Scientists have two ways to think about light: it can be represented as a wave or as particles called photons. It took a long time to discover that both representations were valid and for some time there had been a debate between supporters of each point of view. Nobody - or everybody - won the argument; light is both wave and particle.
The most powerful telescope on the summit on Mauna Kea is the twin Keck observatory, which has two 10 metre diameter mirrors. At the heart of each Keck Telescope is a revolutionary primary mirror made up of 36 hexagonal segments that effectively work as a single piece of reflective glass. By combining advanced optical and infrared detectors with sophisticated electronics that can combine collected light from both telescopes, the Keck observatory remains amongst the leading astronomical facilities in the world.