Here's a mail I just sent to the author of the Bzip2 tools.
"If you can be bothered, please
email me to say you've got a
copy. It's nice to know where this stuff gets to."
Everywhere, I think is the answer, except the default OpenBSD distribution ... which is why I'm fetching source.
Thanks for making bzip2. I have always appreciated it.
I used to take tea with David Wheeler every day at Cambridge. I spent a decade at the Computer Laboratory, for some sins I must have committed in a past life, ... but tea with David Wheeler never seemed like punishment. He didn't have a lot to say, but what he did say was always pretty interesting.
He used to use bzip2 as his spam filter. Did you know that? He used it to measure the information content of his incoming messages M as the change in entropy between his "verified as spam" archive S and S+M. The change in entropy was just the difference in the size of the bzip2 compressed files. I was a sys-admin and had to help him once with some technical fiddling to get the mail message processing done automatically.
He used to think about physics in terms of information and entropy too. He had a Machian perspective. He told me once that a better physical theory was one which explained the data more concisely. In a sense he viewed physical theories as programs which reproduced the observed data from a compressed expression of the mechanical cause, i.e. the program. This was essentially Mach's view. I didn't ask David
whether he took Mach to Mach's extreme of saying that there was no truth independent of our ability to concisely describe phenomena.
So there, I hope this amuses you, and I hope you feel good about all that effort you put into making bzip2 a supremely reliable workhorse of the Free Software revolution.
And do you know David carried on working right to the end. Despite failing eyesight
and heart. He died in the bicycle shed seconds after arriving by bike
for work at 8am on a cold winter's day.
Best wishes,
Ian
One of my favourite quotes from David Wheeler: “Every problem in computing can be solved by another layer of indirection. But that usually creates another problem.”
ReplyDeleteHe once told me that he was slightly annoyed that most people quoted only the first sentence of that, not getting his point at all.
I didn't know it was David that said that! I claim the independent response to the foreshortened version that Piete Brooks so frequently emitted that I thought it was his phrase. It was certainly consistent with the way he sets anything up: which response is
Delete"and every problem in computer science is caused by an extra layer of indirection."
Or something like that. Of course, it's a long time ago, so I may just be imagining it. You will have to grep the sys-admin@cl mail logs to see if I am lying or not. Oh, you don't have suff. priv. for that, do ypuo You'll have to ask a sys-admin to do it for you :-)
Ian
I realised after writing that, that for David Wheeler, data cited as experimental evidence in favour of a physical theory had the same information content as an e-mail informing one about the availability of Viagra or a money-making opportunity involving the bank account of a deceased African dictator's mother-in-law.
ReplyDelete