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Monday, May 30, 2005

Solar System Live Goes Stateless

For more than a decade, the dynamic image generation resources at this site: Earth and Moon Viewer, Solar System Live, and Your Sky, have returned custom Web pages with dynamically generated embedded images by returning HTML including a link to an image kept in an ephemeral files directory. Images in this directory are intended to be immediately fetched when the requester's browser displays the page, and are purged automatically after a decent interval has elapsed.

This architecture has worked well, but it has some drawbacks. First of all, despite every standards-compliant way to inform downstream caches that the dynamically generated images are ephemeral and should not be cached, many of them (hello, Acephalics On-Line!) attempt to cache the images anyway and generate thousands of moronic HEAD requests to see if the images remain in the cache long after they've been downloaded by the users who requested them and consigned to the bit bucket. Then there are the "creative" users who, unable to figure out how to request a dynamically generated image delivered directly to their Web application, parse the HTML returned from the request and embed the temporary image name in a Web page or, even worse, automatic retrieval program which hits the site over and over. One particular idiot has been requesting a long-gone image from Earth and Moon Viewer every five minutes for more than three years; and the fact that I've blocked the IP address from which these requests originate has not deterred them from raining upon my firewall.

These are more or less minor annoyances compared to the constraints the temporary image architecture imposes on deployment of a server farm. When user requests are load-balanced across two or more servers, absent some scheme for session persistence, there's no way to ensure the reference to the dynamically generated image referenced in a reply page will be directed to the server on which it is actually stored. One can cope with this (as I currently have) by session persistence gimmicks, but doing so adds complexity to the load balancing process, constrains the ability to spread load across servers, and marginally reduces the fault tolerance of the server farm.

Today, I put a new version of Solar System Live into production which replaces the temporary image scheme with entirely stateless dynamic image requests--all information required to generate the image embedded within a reply page is encoded in the URL specified as the src= of the image inclusion within it, and hence the image can be generated by any server to which it is directed. This eliminates the need to cache temporary images on the server, and removes the temptation for users to dig their locations out of reply documents and make foredoomed links to them.

This is a major re-architecting of this Web service--I've kept the old version around in case somebody has a legitimate need to access the cached images until they update their client program. The new version also returns 100% compatible XHTML 1.0, and all the static documents and help files associated with Solar System Live have been validated as XHTML 1.0 compliant. If all goes well, I'll migrate Your Sky and then the biggie, Earth and Moon Viewer, to the new architecture.

Posted at 00:41 Permalink

Sunday, May 29, 2005

Reading List: Men in Black

Levin, Mark R. Men in Black. Washington: Regnery Publishing, 2005. ISBN 0-89526-050-6.
Let's see--suppose we wanted to set up a system of self-government--a novus ordo seclorum as it were--which would be immune to the assorted slippery slopes which delivered so many other such noble experiments into the jaws of tyranny, and some dude shows up and suggests, "Hey, what you really need is a branch of government composed of non-elected people with lifetime tenure, unable to be removed from office except for the most egregious criminal conduct, granted powers supreme above the legislative and executive branches, and able to define and expand the scope of their own powers without constraint."

What's wrong with this picture? Well, it's pretty obvious that it's a recipe for an imperial judiciary, as one currently finds ascendant in the United States. Men in Black, while focusing on recent abuses of judicial power, demonstrates that there's nothing new about judges usurping the prerogatives of democratically elected branches of government--in fact, the pernicious consequences of "judicial activism" are as old as America, winked at by each generation of politicians as long as it advanced their own agenda more rapidly than the ballot box permitted, ignoring (as politicians are inclined to do, never looking beyond the next election), that when the ideological pendulum inevitably swings back the other way, judges may thwart the will of elected representatives in the other direction for a generation or more.

But none of this is remotely new. Robert Yates, a delegate to the Constitutional Convention who came to oppose the ratification of that regrettable document, wrote in 1788:

They will give the sense of every article of the constitution, that may from time to time come before them. And in their decisions they will not confine themselves to any fixed or established rules, but will determine, according to what appears to them, the reason and spirit of the constitution. The opinions of the supreme court, whatever they may be, will have the force of law; because there is no power provided in the constitution, that can correct their errors, or controul [sic] their adjudications. From this court there is no appeal.
The fact that politicians are at loggerheads over the selection of judges has little or nothing to do with ideology and everything to do with judges having usurped powers explicitly reserved for representatives accountable to their constituents in regular elections.

How to fix it? Well, I proposed my own humble solution here not so long ago, and the author of this book suggests 12 year terms for Supreme Court judges staggered with three year expiry. Given how far the unchallenged assertion of judicial supremacy has gone, a constitutional remedy in the form of a legislative override of judicial decisions (with the same super-majority as required to override an executive veto) might also be in order.

Posted at 03:07 Permalink

Thursday, May 26, 2005

Reading List: Founding Father

Brookhiser, Richard. Founding Father. New York: Free Press, 1996. ISBN 0-684-83142-2.
This thin (less than 200 pages of main text) volume is an enlightening biography of George Washington. It is very much a moral biography in the tradition of Plutarch's Lives; the focus is on Washington's life in the public arena and the events in his life which formed his extraordinary character. Reading Washington's prose, one might assume that he, like many other framers of the U.S. Constitution, had an extensive education in the classics, but in fact his formal education ended at age 15, when he became an apprentice surveyor--among U.S. presidents, only Andrew Johnson had less formal schooling. Washington's intelligence and voracious reading--his library numbered more than 900 books at his death--made him the intellectual peer of his just sprouting Ivy League contemporaries. One historical footnote I'd never before encountered is the tremendous luck the young U.S. republic had in escaping the risk of dynasty--among the first five U.S. presidents, only John Adams had a son who survived to adulthood (and his eldest son, John Quincy Adams, became the sixth president).

Posted at 00:54 Permalink

Wednesday, May 25, 2005

Direct Access to Global Weather Images

This isn't exactly news, as most of the the links I mention in this message have existed for years (the water vapour image links are new, however), but previously I've only furnished this information on demand to those who write to request it. This posting not only makes the information generally available, but can be cited in response to future queries, avoiding the need to dig up the information from scratch each time.

Earth and Moon Viewer provides access to current weather satellite imagery made available by the Space Science and Engineering Center of the University of Wisconsin. These images are transformed from the Mollweide projection in which they are published into a cylindrical projection suitable for mapping onto a sphere. In addition to the change in projection, the images are contrast stretched and composited with a cartoon background of sea and land.

Programs and Web resources which require current weather data may obtain these raw images from the following links. These images are updated no more than four times a day--downloading them more frequently is counterproductive and, in case of egregious abuse, may result in denial of access to Fourmilab.

The following list provides direct links to the current weather imagery, with each URL linked to a pop-up window which will display it.

Posted at 20:38 Permalink

Tuesday, May 24, 2005

ETSET Version 3.1.1 Posted

Version 3.1.1 of ETSET is now available for downloading. ETSET is a utility which translates electronic texts written in human readable form into LaTeX (and thence to PostScript and PDF, if you wish), HTML (either single document or individual chapters with navigation links), or Palm Markup Language (PML) to produce eReader books which can be read on a variety of PDA and smart mobile telephone platforms.

This is a minor bug fix update to Version 3.1 which corrects a problem which caused LaTeX and PML format output files to be truncated when the program was built with GCC 3.x. The problem was a compiler/library interaction which would also affect version 3.0.1 were it built with GCC 3.x. There are no functional changes in this release; the Win32 binary executable has been rebuilt with the fixed source code even though the file truncation problem did not manifest itself when the program was built with Visual C++.NET for that platform.

Posted at 17:52 Permalink

Never Make a Speech on Friday the Thirteenth

If you follow this narrative regularly, you may have noticed a gap between the last entry on the 11th of May and the burst of recent activity (some backdated, but without intent to mislead--read on for details).

There are few things I detest as much as giving speeches, and given that proclivity you'd think I'd be doubly averse to signing up for a speech on Friday the Thirteenth, but DEWS and its ancestors have contributed mightily to my career and combobulation in the last decade and a half, so I'm always willing to do my part to explain why high technology companies should put Western Switzerland at the top of the list when they're considering a place to base their business in Europe. I'm not a great public speaker; I look at speaking engagements the way pilots regard landings--any one you walk away from is a success--and I hope that if the audience doesn't understand a single word I said (because I tend to speak a bit fast to get it over with), they'll at least think my heart was in the right place.

Never sign up for a speech on the Friday the Thirteenth! It's like crossing the NCGA. Anyway, after spending far more time than I can explain or justify on this speech (I usually budget about one hour of preparation per minute of time at the podium), I buttoned up the speech and went off to enjoy three hours of sleep before departing to give it. The next morning, I got up, got ready to go, walked up a flight of stairs to get a copy of the transcript of the speech from the printer and . . . woke up about ten seconds later looking at the floor. This was bad. Apparently my heart was not in the right place, and this was one I might not walk away from.

The show must go on, so I called the organisers of the conference and FAXed the transcript to them so somebody could read it in my absence or copy and distribute it to the attendees. I then put the site into minimal unattended mode and took a taxi to the hospital where they wired me up like a lab rat, inserted tubing as appropriate, and confined me for the night en Soins intensifs--which is kind of like sleeping in a video game parlour, except that the wrong kind of beep really means "Game Over".

At first, all the evidence pointed to an isolated incident precipitated by my life-long "extrasystole" arrhythmia, which manifests itself when I'm short on sleep and exhausted, which I certainly was at the time, probably compounded by high blood pressure, which an impending speech and rushing out the door to give same certainly exacerbated. So, having blown off the speaking engagement, swallowing pills for the aforementioned conditions, I was released from Intensive Care with a portable heart monitor to wear around my neck and encouraged to run up and down stairs and other activities to see if the condition repeated. How very much like debugging an operating system!

After about 8 hours wearing the monitor, the smoking gun appeared. This is your heart (the weirdness in the line at the bottom is the "extrasystole"). This is your heart on ventricular tachycardia. Note that at the bottom right of the latter image the "watchdog timer" kicked in and reset the heartbeat to normal (which you can see extending to the right of the zoomed box).

There are many things which can cause this, but the way to bet, at least for somebody my age, is a constriction in a coronary artery (in other words, "walking heart attack time bomb") which obstructs blood flow to the heart's internal pacemaker, provoking the irregular heartbeat. These days, one investigates and deals with such a problem with angioplasty, for which I was sent to Inselspital Bern, where a tube was inserted in my femoral artery, through which a probe was directed up, around the aorta ("aorta make it straighter, so it's easier to navigate!"), and down into the coronary arteries, where a 75% blockage was found just before the branching off of the artery on the right side which feeds the internal pacemaker. You're wide awake while all this is going on, and can watch the whole thing in real time on television--cool--"straight from the heart!"

Having found the blockage, a balloon was sent into the nearly blocked artery which, after inflation, seems to have entirely opened it, so there was no need to insert a "stent" to hold it open. In three months we repeat the procedure to fix another minor blockage on the other side of the heart, at which time there's an opportunity to check on the first one and insert the stent if it's closing up. (In about 80% of the cases this isn't necessary, but you never know.) The good news is that these appear to be isolated incidents, not indicative of general problems.

In any case, I feel just fine; the entire procedure took a little more than an hour and involved less pain than a typical dental filling. As you may have gathered from my other scribblings, I do not obsess on health and, absent surprises, this is probably the last you'll read of this topic here. Having nothing else to do, I read lots of books in the last week, which I've only been able to add to the reading list and this chronicle in the last 24 hours. I've back-dated the reading list entries here so they don't prematurely scroll off the list; in the reading list proper, they are entered with the date I completed them, as usual.

Posted at 00:22 Permalink

Monday, May 23, 2005

Reading List: The Case for Democracy

Sharansky, Natan with Ron Dermer. The Case for Democracy. New York: PublicAffairs, 2004. ISBN 1-58648-261-0.
Every now and then you come across a book which cuts through the fog of contemporary political discourse with pure clarity of thought. Well of course, the programmer peanut gallery shouts in unison, Sharansky was a computer scientist before becoming a Soviet dissident and political prisoner, then Israeli politician! In this book Sharansky draws a line of unambiguous binary distinction between "free societies" and "fear societies". In a free society, you can walk into the town square and express your views without fear of arrest, imprisonment, or physical harm (p. 41); in a "fear society", you can't--it's that simple. Note that, as Sharansky is quick to observe, this counts as free societies without a trace of democracy, with dirigiste economies, and which discriminate against minorities and women--yet permit those who live there to protest these and other shortcomings without fear of recrimination. A society which he deems "free" may not be just, but a society which doesn't pass this most basic test of freedom is always unjust.

From this viewpoint, every compromise with fear societies and their tyrants in the interest of "stability" and "geopolitics" is always ill-considered, not just in terms of the human rights of those who live there, but in the self-interest of all free people. Fear societies require an enemy, internal or external, to unite their victims behind the tyrant, and history shows how fickle the affections of dictators can be when self-interest is at stake.

The disastrous example of funding Arafat's ugly dictatorship over the Palestinian people is dissected in detail, but the message is applicable everywhere diplomats argue for a "stable partner" over the inherent human right of people to own their own lives and govern themselves. Sharansky is forthright in saying it's better to face a democratically elected fanatic opponent than a dictator "we can do business with", because ultimately the democratic regime will converge on meeting the needs of its citizens, while the dictator will focus on feathering his own nest at the expense of those he exploits.

If you're puzzled about which side to back in all the myriad conflicts around the globe, you could do a lot worse that simply picking the side which comes out best in Sharansky's "town square test". Certainly, the world would be a better place if the diplomats who prattle on about "complexity" and realpolitik were hit over the head with the wisdom of an author who spent 13 years in Siberian labour camps rather than compromise his liberty.

Posted at 23:58 Permalink

Sunday, May 22, 2005

Reading List: Taboo

Entine, Jon. Taboo. New York: PublicAffairs, 2000. ISBN 1-58648-026-X.

A certain segment of the dogma-based community of postmodern academics and their hangers-on seems to have no difficulty whatsoever believing that Darwinian evolution explains every aspect of the origin and diversification of life on Earth while, at the same time, denying that genetics--the mechanism which underlies evolution--plays any part in differentiating groups of humans. Doublethink is easy if you never think at all. Among those to whom evidence matters, here's a pretty astonishing fact to ponder. In the last four Olympic games prior to the publication of this book in the year 2000, there were thirty-two finalists in the men's 100-metre sprint. All thirty-two were of West African descent--a region which accounts for just 8% of the world's population. If finalists in this event were randomly chosen from the entire global population, the probability of this concentration occurring by chance is 0.0832 or about 8×10-36, which is significant at the level of more than twelve standard deviations. The hardest of results in the flintiest of sciences--null tests of conservation laws and the like--are rarely significant above 7 to 8 standard deviations.

Now one can certainly imagine any number of cultural and other non-genetic factors which predispose those with West African ancestry toward world-class performance in sprinting, but twelve standard deviations? The fact that running is something all humans do without being taught, and that training for running doesn't require any complicated or expensive equipment (as opposed to sports such as swimming, high-diving, rowing, or equestrian events), and that champions of West African ancestry hail from countries around the world, should suggest a genetic component to all but the most blinkered of blank slaters.

Taboo explores the reality of racial differences in performance in various sports, and the long and often sordid entangled histories of race and sports, including the tawdry story of race science and eugenics, over-reaction to which has made most discussion of human biodiversity, as the title of book says, taboo. The equally forbidden subject of inherent differences in male and female athletic performance is delved into as well, with a look at the hormone dripping "babes from Berlin" manufactured by the cruel and exploitive East German sports machine before the collapse of that dismal and unlamented tyranny.

Those who know some statistics will have no difficulty understanding what's going on here--the graph on page 255 tells the whole story. I wish the book had gone into a little more depth about the phenomenon of a slight shift in the mean performance of a group--much smaller than individual variation--causing a huge difference in the number of group members found in the extreme tail of a normal distribution. Another valuable, albeit speculative, insight is that if one supposes that there are genes which confer advantage to competitors in certain athletic events, then given the intense winnowing process world-class athletes pass through before they reach the starting line at the Olympics, it is plausible all of them at that level possess every favourable gene, and that the winner is determined by training, will to win, strategy, individual differences, and luck, just as one assumed before genetics got mixed up in the matter. It's just that if you don't have the genes (just as if your legs aren't long enough to be a runner), you don't get anywhere near that level of competition.

Unless research in these areas is suppressed due to an ill-considered political agenda, it is likely that the key genetic components of athletic performance will be identified in the next couple of decades. Will this mean that world-class athletic competition can be replaced by DNA tests? Of course not--it's just that one factor in the feedback loop of genetic endowment, cultural reinforcement of activities in which group members excel, and the individual striving for excellence which makes competitors into champions will be better understood.

Posted at 11:38 Permalink

Saturday, May 21, 2005

Reading List: Brotherhood of the Bomb

Herken. Gregg. Brotherhood of the Bomb. New York: Henry Holt, 2002. ISBN 0-8050-6589-X.
What more's to be said about the tangled threads of science, politics, ego, power, and history that bound together the lives of Ernest O. Lawrence, J. Robert Oppenheimer, and Edward Teller from the origin of the Manhattan Project through the postwar controversies over nuclear policy and the development of thermonuclear weapons? In fact, a great deal, as declassification of FBI files, including wiretap transcripts, release of decrypted Venona intercepts of Soviet espionage cable traffic, and documents from Moscow archives opened to researchers since the collapse of the Soviet Union have provide a wealth of original source material illuminating previously dark corners of the epoch.

Gregg Herken, a senior historian and curator at the National Air and Space Museum, draws upon these resources to explore the accomplishments, conflicts, and controversies surrounding Lawrence, Oppenheimer, and Teller, and the cold war era they played such a large part in defining. The focus is almost entirely on the period in which the three were active in weapons development and policy--there is little discussion of their prior scientific work, nor of Teller's subsequent decades on the public stage. This is a serious academic history, with almost 100 pages of source citations and bibliography, but the story is presented in an engaging manner which leaves the reader with a sense of the personalities involved, not just their views and actions. The author writes with no discernible ideological bias, and I noted only one insignificant technical goof.

Posted at 15:24 Permalink

Friday, May 20, 2005

Reading List: Tom Swift and His Motor-Boat

Appleton, Victor. Tom Swift and His Motor-Boat. McLean, VA: IndyPublish.com, [1910] 2005. ISBN 1-414-24253-0.
This is the second installment in the Tom Swift saga. These early volumes are more in the genre of juvenile adventure than the science fiction which emerges later in the series. I read the electronic edition of this novel published in the Tom Swift and His Pocket Library collection at this site on my PalmOS PDA. I've posted an updated electronic edition which corrects typographical and formatting errors I noted in reading the novel.

Posted at 14:15 Permalink

Wednesday, May 11, 2005

Reading List: The Black Arrow

Suprynowicz, Vin. The Black Arrow. Las Vegas: Mountain Media, 2005. ISBN 0-9762516-0-4.
For more than a decade, Vin Suprynowicz's columns in the Las Vegas Review-Journal (collected in Send In The Waco Killers and The Ballad of Carl Drega) have chronicled the closing circle of individual freedom in the United States. You may find these books difficult to finish, not due to any fault in the writing, which is superb, but because reading of the treatment of citizens at the hands of a government as ignorant as it is imperious makes your blood boil. Here, however, in his first venture into fiction, the author has written a book which is difficult to put down.

The year is 2030, and every complacent person who asked rhetorically, "How much worse can it get?" has seen the question answered beyond their worst nightmares. What's left of the United States is fighting to put down the secessionist mountain states of New Columbia, and in the cities of the East, people are subject to random searches by jackbooted Lightning Squads, when they aren't shooting up clandestine nursery schools operated by anarchist parents who refuse to deliver their children into government indoctrination. This is the kind of situation which cries out for a superhero and, lo and behold, onto the stage steps The Black Arrow and his deadly serious but fun-loving band to set things right through the time-tested strategy of killing the bastards. The Black Arrow has a lot in common with Batman--actually maybe a tad too much. Like Batman, he's a rich and resourceful man with a mission (but no super powers), he operates in New York City, which is called "Gotham" in the novel, and he has a secret lair in a cavern deep beneath the city.

There is a modicum of libertarian background and philosophy, but it never gets in the way of the story. There is enough explicit violence and copulation for an R rated movie--kids and those with fragile sensibilities should give this one a miss. Some of the verbal imagery in the story is so vivid you can almost see it erupting from the page--this would make a tremendous comic book adaptation or screenplay for an alternative universe Hollywood where stories of liberty were welcome.

Posted at 22:18 Permalink

Saturday, May 7, 2005

Reading List: No Free Lunch

Dembski, William A. No Free Lunch. Lanham, MD: Rowan & Littlefield, 2002. ISBN 0-7425-1297-5.
It seems to be the rule that the softer the science, the more rigid and vociferously enforced the dogma. Physicists, confident of what they do know and cognisant of how much they still don't, have no problems with speculative theories of parallel universes, wormholes and time machines, and inconstant physical constants. But express the slightest scepticism about Darwinian evolution being the one, completely correct, absolutely established beyond a shadow of a doubt, comprehensive and exclusive explanation for the emergence of complexity and diversity in life on Earth, and outraged biologists run to the courts, the legislature, and the media to suppress the heresy, accusing those who dare to doubt their dogma as being benighted opponents of science seeking to impose a "theocracy". Funny, I thought science progressed by putting theories to the test, and that all theories were provisional, subject to falsification by experimental evidence or replacement by a more comprehensive theory which explains additional phenomena and/or requires fewer arbitrary assumptions.

In this book, mathematician and philosopher William A. Dembski attempts to lay the mathematical and logical foundation for inferring the presence of intelligent design in biology. Note that "intelligent design" needn't imply divine or supernatural intervention--the "directed panspermia" theory of the origin of life proposed by co-discoverer of the structure of DNA and Nobel Prize winner Francis Crick is a theory of intelligent design which invokes no deity, and my perpetually unfinished work The Rube Goldberg Variations and the science fiction story upon which it is based involve searches for evidence of design in scientific data, not in scripture.

You certainly won't find any theology here. What you will find is logical and mathematical arguments which sometimes ascend (or descend, if you wish) into prose like (p. 153), "Thus, if P characterizes the probability of E0 occurring and f characterizes the physical process that led from E0 to E1, then Pf -1 characterizes the probability of E1 occurring and P(E0) ≤ Pf -1(E1) since f(E0) = E1 and thus E0 ⊂ f -1(E1)." OK, I did cherry-pick that sentence from a particularly technical section which the author advises readers to skip if they're willing to accept the less formal argument already presented. Technical arguments are well-supplemented by analogies and examples throughout the text.

Dembski argues that what he terms "complex specified information" is conclusive evidence for the presence of design. Complexity (the Shannon information measure) is insufficient--all possible outcomes of flipping a coin 100 times in a row are equally probable--but presented with a sequence of all heads, all tails, alternating heads and tails, or a pattern in which heads occurred only for prime numbered flips, the evidence for design (in this case, cheating or an unfair coin) would be considered overwhelming. Complex information is considered specified if it is compressible in the sense of Chaitin-Kolmogorov-Solomonoff algorithmic information theory, which measures the randomness of a bit string by the length of the shortest computer program which could produce it. The overwhelming majority of 100 bit strings cannot be expressed more compactly than simply by listing the bits; the examples given above, however, are all highly compressible. This is the kind of measure, albeit not rigorously computed, which SETI researchers would use to identify a signal as of intelligent origin, which courts apply in intellectual property cases to decide whether similarity is accidental or deliberate copying, and archaeologists use to determine whether an artefact is of natural or human origin. Only when one starts asking these kinds of questions about biology and the origin of life does controversy erupt!

Chapter 3 proposes a "Law of Conservation of Information" which, if you accept it, would appear to rule out the generation of additional complex specified information by the process of Darwinian evolution. This would mean that while evolution can and does account for the development of resistance to antibiotics in bacteria and pesticides in insects, modification of colouration and pattern due to changes in environment, and all the other well-confirmed cases of the Darwinian mechanism, that innovation of entirely novel and irreducibly complex (see chapter 5) mechanisms such as the bacterial flagellum require some external input of the complex specified information they embody. Well, maybe . . . but one should remember that conservation laws in science, unlike invariants in mathematics, are empirical observations which can be falsified by a single counter-example. Niels Bohr, for example, prior to its explanation due to the neutrino, theorised that the energy spectrum of nuclear beta decay could be due to a violation of conservation of energy, and his theory was taken seriously until ruled out by experiment.

Let's suppose, for the sake of argument, that Darwinian evolution does explain the emergence of all the complexity of the Earth's biosphere, starting with a single primordial replicating lifeform. Then one still must explain how that replicator came to be in the first place (since Darwinian evolution cannot work on non-replicating organisms), and where the information embodied in its molecular structure came from. The smallest present-day bacterial genomes belong to symbiotic or parasitic species, and are in the neighbourhood of 500,000 base pairs, or roughly 1 megabit of information. Even granting that the ancestral organism might have been much smaller and simpler, it is difficult to imagine a replicator capable of Darwinian evolution with an information content 1000 times smaller than these bacteria, Yet randomly assembling even 500 bits of precisely specified information seems to be beyond the capacity of the universe we inhabit. If you imagine every one of the approximately 1080 elementary particles in the universe trying combinations every Planck interval, 1045 times every second, it would still take about a billion times the present age of the universe to randomly discover a 500 bit pattern. Of course, there are doubtless many patterns which would work, but when you consider how conservative all the assumptions are which go into this estimate, and reflect upon the evidence that life seemed to appear on Earth just about as early as environmental conditions permitted it to exist, it's pretty clear that glib claims that evolution explains everything and there are just a few details to be sorted out are arm-waving at best and propaganda at worst, and that it's far too early to exclude any plausible theory which could explain the mystery of the origin of life. Although there are many points in this book with which you may take issue, and it does not claim in any way to provide answers, it is valuable in understanding just how difficult the problem is and how many holes exist in other, more accepted, explanations. A clear challenge posed to purely naturalistic explanations of the origin of terrestrial life is to suggest a prebiotic mechanism which can assemble adequate specified information (say, 500 bits as the absolute minimum) to serve as a primordial replicator from the materials available on the early Earth in the time between the final catastrophic bombardment and the first evidence for early life.

Posted at 22:49 Permalink

Friday, May 6, 2005

ETSET Version 3.1 Posted

I've just posted version 3.1 of ETSET, the utility which translates electronic texts written in human readable form into LaTeX (and thence to PostScript and PDF, if you wish), HTML (either single document or individual chapters with navigation links), or Palm Markup Language (PML) to produce eReader books which can be read on a variety of PDA and smart mobile telephone platforms. ETSET is used to produce most of the electronic texts available at this site, including the Tom Swift and His Pocket Library collection.

Version 3.1, the first update since version 3.0.1 in September 2001, is 100% compatible with that version in input syntax and command line options. When HTML output is selected, version 3.1 generates XHTML 1.0 (Transitional DTD) which should validate without errors or warnings when checked by the W3C Markup and CSS Validation Services. Navigation button images for multiple file HTML documents have been changed from GIF to PNG files.

In addition to the substantive changes, the usual collection of daggers in the back from the GCC/C++ priesthood have been extracted; the program now compiles without warnings at the -Wall level on GCC 3.4.3. The Win32 executable is now built with Microsoft Visual C++.NET instead of the DOS extender DJgpp compiler used previously; the resulting program is a native Win32 console application. ETSET is a C++/STL program written using the Literate Programming methodology in the CWEB System; the source code and complete documentation (both user-level and internal) may be read online (PDF file).

Posted at 21:44 Permalink

Wednesday, May 4, 2005

Wright's Gadsby Available Online

In 1939, Ernest Vincent Wright published Gadsby, a novel of more than 50,000 words which never once uses the letter "e". This most curious volume has become somewhat of a collector's item--used copies on ABE and Amazon seem to start at around USD85 and go up from there.

Fortunately, an online edition is now available, including the author's delighful introduction (which does use the letter "e") which explains his strong construction of the constraint, which caused him to reject abbreviations such as "Mr." and "Mrs." which would, if expanded or spoken, use the letter "e". The fact that most past tenses in English end in "-ed" is particularly challenging, as well as the fact that every numeral greater than six and less than thirty is excluded, as well as most common pronouns.

And, of course, the story must end with "Finis" coronat opus, as "The End" is doubly right out!

Posted at 00:10 Permalink

Sunday, May 1, 2005

Seeing Ceres

Most people, even those who've dreamt of or even hoped for a life of liberty and adventure in the asteroid belt, have never actually seen an asteroid with their own eyes. If you, as I, wish to remedy this observational lacuna, the first week of May this year will provide an excellent opportunity to spot the first-discovered and largest asteroid.

Asteroid 1 Ceres is at opposition on the 8th of May and hence is visible all night. But more importantly, between the 1st and 7th of May it passes close to the bright (magnitude 2.6) star Beta Libræ (Zubeneshamali), the top of the almost perfect right triangle formed by Alpha, Beta, and Gamma Libræ in the southeastern sky as seen from temperate latitudes in the northern hemisphere around 23:00 local summer time. Ceres will be about magnitude 7.0 this week, which is right on the edge of naked eye visibility under perfectly dark and transparent skies (which, sadly, few of us enjoy), but it's an easy object with even the most modest of binoculars, which will show Ceres and Beta Libræ in the same field. Ceres will be above (toward the zenith) and to the left of Beta Libræ on May 1, moving off to the right after May 4. The following link will show Ceres in the southeastern sky from a viewpoint around the middle of the U.S. at 05:00 UTC on May 3. You can adjust the viewpoint, date, and time as you like in the boxes below the image, or click in the image to show a telescope/binocular view into which you can zoom. The grey disc with the red "A" is the asteroid Ceres--pretty spiffy graphics, don't you think?

Ceres in the southeastern sky
The orbital position calculations and image generation are done by the Fourmilab Your Sky server. If you wish to generate a custom image, remember that the date and time are specified in Universal time, and you need to take into account not only the time zone difference but the fact that Universal time does not include the summer time offset.

The following link will show where Ceres is with respect to the planets of the inner Solar System at the time it is clicked:

Ceres: Orrery View
generated by Solar System Live.

If you have more than one pair of binoculars, you can invite the neighbours to spot their first asteroid along with you--a laser pointer is great for indicating where to look in the sky. Then you can say that you've spotted Ceres in parallel!

Posted at 17:57 Permalink