Voice

The basic principle of FAST is to focus the interstellar light from the depths of the universe into one point with the parabolic surface. The larger the aperture， the stronger the ability to receive light， which means greater gain and larger magnification. ”

--Chief Scientist of Department of Radio Astronomy Research， National Astronomical Observatory of CAS； Asst. Chief Engineer of FAST Project

Di LI

The Five-hundred-meter Aperture Spherical radio Telescope is hailed as "Heavenly Eye of China." As the world's largest and most sensitive radio telescopes， it has big ambitions， among which the first is to find radio pulsars outside the Milky Way. Previously， more than 2，700 pulsars found were in the Milky Way. There are a lot of radio telescopes in China before FAST， which have done plenty of basic research work， but without enough aperture diameter， none is able to find a pulsar.

Broadly speaking， FAST is like a radio， with a huge antenna， listening to the sound from the depths of the universe--the electromagnetic wave of pulsar with its whistle. The parabolic surface consisting of a lot of reflective units（250，000 square meters， equivalent to 30 football fields） is FASTs antenna. The radio antenna in our life is like a pole which can sense electromagnetic waves in all directions， but can not focus， while antenna of FAST can focus， and is more like the antenna of a satellite TV in our home.endprint