Niels Bohr's 127th Birthday

Today, we see Google's doodled version of the atomic structure whereby an electron releases some of its energy and shifted from a higher energy state to a lower energy state.

This doodle is drawn to commemorate Niels Henrik David Bohr's 127th birthday. He was the person who suggested that electrons were actually confined into clearly defined, quantized orbits and that in order for them to move between these fixed orbits, they will have to release or absorb specific amounts of energy.