# Letters

Although I'm far too young to be a curmudgeon, I found myself in full agreement with Al Bartlett's comments on the use of "presentation technology" (October 2001, APS News). I would only add that a bad presentation is a bad presentation, whether done with an overhead projector or a glitzy PowerPoint presentation. A watch-word for all presenters: view your own slides-whether on transparencies or 35mm or computer projector-from the back row of the room you'll actually be using. If you can't read it effectively, neither can your audience.
George Spagna
Ashland, Virginia

## Accuracy is Important

In the October 2001 issue of APS News, I noticed that the graphs on page 1 showing the rises in salaries for physicists did not begin at $0. In my opinion, our visual aids should illustrate the same data with the same level of accuracy as our numbers would do. However, while I am happy that my salary has continued to climb over the years, by beginning at$20,000 instead of \$0, the graphs make the increase "appear" to be larger (percentage-wise) than the numbers indicate. In this case it may not be a large "error" in perception, but as scientists we should aim to be accurate in all of our communication.
Richard L. Bowman
Bridgewater, Virginia

## Mein Units

As I started reading Charles McCutchen's Viewpoint article in the October 2001 issue of APS News, I fell into my usual 2pm power nap, a habit since post-lunch lectures in grad school. When I woke up and continued his article, I was thrilled and delighted by a level of vitriol and teeth gnashing that I'd not seen in print in many years. I was therefore a bit disappointed to find some technical errors in an article whose fury and opprobrium were otherwise perfect.

The ultracentrifugers' Svedberg is 10-13 seconds, not 10-13 cm. The subsequent parenthetic remark, "(one Fermi/sec per g)", presumably intended to shed further light on the Svedberg, works out to ~(10-15 m/sec)/(10m/sec2)=10-16 sec, off by a factor of about 1000 from the Svedberg.

I very much enjoyed reading an article that could have been entitled Mein Units. However, it's a bit ironic that significant errors in both dimensions and numbers crept into a piece that unabashedly extolled units that had not, in the author's opinion, passed muster with the "units dictators".
Jeffrey Marque
San Mateo, California

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