The greatest innovation in science is the invention of experiment. For the Renaissance philosophers, it must have looked like sheer arrogance to dare forcing Nature to provide answers to well-posed questions.
Experimental observation is what distinguishes science from many other intellectual endeavours. Nature is the ultimate judge whether our ideas are correct or not. And, luckily, Nature sometimes likes to surprise us!
Anton Zeilinger is full professor of experimental physics at the University of Vienna, scientific director, Institute of Quantum Optics and Quantum Information IQOQI, Austrian Academy of Sciences.