Google secretly investing in zeppelins?Zeppelins went out of style when the Hindenburg went down in flames over New Jersey. But Airship Ventures, a startup backed by quirky angel investor Esther Dyson, is trying to bring them back. With a little help from Dyson's friends. Airship's Zeppelin NT, the first to fly over the U.S. in 70 years, has just completed a transatlantic journey and is scheduled to touch down this afternoon at the Nasa-operated Moffett Field, where it will be permanently stationed, operating aerial tours of the Bay Area. Curious — a private enterprise making use of public lands. Nasa's excuse for hosting the zeppelin: It will be used for scientific investigations and other public-spirited purposes. Where have we heard that before?Why, with the Google founders' fleet of party planes, which are also parked at Moffett Field, with the excuse that they sometimes fly scientific missions. (In fact, the Google founders' jets proved impractical for Nasa's science needs; Larry Page, Sergey Brin, and Eric Schmidt bought a fighter jet to fly those missions instead.) One of Airship Ventures' backers is an entity called Amphitheatre Holdings. Amphitheatre is incorporated in Delaware under the address of INV Tax Group, which Google may have purchased in a real-estate transaction two years ago. Google's headquarters is at 1600 Amphitheatre Parkway in Mountain View, Calif. This hardly seems like coincidence. Dyson is an investor in 23andMe, the Google-backed startup of Anne Wojcicki, wife of founder Sergey Brin. Has Dyson taken Google's shareholders for a ride, by having them take a hidden stake in a blimp startup?