For the Record

"Bubble Fusion Research Under Scrutiny" [News, May] contains incorrect and misleading criticisms of our work. Contrary to Rusi P. Taleyarkhan's claim that Brian Naranjo, in his analysis of Taleyarkhan's data, "did not model the right experiment," Naranjo's calculations do include the various sources of neutron scattering cited by Taleyarkhan. For Naranjo's complete analysis, see http://arxiv.org/pdf/physics/0603060.

Furthermore, about the bubble fusion Pyrex flask design, the article quotes Richard Lahey as saying that he has "offered to send actual design drawings so that others can build it and use it," and that our group was using a design "that was doomed to failure." The fact is that the Pyrex acoustic resonator currently in use at UCLA was built according to blueprints provided by Taleyarkhan's group.

It is regrettable that no attempt was made to contact us while reporting this article.

Brian Naranjo

Seth Putterman

Los Angeles

The writers are in the physics department at UCLA.

The editor responds: We regret not contacting the writers.

Check Denmark

"A Broadband Utopia" [May], which describes how city governments in Utah are bringing broadband to their citizens, is too U.S.-focused. In Denmark, for example, energy companies have for some years put fibers up in the air or in the ground everywhere new wires are laid. At the moment, all utility wires are being put underground to avoid storm damage, and every utility customer is being offered a 100-plus-megabit-per-second connection to telephone, TV, Internet, and other services. No public money is involved, and the prices are reasonably fair—about the same price as an 8-Mb/s asynchronous digital subscriber line. A service like television incurs an extra charge, however.

Sten Carlsen

IEEE Member

Sengeløse, Denmark

Toy Story

Andrew Carol is not alone in building Babbage's Difference Engine from toy parts [The Big Picture, April]. Tim Robinson, a Californian, is building the engine not with Legos but with Meccano, a 100-year-old building toy kit from England. The kits are still being marketed by Meccano France and are sold in the United States as Erector sets. Photos of his work are at http://www.flickr.com/photos/tbr00/favorites, and a video is at http://video.google.com/videoplay?docid=8639494575376908189.

Meccano has also been used to build an analog computer, now in a museum in New Zealand. And it was part of the tool kit used to crack the German Enigma coding machine of World War II fame.

Arup R. Dasgupta

IEEE Senior Member

Ahmedabad, India

Hearing is believing

Kudos to Rahul Sarpeshkar for the excellent article on the brain and its power consumption ["Brain Power," May]. The third part of the mechanism of hearing (which the article didn't mention) is the cognitive processing that takes place once "digitized" signals emerge from the eighth cranial nerve. I've pondered this process because I have a chronic sinus problem that affects my eustachian tubes, impairing the "analog," or mechanical, portion of my hearing.

To compensate for the degradation in frequency response, I find that I can still understand a sentence by interpolating the words that I don't hear clearly. Apparently, the brain's language center figures out the vocabulary and syntax of what the speaker is probably saying and reconstructs what it believes it has heard.

I've learned to do this pretty well with English; how­ever, for languages I don't speak as well, I have to work harder to hear the nuances in the words that sound alike. Therefore, I believe there's a bit more power consumption going on than is due just to the mechanical and neural sensations of hearing.

H. Robert Schroeder

IEEE Member

Ewing, N.J.

Not Every Hybrid

I enjoyed reading "Top 10 Tech Cars" [April]. However, this statement regarding hybrids is not quite correct: "They are most fuel-efficient in urban, stop-and-go traffic, and least economical at freeway speeds or under hard acceleration." This is true for series hybrid vehicles, such as the Toyota Prius, which can run on electricity exclusively.

My 2000 Honda Insight is a parallel hybrid and gets much better mileage on the open highway than in stop-and-go traffic. Its gasoline engine, unlike the Prius's, is always running when the car is ­moving: it cannot run without gasoline in stop-and-go traffic. At highway speeds, the Honda's three-cylinder engine is most efficient and the electric motor kicks in only when needed for extra power.

Robert G. Schaffrath

IEEE Member

Glen Head, N.Y.