From: Anthony R. Lewis, PhD
Date: 6/20/2005
Subj: Canonicity of Star Wars Games

In a number of the del Rey Star Wars novels, there are chronical lists (with incremental times since the previous film episode) of the stories and the media presenting them. In addtion to the del Rey novels, there are Scholastic Books, Comics, games, etc. Between episodes II and III there are:

LucasFilms Ltd. 	2
LucasArts Games	        2
Dark Horse Graphics	5
Scholastic Books	8
Del Rey Books	        8*

I would still prefer to own the Mint and the Bureau of Engravinig and Printing, but Lucas is not doing too badly.

Which ship would you prefer–the Millennium Falcon or the Dauntless?

I think you are telling me more about Star Wars literature than I really needed to know.

I expect that I prefer the Millennium Falcon; any ship that operate outside the space-time cone is just the ship for me.

… continued on next rock …

It’s my job to know.The Terra V and Polaris could also travel in hyperspace.

Of course it is your job to know. What, precisely, that “to know” covers is established by what you know. (Or so I am given to understand from “The Time Traveller’s Guide To The Recursive Arluis”.)

From: Anthony R. Lewis, PhD
Date: 6/20/2005
Subj: Flying to Denver

Not humor, but truth. One year I was going to fly to Midwestcon, which is held near Cincinnati. The direct flight from Boston to Cincinnati was about $900; the flight from Boston to Cincinnati to Columbus was $300. I would up flying to Indianapolis and renting a car.

When Deb flew out to Boston last year it turned out that a one way ticket cost quite a bit more than a round trip ticket. Go figure.

I’m quite confident that the bizarre pricing structure that airlines use has nothing to do with their frequent visits to the bankruptcy courts.

From: dns
Date: 6/18/2005
Subj: i need moneyback asap

did u receive my messages, dude ?

You really shouldn’t do that do. You might not be the brightest bulb in the chandelier, but it’s not right to go around calling yourself “a sap”.

From: Clint Olsen
Date: 5/18/2005
Subj: Yet another question about hashing

Thanks for replying so quickly. I’m actually in Maui right now and I’ll return on Sunday. Right before my trip I managed to get ahold of PJ Plauger’s paper called “State of the Art: Hash It” and he covers some of the work that was done on linear hashing – namely that of a guy named Larson and ‘Dynamic Hash Tables’.

The interesting thing I took away from this was that he allocates a set number of buckets as a power of two for instance, but he only releases the buckets for use one at a time as the load on the table gets higher. Of course, the idea here is to more gradually grow the table and this should smooth out the bumps that would normally be paid for a whole resize and re-bucket of all the items. Notice I didn’t say rehash since like you originally suggested we use successively higher order bits of the full-length hash value as we grow the table. This prevents expensive rehashing.

Of course, since you go to the trouble of reallocating the buckets anyway you actually might just want to move all pertinent the elements from the buckets at the lower end of the table to the upper since the load factor would drop dramatically after such an operation. I guess the only way to know for sure is just just code it up and see how it works. Kazlib uses the technique described in this paragraph – he responded to you in that original hash news article as well about the cost of a table resize in fact.

So, back to your original thoughts about probe sequences, Plauger definitely chose chaining for his implementation. I am still studying your comments about linear probing here. I originally was intending to use Kaz’s technique of masking to calculating the bucket value since this should usually be far less expensive than modulus. So, in the end rather than taking ‘mod m’ of the accumulated value, just mask it. In the context of double hashing, it would look something like:

H(K, p + 1) = (H(K, p) + h2(K)) & mask

Of course, with linear probing, h2 would yield 1 for all K.

From our original discussion about table size choices, we are definitely safe if the table size is a power of two and h2 yields an odd value as Knuth suggests. And ensuring this is not an expensive operation like finding an h2 that’s always relatively prime to the table size. We can just force the least significant bit to be 1 and we’re done.

I guess you’re probably correct that having some overhead is inevitable. If that’s the case, then using powers of two is probably easiest. The nice thing about that is that you can fairly easily in C determine what you’re largest table size can be and you can parameterize that in whatever size an unsigned long is on that architecture. So, if you have 64-bit ints on your machine, you’re good to go for massive table sizes, and the code doesn’t have to change one iota. Making table sizes prime or using fibonacci numbers means you have to continuously update tables of these values as the longs get long(er) since they are a) Pain in the ass to calculate or b) A waste of CPU cycles to calculate, and you just want them available to the library.

I think I mentioned that one of the caveats of double hashing though is that over time with excessive insertions and deletions, you get tables that are littered with ‘deleted’ spots on them, so checking for the existence of a key can get more and more expensive since you must terminate an unsuccessful search on a clean empty slot. Otherwise you may not thoroughly check through a valid probe sequence for a particular key. Two ways of dealing with this in the papers have been to:

a) Completely reinsert all keys into a fresh new table periodically. I don’t care for this idea at all. It’s expensive.

b) On deletion, check the table for a key that might have been displaced on a probe sequence to that slot and move it there. That might mitigate the deleted bits problem, but this makes deletion expensive since I don’t know offhand how to ‘find’ any key that was bumped since that slot was already occupied. It seems like you’d have to check all the valid keys in the table to find out if it originally hashed to that slot.

Chaining really works well for an unsuccessful search. You just check the chain and you’re finished. No fuss.

Thanks a lot for your help so far. I really want to get my head around this problem and make robust hash table implementation. It’s fun solving these sorts of problems.

My apologies for not getting back to you; life has been rather busy recently. I have followed the usenet discussion on hashing; it has been informative. My preference is for chaining – it is flexible and makes for easy changes of table size.

I tend to agree with Paul Hsieh about using powers of two table sizes and storing the full hash. One argument for storing the full hash is that it reduces comparison costs – one can compare against the full hash rather than comparing against the data. The thought is that comparing strings can be relatively expensive; however it is cheap (on average) to compare random strings (assuming that the data of interest is strings) for inequality. Verification is relatively expensive; however we want to do that anyway.

A more cogent reason for using powers of two and storing the full hash is that table resizing is much cheaper than when the table size is a prime and the full hash is not stored.

An argument against chaining that I have not seen is that for large tables following links may break locality. I suspect that it is faster (at the price of some extra space usage) to provide small arrays rather use linked lists; however I haven’t done any studies on this.

If you are going to use double hashing I commend to you Knuth’s “Selected Papers on Analysis of Algorithms”, Chapter 7 on “Ordered Hash Tables”.

From: Joe Fox
Date: 6/14/2005
Subj: “Thoughts on Update as a Software Maintenance Tool”

Thoroughly enjoyed reading your 1981 article on the old CDC “UPDATE” software maintenance utility. I loved it back in the late 70s, never have seen anything like it sense. (Almost impossible to explain to people, even software professionals!) Alas, I suspect it went away with the CDC machines of that era…

By chance, I also utilized an IBM VM/CMS system circa 1980, and did try out the “UPDATE” utility there. As noted in your ’81 article, it’s use was good for one set of changes — after that the line number issue got in the way, circumventing any resemblance to the CDC utility.

Now, you probably know that CRAY implemented virtually the same UPDATE system as CDC had on their computers back then. What you may NOT know is that someone wrote a VERY CDC-UPDATE like utility for use with VAX/VMS, around 1981 I believe. Other than some required syntax changes and file handling (e.g., VMS allowed multiple versions of a file at the level of the file specification — e.g., FILE.DAT;1 and FILE.DAT;2), it was absolutely one-to-one with CDCs utility. The name of the utility was “UPDATE-PLUS”. The author may have been one “Christopher C. Fulton”, but my memory is really hazy about this. I do know that the company that sold the UPDATE-PLUS for VAX/VMS operated out of California, possibly San Jose.

I hadn’t heard about UPDATE-PLUS. I did know that the later versions of CDC Update provided for automatic difference calculation. The core Aide-de-Camp (later TrueChange) owed a lot to CDC Update. It has change-sets that are yankable (with a different terminology.) It doesn’t have editable change decks though – it uses automatic difference calculation.

Incidentally, in the world of Configuration Management I am “the father of change sets” even though I keep saying that CDC did it all thirty odd years ago. It is really quite surprising how much good technology has simply been forgotten.

Anyway, thanks for writing.

From: rosy rag
Date: 6/11/2005
Subj: link exchange request

Hello, I am the Links Exchange Supervisor for Flower Market([email protected]), and I came across your Website while doing a Google search. I am interested in setting up a link exchange between your Website, and Flower Market to maximize our reach to our visitors. I strongly believe that we can mutually benefit from a reciprocal link exchange as we share similar target audiences and interests. If you are interested in linking to Flower Market, please respond to this email with a brief description of your Website/business, other similar URLs you own and where you intend to place the link to Flower Market.

I hope we can take advantage of this great opportunity, and look forward to hearing back from you. This is my info:

Title :- Flower Market
URL :-http://www.flowers-market.com
DES :-flowers and roses: cheap flowers, birthday flowers, mothers day flowers

Somehow I doubt that you really do want a link exchange with my site – at least there is no rational reason why you would want one. For that matter I wonder what search criteria you used that might possibly suggest that my site would be a good candidate for a link exchange. Could it be that you looked for all sites containing the word “flower”?

Be that as it may, your request will appear in my site in the correspondence column. It may well chance that some reader may read your letter and will be intrigued enough by it to visit your site. If that should chance, I will be happy for you.

From: Stefan Andrew Nicholson
Date: 6/13/2005
Subj: san language

It was very interesting to see that you have named your new programming language San Language. I have also got a San Language (not related to computers – but a thought language) that I developed in 1973. The name came from my initials: Stefan Andrew Nicholson, and also because it was a Symbolic Art Notation language.

Basically it is a spatial graphics language (every part of grammar) that is learnt in 2 hours, and can be interpreted by any nationality without the need for spelling, talking or alphabet. I came across the African San Languages much later on (with the clicks).

Good luck with your new computer language. I am a BASIC programmer myself, but now have sucumbed to Access. I intend using Basic Stamp for constructing electronic instrumentation. I thought I would drop you a line to say hello.

That’s rather neat. As it happens I don’t have a middle initial, let alone one that is a vowel, so I can’t name it after myself.

From: digitec
Date: 6/13/2005
Subj: dude, i need my money – 2

please, i hope, it was your mistake.. return my money, please.

Hey dude, I need your money too. Send some more; the last batch has run out.

From: Robert Mc Farlane
Date: 6/13/2005
Subj: sith love

I was reading something on your web site at 4 in the morning as I had had a few thoughts about Darth Plagus “the wise” Darth Sidiouse’s master. During the concert Sidiouse mentions that he didnt know how to stop people from dieing. Near the end he mentioned that he would be able to if he combined forces with Anakin. If he wasnt capable of stopping people from dieing the ability to create life from midiclorians.

This business of keeping people from dying has rather vague boundaries. He kept Anakin from dying so we can give him some credit for having the power to keep people from dying. In the case of Padme, however, what was needed was the power to void a prophecy. It is possible that Sidious could have stopped her from dying if he had been present, though what she would have been like is open to question; she would have been physically alive with no will to live.

Almost certainly Sidious was the “other Jedi” who ordered the clone army. He set up the training so that the clones would respond to order 66 without question.

It is open to question whether it was Sidious or his master who caused the midiclorians to conceive Anakin. Either way Anakin was a Sith project. However there is a nice bit of irony here. The Sith knew about the prophecy. They moved to preempt it by creating Anakin whom they intended to be the greatest Sith of all. In the end, however, Anakin did destroy the Sith.

Telling the truth is the most delicious form of lying.

Anakin/Darth Vader did bring balance to the force. The dark side had been suppressed; the Sith got their turn at being on top and the fossilized Jedi order was eliminated. In turn the Sith were eliminated after a generation.

Good point.

I doubt that the computer games are canon. The movies and their novelizations are. I have an impression that the authorized novels are also canon.

In any case, yes, I enjoyed the film.

From: Peter Neilson
Date: 6/10/2005
Subj: microevolution squirrels

I have noticed that there are, or were, two varities of the common gray squirrel that are differentiated by their patterns of flight from danger. I’ve seen the identical phenomenon in Massachusetts and here in North Carolina. The effort involved in observation does not require passage to the Galapagos Islands.

I call these two varieties zig-zag and straight-through. The zig-zag runs a fast-changing path, in order to throw off predators. Faced with an oncoming motor car, the zig-zag, nearly out of harm’s way, turns and runs back underneath the wheels of the car. Straight-through squirrels do not turn back, and often avoid getting squished.

Over the last 50 years I have seen the zig-zag become far less prevalent in city areas, and now it is dying out in rural areas as well. What would old Trofim Denisovich think?

An evolutionary just-so story might run something like this: Squirrels have two options available to them – run zig-zag to avoid predators, and run straight away to get out of the way of galumphers (creatures that might step on them). The choice of strategy being fundamental to survival, it is genetically determined. In the past century the number of wolves has declined dramatically whereas the number of automobiles has increased dramatically. The straight-aways survive and natural selection triumphs.

There are critics of such stories; there are always critics. My take is that squirrels, much like creationists, are not too bright. When confronted with a threatening situtation they initially choose a response at random from their repertoire. Those who choose poorly die. Those who choose fortunately repeat their response in the future, much like the pigeons that stand on one foot to induce grain to fall from the sky because that was what they were doing when grain was last scattered before them.

I opine that old Trofim Denisovich would feel vindicated. It didn’t seem to take much.

From: dns
Date: 6/11/2005
Subj: dude, i need my money

I resist to wait. I need full moneyback, or …

No full moneyback here. Try the NFL; maybe you can get some fullback money.

From: Jon Edelbaum
Date: 6/8/2005
Subj: Darwin Awards, 2005

It is with truly great sadness that I am unable to find the 2005 awards. Alas and alack, what is one to do, and be careful how you answer that!

You time travellers are all alike, always being pushy.

From: Davgil
Date: 6/8/2005
Subj: Richard Harter’s World

Some sites deserve a comment, most don’t. Yours does, this is mine.

And an admirably concise comment it was, too.

From: Peter Neilson
Date: 6/1/2005
Subj: try this …

In your web page http://richardhartersworld.com/cri/humor.html try clicking on the entry labelled “One liner book reviews.”

I don’t quite know how that happened (it must be alphonse’s doing) but I will attend to this matter almost immediately.

… continued on next rock

RSN?

Just so.

From: Alison Pakula
Date: 5/23/2005
Subj: Thanks

hello, you might want to change some of the title’s of Jane Austin’s novels, as what you have written down is incorrect. It is “Cold Persuasion”, “Pride and Prejudice”, “Mansfield Park” and “Sense and Sensibility” rather than “Colt Persuasion”, “Pride and Precipe”, “Winchester Park” and “Fence and Fencibility”.

The noted British author, Jane Austen, did indeed write “Pride and Prejudice” etc. However she is not the celebrated, albeit fictitious author, “Calamity Jane” Austin, whose works are detailed in the bibliography page on my web site.

Do you know (and I am sure you will be shocked to hear this) there are people about who misspell “Jane Austen” as “Jane Austin”? I regret to say that there are even people who never bother to verify the research they do using the web, people who mistake parody and satire for fact.

Be all of that as it may, I appreciate your writing and your calling attention to this matter.

From: Beverly
Date: 6/1/2005
Subj: Thanks

I’ve been a reader of your website for about seven years now. It is very entertaining and full of witty humour. That’s why I keep coming back. Keep up the good work.

Thank you for the kind words – those are the kind of words I like to receive. Seven years is quite a long time. There aren’t many who have been reading my site from its beginning but there are some. Why I heard from one just the other day. He wrote in crayon of course. Poor chap, they won’t let him have anything sharp.

It was good to hear from you; thanks for writing.

From: Keith Sumrall
Date: 6/2/2005
Subj: question about radiocarbon dating

What is the threshold of the radiocarbon dating process? Can it tell how old human bones are within a year or is it more like thousands of years? Just curious for a story I am writing.

It’s inbetween. http://www.c14dating.com/int.html gives an accuracy of plus or minus 16 years for modern liquid scintillation dating. I hope this helps.

From: Tom Cicillini
Date: 6/3/2005
Subj: Top 10 Philosophy questions response

you are an idiot.

Many have said it, and I applaud you for being among their number, particularly since it appears that your conclusion is based upon a paucity of evidence, with that evidence being of a dubious sort in part and in whole. One can only admire such a triumph of imagination over reason.

From: Meredy Amyx
Date: 5/23/2005
Subj: Densa

Hi, Richard,

No, I don’t think John had anything to do with the so-called Densa quiz. If you’re talking about the one that starts with “Do they have a Fourth of July in England,” that was on the xerox circuit before the Internet was born; one of my teachers passed it out to my class when I was in high school in the early 1960s, and I later saw it used as an icebreaker at some kind of training session. It wasn’t called anything–it was just an untitled list of mildly tricky questions.

I’ve seen another one somewhere that also calls itself a Densa test, probably in a Mensa newsletter (though maybe not of Mensa origin). I believe it turned up long after Densa was invented, and I feel confident in saying that John had no part in its authorship. The Densa idea was not an end in itself, and I never knew him to have any interest in developing it beyond the aim for which it was created. John used Densa for setups for matrix puzzles–you know, the sort that consist of a series of statements from which you have to figure out who lives in the green house and who owns the zebra. He used Densans as characters in the storylines that formed the basis of the fictitious content to which the puzzle logic was applied. His original Densa puzzle and an account of its history are appearing in a Mensa publication next month in an article under my byline.

You could be right that someone other than John came up with the Densa concept independently. But it is also true that John did come up with it, and came up with it first. If someone else did so later, without being influenced by John’s creation (which would have to mean not being a Mensan and not seeing Mensa newsletters), that would be pretty hard to prove or disprove.

However, the Mensa world is pretty small, all in all, and back in those days any mention in, say, a newspaper crossword puzzle or a TV show was a big deal. If someone outside Mensa had created such a parody and published it on a big enough scale to get known, someone in Mensa would have heard of it and passed it along. I was very close to the national organization throughout most of two decades, mid-seventies to mid-nineties, and would have been sure to hear of such a thing.

It is also easy to say how obvious the idea is after it’s been pointed out; see Picasso’s “Head of a Bull” for a prime example of that phenomenon.

I enjoyed “The Chameleon.”

Ever hear of Howard Chace, author of Anguish Languish? He used to sign his letters “Sin-cheerily.” Your closing made me think of him.

Thanks for writing back. I did some web searches and I think that the situation is this: There were some independent inventions of the term “densa” outside of Mensa; however the usage within Mensa clearly is based on John’s version.

The content of the densa quiz precedes the title. I don’t recall seeing it circulating in xeroxed sheets but I am sure you are right.

The title, however, appears to have originated in www.densa.com. Judging from my searches it appears that there were two different densa.coms, one circa 1999 and one circa 2005. The earlier one had the quiz which circulated in email; the latter has quite a number of links including quizzes.

To be honest, I was never very enthusiastic about the matrix puzzles nor the various truth-teller/liar puzzles. Once you have gone through a few they are all much the same. I rather liked the Caliban’s will puzzle (I have a copy at http://richardhartersworld.com/cri/1998/caliban.html) by Dudeney. A good puzzle makes your jaw drop.

I hadn’t heard of Howard Chace. If I get a chance I shall check him out. The odds are against it – nowadays my backlog of books to read keeps growing.

Again, thanks for writing and keep up the good work.

From: Labove8
Date: 5/27/2005
Subj: love it

i stumbled onto this site and love it.keep it up

I shall. It is my duty to do so for the sake of my admiring readers – both of them.

From: tasha
Date: 5/23/2005
Subj: hello

im doing a home project on the sioux for fun and wanted to know if you could email me some info because its hard to find the right stuff i need? could you? please and thankyou!!:) just send some basic things because im very busy and would LOVE to finish my project as i find it of the most facinating people and how they lived and saw the land and the world and ofcourse the white people!

Your best bet is to do a google search on Sioux. I do have a web page, Decline and Fall of the Sioux Nation, that has some material, albeit not a lot. My apologies if this isn’t much help. If you have more specific questions feel free to write; I may be of help.

… continued on next rock

hello, im tasha, and i was wondering if u could help me in the sioux children section because i cant seem to find ANY good info on them eg-education, living style, work, ect
can u help me?
if so tnx a bunch!

I’m afraid I can’t help you much there except for this: The South Dakota PBS has a wonderful history program that they sometimes run late at night about growing up as Sioux and growing up as Pioneer. If you can find their address they may be able to help you. Here are some web sites you might check:

http://www.aktalakota.org/
http://www.answers.com/lakota&r;=67
http://www.pbs.org/itvs/homeland/lakota.html
http://puffin.creighton.edu/lakota/

If you do a google search on Lakota you will turn up many pages; there should be something there that you can use.

From: Anthony R. Lewis, PhD.
Date: 5/23/2005
Subj: A bad spell of wheather

Dear Mr. Harter,

apparently South Dakota has stolen Spring from New Enlgand. Please return it.

But of course you may have it back – once we are done with it. Would the fourth of July be alright?