To keep my students on their toes, I often have a riddle that will reward them with a free lunch. One of my favorites is that PDF is 4 foot 8½ inches and that 4 foot 8 ½ inches is one of the most important numbers in American History (and world history). The answers to this question have been very intriguing. One student said that Napoleon was 4′ 8½’, although I really do now know this was important to American History.
In the early days of the railroad, each manufacturer set its own gauge (distance between the rails). This lead to over 20 different railroad gauges by the beginning of the Civil War. This was a logistical nightmare that might have changed the outcome of the war. As cargo went from one railroad to the next, it often had to be off-loaded and re-loaded. Retreating troops often had to destroy the railroad rolling stock since it would not run on the next rail line.
Congress stepped in with the building of the Trans-Continental Railroad and set 4′ 8½ inches as the standard from coast to coast. A car could be loaded in New York and not have to be unloaded until it arrived in its destination in California. Every manufacturer could still build the engines and cars, provided the wheels were the same distance apart.
The PDF part of the Riddle
The computer world has been a lot like the early railroads. Every software developer created its own proprietary formats, meaning that the format from one program was generally incompatible with the next program. Often, the format used with a given program was even incompatible with the next version of the same software. The product or content then had to be off-loaded to paper and manually reloaded into the other program.
Back in 1981, I got my first computer and everyone was saying we were going paperless. Boy was that a joke! Due to the different formats, everything still had to be printed.
Portable Document Format is the standard gauge. Developers can still have their own proprietary formats, but when the output is shared, PDF is the gauge. On October 3, 2005 the largest of the proprietary format developers, Microsoft, joined the PDF world by announcing native PDF creation in Office 12 when it is released in 2006.
Dr. John Warnock of Adobe Systems Inc. took some daring steps when releasing Adobe Acrobat and PDF. John gave away the reader and published the specifications for PDF. The tale is that some of his Board Members were beginning to wonder about his sanity. Releasing the specification may have been one of the smartest moves in the early personal computer industry. Sure, some companies became competitors with Adobe’s intellectual capital, but the published specifications allowed for standardization.
Several ISO standards have been developed around PDF. The PDF-X series creates PDF files that guarantee the output from commercial printers will exactly as intended by the designer without intervention. The ISO PDF-A (archival) standard allows creation of files with raster, text and vector formats that will be readable 50 years from now.
The new PDF-E standard creates a common output standard for PDF files from engineering drawings. A large engineering project may have files from numerous design programs. With PDF-E the output will be in one format. Imagine being able to search thousands of drawings on a project and find every place a defective bolt was used in less than 2 seconds! Imagine sending your client a 3-D rendering of their project that they can view, and tour with the free Adobe 7 Reader. Imagine managing an engineering project with almost no paper and ending up with an electronic owner’s manual that will follow the project through its useful life.
For the first time, we can board the worldwide internet railroad and not have to change cars. There are Acrobat Readers in numerous languages and for essentially every modern platform in the world. Yes, PDF is 4′ 8½’.