Telescopes of the highest quality can see light from far, far away. Galaxies and other heavenly bodies previously unknown can now be seen. Some scientists speculated that since they could see nothing in certain places, there was nothing else to be seen. By making the telescopes more sensitive to different kinds of light, parts of the sky that had been blank filled with stars and galaxies.
Sometimes we think we see it all, until the Lord shows it to us in a different light. We fall to the temptation to rely exclusively on our own judgment, even though we have access to infinite wisdom.