## December 31, 2009

### Haiku

As part of his science fair project, my 3rd-grader needed a large number of random strings of 8 digits, in each of which “1” appears four times, and “2”–“5” appear once each.

Posted by distler at 10:55 AM | Permalink | Followups (5)

## December 28, 2009

### Instiki 0.18

I just released Instiki 0.18.

It’s been half a year, since I announced the release of 0.17 and there’s lots of new stuff. So I guess it’s time for an upgrade

New feature include:

• Syntax colouring for code blocks: ‘html’, ‘xml’, ‘ruby’, ‘ansic’, ‘javascript’, ‘sqlite’, ‘yaml’ and ‘css’ modes.
• Source view [suggested by Andrew Stacey]
• Auto-resizing Textareas scale to fit viewing area.
• Passenger support (including X-Sendfile support, if the Apache mod_xsendfile module is installed).
• Upgraded to Rails 2.3.5 and Rack 1.1.
• Now runs on Ruby 1.9. (If you’re a Passenger user, you may need to upgrade to Passenger 2.2.8, which works around some bugs in Ruby 1.9.1.)
• Upgraded for itex2MML 1.3.19 (which works under Ruby 1.9, and has several new features, relative to 1.3.15).

#### Update (1/7/2010):

Because of some character encoding issues under Ruby 1.9 (mostly affecting My SQL users), I decided to issue a quick update to Instiki 0.18.1. [Thanks to Andrew Stacey for running these issues down.] I also added some new features: (Markdown-Extra-style) fenced code-blocks and ‘fortran’ syntax colouring. [Both courtesy of Jason Blevins.]

 rake upgrade_instiki


before running the new version.

## December 21, 2009

### GraviGUT

One of the disadvantages of having waded into the Lisi affair is that I keep getting asked about related ill-conceived ideas for “theories of everything.” For the most-part, such ideas don’t have a relentless publicity machine behind them. Nor do they receive what can only be described as a credulous reception in certain corners of the Mathematics community. But still, it is assumed that one has an opinion about them.

One such idea is the $Spin(3,11)$ “GraviGUT” of Nesti and Percacci. The bosonic fields consist of a connection for a noncompact $Spin(3,11)$ gauge group, and a 1-form, $\theta$, transforming in the 14-dimensional vector representation. More formally, we assume that $P\to M$ is a $Spin(3,11)$ principal bundle, and $E\to M$ a vector bundle, associated associated to $P$ via the 14-dimensional vector representation. The fields consist of a connection on $P$, and a 1-form, $\theta$, with values in sections of $E$.

Posted by distler at 11:23 AM | Permalink | Followups (28)

## December 20, 2009

### MarsEdit

For many years, I was an enthusiastic user of ecto. Unfortunately, Adriaan gradually lost interest, and ecto3 languished – seemingly forever – as bug-ridden, user-unfriendly, beta software. Eventually, he sold it to illuminex, where it continues to languish (though I think they’re actually trying to charge people for using buggy, user-unfriendly beta software).

Anyway, to make a long story short, I’ve switched to MarsEdit, which – unlike ecto3 – is not the least bit painful to use.

To celebrate, I created some MarsEdit TextFilters.

Posted by distler at 11:19 AM | Permalink | Followups (3)

## December 14, 2009

### So Much For the Concept of “Tree Graph”

Topology meets botany.

Posted by distler at 10:35 AM | Permalink | Followups (5)