Science and technology drivers for future giant telescopes

Abstract

The second decade of the third millennium AD will hopefully see a new generation of ground-based telescopes, from 20- to 100-m in diameter, that will open a completely new window on the Universe. Here I review the scientific as well as technological drivers that underlie the new projects, looking at how they interact in pushing the limits of the parameter space and in driving the design requirements, and at some of the challenges they bring. As one may expect, much of the preparatory work, both design and industrial, is largely "concept independent", indicating that synergy rather than competition is the way forward (as it is already seen from the various collaborations that have been forming in the past year). While one should not underestimate the technical challenges, the promising result of many studies so far is that the only clearly identified show stopper seems to be funding.