Google is celebrating birthday of Hans Christian Ørsted, one of the pioneer scientist of 19th century in the field of Electromagnetism. Today’s logo is made from with wires, compass, nail, and a battery to celebrate the occasion.
Hans Christian Ørsted, was born on 14th August 1777 in Rudkøbing, Denmark. In 1820, he discovered that a compass needle shows deflection when a nearby wire possess current. The unit of magnetic field strength was named as Oersted in his honor. He was a prominent chemist and Poet too. [Wiki Link]