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Tuesday, January 31, 2017

Bending Spacetime in the Basement: HTML5 Update

Bending Spacetime in the Basement was one of the first “basement science” experiments posted on Fourmilab. It shows how to demonstrate universal gravitation on the human scale with simple apparatus and speculates on how Archimedes might have discovered universal gravitation 1900 years before Newton.

This page was originally posted in July of 1997, and was showing its age. I have just posted a 2017 update, which uses HTML5 to provide improved typography and embed videos of the experiments within the page.

This is a demanding experiment. Some people have managed to reproduce it, while others have run into difficulties. You need a location with a stable temperature, free of drafts, which is far from walls or other massive structures. You'll need to be patient to wait for the stresses in the support fibre to be released. It took me about two months to sort out all of the disturbing influences and obtain the reliable results presented here. It is, thus, not an ideal project to introduce school classes to experimental science unless the goal is to demonstrate how frustrating an endeavour it can be. (That said, some teachers have managed to get this experiment to work for their classes, who much appreciated it,)

Posted at 01:00 Permalink

Sunday, January 29, 2017

Orbits in Strongly Curved Spacetime: HTML5 Update

Since February 1997, Orbits in Strongly Curved Spacetime has allowed visitors to explore the wildly non-Keplerian orbits of a test mass in the vicinity of a compact gravitating body such as a neutron star or black hole. This was accomplished through an animation which plots the orbit and shows the motion of the particle in the gravitational effective potential and gravity well surrounding the object. The animation was implemented as a Java applet, which, as I have noted earlier here, fewer and fewer browsers support.

I have just posted an updated version which uses HTML5/JavaScript animation instead of Java, and should run on all modern browsers, including mobile devices, which support these standards. The original Java version remains available.

Posted at 20:23 Permalink

Friday, January 27, 2017

Retropsychokinesis Project: Twentieth Anniversary Update

The Retropsychokinesis Project (RPKP) celebrates its twentieth anniversary this month. Launched in January of 1997, the project may be the largest and longest-running parapsychology experiment in history, having recorded over 880,000 experiments performed by more than 34,000 volunteers around the globe. (Participants can designate experiments as “practice” or “for the record”. The total above includes both categories, while the Experiment Summary, updated daily, includes only for the record experiments, which currently number more than 380,000.) In addition, control runs are automatically run and reported daily: almost 150,000 control runs are in the database.

Retropsychokinesis tests the hypothesis that users are able to exert an influence upon random data which have been pre-recorded but not examined prior to their experimental runs, and that the statistics of these data will differ from those of unexamined data. Please see the Background to the experiments for additional details, the retrocausality bibliography for additional reading, or the main project page for further references, some of which are online. “But that's crazy!”, you exclaim. Yes, I know, but previous experiments, notably those conducted by the physicist and parapsychologist Helmut Schmidt, have suggested that such an effect, albeit very small, may exist. I have proposed the outline of a crackpot theory which might explain such seemingly impossible experimental results.

The great advantage of experimenting with retropsychokinesis is that most of the problems which plague investigations of other claims of paranormal phenomena do not occur. Data are pre-recorded before the user examines and attempts to influence them. There is no opportunity for fraud by modifying the experimental data, nor by reporting only successful experimental runs. Random data are generated by the Fourmilab HotBits radioactive random number generator, which has been in operation for more than twenty years and passed all statistical tests of randomness. The data collected by the RPKP are completely transparent, and the complete database of experiment and control runs, updated daily, may be downloaded by anybody with access to the Internet. Individuals who participate in the project by running experiments may consult a list of their experiments and results, updated in real time. A number of other resources are available, including an introduction to probability and statistics and statistical analysis tools, all accessible from the RPKP experiments Table of Contents.

The RPKP experiments deliver a stream of 1024 random bits to the user, who then attempts to influence them as they are presented via a visual feedback program, with a statistical report of the result at the end. The visual feedback programs were originally written as Java applets, which were the going thing in the 1990s when the project was launched, and the only game in town at the time for providing interactive animation in Web pages. Unfortunately, the “write once, run anywhere” promise of Java now deservedly receives the rejoinder, “yeah, right”, and two decades of incompatibilities, security flaws, and browser integration problems have brought Java, at least for Web page applets, to the brink of being pitched into the dustbin of computer history—sad.

The end of Java has made the RPKP experiments less accessible to users, and reduced the rate at which experiments are run. Fortunately, there is now an alternate to Java, HTML5 canvas animations with JavaScript (which, despite the name, has nothing whatsoever to do with the Java language): Web standards implemented in all modern browsers, including those on mobile devices, which require no third-party plug-ins to be installed by users.

The Twentieth Anniversary Update of the Retropsychokinesis Project implements all of the visual feedback programs in HTML5/JavaScript, rendering them accessible to anybody with a modern browser. (The Java applet versions of the programs remain available for users with older browsers, or who do not wish to change to the new versions.) There is no change in the functionality of the experiments; the results recorded do not depend upon which version of the visual feedback programs are selected. As has been the case with the RPKP since inception, all of the source code of these programs is transparent and may be downloaded, and users are free to create their own visual feedback programs submit them for inclusion in the Project.

So what about the results? I don't comment on that. I collect the data and publish a daily statistical analysis of the aggregated data. I leave to individual investigators the analysis of the database and formulation and testing of hypotheses based upon the experiments it records.

This update should dramatically increase the number of users who can run RPKP experiments, as the struggle to download, install, enable, and incessantly update Java is no longer a prerequisite. I hope this will contribute to the continued growth of the RPKP database and its value to investigators as the project enters its third decade.

Meanwhile, try running some experiments yourself!

Posted at 00:04 Permalink

Friday, January 20, 2017

Comparing Cabinets and Classes: Harding, Obama, and Trump

In his 1922 book, American Individualism, Herbert Hoover, then Secretary of Commerce in the Harding administration, wrote of his cabinet colleagues:

That our system has avoided the establishment and domination of class has a significant proof in the present Administration in Washington, Of the twelve men comprising the President, Vice-President, and Cabinet, nine have earned their own way in life without economic inheritance, and eight of them started with manual labor.

In my December 2016 review of Hoover's book, I compared the cabinet in which Hoover served with the Obama cabinet at the time as follows.

Let's see how that has held up, almost a century later. Taking the 17 people in equivalent positions at the end of the Obama administration in 2016 (President, Vice President, and heads of the 15 executive departments), we find that only 1 of the 17 inherited wealth (I'm inferring from the description of parents in their biographies) but that precisely zero had any experience with manual labour. If attending an Ivy League university can be taken as a modern badge of membership in a ruling class, 11 of the 17—65%, meet this test (if you consider Stanford a member of an "extended Ivy League", the figure rises to 70%).

Now that all appointments to the Trump cabinet have been made, and on the assumption all will be confirmed, how will that group compare by Hoover's standard?

Again, we have a total of 17 people: President, Vice President, and heads of the 15 executive departments. As before, I infer inheritance from the description of an appointee's parents and early life; if a parent is described as a “billionaire” and their child attended a private school, I put them down as having inherited wealth. Enlisted military service or membership in a special operations unit was deemed manual labour. Either an undergraduate or graduate degree from an Ivy counted. The results are:

Compared to the Obama cabinet, there is more inherited wealth (one of these is, of course, the President), more with experience with manual labour, and fewer with an Ivy League background. This is still a much more élite group than Harding's cabinet.

Posted at 16:15 Permalink

Thursday, January 19, 2017

Probability Pipe Organ Updated to HTML5

Twenty years ago I posted The Probability Pipe Organ as part of the “Introduction to Probability and Statistics” documenting the Retropsychokinesis Experiments Online (RPKP). The pipe organ illustrates how the results of a series of experiments involving random values approaches the binomal distribution as the number of experiments increases.

This page was original implemented as a Java applet. When the Java language was launched, the accompanying hype claimed “Write once. Run everywhere.” After experience with several implementations of Java on different platforms, I added “Yeah, right.” to the slogan. Still, at the time, Java was the only practical way to include complex interaction and simulation in Web pages, so I used it for the pipe organ and online RPKP experiments.

In subsequent years, Java suffered severe bloat of the language and standard libraries, which created a security perimeter so large that when Java was embedded within a Web browser, it presented substantial security risks, to such an extent that many modern browsers disable Java by default, and, if they support it, require the user to manually install it and keep it up to date. This poses a barrier to what were intended to be easily-accessible Web resources.

While there is much to dislike about HTML5, its canvas element and multimedia support, along with JavaScript, allow interaction and animation within standards-compliant documents without third-party browser add-ons. I am in the process of replacing all Java applets on the Fourmilab site with HTML5; the probability pipe organ is the pathfinder for this project.

The HTML5 version is now the default. Users with older browsers, or those with Java installed who wish to compare, can still access the original Java implementation.

Posted at 12:37 Permalink

Monday, January 16, 2017

Reading List: The Kingdom of Speech

Wolfe, Tom. The Kingdom of Speech. New York: Little, Brown, 2016. ISBN 978-0-316-40462-4.
In this short (192) page book, Tom Wolfe returns to his roots in the “new journalism”, of which he was a pioneer in the 1960s. Here the topic is the theory of evolution; the challenge posed to it by human speech (because no obvious precursor to speech occurs in other animals); attempts, from Darwin to Noam Chomsky to explain this apparent discrepancy and preserve the status of evolution as a “theory of everything”; and the evidence collected by linguist and anthropologist Daniel Everett among the Pirahã people of the Amazon basin in Brazil, which appears to falsify Chomsky's lifetime of work on the origin of human language and the universality of its structure. A second theme is contrasting theorists and intellectuals such as Darwin and Chomsky with “flycatchers” such as Alfred Russel Wallace, Darwin's rival for priority in publishing the theory of evolution, and Daniel Everett, who work in the field—often in remote, unpleasant, and dangerous conditions—to collect the data upon which the grand thinkers erect their castles of hypothesis.

Doubtless fearful of the reaction if he suggested the theory of evolution applied to the origin of humans, in his 1859 book On the Origin of Species, Darwin only tiptoed close to the question two pages from the end, writing, “In the distant future, I see open fields for far more important researches. Psychology will be securely based on a new foundation, that of the necessary acquirement of each mental power and capacity of gradation. Light will be thrown on the origin of man and his history.” He needn't have been so cautious: he fooled nobody. The very first review, five days before publication, asked, “If a monkey has become a man—…?”, and the tempest was soon at full force.

Darwin's critics, among them Max Müller, German-born professor of languages at Oxford, and Darwin's rival Alfred Wallace, seized upon human characteristics which had no obvious precursors in the animals from which man was supposed to have descended: a hairless body, the capacity for abstract thought, and, Müller's emphasis, speech. As Müller said, “Language is our Rubicon, and no brute will dare cross it.” How could Darwin's theory, which claimed to describe evolution from existing characteristics in ancestor species, explain completely novel properties which animals lacked?

Darwin responded with his 1871 The Descent of Man, and Selection in Relation to Sex, which explicitly argued that there were precursors to these supposedly novel human characteristics among animals, and that, for example, human speech was foreshadowed by the mating songs of birds. Sexual selection was suggested as the mechanism by which humans lost their hair, and the roots of a number of human emotions and even religious devotion could be found in the behaviour of dogs. Many found these arguments, presented without any concrete evidence, unpersuasive. The question of the origin of language had become so controversial and toxic that a year later, the Philological Society of London announced it would no longer accept papers on the subject.

With the rediscovery of Gregor Mendel's work on genetics and subsequent research in the field, a mechanism which could explain Darwin's evolution was in hand, and the theory became widely accepted, with the few discrepancies set aside (as had the Philological Society) as things we weren't yet ready to figure out.

In the years after World War II, the social sciences became afflicted by a case of “physics envy”. The contribution to the war effort by their colleagues in the hard sciences in areas such as radar, atomic energy, and aeronautics had been handsomely rewarded by prestige and funding, while the more squishy sciences remained in a prewar languor along with the departments of Latin, Medieval History, and Drama. Clearly, what was needed was for these fields to adopt a theoretical approach grounded in mathematics which had served so well for chemists, physicists, engineers, and appeared to be working for the new breed of economists.

It was into this environment that in the late 1950s a young linguist named Noam Chomsky burst onto the scene. Over its century and a half of history, much of the work of linguistics had been cataloguing and studying the thousands of languages spoken by people around the world, much as entomologists and botanists (or, in the pejorative term of Darwin's age, flycatchers) travelled to distant lands to discover the diversity of nature and try to make sense of how it was all interrelated. In his 1957 book, Syntactic Structures, Chomsky, then just twenty-eight years old and working in the building at MIT where radar had been developed during the war, said all of this tedious and messy field work was unnecessary. Humans had evolved (note, “evolved”) a “language organ”, an actual physical structure within the brain—the “language acquisition device”—which children used to learn and speak the language they heard from their parents. All human languages shared a “universal grammar”, on top of which all the details of specific languages so carefully catalogued in the field were just fluff, like the specific shape and colour of butterflies' wings. Chomsky invented the “Martian linguist” which was to come to feature in his lectures, who he claimed, arriving on Earth, would quickly discover the unity underlying all human languages. No longer need the linguist leave his air conditioned office. As Wolfe writes in chapter 4, “Now, all the new, Higher Things in a linguist's life were to be found indoors, at a desk…looking at learned journals filled with cramped type instead of at a bunch of hambone faces in a cloud of gnats.”

Given the alternatives, most linguists opted for the office, and for the prestige that a theory-based approach to their field conferred, and by the 1960s, Chomsky's views had taken over linguistics, with only a few dissenters, at whom Chomsky hurled thunderbolts from his perch on academic Olympus. He transmuted into a general-purpose intellectual, pronouncing on politics, economics, philosophy, history, and whatever occupied his fancy, all with the confidence and certainty he brought to linguistics. Those who dissented he denounced as “frauds”, “liars”, or “charlatans”, including B. F. Skinner, Alan Dershowitz, Jacques Lacan, Elie Wiesel, Christopher Hitchens, and Jacques Derrida. (Well, maybe I agree when it comes to Derrida and Lacan.) In 2002, with two colleagues, he published a new theory claiming that recursion—embedding one thought within another—was a universal property of human language and component of the universal grammar hard-wired into the brain.

Since 1977, Daniel Everett had been living with and studying the Pirahã in Brazil, originally as a missionary and later as an academic linguist trained and working in the Chomsky tradition. He was the first person to successfully learn the Pirahã language, and documented it in publications. In 2005 he published a paper in which he concluded that the language, one of the simplest ever described, contained no recursion whatsoever. It also contained neither a past nor future tense, description of relations beyond parents and siblings, gender, numbers, and many additional aspects of other languages. But the absence of recursion falsified Chomsky's theory, which pronounced it a fundamental part of all human languages. Here was a field worker, a flycatcher, braving not only gnats but anacondas, caimans, and just about every tropical disease in the catalogue, knocking the foundation from beneath the great man's fairy castle of theory. Naturally, Chomsky and his acolytes responded with their customary vituperation, (this time, the adjective of choice for Everett was “charlatan”). Just as they were preparing the academic paper which would drive a stake through this nonsense, Everett published Don't Sleep, There Are Snakes, a combined account of his thirty years with the Pirahã and an analysis of their language. The book became a popular hit and won numerous awards. In 2012, Everett followed up with Language: The Cultural Tool, which rejects Chomsky's view of language as an innate and universal human property in favour of the view that it is one among a multitude of artifacts created by human societies as a tool, and necessarily reflects the characteristics of those societies. Chomsky now refuses to discuss Everett's work.

In the conclusion, Wolfe comes down on the side of Everett, and argues that the solution to the mystery of how speech evolved is that it didn't evolve at all. Speech is simply a tool which humans used their big brains to invent to help them accomplish their goals, just as they invented bows and arrows, canoes, and microprocessors. It doesn't make any more sense to ask how evolution produced speech than it does to suggest it produced any of those other artifacts not made by animals. He further suggests that the invention of speech proceeded from initial use of sounds as mnemonics for objects and concepts, then progressed to more complex grammatical structure, but I found little evidence in his argument to back the supposition, nor is this a necessary part of viewing speech as an invented artifact. Chomsky's grand theory, like most theories made up without grounding in empirical evidence, is failing both by being falsified on its fundamentals by the work of Everett and others, and also by the failure, despite half a century of progress in neurophysiology, to identify the “language organ” upon which it is based.

It's somewhat amusing to see soft science academics rush to Chomsky's defence, when he's arguing that language is biologically determined as opposed to being, as Everett contends, a social construct whose details depend upon the cultural context which created it. A hunter-gatherer society such as the Pirahã living in an environment where food is abundant and little changes over time scales from days to generations, doesn't need a language as complicated as those living in an agricultural society with division of labour, and it shouldn't be a surprise to find their language is more rudimentary. Chomsky assumed that all human languages were universal (able to express any concept), in the sense David Deutsch defined universality in The Beginning of Infinity, but why should every people have a universal language when some cultures get along just fine without universal number systems or alphabets? Doesn't it make a lot more sense to conclude that people settle on a language, like any other tools, which gets the job done? Wolfe then argues that the capacity of speech is the defining characteristic of human beings, and enables all of the other human capabilities and accomplishments which animals lack. I'd consider this not proved. Why isn't the definitive human characteristic the ability to make tools, and language simply one among a multitude of tools humans have invented?

This book strikes me as one or two interesting blog posts struggling to escape from a snarknado of Wolfe's 1960s style verbal fireworks, including Bango!, riiippp, OOOF!, and “a regular crotch crusher!”. At age 85, he's still got it, but I wonder whether he, or his editor, questioned whether this style of journalism is as effective when discussing evolutionary biology and linguistics as in mocking sixties radicals, hippies, or pretentious artists and architects. There is some odd typography, as well. Grave accents are used in words like “learnèd”, presumably to indicate it's to be pronounced as two syllables, but then occasionally we get an acute accent instead—what's that supposed to mean? Chapter endnotes are given as superscript letters while source citations are superscript numbers, neither of which are easy to select on a touch-screen Kindle edition. There is no index.

Posted at 01:48 Permalink

Friday, January 13, 2017

Reading List: Planck

Brown, Brandon R. Planck. Oxford: Oxford University Press, 2015. ISBN 978-0-19-021947-5.
Theoretical physics is usually a young person's game. Many of the greatest breakthroughs have been made by researchers in their twenties, just having mastered existing theories while remaining intellectually flexible and open to new ideas. Max Planck, born in 1858, was an exception to this rule. He spent most of his twenties living with his parents and despairing of finding a paid position in academia. He was thirty-six when he took on the project of understanding heat radiation, and forty-two when he explained it in terms which would launch the quantum revolution in physics. He was in his fifties when he discovered the zero-point energy of the vacuum, and remained engaged and active in science until shortly before his death in 1947 at the age of 89. As theoretical physics editor for the then most prestigious physics journal in the world, Annalen der Physik, in 1905 he approved publication of Einstein's special theory of relativity, embraced the new ideas from a young outsider with neither a Ph.D. nor an academic position, extended the theory in his own work in subsequent years, and was instrumental in persuading Einstein to come to Berlin, where he became a close friend.

Sometimes the simplest puzzles lead to the most profound of insights. At the end of the nineteenth century, the radiation emitted by heated bodies was such a conundrum. All objects emit electromagnetic radiation due to the thermal motion of their molecules. If an object is sufficiently hot, such as the filament of an incandescent lamp or the surface of the Sun, some of the radiation will fall into the visible range and be perceived as light. Cooler objects emit in the infrared or lower frequency bands and can be detected by instruments sensitive to them. The radiation emitted by a hot object has a characteristic spectrum (the distribution of energy by frequency), and has a peak which depends only upon the temperature of the body. One of the simplest cases is that of a black body, an ideal object which perfectly absorbs all incident radiation. Consider an ideal closed oven which loses no heat to the outside. When heated to a given temperature, its walls will absorb and re-emit radiation, with the spectrum depending upon its temperature. But the equipartition theorem, a cornerstone of statistical mechanics, predicted that the absorption and re-emission of radiation in the closed oven would result in a ever-increasing peak frequency and energy, diverging to infinite temperature, the so-called ultraviolet catastrophe. Not only did this violate the law of conservation of energy, it was an affront to common sense: closed ovens do not explode like nuclear bombs. And yet the theory which predicted this behaviour, the Rayleigh-Jeans law, made perfect sense based upon the motion of atoms and molecules, correctly predicted numerous physical phenomena, and was correct for thermal radiation at lower temperatures.

At the time Planck took up the problem of thermal radiation, experimenters in Germany were engaged in measuring the radiation emitted by hot objects with ever-increasing precision, confirming the discrepancy between theory and reality, and falsifying several attempts to explain the measurements. In December 1900, Planck presented his new theory of black body radiation and what is now called Planck's Law at a conference in Berlin. Written in modern notation, his formula for the energy emitted by a body of temperature T at frequency ν is:

Planck's Law

This equation not only correctly predicted the results measured in the laboratories, it avoided the ultraviolet catastrophe, as it predicted an absolute cutoff of the highest frequency radiation which could be emitted based upon an object's temperature. This meant that the absorption and re-emission of radiation in the closed oven could never run away to infinity because no energy could be emitted above the limit imposed by the temperature.

Fine: the theory explained the measurements. But what did it mean? More than a century later, we're still trying to figure that out.

Planck modeled the walls of the oven as a series of resonators, but unlike earlier theories in which each could emit energy at any frequency, he constrained them to produce discrete chunks of energy with a value determined by the frequency emitted. This had the result of imposing a limit on the frequency due to the available energy. While this assumption yielded the correct result, Planck, deeply steeped in the nineteenth century tradition of the continuum, did not initially suggest that energy was actually emitted in discrete packets, considering this aspect of his theory “a purely formal assumption.” Planck's 1900 paper generated little reaction: it was observed to fit the data, but the theory and its implications went over the heads of most physicists.

In 1905, in his capacity as editor of Annalen der Physik, he read and approved the publication of Einstein's paper on the photoelectric effect, which explained another physics puzzle by assuming that light was actually emitted in discrete bundles with an energy determined by its frequency. But Planck, whose equation manifested the same property, wasn't ready to go that far. As late as 1913, he wrote of Einstein, “That he might sometimes have overshot the target in his speculations, as for example in his light quantum hypothesis, should not be counted against him too much.” Only in the 1920s did Planck fully accept the implications of his work as embodied in the emerging quantum theory.

The equation for Planck's Law contained two new fundamental physical constants: Planck's constant (h) and Boltzmann's constant (kB). (Boltzmann's constant was named in memory of Ludwig Boltzmann, the pioneer of statistical mechanics, who committed suicide in 1906. The constant was first introduced by Planck in his theory of thermal radiation.) Planck realised that these new constants, which related the worlds of the very large and very small, together with other physical constants such as the speed of light (c), the gravitational constant (G), and the Coulomb constant (ke), allowed defining a system of units for quantities such as length, mass, time, electric charge, and temperature which were truly fundamental: derived from the properties of the universe we inhabit, and therefore comprehensible to intelligent beings anywhere in the universe. Most systems of measurement are derived from parochial anthropocentric quantities such as the temperature of somebody's armpit or the supposed distance from the north pole to the equator. Planck's natural units have no such dependencies, and when one does physics using them, equations become simpler and more comprehensible. The magnitudes of the Planck units are so far removed from the human scale they're unlikely to find any application outside theoretical physics (imagine speed limit signs expressed in a fraction of the speed of light, or road signs giving distances in Planck lengths of 1.62×10−35 metres), but they reflect the properties of the universe and may indicate the limits of our ability to understand it (for example, it may not be physically meaningful to speak of a distance smaller than the Planck length or an interval shorter than the Planck time [5.39×10−44 seconds]).

Planck's life was long and productive, and he enjoyed robust health (he continued his long hikes in the mountains into his eighties), but was marred by tragedy. His first wife, Marie, died of tuberculosis in 1909. He outlived four of his five children. His son Karl was killed in 1916 in World War I. His two daughters, Grete and Emma, both died in childbirth, in 1917 and 1919. His son and close companion Erwin, who survived capture and imprisonment by the French during World War I, was arrested and executed by the Nazis in 1945 for suspicion of involvement in the Stauffenberg plot to assassinate Hitler. (There is no evidence Erwin was a part of the conspiracy, but he was anti-Nazi and knew some of those involved in the plot.)

Planck was repulsed by the Nazis, especially after a private meeting with Hitler in 1933, but continued in his post as the head of the Kaiser Wilhelm Society until 1937. He considered himself a German patriot and never considered emigrating (and doubtless his being 75 years old when Hitler came to power was a consideration). He opposed and resisted the purging of Jews from German scientific institutions and the campaign against “Jewish science”, but when ordered to dismiss non-Aryan members of the Kaiser Wilhelm Society, he complied. When Heisenberg approached him for guidance, he said, “You have come to get my advice on political questions, but I am afraid I can no longer advise you. I see no hope of stopping the catastrophe that is about to engulf all our universities, indeed our whole country. … You simply cannot stop a landslide once it has started.”

Planck's house near Berlin was destroyed in an Allied bombing raid in February 1944, and with it a lifetime of his papers, photographs, and correspondence. (He and his second wife Marga had evacuated to Rogätz in 1943 to escape the raids.) As a result, historians have only limited primary sources from which to work, and the present book does an excellent job of recounting the life and science of a man whose work laid part of the foundations of twentieth century science.

Posted at 01:08 Permalink

Monday, January 9, 2017

The Autodesk File: Thirty-fifth Anniversary Edition

This year marks the thirty-fifth anniversary of several key events in the history of Autodesk: To celebrate Autodesk's thirty-fifth anniversary, I have prepared the the Fifth Edition (2017) of The Autodesk File. Except for correction of a few typographical errors, the content is identical to that of the 1994 fourth edition, but the book has been entirely reformatted and updated to contemporary Web standards. The typography uses Unicode text entities, and should be much easier on the eye. Each chapter is now a single document, instead of being broken into sections and subsections, and easier to read without incessant clicking on navigation buttons. All of the AutoCAD sample drawings used as illustrations have been re-made from their original PostScript plot files with higher resolution. The pop-up windows for footnotes (which were irritating and ran afoul of some browser pop-up blockers) have been replaced by [Footnote] icons which display the footnote when clicked. Cross-references are indicated by an [Ref] icon which navigates to the cited page when clicked. A navigation bar at the left provides instant access to all chapters, and highlights the current chapter regardless of how you arrived there. The Fifth Edition is compatible with most modern desktop browsers. The Safari browser on iOS mobile devices (iPad, iPhone) has a serious flaw in scrolling text within a window which has remained uncorrected for years. On these devices, you can read the iOS work-around edition, which contains a device-specific fix for the problem. All previous Web editions of the book remain available from its main directory page.

Posted at 21:31 Permalink