IN 1905, a scientific nobody had what he would later call his "happiest thought". If a person fell off a ladder, he would not feel his weight during his fall. Einstein: his Space and Times by Steven Gimbel published by Yale University Press R362 from www.exclusives.co.zaThis led Albert Einstein to the idea that gravity and acceleration were merely different ways of looking at the same thing. His idea would take another 10 years to develop, and would reshape our view of material reality, writes Steven Gimbel in this short, accessible biography, "and he would be celebrated for it across the entire scientific community".But not immediately. At the time, one mathematician quipped that "every boy in the streets of Göttingen knows more about four-dimensional geometry than Einstein". Gradually, though, Einstein's idea was considered worthy of discussion by the German physicist Max von Laue, who travelled specially to Bern to meet him."When Laue stepped off the train he let Einstein walk past him, certain that the young man on the platform could not be the eminent scientific mind who created the theories he came to discuss."Who was Einstein? The unknown civil servant who suddenly overhauled Newton's concepts of space, time, motion and mass was a darkish horse. Letters hidden until 1986 tell of a daughter called Lieserl whom Einstein had had by his first wife. Yet Einstein never mentioned her existence to his family or friends. In some stories, she died of scarlet fever; in others, she lived on into adulthood, blinded by the disease. Chillingly, Gimbel writes: "We do not know exactly what happened to Lieserl ... but we do know that Einstein never met his daughter."Gimbel records a life shot through with similar black holes.Born in Swabia to a failed mattress-maker and a domineering mother, Einstein was a late talker, finally breaking into speech one dinner with the words: "The soup is too hot." Asked by his relieved parents why he had not uttered a word until now, he replied: "Until now everything was in order."The fact that few people understood Einstein's theories only enhanced his cachet.In Los Angeles with Charlie Chaplin, he attended the premier of City Lights. Stunned to be mobbed by cheering fans, Einstein turned to Chaplin, who remarked: "They cheer me because they all understand me, and they cheer you because no one understands you."It's a nice coincidence that the centenary of Einstein's theory of general relativity falls at the same time as the discovery of a new pentaquark particle. What he might have made of the Large Hadron Collider's achievement is anyone's guess. Einstein died as mysteriously as he had lived, uttering a single sentence aloud in his native tongue. "Einstein's dying words were heard by one person, a night nurse who spoke no German." © The Daily TelegraphNicholas Shakespeare is the author, most recently, of Priscilla: the Hidden Life of an Englishwoman in Wartime France (Vintage)..