blog is all about by having a tag cloud under the header. I didnt feel like tagging 300 old posts, so I used the Simple Tags Plugin to do it all for me.

4 : Have a welcome message near the top to aid new visitors (especially when you have, like me, 77.51% of them around). The message disappears after their third visit. It’s a wonderful idea, made possible by the What Would Seth Godin Do-Plugin.

5 : Write series of posts and have links to the other parts available at the top of the new post. Likely, people are going to check out the other parts for more information. Rather than hard-coding the links by hand, Ive used the In Series Plugin.