Wednesday, April 30, 2008

Good Old Fashioned Old Testament Slavery


The Jewish festival of Passover celebrates the freedom of the Israelites from slavery in Egypt... hooray! but as it turns out Judaism is not actually opposed to slavery per-se. This fact does take some of the gloss off one of the high holidays.

The Torah contains numerous references to slavery: i guess by today's standards it seems pretty bizarre to condone any form of slavery... but at the time these laws were probably pretty liberal. Nevertheless, if you believe in the Torah as the word of God dictated to Moses - then you do have some explaining to do... "oh- they weren't REALLY slaves- more like servants!". Intricate and long winded rabbinical explanation here.


keep male and female slaves
keep 'hebrew' and non-hebrew slaves
beat them around a bit so they take a few days to recover
rape or have sex with female slaves as long as they weren't betrothed (implied but not stated)

keep them for more than 6 years (but you can keep their wives and children)
knock out a tooth or an eye (that'll set them free!)
kill them
rape or have sex with betrothed slaves (you'll need to make a steak offering at the steakhouse temple for that one).

Monday, April 28, 2008

Spiegelmers: Mirror Image Nucleic Acid Polymers

Monoclonal antibodies are all the rage at the moment- particularly for treating autoimmune diseases. Generally speaking, they are used to bind to, and inactivate, target molecules. A similar idea is to make a binding structure out of nucleic acids (the same thing that DNA and RNA is made of) - rather than long chains of amino acids.

I guess this is a little like "eating the recipe"! Nucleic acids are 'supposed' to be instructions for cells to make protein. They are usually the 'thinkers' rather than the 'doers'.

These molecules can be generated in a random fashion, then selected for their binding capability to the required target. Unfortunately, nucleic acid chains are not as stable as proteins, and are rapidly broken down by the body. One solution is to make them out of 'mirror-image' nucleic acids that cannot be broken down by the body's natural enzymes. (Spiegel is German for 'Mirror'). Clever.

Arvo Part's "Spiegel im Spiegel"

thanks to aron for the 'heads up'

R.I.P Jimmy Guiffre

I just happened to put on my DVD of "Jazz on a Summer's Day" yesterday ... and the kids started jumping around to the opening track... (here on youtube for your listening pleasure).
I found out who Jimmy Guiffre was 5 mins before i found out that he was dead- he died last week. I guess i just missed him! This is a song called "The Train and the River".
The film is a documentary of the 1958 Newport jazz Festival... up until yesterday my favourite part was actually the cellist smoking in a dark room and playing Bach. That and Anita O'Day.

Yeeee Haw! Old Crow Medicine Show.

Listening to the guys from "Old Crow Medicine Show" (alt-country-bluegrass)- you'd think they were 70 year old hillbillies. Great stuff! Great harmonies. I turn them up to past 11 and practise my cryin'/wailin' "vocal breaks" in the car or the way to work. I sound like a goat. I wish i could fiddle.

On this subject - yet another great podcast from Radiolab about the universality of country music. To summarise-country music only became popular when more than half the population had moved from the country to urban areas for work. The sense of longing for lost love, lost home, lost anything- makes it attractive to immigrants and losers the world over.

Friday, April 25, 2008

Distance -> Velocity -> Acceleration ->?

I find it fascinating that you can be charged/fined - not just for driving faster than the speed limit- but if your acceleration is too great. Apparently it is illegal to 'drag' race somebody stopped at a red traffic light- even if your car never actually exceeds the speed limit. Who knew? This is the sort of issue that should have been raised when i was studying calculus about 20 years ago!

But why stop at acceleration?

The rate of change of 'distance' is 'velocity'.
The rate of change of 'velocity' is 'acceleration'.

But what do you call the rate of change of acceleration, or the rate of change of the rate of change of acceleration or.... you get the point.

Believe it or not.. there actually are terms for these but apparently they're not all that widely accepted. Once again to the rescue wikipedia-

The rate of change of 'acceleration' is 'jerk' ...or possibly 'jolt' or 'surge' or 'lurch'
The rate of change of 'jerk' is 'snap'.. or possibly 'jounce'.
The rate of change of 'snap' is 'crackle'
The rate of change of 'crackle' is 'pop'
And since nobody else has claimed it i now official stake my claim to name the next kinematic derivative thus:

The rate of change of 'pop' is 'whoa!'

"I'm sorry officer- was it my acceleration, my jerk or my snap, crackle, pop or whoa!?"

Are There 7 Extra Dimensions?

Years ago i became fascinated by the idea of extra spatial dimensions after reading "Flatland", "The Planiverse", and (most of all) "The 4th Dimension and How to Get There" by Rudy Rucker. Subsequently, all of Rudy's books have been a GREAT disappointment as he veered towards kooky spiritualism.

Anyway- here's the take home message: it is very difficult for us to imagine a 4 dimensional world- perhaps impossible. One cannot point to a direction at 90 degrees to reality. You can, however, get a taste of the idea by imagining how a creature confined to a 2-D plane might perceive a 3-D solid object entering it's world.

A sphere passing through this 'flatland' plane would appear first as a point hovering in empty space, become an enlarging circle, and then a progressively smaller one once more- before disappearing completely. A 4 dimensional "hyper-sphere" passing through our 3-D world would appear as an enlarging then diminishing solid sphere in empty space.

Another lecture here. (couldn't embed it).

PicLens is Cool

PicLens is a great "plugin" /"add on" for your web-browser... (i'm using firefox on a mac with OS X) .

It allows you to view web images embedded in an infinite grid up against a virtual 'black wall'. From there you can fly over, zoom in and out- and play a slideshow. I use it for showing the kids stuff from flickr ... we watched a slideshow of "hot air ballons" over breakfast this morning.

It's so cool i'm thinking about setting this up in the waiting room. The flickr tag system is great: i tested it out with the search terms "calm" , "portrait", "landscape" etc and didn't find anything that could be thought to be porn.... Here's a youtube of the software in action.