The scientific touchstones of the modern age——the Bomb, space travel, electronics, Quantum physics——all bear his imprint.

Einstein had conjured the whole business, it seemed. He did not invent the “thought experiment”, but he raised it to high art. Imagine twins , wearing identical watches; one stays home, while the other rides in a spaceship near the speed of light … little wonder that from 1919, Einstein was——and remains today——the world’s most famous scientist.

In his native Germany he became a target for hatred . As a Jew, a liberal, a humanist, an internationalist, he attracted the enmity of rationalist and anti-semites. His was now a powerful voice, widely heard, always attended to , especially after he moved to the U.S. He used it to promote zionism, pacifism, in his secret 1939 letter to Franklin D. Roosevelt, the construction of a uranium bomb.

Meanwhile, like any demigod, he made bits of legend: that he failed math in school (not true). That he opened a book and found an uncashed $1,500 check he had left as a bookmark (maybe---he was absentminded about everyday affairs).That he was careless about socks, collars, slippers … that he couldn’t even remember his address: 112 Mercer Street in Princeton, where he finally settled.

He died there in 1955 And after the rest of Einstein had been cremated, his brain remained, soaking for decades in a jar of formaldehyde belonging to Dr. Thomas Harvey. No one had bothered to dissect the brain of Freud, Stravinsky or Joyce, but in the 1980s, bits of Einsteinian gray matter were making the rounds of certain neurobiologists, who thus learned … absolutely nothing. It was just a brain——the brain that dreamed a plastic fourth dimension, that banished the ether, that released the pins binding us to absolute space and time, that refused to believe God played dice.

In embracing Einstein, our century took leave of a prior universe and an erstwhile God. The new versions were not so rigid and deterministic as the Newtonian world. Einstein’s. God was no clockmaker, but the embodiment of reason in nature. This God did not control our actions or even sit in judgment on them. (“Einstein, stop telling God what to do,” Niels Bohr Finally retorted.) This God seemed rather kindly and absentminded, as a matter of fact . Physics was free, and we too are free, in the Einstein universe which is where we live.