100 years of Chinese history

Posted on June 23, 02009 | Leave a Comment
Filed Under Inspiration, Journal

Mapping time based on genealogy and national history is a project recording 100 years of Chinese history. Each date has been painstakingly rendered by hand by "graphic musician" Haohao Huang. More photos on Flickr.

via Infosthetics

Will Flash for cash

Posted on June 5, 02009 | 4 Comments
Filed Under Development, Journal

Well I had "the conversation" this morning and it looks like my employer will be making a big round of redundancies next week. I don't tend to talk about work here (this is the home of my personal projects) but this is a the big one so forgive me this once.

If anyone is in need of an experienced Flash developer in the London or Brighton area then please get in touch. My email is john at this domain. I have a new portfolio of work and cvs are available on request.

Minkowski Spacetime

Posted on May 21, 02009 | Leave a Comment
Filed Under Development, Drake, Journal, Kepler, Latham

ts_hminkowski_zoom

"The views of space and time which I wish to lay before you have sprung from the soil of experimental physics, and therein lies their strength. They are radical. Henceforth space by itself, and time by itself, are doomed to fade away into mere shadows, and only a kind of union of the two will preserve an independent reality."

Hermann Minkowski, 01809

Time and Space
In the previous post I surmised that current temporal standards offer poor support for historical data. I also know that modelling time at deep timescales is going to throw up some new problems. The thing is, once you start messing around with time outside of historical systems like calendars you run into another dirty little secret. Time and space are related. We've known this for over a hundred years but temporal specs are all geared towards events in the short now, so fiddly little problems like relativity are conveniently ignored.

Even if I ignored relativity, I can't ignore space. Recent temporal innovations like daylight saving time and the timezone system are all local modifiers based on spatial coordinates. What I find odd is that I haven't encountered a single specification that tries to treats time and space equally.

Hermann Minkowski
The German mathematician Hermann Minkowski (1869 - 1909) was the first to formalise the notion that space and time are not separate. He proposed that the best way to understand Einstein's special theory of relativity was to use a 4 dimensional space he called spacetime. It's often referred to as Minkowski spacetime to differentiate it from a slew of other modern multi-dimensional theories.

Getting your head around the ideas of relativity and spacetime isn't as hard as you might expect. I found some great articles here that walk you through all the concepts using simple examples. Getting my head around the mathematics of spacetime is another thing entirely!

Minkowski image via AIP Emilio Serge Visual Archives

Revelation

Posted on May 14, 02009 | Leave a Comment
Filed Under Development, Drake, Herodotus, Journal, Kepler, Latham

'The ancient of days' by William Blake, 01794

Getting external data into Herodotus is an important part of the project. Data can be encoded in a wide array of formats and they all have to be parsed into Actionscript Value Objects. I've yet to define the metadata for these VOs so in an effort to find some commonality I spent much of the last few months digging through a mountain of temporal specifications, projects and APIs. It's been hard work and a journey peppered with surprises and revelations. Over this and the next two posts I hope to cover some of what I've learned and how this has shaped my semantic model of time.

The semantics of time
The properties of time are elusive. It's a fundamental concept with a myriad of definitions, each dependent upon the experiences and requirements of the individual or group who defines it. Disciplines as diverse as physics, chemistry, biology, astronomy, theology, philosophy, history, music and politics have all had a hand in shaping our definitions of time.

It's fascinating to watch different people approach the same problem. Some attempts make you want to scream "oi, no!", and others have you immediately reaching for your notebooks; throwing out old ideas in favour of new, each revelation informing your overall understanding of the problem.

The fundamentals and architecture of time require some deep thought and on the whole this is evident in the specifications I looked at. The introduction to the ISO8601 specification gives a good introduction to the basic temporal concepts of a Timeline, an Instant and an Interval. The Time ontology in OWL describes them in a little more detail. These three concepts seem to be universally applied or at least implied in all of the specs I looked at.

Old Father Time: ISO8601
In a review of Temporal Web Standards I showed that almost all web standards for DateTime have their roots in the ISO8601 specification. This was great because it gives me the commonality I was looking for.

iso8601

Unfortunately this common ancestry throws up another problem, but before I get into that it's worth noting the main innovations to take from ISO8601:

Dates are human readable.
Dates are stored internally in UTC and converted to local time as required.

When date and time are represented as strings they are formatted in order of granularity, from largest to smallest. This offers the following advantages:

Dates are language neutral.
Dates are unambiguous.
Dates are machine sortable.

Julian 1.1
Now for the bad news. ISO8601 models our modern civil "Gregorian" calendar. Introduced in the Inter gravissimas papal bull by Pope Gregory XIII this system of measuring time reformed the earlier Julian calendar. The difference between the two calendars is small - only a slight change to the leap year rule to correct the drifting date of Easter. In software terms the Gregorian calendar would be considered a patch: it's Julian 1.1.

The problem of dating historical events with ISO8601 is really one of practicality. The reform came into effect, in Catholic countries at least, in 1582. The thing is (rather obviously) a lot of history happened before then. These sorts of dating problems aren't new to historians but the conversion to Gregorian, and often back again, can be non trivial.

For example, meet Tom. Tom is a historian studying the French Revolution. He has found a date on a document that uses the short-lived put completely wonderful French Republican calendar. The FRC was a metric calendar (10 days in a week, 10 hours in a day etc.) adopted very briefly alongside the rest of the metric system. If Tom wanted to store information on the web about this document he would have to convert the date from French Republican to Gregorian.

The Proleptic Gregorian Calendar
The common response of spec writers to the problem of historical dating is to use the proleptic Gregorian calendar. A proleptic calendar is one in which the calendar rules are extended backwards in time before when the calendar was introduced. Now this sounds like a great idea until you actually try and use it.

Meet Tom again. This time he is studying the life of Julius Caesar. Caesar was born when one of many permutations of the Roman calendar was in effect, and he died two years into the counting of his eponymous Julian calendar. Dates in his life require conversion from at least two different calendar systems into the proleptic Gregorian. Just to add to the complexity all of those dates are considered BC in the Julian/Gregorian calendars. While most implementations of proleptic Gregorian (including ECMAScript) happily count zero and on into negative numbers, the proper BC/AD (or BCE/CE if you prefer) system doesn't count a year zero. 1AD is preceded by 1BC. Conversions like this are complex and error-prone. I really don't think the proleptic Gregorian is a very practical storage solution.

As if I haven't rammed the point home enough then consider a further example. Meet Dick, he's a geologist studying the Cretaceous Tertiary boundary. What is 65.5 million years ago in Gregorian? It's all a bit fuzzy. Don't even bother asking Harry the cosmologist.

The revelation
Once you realise there is no practical support for historical events prior to 1582 it quickly becomes obvious why we don't yet have a deep-zoom for history. No online support = no online data. To pull this off I need a model of time (and space, but I'll get into that later) that goes back beyond the common Gregorian calendar and in fact beyond any calendar into the timescales of geology and cosmology.

La Machine à Ecrire le Temps

Posted on April 30, 02009 | Leave a Comment
Filed Under Inspiration, Journal

Baselworld is the world watch and jewellery show held every year in Basel, Switzerland. It attracts around 100,000 visitors and is one of the most important events in the horological calendar. One of the stars of this year's show was not a watch but La Machine à Ecrire le Temps (translation: 'The Machine that Writes the Time'). This beautifully crafted "horological sculpture" contains 1200 components and took almost ten years to construct.

Much like the Corpus Clock or the Clock of the Long Now the machine is as much art project as it is timekeeper. It was designed and built by French watchmakers Montres Jaquet Droz and pays homage to the company's founder Pierre Jaquet Droz, who in addition to being a skilled watchmaker was also a master creator of mechanical dolls and automata.

via Watchismo and Long Now