I realized after I posted that bit of silliness that a straight parabola wouldn't do it. That would reflect light directly back to its origin. In order to deflect a light beam around the valley, each mirror would have to be an off-center segment of a larger parabola. But think of the savings! One simple, oh, 40 foot mirror could yield enough chunks for the whole project. Just to add a bit of real content to this missive, Chuck do any of your lasers list bandwidth as a specification? While the nature of the laser means that emitted light will have a narrow bandwidth, I can't help but think that material purity would have a big impact on coherence of that light. That it turn would have a big effect on the beam's ability to hold together over distance. And finally Ann, let me echo best wishes for your daughter. I'd seen her name and wondered if there was a connection. I don't live in SLC myself, so I can't vote, but I'll be emitting good wishes. I'm delighted to see a young person making an effort to be involved in civic life. Whatever the outcome, it's bound to be a positive experience for her. On Nov 6, 2005, at 10:56 PM, Chuck Hards wrote:

Michael, Bill Kelley would rescue this project. No need to figure a large shallow mirror...just flex a big aluminized flat mirror.

Of course, mechanical sag would probably swamp any intentional flex on something that large and that close to flat. Maybe an array of smaller mirrors would be better?