HISTORY OF PHYSICS Michael Faraday and the first attempt of a Unified Theory. On March 19, 1849, Faraday's diary records: 'Gravity. Surely this force must be capable of an experimental relation to Electricity, Magnetism and the other forces, so as to bind it up with them in reciprocal action and equivalent effect. Consider for a moment how to set about touching this matter by facts and trial'. 1/