... Bad Astronomy . ... Radio . ... Bitesize Astronomy . ... Think of a telescope as a bucket that collects light. ... So over the years, telescope makers have focused on making telescopes bigger and bigger. ... For radio telescopes, however, the size limit is much bigger. Many astronomical objects emit radio waves, and as it happens telescopes built to detect radio don't have the same stringent smoothness criteria optical telescopes do. ... But radio telescopes can get even bigger. ...