Letters from the August 13, 2005, issue of Science News

Bay listen

It was interesting to read of processing mundane noise to produce an ultrasound image of the geology of Los Angeles (“Seismic noise can yield maps of Earth’s crust,” SN: 6/11/05, p. 382). A big question in the state is the deep structure of San Francisco Bay. Clearly, the bay and the valleys extending to its northwest and southeast form a rift valley. But it’s difficult to observe faulting in the rocks because of the depth of sediment. Maybe the area could be probed ultrasonically.

Charles B. Warren
San Francisco, Calif.

Lucy on the loose

“Faithful Ancestors: Researchers debate claims of monogamy for Lucy and her ancient kin” (SN: 6/11/05, p. 379) seems determined to impose (not very) modern cultural views on data that do not support them. Females would have benefited from a male “bringing home food”?! To the best of our knowledge Australopithecus afarensis was a foraging species, members of all ages and both sexes eating what they found as they found it. Sorry. No helpless little ladies waiting at home back then.

Nancy Parker
Caldwell, Idaho

Like a rock?

It seems to me that “Earthlike” is overused in the media (“Planet Hunt Strikes Rock: Hot kin of Earth orbits nearby star,” SN: 6/18/05, p. 387). One always ends up using too many qualifiers. Gliese 876’s orbit is very un-Earthlike, and its mass is too. Let’s wait until the star-to-planet distance of a future exoplanet ranges from that of Venus to Mars and the mass is no more than twice that of Earth or Venus. And since so little is known about Gliese 876, it’s not obvious to me that even the artist’s rendition contributes anything at this time.

Dennis Blanchard
San Jose, Calif.

Sour taste

I am shocked and incensed by the study described in “No Sugar Babies: Study suggests treating gestational diabetes” (SN: 6/18/05, p. 389). It is unconscionable that nutritional counseling for gestational diabetes was kept from pregnant mothers.

Susanna Napierala
Kenwood, Calif.