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by K. M. REESE
March 29, 2004 | A version of this story appeared in Volume 82, Issue 13




Space shots use railroad gauge

An obscure source has produced a history of the U.S. standard railroad gauge--the distance between the rails, which is 4 feet, 8.5 inches. The source says, "I think I've heard that this is really true, as opposed to being just some Internet hogwash."

In any event, the story goes, the standard gauge began with the Romans, who made their war chariots just wide enough to accommodate the back ends of two horses charging abreast (side by side). The Roman Empire spread through Europe and England, and the wheels of its chariots created the long-distance ruts that connected everything. Everybody else used the ruts, too, because the terrain was so rough. Taking off across country would have been much too hard on wheels and undercarriages.

The rut-rail spacing persisted through the centuries, from chariots to wagons to tramways to railroads. English expatriates built the U.S. rail lines, again with the old, familiar standard gauge. All through the evolution of the lines, the people who built them used the same jigs and tools, all reflecting the standard gauge.

Which brings us to the space shuttle, with the solid rocket boosters attached to the sides of its main fuel tank. The boosters (SRBs) were made by Thiokol at its factory in Utah. The engineers who designed the SRBs would have liked to make them a bit fatter, but the SRBs had to be shipped by rail from the factory to the launch site. Thus the diameter of a major feature of the space shuttle, arguably the world's most advanced transportation system, was determined more than 2,000 years ago by the width of a horse's aft end.


Drying Polaroids

Richard V. Cartwright of Burlington, Vt., writes that an important detail was omitted from remarks here about shaking Polaroid photographs (C&EN, March 8, page 216). For a long time, he says, you had to apply a coating to Polaroids to preserve the quality of the image. You applied it with a small squeegee. It smelled distinctly of acetic acid, Cartwright recalls, "and was quite sticky until it dried." He suspects that "much of the shaking that we recall was to hasten the drying of that coating."


Comments on pH

Some remarks on the symbol pH (C&EN, Feb. 9, page 64), introduced in 1909 by the Danish biochemist Søren P. L. Sørensen, included some critical comments by the U.S. chemist W. Mansfield Clark (not Clarke, as previously identified). Jay A. Young of Silver Spring, Md., writes that Clark seems later to have changed his mind. Young quotes from page 271 of the second edition of Clark's book, "Topics in Physical Chemistry" (Philadelphia: Williams & Wilkins, 1948):

"S. P. L. Sørensen of the Carlsberg Laboratory in Copenhagen had the genius to see that if a logarithmic function of the hydrogen ion concentration were used the following advantages would be gained. ... As a result of Sørensen's beautiful exposition, an understanding of the elements of the subject became clear to those who had previously ignored its potentialities."

Correspondent Young also lavishes praise on Newscripts: "It's the second thing I turn to after I have looked at everything else."


Internet warns of dihydrogen monoxide

William Terbush of Round Lake, Ill., found on the Fox News network website a story that said officials of Aliso Viejo, Calif., were thinking of banning plastic foam cups because the cups were made with dihydrogen monoxide. The goof occurred when an Aliso Viejo paralegal believed an Internet hoax site. It described dihydrogen monoxide as an "odorless, tasteless chemical" that is lethal if inhaled.

As a result, the city council of the Orange County suburb was scheduled to vote this month on a proposal that would have banned the use of Styrofoam cups at city-sponsored events. The containers were said to "threaten human health and safety."

The ban was pulled from the agenda when the facts came out, but City Manager David J. Norman termed the episode "embarrassing." He said, "We had a paralegal who did bad research."



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