alan crowe's Diaries
Print Story Mathematics anxiety and two kinds of panic
Logic & Maths
By Alan Crowe (Fri Dec 24, 2010 at 08:23:44 AM EST) landsburg, sex ratio, expectation (all tags)
In a far away land the natives don't much like children, but must have a male heir. So each married couple keeps having children until they have a boy, then they stop. Does this skew the demographics?

Every couple has a boy, but half get a boy first time: one boy, no girl. Clearly the stopping rule skews the demographics in favour of boys. On the other hand I've falsely spun the stopping rule as pro-boy. The rule is actually "keep having lovely girls until a yucky boy comes along, then give up in disgust". Many families consist of many girls and one boy. Clearly the stopping rule skews the demographics in favour of girls. On the third hand the demographics are fixed by the 50:50 ratio of boys to girls. The stopping rule is irrelevant.

So there is the kind of panic when you cannot tell whether your answer is correct or not. Steve Landsburg is blogging the second kind of panic. Terror inside.

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Print Story The Economist Magazine
By Alan Crowe (Wed Sep 16, 2009 at 07:52:14 AM EST) cyncicism, economics, disillusion (all tags)

When I was young, 15 or 17, I made several attempts to read the Economist Magazine in the school library. It was nihilist, left-wing agit-prop. My self-image was as a reasonable center-right person and I was put off, not least because the magazines cynicism seemed so similar to the teenage angst that I was actively rejecting.

That would be be around 1976. Now that I am nearly fifty I know that the Economist magazine is a right wing part of the establishment. The sophisticated reader can discern subtle nuances, separating pro-market from pro-business, separating those for whom "free markets" is a cloak and those for whom it is a creed. Nevertheless one is left to wonder: how did my young self get it so wrong?

Detailed justification of my teenage views inside, based on September 12th-18th 2009 print edition of the Economist.

(20 comments, 921 words in story) Full Story

Print Story Halving sums of squares
By Alan Crowe (Thu Apr 23, 2009 at 05:10:28 PM EST) fermat (all tags)

My previous diary entry concerned multiplying the sums of squares. Now I try to go the other way, factoring sums of squares. Since this is harder I make little progress, but make an interesting detour to visit the quarter-square multiplier.

(1042 words in story) Full Story

Print Story Sums of squares
Logic & Maths
By Alan Crowe (Fri Apr 17, 2009 at 03:10:33 PM EST) fermat (all tags)

Some numbers can be written as the sum of two squares. For example 113=7²+8² and 205=14²+3².

If we multiply 113×205=23165 is the result a sum of squares? Yes, 23165=146²+43², but why? 146 and 43 seem unrelated to any of 3,7,8,14.

(2 comments, 386 words in story) Full Story

Print Story The angles are wrong
Wizards and Hobbits
By Alan Crowe (Thu Jan 15, 2009 at 01:27:27 PM EST) cayley-dickson, sedenions, cthulhu (all tags)
In Lovecraft's Cthulhu Mythos a recurring motif is angles that are somehow wrong. As part of my project to transport an alarm clock to R'lyeh I have been investigating the trignometric formula cos²θ+sin²θ=1 but using complex angles instead of real ones.

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Print Story A problem with cryonics
Religion & Philosophy
By Alan Crowe (Sun Dec 14, 2008 at 05:33:03 AM EST) cryonics, anatman (all tags)

Over on Overcoming Bias RH and EY are advocating cryonics. Get frozen promptly, when your doctors give up and declare death. Perhaps one day medical science will be so amazingly advanced as to reverse the effect freezing and cure the end stage of your last illness, proving that todays saw-bones called "death" too soon.

Overcoming Bias subscribes to reductionist materialism. If undoing the damage of freezing is too hard the brain could nevertheless be dissected in sufficient detail to recover the data and initialise a whole brain emulation on computer hardware. You would wake up in the future's version of second life, and need to be equipped with a prosthetic, robot body before you could resume normal life.

Overcoming Bias also subscribes to evolutionary psychology, the sophisticated version. Most of the data is lost in pre-history, but evolutionary psychology nevertheless provides the philosophical framework for designing modern experiments and interpreting the results.

Strangely though, raise the subject of cryonics and all this is abandoned. The subject is debated without any suspicion that the concept of the self has limits.

(16 comments, 1567 words in story) Full Story

Print Story "Leaving the fold" on Overcoming Bias
Religion & Philosophy
By Alan Crowe (Tue Nov 11, 2008 at 09:38:08 AM EST) (all tags)
Overcoming Bias, the rationalist weblog, has an advice thread responding to Jo who faces a crisis as she loses her Christian faith.

The main post asks: Is there anyone who's been in this position - really, really invested in a faith and then walked away? I've refrained from posting in the thread because I've not had that experience, but I cannot avoid having opinions.

(16 comments, 842 words in story) Full Story

Print Story Igor
By Alan Crowe (Sun Nov 02, 2008 at 07:35:49 AM EST) (all tags)
Went to the cinema yesterday to see Igor. It is a cartoon for young children, about evil mad-scientists in the Baron Frankenstein mode. As an evil mad-scientist myself the obvious way to cover my embarrassment at going to see a children's movie would be to make a child and take it. Unfortunately, since the Alder Hey scandal it has been hard to get the parts.

(2 comments, 323 words in story) Full Story

Print Story Bayes and Jeffreys and Jaynes
By Alan Crowe (Mon Oct 20, 2008 at 12:53:28 PM EST) (all tags)
I'm reading Probability Theory: The Logic of Science.. The book requires applied mathematics at the advanced undergraduate level. This diary is purely literary, enjoying the fun of the book and the dramatic tension of the first two chapters.

(1107 words in story) Full Story

Print Story Thank God for the Fermi Paradox!
By Alan Crowe (Wed Oct 15, 2008 at 06:46:45 AM EST) (all tags)
Why are aliens coming to Earth? They haven't arrived yet so we cannot ask them, but we can guess. Poll inside.

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