An expert is someone who can accurately predict how a certain technology will progress in the next 12 to 18 months. An authority can extend the prediction relatively accurately to five years or so. A visionary looks ahead 10 years or more and is either lucky or wrong. In the long run, innovation has a bad habit of upsetting the technology continuum. Photonics has had its share of experts, authorities and visionaries. We have encouraged them by publishing their thoughts. So it is with relish that we now recall them. From our perch out here at the end of 1999, it would be easy to praise those who were "right" and ridicule the rest. Instead, we should learn from this history. Use both winners and losers as examples of the two laws of the technology continuum: Only significant innovation ("paradigm shifts") can conquer market inertia. A shifting market lures research and development resources (people, money and time) and applications. These laws explain why HeNe lasers and 35-mm photographic film are still profit centers (semiconductor lasers and digital cameras have not yet broken market inertia) and why we don't yet have optical computers with holographic storage media on our desks (resources shifted to microprocessors and high-density magnetic media). Before you look ahead at what visionaries predict for our 50-year future, take a moment to see how well -- and how poorly -- we have guessed in the past.