7 August 2022
- Replaced all the GIFs in Ptolemy's Table of Chords with HTML and SVG. No more pixelated text or diagrams. Also added a postscript where I checked every value in Ptolemy's table using Google Sheets. The root-mean-square error is ±0.000136° (absolute) and ±7.37 ppm (relative). The relative error is the one more useful to us today as we no longer assume a diameter divided up into 120° like they did in 2nd century Alexandria. (We still do divide the central angles of a circle into 360°, however. That bit of ancient geometry may never go away.)
30 August 2016
- Site redesign using HTML5 and CSS3. It's what all the cool kids are doing.
- Changed URLs all over the place to make it easier to code pages. This is mostly driven by my love of server side includes. Added plenty of redirects to the .htaccess file, so there shouldn't be any problems with 404 errors. No link rot here.
- Deleted pages that I no longer wish to be associated with or am too lazy to update.
- Added Open Graph and Schema metadata to improve the way pages are displayed on social media and search engines. Trying to make Twitter Cards work too.
- Reread everything. Made minor corrections.
13 August 2009
- Moved The Physics Hypertextbook from hypertextbook.com/physics to physics.info. Added loads of redirects to reduce link rot as much as possible. Havent done' much with E-World or the other parts of Hypertextbook in the last two years.
25 May 2008
- NASA Extinct and Endangered Education Programs
How many education programs can a government agency kill in one year?
3 April 2005
- Traffic camera mosaics
Simultaneously displays images from all 80 currently working traffic cameras in New York City. Comes in two varieties: a small one for typical computer monitors and a large one for oversized monitors. Both versions refresh three times a minute.
13 August 2004
- Sounds of salone
Completely redigitized these musical selections from the original analog tapes. Gave up on RealAudio and switched over to mp3.
24 June 2003
- When is a 65 not a 65?
Grades on the New York State Regents Physics Exam have experienced significant declines that began when the first of the new format exams appeared in June 2002. It is my contention that this decline is not the result of any increase in difficulty, but instead is due primarily to a change in scoring practices that eliminated a generous bonus and replaced it with a slight penalty. Questions have not gotten significantly harder. Students have not gotten weaker. From June 1992 to January 2002, a student who answered 57% of the questions correctly was awarded a passing score of 65. To receive the same score on the June 2003 exam, a student would have to answer 67% of the questions correctly. If the new exams were graded using the old system for converting raw points into a final mark, average scores and passing rates would have stayed essentially constant.
6 October 2001
- The before & after movie
Two views of Manhattan taken from the same location, separated in time by eleven months. Watch as the World Trade Center is silently erased from the skyline.
22 June 2001
14 January 2001
- School privatization & choice
Added excepts form Justice DeGrasse's rulings in the case of Campaign for Fiscal Equity v. State of New York. "The... method for funding education in the State of New York violates... the New York State Constitution, (Article XI, Section 1)." Contains very accurate descriptions of the problems faced by students and teachers in the New York City public school system.
23 August 2000
- Salone scrapbook
3 March 2000
8 May 1999
- Salone scrapbook
25 April 1999
- The scriptural basis for a geocentric cosmology
Those who insist that biology conform to the creation myth should also insist that the earth sciences conform to a geocentric (or even flat-earth) model. The Bible describes a universe that few of us would recognize today. This position is supported with approximately 40 verses from both the Old and New Testaments. Of course, the Bible also describes a universe that was created in six terrestrial days. Why is the literal interpretation of the Bible applied so readily to the latter situation and not the former? The message here is, I think, obvious. The Bible is the literal truth only when it's convenient. In my view, this invalidates the logical core of the anti-evolutionary movement in its entirety.
15 February 1999
- Moved to hypertextbook.com from www.columbia.edu/~gae4. Applied the name E-World only to my collection of essays. Split off the other major sites and gave them their own names.
7 June 1998
- Rebel Forces Attack Magburaka
First-hand account of a February 1998 rebel attack as told by the Reverend Jim Tulley — a Catholic priest with the Xaverian Missionaries in Sierra Leone. Additional stories on his evacuation to Guinea and the kidnapping of fellow missionaries in the Northern Province. Articles reproduced here are intended for educational, non-commercial use only. Copyrights are held by the authors.
20 April 1998
- Van de Graaff generators in the classroom
Theory, safety, and operation of the 500,000 V classroom Van de Graaff generator. Written for use by teachers at Midwood High School, but the general principles and demonstrations can be adapted for use elsewhere.
11 November 1997
- Your daily horoscope: Is a piece of crap
The subtitle says it all. Horoscopes have no validity whatsoever. They predict nothing. They give meaningless advice. They are based on irrational assumptions. Most interesting of all, they disagree with one another. (Is my lucky number 713 or 761?) Astrology is not a science. Horoscopes are not weather forecasts. Anyone who reads them seriously is a fool. Don't believe me? Then try it for yourself. See what the web's eminent astrologers predicted for the earth's 500 million Aries on 11 November 1997.
20 February 1997
- Einstein's letters to Roosevelt
The letter that launched the arms race. A warning to President Roosevelt on the possibility of constructing "extremely powerful bombs of a new type" with hints that the German government might be doing just that. Addressed and dated Peconic, Long Island, August 2nd 1939, it was most likely written by Leo Szilard, the scientist who invented the chain reaction. Nevertheless, Einstein took full responsibility for its consequences, calling it "the greatest mistake" of his life. Also contains the partial text of three additional letters that Einstein wrote to FDR with a small collection of external links at the end.
?? February 1996
- This website was created sometime in February of 1996 and has been evolving slowly, but continuously, ever since. It was originally located at www.columbia.edu/~gae4. The name "E-World" is a parody of "eWorld", Apple Computers' now defunct ISP. I created E-World a day or two after eWorld went out of business.
- Four minutes, thirty-three seconds by John Cage
In honor of the late avant garde composer and philosopher of music this page "performs" the John Cage musical composition Four minutes, thirty-three seconds. Turn off all screen savers and power savers. Set your computer to its maximum volume for truest reproduction. This is my favorite page on E-World. It even won an award.
11 August 1994
- Mathematics packages: Their role in education
What impact will commercially produced mathematics packages have on math education in the United States? It's just a matter of time before such materials become ubiquitous in classrooms. Will schools teach basic algebra and other tasks when computer programs exist to do just that? The answer lies in the procedure for computing square roots by hand. No one teaches this algorithm now that nearly everyone owns a calculator. I originally wrote this article while still a student at Columbia University. For some reason I received a grade of A+. See if you can tell me why. It's good, but certainly not the Great American Novel. The visiting professor went back to Santiago, Chile without returning the graded copy.
19 July 1994
- Rolywholyover: A composition for museum by John Cage
An analysis of an exhibit at the Guggenheim-SoHo based on an idea by John Cage: the avant-garde composer and philosopher of music. It was shown briefly during the summer of 1994. The origins of Cage's use of chance operations in music and how he extended his musical philosophies to the museum. Being a physicist, I read the exhibit in relativistic terms. Space & time are both dimensions. Any work of art is a manipulation of parameters in these dimensions: the visual arts choosing one set of parameters and the musical arts another. Some external links are included at the end.
28 June 1994
- Ptolemy's Table of Chords
A historical paper on the creation of a Second Century trig table, outlining the procedure and detailing it using modern notation. It is not Lynx-friendly and the bandwidth impaired should beware as there are many large mathematical diagrams.
9 May 1994
- School privatization & choice: A sociopolitical analysis
School privatization efforts are largely driven by greed and narrow class interests and not by the desire to see real improvements in public education. The private sector — which already supplies textbooks and standardized tests — is easily implicated in the nation's educational deficiencies. Businesses and wealthy individuals stand to benefit the most from large-scale privatization efforts. Taxes will likely decrease in wealthy upper-class suburbs and opportunities will arise for capital-rich investors to reap millions of dollars in profits from a newly created Educational-Industrial Complex. Choices for the wealthy will multiply, while those for the poor and middle-class will no doubt decrease along with quality. Don't be fooled. "Choice" is code word for a system that perpetuates positions of privilege that are inherited and not earned.
5 May 1992
- SAT: Aptitude or demographics?
Find out how the philosophy behind the test's construction makes it a worthless piece of garbage. College admissions officers are better off rolling dice than using the SAT to predict student performance. Interested students can also take heart in knowing that the SAT can be broken through study. Find out why John Katzman, co-founder of the Princeton Review, said "The SAT is bullshit."
24 March 1992
- Television and the presidency
Media analysis — plain and simple. How the President of the United States appears on television affects our perceptions. Perception is reality, form is substance, the medium is the message, and so on.
Sometime in 1992
- Teacher certification offices in the United States
A list I compiled around 1992. See if you can get yourself certified in all fifty states, US territories, and the District of Columbia.