Rcjp's Weblog

December 29, 2009

Book: Does Anything Eat Wasps

Filed under: books — rcjp @ 5:10 pm

Just finished a set of three books by New Scientist magazine assembled from a column devoted to reader questions along with a selection of reader replies (the first title in the series is the title of this post.) The appeal of the questions and quality of the answers varied a great deal, but I learnt a few interesting points which I’ll attempt to abridge below:

The amount of water in a cloud is not different than the clear air around it, its only a temperature difference which has caused the water to condense into droplets and become visible.

I’ve never tried photochromic lenses but apparently they are temperature dependent and work poorly in warm weather, which somewhat defeats the purpose unless you are skiing.

Aluminium is much more reactive than we usually think because it quickly forms a protective oxide layer. Mercury can disrupt this, and then spread like wood rot, hence is banned on planes.

I also found some of the biological explanations interesting, mostly because I know embarrassingly little about this subject:

About a quarter of humans have a tendency to sneeze when going into bright sunlight. Its called a photic sneeze and happens because the protective reflexes of eyes and nose are closely linked. It is a well known hazard for combat pilots but was noted as early as the 17th century by Francis Bacon.

We don’t normally notice the Purkinje shadows which appear on the retina caused by the light having to pass through blood vessels and fibres (unlike a squid’s eye) because we are not good at registering stationary images. We only see stationary objects because are eyes are constantly jiggling about. If we undo this using eye-tracking technology, we can make objects disappear – Troxlers’s fading. We can only see the aforementioned shadows if we vary the angle of the light entering the eye via a pinhole in a card or shining light into the white part of the eye.

There is a physical section of the brain devoted to signals from different parts of the body called the somatosensory homunculus and fingers, for example, get much more brain to talk to than say the back.

The flu virus can live on a cash note for up to 17 days.

When a platelet (part of the bloodstream) encounters a wound it activates its integrins (surface receptors) enabling it to glue itself to the fibrinogen in the blood vessel. The non-cellular tissue in the body (the extracellular matrix – teeth, cornea, tendons etc.) is mainly produced by localised fibroblasts using fibre forming proteins: collagens and elastin (structural) or fibronectin and laminin (adhesive)

However in that last example I’m not really sure I learnt anything other than there were names for interesting things. The prospect of me being able to performing any calculations seems unlikely – I’m guessing protein dynamics isn’t the sort of subject you can dabble in. Maybe thats why I prefer basic physics: at least you get to play with the equations.

October 31, 2009

Book: “Things Snowball” by Rich Hall

Filed under: books — rcjp @ 5:18 pm

Just finished this paperback of short rants and tall tales warped with Rich Hall’s wry humour. Best voiced in your head with his elastic American drawl stretching the words and snapping them back. Picking it up a few times a day and reading through it like any other book isn’t a good approach though: you have to be in the right mood to laugh at his jarring nonsense. But when you are, his best work like stories of his grandfolks small nuclear plant, are head shakingly comical.

The cutting rants are always funny and sharply observed “Las Vegas is what America deserves … two thousand years of civilization and the planet’s most visible creation is a lit-up string of clip joints in the Mojave Desert”. After recently having to spent a few mostly vile days there I was left wondering if Vegas is the ultimate destiny of cities all over the world; the product of limitless money pandering to what the majority of ordinary people really desire. But I couldn’t quite capture a description of the objectless mass wanderings up and down the Vegas strip until I read Rich Hall’s description of visitors standing on the ‘people movers’ – those horizontal metal escalators walkways as being “…perfectly content as they creep along like God’s unclaimed luggage”. Genius.

October 28, 2009

Book: “Coders at Work” by Peter Seibel

Filed under: books — rcjp @ 11:04 pm

Over the weekend I read Peter Seibel’s latest book in which he interviews fifteen big name programmers using a set of similar questions about their programming approach and background.

Apart from a few slow sections it is a worthwhile read. Most interviews I’ve read before of famous coders gloss over interesting answers, but Peter is a practicing programmer and his personal interest shows through in attempting to dig a little deeper. Having said that, unfortunately I don’t think his probing turned up much gold. If you are hoping, as I was, to glean some productive techniques from these computing gods you are likely to be disappointed.

Anyway, on a first reading at least, I pulled out some quotes I thought insightful:

The physical properties of matter are such that 99.9 percent of the time you can understand it in aggregate. And everything you have to know about it, you can understand from dealing with it in aggregate. To a great extent, that is not true in the world of software.” … L Peter Deutsch

And later talking about advice from Jerry Elkind

…measure things. Even sometimes measure things you don’t think you need to measure. That [advice] had a profound effect on me.

Ken Thompson who, it is rather surprisingly revealed, doesn’t have code commit privileges where he works at Google said

“I’ve never been a lover of existing code. Code by itself almost rots and it’s gotta be rewritten. Even when nothing has changed, for some reason it rots.”

Grouping the interviews collectively is perhaps a wrong of me to attempt, but the book as a whole gives the impression of these hackers with sharp minds, primitive tools and not much interest in the software development literature. Quick to rewrite the code they don’t understand, mulling over problems in their head a few weeks, before jotting down a few data structures and debugging the resulting code with print statements.

I guess the book could have been titled “Greybeards Still A Work” as almost all are old-timers as evidenced by the answers to the usual opening question of “When did you learn to program”. The answer is often a lengthy description of some antique paper tape hardware for which they rewrote the operating system over a long weekend. So I’m not sure this book is a picture of an average “coder at work” and there is also a definite west-coast lisp slant to the book, not surprising really as Peter is a west-coast lisper!

There were a few lines of questioning that didn’t seem to lead anywhere like asking all of them if they’d read Knuths ‘The Art of Programming’ (mostly a little bit) and if they’d used literate programming (nope) and what they thought of C++ (they hated it). But, even with these dead ends, its definitely worth a read if only to confirm there isn’t much in the way of programming magic out there – just persistence and obstinacy and little inhibitions about rewriting code.

Finally, I can’t resist a few of quotes that made me laugh:

The whole Web is built on one mistake after another. We have this big pile of accidents.”…Douglas Crockford

Seibel: I think Larry Wall described [lisp] as a bowl of oatmeal with fingernail clippings in it.
Deutsch: Well, my description of Perl is something that looks like it came out of the wrong end of a dog.

and my favourite quote from Joe

…the problem with object-oriented languages is that they’ve got all this implicit environment that they carry around with them. You wanted a banana but what you got was a gorilla holding the banana and the entire jungle.… Joe Armstrong ”

Right, now I’m off to go and measure something I don’t think I need to measure…

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