Scientists are still trying to produce a unified theory of everything, just like Einstein tried to do.
Today, the closest thing we have is the "String Theory." Because quantum mechanics is at the heart of that approach, however, it is likely something Einstein himself would have rejected.
At the end of his life, the person who produced the greatest scientific papers of the 20th century - before he was 40 years old - was a man whose life was filled with ironies.
One of the greatest ironies, in Einstein's life, is that his own early work (in 1905, Einstein theorized that light wasn’t just made up of waves, it was composed of individual particles called quanta) spawned a branch of science he grew to dislike: quantum mechanics.
From Einstein’s Unfinished Symphony, BBC Horizon, starring David Graham as Einstein and Annette Badland as his nurse - part six. Online, via BBC's WorldWide Channel at YouTube. Copyright BBC, all rights reserved. Clip provided as fair use for educational purposes and to acquaint new viewers with the production.
Note ... the cello piece (at about 4:30 into the clip) is the prelude from Season: Suite for Unaccompanied Cello, No. 1 in G Major (BWV 1007), by J.S. Bach. The concluding work is from Beethoven’s Piano Concerto in E Flat, opus 73 - “The Emperor,” part two, Adagio un poco musso.